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