1 /*
   2  * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2012, 2018 SAP SE. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 // According to the AIX OS doc #pragma alloca must be used
  27 // with C++ compiler before referencing the function alloca()
  28 #pragma alloca
  29 
  30 // no precompiled headers
  31 #include "jvm.h"
  32 #include "classfile/classLoader.hpp"
  33 #include "classfile/systemDictionary.hpp"
  34 #include "classfile/vmSymbols.hpp"
  35 #include "code/icBuffer.hpp"
  36 #include "code/vtableStubs.hpp"
  37 #include "compiler/compileBroker.hpp"
  38 #include "interpreter/interpreter.hpp"
  39 #include "logging/log.hpp"
  40 #include "libo4.hpp"
  41 #include "libperfstat_aix.hpp"
  42 #include "libodm_aix.hpp"
  43 #include "loadlib_aix.hpp"
  44 #include "memory/allocation.inline.hpp"
  45 #include "memory/filemap.hpp"
  46 #include "misc_aix.hpp"
  47 #include "oops/oop.inline.hpp"
  48 #include "os_aix.inline.hpp"
  49 #include "os_share_aix.hpp"
  50 #include "porting_aix.hpp"
  51 #include "prims/jniFastGetField.hpp"
  52 #include "prims/jvm_misc.hpp"
  53 #include "runtime/arguments.hpp"
  54 #include "runtime/atomic.hpp"
  55 #include "runtime/extendedPC.hpp"
  56 #include "runtime/globals.hpp"
  57 #include "runtime/interfaceSupport.inline.hpp"
  58 #include "runtime/java.hpp"
  59 #include "runtime/javaCalls.hpp"
  60 #include "runtime/mutexLocker.hpp"
  61 #include "runtime/objectMonitor.hpp"
  62 #include "runtime/orderAccess.inline.hpp"
  63 #include "runtime/os.hpp"
  64 #include "runtime/osThread.hpp"
  65 #include "runtime/perfMemory.hpp"
  66 #include "runtime/sharedRuntime.hpp"
  67 #include "runtime/statSampler.hpp"
  68 #include "runtime/stubRoutines.hpp"
  69 #include "runtime/thread.inline.hpp"
  70 #include "runtime/threadCritical.hpp"
  71 #include "runtime/timer.hpp"
  72 #include "runtime/vm_version.hpp"
  73 #include "services/attachListener.hpp"
  74 #include "services/runtimeService.hpp"
  75 #include "utilities/align.hpp"
  76 #include "utilities/decoder.hpp"
  77 #include "utilities/defaultStream.hpp"
  78 #include "utilities/events.hpp"
  79 #include "utilities/growableArray.hpp"
  80 #include "utilities/vmError.hpp"
  81 
  82 // put OS-includes here (sorted alphabetically)
  83 #include <errno.h>
  84 #include <fcntl.h>
  85 #include <inttypes.h>
  86 #include <poll.h>
  87 #include <procinfo.h>
  88 #include <pthread.h>
  89 #include <pwd.h>
  90 #include <semaphore.h>
  91 #include <signal.h>
  92 #include <stdint.h>
  93 #include <stdio.h>
  94 #include <string.h>
  95 #include <unistd.h>
  96 #include <sys/ioctl.h>
  97 #include <sys/ipc.h>
  98 #include <sys/mman.h>
  99 #include <sys/resource.h>
 100 #include <sys/select.h>
 101 #include <sys/shm.h>
 102 #include <sys/socket.h>
 103 #include <sys/stat.h>
 104 #include <sys/sysinfo.h>
 105 #include <sys/systemcfg.h>
 106 #include <sys/time.h>
 107 #include <sys/times.h>
 108 #include <sys/types.h>
 109 #include <sys/utsname.h>
 110 #include <sys/vminfo.h>
 111 #include <sys/wait.h>
 112 
 113 // Missing prototypes for various system APIs.
 114 extern "C"
 115 int mread_real_time(timebasestruct_t *t, size_t size_of_timebasestruct_t);
 116 
 117 #if !defined(_AIXVERSION_610)
 118 extern "C" int getthrds64(pid_t, struct thrdentry64*, int, tid64_t*, int);
 119 extern "C" int getprocs64(procentry64*, int, fdsinfo*, int, pid_t*, int);
 120 extern "C" int getargs(procsinfo*, int, char*, int);
 121 #endif
 122 
 123 #define MAX_PATH (2 * K)
 124 
 125 // for timer info max values which include all bits
 126 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 127 // for multipage initialization error analysis (in 'g_multipage_error')
 128 #define ERROR_MP_OS_TOO_OLD                          100
 129 #define ERROR_MP_EXTSHM_ACTIVE                       101
 130 #define ERROR_MP_VMGETINFO_FAILED                    102
 131 #define ERROR_MP_VMGETINFO_CLAIMS_NO_SUPPORT_FOR_64K 103
 132 
 133 // excerpts from systemcfg.h that might be missing on older os levels
 134 #ifndef PV_5_Compat
 135   #define PV_5_Compat 0x0F8000   /* Power PC 5 */
 136 #endif
 137 #ifndef PV_6
 138   #define PV_6 0x100000          /* Power PC 6 */
 139 #endif
 140 #ifndef PV_6_1
 141   #define PV_6_1 0x100001        /* Power PC 6 DD1.x */
 142 #endif
 143 #ifndef PV_6_Compat
 144   #define PV_6_Compat 0x108000   /* Power PC 6 */
 145 #endif
 146 #ifndef PV_7
 147   #define PV_7 0x200000          /* Power PC 7 */
 148 #endif
 149 #ifndef PV_7_Compat
 150   #define PV_7_Compat 0x208000   /* Power PC 7 */
 151 #endif
 152 #ifndef PV_8
 153   #define PV_8 0x300000          /* Power PC 8 */
 154 #endif
 155 #ifndef PV_8_Compat
 156   #define PV_8_Compat 0x308000   /* Power PC 8 */
 157 #endif
 158 
 159 static address resolve_function_descriptor_to_code_pointer(address p);
 160 
 161 static void vmembk_print_on(outputStream* os);
 162 
 163 ////////////////////////////////////////////////////////////////////////////////
 164 // global variables (for a description see os_aix.hpp)
 165 
 166 julong    os::Aix::_physical_memory = 0;
 167 
 168 pthread_t os::Aix::_main_thread = ((pthread_t)0);
 169 int       os::Aix::_page_size = -1;
 170 
 171 // -1 = uninitialized, 0 if AIX, 1 if OS/400 pase
 172 int       os::Aix::_on_pase = -1;
 173 
 174 // 0 = uninitialized, otherwise 32 bit number:
 175 //  0xVVRRTTSS
 176 //  VV - major version
 177 //  RR - minor version
 178 //  TT - tech level, if known, 0 otherwise
 179 //  SS - service pack, if known, 0 otherwise
 180 uint32_t  os::Aix::_os_version = 0;
 181 
 182 // -1 = uninitialized, 0 - no, 1 - yes
 183 int       os::Aix::_xpg_sus_mode = -1;
 184 
 185 // -1 = uninitialized, 0 - no, 1 - yes
 186 int       os::Aix::_extshm = -1;
 187 
 188 ////////////////////////////////////////////////////////////////////////////////
 189 // local variables
 190 
 191 static volatile jlong max_real_time = 0;
 192 static jlong    initial_time_count = 0;
 193 static int      clock_tics_per_sec = 100;
 194 static sigset_t check_signal_done;         // For diagnostics to print a message once (see run_periodic_checks)
 195 static bool     check_signals      = true;
 196 static int      SR_signum          = SIGUSR2; // Signal used to suspend/resume a thread (must be > SIGSEGV, see 4355769)
 197 static sigset_t SR_sigset;
 198 
 199 // Process break recorded at startup.
 200 static address g_brk_at_startup = NULL;
 201 
 202 // This describes the state of multipage support of the underlying
 203 // OS. Note that this is of no interest to the outsize world and
 204 // therefore should not be defined in AIX class.
 205 //
 206 // AIX supports four different page sizes - 4K, 64K, 16MB, 16GB. The
 207 // latter two (16M "large" resp. 16G "huge" pages) require special
 208 // setup and are normally not available.
 209 //
 210 // AIX supports multiple page sizes per process, for:
 211 //  - Stack (of the primordial thread, so not relevant for us)
 212 //  - Data - data, bss, heap, for us also pthread stacks
 213 //  - Text - text code
 214 //  - shared memory
 215 //
 216 // Default page sizes can be set via linker options (-bdatapsize, -bstacksize, ...)
 217 // and via environment variable LDR_CNTRL (DATAPSIZE, STACKPSIZE, ...).
 218 //
 219 // For shared memory, page size can be set dynamically via
 220 // shmctl(). Different shared memory regions can have different page
 221 // sizes.
 222 //
 223 // More information can be found at AIBM info center:
 224 //   http://publib.boulder.ibm.com/infocenter/aix/v6r1/index.jsp?topic=/com.ibm.aix.prftungd/doc/prftungd/multiple_page_size_app_support.htm
 225 //
 226 static struct {
 227   size_t pagesize;            // sysconf _SC_PAGESIZE (4K)
 228   size_t datapsize;           // default data page size (LDR_CNTRL DATAPSIZE)
 229   size_t shmpsize;            // default shared memory page size (LDR_CNTRL SHMPSIZE)
 230   size_t pthr_stack_pagesize; // stack page size of pthread threads
 231   size_t textpsize;           // default text page size (LDR_CNTRL STACKPSIZE)
 232   bool can_use_64K_pages;     // True if we can alloc 64K pages dynamically with Sys V shm.
 233   bool can_use_16M_pages;     // True if we can alloc 16M pages dynamically with Sys V shm.
 234   int error;                  // Error describing if something went wrong at multipage init.
 235 } g_multipage_support = {
 236   (size_t) -1,
 237   (size_t) -1,
 238   (size_t) -1,
 239   (size_t) -1,
 240   (size_t) -1,
 241   false, false,
 242   0
 243 };
 244 
 245 // We must not accidentally allocate memory close to the BRK - even if
 246 // that would work - because then we prevent the BRK segment from
 247 // growing which may result in a malloc OOM even though there is
 248 // enough memory. The problem only arises if we shmat() or mmap() at
 249 // a specific wish address, e.g. to place the heap in a
 250 // compressed-oops-friendly way.
 251 static bool is_close_to_brk(address a) {
 252   assert0(g_brk_at_startup != NULL);
 253   if (a >= g_brk_at_startup &&
 254       a < (g_brk_at_startup + MaxExpectedDataSegmentSize)) {
 255     return true;
 256   }
 257   return false;
 258 }
 259 
 260 julong os::available_memory() {
 261   return Aix::available_memory();
 262 }
 263 
 264 julong os::Aix::available_memory() {
 265   // Avoid expensive API call here, as returned value will always be null.
 266   if (os::Aix::on_pase()) {
 267     return 0x0LL;
 268   }
 269   os::Aix::meminfo_t mi;
 270   if (os::Aix::get_meminfo(&mi)) {
 271     return mi.real_free;
 272   } else {
 273     return ULONG_MAX;
 274   }
 275 }
 276 
 277 julong os::physical_memory() {
 278   return Aix::physical_memory();
 279 }
 280 
 281 // Return true if user is running as root.
 282 
 283 bool os::have_special_privileges() {
 284   static bool init = false;
 285   static bool privileges = false;
 286   if (!init) {
 287     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 288     init = true;
 289   }
 290   return privileges;
 291 }
 292 
 293 // Helper function, emulates disclaim64 using multiple 32bit disclaims
 294 // because we cannot use disclaim64() on AS/400 and old AIX releases.
 295 static bool my_disclaim64(char* addr, size_t size) {
 296 
 297   if (size == 0) {
 298     return true;
 299   }
 300 
 301   // Maximum size 32bit disclaim() accepts. (Theoretically 4GB, but I just do not trust that.)
 302   const unsigned int maxDisclaimSize = 0x40000000;
 303 
 304   const unsigned int numFullDisclaimsNeeded = (size / maxDisclaimSize);
 305   const unsigned int lastDisclaimSize = (size % maxDisclaimSize);
 306 
 307   char* p = addr;
 308 
 309   for (int i = 0; i < numFullDisclaimsNeeded; i ++) {
 310     if (::disclaim(p, maxDisclaimSize, DISCLAIM_ZEROMEM) != 0) {
 311       trcVerbose("Cannot disclaim %p - %p (errno %d)\n", p, p + maxDisclaimSize, errno);
 312       return false;
 313     }
 314     p += maxDisclaimSize;
 315   }
 316 
 317   if (lastDisclaimSize > 0) {
 318     if (::disclaim(p, lastDisclaimSize, DISCLAIM_ZEROMEM) != 0) {
 319       trcVerbose("Cannot disclaim %p - %p (errno %d)\n", p, p + lastDisclaimSize, errno);
 320       return false;
 321     }
 322   }
 323 
 324   return true;
 325 }
 326 
 327 // Cpu architecture string
 328 #if defined(PPC32)
 329 static char cpu_arch[] = "ppc";
 330 #elif defined(PPC64)
 331 static char cpu_arch[] = "ppc64";
 332 #else
 333 #error Add appropriate cpu_arch setting
 334 #endif
 335 
 336 // Wrap the function "vmgetinfo" which is not available on older OS releases.
 337 static int checked_vmgetinfo(void *out, int command, int arg) {
 338   if (os::Aix::on_pase() && os::Aix::os_version_short() < 0x0601) {
 339     guarantee(false, "cannot call vmgetinfo on AS/400 older than V6R1");
 340   }
 341   return ::vmgetinfo(out, command, arg);
 342 }
 343 
 344 // Given an address, returns the size of the page backing that address.
 345 size_t os::Aix::query_pagesize(void* addr) {
 346 
 347   if (os::Aix::on_pase() && os::Aix::os_version_short() < 0x0601) {
 348     // AS/400 older than V6R1: no vmgetinfo here, default to 4K
 349     return 4*K;
 350   }
 351 
 352   vm_page_info pi;
 353   pi.addr = (uint64_t)addr;
 354   if (checked_vmgetinfo(&pi, VM_PAGE_INFO, sizeof(pi)) == 0) {
 355     return pi.pagesize;
 356   } else {
 357     assert(false, "vmgetinfo failed to retrieve page size");
 358     return 4*K;
 359   }
 360 }
 361 
 362 void os::Aix::initialize_system_info() {
 363 
 364   // Get the number of online(logical) cpus instead of configured.
 365   os::_processor_count = sysconf(_SC_NPROCESSORS_ONLN);
 366   assert(_processor_count > 0, "_processor_count must be > 0");
 367 
 368   // Retrieve total physical storage.
 369   os::Aix::meminfo_t mi;
 370   if (!os::Aix::get_meminfo(&mi)) {
 371     assert(false, "os::Aix::get_meminfo failed.");
 372   }
 373   _physical_memory = (julong) mi.real_total;
 374 }
 375 
 376 // Helper function for tracing page sizes.
 377 static const char* describe_pagesize(size_t pagesize) {
 378   switch (pagesize) {
 379     case 4*K : return "4K";
 380     case 64*K: return "64K";
 381     case 16*M: return "16M";
 382     case 16*G: return "16G";
 383     default:
 384       assert(false, "surprise");
 385       return "??";
 386   }
 387 }
 388 
 389 // Probe OS for multipage support.
 390 // Will fill the global g_multipage_support structure.
 391 // Must be called before calling os::large_page_init().
 392 static void query_multipage_support() {
 393 
 394   guarantee(g_multipage_support.pagesize == -1,
 395             "do not call twice");
 396 
 397   g_multipage_support.pagesize = ::sysconf(_SC_PAGESIZE);
 398 
 399   // This really would surprise me.
 400   assert(g_multipage_support.pagesize == 4*K, "surprise!");
 401 
 402   // Query default data page size (default page size for C-Heap, pthread stacks and .bss).
 403   // Default data page size is defined either by linker options (-bdatapsize)
 404   // or by environment variable LDR_CNTRL (suboption DATAPSIZE). If none is given,
 405   // default should be 4K.
 406   {
 407     void* p = ::malloc(16*M);
 408     g_multipage_support.datapsize = os::Aix::query_pagesize(p);
 409     ::free(p);
 410   }
 411 
 412   // Query default shm page size (LDR_CNTRL SHMPSIZE).
 413   // Note that this is pure curiosity. We do not rely on default page size but set
 414   // our own page size after allocated.
 415   {
 416     const int shmid = ::shmget(IPC_PRIVATE, 1, IPC_CREAT | S_IRUSR | S_IWUSR);
 417     guarantee(shmid != -1, "shmget failed");
 418     void* p = ::shmat(shmid, NULL, 0);
 419     ::shmctl(shmid, IPC_RMID, NULL);
 420     guarantee(p != (void*) -1, "shmat failed");
 421     g_multipage_support.shmpsize = os::Aix::query_pagesize(p);
 422     ::shmdt(p);
 423   }
 424 
 425   // Before querying the stack page size, make sure we are not running as primordial
 426   // thread (because primordial thread's stack may have different page size than
 427   // pthread thread stacks). Running a VM on the primordial thread won't work for a
 428   // number of reasons so we may just as well guarantee it here.
 429   guarantee0(!os::is_primordial_thread());
 430 
 431   // Query pthread stack page size. Should be the same as data page size because
 432   // pthread stacks are allocated from C-Heap.
 433   {
 434     int dummy = 0;
 435     g_multipage_support.pthr_stack_pagesize = os::Aix::query_pagesize(&dummy);
 436   }
 437 
 438   // Query default text page size (LDR_CNTRL TEXTPSIZE).
 439   {
 440     address any_function =
 441       resolve_function_descriptor_to_code_pointer((address)describe_pagesize);
 442     g_multipage_support.textpsize = os::Aix::query_pagesize(any_function);
 443   }
 444 
 445   // Now probe for support of 64K pages and 16M pages.
 446 
 447   // Before OS/400 V6R1, there is no support for pages other than 4K.
 448   if (os::Aix::on_pase_V5R4_or_older()) {
 449     trcVerbose("OS/400 < V6R1 - no large page support.");
 450     g_multipage_support.error = ERROR_MP_OS_TOO_OLD;
 451     goto query_multipage_support_end;
 452   }
 453 
 454   // Now check which page sizes the OS claims it supports, and of those, which actually can be used.
 455   {
 456     const int MAX_PAGE_SIZES = 4;
 457     psize_t sizes[MAX_PAGE_SIZES];
 458     const int num_psizes = checked_vmgetinfo(sizes, VMINFO_GETPSIZES, MAX_PAGE_SIZES);
 459     if (num_psizes == -1) {
 460       trcVerbose("vmgetinfo(VMINFO_GETPSIZES) failed (errno: %d)", errno);
 461       trcVerbose("disabling multipage support.");
 462       g_multipage_support.error = ERROR_MP_VMGETINFO_FAILED;
 463       goto query_multipage_support_end;
 464     }
 465     guarantee(num_psizes > 0, "vmgetinfo(.., VMINFO_GETPSIZES, ...) failed.");
 466     assert(num_psizes <= MAX_PAGE_SIZES, "Surprise! more than 4 page sizes?");
 467     trcVerbose("vmgetinfo(.., VMINFO_GETPSIZES, ...) returns %d supported page sizes: ", num_psizes);
 468     for (int i = 0; i < num_psizes; i ++) {
 469       trcVerbose(" %s ", describe_pagesize(sizes[i]));
 470     }
 471 
 472     // Can we use 64K, 16M pages?
 473     for (int i = 0; i < num_psizes; i ++) {
 474       const size_t pagesize = sizes[i];
 475       if (pagesize != 64*K && pagesize != 16*M) {
 476         continue;
 477       }
 478       bool can_use = false;
 479       trcVerbose("Probing support for %s pages...", describe_pagesize(pagesize));
 480       const int shmid = ::shmget(IPC_PRIVATE, pagesize,
 481         IPC_CREAT | S_IRUSR | S_IWUSR);
 482       guarantee0(shmid != -1); // Should always work.
 483       // Try to set pagesize.
 484       struct shmid_ds shm_buf = { 0 };
 485       shm_buf.shm_pagesize = pagesize;
 486       if (::shmctl(shmid, SHM_PAGESIZE, &shm_buf) != 0) {
 487         const int en = errno;
 488         ::shmctl(shmid, IPC_RMID, NULL); // As early as possible!
 489         trcVerbose("shmctl(SHM_PAGESIZE) failed with errno=%n",
 490           errno);
 491       } else {
 492         // Attach and double check pageisze.
 493         void* p = ::shmat(shmid, NULL, 0);
 494         ::shmctl(shmid, IPC_RMID, NULL); // As early as possible!
 495         guarantee0(p != (void*) -1); // Should always work.
 496         const size_t real_pagesize = os::Aix::query_pagesize(p);
 497         if (real_pagesize != pagesize) {
 498           trcVerbose("real page size (0x%llX) differs.", real_pagesize);
 499         } else {
 500           can_use = true;
 501         }
 502         ::shmdt(p);
 503       }
 504       trcVerbose("Can use: %s", (can_use ? "yes" : "no"));
 505       if (pagesize == 64*K) {
 506         g_multipage_support.can_use_64K_pages = can_use;
 507       } else if (pagesize == 16*M) {
 508         g_multipage_support.can_use_16M_pages = can_use;
 509       }
 510     }
 511 
 512   } // end: check which pages can be used for shared memory
 513 
 514 query_multipage_support_end:
 515 
 516   trcVerbose("base page size (sysconf _SC_PAGESIZE): %s",
 517       describe_pagesize(g_multipage_support.pagesize));
 518   trcVerbose("Data page size (C-Heap, bss, etc): %s",
 519       describe_pagesize(g_multipage_support.datapsize));
 520   trcVerbose("Text page size: %s",
 521       describe_pagesize(g_multipage_support.textpsize));
 522   trcVerbose("Thread stack page size (pthread): %s",
 523       describe_pagesize(g_multipage_support.pthr_stack_pagesize));
 524   trcVerbose("Default shared memory page size: %s",
 525       describe_pagesize(g_multipage_support.shmpsize));
 526   trcVerbose("Can use 64K pages dynamically with shared meory: %s",
 527       (g_multipage_support.can_use_64K_pages ? "yes" :"no"));
 528   trcVerbose("Can use 16M pages dynamically with shared memory: %s",
 529       (g_multipage_support.can_use_16M_pages ? "yes" :"no"));
 530   trcVerbose("Multipage error details: %d",
 531       g_multipage_support.error);
 532 
 533   // sanity checks
 534   assert0(g_multipage_support.pagesize == 4*K);
 535   assert0(g_multipage_support.datapsize == 4*K || g_multipage_support.datapsize == 64*K);
 536   assert0(g_multipage_support.textpsize == 4*K || g_multipage_support.textpsize == 64*K);
 537   assert0(g_multipage_support.pthr_stack_pagesize == g_multipage_support.datapsize);
 538   assert0(g_multipage_support.shmpsize == 4*K || g_multipage_support.shmpsize == 64*K);
 539 
 540 }
 541 
 542 void os::init_system_properties_values() {
 543 
 544 #define DEFAULT_LIBPATH "/lib:/usr/lib"
 545 #define EXTENSIONS_DIR  "/lib/ext"
 546 
 547   // Buffer that fits several sprintfs.
 548   // Note that the space for the trailing null is provided
 549   // by the nulls included by the sizeof operator.
 550   const size_t bufsize =
 551     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 552          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR)); // extensions dir
 553   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 554 
 555   // sysclasspath, java_home, dll_dir
 556   {
 557     char *pslash;
 558     os::jvm_path(buf, bufsize);
 559 
 560     // Found the full path to libjvm.so.
 561     // Now cut the path to <java_home>/jre if we can.
 562     pslash = strrchr(buf, '/');
 563     if (pslash != NULL) {
 564       *pslash = '\0';            // Get rid of /libjvm.so.
 565     }
 566     pslash = strrchr(buf, '/');
 567     if (pslash != NULL) {
 568       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 569     }
 570     Arguments::set_dll_dir(buf);
 571 
 572     if (pslash != NULL) {
 573       pslash = strrchr(buf, '/');
 574       if (pslash != NULL) {
 575         *pslash = '\0';        // Get rid of /lib.
 576       }
 577     }
 578     Arguments::set_java_home(buf);
 579     set_boot_path('/', ':');
 580   }
 581 
 582   // Where to look for native libraries.
 583 
 584   // On Aix we get the user setting of LIBPATH.
 585   // Eventually, all the library path setting will be done here.
 586   // Get the user setting of LIBPATH.
 587   const char *v = ::getenv("LIBPATH");
 588   const char *v_colon = ":";
 589   if (v == NULL) { v = ""; v_colon = ""; }
 590 
 591   // Concatenate user and invariant part of ld_library_path.
 592   // That's +1 for the colon and +1 for the trailing '\0'.
 593   char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, strlen(v) + 1 + sizeof(DEFAULT_LIBPATH) + 1, mtInternal);
 594   sprintf(ld_library_path, "%s%s" DEFAULT_LIBPATH, v, v_colon);
 595   Arguments::set_library_path(ld_library_path);
 596   FREE_C_HEAP_ARRAY(char, ld_library_path);
 597 
 598   // Extensions directories.
 599   sprintf(buf, "%s" EXTENSIONS_DIR, Arguments::get_java_home());
 600   Arguments::set_ext_dirs(buf);
 601 
 602   FREE_C_HEAP_ARRAY(char, buf);
 603 
 604 #undef DEFAULT_LIBPATH
 605 #undef EXTENSIONS_DIR
 606 }
 607 
 608 ////////////////////////////////////////////////////////////////////////////////
 609 // breakpoint support
 610 
 611 void os::breakpoint() {
 612   BREAKPOINT;
 613 }
 614 
 615 extern "C" void breakpoint() {
 616   // use debugger to set breakpoint here
 617 }
 618 
 619 ////////////////////////////////////////////////////////////////////////////////
 620 // signal support
 621 
 622 debug_only(static bool signal_sets_initialized = false);
 623 static sigset_t unblocked_sigs, vm_sigs;
 624 
 625 bool os::Aix::is_sig_ignored(int sig) {
 626   struct sigaction oact;
 627   sigaction(sig, (struct sigaction*)NULL, &oact);
 628   void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
 629     : CAST_FROM_FN_PTR(void*, oact.sa_handler);
 630   if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
 631     return true;
 632   } else {
 633     return false;
 634   }
 635 }
 636 
 637 void os::Aix::signal_sets_init() {
 638   // Should also have an assertion stating we are still single-threaded.
 639   assert(!signal_sets_initialized, "Already initialized");
 640   // Fill in signals that are necessarily unblocked for all threads in
 641   // the VM. Currently, we unblock the following signals:
 642   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 643   //                         by -Xrs (=ReduceSignalUsage));
 644   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 645   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 646   // the dispositions or masks wrt these signals.
 647   // Programs embedding the VM that want to use the above signals for their
 648   // own purposes must, at this time, use the "-Xrs" option to prevent
 649   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 650   // (See bug 4345157, and other related bugs).
 651   // In reality, though, unblocking these signals is really a nop, since
 652   // these signals are not blocked by default.
 653   sigemptyset(&unblocked_sigs);
 654   sigaddset(&unblocked_sigs, SIGILL);
 655   sigaddset(&unblocked_sigs, SIGSEGV);
 656   sigaddset(&unblocked_sigs, SIGBUS);
 657   sigaddset(&unblocked_sigs, SIGFPE);
 658   sigaddset(&unblocked_sigs, SIGTRAP);
 659   sigaddset(&unblocked_sigs, SR_signum);
 660 
 661   if (!ReduceSignalUsage) {
 662    if (!os::Aix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 663      sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 664    }
 665    if (!os::Aix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 666      sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 667    }
 668    if (!os::Aix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 669      sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 670    }
 671   }
 672   // Fill in signals that are blocked by all but the VM thread.
 673   sigemptyset(&vm_sigs);
 674   if (!ReduceSignalUsage)
 675     sigaddset(&vm_sigs, BREAK_SIGNAL);
 676   debug_only(signal_sets_initialized = true);
 677 }
 678 
 679 // These are signals that are unblocked while a thread is running Java.
 680 // (For some reason, they get blocked by default.)
 681 sigset_t* os::Aix::unblocked_signals() {
 682   assert(signal_sets_initialized, "Not initialized");
 683   return &unblocked_sigs;
 684 }
 685 
 686 // These are the signals that are blocked while a (non-VM) thread is
 687 // running Java. Only the VM thread handles these signals.
 688 sigset_t* os::Aix::vm_signals() {
 689   assert(signal_sets_initialized, "Not initialized");
 690   return &vm_sigs;
 691 }
 692 
 693 void os::Aix::hotspot_sigmask(Thread* thread) {
 694 
 695   //Save caller's signal mask before setting VM signal mask
 696   sigset_t caller_sigmask;
 697   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 698 
 699   OSThread* osthread = thread->osthread();
 700   osthread->set_caller_sigmask(caller_sigmask);
 701 
 702   pthread_sigmask(SIG_UNBLOCK, os::Aix::unblocked_signals(), NULL);
 703 
 704   if (!ReduceSignalUsage) {
 705     if (thread->is_VM_thread()) {
 706       // Only the VM thread handles BREAK_SIGNAL ...
 707       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 708     } else {
 709       // ... all other threads block BREAK_SIGNAL
 710       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 711     }
 712   }
 713 }
 714 
 715 // retrieve memory information.
 716 // Returns false if something went wrong;
 717 // content of pmi undefined in this case.
 718 bool os::Aix::get_meminfo(meminfo_t* pmi) {
 719 
 720   assert(pmi, "get_meminfo: invalid parameter");
 721 
 722   memset(pmi, 0, sizeof(meminfo_t));
 723 
 724   if (os::Aix::on_pase()) {
 725     // On PASE, use the libo4 porting library.
 726 
 727     unsigned long long virt_total = 0;
 728     unsigned long long real_total = 0;
 729     unsigned long long real_free = 0;
 730     unsigned long long pgsp_total = 0;
 731     unsigned long long pgsp_free = 0;
 732     if (libo4::get_memory_info(&virt_total, &real_total, &real_free, &pgsp_total, &pgsp_free)) {
 733       pmi->virt_total = virt_total;
 734       pmi->real_total = real_total;
 735       pmi->real_free = real_free;
 736       pmi->pgsp_total = pgsp_total;
 737       pmi->pgsp_free = pgsp_free;
 738       return true;
 739     }
 740     return false;
 741 
 742   } else {
 743 
 744     // On AIX, I use the (dynamically loaded) perfstat library to retrieve memory statistics
 745     // See:
 746     // http://publib.boulder.ibm.com/infocenter/systems/index.jsp
 747     //        ?topic=/com.ibm.aix.basetechref/doc/basetrf1/perfstat_memtot.htm
 748     // http://publib.boulder.ibm.com/infocenter/systems/index.jsp
 749     //        ?topic=/com.ibm.aix.files/doc/aixfiles/libperfstat.h.htm
 750 
 751     perfstat_memory_total_t psmt;
 752     memset (&psmt, '\0', sizeof(psmt));
 753     const int rc = libperfstat::perfstat_memory_total(NULL, &psmt, sizeof(psmt), 1);
 754     if (rc == -1) {
 755       trcVerbose("perfstat_memory_total() failed (errno=%d)", errno);
 756       assert(0, "perfstat_memory_total() failed");
 757       return false;
 758     }
 759 
 760     assert(rc == 1, "perfstat_memory_total() - weird return code");
 761 
 762     // excerpt from
 763     // http://publib.boulder.ibm.com/infocenter/systems/index.jsp
 764     //        ?topic=/com.ibm.aix.files/doc/aixfiles/libperfstat.h.htm
 765     // The fields of perfstat_memory_total_t:
 766     // u_longlong_t virt_total         Total virtual memory (in 4 KB pages).
 767     // u_longlong_t real_total         Total real memory (in 4 KB pages).
 768     // u_longlong_t real_free          Free real memory (in 4 KB pages).
 769     // u_longlong_t pgsp_total         Total paging space (in 4 KB pages).
 770     // u_longlong_t pgsp_free          Free paging space (in 4 KB pages).
 771 
 772     pmi->virt_total = psmt.virt_total * 4096;
 773     pmi->real_total = psmt.real_total * 4096;
 774     pmi->real_free = psmt.real_free * 4096;
 775     pmi->pgsp_total = psmt.pgsp_total * 4096;
 776     pmi->pgsp_free = psmt.pgsp_free * 4096;
 777 
 778     return true;
 779 
 780   }
 781 } // end os::Aix::get_meminfo
 782 
 783 //////////////////////////////////////////////////////////////////////////////
 784 // create new thread
 785 
 786 // Thread start routine for all newly created threads
 787 static void *thread_native_entry(Thread *thread) {
 788 
 789   // find out my own stack dimensions
 790   {
 791     // actually, this should do exactly the same as thread->record_stack_base_and_size...
 792     thread->set_stack_base(os::current_stack_base());
 793     thread->set_stack_size(os::current_stack_size());
 794   }
 795 
 796   const pthread_t pthread_id = ::pthread_self();
 797   const tid_t kernel_thread_id = ::thread_self();
 798 
 799   LogTarget(Info, os, thread) lt;
 800   if (lt.is_enabled()) {
 801     address low_address = thread->stack_end();
 802     address high_address = thread->stack_base();
 803     lt.print("Thread is alive (tid: " UINTX_FORMAT ", kernel thread id: " UINTX_FORMAT
 804              ", stack [" PTR_FORMAT " - " PTR_FORMAT " (" SIZE_FORMAT "k using %uk pages)).",
 805              os::current_thread_id(), (uintx) kernel_thread_id, low_address, high_address,
 806              (high_address - low_address) / K, os::Aix::query_pagesize(low_address) / K);
 807   }
 808 
 809   // Normally, pthread stacks on AIX live in the data segment (are allocated with malloc()
 810   // by the pthread library). In rare cases, this may not be the case, e.g. when third-party
 811   // tools hook pthread_create(). In this case, we may run into problems establishing
 812   // guard pages on those stacks, because the stacks may reside in memory which is not
 813   // protectable (shmated).
 814   if (thread->stack_base() > ::sbrk(0)) {
 815     log_warning(os, thread)("Thread stack not in data segment.");
 816   }
 817 
 818   // Try to randomize the cache line index of hot stack frames.
 819   // This helps when threads of the same stack traces evict each other's
 820   // cache lines. The threads can be either from the same JVM instance, or
 821   // from different JVM instances. The benefit is especially true for
 822   // processors with hyperthreading technology.
 823 
 824   static int counter = 0;
 825   int pid = os::current_process_id();
 826   alloca(((pid ^ counter++) & 7) * 128);
 827 
 828   thread->initialize_thread_current();
 829 
 830   OSThread* osthread = thread->osthread();
 831 
 832   // Thread_id is pthread id.
 833   osthread->set_thread_id(pthread_id);
 834 
 835   // .. but keep kernel thread id too for diagnostics
 836   osthread->set_kernel_thread_id(kernel_thread_id);
 837 
 838   // Initialize signal mask for this thread.
 839   os::Aix::hotspot_sigmask(thread);
 840 
 841   // Initialize floating point control register.
 842   os::Aix::init_thread_fpu_state();
 843 
 844   assert(osthread->get_state() == RUNNABLE, "invalid os thread state");
 845 
 846   // Call one more level start routine.
 847   thread->run();
 848 
 849   log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", kernel thread id: " UINTX_FORMAT ").",
 850     os::current_thread_id(), (uintx) kernel_thread_id);
 851 
 852   // If a thread has not deleted itself ("delete this") as part of its
 853   // termination sequence, we have to ensure thread-local-storage is
 854   // cleared before we actually terminate. No threads should ever be
 855   // deleted asynchronously with respect to their termination.
 856   if (Thread::current_or_null_safe() != NULL) {
 857     assert(Thread::current_or_null_safe() == thread, "current thread is wrong");
 858     thread->clear_thread_current();
 859   }
 860 
 861   return 0;
 862 }
 863 
 864 bool os::create_thread(Thread* thread, ThreadType thr_type,
 865                        size_t req_stack_size) {
 866 
 867   assert(thread->osthread() == NULL, "caller responsible");
 868 
 869   // Allocate the OSThread object.
 870   OSThread* osthread = new OSThread(NULL, NULL);
 871   if (osthread == NULL) {
 872     return false;
 873   }
 874 
 875   // Set the correct thread state.
 876   osthread->set_thread_type(thr_type);
 877 
 878   // Initial state is ALLOCATED but not INITIALIZED
 879   osthread->set_state(ALLOCATED);
 880 
 881   thread->set_osthread(osthread);
 882 
 883   // Init thread attributes.
 884   pthread_attr_t attr;
 885   pthread_attr_init(&attr);
 886   guarantee(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) == 0, "???");
 887 
 888   // Make sure we run in 1:1 kernel-user-thread mode.
 889   if (os::Aix::on_aix()) {
 890     guarantee(pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM) == 0, "???");
 891     guarantee(pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED) == 0, "???");
 892   }
 893 
 894   // Start in suspended state, and in os::thread_start, wake the thread up.
 895   guarantee(pthread_attr_setsuspendstate_np(&attr, PTHREAD_CREATE_SUSPENDED_NP) == 0, "???");
 896 
 897   // Calculate stack size if it's not specified by caller.
 898   size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
 899 
 900   // JDK-8187028: It was observed that on some configurations (4K backed thread stacks)
 901   // the real thread stack size may be smaller than the requested stack size, by as much as 64K.
 902   // This very much looks like a pthread lib error. As a workaround, increase the stack size
 903   // by 64K for small thread stacks (arbitrarily choosen to be < 4MB)
 904   if (stack_size < 4096 * K) {
 905     stack_size += 64 * K;
 906   }
 907 
 908   // On Aix, pthread_attr_setstacksize fails with huge values and leaves the
 909   // thread size in attr unchanged. If this is the minimal stack size as set
 910   // by pthread_attr_init this leads to crashes after thread creation. E.g. the
 911   // guard pages might not fit on the tiny stack created.
 912   int ret = pthread_attr_setstacksize(&attr, stack_size);
 913   if (ret != 0) {
 914     log_warning(os, thread)("The thread stack size specified is invalid: " SIZE_FORMAT "k",
 915                             stack_size / K);
 916   }
 917 
 918   // Save some cycles and a page by disabling OS guard pages where we have our own
 919   // VM guard pages (in java threads). For other threads, keep system default guard
 920   // pages in place.
 921   if (thr_type == java_thread || thr_type == compiler_thread) {
 922     ret = pthread_attr_setguardsize(&attr, 0);
 923   }
 924 
 925   pthread_t tid = 0;
 926   if (ret == 0) {
 927     ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
 928   }
 929 
 930   if (ret == 0) {
 931     char buf[64];
 932     log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
 933       (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 934   } else {
 935     char buf[64];
 936     log_warning(os, thread)("Failed to start thread - pthread_create failed (%d=%s) for attributes: %s.",
 937       ret, os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 938   }
 939 
 940   pthread_attr_destroy(&attr);
 941 
 942   if (ret != 0) {
 943     // Need to clean up stuff we've allocated so far.
 944     thread->set_osthread(NULL);
 945     delete osthread;
 946     return false;
 947   }
 948 
 949   // OSThread::thread_id is the pthread id.
 950   osthread->set_thread_id(tid);
 951 
 952   return true;
 953 }
 954 
 955 /////////////////////////////////////////////////////////////////////////////
 956 // attach existing thread
 957 
 958 // bootstrap the main thread
 959 bool os::create_main_thread(JavaThread* thread) {
 960   assert(os::Aix::_main_thread == pthread_self(), "should be called inside main thread");
 961   return create_attached_thread(thread);
 962 }
 963 
 964 bool os::create_attached_thread(JavaThread* thread) {
 965 #ifdef ASSERT
 966     thread->verify_not_published();
 967 #endif
 968 
 969   // Allocate the OSThread object
 970   OSThread* osthread = new OSThread(NULL, NULL);
 971 
 972   if (osthread == NULL) {
 973     return false;
 974   }
 975 
 976   const pthread_t pthread_id = ::pthread_self();
 977   const tid_t kernel_thread_id = ::thread_self();
 978 
 979   // OSThread::thread_id is the pthread id.
 980   osthread->set_thread_id(pthread_id);
 981 
 982   // .. but keep kernel thread id too for diagnostics
 983   osthread->set_kernel_thread_id(kernel_thread_id);
 984 
 985   // initialize floating point control register
 986   os::Aix::init_thread_fpu_state();
 987 
 988   // Initial thread state is RUNNABLE
 989   osthread->set_state(RUNNABLE);
 990 
 991   thread->set_osthread(osthread);
 992 
 993   if (UseNUMA) {
 994     int lgrp_id = os::numa_get_group_id();
 995     if (lgrp_id != -1) {
 996       thread->set_lgrp_id(lgrp_id);
 997     }
 998   }
 999 
1000   // initialize signal mask for this thread
1001   // and save the caller's signal mask
1002   os::Aix::hotspot_sigmask(thread);
1003 
1004   log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", kernel thread id: " UINTX_FORMAT ").",
1005     os::current_thread_id(), (uintx) kernel_thread_id);
1006 
1007   return true;
1008 }
1009 
1010 void os::pd_start_thread(Thread* thread) {
1011   int status = pthread_continue_np(thread->osthread()->pthread_id());
1012   assert(status == 0, "thr_continue failed");
1013 }
1014 
1015 // Free OS resources related to the OSThread
1016 void os::free_thread(OSThread* osthread) {
1017   assert(osthread != NULL, "osthread not set");
1018 
1019   // We are told to free resources of the argument thread,
1020   // but we can only really operate on the current thread.
1021   assert(Thread::current()->osthread() == osthread,
1022          "os::free_thread but not current thread");
1023 
1024   // Restore caller's signal mask
1025   sigset_t sigmask = osthread->caller_sigmask();
1026   pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
1027 
1028   delete osthread;
1029 }
1030 
1031 ////////////////////////////////////////////////////////////////////////////////
1032 // time support
1033 
1034 // Time since start-up in seconds to a fine granularity.
1035 // Used by VMSelfDestructTimer and the MemProfiler.
1036 double os::elapsedTime() {
1037   return (double)(os::elapsed_counter()) * 0.000001;
1038 }
1039 
1040 jlong os::elapsed_counter() {
1041   timeval time;
1042   int status = gettimeofday(&time, NULL);
1043   return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count;
1044 }
1045 
1046 jlong os::elapsed_frequency() {
1047   return (1000 * 1000);
1048 }
1049 
1050 bool os::supports_vtime() { return true; }
1051 bool os::enable_vtime()   { return false; }
1052 bool os::vtime_enabled()  { return false; }
1053 
1054 double os::elapsedVTime() {
1055   struct rusage usage;
1056   int retval = getrusage(RUSAGE_THREAD, &usage);
1057   if (retval == 0) {
1058     return usage.ru_utime.tv_sec + usage.ru_stime.tv_sec + (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000.0 * 1000);
1059   } else {
1060     // better than nothing, but not much
1061     return elapsedTime();
1062   }
1063 }
1064 
1065 jlong os::javaTimeMillis() {
1066   timeval time;
1067   int status = gettimeofday(&time, NULL);
1068   assert(status != -1, "aix error at gettimeofday()");
1069   return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
1070 }
1071 
1072 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
1073   timeval time;
1074   int status = gettimeofday(&time, NULL);
1075   assert(status != -1, "aix error at gettimeofday()");
1076   seconds = jlong(time.tv_sec);
1077   nanos = jlong(time.tv_usec) * 1000;
1078 }
1079 
1080 // We use mread_real_time here.
1081 // On AIX: If the CPU has a time register, the result will be RTC_POWER and
1082 // it has to be converted to real time. AIX documentations suggests to do
1083 // this unconditionally, so we do it.
1084 //
1085 // See: https://www.ibm.com/support/knowledgecenter/ssw_aix_61/com.ibm.aix.basetrf2/read_real_time.htm
1086 //
1087 // On PASE: mread_real_time will always return RTC_POWER_PC data, so no
1088 // conversion is necessary. However, mread_real_time will not return
1089 // monotonic results but merely matches read_real_time. So we need a tweak
1090 // to ensure monotonic results.
1091 //
1092 // For PASE no public documentation exists, just word by IBM
1093 jlong os::javaTimeNanos() {
1094   timebasestruct_t time;
1095   int rc = mread_real_time(&time, TIMEBASE_SZ);
1096   if (os::Aix::on_pase()) {
1097     assert(rc == RTC_POWER, "expected time format RTC_POWER from mread_real_time in PASE");
1098     jlong now = jlong(time.tb_high) * NANOSECS_PER_SEC + jlong(time.tb_low);
1099     jlong prev = max_real_time;
1100     if (now <= prev) {
1101       return prev;   // same or retrograde time;
1102     }
1103     jlong obsv = Atomic::cmpxchg(now, &max_real_time, prev);
1104     assert(obsv >= prev, "invariant");   // Monotonicity
1105     // If the CAS succeeded then we're done and return "now".
1106     // If the CAS failed and the observed value "obsv" is >= now then
1107     // we should return "obsv".  If the CAS failed and now > obsv > prv then
1108     // some other thread raced this thread and installed a new value, in which case
1109     // we could either (a) retry the entire operation, (b) retry trying to install now
1110     // or (c) just return obsv.  We use (c).   No loop is required although in some cases
1111     // we might discard a higher "now" value in deference to a slightly lower but freshly
1112     // installed obsv value.   That's entirely benign -- it admits no new orderings compared
1113     // to (a) or (b) -- and greatly reduces coherence traffic.
1114     // We might also condition (c) on the magnitude of the delta between obsv and now.
1115     // Avoiding excessive CAS operations to hot RW locations is critical.
1116     // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1117     return (prev == obsv) ? now : obsv;
1118   } else {
1119     if (rc != RTC_POWER) {
1120       rc = time_base_to_time(&time, TIMEBASE_SZ);
1121       assert(rc != -1, "error calling time_base_to_time()");
1122     }
1123     return jlong(time.tb_high) * NANOSECS_PER_SEC + jlong(time.tb_low);
1124   }
1125 }
1126 
1127 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1128   info_ptr->max_value = ALL_64_BITS;
1129   // mread_real_time() is monotonic (see 'os::javaTimeNanos()')
1130   info_ptr->may_skip_backward = false;
1131   info_ptr->may_skip_forward = false;
1132   info_ptr->kind = JVMTI_TIMER_ELAPSED;    // elapsed not CPU time
1133 }
1134 
1135 // Return the real, user, and system times in seconds from an
1136 // arbitrary fixed point in the past.
1137 bool os::getTimesSecs(double* process_real_time,
1138                       double* process_user_time,
1139                       double* process_system_time) {
1140   struct tms ticks;
1141   clock_t real_ticks = times(&ticks);
1142 
1143   if (real_ticks == (clock_t) (-1)) {
1144     return false;
1145   } else {
1146     double ticks_per_second = (double) clock_tics_per_sec;
1147     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1148     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1149     *process_real_time = ((double) real_ticks) / ticks_per_second;
1150 
1151     return true;
1152   }
1153 }
1154 
1155 char * os::local_time_string(char *buf, size_t buflen) {
1156   struct tm t;
1157   time_t long_time;
1158   time(&long_time);
1159   localtime_r(&long_time, &t);
1160   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1161                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1162                t.tm_hour, t.tm_min, t.tm_sec);
1163   return buf;
1164 }
1165 
1166 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1167   return localtime_r(clock, res);
1168 }
1169 
1170 ////////////////////////////////////////////////////////////////////////////////
1171 // runtime exit support
1172 
1173 // Note: os::shutdown() might be called very early during initialization, or
1174 // called from signal handler. Before adding something to os::shutdown(), make
1175 // sure it is async-safe and can handle partially initialized VM.
1176 void os::shutdown() {
1177 
1178   // allow PerfMemory to attempt cleanup of any persistent resources
1179   perfMemory_exit();
1180 
1181   // needs to remove object in file system
1182   AttachListener::abort();
1183 
1184   // flush buffered output, finish log files
1185   ostream_abort();
1186 
1187   // Check for abort hook
1188   abort_hook_t abort_hook = Arguments::abort_hook();
1189   if (abort_hook != NULL) {
1190     abort_hook();
1191   }
1192 }
1193 
1194 // Note: os::abort() might be called very early during initialization, or
1195 // called from signal handler. Before adding something to os::abort(), make
1196 // sure it is async-safe and can handle partially initialized VM.
1197 void os::abort(bool dump_core, void* siginfo, const void* context) {
1198   os::shutdown();
1199   if (dump_core) {
1200 #ifndef PRODUCT
1201     fdStream out(defaultStream::output_fd());
1202     out.print_raw("Current thread is ");
1203     char buf[16];
1204     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1205     out.print_raw_cr(buf);
1206     out.print_raw_cr("Dumping core ...");
1207 #endif
1208     ::abort(); // dump core
1209   }
1210 
1211   ::exit(1);
1212 }
1213 
1214 // Die immediately, no exit hook, no abort hook, no cleanup.
1215 void os::die() {
1216   ::abort();
1217 }
1218 
1219 // This method is a copy of JDK's sysGetLastErrorString
1220 // from src/solaris/hpi/src/system_md.c
1221 
1222 size_t os::lasterror(char *buf, size_t len) {
1223   if (errno == 0) return 0;
1224 
1225   const char *s = os::strerror(errno);
1226   size_t n = ::strlen(s);
1227   if (n >= len) {
1228     n = len - 1;
1229   }
1230   ::strncpy(buf, s, n);
1231   buf[n] = '\0';
1232   return n;
1233 }
1234 
1235 intx os::current_thread_id() {
1236   return (intx)pthread_self();
1237 }
1238 
1239 int os::current_process_id() {
1240   return getpid();
1241 }
1242 
1243 // DLL functions
1244 
1245 const char* os::dll_file_extension() { return ".so"; }
1246 
1247 // This must be hard coded because it's the system's temporary
1248 // directory not the java application's temp directory, ala java.io.tmpdir.
1249 const char* os::get_temp_directory() { return "/tmp"; }
1250 
1251 // Check if addr is inside libjvm.so.
1252 bool os::address_is_in_vm(address addr) {
1253 
1254   // Input could be a real pc or a function pointer literal. The latter
1255   // would be a function descriptor residing in the data segment of a module.
1256   loaded_module_t lm;
1257   if (LoadedLibraries::find_for_text_address(addr, &lm) != NULL) {
1258     return lm.is_in_vm;
1259   } else if (LoadedLibraries::find_for_data_address(addr, &lm) != NULL) {
1260     return lm.is_in_vm;
1261   } else {
1262     return false;
1263   }
1264 
1265 }
1266 
1267 // Resolve an AIX function descriptor literal to a code pointer.
1268 // If the input is a valid code pointer to a text segment of a loaded module,
1269 //   it is returned unchanged.
1270 // If the input is a valid AIX function descriptor, it is resolved to the
1271 //   code entry point.
1272 // If the input is neither a valid function descriptor nor a valid code pointer,
1273 //   NULL is returned.
1274 static address resolve_function_descriptor_to_code_pointer(address p) {
1275 
1276   if (LoadedLibraries::find_for_text_address(p, NULL) != NULL) {
1277     // It is a real code pointer.
1278     return p;
1279   } else if (LoadedLibraries::find_for_data_address(p, NULL) != NULL) {
1280     // Pointer to data segment, potential function descriptor.
1281     address code_entry = (address)(((FunctionDescriptor*)p)->entry());
1282     if (LoadedLibraries::find_for_text_address(code_entry, NULL) != NULL) {
1283       // It is a function descriptor.
1284       return code_entry;
1285     }
1286   }
1287 
1288   return NULL;
1289 }
1290 
1291 bool os::dll_address_to_function_name(address addr, char *buf,
1292                                       int buflen, int *offset,
1293                                       bool demangle) {
1294   if (offset) {
1295     *offset = -1;
1296   }
1297   // Buf is not optional, but offset is optional.
1298   assert(buf != NULL, "sanity check");
1299   buf[0] = '\0';
1300 
1301   // Resolve function ptr literals first.
1302   addr = resolve_function_descriptor_to_code_pointer(addr);
1303   if (!addr) {
1304     return false;
1305   }
1306 
1307   return AixSymbols::get_function_name(addr, buf, buflen, offset, NULL, demangle);
1308 }
1309 
1310 bool os::dll_address_to_library_name(address addr, char* buf,
1311                                      int buflen, int* offset) {
1312   if (offset) {
1313     *offset = -1;
1314   }
1315   // Buf is not optional, but offset is optional.
1316   assert(buf != NULL, "sanity check");
1317   buf[0] = '\0';
1318 
1319   // Resolve function ptr literals first.
1320   addr = resolve_function_descriptor_to_code_pointer(addr);
1321   if (!addr) {
1322     return false;
1323   }
1324 
1325   return AixSymbols::get_module_name(addr, buf, buflen);
1326 }
1327 
1328 // Loads .dll/.so and in case of error it checks if .dll/.so was built
1329 // for the same architecture as Hotspot is running on.
1330 void *os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1331 
1332   if (ebuf && ebuflen > 0) {
1333     ebuf[0] = '\0';
1334     ebuf[ebuflen - 1] = '\0';
1335   }
1336 
1337   if (!filename || strlen(filename) == 0) {
1338     ::strncpy(ebuf, "dll_load: empty filename specified", ebuflen - 1);
1339     return NULL;
1340   }
1341 
1342   // RTLD_LAZY is currently not implemented. The dl is loaded immediately with all its dependants.
1343   void * result= ::dlopen(filename, RTLD_LAZY);
1344   if (result != NULL) {
1345     // Reload dll cache. Don't do this in signal handling.
1346     LoadedLibraries::reload();
1347     return result;
1348   } else {
1349     // error analysis when dlopen fails
1350     const char* const error_report = ::dlerror();
1351     if (error_report && ebuf && ebuflen > 0) {
1352       snprintf(ebuf, ebuflen - 1, "%s, LIBPATH=%s, LD_LIBRARY_PATH=%s : %s",
1353                filename, ::getenv("LIBPATH"), ::getenv("LD_LIBRARY_PATH"), error_report);
1354     }
1355   }
1356   return NULL;
1357 }
1358 
1359 void* os::dll_lookup(void* handle, const char* name) {
1360   void* res = dlsym(handle, name);
1361   return res;
1362 }
1363 
1364 void* os::get_default_process_handle() {
1365   return (void*)::dlopen(NULL, RTLD_LAZY);
1366 }
1367 
1368 void os::print_dll_info(outputStream *st) {
1369   st->print_cr("Dynamic libraries:");
1370   LoadedLibraries::print(st);
1371 }
1372 
1373 void os::get_summary_os_info(char* buf, size_t buflen) {
1374   // There might be something more readable than uname results for AIX.
1375   struct utsname name;
1376   uname(&name);
1377   snprintf(buf, buflen, "%s %s", name.release, name.version);
1378 }
1379 
1380 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1381   // Not yet implemented.
1382   return 0;
1383 }
1384 
1385 void os::print_os_info_brief(outputStream* st) {
1386   uint32_t ver = os::Aix::os_version();
1387   st->print_cr("AIX kernel version %u.%u.%u.%u",
1388                (ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
1389 
1390   os::Posix::print_uname_info(st);
1391 
1392   // Linux uses print_libversion_info(st); here.
1393 }
1394 
1395 void os::print_os_info(outputStream* st) {
1396   st->print("OS:");
1397 
1398   st->print("uname:");
1399   struct utsname name;
1400   uname(&name);
1401   st->print(name.sysname); st->print(" ");
1402   st->print(name.nodename); st->print(" ");
1403   st->print(name.release); st->print(" ");
1404   st->print(name.version); st->print(" ");
1405   st->print(name.machine);
1406   st->cr();
1407 
1408   uint32_t ver = os::Aix::os_version();
1409   st->print_cr("AIX kernel version %u.%u.%u.%u",
1410                (ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
1411 
1412   os::Posix::print_rlimit_info(st);
1413 
1414   // load average
1415   st->print("load average:");
1416   double loadavg[3] = {-1.L, -1.L, -1.L};
1417   os::loadavg(loadavg, 3);
1418   st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
1419   st->cr();
1420 
1421   // print wpar info
1422   libperfstat::wparinfo_t wi;
1423   if (libperfstat::get_wparinfo(&wi)) {
1424     st->print_cr("wpar info");
1425     st->print_cr("name: %s", wi.name);
1426     st->print_cr("id:   %d", wi.wpar_id);
1427     st->print_cr("type: %s", (wi.app_wpar ? "application" : "system"));
1428   }
1429 
1430   // print partition info
1431   libperfstat::partitioninfo_t pi;
1432   if (libperfstat::get_partitioninfo(&pi)) {
1433     st->print_cr("partition info");
1434     st->print_cr(" name: %s", pi.name);
1435   }
1436 
1437 }
1438 
1439 void os::print_memory_info(outputStream* st) {
1440 
1441   st->print_cr("Memory:");
1442 
1443   st->print_cr("  Base page size (sysconf _SC_PAGESIZE):  %s",
1444     describe_pagesize(g_multipage_support.pagesize));
1445   st->print_cr("  Data page size (C-Heap, bss, etc):      %s",
1446     describe_pagesize(g_multipage_support.datapsize));
1447   st->print_cr("  Text page size:                         %s",
1448     describe_pagesize(g_multipage_support.textpsize));
1449   st->print_cr("  Thread stack page size (pthread):       %s",
1450     describe_pagesize(g_multipage_support.pthr_stack_pagesize));
1451   st->print_cr("  Default shared memory page size:        %s",
1452     describe_pagesize(g_multipage_support.shmpsize));
1453   st->print_cr("  Can use 64K pages dynamically with shared meory:  %s",
1454     (g_multipage_support.can_use_64K_pages ? "yes" :"no"));
1455   st->print_cr("  Can use 16M pages dynamically with shared memory: %s",
1456     (g_multipage_support.can_use_16M_pages ? "yes" :"no"));
1457   st->print_cr("  Multipage error: %d",
1458     g_multipage_support.error);
1459   st->cr();
1460   st->print_cr("  os::vm_page_size:       %s", describe_pagesize(os::vm_page_size()));
1461 
1462   // print out LDR_CNTRL because it affects the default page sizes
1463   const char* const ldr_cntrl = ::getenv("LDR_CNTRL");
1464   st->print_cr("  LDR_CNTRL=%s.", ldr_cntrl ? ldr_cntrl : "<unset>");
1465 
1466   // Print out EXTSHM because it is an unsupported setting.
1467   const char* const extshm = ::getenv("EXTSHM");
1468   st->print_cr("  EXTSHM=%s.", extshm ? extshm : "<unset>");
1469   if ( (strcmp(extshm, "on") == 0) || (strcmp(extshm, "ON") == 0) ) {
1470     st->print_cr("  *** Unsupported! Please remove EXTSHM from your environment! ***");
1471   }
1472 
1473   // Print out AIXTHREAD_GUARDPAGES because it affects the size of pthread stacks.
1474   const char* const aixthread_guardpages = ::getenv("AIXTHREAD_GUARDPAGES");
1475   st->print_cr("  AIXTHREAD_GUARDPAGES=%s.",
1476       aixthread_guardpages ? aixthread_guardpages : "<unset>");
1477   st->cr();
1478 
1479   os::Aix::meminfo_t mi;
1480   if (os::Aix::get_meminfo(&mi)) {
1481     if (os::Aix::on_aix()) {
1482       st->print_cr("physical total : " SIZE_FORMAT, mi.real_total);
1483       st->print_cr("physical free  : " SIZE_FORMAT, mi.real_free);
1484       st->print_cr("swap total     : " SIZE_FORMAT, mi.pgsp_total);
1485       st->print_cr("swap free      : " SIZE_FORMAT, mi.pgsp_free);
1486     } else {
1487       // PASE - Numbers are result of QWCRSSTS; they mean:
1488       // real_total: Sum of all system pools
1489       // real_free: always 0
1490       // pgsp_total: we take the size of the system ASP
1491       // pgsp_free: size of system ASP times percentage of system ASP unused
1492       st->print_cr("physical total     : " SIZE_FORMAT, mi.real_total);
1493       st->print_cr("system asp total   : " SIZE_FORMAT, mi.pgsp_total);
1494       st->print_cr("%% system asp used : %.2f",
1495         mi.pgsp_total ? (100.0f * (mi.pgsp_total - mi.pgsp_free) / mi.pgsp_total) : -1.0f);
1496     }
1497   }
1498   st->cr();
1499 
1500   // Print program break.
1501   st->print_cr("Program break at VM startup: " PTR_FORMAT ".", p2i(g_brk_at_startup));
1502   address brk_now = (address)::sbrk(0);
1503   if (brk_now != (address)-1) {
1504     st->print_cr("Program break now          : " PTR_FORMAT " (distance: " SIZE_FORMAT "k).",
1505                  p2i(brk_now), (size_t)((brk_now - g_brk_at_startup) / K));
1506   }
1507   st->print_cr("MaxExpectedDataSegmentSize    : " SIZE_FORMAT "k.", MaxExpectedDataSegmentSize / K);
1508   st->cr();
1509 
1510   // Print segments allocated with os::reserve_memory.
1511   st->print_cr("internal virtual memory regions used by vm:");
1512   vmembk_print_on(st);
1513 }
1514 
1515 // Get a string for the cpuinfo that is a summary of the cpu type
1516 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1517   // read _system_configuration.version
1518   switch (_system_configuration.version) {
1519   case PV_8:
1520     strncpy(buf, "Power PC 8", buflen);
1521     break;
1522   case PV_7:
1523     strncpy(buf, "Power PC 7", buflen);
1524     break;
1525   case PV_6_1:
1526     strncpy(buf, "Power PC 6 DD1.x", buflen);
1527     break;
1528   case PV_6:
1529     strncpy(buf, "Power PC 6", buflen);
1530     break;
1531   case PV_5:
1532     strncpy(buf, "Power PC 5", buflen);
1533     break;
1534   case PV_5_2:
1535     strncpy(buf, "Power PC 5_2", buflen);
1536     break;
1537   case PV_5_3:
1538     strncpy(buf, "Power PC 5_3", buflen);
1539     break;
1540   case PV_5_Compat:
1541     strncpy(buf, "PV_5_Compat", buflen);
1542     break;
1543   case PV_6_Compat:
1544     strncpy(buf, "PV_6_Compat", buflen);
1545     break;
1546   case PV_7_Compat:
1547     strncpy(buf, "PV_7_Compat", buflen);
1548     break;
1549   case PV_8_Compat:
1550     strncpy(buf, "PV_8_Compat", buflen);
1551     break;
1552   default:
1553     strncpy(buf, "unknown", buflen);
1554   }
1555 }
1556 
1557 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1558   // Nothing to do beyond of what os::print_cpu_info() does.
1559 }
1560 
1561 static void print_signal_handler(outputStream* st, int sig,
1562                                  char* buf, size_t buflen);
1563 
1564 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1565   st->print_cr("Signal Handlers:");
1566   print_signal_handler(st, SIGSEGV, buf, buflen);
1567   print_signal_handler(st, SIGBUS , buf, buflen);
1568   print_signal_handler(st, SIGFPE , buf, buflen);
1569   print_signal_handler(st, SIGPIPE, buf, buflen);
1570   print_signal_handler(st, SIGXFSZ, buf, buflen);
1571   print_signal_handler(st, SIGILL , buf, buflen);
1572   print_signal_handler(st, SR_signum, buf, buflen);
1573   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1574   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1575   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1576   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1577   print_signal_handler(st, SIGTRAP, buf, buflen);
1578   // We also want to know if someone else adds a SIGDANGER handler because
1579   // that will interfere with OOM killling.
1580   print_signal_handler(st, SIGDANGER, buf, buflen);
1581 }
1582 
1583 static char saved_jvm_path[MAXPATHLEN] = {0};
1584 
1585 // Find the full path to the current module, libjvm.so.
1586 void os::jvm_path(char *buf, jint buflen) {
1587   // Error checking.
1588   if (buflen < MAXPATHLEN) {
1589     assert(false, "must use a large-enough buffer");
1590     buf[0] = '\0';
1591     return;
1592   }
1593   // Lazy resolve the path to current module.
1594   if (saved_jvm_path[0] != 0) {
1595     strcpy(buf, saved_jvm_path);
1596     return;
1597   }
1598 
1599   Dl_info dlinfo;
1600   int ret = dladdr(CAST_FROM_FN_PTR(void *, os::jvm_path), &dlinfo);
1601   assert(ret != 0, "cannot locate libjvm");
1602   char* rp = os::Posix::realpath((char *)dlinfo.dli_fname, buf, buflen);
1603   assert(rp != NULL, "error in realpath(): maybe the 'path' argument is too long?");
1604 
1605   if (Arguments::sun_java_launcher_is_altjvm()) {
1606     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1607     // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
1608     // If "/jre/lib/" appears at the right place in the string, then
1609     // assume we are installed in a JDK and we're done. Otherwise, check
1610     // for a JAVA_HOME environment variable and fix up the path so it
1611     // looks like libjvm.so is installed there (append a fake suffix
1612     // hotspot/libjvm.so).
1613     const char *p = buf + strlen(buf) - 1;
1614     for (int count = 0; p > buf && count < 4; ++count) {
1615       for (--p; p > buf && *p != '/'; --p)
1616         /* empty */ ;
1617     }
1618 
1619     if (strncmp(p, "/jre/lib/", 9) != 0) {
1620       // Look for JAVA_HOME in the environment.
1621       char* java_home_var = ::getenv("JAVA_HOME");
1622       if (java_home_var != NULL && java_home_var[0] != 0) {
1623         char* jrelib_p;
1624         int len;
1625 
1626         // Check the current module name "libjvm.so".
1627         p = strrchr(buf, '/');
1628         if (p == NULL) {
1629           return;
1630         }
1631         assert(strstr(p, "/libjvm") == p, "invalid library name");
1632 
1633         rp = os::Posix::realpath(java_home_var, buf, buflen);
1634         if (rp == NULL) {
1635           return;
1636         }
1637 
1638         // determine if this is a legacy image or modules image
1639         // modules image doesn't have "jre" subdirectory
1640         len = strlen(buf);
1641         assert(len < buflen, "Ran out of buffer room");
1642         jrelib_p = buf + len;
1643         snprintf(jrelib_p, buflen-len, "/jre/lib");
1644         if (0 != access(buf, F_OK)) {
1645           snprintf(jrelib_p, buflen-len, "/lib");
1646         }
1647 
1648         if (0 == access(buf, F_OK)) {
1649           // Use current module name "libjvm.so"
1650           len = strlen(buf);
1651           snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
1652         } else {
1653           // Go back to path of .so
1654           rp = os::Posix::realpath((char *)dlinfo.dli_fname, buf, buflen);
1655           if (rp == NULL) {
1656             return;
1657           }
1658         }
1659       }
1660     }
1661   }
1662 
1663   strncpy(saved_jvm_path, buf, sizeof(saved_jvm_path));
1664   saved_jvm_path[sizeof(saved_jvm_path) - 1] = '\0';
1665 }
1666 
1667 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1668   // no prefix required, not even "_"
1669 }
1670 
1671 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1672   // no suffix required
1673 }
1674 
1675 ////////////////////////////////////////////////////////////////////////////////
1676 // sun.misc.Signal support
1677 
1678 static volatile jint sigint_count = 0;
1679 
1680 static void
1681 UserHandler(int sig, void *siginfo, void *context) {
1682   // 4511530 - sem_post is serialized and handled by the manager thread. When
1683   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1684   // don't want to flood the manager thread with sem_post requests.
1685   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
1686     return;
1687 
1688   // Ctrl-C is pressed during error reporting, likely because the error
1689   // handler fails to abort. Let VM die immediately.
1690   if (sig == SIGINT && VMError::is_error_reported()) {
1691     os::die();
1692   }
1693 
1694   os::signal_notify(sig);
1695 }
1696 
1697 void* os::user_handler() {
1698   return CAST_FROM_FN_PTR(void*, UserHandler);
1699 }
1700 
1701 extern "C" {
1702   typedef void (*sa_handler_t)(int);
1703   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1704 }
1705 
1706 void* os::signal(int signal_number, void* handler) {
1707   struct sigaction sigAct, oldSigAct;
1708 
1709   sigfillset(&(sigAct.sa_mask));
1710 
1711   // Do not block out synchronous signals in the signal handler.
1712   // Blocking synchronous signals only makes sense if you can really
1713   // be sure that those signals won't happen during signal handling,
1714   // when the blocking applies. Normal signal handlers are lean and
1715   // do not cause signals. But our signal handlers tend to be "risky"
1716   // - secondary SIGSEGV, SIGILL, SIGBUS' may and do happen.
1717   // On AIX, PASE there was a case where a SIGSEGV happened, followed
1718   // by a SIGILL, which was blocked due to the signal mask. The process
1719   // just hung forever. Better to crash from a secondary signal than to hang.
1720   sigdelset(&(sigAct.sa_mask), SIGSEGV);
1721   sigdelset(&(sigAct.sa_mask), SIGBUS);
1722   sigdelset(&(sigAct.sa_mask), SIGILL);
1723   sigdelset(&(sigAct.sa_mask), SIGFPE);
1724   sigdelset(&(sigAct.sa_mask), SIGTRAP);
1725 
1726   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1727 
1728   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1729 
1730   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1731     // -1 means registration failed
1732     return (void *)-1;
1733   }
1734 
1735   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1736 }
1737 
1738 void os::signal_raise(int signal_number) {
1739   ::raise(signal_number);
1740 }
1741 
1742 //
1743 // The following code is moved from os.cpp for making this
1744 // code platform specific, which it is by its very nature.
1745 //
1746 
1747 // Will be modified when max signal is changed to be dynamic
1748 int os::sigexitnum_pd() {
1749   return NSIG;
1750 }
1751 
1752 // a counter for each possible signal value
1753 static volatile jint pending_signals[NSIG+1] = { 0 };
1754 
1755 // Wrapper functions for: sem_init(), sem_post(), sem_wait()
1756 // On AIX, we use sem_init(), sem_post(), sem_wait()
1757 // On Pase, we need to use msem_lock() and msem_unlock(), because Posix Semaphores
1758 // do not seem to work at all on PASE (unimplemented, will cause SIGILL).
1759 // Note that just using msem_.. APIs for both PASE and AIX is not an option either, as
1760 // on AIX, msem_..() calls are suspected of causing problems.
1761 static sem_t sig_sem;
1762 static msemaphore* p_sig_msem = 0;
1763 
1764 static void local_sem_init() {
1765   if (os::Aix::on_aix()) {
1766     int rc = ::sem_init(&sig_sem, 0, 0);
1767     guarantee(rc != -1, "sem_init failed");
1768   } else {
1769     // Memory semaphores must live in shared mem.
1770     guarantee0(p_sig_msem == NULL);
1771     p_sig_msem = (msemaphore*)os::reserve_memory(sizeof(msemaphore), NULL);
1772     guarantee(p_sig_msem, "Cannot allocate memory for memory semaphore");
1773     guarantee(::msem_init(p_sig_msem, 0) == p_sig_msem, "msem_init failed");
1774   }
1775 }
1776 
1777 static void local_sem_post() {
1778   static bool warn_only_once = false;
1779   if (os::Aix::on_aix()) {
1780     int rc = ::sem_post(&sig_sem);
1781     if (rc == -1 && !warn_only_once) {
1782       trcVerbose("sem_post failed (errno = %d, %s)", errno, os::errno_name(errno));
1783       warn_only_once = true;
1784     }
1785   } else {
1786     guarantee0(p_sig_msem != NULL);
1787     int rc = ::msem_unlock(p_sig_msem, 0);
1788     if (rc == -1 && !warn_only_once) {
1789       trcVerbose("msem_unlock failed (errno = %d, %s)", errno, os::errno_name(errno));
1790       warn_only_once = true;
1791     }
1792   }
1793 }
1794 
1795 static void local_sem_wait() {
1796   static bool warn_only_once = false;
1797   if (os::Aix::on_aix()) {
1798     int rc = ::sem_wait(&sig_sem);
1799     if (rc == -1 && !warn_only_once) {
1800       trcVerbose("sem_wait failed (errno = %d, %s)", errno, os::errno_name(errno));
1801       warn_only_once = true;
1802     }
1803   } else {
1804     guarantee0(p_sig_msem != NULL); // must init before use
1805     int rc = ::msem_lock(p_sig_msem, 0);
1806     if (rc == -1 && !warn_only_once) {
1807       trcVerbose("msem_lock failed (errno = %d, %s)", errno, os::errno_name(errno));
1808       warn_only_once = true;
1809     }
1810   }
1811 }
1812 
1813 static void jdk_misc_signal_init() {
1814   // Initialize signal structures
1815   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1816 
1817   // Initialize signal semaphore
1818   local_sem_init();
1819 }
1820 
1821 void os::signal_notify(int sig) {
1822   Atomic::inc(&pending_signals[sig]);
1823   local_sem_post();
1824 }
1825 
1826 static int check_pending_signals() {
1827   Atomic::store(0, &sigint_count);
1828   for (;;) {
1829     for (int i = 0; i < NSIG + 1; i++) {
1830       jint n = pending_signals[i];
1831       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1832         return i;
1833       }
1834     }
1835     JavaThread *thread = JavaThread::current();
1836     ThreadBlockInVM tbivm(thread);
1837 
1838     bool threadIsSuspended;
1839     do {
1840       thread->set_suspend_equivalent();
1841       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1842 
1843       local_sem_wait();
1844 
1845       // were we externally suspended while we were waiting?
1846       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1847       if (threadIsSuspended) {
1848         //
1849         // The semaphore has been incremented, but while we were waiting
1850         // another thread suspended us. We don't want to continue running
1851         // while suspended because that would surprise the thread that
1852         // suspended us.
1853         //
1854 
1855         local_sem_post();
1856 
1857         thread->java_suspend_self();
1858       }
1859     } while (threadIsSuspended);
1860   }
1861 }
1862 
1863 int os::signal_wait() {
1864   return check_pending_signals();
1865 }
1866 
1867 ////////////////////////////////////////////////////////////////////////////////
1868 // Virtual Memory
1869 
1870 // We need to keep small simple bookkeeping for os::reserve_memory and friends.
1871 
1872 #define VMEM_MAPPED  1
1873 #define VMEM_SHMATED 2
1874 
1875 struct vmembk_t {
1876   int type;         // 1 - mmap, 2 - shmat
1877   char* addr;
1878   size_t size;      // Real size, may be larger than usersize.
1879   size_t pagesize;  // page size of area
1880   vmembk_t* next;
1881 
1882   bool contains_addr(char* p) const {
1883     return p >= addr && p < (addr + size);
1884   }
1885 
1886   bool contains_range(char* p, size_t s) const {
1887     return contains_addr(p) && contains_addr(p + s - 1);
1888   }
1889 
1890   void print_on(outputStream* os) const {
1891     os->print("[" PTR_FORMAT " - " PTR_FORMAT "] (" UINTX_FORMAT
1892       " bytes, %d %s pages), %s",
1893       addr, addr + size - 1, size, size / pagesize, describe_pagesize(pagesize),
1894       (type == VMEM_SHMATED ? "shmat" : "mmap")
1895     );
1896   }
1897 
1898   // Check that range is a sub range of memory block (or equal to memory block);
1899   // also check that range is fully page aligned to the page size if the block.
1900   void assert_is_valid_subrange(char* p, size_t s) const {
1901     if (!contains_range(p, s)) {
1902       trcVerbose("[" PTR_FORMAT " - " PTR_FORMAT "] is not a sub "
1903               "range of [" PTR_FORMAT " - " PTR_FORMAT "].",
1904               p, p + s, addr, addr + size);
1905       guarantee0(false);
1906     }
1907     if (!is_aligned_to(p, pagesize) || !is_aligned_to(p + s, pagesize)) {
1908       trcVerbose("range [" PTR_FORMAT " - " PTR_FORMAT "] is not"
1909               " aligned to pagesize (%lu)", p, p + s, (unsigned long) pagesize);
1910       guarantee0(false);
1911     }
1912   }
1913 };
1914 
1915 static struct {
1916   vmembk_t* first;
1917   MiscUtils::CritSect cs;
1918 } vmem;
1919 
1920 static void vmembk_add(char* addr, size_t size, size_t pagesize, int type) {
1921   vmembk_t* p = (vmembk_t*) ::malloc(sizeof(vmembk_t));
1922   assert0(p);
1923   if (p) {
1924     MiscUtils::AutoCritSect lck(&vmem.cs);
1925     p->addr = addr; p->size = size;
1926     p->pagesize = pagesize;
1927     p->type = type;
1928     p->next = vmem.first;
1929     vmem.first = p;
1930   }
1931 }
1932 
1933 static vmembk_t* vmembk_find(char* addr) {
1934   MiscUtils::AutoCritSect lck(&vmem.cs);
1935   for (vmembk_t* p = vmem.first; p; p = p->next) {
1936     if (p->addr <= addr && (p->addr + p->size) > addr) {
1937       return p;
1938     }
1939   }
1940   return NULL;
1941 }
1942 
1943 static void vmembk_remove(vmembk_t* p0) {
1944   MiscUtils::AutoCritSect lck(&vmem.cs);
1945   assert0(p0);
1946   assert0(vmem.first); // List should not be empty.
1947   for (vmembk_t** pp = &(vmem.first); *pp; pp = &((*pp)->next)) {
1948     if (*pp == p0) {
1949       *pp = p0->next;
1950       ::free(p0);
1951       return;
1952     }
1953   }
1954   assert0(false); // Not found?
1955 }
1956 
1957 static void vmembk_print_on(outputStream* os) {
1958   MiscUtils::AutoCritSect lck(&vmem.cs);
1959   for (vmembk_t* vmi = vmem.first; vmi; vmi = vmi->next) {
1960     vmi->print_on(os);
1961     os->cr();
1962   }
1963 }
1964 
1965 // Reserve and attach a section of System V memory.
1966 // If <requested_addr> is not NULL, function will attempt to attach the memory at the given
1967 // address. Failing that, it will attach the memory anywhere.
1968 // If <requested_addr> is NULL, function will attach the memory anywhere.
1969 //
1970 // <alignment_hint> is being ignored by this function. It is very probable however that the
1971 // alignment requirements are met anyway, because shmat() attaches at 256M boundaries.
1972 // Should this be not enogh, we can put more work into it.
1973 static char* reserve_shmated_memory (
1974   size_t bytes,
1975   char* requested_addr,
1976   size_t alignment_hint) {
1977 
1978   trcVerbose("reserve_shmated_memory " UINTX_FORMAT " bytes, wishaddress "
1979     PTR_FORMAT ", alignment_hint " UINTX_FORMAT "...",
1980     bytes, requested_addr, alignment_hint);
1981 
1982   // Either give me wish address or wish alignment but not both.
1983   assert0(!(requested_addr != NULL && alignment_hint != 0));
1984 
1985   // We must prevent anyone from attaching too close to the
1986   // BRK because that may cause malloc OOM.
1987   if (requested_addr != NULL && is_close_to_brk((address)requested_addr)) {
1988     trcVerbose("Wish address " PTR_FORMAT " is too close to the BRK segment. "
1989       "Will attach anywhere.", requested_addr);
1990     // Act like the OS refused to attach there.
1991     requested_addr = NULL;
1992   }
1993 
1994   // For old AS/400's (V5R4 and older) we should not even be here - System V shared memory is not
1995   // really supported (max size 4GB), so reserve_mmapped_memory should have been used instead.
1996   if (os::Aix::on_pase_V5R4_or_older()) {
1997     ShouldNotReachHere();
1998   }
1999 
2000   // Align size of shm up to 64K to avoid errors if we later try to change the page size.
2001   const size_t size = align_up(bytes, 64*K);
2002 
2003   // Reserve the shared segment.
2004   int shmid = shmget(IPC_PRIVATE, size, IPC_CREAT | S_IRUSR | S_IWUSR);
2005   if (shmid == -1) {
2006     trcVerbose("shmget(.., " UINTX_FORMAT ", ..) failed (errno: %d).", size, errno);
2007     return NULL;
2008   }
2009 
2010   // Important note:
2011   // It is very important that we, upon leaving this function, do not leave a shm segment alive.
2012   // We must right after attaching it remove it from the system. System V shm segments are global and
2013   // survive the process.
2014   // So, from here on: Do not assert, do not return, until we have called shmctl(IPC_RMID) (A).
2015 
2016   struct shmid_ds shmbuf;
2017   memset(&shmbuf, 0, sizeof(shmbuf));
2018   shmbuf.shm_pagesize = 64*K;
2019   if (shmctl(shmid, SHM_PAGESIZE, &shmbuf) != 0) {
2020     trcVerbose("Failed to set page size (need " UINTX_FORMAT " 64K pages) - shmctl failed with %d.",
2021                size / (64*K), errno);
2022     // I want to know if this ever happens.
2023     assert(false, "failed to set page size for shmat");
2024   }
2025 
2026   // Now attach the shared segment.
2027   // Note that I attach with SHM_RND - which means that the requested address is rounded down, if
2028   // needed, to the next lowest segment boundary. Otherwise the attach would fail if the address
2029   // were not a segment boundary.
2030   char* const addr = (char*) shmat(shmid, requested_addr, SHM_RND);
2031   const int errno_shmat = errno;
2032 
2033   // (A) Right after shmat and before handing shmat errors delete the shm segment.
2034   if (::shmctl(shmid, IPC_RMID, NULL) == -1) {
2035     trcVerbose("shmctl(%u, IPC_RMID) failed (%d)\n", shmid, errno);
2036     assert(false, "failed to remove shared memory segment!");
2037   }
2038 
2039   // Handle shmat error. If we failed to attach, just return.
2040   if (addr == (char*)-1) {
2041     trcVerbose("Failed to attach segment at " PTR_FORMAT " (%d).", requested_addr, errno_shmat);
2042     return NULL;
2043   }
2044 
2045   // Just for info: query the real page size. In case setting the page size did not
2046   // work (see above), the system may have given us something other then 4K (LDR_CNTRL).
2047   const size_t real_pagesize = os::Aix::query_pagesize(addr);
2048   if (real_pagesize != shmbuf.shm_pagesize) {
2049     trcVerbose("pagesize is, surprisingly, %h.", real_pagesize);
2050   }
2051 
2052   if (addr) {
2053     trcVerbose("shm-allocated " PTR_FORMAT " .. " PTR_FORMAT " (" UINTX_FORMAT " bytes, " UINTX_FORMAT " %s pages)",
2054       addr, addr + size - 1, size, size/real_pagesize, describe_pagesize(real_pagesize));
2055   } else {
2056     if (requested_addr != NULL) {
2057       trcVerbose("failed to shm-allocate " UINTX_FORMAT " bytes at with address " PTR_FORMAT ".", size, requested_addr);
2058     } else {
2059       trcVerbose("failed to shm-allocate " UINTX_FORMAT " bytes at any address.", size);
2060     }
2061   }
2062 
2063   // book-keeping
2064   vmembk_add(addr, size, real_pagesize, VMEM_SHMATED);
2065   assert0(is_aligned_to(addr, os::vm_page_size()));
2066 
2067   return addr;
2068 }
2069 
2070 static bool release_shmated_memory(char* addr, size_t size) {
2071 
2072   trcVerbose("release_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2073     addr, addr + size - 1);
2074 
2075   bool rc = false;
2076 
2077   // TODO: is there a way to verify shm size without doing bookkeeping?
2078   if (::shmdt(addr) != 0) {
2079     trcVerbose("error (%d).", errno);
2080   } else {
2081     trcVerbose("ok.");
2082     rc = true;
2083   }
2084   return rc;
2085 }
2086 
2087 static bool uncommit_shmated_memory(char* addr, size_t size) {
2088   trcVerbose("uncommit_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2089     addr, addr + size - 1);
2090 
2091   const bool rc = my_disclaim64(addr, size);
2092 
2093   if (!rc) {
2094     trcVerbose("my_disclaim64(" PTR_FORMAT ", " UINTX_FORMAT ") failed.\n", addr, size);
2095     return false;
2096   }
2097   return true;
2098 }
2099 
2100 ////////////////////////////////  mmap-based routines /////////////////////////////////
2101 
2102 // Reserve memory via mmap.
2103 // If <requested_addr> is given, an attempt is made to attach at the given address.
2104 // Failing that, memory is allocated at any address.
2105 // If <alignment_hint> is given and <requested_addr> is NULL, an attempt is made to
2106 // allocate at an address aligned with the given alignment. Failing that, memory
2107 // is aligned anywhere.
2108 static char* reserve_mmaped_memory(size_t bytes, char* requested_addr, size_t alignment_hint) {
2109   trcVerbose("reserve_mmaped_memory " UINTX_FORMAT " bytes, wishaddress " PTR_FORMAT ", "
2110     "alignment_hint " UINTX_FORMAT "...",
2111     bytes, requested_addr, alignment_hint);
2112 
2113   // If a wish address is given, but not aligned to 4K page boundary, mmap will fail.
2114   if (requested_addr && !is_aligned_to(requested_addr, os::vm_page_size()) != 0) {
2115     trcVerbose("Wish address " PTR_FORMAT " not aligned to page boundary.", requested_addr);
2116     return NULL;
2117   }
2118 
2119   // We must prevent anyone from attaching too close to the
2120   // BRK because that may cause malloc OOM.
2121   if (requested_addr != NULL && is_close_to_brk((address)requested_addr)) {
2122     trcVerbose("Wish address " PTR_FORMAT " is too close to the BRK segment. "
2123       "Will attach anywhere.", requested_addr);
2124     // Act like the OS refused to attach there.
2125     requested_addr = NULL;
2126   }
2127 
2128   // Specify one or the other but not both.
2129   assert0(!(requested_addr != NULL && alignment_hint > 0));
2130 
2131   // In 64K mode, we claim the global page size (os::vm_page_size())
2132   // is 64K. This is one of the few points where that illusion may
2133   // break, because mmap() will always return memory aligned to 4K. So
2134   // we must ensure we only ever return memory aligned to 64k.
2135   if (alignment_hint) {
2136     alignment_hint = lcm(alignment_hint, os::vm_page_size());
2137   } else {
2138     alignment_hint = os::vm_page_size();
2139   }
2140 
2141   // Size shall always be a multiple of os::vm_page_size (esp. in 64K mode).
2142   const size_t size = align_up(bytes, os::vm_page_size());
2143 
2144   // alignment: Allocate memory large enough to include an aligned range of the right size and
2145   // cut off the leading and trailing waste pages.
2146   assert0(alignment_hint != 0 && is_aligned_to(alignment_hint, os::vm_page_size())); // see above
2147   const size_t extra_size = size + alignment_hint;
2148 
2149   // Note: MAP_SHARED (instead of MAP_PRIVATE) needed to be able to
2150   // later use msync(MS_INVALIDATE) (see os::uncommit_memory).
2151   int flags = MAP_ANONYMOUS | MAP_SHARED;
2152 
2153   // MAP_FIXED is needed to enforce requested_addr - manpage is vague about what
2154   // it means if wishaddress is given but MAP_FIXED is not set.
2155   //
2156   // Important! Behaviour differs depending on whether SPEC1170 mode is active or not.
2157   // SPEC1170 mode active: behaviour like POSIX, MAP_FIXED will clobber existing mappings.
2158   // SPEC1170 mode not active: behaviour, unlike POSIX, is that no existing mappings will
2159   // get clobbered.
2160   if (requested_addr != NULL) {
2161     if (!os::Aix::xpg_sus_mode()) {  // not SPEC1170 Behaviour
2162       flags |= MAP_FIXED;
2163     }
2164   }
2165 
2166   char* addr = (char*)::mmap(requested_addr, extra_size,
2167       PROT_READ|PROT_WRITE|PROT_EXEC, flags, -1, 0);
2168 
2169   if (addr == MAP_FAILED) {
2170     trcVerbose("mmap(" PTR_FORMAT ", " UINTX_FORMAT ", ..) failed (%d)", requested_addr, size, errno);
2171     return NULL;
2172   }
2173 
2174   // Handle alignment.
2175   char* const addr_aligned = align_up(addr, alignment_hint);
2176   const size_t waste_pre = addr_aligned - addr;
2177   char* const addr_aligned_end = addr_aligned + size;
2178   const size_t waste_post = extra_size - waste_pre - size;
2179   if (waste_pre > 0) {
2180     ::munmap(addr, waste_pre);
2181   }
2182   if (waste_post > 0) {
2183     ::munmap(addr_aligned_end, waste_post);
2184   }
2185   addr = addr_aligned;
2186 
2187   if (addr) {
2188     trcVerbose("mmap-allocated " PTR_FORMAT " .. " PTR_FORMAT " (" UINTX_FORMAT " bytes)",
2189       addr, addr + bytes, bytes);
2190   } else {
2191     if (requested_addr != NULL) {
2192       trcVerbose("failed to mmap-allocate " UINTX_FORMAT " bytes at wish address " PTR_FORMAT ".", bytes, requested_addr);
2193     } else {
2194       trcVerbose("failed to mmap-allocate " UINTX_FORMAT " bytes at any address.", bytes);
2195     }
2196   }
2197 
2198   // bookkeeping
2199   vmembk_add(addr, size, 4*K, VMEM_MAPPED);
2200 
2201   // Test alignment, see above.
2202   assert0(is_aligned_to(addr, os::vm_page_size()));
2203 
2204   return addr;
2205 }
2206 
2207 static bool release_mmaped_memory(char* addr, size_t size) {
2208   assert0(is_aligned_to(addr, os::vm_page_size()));
2209   assert0(is_aligned_to(size, os::vm_page_size()));
2210 
2211   trcVerbose("release_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2212     addr, addr + size - 1);
2213   bool rc = false;
2214 
2215   if (::munmap(addr, size) != 0) {
2216     trcVerbose("failed (%d)\n", errno);
2217     rc = false;
2218   } else {
2219     trcVerbose("ok.");
2220     rc = true;
2221   }
2222 
2223   return rc;
2224 }
2225 
2226 static bool uncommit_mmaped_memory(char* addr, size_t size) {
2227 
2228   assert0(is_aligned_to(addr, os::vm_page_size()));
2229   assert0(is_aligned_to(size, os::vm_page_size()));
2230 
2231   trcVerbose("uncommit_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2232     addr, addr + size - 1);
2233   bool rc = false;
2234 
2235   // Uncommit mmap memory with msync MS_INVALIDATE.
2236   if (::msync(addr, size, MS_INVALIDATE) != 0) {
2237     trcVerbose("failed (%d)\n", errno);
2238     rc = false;
2239   } else {
2240     trcVerbose("ok.");
2241     rc = true;
2242   }
2243 
2244   return rc;
2245 }
2246 
2247 int os::vm_page_size() {
2248   // Seems redundant as all get out.
2249   assert(os::Aix::page_size() != -1, "must call os::init");
2250   return os::Aix::page_size();
2251 }
2252 
2253 // Aix allocates memory by pages.
2254 int os::vm_allocation_granularity() {
2255   assert(os::Aix::page_size() != -1, "must call os::init");
2256   return os::Aix::page_size();
2257 }
2258 
2259 #ifdef PRODUCT
2260 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2261                                     int err) {
2262   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2263           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2264           os::errno_name(err), err);
2265 }
2266 #endif
2267 
2268 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2269                                   const char* mesg) {
2270   assert(mesg != NULL, "mesg must be specified");
2271   if (!pd_commit_memory(addr, size, exec)) {
2272     // Add extra info in product mode for vm_exit_out_of_memory():
2273     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2274     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2275   }
2276 }
2277 
2278 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2279 
2280   assert(is_aligned_to(addr, os::vm_page_size()),
2281     "addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2282     p2i(addr), os::vm_page_size());
2283   assert(is_aligned_to(size, os::vm_page_size()),
2284     "size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2285     size, os::vm_page_size());
2286 
2287   vmembk_t* const vmi = vmembk_find(addr);
2288   guarantee0(vmi);
2289   vmi->assert_is_valid_subrange(addr, size);
2290 
2291   trcVerbose("commit_memory [" PTR_FORMAT " - " PTR_FORMAT "].", addr, addr + size - 1);
2292 
2293   if (UseExplicitCommit) {
2294     // AIX commits memory on touch. So, touch all pages to be committed.
2295     for (char* p = addr; p < (addr + size); p += 4*K) {
2296       *p = '\0';
2297     }
2298   }
2299 
2300   return true;
2301 }
2302 
2303 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, bool exec) {
2304   return pd_commit_memory(addr, size, exec);
2305 }
2306 
2307 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2308                                   size_t alignment_hint, bool exec,
2309                                   const char* mesg) {
2310   // Alignment_hint is ignored on this OS.
2311   pd_commit_memory_or_exit(addr, size, exec, mesg);
2312 }
2313 
2314 bool os::pd_uncommit_memory(char* addr, size_t size) {
2315   assert(is_aligned_to(addr, os::vm_page_size()),
2316     "addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2317     p2i(addr), os::vm_page_size());
2318   assert(is_aligned_to(size, os::vm_page_size()),
2319     "size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2320     size, os::vm_page_size());
2321 
2322   // Dynamically do different things for mmap/shmat.
2323   const vmembk_t* const vmi = vmembk_find(addr);
2324   guarantee0(vmi);
2325   vmi->assert_is_valid_subrange(addr, size);
2326 
2327   if (vmi->type == VMEM_SHMATED) {
2328     return uncommit_shmated_memory(addr, size);
2329   } else {
2330     return uncommit_mmaped_memory(addr, size);
2331   }
2332 }
2333 
2334 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2335   // Do not call this; no need to commit stack pages on AIX.
2336   ShouldNotReachHere();
2337   return true;
2338 }
2339 
2340 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2341   // Do not call this; no need to commit stack pages on AIX.
2342   ShouldNotReachHere();
2343   return true;
2344 }
2345 
2346 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2347 }
2348 
2349 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2350 }
2351 
2352 void os::numa_make_global(char *addr, size_t bytes) {
2353 }
2354 
2355 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2356 }
2357 
2358 bool os::numa_topology_changed() {
2359   return false;
2360 }
2361 
2362 size_t os::numa_get_groups_num() {
2363   return 1;
2364 }
2365 
2366 int os::numa_get_group_id() {
2367   return 0;
2368 }
2369 
2370 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2371   if (size > 0) {
2372     ids[0] = 0;
2373     return 1;
2374   }
2375   return 0;
2376 }
2377 
2378 bool os::get_page_info(char *start, page_info* info) {
2379   return false;
2380 }
2381 
2382 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2383   return end;
2384 }
2385 
2386 // Reserves and attaches a shared memory segment.
2387 // Will assert if a wish address is given and could not be obtained.
2388 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, size_t alignment_hint) {
2389 
2390   // All other Unices do a mmap(MAP_FIXED) if the addr is given,
2391   // thereby clobbering old mappings at that place. That is probably
2392   // not intended, never used and almost certainly an error were it
2393   // ever be used this way (to try attaching at a specified address
2394   // without clobbering old mappings an alternate API exists,
2395   // os::attempt_reserve_memory_at()).
2396   // Instead of mimicking the dangerous coding of the other platforms, here I
2397   // just ignore the request address (release) or assert(debug).
2398   assert0(requested_addr == NULL);
2399 
2400   // Always round to os::vm_page_size(), which may be larger than 4K.
2401   bytes = align_up(bytes, os::vm_page_size());
2402   const size_t alignment_hint0 =
2403     alignment_hint ? align_up(alignment_hint, os::vm_page_size()) : 0;
2404 
2405   // In 4K mode always use mmap.
2406   // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2407   if (os::vm_page_size() == 4*K) {
2408     return reserve_mmaped_memory(bytes, requested_addr, alignment_hint);
2409   } else {
2410     if (bytes >= Use64KPagesThreshold) {
2411       return reserve_shmated_memory(bytes, requested_addr, alignment_hint);
2412     } else {
2413       return reserve_mmaped_memory(bytes, requested_addr, alignment_hint);
2414     }
2415   }
2416 }
2417 
2418 bool os::pd_release_memory(char* addr, size_t size) {
2419 
2420   // Dynamically do different things for mmap/shmat.
2421   vmembk_t* const vmi = vmembk_find(addr);
2422   guarantee0(vmi);
2423 
2424   // Always round to os::vm_page_size(), which may be larger than 4K.
2425   size = align_up(size, os::vm_page_size());
2426   addr = align_up(addr, os::vm_page_size());
2427 
2428   bool rc = false;
2429   bool remove_bookkeeping = false;
2430   if (vmi->type == VMEM_SHMATED) {
2431     // For shmatted memory, we do:
2432     // - If user wants to release the whole range, release the memory (shmdt).
2433     // - If user only wants to release a partial range, uncommit (disclaim) that
2434     //   range. That way, at least, we do not use memory anymore (bust still page
2435     //   table space).
2436     vmi->assert_is_valid_subrange(addr, size);
2437     if (addr == vmi->addr && size == vmi->size) {
2438       rc = release_shmated_memory(addr, size);
2439       remove_bookkeeping = true;
2440     } else {
2441       rc = uncommit_shmated_memory(addr, size);
2442     }
2443   } else {
2444     // User may unmap partial regions but region has to be fully contained.
2445 #ifdef ASSERT
2446     vmi->assert_is_valid_subrange(addr, size);
2447 #endif
2448     rc = release_mmaped_memory(addr, size);
2449     remove_bookkeeping = true;
2450   }
2451 
2452   // update bookkeeping
2453   if (rc && remove_bookkeeping) {
2454     vmembk_remove(vmi);
2455   }
2456 
2457   return rc;
2458 }
2459 
2460 static bool checked_mprotect(char* addr, size_t size, int prot) {
2461 
2462   // Little problem here: if SPEC1170 behaviour is off, mprotect() on AIX will
2463   // not tell me if protection failed when trying to protect an un-protectable range.
2464   //
2465   // This means if the memory was allocated using shmget/shmat, protection wont work
2466   // but mprotect will still return 0:
2467   //
2468   // See http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.basetechref/doc/basetrf1/mprotect.htm
2469 
2470   bool rc = ::mprotect(addr, size, prot) == 0 ? true : false;
2471 
2472   if (!rc) {
2473     const char* const s_errno = os::errno_name(errno);
2474     warning("mprotect(" PTR_FORMAT "-" PTR_FORMAT ", 0x%X) failed (%s).", addr, addr + size, prot, s_errno);
2475     return false;
2476   }
2477 
2478   // mprotect success check
2479   //
2480   // Mprotect said it changed the protection but can I believe it?
2481   //
2482   // To be sure I need to check the protection afterwards. Try to
2483   // read from protected memory and check whether that causes a segfault.
2484   //
2485   if (!os::Aix::xpg_sus_mode()) {
2486 
2487     if (CanUseSafeFetch32()) {
2488 
2489       const bool read_protected =
2490         (SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
2491          SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
2492 
2493       if (prot & PROT_READ) {
2494         rc = !read_protected;
2495       } else {
2496         rc = read_protected;
2497       }
2498 
2499       if (!rc) {
2500         if (os::Aix::on_pase()) {
2501           // There is an issue on older PASE systems where mprotect() will return success but the
2502           // memory will not be protected.
2503           // This has nothing to do with the problem of using mproect() on SPEC1170 incompatible
2504           // machines; we only see it rarely, when using mprotect() to protect the guard page of
2505           // a stack. It is an OS error.
2506           //
2507           // A valid strategy is just to try again. This usually works. :-/
2508 
2509           ::usleep(1000);
2510           if (::mprotect(addr, size, prot) == 0) {
2511             const bool read_protected_2 =
2512               (SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
2513               SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
2514             rc = true;
2515           }
2516         }
2517       }
2518     }
2519   }
2520 
2521   assert(rc == true, "mprotect failed.");
2522 
2523   return rc;
2524 }
2525 
2526 // Set protections specified
2527 bool os::protect_memory(char* addr, size_t size, ProtType prot, bool is_committed) {
2528   unsigned int p = 0;
2529   switch (prot) {
2530   case MEM_PROT_NONE: p = PROT_NONE; break;
2531   case MEM_PROT_READ: p = PROT_READ; break;
2532   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2533   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2534   default:
2535     ShouldNotReachHere();
2536   }
2537   // is_committed is unused.
2538   return checked_mprotect(addr, size, p);
2539 }
2540 
2541 bool os::guard_memory(char* addr, size_t size) {
2542   return checked_mprotect(addr, size, PROT_NONE);
2543 }
2544 
2545 bool os::unguard_memory(char* addr, size_t size) {
2546   return checked_mprotect(addr, size, PROT_READ|PROT_WRITE|PROT_EXEC);
2547 }
2548 
2549 // Large page support
2550 
2551 static size_t _large_page_size = 0;
2552 
2553 // Enable large page support if OS allows that.
2554 void os::large_page_init() {
2555   return; // Nothing to do. See query_multipage_support and friends.
2556 }
2557 
2558 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2559   // reserve_memory_special() is used to allocate large paged memory. On AIX, we implement
2560   // 64k paged memory reservation using the normal memory allocation paths (os::reserve_memory()),
2561   // so this is not needed.
2562   assert(false, "should not be called on AIX");
2563   return NULL;
2564 }
2565 
2566 bool os::release_memory_special(char* base, size_t bytes) {
2567   // Detaching the SHM segment will also delete it, see reserve_memory_special().
2568   Unimplemented();
2569   return false;
2570 }
2571 
2572 size_t os::large_page_size() {
2573   return _large_page_size;
2574 }
2575 
2576 bool os::can_commit_large_page_memory() {
2577   // Does not matter, we do not support huge pages.
2578   return false;
2579 }
2580 
2581 bool os::can_execute_large_page_memory() {
2582   // Does not matter, we do not support huge pages.
2583   return false;
2584 }
2585 
2586 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2587   assert(file_desc >= 0, "file_desc is not valid");
2588   char* result = NULL;
2589 
2590   // Always round to os::vm_page_size(), which may be larger than 4K.
2591   bytes = align_up(bytes, os::vm_page_size());
2592   result = reserve_mmaped_memory(bytes, requested_addr, 0);
2593 
2594   if (result != NULL) {
2595     if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2596       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2597     }
2598   }
2599   return result;
2600 }
2601 
2602 // Reserve memory at an arbitrary address, only if that area is
2603 // available (and not reserved for something else).
2604 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2605   char* addr = NULL;
2606 
2607   // Always round to os::vm_page_size(), which may be larger than 4K.
2608   bytes = align_up(bytes, os::vm_page_size());
2609 
2610   // In 4K mode always use mmap.
2611   // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2612   if (os::vm_page_size() == 4*K) {
2613     return reserve_mmaped_memory(bytes, requested_addr, 0);
2614   } else {
2615     if (bytes >= Use64KPagesThreshold) {
2616       return reserve_shmated_memory(bytes, requested_addr, 0);
2617     } else {
2618       return reserve_mmaped_memory(bytes, requested_addr, 0);
2619     }
2620   }
2621 
2622   return addr;
2623 }
2624 
2625 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2626   return ::read(fd, buf, nBytes);
2627 }
2628 
2629 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
2630   return ::pread(fd, buf, nBytes, offset);
2631 }
2632 
2633 void os::naked_short_sleep(jlong ms) {
2634   struct timespec req;
2635 
2636   assert(ms < 1000, "Un-interruptable sleep, short time use only");
2637   req.tv_sec = 0;
2638   if (ms > 0) {
2639     req.tv_nsec = (ms % 1000) * 1000000;
2640   }
2641   else {
2642     req.tv_nsec = 1;
2643   }
2644 
2645   nanosleep(&req, NULL);
2646 
2647   return;
2648 }
2649 
2650 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2651 void os::infinite_sleep() {
2652   while (true) {    // sleep forever ...
2653     ::sleep(100);   // ... 100 seconds at a time
2654   }
2655 }
2656 
2657 // Used to convert frequent JVM_Yield() to nops
2658 bool os::dont_yield() {
2659   return DontYieldALot;
2660 }
2661 
2662 void os::naked_yield() {
2663   sched_yield();
2664 }
2665 
2666 ////////////////////////////////////////////////////////////////////////////////
2667 // thread priority support
2668 
2669 // From AIX manpage to pthread_setschedparam
2670 // (see: http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?
2671 //    topic=/com.ibm.aix.basetechref/doc/basetrf1/pthread_setschedparam.htm):
2672 //
2673 // "If schedpolicy is SCHED_OTHER, then sched_priority must be in the
2674 // range from 40 to 80, where 40 is the least favored priority and 80
2675 // is the most favored."
2676 //
2677 // (Actually, I doubt this even has an impact on AIX, as we do kernel
2678 // scheduling there; however, this still leaves iSeries.)
2679 //
2680 // We use the same values for AIX and PASE.
2681 int os::java_to_os_priority[CriticalPriority + 1] = {
2682   54,             // 0 Entry should never be used
2683 
2684   55,             // 1 MinPriority
2685   55,             // 2
2686   56,             // 3
2687 
2688   56,             // 4
2689   57,             // 5 NormPriority
2690   57,             // 6
2691 
2692   58,             // 7
2693   58,             // 8
2694   59,             // 9 NearMaxPriority
2695 
2696   60,             // 10 MaxPriority
2697 
2698   60              // 11 CriticalPriority
2699 };
2700 
2701 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2702   if (!UseThreadPriorities) return OS_OK;
2703   pthread_t thr = thread->osthread()->pthread_id();
2704   int policy = SCHED_OTHER;
2705   struct sched_param param;
2706   param.sched_priority = newpri;
2707   int ret = pthread_setschedparam(thr, policy, &param);
2708 
2709   if (ret != 0) {
2710     trcVerbose("Could not change priority for thread %d to %d (error %d, %s)",
2711         (int)thr, newpri, ret, os::errno_name(ret));
2712   }
2713   return (ret == 0) ? OS_OK : OS_ERR;
2714 }
2715 
2716 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2717   if (!UseThreadPriorities) {
2718     *priority_ptr = java_to_os_priority[NormPriority];
2719     return OS_OK;
2720   }
2721   pthread_t thr = thread->osthread()->pthread_id();
2722   int policy = SCHED_OTHER;
2723   struct sched_param param;
2724   int ret = pthread_getschedparam(thr, &policy, &param);
2725   *priority_ptr = param.sched_priority;
2726 
2727   return (ret == 0) ? OS_OK : OS_ERR;
2728 }
2729 
2730 // Hint to the underlying OS that a task switch would not be good.
2731 // Void return because it's a hint and can fail.
2732 void os::hint_no_preempt() {}
2733 
2734 ////////////////////////////////////////////////////////////////////////////////
2735 // suspend/resume support
2736 
2737 //  The low-level signal-based suspend/resume support is a remnant from the
2738 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2739 //  within hotspot. Currently used by JFR's OSThreadSampler
2740 //
2741 //  The remaining code is greatly simplified from the more general suspension
2742 //  code that used to be used.
2743 //
2744 //  The protocol is quite simple:
2745 //  - suspend:
2746 //      - sends a signal to the target thread
2747 //      - polls the suspend state of the osthread using a yield loop
2748 //      - target thread signal handler (SR_handler) sets suspend state
2749 //        and blocks in sigsuspend until continued
2750 //  - resume:
2751 //      - sets target osthread state to continue
2752 //      - sends signal to end the sigsuspend loop in the SR_handler
2753 //
2754 //  Note that the SR_lock plays no role in this suspend/resume protocol,
2755 //  but is checked for NULL in SR_handler as a thread termination indicator.
2756 //  The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
2757 //
2758 //  Note that resume_clear_context() and suspend_save_context() are needed
2759 //  by SR_handler(), so that fetch_frame_from_ucontext() works,
2760 //  which in part is used by:
2761 //    - Forte Analyzer: AsyncGetCallTrace()
2762 //    - StackBanging: get_frame_at_stack_banging_point()
2763 
2764 static void resume_clear_context(OSThread *osthread) {
2765   osthread->set_ucontext(NULL);
2766   osthread->set_siginfo(NULL);
2767 }
2768 
2769 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2770   osthread->set_ucontext(context);
2771   osthread->set_siginfo(siginfo);
2772 }
2773 
2774 //
2775 // Handler function invoked when a thread's execution is suspended or
2776 // resumed. We have to be careful that only async-safe functions are
2777 // called here (Note: most pthread functions are not async safe and
2778 // should be avoided.)
2779 //
2780 // Note: sigwait() is a more natural fit than sigsuspend() from an
2781 // interface point of view, but sigwait() prevents the signal hander
2782 // from being run. libpthread would get very confused by not having
2783 // its signal handlers run and prevents sigwait()'s use with the
2784 // mutex granting granting signal.
2785 //
2786 // Currently only ever called on the VMThread and JavaThreads (PC sampling).
2787 //
2788 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2789   // Save and restore errno to avoid confusing native code with EINTR
2790   // after sigsuspend.
2791   int old_errno = errno;
2792 
2793   Thread* thread = Thread::current_or_null_safe();
2794   assert(thread != NULL, "Missing current thread in SR_handler");
2795 
2796   // On some systems we have seen signal delivery get "stuck" until the signal
2797   // mask is changed as part of thread termination. Check that the current thread
2798   // has not already terminated (via SR_lock()) - else the following assertion
2799   // will fail because the thread is no longer a JavaThread as the ~JavaThread
2800   // destructor has completed.
2801 
2802   if (thread->SR_lock() == NULL) {
2803     return;
2804   }
2805 
2806   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2807 
2808   OSThread* osthread = thread->osthread();
2809 
2810   os::SuspendResume::State current = osthread->sr.state();
2811   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2812     suspend_save_context(osthread, siginfo, context);
2813 
2814     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2815     os::SuspendResume::State state = osthread->sr.suspended();
2816     if (state == os::SuspendResume::SR_SUSPENDED) {
2817       sigset_t suspend_set;  // signals for sigsuspend()
2818 
2819       // get current set of blocked signals and unblock resume signal
2820       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2821       sigdelset(&suspend_set, SR_signum);
2822 
2823       // wait here until we are resumed
2824       while (1) {
2825         sigsuspend(&suspend_set);
2826 
2827         os::SuspendResume::State result = osthread->sr.running();
2828         if (result == os::SuspendResume::SR_RUNNING) {
2829           break;
2830         }
2831       }
2832 
2833     } else if (state == os::SuspendResume::SR_RUNNING) {
2834       // request was cancelled, continue
2835     } else {
2836       ShouldNotReachHere();
2837     }
2838 
2839     resume_clear_context(osthread);
2840   } else if (current == os::SuspendResume::SR_RUNNING) {
2841     // request was cancelled, continue
2842   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2843     // ignore
2844   } else {
2845     ShouldNotReachHere();
2846   }
2847 
2848   errno = old_errno;
2849 }
2850 
2851 static int SR_initialize() {
2852   struct sigaction act;
2853   char *s;
2854   // Get signal number to use for suspend/resume
2855   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2856     int sig = ::strtol(s, 0, 10);
2857     if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
2858         sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
2859       SR_signum = sig;
2860     } else {
2861       warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2862               sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2863     }
2864   }
2865 
2866   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2867         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2868 
2869   sigemptyset(&SR_sigset);
2870   sigaddset(&SR_sigset, SR_signum);
2871 
2872   // Set up signal handler for suspend/resume.
2873   act.sa_flags = SA_RESTART|SA_SIGINFO;
2874   act.sa_handler = (void (*)(int)) SR_handler;
2875 
2876   // SR_signum is blocked by default.
2877   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2878 
2879   if (sigaction(SR_signum, &act, 0) == -1) {
2880     return -1;
2881   }
2882 
2883   // Save signal flag
2884   os::Aix::set_our_sigflags(SR_signum, act.sa_flags);
2885   return 0;
2886 }
2887 
2888 static int SR_finalize() {
2889   return 0;
2890 }
2891 
2892 static int sr_notify(OSThread* osthread) {
2893   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2894   assert_status(status == 0, status, "pthread_kill");
2895   return status;
2896 }
2897 
2898 // "Randomly" selected value for how long we want to spin
2899 // before bailing out on suspending a thread, also how often
2900 // we send a signal to a thread we want to resume
2901 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2902 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2903 
2904 // returns true on success and false on error - really an error is fatal
2905 // but this seems the normal response to library errors
2906 static bool do_suspend(OSThread* osthread) {
2907   assert(osthread->sr.is_running(), "thread should be running");
2908   // mark as suspended and send signal
2909 
2910   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2911     // failed to switch, state wasn't running?
2912     ShouldNotReachHere();
2913     return false;
2914   }
2915 
2916   if (sr_notify(osthread) != 0) {
2917     // try to cancel, switch to running
2918 
2919     os::SuspendResume::State result = osthread->sr.cancel_suspend();
2920     if (result == os::SuspendResume::SR_RUNNING) {
2921       // cancelled
2922       return false;
2923     } else if (result == os::SuspendResume::SR_SUSPENDED) {
2924       // somehow managed to suspend
2925       return true;
2926     } else {
2927       ShouldNotReachHere();
2928       return false;
2929     }
2930   }
2931 
2932   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2933 
2934   for (int n = 0; !osthread->sr.is_suspended(); n++) {
2935     for (int i = 0; i < RANDOMLY_LARGE_INTEGER2 && !osthread->sr.is_suspended(); i++) {
2936       os::naked_yield();
2937     }
2938 
2939     // timeout, try to cancel the request
2940     if (n >= RANDOMLY_LARGE_INTEGER) {
2941       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2942       if (cancelled == os::SuspendResume::SR_RUNNING) {
2943         return false;
2944       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2945         return true;
2946       } else {
2947         ShouldNotReachHere();
2948         return false;
2949       }
2950     }
2951   }
2952 
2953   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2954   return true;
2955 }
2956 
2957 static void do_resume(OSThread* osthread) {
2958   //assert(osthread->sr.is_suspended(), "thread should be suspended");
2959 
2960   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2961     // failed to switch to WAKEUP_REQUEST
2962     ShouldNotReachHere();
2963     return;
2964   }
2965 
2966   while (!osthread->sr.is_running()) {
2967     if (sr_notify(osthread) == 0) {
2968       for (int n = 0; n < RANDOMLY_LARGE_INTEGER && !osthread->sr.is_running(); n++) {
2969         for (int i = 0; i < 100 && !osthread->sr.is_running(); i++) {
2970           os::naked_yield();
2971         }
2972       }
2973     } else {
2974       ShouldNotReachHere();
2975     }
2976   }
2977 
2978   guarantee(osthread->sr.is_running(), "Must be running!");
2979 }
2980 
2981 ///////////////////////////////////////////////////////////////////////////////////
2982 // signal handling (except suspend/resume)
2983 
2984 // This routine may be used by user applications as a "hook" to catch signals.
2985 // The user-defined signal handler must pass unrecognized signals to this
2986 // routine, and if it returns true (non-zero), then the signal handler must
2987 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2988 // routine will never retun false (zero), but instead will execute a VM panic
2989 // routine kill the process.
2990 //
2991 // If this routine returns false, it is OK to call it again. This allows
2992 // the user-defined signal handler to perform checks either before or after
2993 // the VM performs its own checks. Naturally, the user code would be making
2994 // a serious error if it tried to handle an exception (such as a null check
2995 // or breakpoint) that the VM was generating for its own correct operation.
2996 //
2997 // This routine may recognize any of the following kinds of signals:
2998 //   SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2999 // It should be consulted by handlers for any of those signals.
3000 //
3001 // The caller of this routine must pass in the three arguments supplied
3002 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
3003 // field of the structure passed to sigaction(). This routine assumes that
3004 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
3005 //
3006 // Note that the VM will print warnings if it detects conflicting signal
3007 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
3008 //
3009 extern "C" JNIEXPORT int
3010 JVM_handle_aix_signal(int signo, siginfo_t* siginfo, void* ucontext, int abort_if_unrecognized);
3011 
3012 // Set thread signal mask (for some reason on AIX sigthreadmask() seems
3013 // to be the thing to call; documentation is not terribly clear about whether
3014 // pthread_sigmask also works, and if it does, whether it does the same.
3015 bool set_thread_signal_mask(int how, const sigset_t* set, sigset_t* oset) {
3016   const int rc = ::pthread_sigmask(how, set, oset);
3017   // return value semantics differ slightly for error case:
3018   // pthread_sigmask returns error number, sigthreadmask -1 and sets global errno
3019   // (so, pthread_sigmask is more theadsafe for error handling)
3020   // But success is always 0.
3021   return rc == 0 ? true : false;
3022 }
3023 
3024 // Function to unblock all signals which are, according
3025 // to POSIX, typical program error signals. If they happen while being blocked,
3026 // they typically will bring down the process immediately.
3027 bool unblock_program_error_signals() {
3028   sigset_t set;
3029   ::sigemptyset(&set);
3030   ::sigaddset(&set, SIGILL);
3031   ::sigaddset(&set, SIGBUS);
3032   ::sigaddset(&set, SIGFPE);
3033   ::sigaddset(&set, SIGSEGV);
3034   return set_thread_signal_mask(SIG_UNBLOCK, &set, NULL);
3035 }
3036 
3037 // Renamed from 'signalHandler' to avoid collision with other shared libs.
3038 static void javaSignalHandler(int sig, siginfo_t* info, void* uc) {
3039   assert(info != NULL && uc != NULL, "it must be old kernel");
3040 
3041   // Never leave program error signals blocked;
3042   // on all our platforms they would bring down the process immediately when
3043   // getting raised while being blocked.
3044   unblock_program_error_signals();
3045 
3046   int orig_errno = errno;  // Preserve errno value over signal handler.
3047   JVM_handle_aix_signal(sig, info, uc, true);
3048   errno = orig_errno;
3049 }
3050 
3051 // This boolean allows users to forward their own non-matching signals
3052 // to JVM_handle_aix_signal, harmlessly.
3053 bool os::Aix::signal_handlers_are_installed = false;
3054 
3055 // For signal-chaining
3056 struct sigaction sigact[NSIG];
3057 sigset_t sigs;
3058 bool os::Aix::libjsig_is_loaded = false;
3059 typedef struct sigaction *(*get_signal_t)(int);
3060 get_signal_t os::Aix::get_signal_action = NULL;
3061 
3062 struct sigaction* os::Aix::get_chained_signal_action(int sig) {
3063   struct sigaction *actp = NULL;
3064 
3065   if (libjsig_is_loaded) {
3066     // Retrieve the old signal handler from libjsig
3067     actp = (*get_signal_action)(sig);
3068   }
3069   if (actp == NULL) {
3070     // Retrieve the preinstalled signal handler from jvm
3071     actp = get_preinstalled_handler(sig);
3072   }
3073 
3074   return actp;
3075 }
3076 
3077 static bool call_chained_handler(struct sigaction *actp, int sig,
3078                                  siginfo_t *siginfo, void *context) {
3079   // Call the old signal handler
3080   if (actp->sa_handler == SIG_DFL) {
3081     // It's more reasonable to let jvm treat it as an unexpected exception
3082     // instead of taking the default action.
3083     return false;
3084   } else if (actp->sa_handler != SIG_IGN) {
3085     if ((actp->sa_flags & SA_NODEFER) == 0) {
3086       // automaticlly block the signal
3087       sigaddset(&(actp->sa_mask), sig);
3088     }
3089 
3090     sa_handler_t hand = NULL;
3091     sa_sigaction_t sa = NULL;
3092     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3093     // retrieve the chained handler
3094     if (siginfo_flag_set) {
3095       sa = actp->sa_sigaction;
3096     } else {
3097       hand = actp->sa_handler;
3098     }
3099 
3100     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3101       actp->sa_handler = SIG_DFL;
3102     }
3103 
3104     // try to honor the signal mask
3105     sigset_t oset;
3106     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3107 
3108     // call into the chained handler
3109     if (siginfo_flag_set) {
3110       (*sa)(sig, siginfo, context);
3111     } else {
3112       (*hand)(sig);
3113     }
3114 
3115     // restore the signal mask
3116     pthread_sigmask(SIG_SETMASK, &oset, 0);
3117   }
3118   // Tell jvm's signal handler the signal is taken care of.
3119   return true;
3120 }
3121 
3122 bool os::Aix::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3123   bool chained = false;
3124   // signal-chaining
3125   if (UseSignalChaining) {
3126     struct sigaction *actp = get_chained_signal_action(sig);
3127     if (actp != NULL) {
3128       chained = call_chained_handler(actp, sig, siginfo, context);
3129     }
3130   }
3131   return chained;
3132 }
3133 
3134 struct sigaction* os::Aix::get_preinstalled_handler(int sig) {
3135   if (sigismember(&sigs, sig)) {
3136     return &sigact[sig];
3137   }
3138   return NULL;
3139 }
3140 
3141 void os::Aix::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3142   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3143   sigact[sig] = oldAct;
3144   sigaddset(&sigs, sig);
3145 }
3146 
3147 // for diagnostic
3148 int sigflags[NSIG];
3149 
3150 int os::Aix::get_our_sigflags(int sig) {
3151   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3152   return sigflags[sig];
3153 }
3154 
3155 void os::Aix::set_our_sigflags(int sig, int flags) {
3156   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3157   if (sig > 0 && sig < NSIG) {
3158     sigflags[sig] = flags;
3159   }
3160 }
3161 
3162 void os::Aix::set_signal_handler(int sig, bool set_installed) {
3163   // Check for overwrite.
3164   struct sigaction oldAct;
3165   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3166 
3167   void* oldhand = oldAct.sa_sigaction
3168     ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3169     : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3170   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3171       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3172       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)javaSignalHandler)) {
3173     if (AllowUserSignalHandlers || !set_installed) {
3174       // Do not overwrite; user takes responsibility to forward to us.
3175       return;
3176     } else if (UseSignalChaining) {
3177       // save the old handler in jvm
3178       save_preinstalled_handler(sig, oldAct);
3179       // libjsig also interposes the sigaction() call below and saves the
3180       // old sigaction on it own.
3181     } else {
3182       fatal("Encountered unexpected pre-existing sigaction handler "
3183             "%#lx for signal %d.", (long)oldhand, sig);
3184     }
3185   }
3186 
3187   struct sigaction sigAct;
3188   sigfillset(&(sigAct.sa_mask));
3189   if (!set_installed) {
3190     sigAct.sa_handler = SIG_DFL;
3191     sigAct.sa_flags = SA_RESTART;
3192   } else {
3193     sigAct.sa_sigaction = javaSignalHandler;
3194     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3195   }
3196   // Save flags, which are set by ours
3197   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3198   sigflags[sig] = sigAct.sa_flags;
3199 
3200   int ret = sigaction(sig, &sigAct, &oldAct);
3201   assert(ret == 0, "check");
3202 
3203   void* oldhand2 = oldAct.sa_sigaction
3204                  ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3205                  : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3206   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3207 }
3208 
3209 // install signal handlers for signals that HotSpot needs to
3210 // handle in order to support Java-level exception handling.
3211 void os::Aix::install_signal_handlers() {
3212   if (!signal_handlers_are_installed) {
3213     signal_handlers_are_installed = true;
3214 
3215     // signal-chaining
3216     typedef void (*signal_setting_t)();
3217     signal_setting_t begin_signal_setting = NULL;
3218     signal_setting_t end_signal_setting = NULL;
3219     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3220                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3221     if (begin_signal_setting != NULL) {
3222       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3223                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3224       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3225                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3226       libjsig_is_loaded = true;
3227       assert(UseSignalChaining, "should enable signal-chaining");
3228     }
3229     if (libjsig_is_loaded) {
3230       // Tell libjsig jvm is setting signal handlers.
3231       (*begin_signal_setting)();
3232     }
3233 
3234     ::sigemptyset(&sigs);
3235     set_signal_handler(SIGSEGV, true);
3236     set_signal_handler(SIGPIPE, true);
3237     set_signal_handler(SIGBUS, true);
3238     set_signal_handler(SIGILL, true);
3239     set_signal_handler(SIGFPE, true);
3240     set_signal_handler(SIGTRAP, true);
3241     set_signal_handler(SIGXFSZ, true);
3242 
3243     if (libjsig_is_loaded) {
3244       // Tell libjsig jvm finishes setting signal handlers.
3245       (*end_signal_setting)();
3246     }
3247 
3248     // We don't activate signal checker if libjsig is in place, we trust ourselves
3249     // and if UserSignalHandler is installed all bets are off.
3250     // Log that signal checking is off only if -verbose:jni is specified.
3251     if (CheckJNICalls) {
3252       if (libjsig_is_loaded) {
3253         tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3254         check_signals = false;
3255       }
3256       if (AllowUserSignalHandlers) {
3257         tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3258         check_signals = false;
3259       }
3260       // Need to initialize check_signal_done.
3261       ::sigemptyset(&check_signal_done);
3262     }
3263   }
3264 }
3265 
3266 static const char* get_signal_handler_name(address handler,
3267                                            char* buf, int buflen) {
3268   int offset;
3269   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3270   if (found) {
3271     // skip directory names
3272     const char *p1, *p2;
3273     p1 = buf;
3274     size_t len = strlen(os::file_separator());
3275     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3276     // The way os::dll_address_to_library_name is implemented on Aix
3277     // right now, it always returns -1 for the offset which is not
3278     // terribly informative.
3279     // Will fix that. For now, omit the offset.
3280     jio_snprintf(buf, buflen, "%s", p1);
3281   } else {
3282     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3283   }
3284   return buf;
3285 }
3286 
3287 static void print_signal_handler(outputStream* st, int sig,
3288                                  char* buf, size_t buflen) {
3289   struct sigaction sa;
3290   sigaction(sig, NULL, &sa);
3291 
3292   st->print("%s: ", os::exception_name(sig, buf, buflen));
3293 
3294   address handler = (sa.sa_flags & SA_SIGINFO)
3295     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3296     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3297 
3298   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3299     st->print("SIG_DFL");
3300   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3301     st->print("SIG_IGN");
3302   } else {
3303     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3304   }
3305 
3306   // Print readable mask.
3307   st->print(", sa_mask[0]=");
3308   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3309 
3310   address rh = VMError::get_resetted_sighandler(sig);
3311   // May be, handler was resetted by VMError?
3312   if (rh != NULL) {
3313     handler = rh;
3314     sa.sa_flags = VMError::get_resetted_sigflags(sig);
3315   }
3316 
3317   // Print textual representation of sa_flags.
3318   st->print(", sa_flags=");
3319   os::Posix::print_sa_flags(st, sa.sa_flags);
3320 
3321   // Check: is it our handler?
3322   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)javaSignalHandler) ||
3323       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3324     // It is our signal handler.
3325     // Check for flags, reset system-used one!
3326     if ((int)sa.sa_flags != os::Aix::get_our_sigflags(sig)) {
3327       st->print(", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3328                 os::Aix::get_our_sigflags(sig));
3329     }
3330   }
3331   st->cr();
3332 }
3333 
3334 #define DO_SIGNAL_CHECK(sig) \
3335   if (!sigismember(&check_signal_done, sig)) \
3336     os::Aix::check_signal_handler(sig)
3337 
3338 // This method is a periodic task to check for misbehaving JNI applications
3339 // under CheckJNI, we can add any periodic checks here
3340 
3341 void os::run_periodic_checks() {
3342 
3343   if (check_signals == false) return;
3344 
3345   // SEGV and BUS if overridden could potentially prevent
3346   // generation of hs*.log in the event of a crash, debugging
3347   // such a case can be very challenging, so we absolutely
3348   // check the following for a good measure:
3349   DO_SIGNAL_CHECK(SIGSEGV);
3350   DO_SIGNAL_CHECK(SIGILL);
3351   DO_SIGNAL_CHECK(SIGFPE);
3352   DO_SIGNAL_CHECK(SIGBUS);
3353   DO_SIGNAL_CHECK(SIGPIPE);
3354   DO_SIGNAL_CHECK(SIGXFSZ);
3355   if (UseSIGTRAP) {
3356     DO_SIGNAL_CHECK(SIGTRAP);
3357   }
3358 
3359   // ReduceSignalUsage allows the user to override these handlers
3360   // see comments at the very top and jvm_md.h
3361   if (!ReduceSignalUsage) {
3362     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3363     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3364     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3365     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3366   }
3367 
3368   DO_SIGNAL_CHECK(SR_signum);
3369 }
3370 
3371 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3372 
3373 static os_sigaction_t os_sigaction = NULL;
3374 
3375 void os::Aix::check_signal_handler(int sig) {
3376   char buf[O_BUFLEN];
3377   address jvmHandler = NULL;
3378 
3379   struct sigaction act;
3380   if (os_sigaction == NULL) {
3381     // only trust the default sigaction, in case it has been interposed
3382     os_sigaction = CAST_TO_FN_PTR(os_sigaction_t, dlsym(RTLD_DEFAULT, "sigaction"));
3383     if (os_sigaction == NULL) return;
3384   }
3385 
3386   os_sigaction(sig, (struct sigaction*)NULL, &act);
3387 
3388   address thisHandler = (act.sa_flags & SA_SIGINFO)
3389     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3390     : CAST_FROM_FN_PTR(address, act.sa_handler);
3391 
3392   switch(sig) {
3393   case SIGSEGV:
3394   case SIGBUS:
3395   case SIGFPE:
3396   case SIGPIPE:
3397   case SIGILL:
3398   case SIGXFSZ:
3399     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)javaSignalHandler);
3400     break;
3401 
3402   case SHUTDOWN1_SIGNAL:
3403   case SHUTDOWN2_SIGNAL:
3404   case SHUTDOWN3_SIGNAL:
3405   case BREAK_SIGNAL:
3406     jvmHandler = (address)user_handler();
3407     break;
3408 
3409   default:
3410     if (sig == SR_signum) {
3411       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3412     } else {
3413       return;
3414     }
3415     break;
3416   }
3417 
3418   if (thisHandler != jvmHandler) {
3419     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3420     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3421     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3422     // No need to check this sig any longer
3423     sigaddset(&check_signal_done, sig);
3424     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3425     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3426       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3427                     exception_name(sig, buf, O_BUFLEN));
3428     }
3429   } else if (os::Aix::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Aix::get_our_sigflags(sig)) {
3430     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3431     tty->print("expected:");
3432     os::Posix::print_sa_flags(tty, os::Aix::get_our_sigflags(sig));
3433     tty->cr();
3434     tty->print("  found:");
3435     os::Posix::print_sa_flags(tty, act.sa_flags);
3436     tty->cr();
3437     // No need to check this sig any longer
3438     sigaddset(&check_signal_done, sig);
3439   }
3440 
3441   // Dump all the signal
3442   if (sigismember(&check_signal_done, sig)) {
3443     print_signal_handlers(tty, buf, O_BUFLEN);
3444   }
3445 }
3446 
3447 // To install functions for atexit system call
3448 extern "C" {
3449   static void perfMemory_exit_helper() {
3450     perfMemory_exit();
3451   }
3452 }
3453 
3454 // This is called _before_ the most of global arguments have been parsed.
3455 void os::init(void) {
3456   // This is basic, we want to know if that ever changes.
3457   // (Shared memory boundary is supposed to be a 256M aligned.)
3458   assert(SHMLBA == ((uint64_t)0x10000000ULL)/*256M*/, "unexpected");
3459 
3460   // Record process break at startup.
3461   g_brk_at_startup = (address) ::sbrk(0);
3462   assert(g_brk_at_startup != (address) -1, "sbrk failed");
3463 
3464   // First off, we need to know whether we run on AIX or PASE, and
3465   // the OS level we run on.
3466   os::Aix::initialize_os_info();
3467 
3468   // Scan environment (SPEC1170 behaviour, etc).
3469   os::Aix::scan_environment();
3470 
3471   // Probe multipage support.
3472   query_multipage_support();
3473 
3474   // Act like we only have one page size by eliminating corner cases which
3475   // we did not support very well anyway.
3476   // We have two input conditions:
3477   // 1) Data segment page size. This is controlled by linker setting (datapsize) on the
3478   //    launcher, and/or by LDR_CNTRL environment variable. The latter overrules the linker
3479   //    setting.
3480   //    Data segment page size is important for us because it defines the thread stack page
3481   //    size, which is needed for guard page handling, stack banging etc.
3482   // 2) The ability to allocate 64k pages dynamically. If this is a given, java heap can
3483   //    and should be allocated with 64k pages.
3484   //
3485   // So, we do the following:
3486   // LDR_CNTRL    can_use_64K_pages_dynamically       what we do                      remarks
3487   // 4K           no                                  4K                              old systems (aix 5.2, as/400 v5r4) or new systems with AME activated
3488   // 4k           yes                                 64k (treat 4k stacks as 64k)    different loader than java and standard settings
3489   // 64k          no              --- AIX 5.2 ? ---
3490   // 64k          yes                                 64k                             new systems and standard java loader (we set datapsize=64k when linking)
3491 
3492   // We explicitly leave no option to change page size, because only upgrading would work,
3493   // not downgrading (if stack page size is 64k you cannot pretend its 4k).
3494 
3495   if (g_multipage_support.datapsize == 4*K) {
3496     // datapsize = 4K. Data segment, thread stacks are 4K paged.
3497     if (g_multipage_support.can_use_64K_pages) {
3498       // .. but we are able to use 64K pages dynamically.
3499       // This would be typical for java launchers which are not linked
3500       // with datapsize=64K (like, any other launcher but our own).
3501       //
3502       // In this case it would be smart to allocate the java heap with 64K
3503       // to get the performance benefit, and to fake 64k pages for the
3504       // data segment (when dealing with thread stacks).
3505       //
3506       // However, leave a possibility to downgrade to 4K, using
3507       // -XX:-Use64KPages.
3508       if (Use64KPages) {
3509         trcVerbose("64K page mode (faked for data segment)");
3510         Aix::_page_size = 64*K;
3511       } else {
3512         trcVerbose("4K page mode (Use64KPages=off)");
3513         Aix::_page_size = 4*K;
3514       }
3515     } else {
3516       // .. and not able to allocate 64k pages dynamically. Here, just
3517       // fall back to 4K paged mode and use mmap for everything.
3518       trcVerbose("4K page mode");
3519       Aix::_page_size = 4*K;
3520       FLAG_SET_ERGO(bool, Use64KPages, false);
3521     }
3522   } else {
3523     // datapsize = 64k. Data segment, thread stacks are 64k paged.
3524     // This normally means that we can allocate 64k pages dynamically.
3525     // (There is one special case where this may be false: EXTSHM=on.
3526     // but we decided to not support that mode).
3527     assert0(g_multipage_support.can_use_64K_pages);
3528     Aix::_page_size = 64*K;
3529     trcVerbose("64K page mode");
3530     FLAG_SET_ERGO(bool, Use64KPages, true);
3531   }
3532 
3533   // For now UseLargePages is just ignored.
3534   FLAG_SET_ERGO(bool, UseLargePages, false);
3535   _page_sizes[0] = 0;
3536 
3537   // debug trace
3538   trcVerbose("os::vm_page_size %s", describe_pagesize(os::vm_page_size()));
3539 
3540   // Next, we need to initialize libo4 and libperfstat libraries.
3541   if (os::Aix::on_pase()) {
3542     os::Aix::initialize_libo4();
3543   } else {
3544     os::Aix::initialize_libperfstat();
3545   }
3546 
3547   // Reset the perfstat information provided by ODM.
3548   if (os::Aix::on_aix()) {
3549     libperfstat::perfstat_reset();
3550   }
3551 
3552   // Now initialze basic system properties. Note that for some of the values we
3553   // need libperfstat etc.
3554   os::Aix::initialize_system_info();
3555 
3556   clock_tics_per_sec = sysconf(_SC_CLK_TCK);
3557 
3558   init_random(1234567);
3559 
3560   // _main_thread points to the thread that created/loaded the JVM.
3561   Aix::_main_thread = pthread_self();
3562 
3563   initial_time_count = os::elapsed_counter();
3564 
3565   os::Posix::init();
3566 }
3567 
3568 // This is called _after_ the global arguments have been parsed.
3569 jint os::init_2(void) {
3570 
3571   os::Posix::init_2();
3572 
3573   if (os::Aix::on_pase()) {
3574     trcVerbose("Running on PASE.");
3575   } else {
3576     trcVerbose("Running on AIX (not PASE).");
3577   }
3578 
3579   trcVerbose("processor count: %d", os::_processor_count);
3580   trcVerbose("physical memory: %lu", Aix::_physical_memory);
3581 
3582   // Initially build up the loaded dll map.
3583   LoadedLibraries::reload();
3584   if (Verbose) {
3585     trcVerbose("Loaded Libraries: ");
3586     LoadedLibraries::print(tty);
3587   }
3588 
3589   // initialize suspend/resume support - must do this before signal_sets_init()
3590   if (SR_initialize() != 0) {
3591     perror("SR_initialize failed");
3592     return JNI_ERR;
3593   }
3594 
3595   Aix::signal_sets_init();
3596   Aix::install_signal_handlers();
3597   // Initialize data for jdk.internal.misc.Signal
3598   if (!ReduceSignalUsage) {
3599     jdk_misc_signal_init();
3600   }
3601 
3602   // Check and sets minimum stack sizes against command line options
3603   if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
3604     return JNI_ERR;
3605   }
3606 
3607   if (UseNUMA) {
3608     UseNUMA = false;
3609     warning("NUMA optimizations are not available on this OS.");
3610   }
3611 
3612   if (MaxFDLimit) {
3613     // Set the number of file descriptors to max. print out error
3614     // if getrlimit/setrlimit fails but continue regardless.
3615     struct rlimit nbr_files;
3616     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3617     if (status != 0) {
3618       log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3619     } else {
3620       nbr_files.rlim_cur = nbr_files.rlim_max;
3621       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3622       if (status != 0) {
3623         log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3624       }
3625     }
3626   }
3627 
3628   if (PerfAllowAtExitRegistration) {
3629     // Only register atexit functions if PerfAllowAtExitRegistration is set.
3630     // At exit functions can be delayed until process exit time, which
3631     // can be problematic for embedded VM situations. Embedded VMs should
3632     // call DestroyJavaVM() to assure that VM resources are released.
3633 
3634     // Note: perfMemory_exit_helper atexit function may be removed in
3635     // the future if the appropriate cleanup code can be added to the
3636     // VM_Exit VMOperation's doit method.
3637     if (atexit(perfMemory_exit_helper) != 0) {
3638       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
3639     }
3640   }
3641 
3642   return JNI_OK;
3643 }
3644 
3645 // Mark the polling page as unreadable
3646 void os::make_polling_page_unreadable(void) {
3647   if (!guard_memory((char*)_polling_page, Aix::page_size())) {
3648     fatal("Could not disable polling page");
3649   }
3650 };
3651 
3652 // Mark the polling page as readable
3653 void os::make_polling_page_readable(void) {
3654   // Changed according to os_linux.cpp.
3655   if (!checked_mprotect((char *)_polling_page, Aix::page_size(), PROT_READ)) {
3656     fatal("Could not enable polling page at " PTR_FORMAT, _polling_page);
3657   }
3658 };
3659 
3660 int os::active_processor_count() {
3661   // User has overridden the number of active processors
3662   if (ActiveProcessorCount > 0) {
3663     log_trace(os)("active_processor_count: "
3664                   "active processor count set by user : %d",
3665                   ActiveProcessorCount);
3666     return ActiveProcessorCount;
3667   }
3668 
3669   int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
3670   assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check");
3671   return online_cpus;
3672 }
3673 
3674 void os::set_native_thread_name(const char *name) {
3675   // Not yet implemented.
3676   return;
3677 }
3678 
3679 bool os::distribute_processes(uint length, uint* distribution) {
3680   // Not yet implemented.
3681   return false;
3682 }
3683 
3684 bool os::bind_to_processor(uint processor_id) {
3685   // Not yet implemented.
3686   return false;
3687 }
3688 
3689 void os::SuspendedThreadTask::internal_do_task() {
3690   if (do_suspend(_thread->osthread())) {
3691     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3692     do_task(context);
3693     do_resume(_thread->osthread());
3694   }
3695 }
3696 
3697 ////////////////////////////////////////////////////////////////////////////////
3698 // debug support
3699 
3700 bool os::find(address addr, outputStream* st) {
3701 
3702   st->print(PTR_FORMAT ": ", addr);
3703 
3704   loaded_module_t lm;
3705   if (LoadedLibraries::find_for_text_address(addr, &lm) != NULL ||
3706       LoadedLibraries::find_for_data_address(addr, &lm) != NULL) {
3707     st->print_cr("%s", lm.path);
3708     return true;
3709   }
3710 
3711   return false;
3712 }
3713 
3714 ////////////////////////////////////////////////////////////////////////////////
3715 // misc
3716 
3717 // This does not do anything on Aix. This is basically a hook for being
3718 // able to use structured exception handling (thread-local exception filters)
3719 // on, e.g., Win32.
3720 void
3721 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
3722                          JavaCallArguments* args, Thread* thread) {
3723   f(value, method, args, thread);
3724 }
3725 
3726 void os::print_statistics() {
3727 }
3728 
3729 bool os::message_box(const char* title, const char* message) {
3730   int i;
3731   fdStream err(defaultStream::error_fd());
3732   for (i = 0; i < 78; i++) err.print_raw("=");
3733   err.cr();
3734   err.print_raw_cr(title);
3735   for (i = 0; i < 78; i++) err.print_raw("-");
3736   err.cr();
3737   err.print_raw_cr(message);
3738   for (i = 0; i < 78; i++) err.print_raw("=");
3739   err.cr();
3740 
3741   char buf[16];
3742   // Prevent process from exiting upon "read error" without consuming all CPU
3743   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3744 
3745   return buf[0] == 'y' || buf[0] == 'Y';
3746 }
3747 
3748 int os::stat(const char *path, struct stat *sbuf) {
3749   char pathbuf[MAX_PATH];
3750   if (strlen(path) > MAX_PATH - 1) {
3751     errno = ENAMETOOLONG;
3752     return -1;
3753   }
3754   os::native_path(strcpy(pathbuf, path));
3755   return ::stat(pathbuf, sbuf);
3756 }
3757 
3758 // Is a (classpath) directory empty?
3759 bool os::dir_is_empty(const char* path) {
3760   DIR *dir = NULL;
3761   struct dirent *ptr;
3762 
3763   dir = opendir(path);
3764   if (dir == NULL) return true;
3765 
3766   /* Scan the directory */
3767   bool result = true;
3768   char buf[sizeof(struct dirent) + MAX_PATH];
3769   while (result && (ptr = ::readdir(dir)) != NULL) {
3770     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3771       result = false;
3772     }
3773   }
3774   closedir(dir);
3775   return result;
3776 }
3777 
3778 // This code originates from JDK's sysOpen and open64_w
3779 // from src/solaris/hpi/src/system_md.c
3780 
3781 int os::open(const char *path, int oflag, int mode) {
3782 
3783   if (strlen(path) > MAX_PATH - 1) {
3784     errno = ENAMETOOLONG;
3785     return -1;
3786   }
3787   int fd;
3788 
3789   fd = ::open64(path, oflag, mode);
3790   if (fd == -1) return -1;
3791 
3792   // If the open succeeded, the file might still be a directory.
3793   {
3794     struct stat64 buf64;
3795     int ret = ::fstat64(fd, &buf64);
3796     int st_mode = buf64.st_mode;
3797 
3798     if (ret != -1) {
3799       if ((st_mode & S_IFMT) == S_IFDIR) {
3800         errno = EISDIR;
3801         ::close(fd);
3802         return -1;
3803       }
3804     } else {
3805       ::close(fd);
3806       return -1;
3807     }
3808   }
3809 
3810   // All file descriptors that are opened in the JVM and not
3811   // specifically destined for a subprocess should have the
3812   // close-on-exec flag set. If we don't set it, then careless 3rd
3813   // party native code might fork and exec without closing all
3814   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3815   // UNIXProcess.c), and this in turn might:
3816   //
3817   // - cause end-of-file to fail to be detected on some file
3818   //   descriptors, resulting in mysterious hangs, or
3819   //
3820   // - might cause an fopen in the subprocess to fail on a system
3821   //   suffering from bug 1085341.
3822   //
3823   // (Yes, the default setting of the close-on-exec flag is a Unix
3824   // design flaw.)
3825   //
3826   // See:
3827   // 1085341: 32-bit stdio routines should support file descriptors >255
3828   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3829   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3830 #ifdef FD_CLOEXEC
3831   {
3832     int flags = ::fcntl(fd, F_GETFD);
3833     if (flags != -1)
3834       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3835   }
3836 #endif
3837 
3838   return fd;
3839 }
3840 
3841 // create binary file, rewriting existing file if required
3842 int os::create_binary_file(const char* path, bool rewrite_existing) {
3843   int oflags = O_WRONLY | O_CREAT;
3844   if (!rewrite_existing) {
3845     oflags |= O_EXCL;
3846   }
3847   return ::open64(path, oflags, S_IREAD | S_IWRITE);
3848 }
3849 
3850 // return current position of file pointer
3851 jlong os::current_file_offset(int fd) {
3852   return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
3853 }
3854 
3855 // move file pointer to the specified offset
3856 jlong os::seek_to_file_offset(int fd, jlong offset) {
3857   return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
3858 }
3859 
3860 // This code originates from JDK's sysAvailable
3861 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3862 
3863 int os::available(int fd, jlong *bytes) {
3864   jlong cur, end;
3865   int mode;
3866   struct stat64 buf64;
3867 
3868   if (::fstat64(fd, &buf64) >= 0) {
3869     mode = buf64.st_mode;
3870     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3871       int n;
3872       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3873         *bytes = n;
3874         return 1;
3875       }
3876     }
3877   }
3878   if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
3879     return 0;
3880   } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
3881     return 0;
3882   } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
3883     return 0;
3884   }
3885   *bytes = end - cur;
3886   return 1;
3887 }
3888 
3889 // Map a block of memory.
3890 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3891                         char *addr, size_t bytes, bool read_only,
3892                         bool allow_exec) {
3893   int prot;
3894   int flags = MAP_PRIVATE;
3895 
3896   if (read_only) {
3897     prot = PROT_READ;
3898     flags = MAP_SHARED;
3899   } else {
3900     prot = PROT_READ | PROT_WRITE;
3901     flags = MAP_PRIVATE;
3902   }
3903 
3904   if (allow_exec) {
3905     prot |= PROT_EXEC;
3906   }
3907 
3908   if (addr != NULL) {
3909     flags |= MAP_FIXED;
3910   }
3911 
3912   // Allow anonymous mappings if 'fd' is -1.
3913   if (fd == -1) {
3914     flags |= MAP_ANONYMOUS;
3915   }
3916 
3917   char* mapped_address = (char*)::mmap(addr, (size_t)bytes, prot, flags,
3918                                      fd, file_offset);
3919   if (mapped_address == MAP_FAILED) {
3920     return NULL;
3921   }
3922   return mapped_address;
3923 }
3924 
3925 // Remap a block of memory.
3926 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3927                           char *addr, size_t bytes, bool read_only,
3928                           bool allow_exec) {
3929   // same as map_memory() on this OS
3930   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3931                         allow_exec);
3932 }
3933 
3934 // Unmap a block of memory.
3935 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3936   return munmap(addr, bytes) == 0;
3937 }
3938 
3939 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3940 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3941 // of a thread.
3942 //
3943 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3944 // the fast estimate available on the platform.
3945 
3946 jlong os::current_thread_cpu_time() {
3947   // return user + sys since the cost is the same
3948   const jlong n = os::thread_cpu_time(Thread::current(), true /* user + sys */);
3949   assert(n >= 0, "negative CPU time");
3950   return n;
3951 }
3952 
3953 jlong os::thread_cpu_time(Thread* thread) {
3954   // consistent with what current_thread_cpu_time() returns
3955   const jlong n = os::thread_cpu_time(thread, true /* user + sys */);
3956   assert(n >= 0, "negative CPU time");
3957   return n;
3958 }
3959 
3960 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3961   const jlong n = os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3962   assert(n >= 0, "negative CPU time");
3963   return n;
3964 }
3965 
3966 static bool thread_cpu_time_unchecked(Thread* thread, jlong* p_sys_time, jlong* p_user_time) {
3967   bool error = false;
3968 
3969   jlong sys_time = 0;
3970   jlong user_time = 0;
3971 
3972   // Reimplemented using getthrds64().
3973   //
3974   // Works like this:
3975   // For the thread in question, get the kernel thread id. Then get the
3976   // kernel thread statistics using that id.
3977   //
3978   // This only works of course when no pthread scheduling is used,
3979   // i.e. there is a 1:1 relationship to kernel threads.
3980   // On AIX, see AIXTHREAD_SCOPE variable.
3981 
3982   pthread_t pthtid = thread->osthread()->pthread_id();
3983 
3984   // retrieve kernel thread id for the pthread:
3985   tid64_t tid = 0;
3986   struct __pthrdsinfo pinfo;
3987   // I just love those otherworldly IBM APIs which force me to hand down
3988   // dummy buffers for stuff I dont care for...
3989   char dummy[1];
3990   int dummy_size = sizeof(dummy);
3991   if (pthread_getthrds_np(&pthtid, PTHRDSINFO_QUERY_TID, &pinfo, sizeof(pinfo),
3992                           dummy, &dummy_size) == 0) {
3993     tid = pinfo.__pi_tid;
3994   } else {
3995     tty->print_cr("pthread_getthrds_np failed.");
3996     error = true;
3997   }
3998 
3999   // retrieve kernel timing info for that kernel thread
4000   if (!error) {
4001     struct thrdentry64 thrdentry;
4002     if (getthrds64(getpid(), &thrdentry, sizeof(thrdentry), &tid, 1) == 1) {
4003       sys_time = thrdentry.ti_ru.ru_stime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_stime.tv_usec * 1000LL;
4004       user_time = thrdentry.ti_ru.ru_utime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_utime.tv_usec * 1000LL;
4005     } else {
4006       tty->print_cr("pthread_getthrds_np failed.");
4007       error = true;
4008     }
4009   }
4010 
4011   if (p_sys_time) {
4012     *p_sys_time = sys_time;
4013   }
4014 
4015   if (p_user_time) {
4016     *p_user_time = user_time;
4017   }
4018 
4019   if (error) {
4020     return false;
4021   }
4022 
4023   return true;
4024 }
4025 
4026 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4027   jlong sys_time;
4028   jlong user_time;
4029 
4030   if (!thread_cpu_time_unchecked(thread, &sys_time, &user_time)) {
4031     return -1;
4032   }
4033 
4034   return user_sys_cpu_time ? sys_time + user_time : user_time;
4035 }
4036 
4037 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4038   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4039   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4040   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4041   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4042 }
4043 
4044 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4045   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4046   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4047   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4048   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4049 }
4050 
4051 bool os::is_thread_cpu_time_supported() {
4052   return true;
4053 }
4054 
4055 // System loadavg support. Returns -1 if load average cannot be obtained.
4056 // For now just return the system wide load average (no processor sets).
4057 int os::loadavg(double values[], int nelem) {
4058 
4059   guarantee(nelem >= 0 && nelem <= 3, "argument error");
4060   guarantee(values, "argument error");
4061 
4062   if (os::Aix::on_pase()) {
4063 
4064     // AS/400 PASE: use libo4 porting library
4065     double v[3] = { 0.0, 0.0, 0.0 };
4066 
4067     if (libo4::get_load_avg(v, v + 1, v + 2)) {
4068       for (int i = 0; i < nelem; i ++) {
4069         values[i] = v[i];
4070       }
4071       return nelem;
4072     } else {
4073       return -1;
4074     }
4075 
4076   } else {
4077 
4078     // AIX: use libperfstat
4079     libperfstat::cpuinfo_t ci;
4080     if (libperfstat::get_cpuinfo(&ci)) {
4081       for (int i = 0; i < nelem; i++) {
4082         values[i] = ci.loadavg[i];
4083       }
4084     } else {
4085       return -1;
4086     }
4087     return nelem;
4088   }
4089 }
4090 
4091 void os::pause() {
4092   char filename[MAX_PATH];
4093   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4094     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4095   } else {
4096     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4097   }
4098 
4099   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4100   if (fd != -1) {
4101     struct stat buf;
4102     ::close(fd);
4103     while (::stat(filename, &buf) == 0) {
4104       (void)::poll(NULL, 0, 100);
4105     }
4106   } else {
4107     trcVerbose("Could not open pause file '%s', continuing immediately.", filename);
4108   }
4109 }
4110 
4111 bool os::is_primordial_thread(void) {
4112   if (pthread_self() == (pthread_t)1) {
4113     return true;
4114   } else {
4115     return false;
4116   }
4117 }
4118 
4119 // OS recognitions (PASE/AIX, OS level) call this before calling any
4120 // one of Aix::on_pase(), Aix::os_version() static
4121 void os::Aix::initialize_os_info() {
4122 
4123   assert(_on_pase == -1 && _os_version == 0, "already called.");
4124 
4125   struct utsname uts;
4126   memset(&uts, 0, sizeof(uts));
4127   strcpy(uts.sysname, "?");
4128   if (::uname(&uts) == -1) {
4129     trcVerbose("uname failed (%d)", errno);
4130     guarantee(0, "Could not determine whether we run on AIX or PASE");
4131   } else {
4132     trcVerbose("uname says: sysname \"%s\" version \"%s\" release \"%s\" "
4133                "node \"%s\" machine \"%s\"\n",
4134                uts.sysname, uts.version, uts.release, uts.nodename, uts.machine);
4135     const int major = atoi(uts.version);
4136     assert(major > 0, "invalid OS version");
4137     const int minor = atoi(uts.release);
4138     assert(minor > 0, "invalid OS release");
4139     _os_version = (major << 24) | (minor << 16);
4140     char ver_str[20] = {0};
4141     char *name_str = "unknown OS";
4142     if (strcmp(uts.sysname, "OS400") == 0) {
4143       // We run on AS/400 PASE. We do not support versions older than V5R4M0.
4144       _on_pase = 1;
4145       if (os_version_short() < 0x0504) {
4146         trcVerbose("OS/400 releases older than V5R4M0 not supported.");
4147         assert(false, "OS/400 release too old.");
4148       }
4149       name_str = "OS/400 (pase)";
4150       jio_snprintf(ver_str, sizeof(ver_str), "%u.%u", major, minor);
4151     } else if (strcmp(uts.sysname, "AIX") == 0) {
4152       // We run on AIX. We do not support versions older than AIX 5.3.
4153       _on_pase = 0;
4154       // Determine detailed AIX version: Version, Release, Modification, Fix Level.
4155       odmWrapper::determine_os_kernel_version(&_os_version);
4156       if (os_version_short() < 0x0503) {
4157         trcVerbose("AIX release older than AIX 5.3 not supported.");
4158         assert(false, "AIX release too old.");
4159       }
4160       name_str = "AIX";
4161       jio_snprintf(ver_str, sizeof(ver_str), "%u.%u.%u.%u",
4162                    major, minor, (_os_version >> 8) & 0xFF, _os_version & 0xFF);
4163     } else {
4164       assert(false, name_str);
4165     }
4166     trcVerbose("We run on %s %s", name_str, ver_str);
4167   }
4168 
4169   guarantee(_on_pase != -1 && _os_version, "Could not determine AIX/OS400 release");
4170 } // end: os::Aix::initialize_os_info()
4171 
4172 // Scan environment for important settings which might effect the VM.
4173 // Trace out settings. Warn about invalid settings and/or correct them.
4174 //
4175 // Must run after os::Aix::initialue_os_info().
4176 void os::Aix::scan_environment() {
4177 
4178   char* p;
4179   int rc;
4180 
4181   // Warn explicity if EXTSHM=ON is used. That switch changes how
4182   // System V shared memory behaves. One effect is that page size of
4183   // shared memory cannot be change dynamically, effectivly preventing
4184   // large pages from working.
4185   // This switch was needed on AIX 32bit, but on AIX 64bit the general
4186   // recommendation is (in OSS notes) to switch it off.
4187   p = ::getenv("EXTSHM");
4188   trcVerbose("EXTSHM=%s.", p ? p : "<unset>");
4189   if (p && strcasecmp(p, "ON") == 0) {
4190     _extshm = 1;
4191     trcVerbose("*** Unsupported mode! Please remove EXTSHM from your environment! ***");
4192     if (!AllowExtshm) {
4193       // We allow under certain conditions the user to continue. However, we want this
4194       // to be a fatal error by default. On certain AIX systems, leaving EXTSHM=ON means
4195       // that the VM is not able to allocate 64k pages for the heap.
4196       // We do not want to run with reduced performance.
4197       vm_exit_during_initialization("EXTSHM is ON. Please remove EXTSHM from your environment.");
4198     }
4199   } else {
4200     _extshm = 0;
4201   }
4202 
4203   // SPEC1170 behaviour: will change the behaviour of a number of POSIX APIs.
4204   // Not tested, not supported.
4205   //
4206   // Note that it might be worth the trouble to test and to require it, if only to
4207   // get useful return codes for mprotect.
4208   //
4209   // Note: Setting XPG_SUS_ENV in the process is too late. Must be set earlier (before
4210   // exec() ? before loading the libjvm ? ....)
4211   p = ::getenv("XPG_SUS_ENV");
4212   trcVerbose("XPG_SUS_ENV=%s.", p ? p : "<unset>");
4213   if (p && strcmp(p, "ON") == 0) {
4214     _xpg_sus_mode = 1;
4215     trcVerbose("Unsupported setting: XPG_SUS_ENV=ON");
4216     // This is not supported. Worst of all, it changes behaviour of mmap MAP_FIXED to
4217     // clobber address ranges. If we ever want to support that, we have to do some
4218     // testing first.
4219     guarantee(false, "XPG_SUS_ENV=ON not supported");
4220   } else {
4221     _xpg_sus_mode = 0;
4222   }
4223 
4224   if (os::Aix::on_pase()) {
4225     p = ::getenv("QIBM_MULTI_THREADED");
4226     trcVerbose("QIBM_MULTI_THREADED=%s.", p ? p : "<unset>");
4227   }
4228 
4229   p = ::getenv("LDR_CNTRL");
4230   trcVerbose("LDR_CNTRL=%s.", p ? p : "<unset>");
4231   if (os::Aix::on_pase() && os::Aix::os_version_short() == 0x0701) {
4232     if (p && ::strstr(p, "TEXTPSIZE")) {
4233       trcVerbose("*** WARNING - LDR_CNTRL contains TEXTPSIZE. "
4234         "you may experience hangs or crashes on OS/400 V7R1.");
4235     }
4236   }
4237 
4238   p = ::getenv("AIXTHREAD_GUARDPAGES");
4239   trcVerbose("AIXTHREAD_GUARDPAGES=%s.", p ? p : "<unset>");
4240 
4241 } // end: os::Aix::scan_environment()
4242 
4243 // PASE: initialize the libo4 library (PASE porting library).
4244 void os::Aix::initialize_libo4() {
4245   guarantee(os::Aix::on_pase(), "OS/400 only.");
4246   if (!libo4::init()) {
4247     trcVerbose("libo4 initialization failed.");
4248     assert(false, "libo4 initialization failed");
4249   } else {
4250     trcVerbose("libo4 initialized.");
4251   }
4252 }
4253 
4254 // AIX: initialize the libperfstat library.
4255 void os::Aix::initialize_libperfstat() {
4256   assert(os::Aix::on_aix(), "AIX only");
4257   if (!libperfstat::init()) {
4258     trcVerbose("libperfstat initialization failed.");
4259     assert(false, "libperfstat initialization failed");
4260   } else {
4261     trcVerbose("libperfstat initialized.");
4262   }
4263 }
4264 
4265 /////////////////////////////////////////////////////////////////////////////
4266 // thread stack
4267 
4268 // Get the current stack base from the OS (actually, the pthread library).
4269 // Note: usually not page aligned.
4270 address os::current_stack_base() {
4271   AixMisc::stackbounds_t bounds;
4272   bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
4273   guarantee(rc, "Unable to retrieve stack bounds.");
4274   return bounds.base;
4275 }
4276 
4277 // Get the current stack size from the OS (actually, the pthread library).
4278 // Returned size is such that (base - size) is always aligned to page size.
4279 size_t os::current_stack_size() {
4280   AixMisc::stackbounds_t bounds;
4281   bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
4282   guarantee(rc, "Unable to retrieve stack bounds.");
4283   // Align the returned stack size such that the stack low address
4284   // is aligned to page size (Note: base is usually not and we do not care).
4285   // We need to do this because caller code will assume stack low address is
4286   // page aligned and will place guard pages without checking.
4287   address low = bounds.base - bounds.size;
4288   address low_aligned = (address)align_up(low, os::vm_page_size());
4289   size_t s = bounds.base - low_aligned;
4290   return s;
4291 }
4292 
4293 extern char** environ;
4294 
4295 // Run the specified command in a separate process. Return its exit value,
4296 // or -1 on failure (e.g. can't fork a new process).
4297 // Unlike system(), this function can be called from signal handler. It
4298 // doesn't block SIGINT et al.
4299 int os::fork_and_exec(char* cmd) {
4300   char * argv[4] = {"sh", "-c", cmd, NULL};
4301 
4302   pid_t pid = fork();
4303 
4304   if (pid < 0) {
4305     // fork failed
4306     return -1;
4307 
4308   } else if (pid == 0) {
4309     // child process
4310 
4311     // Try to be consistent with system(), which uses "/usr/bin/sh" on AIX.
4312     execve("/usr/bin/sh", argv, environ);
4313 
4314     // execve failed
4315     _exit(-1);
4316 
4317   } else {
4318     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4319     // care about the actual exit code, for now.
4320 
4321     int status;
4322 
4323     // Wait for the child process to exit. This returns immediately if
4324     // the child has already exited. */
4325     while (waitpid(pid, &status, 0) < 0) {
4326       switch (errno) {
4327         case ECHILD: return 0;
4328         case EINTR: break;
4329         default: return -1;
4330       }
4331     }
4332 
4333     if (WIFEXITED(status)) {
4334       // The child exited normally; get its exit code.
4335       return WEXITSTATUS(status);
4336     } else if (WIFSIGNALED(status)) {
4337       // The child exited because of a signal.
4338       // The best value to return is 0x80 + signal number,
4339       // because that is what all Unix shells do, and because
4340       // it allows callers to distinguish between process exit and
4341       // process death by signal.
4342       return 0x80 + WTERMSIG(status);
4343     } else {
4344       // Unknown exit code; pass it through.
4345       return status;
4346     }
4347   }
4348   return -1;
4349 }
4350 
4351 // Get the default path to the core file
4352 // Returns the length of the string
4353 int os::get_core_path(char* buffer, size_t bufferSize) {
4354   const char* p = get_current_directory(buffer, bufferSize);
4355 
4356   if (p == NULL) {
4357     assert(p != NULL, "failed to get current directory");
4358     return 0;
4359   }
4360 
4361   jio_snprintf(buffer, bufferSize, "%s/core or core.%d",
4362                                                p, current_process_id());
4363 
4364   return strlen(buffer);
4365 }
4366 
4367 #ifndef PRODUCT
4368 void TestReserveMemorySpecial_test() {
4369   // No tests available for this platform
4370 }
4371 #endif
4372 
4373 bool os::start_debugging(char *buf, int buflen) {
4374   int len = (int)strlen(buf);
4375   char *p = &buf[len];
4376 
4377   jio_snprintf(p, buflen -len,
4378                  "\n\n"
4379                  "Do you want to debug the problem?\n\n"
4380                  "To debug, run 'dbx -a %d'; then switch to thread tid " INTX_FORMAT ", k-tid " INTX_FORMAT "\n"
4381                  "Enter 'yes' to launch dbx automatically (PATH must include dbx)\n"
4382                  "Otherwise, press RETURN to abort...",
4383                  os::current_process_id(),
4384                  os::current_thread_id(), thread_self());
4385 
4386   bool yes = os::message_box("Unexpected Error", buf);
4387 
4388   if (yes) {
4389     // yes, user asked VM to launch debugger
4390     jio_snprintf(buf, buflen, "dbx -a %d", os::current_process_id());
4391 
4392     os::fork_and_exec(buf);
4393     yes = false;
4394   }
4395   return yes;
4396 }
4397 
4398 static inline time_t get_mtime(const char* filename) {
4399   struct stat st;
4400   int ret = os::stat(filename, &st);
4401   assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
4402   return st.st_mtime;
4403 }
4404 
4405 int os::compare_file_modified_times(const char* file1, const char* file2) {
4406   time_t t1 = get_mtime(file1);
4407   time_t t2 = get_mtime(file2);
4408   return t1 - t2;
4409 }