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