1 /*
   2  * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2012, 2020 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 "logging/logStream.hpp"
  41 #include "libo4.hpp"
  42 #include "libperfstat_aix.hpp"
  43 #include "libodm_aix.hpp"
  44 #include "loadlib_aix.hpp"
  45 #include "memory/allocation.inline.hpp"
  46 #include "memory/filemap.hpp"
  47 #include "misc_aix.hpp"
  48 #include "oops/oop.inline.hpp"
  49 #include "os_aix.inline.hpp"
  50 #include "os_share_aix.hpp"
  51 #include "porting_aix.hpp"
  52 #include "prims/jniFastGetField.hpp"
  53 #include "prims/jvm_misc.hpp"
  54 #include "runtime/arguments.hpp"
  55 #include "runtime/atomic.hpp"
  56 #include "runtime/extendedPC.hpp"
  57 #include "runtime/globals.hpp"
  58 #include "runtime/interfaceSupport.inline.hpp"
  59 #include "runtime/java.hpp"
  60 #include "runtime/javaCalls.hpp"
  61 #include "runtime/mutexLocker.hpp"
  62 #include "runtime/objectMonitor.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_7
 135   #define PV_7 0x200000          /* Power PC 7 */
 136 #endif
 137 #ifndef PV_7_Compat
 138   #define PV_7_Compat 0x208000   /* Power PC 7 */
 139 #endif
 140 #ifndef PV_8
 141   #define PV_8 0x300000          /* Power PC 8 */
 142 #endif
 143 #ifndef PV_8_Compat
 144   #define PV_8_Compat 0x308000   /* Power PC 8 */
 145 #endif
 146 #ifndef PV_9
 147   #define PV_9 0x400000          /* Power PC 9 */
 148 #endif
 149 #ifndef PV_9_Compat
 150   #define PV_9_Compat  0x408000  /* Power PC 9 */
 151 #endif
 152 
 153 
 154 static address resolve_function_descriptor_to_code_pointer(address p);
 155 
 156 static void vmembk_print_on(outputStream* os);
 157 
 158 ////////////////////////////////////////////////////////////////////////////////
 159 // global variables (for a description see os_aix.hpp)
 160 
 161 julong    os::Aix::_physical_memory = 0;
 162 
 163 pthread_t os::Aix::_main_thread = ((pthread_t)0);
 164 int       os::Aix::_page_size = -1;
 165 
 166 // -1 = uninitialized, 0 if AIX, 1 if OS/400 pase
 167 int       os::Aix::_on_pase = -1;
 168 
 169 // 0 = uninitialized, otherwise 32 bit number:
 170 //  0xVVRRTTSS
 171 //  VV - major version
 172 //  RR - minor version
 173 //  TT - tech level, if known, 0 otherwise
 174 //  SS - service pack, if known, 0 otherwise
 175 uint32_t  os::Aix::_os_version = 0;
 176 
 177 // -1 = uninitialized, 0 - no, 1 - yes
 178 int       os::Aix::_xpg_sus_mode = -1;
 179 
 180 // -1 = uninitialized, 0 - no, 1 - yes
 181 int       os::Aix::_extshm = -1;
 182 
 183 ////////////////////////////////////////////////////////////////////////////////
 184 // local variables
 185 
 186 static volatile jlong max_real_time = 0;
 187 static jlong    initial_time_count = 0;
 188 static int      clock_tics_per_sec = 100;
 189 static sigset_t check_signal_done;         // For diagnostics to print a message once (see run_periodic_checks)
 190 static bool     check_signals      = true;
 191 static int      SR_signum          = SIGUSR2; // Signal used to suspend/resume a thread (must be > SIGSEGV, see 4355769)
 192 static sigset_t SR_sigset;
 193 
 194 // Process break recorded at startup.
 195 static address g_brk_at_startup = NULL;
 196 
 197 // This describes the state of multipage support of the underlying
 198 // OS. Note that this is of no interest to the outsize world and
 199 // therefore should not be defined in AIX class.
 200 //
 201 // AIX supports four different page sizes - 4K, 64K, 16MB, 16GB. The
 202 // latter two (16M "large" resp. 16G "huge" pages) require special
 203 // setup and are normally not available.
 204 //
 205 // AIX supports multiple page sizes per process, for:
 206 //  - Stack (of the primordial thread, so not relevant for us)
 207 //  - Data - data, bss, heap, for us also pthread stacks
 208 //  - Text - text code
 209 //  - shared memory
 210 //
 211 // Default page sizes can be set via linker options (-bdatapsize, -bstacksize, ...)
 212 // and via environment variable LDR_CNTRL (DATAPSIZE, STACKPSIZE, ...).
 213 //
 214 // For shared memory, page size can be set dynamically via
 215 // shmctl(). Different shared memory regions can have different page
 216 // sizes.
 217 //
 218 // More information can be found at AIBM info center:
 219 //   http://publib.boulder.ibm.com/infocenter/aix/v6r1/index.jsp?topic=/com.ibm.aix.prftungd/doc/prftungd/multiple_page_size_app_support.htm
 220 //
 221 static struct {
 222   size_t pagesize;            // sysconf _SC_PAGESIZE (4K)
 223   size_t datapsize;           // default data page size (LDR_CNTRL DATAPSIZE)
 224   size_t shmpsize;            // default shared memory page size (LDR_CNTRL SHMPSIZE)
 225   size_t pthr_stack_pagesize; // stack page size of pthread threads
 226   size_t textpsize;           // default text page size (LDR_CNTRL STACKPSIZE)
 227   bool can_use_64K_pages;     // True if we can alloc 64K pages dynamically with Sys V shm.
 228   bool can_use_16M_pages;     // True if we can alloc 16M pages dynamically with Sys V shm.
 229   int error;                  // Error describing if something went wrong at multipage init.
 230 } g_multipage_support = {
 231   (size_t) -1,
 232   (size_t) -1,
 233   (size_t) -1,
 234   (size_t) -1,
 235   (size_t) -1,
 236   false, false,
 237   0
 238 };
 239 
 240 // We must not accidentally allocate memory close to the BRK - even if
 241 // that would work - because then we prevent the BRK segment from
 242 // growing which may result in a malloc OOM even though there is
 243 // enough memory. The problem only arises if we shmat() or mmap() at
 244 // a specific wish address, e.g. to place the heap in a
 245 // compressed-oops-friendly way.
 246 static bool is_close_to_brk(address a) {
 247   assert0(g_brk_at_startup != NULL);
 248   if (a >= g_brk_at_startup &&
 249       a < (g_brk_at_startup + MaxExpectedDataSegmentSize)) {
 250     return true;
 251   }
 252   return false;
 253 }
 254 
 255 julong os::available_memory() {
 256   return Aix::available_memory();
 257 }
 258 
 259 julong os::Aix::available_memory() {
 260   // Avoid expensive API call here, as returned value will always be null.
 261   if (os::Aix::on_pase()) {
 262     return 0x0LL;
 263   }
 264   os::Aix::meminfo_t mi;
 265   if (os::Aix::get_meminfo(&mi)) {
 266     return mi.real_free;
 267   } else {
 268     return ULONG_MAX;
 269   }
 270 }
 271 
 272 julong os::physical_memory() {
 273   return Aix::physical_memory();
 274 }
 275 
 276 // Return true if user is running as root.
 277 
 278 bool os::have_special_privileges() {
 279   static bool init = false;
 280   static bool privileges = false;
 281   if (!init) {
 282     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 283     init = true;
 284   }
 285   return privileges;
 286 }
 287 
 288 // Helper function, emulates disclaim64 using multiple 32bit disclaims
 289 // because we cannot use disclaim64() on AS/400 and old AIX releases.
 290 static bool my_disclaim64(char* addr, size_t size) {
 291 
 292   if (size == 0) {
 293     return true;
 294   }
 295 
 296   // Maximum size 32bit disclaim() accepts. (Theoretically 4GB, but I just do not trust that.)
 297   const unsigned int maxDisclaimSize = 0x40000000;
 298 
 299   const unsigned int numFullDisclaimsNeeded = (size / maxDisclaimSize);
 300   const unsigned int lastDisclaimSize = (size % maxDisclaimSize);
 301 
 302   char* p = addr;
 303 
 304   for (int i = 0; i < numFullDisclaimsNeeded; i ++) {
 305     if (::disclaim(p, maxDisclaimSize, DISCLAIM_ZEROMEM) != 0) {
 306       trcVerbose("Cannot disclaim %p - %p (errno %d)\n", p, p + maxDisclaimSize, errno);
 307       return false;
 308     }
 309     p += maxDisclaimSize;
 310   }
 311 
 312   if (lastDisclaimSize > 0) {
 313     if (::disclaim(p, lastDisclaimSize, DISCLAIM_ZEROMEM) != 0) {
 314       trcVerbose("Cannot disclaim %p - %p (errno %d)\n", p, p + lastDisclaimSize, errno);
 315       return false;
 316     }
 317   }
 318 
 319   return true;
 320 }
 321 
 322 // Cpu architecture string
 323 #if defined(PPC32)
 324 static char cpu_arch[] = "ppc";
 325 #elif defined(PPC64)
 326 static char cpu_arch[] = "ppc64";
 327 #else
 328 #error Add appropriate cpu_arch setting
 329 #endif
 330 
 331 // Wrap the function "vmgetinfo" which is not available on older OS releases.
 332 static int checked_vmgetinfo(void *out, int command, int arg) {
 333   if (os::Aix::on_pase() && os::Aix::os_version_short() < 0x0601) {
 334     guarantee(false, "cannot call vmgetinfo on AS/400 older than V6R1");
 335   }
 336   return ::vmgetinfo(out, command, arg);
 337 }
 338 
 339 // Given an address, returns the size of the page backing that address.
 340 size_t os::Aix::query_pagesize(void* addr) {
 341 
 342   if (os::Aix::on_pase() && os::Aix::os_version_short() < 0x0601) {
 343     // AS/400 older than V6R1: no vmgetinfo here, default to 4K
 344     return 4*K;
 345   }
 346 
 347   vm_page_info pi;
 348   pi.addr = (uint64_t)addr;
 349   if (checked_vmgetinfo(&pi, VM_PAGE_INFO, sizeof(pi)) == 0) {
 350     return pi.pagesize;
 351   } else {
 352     assert(false, "vmgetinfo failed to retrieve page size");
 353     return 4*K;
 354   }
 355 }
 356 
 357 void os::Aix::initialize_system_info() {
 358 
 359   // Get the number of online(logical) cpus instead of configured.
 360   os::_processor_count = sysconf(_SC_NPROCESSORS_ONLN);
 361   assert(_processor_count > 0, "_processor_count must be > 0");
 362 
 363   // Retrieve total physical storage.
 364   os::Aix::meminfo_t mi;
 365   if (!os::Aix::get_meminfo(&mi)) {
 366     assert(false, "os::Aix::get_meminfo failed.");
 367   }
 368   _physical_memory = (julong) mi.real_total;
 369 }
 370 
 371 // Helper function for tracing page sizes.
 372 static const char* describe_pagesize(size_t pagesize) {
 373   switch (pagesize) {
 374     case 4*K : return "4K";
 375     case 64*K: return "64K";
 376     case 16*M: return "16M";
 377     case 16*G: return "16G";
 378     default:
 379       assert(false, "surprise");
 380       return "??";
 381   }
 382 }
 383 
 384 // Probe OS for multipage support.
 385 // Will fill the global g_multipage_support structure.
 386 // Must be called before calling os::large_page_init().
 387 static void query_multipage_support() {
 388 
 389   guarantee(g_multipage_support.pagesize == -1,
 390             "do not call twice");
 391 
 392   g_multipage_support.pagesize = ::sysconf(_SC_PAGESIZE);
 393 
 394   // This really would surprise me.
 395   assert(g_multipage_support.pagesize == 4*K, "surprise!");
 396 
 397   // Query default data page size (default page size for C-Heap, pthread stacks and .bss).
 398   // Default data page size is defined either by linker options (-bdatapsize)
 399   // or by environment variable LDR_CNTRL (suboption DATAPSIZE). If none is given,
 400   // default should be 4K.
 401   {
 402     void* p = ::malloc(16*M);
 403     g_multipage_support.datapsize = os::Aix::query_pagesize(p);
 404     ::free(p);
 405   }
 406 
 407   // Query default shm page size (LDR_CNTRL SHMPSIZE).
 408   // Note that this is pure curiosity. We do not rely on default page size but set
 409   // our own page size after allocated.
 410   {
 411     const int shmid = ::shmget(IPC_PRIVATE, 1, IPC_CREAT | S_IRUSR | S_IWUSR);
 412     guarantee(shmid != -1, "shmget failed");
 413     void* p = ::shmat(shmid, NULL, 0);
 414     ::shmctl(shmid, IPC_RMID, NULL);
 415     guarantee(p != (void*) -1, "shmat failed");
 416     g_multipage_support.shmpsize = os::Aix::query_pagesize(p);
 417     ::shmdt(p);
 418   }
 419 
 420   // Before querying the stack page size, make sure we are not running as primordial
 421   // thread (because primordial thread's stack may have different page size than
 422   // pthread thread stacks). Running a VM on the primordial thread won't work for a
 423   // number of reasons so we may just as well guarantee it here.
 424   guarantee0(!os::is_primordial_thread());
 425 
 426   // Query pthread stack page size. Should be the same as data page size because
 427   // pthread stacks are allocated from C-Heap.
 428   {
 429     int dummy = 0;
 430     g_multipage_support.pthr_stack_pagesize = os::Aix::query_pagesize(&dummy);
 431   }
 432 
 433   // Query default text page size (LDR_CNTRL TEXTPSIZE).
 434   {
 435     address any_function =
 436       resolve_function_descriptor_to_code_pointer((address)describe_pagesize);
 437     g_multipage_support.textpsize = os::Aix::query_pagesize(any_function);
 438   }
 439 
 440   // Now probe for support of 64K pages and 16M pages.
 441 
 442   // Before OS/400 V6R1, there is no support for pages other than 4K.
 443   if (os::Aix::on_pase_V5R4_or_older()) {
 444     trcVerbose("OS/400 < V6R1 - no large page support.");
 445     g_multipage_support.error = ERROR_MP_OS_TOO_OLD;
 446     goto query_multipage_support_end;
 447   }
 448 
 449   // Now check which page sizes the OS claims it supports, and of those, which actually can be used.
 450   {
 451     const int MAX_PAGE_SIZES = 4;
 452     psize_t sizes[MAX_PAGE_SIZES];
 453     const int num_psizes = checked_vmgetinfo(sizes, VMINFO_GETPSIZES, MAX_PAGE_SIZES);
 454     if (num_psizes == -1) {
 455       trcVerbose("vmgetinfo(VMINFO_GETPSIZES) failed (errno: %d)", errno);
 456       trcVerbose("disabling multipage support.");
 457       g_multipage_support.error = ERROR_MP_VMGETINFO_FAILED;
 458       goto query_multipage_support_end;
 459     }
 460     guarantee(num_psizes > 0, "vmgetinfo(.., VMINFO_GETPSIZES, ...) failed.");
 461     assert(num_psizes <= MAX_PAGE_SIZES, "Surprise! more than 4 page sizes?");
 462     trcVerbose("vmgetinfo(.., VMINFO_GETPSIZES, ...) returns %d supported page sizes: ", num_psizes);
 463     for (int i = 0; i < num_psizes; i ++) {
 464       trcVerbose(" %s ", describe_pagesize(sizes[i]));
 465     }
 466 
 467     // Can we use 64K, 16M pages?
 468     for (int i = 0; i < num_psizes; i ++) {
 469       const size_t pagesize = sizes[i];
 470       if (pagesize != 64*K && pagesize != 16*M) {
 471         continue;
 472       }
 473       bool can_use = false;
 474       trcVerbose("Probing support for %s pages...", describe_pagesize(pagesize));
 475       const int shmid = ::shmget(IPC_PRIVATE, pagesize,
 476         IPC_CREAT | S_IRUSR | S_IWUSR);
 477       guarantee0(shmid != -1); // Should always work.
 478       // Try to set pagesize.
 479       struct shmid_ds shm_buf = { 0 };
 480       shm_buf.shm_pagesize = pagesize;
 481       if (::shmctl(shmid, SHM_PAGESIZE, &shm_buf) != 0) {
 482         const int en = errno;
 483         ::shmctl(shmid, IPC_RMID, NULL); // As early as possible!
 484         trcVerbose("shmctl(SHM_PAGESIZE) failed with errno=%d", errno);
 485       } else {
 486         // Attach and double check pageisze.
 487         void* p = ::shmat(shmid, NULL, 0);
 488         ::shmctl(shmid, IPC_RMID, NULL); // As early as possible!
 489         guarantee0(p != (void*) -1); // Should always work.
 490         const size_t real_pagesize = os::Aix::query_pagesize(p);
 491         if (real_pagesize != pagesize) {
 492           trcVerbose("real page size (" SIZE_FORMAT_HEX ") differs.", real_pagesize);
 493         } else {
 494           can_use = true;
 495         }
 496         ::shmdt(p);
 497       }
 498       trcVerbose("Can use: %s", (can_use ? "yes" : "no"));
 499       if (pagesize == 64*K) {
 500         g_multipage_support.can_use_64K_pages = can_use;
 501       } else if (pagesize == 16*M) {
 502         g_multipage_support.can_use_16M_pages = can_use;
 503       }
 504     }
 505 
 506   } // end: check which pages can be used for shared memory
 507 
 508 query_multipage_support_end:
 509 
 510   trcVerbose("base page size (sysconf _SC_PAGESIZE): %s",
 511       describe_pagesize(g_multipage_support.pagesize));
 512   trcVerbose("Data page size (C-Heap, bss, etc): %s",
 513       describe_pagesize(g_multipage_support.datapsize));
 514   trcVerbose("Text page size: %s",
 515       describe_pagesize(g_multipage_support.textpsize));
 516   trcVerbose("Thread stack page size (pthread): %s",
 517       describe_pagesize(g_multipage_support.pthr_stack_pagesize));
 518   trcVerbose("Default shared memory page size: %s",
 519       describe_pagesize(g_multipage_support.shmpsize));
 520   trcVerbose("Can use 64K pages dynamically with shared memory: %s",
 521       (g_multipage_support.can_use_64K_pages ? "yes" :"no"));
 522   trcVerbose("Can use 16M pages dynamically with shared memory: %s",
 523       (g_multipage_support.can_use_16M_pages ? "yes" :"no"));
 524   trcVerbose("Multipage error details: %d",
 525       g_multipage_support.error);
 526 
 527   // sanity checks
 528   assert0(g_multipage_support.pagesize == 4*K);
 529   assert0(g_multipage_support.datapsize == 4*K || g_multipage_support.datapsize == 64*K);
 530   assert0(g_multipage_support.textpsize == 4*K || g_multipage_support.textpsize == 64*K);
 531   assert0(g_multipage_support.pthr_stack_pagesize == g_multipage_support.datapsize);
 532   assert0(g_multipage_support.shmpsize == 4*K || g_multipage_support.shmpsize == 64*K);
 533 
 534 }
 535 
 536 void os::init_system_properties_values() {
 537 
 538 #ifndef OVERRIDE_LIBPATH
 539   #define DEFAULT_LIBPATH "/lib:/usr/lib"
 540 #else
 541   #define DEFAULT_LIBPATH OVERRIDE_LIBPATH
 542 #endif
 543 #define EXTENSIONS_DIR  "/lib/ext"
 544 
 545   // Buffer that fits several sprintfs.
 546   // Note that the space for the trailing null is provided
 547   // by the nulls included by the sizeof operator.
 548   const size_t bufsize =
 549     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 550          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR)); // extensions dir
 551   char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 552 
 553   // sysclasspath, java_home, dll_dir
 554   {
 555     char *pslash;
 556     os::jvm_path(buf, bufsize);
 557 
 558     // Found the full path to libjvm.so.
 559     // Now cut the path to <java_home>/jre if we can.
 560     pslash = strrchr(buf, '/');
 561     if (pslash != NULL) {
 562       *pslash = '\0';            // Get rid of /libjvm.so.
 563     }
 564     pslash = strrchr(buf, '/');
 565     if (pslash != NULL) {
 566       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 567     }
 568     Arguments::set_dll_dir(buf);
 569 
 570     if (pslash != NULL) {
 571       pslash = strrchr(buf, '/');
 572       if (pslash != NULL) {
 573         *pslash = '\0';        // Get rid of /lib.
 574       }
 575     }
 576     Arguments::set_java_home(buf);
 577     if (!set_boot_path('/', ':')) {
 578       vm_exit_during_initialization("Failed setting boot class path.", NULL);
 579     }
 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 = 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   thread->record_stack_base_and_size();
 778 
 779   const pthread_t pthread_id = ::pthread_self();
 780   const tid_t kernel_thread_id = ::thread_self();
 781 
 782   LogTarget(Info, os, thread) lt;
 783   if (lt.is_enabled()) {
 784     address low_address = thread->stack_end();
 785     address high_address = thread->stack_base();
 786     lt.print("Thread is alive (tid: " UINTX_FORMAT ", kernel thread id: " UINTX_FORMAT
 787              ", stack [" PTR_FORMAT " - " PTR_FORMAT " (" SIZE_FORMAT "k using %uk pages)).",
 788              os::current_thread_id(), (uintx) kernel_thread_id, low_address, high_address,
 789              (high_address - low_address) / K, os::Aix::query_pagesize(low_address) / K);
 790   }
 791 
 792   // Normally, pthread stacks on AIX live in the data segment (are allocated with malloc()
 793   // by the pthread library). In rare cases, this may not be the case, e.g. when third-party
 794   // tools hook pthread_create(). In this case, we may run into problems establishing
 795   // guard pages on those stacks, because the stacks may reside in memory which is not
 796   // protectable (shmated).
 797   if (thread->stack_base() > ::sbrk(0)) {
 798     log_warning(os, thread)("Thread stack not in data segment.");
 799   }
 800 
 801   // Try to randomize the cache line index of hot stack frames.
 802   // This helps when threads of the same stack traces evict each other's
 803   // cache lines. The threads can be either from the same JVM instance, or
 804   // from different JVM instances. The benefit is especially true for
 805   // processors with hyperthreading technology.
 806 
 807   static int counter = 0;
 808   int pid = os::current_process_id();
 809   alloca(((pid ^ counter++) & 7) * 128);
 810 
 811   thread->initialize_thread_current();
 812 
 813   OSThread* osthread = thread->osthread();
 814 
 815   // Thread_id is pthread id.
 816   osthread->set_thread_id(pthread_id);
 817 
 818   // .. but keep kernel thread id too for diagnostics
 819   osthread->set_kernel_thread_id(kernel_thread_id);
 820 
 821   // Initialize signal mask for this thread.
 822   os::Aix::hotspot_sigmask(thread);
 823 
 824   // Initialize floating point control register.
 825   os::Aix::init_thread_fpu_state();
 826 
 827   assert(osthread->get_state() == RUNNABLE, "invalid os thread state");
 828 
 829   // Call one more level start routine.
 830   thread->call_run();
 831 
 832   // Note: at this point the thread object may already have deleted itself.
 833   // Prevent dereferencing it from here on out.
 834   thread = NULL;
 835 
 836   log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", kernel thread id: " UINTX_FORMAT ").",
 837     os::current_thread_id(), (uintx) kernel_thread_id);
 838 
 839   return 0;
 840 }
 841 
 842 bool os::create_thread(Thread* thread, ThreadType thr_type,
 843                        size_t req_stack_size) {
 844 
 845   assert(thread->osthread() == NULL, "caller responsible");
 846 
 847   // Allocate the OSThread object.
 848   OSThread* osthread = new OSThread(NULL, NULL);
 849   if (osthread == NULL) {
 850     return false;
 851   }
 852 
 853   // Set the correct thread state.
 854   osthread->set_thread_type(thr_type);
 855 
 856   // Initial state is ALLOCATED but not INITIALIZED
 857   osthread->set_state(ALLOCATED);
 858 
 859   thread->set_osthread(osthread);
 860 
 861   // Init thread attributes.
 862   pthread_attr_t attr;
 863   pthread_attr_init(&attr);
 864   guarantee(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) == 0, "???");
 865 
 866   // Make sure we run in 1:1 kernel-user-thread mode.
 867   if (os::Aix::on_aix()) {
 868     guarantee(pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM) == 0, "???");
 869     guarantee(pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED) == 0, "???");
 870   }
 871 
 872   // Start in suspended state, and in os::thread_start, wake the thread up.
 873   guarantee(pthread_attr_setsuspendstate_np(&attr, PTHREAD_CREATE_SUSPENDED_NP) == 0, "???");
 874 
 875   // Calculate stack size if it's not specified by caller.
 876   size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
 877 
 878   // JDK-8187028: It was observed that on some configurations (4K backed thread stacks)
 879   // the real thread stack size may be smaller than the requested stack size, by as much as 64K.
 880   // This very much looks like a pthread lib error. As a workaround, increase the stack size
 881   // by 64K for small thread stacks (arbitrarily choosen to be < 4MB)
 882   if (stack_size < 4096 * K) {
 883     stack_size += 64 * K;
 884   }
 885 
 886   // On Aix, pthread_attr_setstacksize fails with huge values and leaves the
 887   // thread size in attr unchanged. If this is the minimal stack size as set
 888   // by pthread_attr_init this leads to crashes after thread creation. E.g. the
 889   // guard pages might not fit on the tiny stack created.
 890   int ret = pthread_attr_setstacksize(&attr, stack_size);
 891   if (ret != 0) {
 892     log_warning(os, thread)("The %sthread stack size specified is invalid: " SIZE_FORMAT "k",
 893                             (thr_type == compiler_thread) ? "compiler " : ((thr_type == java_thread) ? "" : "VM "),
 894                             stack_size / K);
 895     thread->set_osthread(NULL);
 896     delete osthread;
 897     return false;
 898   }
 899 
 900   // Save some cycles and a page by disabling OS guard pages where we have our own
 901   // VM guard pages (in java threads). For other threads, keep system default guard
 902   // pages in place.
 903   if (thr_type == java_thread || thr_type == compiler_thread) {
 904     ret = pthread_attr_setguardsize(&attr, 0);
 905   }
 906 
 907   pthread_t tid = 0;
 908   if (ret == 0) {
 909     ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
 910   }
 911 
 912   if (ret == 0) {
 913     char buf[64];
 914     log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
 915       (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 916   } else {
 917     char buf[64];
 918     log_warning(os, thread)("Failed to start thread - pthread_create failed (%d=%s) for attributes: %s.",
 919       ret, os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 920     // Log some OS information which might explain why creating the thread failed.
 921     log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
 922     LogStream st(Log(os, thread)::info());
 923     os::Posix::print_rlimit_info(&st);
 924     os::print_memory_info(&st);
 925   }
 926 
 927   pthread_attr_destroy(&attr);
 928 
 929   if (ret != 0) {
 930     // Need to clean up stuff we've allocated so far.
 931     thread->set_osthread(NULL);
 932     delete osthread;
 933     return false;
 934   }
 935 
 936   // OSThread::thread_id is the pthread id.
 937   osthread->set_thread_id(tid);
 938 
 939   return true;
 940 }
 941 
 942 /////////////////////////////////////////////////////////////////////////////
 943 // attach existing thread
 944 
 945 // bootstrap the main thread
 946 bool os::create_main_thread(JavaThread* thread) {
 947   assert(os::Aix::_main_thread == pthread_self(), "should be called inside main thread");
 948   return create_attached_thread(thread);
 949 }
 950 
 951 bool os::create_attached_thread(JavaThread* thread) {
 952 #ifdef ASSERT
 953     thread->verify_not_published();
 954 #endif
 955 
 956   // Allocate the OSThread object
 957   OSThread* osthread = new OSThread(NULL, NULL);
 958 
 959   if (osthread == NULL) {
 960     return false;
 961   }
 962 
 963   const pthread_t pthread_id = ::pthread_self();
 964   const tid_t kernel_thread_id = ::thread_self();
 965 
 966   // OSThread::thread_id is the pthread id.
 967   osthread->set_thread_id(pthread_id);
 968 
 969   // .. but keep kernel thread id too for diagnostics
 970   osthread->set_kernel_thread_id(kernel_thread_id);
 971 
 972   // initialize floating point control register
 973   os::Aix::init_thread_fpu_state();
 974 
 975   // Initial thread state is RUNNABLE
 976   osthread->set_state(RUNNABLE);
 977 
 978   thread->set_osthread(osthread);
 979 
 980   if (UseNUMA) {
 981     int lgrp_id = os::numa_get_group_id();
 982     if (lgrp_id != -1) {
 983       thread->set_lgrp_id(lgrp_id);
 984     }
 985   }
 986 
 987   // initialize signal mask for this thread
 988   // and save the caller's signal mask
 989   os::Aix::hotspot_sigmask(thread);
 990 
 991   log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", kernel thread id: " UINTX_FORMAT ").",
 992     os::current_thread_id(), (uintx) kernel_thread_id);
 993 
 994   return true;
 995 }
 996 
 997 void os::pd_start_thread(Thread* thread) {
 998   int status = pthread_continue_np(thread->osthread()->pthread_id());
 999   assert(status == 0, "thr_continue failed");
1000 }
1001 
1002 // Free OS resources related to the OSThread
1003 void os::free_thread(OSThread* osthread) {
1004   assert(osthread != NULL, "osthread not set");
1005 
1006   // We are told to free resources of the argument thread,
1007   // but we can only really operate on the current thread.
1008   assert(Thread::current()->osthread() == osthread,
1009          "os::free_thread but not current thread");
1010 
1011   // Restore caller's signal mask
1012   sigset_t sigmask = osthread->caller_sigmask();
1013   pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
1014 
1015   delete osthread;
1016 }
1017 
1018 ////////////////////////////////////////////////////////////////////////////////
1019 // time support
1020 
1021 // Time since start-up in seconds to a fine granularity.
1022 // Used by VMSelfDestructTimer and the MemProfiler.
1023 double os::elapsedTime() {
1024   return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution
1025 }
1026 
1027 jlong os::elapsed_counter() {
1028   return javaTimeNanos() - initial_time_count;
1029 }
1030 
1031 jlong os::elapsed_frequency() {
1032   return NANOSECS_PER_SEC; // nanosecond resolution
1033 }
1034 
1035 bool os::supports_vtime() { return true; }
1036 
1037 double os::elapsedVTime() {
1038   struct rusage usage;
1039   int retval = getrusage(RUSAGE_THREAD, &usage);
1040   if (retval == 0) {
1041     return usage.ru_utime.tv_sec + usage.ru_stime.tv_sec + (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000.0 * 1000);
1042   } else {
1043     // better than nothing, but not much
1044     return elapsedTime();
1045   }
1046 }
1047 
1048 jlong os::javaTimeMillis() {
1049   timeval time;
1050   int status = gettimeofday(&time, NULL);
1051   assert(status != -1, "aix error at gettimeofday()");
1052   return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
1053 }
1054 
1055 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
1056   timeval time;
1057   int status = gettimeofday(&time, NULL);
1058   assert(status != -1, "aix error at gettimeofday()");
1059   seconds = jlong(time.tv_sec);
1060   nanos = jlong(time.tv_usec) * 1000;
1061 }
1062 
1063 // We use mread_real_time here.
1064 // On AIX: If the CPU has a time register, the result will be RTC_POWER and
1065 // it has to be converted to real time. AIX documentations suggests to do
1066 // this unconditionally, so we do it.
1067 //
1068 // See: https://www.ibm.com/support/knowledgecenter/ssw_aix_61/com.ibm.aix.basetrf2/read_real_time.htm
1069 //
1070 // On PASE: mread_real_time will always return RTC_POWER_PC data, so no
1071 // conversion is necessary. However, mread_real_time will not return
1072 // monotonic results but merely matches read_real_time. So we need a tweak
1073 // to ensure monotonic results.
1074 //
1075 // For PASE no public documentation exists, just word by IBM
1076 jlong os::javaTimeNanos() {
1077   timebasestruct_t time;
1078   int rc = mread_real_time(&time, TIMEBASE_SZ);
1079   if (os::Aix::on_pase()) {
1080     assert(rc == RTC_POWER, "expected time format RTC_POWER from mread_real_time in PASE");
1081     jlong now = jlong(time.tb_high) * NANOSECS_PER_SEC + jlong(time.tb_low);
1082     jlong prev = max_real_time;
1083     if (now <= prev) {
1084       return prev;   // same or retrograde time;
1085     }
1086     jlong obsv = Atomic::cmpxchg(&max_real_time, prev, now);
1087     assert(obsv >= prev, "invariant");   // Monotonicity
1088     // If the CAS succeeded then we're done and return "now".
1089     // If the CAS failed and the observed value "obsv" is >= now then
1090     // we should return "obsv".  If the CAS failed and now > obsv > prv then
1091     // some other thread raced this thread and installed a new value, in which case
1092     // we could either (a) retry the entire operation, (b) retry trying to install now
1093     // or (c) just return obsv.  We use (c).   No loop is required although in some cases
1094     // we might discard a higher "now" value in deference to a slightly lower but freshly
1095     // installed obsv value.   That's entirely benign -- it admits no new orderings compared
1096     // to (a) or (b) -- and greatly reduces coherence traffic.
1097     // We might also condition (c) on the magnitude of the delta between obsv and now.
1098     // Avoiding excessive CAS operations to hot RW locations is critical.
1099     // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1100     return (prev == obsv) ? now : obsv;
1101   } else {
1102     if (rc != RTC_POWER) {
1103       rc = time_base_to_time(&time, TIMEBASE_SZ);
1104       assert(rc != -1, "error calling time_base_to_time()");
1105     }
1106     return jlong(time.tb_high) * NANOSECS_PER_SEC + jlong(time.tb_low);
1107   }
1108 }
1109 
1110 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1111   info_ptr->max_value = ALL_64_BITS;
1112   // mread_real_time() is monotonic (see 'os::javaTimeNanos()')
1113   info_ptr->may_skip_backward = false;
1114   info_ptr->may_skip_forward = false;
1115   info_ptr->kind = JVMTI_TIMER_ELAPSED;    // elapsed not CPU time
1116 }
1117 
1118 // Return the real, user, and system times in seconds from an
1119 // arbitrary fixed point in the past.
1120 bool os::getTimesSecs(double* process_real_time,
1121                       double* process_user_time,
1122                       double* process_system_time) {
1123   struct tms ticks;
1124   clock_t real_ticks = times(&ticks);
1125 
1126   if (real_ticks == (clock_t) (-1)) {
1127     return false;
1128   } else {
1129     double ticks_per_second = (double) clock_tics_per_sec;
1130     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1131     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1132     *process_real_time = ((double) real_ticks) / ticks_per_second;
1133 
1134     return true;
1135   }
1136 }
1137 
1138 char * os::local_time_string(char *buf, size_t buflen) {
1139   struct tm t;
1140   time_t long_time;
1141   time(&long_time);
1142   localtime_r(&long_time, &t);
1143   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1144                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1145                t.tm_hour, t.tm_min, t.tm_sec);
1146   return buf;
1147 }
1148 
1149 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1150   return localtime_r(clock, res);
1151 }
1152 
1153 ////////////////////////////////////////////////////////////////////////////////
1154 // runtime exit support
1155 
1156 // Note: os::shutdown() might be called very early during initialization, or
1157 // called from signal handler. Before adding something to os::shutdown(), make
1158 // sure it is async-safe and can handle partially initialized VM.
1159 void os::shutdown() {
1160 
1161   // allow PerfMemory to attempt cleanup of any persistent resources
1162   perfMemory_exit();
1163 
1164   // needs to remove object in file system
1165   AttachListener::abort();
1166 
1167   // flush buffered output, finish log files
1168   ostream_abort();
1169 
1170   // Check for abort hook
1171   abort_hook_t abort_hook = Arguments::abort_hook();
1172   if (abort_hook != NULL) {
1173     abort_hook();
1174   }
1175 }
1176 
1177 // Note: os::abort() might be called very early during initialization, or
1178 // called from signal handler. Before adding something to os::abort(), make
1179 // sure it is async-safe and can handle partially initialized VM.
1180 void os::abort(bool dump_core, void* siginfo, const void* context) {
1181   os::shutdown();
1182   if (dump_core) {
1183 #ifndef PRODUCT
1184     fdStream out(defaultStream::output_fd());
1185     out.print_raw("Current thread is ");
1186     char buf[16];
1187     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1188     out.print_raw_cr(buf);
1189     out.print_raw_cr("Dumping core ...");
1190 #endif
1191     ::abort(); // dump core
1192   }
1193 
1194   ::exit(1);
1195 }
1196 
1197 // Die immediately, no exit hook, no abort hook, no cleanup.
1198 // Dump a core file, if possible, for debugging.
1199 void os::die() {
1200   if (TestUnresponsiveErrorHandler && !CreateCoredumpOnCrash) {
1201     // For TimeoutInErrorHandlingTest.java, we just kill the VM
1202     // and don't take the time to generate a core file.
1203     os::signal_raise(SIGKILL);
1204   } else {
1205     ::abort();
1206   }
1207 }
1208 
1209 intx os::current_thread_id() {
1210   return (intx)pthread_self();
1211 }
1212 
1213 int os::current_process_id() {
1214   return getpid();
1215 }
1216 
1217 // DLL functions
1218 
1219 const char* os::dll_file_extension() { return ".so"; }
1220 
1221 // This must be hard coded because it's the system's temporary
1222 // directory not the java application's temp directory, ala java.io.tmpdir.
1223 const char* os::get_temp_directory() { return "/tmp"; }
1224 
1225 // Check if addr is inside libjvm.so.
1226 bool os::address_is_in_vm(address addr) {
1227 
1228   // Input could be a real pc or a function pointer literal. The latter
1229   // would be a function descriptor residing in the data segment of a module.
1230   loaded_module_t lm;
1231   if (LoadedLibraries::find_for_text_address(addr, &lm) != NULL) {
1232     return lm.is_in_vm;
1233   } else if (LoadedLibraries::find_for_data_address(addr, &lm) != NULL) {
1234     return lm.is_in_vm;
1235   } else {
1236     return false;
1237   }
1238 
1239 }
1240 
1241 // Resolve an AIX function descriptor literal to a code pointer.
1242 // If the input is a valid code pointer to a text segment of a loaded module,
1243 //   it is returned unchanged.
1244 // If the input is a valid AIX function descriptor, it is resolved to the
1245 //   code entry point.
1246 // If the input is neither a valid function descriptor nor a valid code pointer,
1247 //   NULL is returned.
1248 static address resolve_function_descriptor_to_code_pointer(address p) {
1249 
1250   if (LoadedLibraries::find_for_text_address(p, NULL) != NULL) {
1251     // It is a real code pointer.
1252     return p;
1253   } else if (LoadedLibraries::find_for_data_address(p, NULL) != NULL) {
1254     // Pointer to data segment, potential function descriptor.
1255     address code_entry = (address)(((FunctionDescriptor*)p)->entry());
1256     if (LoadedLibraries::find_for_text_address(code_entry, NULL) != NULL) {
1257       // It is a function descriptor.
1258       return code_entry;
1259     }
1260   }
1261 
1262   return NULL;
1263 }
1264 
1265 bool os::dll_address_to_function_name(address addr, char *buf,
1266                                       int buflen, int *offset,
1267                                       bool demangle) {
1268   if (offset) {
1269     *offset = -1;
1270   }
1271   // Buf is not optional, but offset is optional.
1272   assert(buf != NULL, "sanity check");
1273   buf[0] = '\0';
1274 
1275   // Resolve function ptr literals first.
1276   addr = resolve_function_descriptor_to_code_pointer(addr);
1277   if (!addr) {
1278     return false;
1279   }
1280 
1281   return AixSymbols::get_function_name(addr, buf, buflen, offset, NULL, demangle);
1282 }
1283 
1284 bool os::dll_address_to_library_name(address addr, char* buf,
1285                                      int buflen, int* offset) {
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_module_name(addr, buf, buflen);
1300 }
1301 
1302 // Loads .dll/.so and in case of error it checks if .dll/.so was built
1303 // for the same architecture as Hotspot is running on.
1304 void *os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1305 
1306   log_info(os)("attempting shared library load of %s", filename);
1307 
1308   if (ebuf && ebuflen > 0) {
1309     ebuf[0] = '\0';
1310     ebuf[ebuflen - 1] = '\0';
1311   }
1312 
1313   if (!filename || strlen(filename) == 0) {
1314     ::strncpy(ebuf, "dll_load: empty filename specified", ebuflen - 1);
1315     return NULL;
1316   }
1317 
1318   // RTLD_LAZY is currently not implemented. The dl is loaded immediately with all its dependants.
1319   void * result= ::dlopen(filename, RTLD_LAZY);
1320   if (result != NULL) {
1321     Events::log(NULL, "Loaded shared library %s", filename);
1322     // Reload dll cache. Don't do this in signal handling.
1323     LoadedLibraries::reload();
1324     log_info(os)("shared library load of %s was successful", filename);
1325     return result;
1326   } else {
1327     // error analysis when dlopen fails
1328     const char* error_report = ::dlerror();
1329     if (error_report == NULL) {
1330       error_report = "dlerror returned no error description";
1331     }
1332     if (ebuf != NULL && ebuflen > 0) {
1333       snprintf(ebuf, ebuflen - 1, "%s, LIBPATH=%s, LD_LIBRARY_PATH=%s : %s",
1334                filename, ::getenv("LIBPATH"), ::getenv("LD_LIBRARY_PATH"), error_report);
1335     }
1336     Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
1337     log_info(os)("shared library load of %s failed, %s", filename, error_report);
1338   }
1339   return NULL;
1340 }
1341 
1342 void* os::dll_lookup(void* handle, const char* name) {
1343   void* res = dlsym(handle, name);
1344   return res;
1345 }
1346 
1347 void* os::get_default_process_handle() {
1348   return (void*)::dlopen(NULL, RTLD_LAZY);
1349 }
1350 
1351 void os::print_dll_info(outputStream *st) {
1352   st->print_cr("Dynamic libraries:");
1353   LoadedLibraries::print(st);
1354 }
1355 
1356 void os::get_summary_os_info(char* buf, size_t buflen) {
1357   // There might be something more readable than uname results for AIX.
1358   struct utsname name;
1359   uname(&name);
1360   snprintf(buf, buflen, "%s %s", name.release, name.version);
1361 }
1362 
1363 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1364   // Not yet implemented.
1365   return 0;
1366 }
1367 
1368 void os::print_os_info_brief(outputStream* st) {
1369   uint32_t ver = os::Aix::os_version();
1370   st->print_cr("AIX kernel version %u.%u.%u.%u",
1371                (ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
1372 
1373   os::Posix::print_uname_info(st);
1374 
1375   // Linux uses print_libversion_info(st); here.
1376 }
1377 
1378 void os::print_os_info(outputStream* st) {
1379   st->print("OS:");
1380 
1381   os::Posix::print_uname_info(st);
1382 
1383   uint32_t ver = os::Aix::os_version();
1384   st->print_cr("AIX kernel version %u.%u.%u.%u",
1385                (ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
1386 
1387   os::Posix::print_uptime_info(st);
1388 
1389   os::Posix::print_rlimit_info(st);
1390 
1391   os::Posix::print_load_average(st);
1392 
1393   // _SC_THREAD_THREADS_MAX is the maximum number of threads within a process.
1394   long tmax = sysconf(_SC_THREAD_THREADS_MAX);
1395   st->print_cr("maximum #threads within a process:%ld", tmax);
1396 
1397   // print wpar info
1398   libperfstat::wparinfo_t wi;
1399   if (libperfstat::get_wparinfo(&wi)) {
1400     st->print_cr("wpar info");
1401     st->print_cr("name: %s", wi.name);
1402     st->print_cr("id:   %d", wi.wpar_id);
1403     st->print_cr("type: %s", (wi.app_wpar ? "application" : "system"));
1404   }
1405 
1406   VM_Version::print_platform_virtualization_info(st);
1407 }
1408 
1409 void os::print_memory_info(outputStream* st) {
1410 
1411   st->print_cr("Memory:");
1412 
1413   st->print_cr("  Base page size (sysconf _SC_PAGESIZE):  %s",
1414     describe_pagesize(g_multipage_support.pagesize));
1415   st->print_cr("  Data page size (C-Heap, bss, etc):      %s",
1416     describe_pagesize(g_multipage_support.datapsize));
1417   st->print_cr("  Text page size:                         %s",
1418     describe_pagesize(g_multipage_support.textpsize));
1419   st->print_cr("  Thread stack page size (pthread):       %s",
1420     describe_pagesize(g_multipage_support.pthr_stack_pagesize));
1421   st->print_cr("  Default shared memory page size:        %s",
1422     describe_pagesize(g_multipage_support.shmpsize));
1423   st->print_cr("  Can use 64K pages dynamically with shared memory:  %s",
1424     (g_multipage_support.can_use_64K_pages ? "yes" :"no"));
1425   st->print_cr("  Can use 16M pages dynamically with shared memory: %s",
1426     (g_multipage_support.can_use_16M_pages ? "yes" :"no"));
1427   st->print_cr("  Multipage error: %d",
1428     g_multipage_support.error);
1429   st->cr();
1430   st->print_cr("  os::vm_page_size:       %s", describe_pagesize(os::vm_page_size()));
1431 
1432   // print out LDR_CNTRL because it affects the default page sizes
1433   const char* const ldr_cntrl = ::getenv("LDR_CNTRL");
1434   st->print_cr("  LDR_CNTRL=%s.", ldr_cntrl ? ldr_cntrl : "<unset>");
1435 
1436   // Print out EXTSHM because it is an unsupported setting.
1437   const char* const extshm = ::getenv("EXTSHM");
1438   st->print_cr("  EXTSHM=%s.", extshm ? extshm : "<unset>");
1439   if ( (strcmp(extshm, "on") == 0) || (strcmp(extshm, "ON") == 0) ) {
1440     st->print_cr("  *** Unsupported! Please remove EXTSHM from your environment! ***");
1441   }
1442 
1443   // Print out AIXTHREAD_GUARDPAGES because it affects the size of pthread stacks.
1444   const char* const aixthread_guardpages = ::getenv("AIXTHREAD_GUARDPAGES");
1445   st->print_cr("  AIXTHREAD_GUARDPAGES=%s.",
1446       aixthread_guardpages ? aixthread_guardpages : "<unset>");
1447   st->cr();
1448 
1449   os::Aix::meminfo_t mi;
1450   if (os::Aix::get_meminfo(&mi)) {
1451     if (os::Aix::on_aix()) {
1452       st->print_cr("physical total : " SIZE_FORMAT, mi.real_total);
1453       st->print_cr("physical free  : " SIZE_FORMAT, mi.real_free);
1454       st->print_cr("swap total     : " SIZE_FORMAT, mi.pgsp_total);
1455       st->print_cr("swap free      : " SIZE_FORMAT, mi.pgsp_free);
1456     } else {
1457       // PASE - Numbers are result of QWCRSSTS; they mean:
1458       // real_total: Sum of all system pools
1459       // real_free: always 0
1460       // pgsp_total: we take the size of the system ASP
1461       // pgsp_free: size of system ASP times percentage of system ASP unused
1462       st->print_cr("physical total     : " SIZE_FORMAT, mi.real_total);
1463       st->print_cr("system asp total   : " SIZE_FORMAT, mi.pgsp_total);
1464       st->print_cr("%% system asp used : %.2f",
1465         mi.pgsp_total ? (100.0f * (mi.pgsp_total - mi.pgsp_free) / mi.pgsp_total) : -1.0f);
1466     }
1467   }
1468   st->cr();
1469 
1470   // Print program break.
1471   st->print_cr("Program break at VM startup: " PTR_FORMAT ".", p2i(g_brk_at_startup));
1472   address brk_now = (address)::sbrk(0);
1473   if (brk_now != (address)-1) {
1474     st->print_cr("Program break now          : " PTR_FORMAT " (distance: " SIZE_FORMAT "k).",
1475                  p2i(brk_now), (size_t)((brk_now - g_brk_at_startup) / K));
1476   }
1477   st->print_cr("MaxExpectedDataSegmentSize    : " SIZE_FORMAT "k.", MaxExpectedDataSegmentSize / K);
1478   st->cr();
1479 
1480   // Print segments allocated with os::reserve_memory.
1481   st->print_cr("internal virtual memory regions used by vm:");
1482   vmembk_print_on(st);
1483 }
1484 
1485 // Get a string for the cpuinfo that is a summary of the cpu type
1486 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1487   // read _system_configuration.version
1488   switch (_system_configuration.version) {
1489   case PV_9:
1490     strncpy(buf, "Power PC 9", buflen);
1491     break;
1492   case PV_8:
1493     strncpy(buf, "Power PC 8", buflen);
1494     break;
1495   case PV_7:
1496     strncpy(buf, "Power PC 7", buflen);
1497     break;
1498   case PV_6_1:
1499     strncpy(buf, "Power PC 6 DD1.x", buflen);
1500     break;
1501   case PV_6:
1502     strncpy(buf, "Power PC 6", buflen);
1503     break;
1504   case PV_5:
1505     strncpy(buf, "Power PC 5", buflen);
1506     break;
1507   case PV_5_2:
1508     strncpy(buf, "Power PC 5_2", buflen);
1509     break;
1510   case PV_5_3:
1511     strncpy(buf, "Power PC 5_3", buflen);
1512     break;
1513   case PV_5_Compat:
1514     strncpy(buf, "PV_5_Compat", buflen);
1515     break;
1516   case PV_6_Compat:
1517     strncpy(buf, "PV_6_Compat", buflen);
1518     break;
1519   case PV_7_Compat:
1520     strncpy(buf, "PV_7_Compat", buflen);
1521     break;
1522   case PV_8_Compat:
1523     strncpy(buf, "PV_8_Compat", buflen);
1524     break;
1525   case PV_9_Compat:
1526     strncpy(buf, "PV_9_Compat", buflen);
1527     break;
1528   default:
1529     strncpy(buf, "unknown", buflen);
1530   }
1531 }
1532 
1533 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1534   // Nothing to do beyond of what os::print_cpu_info() does.
1535 }
1536 
1537 static void print_signal_handler(outputStream* st, int sig,
1538                                  char* buf, size_t buflen);
1539 
1540 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1541   st->print_cr("Signal Handlers:");
1542   print_signal_handler(st, SIGSEGV, buf, buflen);
1543   print_signal_handler(st, SIGBUS , buf, buflen);
1544   print_signal_handler(st, SIGFPE , buf, buflen);
1545   print_signal_handler(st, SIGPIPE, buf, buflen);
1546   print_signal_handler(st, SIGXFSZ, buf, buflen);
1547   print_signal_handler(st, SIGILL , buf, buflen);
1548   print_signal_handler(st, SR_signum, buf, buflen);
1549   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1550   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1551   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1552   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1553   print_signal_handler(st, SIGTRAP, buf, buflen);
1554   // We also want to know if someone else adds a SIGDANGER handler because
1555   // that will interfere with OOM killling.
1556   print_signal_handler(st, SIGDANGER, buf, buflen);
1557 }
1558 
1559 static char saved_jvm_path[MAXPATHLEN] = {0};
1560 
1561 // Find the full path to the current module, libjvm.so.
1562 void os::jvm_path(char *buf, jint buflen) {
1563   // Error checking.
1564   if (buflen < MAXPATHLEN) {
1565     assert(false, "must use a large-enough buffer");
1566     buf[0] = '\0';
1567     return;
1568   }
1569   // Lazy resolve the path to current module.
1570   if (saved_jvm_path[0] != 0) {
1571     strcpy(buf, saved_jvm_path);
1572     return;
1573   }
1574 
1575   Dl_info dlinfo;
1576   int ret = dladdr(CAST_FROM_FN_PTR(void *, os::jvm_path), &dlinfo);
1577   assert(ret != 0, "cannot locate libjvm");
1578   char* rp = os::Posix::realpath((char *)dlinfo.dli_fname, buf, buflen);
1579   assert(rp != NULL, "error in realpath(): maybe the 'path' argument is too long?");
1580 
1581   if (Arguments::sun_java_launcher_is_altjvm()) {
1582     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1583     // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
1584     // If "/jre/lib/" appears at the right place in the string, then
1585     // assume we are installed in a JDK and we're done. Otherwise, check
1586     // for a JAVA_HOME environment variable and fix up the path so it
1587     // looks like libjvm.so is installed there (append a fake suffix
1588     // hotspot/libjvm.so).
1589     const char *p = buf + strlen(buf) - 1;
1590     for (int count = 0; p > buf && count < 4; ++count) {
1591       for (--p; p > buf && *p != '/'; --p)
1592         /* empty */ ;
1593     }
1594 
1595     if (strncmp(p, "/jre/lib/", 9) != 0) {
1596       // Look for JAVA_HOME in the environment.
1597       char* java_home_var = ::getenv("JAVA_HOME");
1598       if (java_home_var != NULL && java_home_var[0] != 0) {
1599         char* jrelib_p;
1600         int len;
1601 
1602         // Check the current module name "libjvm.so".
1603         p = strrchr(buf, '/');
1604         if (p == NULL) {
1605           return;
1606         }
1607         assert(strstr(p, "/libjvm") == p, "invalid library name");
1608 
1609         rp = os::Posix::realpath(java_home_var, buf, buflen);
1610         if (rp == NULL) {
1611           return;
1612         }
1613 
1614         // determine if this is a legacy image or modules image
1615         // modules image doesn't have "jre" subdirectory
1616         len = strlen(buf);
1617         assert(len < buflen, "Ran out of buffer room");
1618         jrelib_p = buf + len;
1619         snprintf(jrelib_p, buflen-len, "/jre/lib");
1620         if (0 != access(buf, F_OK)) {
1621           snprintf(jrelib_p, buflen-len, "/lib");
1622         }
1623 
1624         if (0 == access(buf, F_OK)) {
1625           // Use current module name "libjvm.so"
1626           len = strlen(buf);
1627           snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
1628         } else {
1629           // Go back to path of .so
1630           rp = os::Posix::realpath((char *)dlinfo.dli_fname, buf, buflen);
1631           if (rp == NULL) {
1632             return;
1633           }
1634         }
1635       }
1636     }
1637   }
1638 
1639   strncpy(saved_jvm_path, buf, sizeof(saved_jvm_path));
1640   saved_jvm_path[sizeof(saved_jvm_path) - 1] = '\0';
1641 }
1642 
1643 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1644   // no prefix required, not even "_"
1645 }
1646 
1647 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1648   // no suffix required
1649 }
1650 
1651 ////////////////////////////////////////////////////////////////////////////////
1652 // sun.misc.Signal support
1653 
1654 static void
1655 UserHandler(int sig, void *siginfo, void *context) {
1656   // Ctrl-C is pressed during error reporting, likely because the error
1657   // handler fails to abort. Let VM die immediately.
1658   if (sig == SIGINT && VMError::is_error_reported()) {
1659     os::die();
1660   }
1661 
1662   os::signal_notify(sig);
1663 }
1664 
1665 void* os::user_handler() {
1666   return CAST_FROM_FN_PTR(void*, UserHandler);
1667 }
1668 
1669 extern "C" {
1670   typedef void (*sa_handler_t)(int);
1671   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1672 }
1673 
1674 void* os::signal(int signal_number, void* handler) {
1675   struct sigaction sigAct, oldSigAct;
1676 
1677   sigfillset(&(sigAct.sa_mask));
1678 
1679   // Do not block out synchronous signals in the signal handler.
1680   // Blocking synchronous signals only makes sense if you can really
1681   // be sure that those signals won't happen during signal handling,
1682   // when the blocking applies. Normal signal handlers are lean and
1683   // do not cause signals. But our signal handlers tend to be "risky"
1684   // - secondary SIGSEGV, SIGILL, SIGBUS' may and do happen.
1685   // On AIX, PASE there was a case where a SIGSEGV happened, followed
1686   // by a SIGILL, which was blocked due to the signal mask. The process
1687   // just hung forever. Better to crash from a secondary signal than to hang.
1688   sigdelset(&(sigAct.sa_mask), SIGSEGV);
1689   sigdelset(&(sigAct.sa_mask), SIGBUS);
1690   sigdelset(&(sigAct.sa_mask), SIGILL);
1691   sigdelset(&(sigAct.sa_mask), SIGFPE);
1692   sigdelset(&(sigAct.sa_mask), SIGTRAP);
1693 
1694   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1695 
1696   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1697 
1698   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1699     // -1 means registration failed
1700     return (void *)-1;
1701   }
1702 
1703   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1704 }
1705 
1706 void os::signal_raise(int signal_number) {
1707   ::raise(signal_number);
1708 }
1709 
1710 //
1711 // The following code is moved from os.cpp for making this
1712 // code platform specific, which it is by its very nature.
1713 //
1714 
1715 // Will be modified when max signal is changed to be dynamic
1716 int os::sigexitnum_pd() {
1717   return NSIG;
1718 }
1719 
1720 // a counter for each possible signal value
1721 static volatile jint pending_signals[NSIG+1] = { 0 };
1722 
1723 // Wrapper functions for: sem_init(), sem_post(), sem_wait()
1724 // On AIX, we use sem_init(), sem_post(), sem_wait()
1725 // On Pase, we need to use msem_lock() and msem_unlock(), because Posix Semaphores
1726 // do not seem to work at all on PASE (unimplemented, will cause SIGILL).
1727 // Note that just using msem_.. APIs for both PASE and AIX is not an option either, as
1728 // on AIX, msem_..() calls are suspected of causing problems.
1729 static sem_t sig_sem;
1730 static msemaphore* p_sig_msem = 0;
1731 
1732 static void local_sem_init() {
1733   if (os::Aix::on_aix()) {
1734     int rc = ::sem_init(&sig_sem, 0, 0);
1735     guarantee(rc != -1, "sem_init failed");
1736   } else {
1737     // Memory semaphores must live in shared mem.
1738     guarantee0(p_sig_msem == NULL);
1739     p_sig_msem = (msemaphore*)os::reserve_memory(sizeof(msemaphore), NULL);
1740     guarantee(p_sig_msem, "Cannot allocate memory for memory semaphore");
1741     guarantee(::msem_init(p_sig_msem, 0) == p_sig_msem, "msem_init failed");
1742   }
1743 }
1744 
1745 static void local_sem_post() {
1746   static bool warn_only_once = false;
1747   if (os::Aix::on_aix()) {
1748     int rc = ::sem_post(&sig_sem);
1749     if (rc == -1 && !warn_only_once) {
1750       trcVerbose("sem_post failed (errno = %d, %s)", errno, os::errno_name(errno));
1751       warn_only_once = true;
1752     }
1753   } else {
1754     guarantee0(p_sig_msem != NULL);
1755     int rc = ::msem_unlock(p_sig_msem, 0);
1756     if (rc == -1 && !warn_only_once) {
1757       trcVerbose("msem_unlock failed (errno = %d, %s)", errno, os::errno_name(errno));
1758       warn_only_once = true;
1759     }
1760   }
1761 }
1762 
1763 static void local_sem_wait() {
1764   static bool warn_only_once = false;
1765   if (os::Aix::on_aix()) {
1766     int rc = ::sem_wait(&sig_sem);
1767     if (rc == -1 && !warn_only_once) {
1768       trcVerbose("sem_wait failed (errno = %d, %s)", errno, os::errno_name(errno));
1769       warn_only_once = true;
1770     }
1771   } else {
1772     guarantee0(p_sig_msem != NULL); // must init before use
1773     int rc = ::msem_lock(p_sig_msem, 0);
1774     if (rc == -1 && !warn_only_once) {
1775       trcVerbose("msem_lock failed (errno = %d, %s)", errno, os::errno_name(errno));
1776       warn_only_once = true;
1777     }
1778   }
1779 }
1780 
1781 static void jdk_misc_signal_init() {
1782   // Initialize signal structures
1783   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1784 
1785   // Initialize signal semaphore
1786   local_sem_init();
1787 }
1788 
1789 void os::signal_notify(int sig) {
1790   Atomic::inc(&pending_signals[sig]);
1791   local_sem_post();
1792 }
1793 
1794 static int check_pending_signals() {
1795   for (;;) {
1796     for (int i = 0; i < NSIG + 1; i++) {
1797       jint n = pending_signals[i];
1798       if (n > 0 && n == Atomic::cmpxchg(&pending_signals[i], n, n - 1)) {
1799         return i;
1800       }
1801     }
1802     JavaThread *thread = JavaThread::current();
1803     ThreadBlockInVM tbivm(thread);
1804 
1805     bool threadIsSuspended;
1806     do {
1807       thread->set_suspend_equivalent();
1808       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1809 
1810       local_sem_wait();
1811 
1812       // were we externally suspended while we were waiting?
1813       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1814       if (threadIsSuspended) {
1815         //
1816         // The semaphore has been incremented, but while we were waiting
1817         // another thread suspended us. We don't want to continue running
1818         // while suspended because that would surprise the thread that
1819         // suspended us.
1820         //
1821 
1822         local_sem_post();
1823 
1824         thread->java_suspend_self();
1825       }
1826     } while (threadIsSuspended);
1827   }
1828 }
1829 
1830 int os::signal_wait() {
1831   return check_pending_signals();
1832 }
1833 
1834 ////////////////////////////////////////////////////////////////////////////////
1835 // Virtual Memory
1836 
1837 // We need to keep small simple bookkeeping for os::reserve_memory and friends.
1838 
1839 #define VMEM_MAPPED  1
1840 #define VMEM_SHMATED 2
1841 
1842 struct vmembk_t {
1843   int type;         // 1 - mmap, 2 - shmat
1844   char* addr;
1845   size_t size;      // Real size, may be larger than usersize.
1846   size_t pagesize;  // page size of area
1847   vmembk_t* next;
1848 
1849   bool contains_addr(char* p) const {
1850     return p >= addr && p < (addr + size);
1851   }
1852 
1853   bool contains_range(char* p, size_t s) const {
1854     return contains_addr(p) && contains_addr(p + s - 1);
1855   }
1856 
1857   void print_on(outputStream* os) const {
1858     os->print("[" PTR_FORMAT " - " PTR_FORMAT "] (" UINTX_FORMAT
1859       " bytes, %d %s pages), %s",
1860       addr, addr + size - 1, size, size / pagesize, describe_pagesize(pagesize),
1861       (type == VMEM_SHMATED ? "shmat" : "mmap")
1862     );
1863   }
1864 
1865   // Check that range is a sub range of memory block (or equal to memory block);
1866   // also check that range is fully page aligned to the page size if the block.
1867   void assert_is_valid_subrange(char* p, size_t s) const {
1868     if (!contains_range(p, s)) {
1869       trcVerbose("[" PTR_FORMAT " - " PTR_FORMAT "] is not a sub "
1870               "range of [" PTR_FORMAT " - " PTR_FORMAT "].",
1871               p2i(p), p2i(p + s), p2i(addr), p2i(addr + size));
1872       guarantee0(false);
1873     }
1874     if (!is_aligned_to(p, pagesize) || !is_aligned_to(p + s, pagesize)) {
1875       trcVerbose("range [" PTR_FORMAT " - " PTR_FORMAT "] is not"
1876               " aligned to pagesize (%lu)", p2i(p), p2i(p + s), (unsigned long) pagesize);
1877       guarantee0(false);
1878     }
1879   }
1880 };
1881 
1882 static struct {
1883   vmembk_t* first;
1884   MiscUtils::CritSect cs;
1885 } vmem;
1886 
1887 static void vmembk_add(char* addr, size_t size, size_t pagesize, int type) {
1888   vmembk_t* p = (vmembk_t*) ::malloc(sizeof(vmembk_t));
1889   assert0(p);
1890   if (p) {
1891     MiscUtils::AutoCritSect lck(&vmem.cs);
1892     p->addr = addr; p->size = size;
1893     p->pagesize = pagesize;
1894     p->type = type;
1895     p->next = vmem.first;
1896     vmem.first = p;
1897   }
1898 }
1899 
1900 static vmembk_t* vmembk_find(char* addr) {
1901   MiscUtils::AutoCritSect lck(&vmem.cs);
1902   for (vmembk_t* p = vmem.first; p; p = p->next) {
1903     if (p->addr <= addr && (p->addr + p->size) > addr) {
1904       return p;
1905     }
1906   }
1907   return NULL;
1908 }
1909 
1910 static void vmembk_remove(vmembk_t* p0) {
1911   MiscUtils::AutoCritSect lck(&vmem.cs);
1912   assert0(p0);
1913   assert0(vmem.first); // List should not be empty.
1914   for (vmembk_t** pp = &(vmem.first); *pp; pp = &((*pp)->next)) {
1915     if (*pp == p0) {
1916       *pp = p0->next;
1917       ::free(p0);
1918       return;
1919     }
1920   }
1921   assert0(false); // Not found?
1922 }
1923 
1924 static void vmembk_print_on(outputStream* os) {
1925   MiscUtils::AutoCritSect lck(&vmem.cs);
1926   for (vmembk_t* vmi = vmem.first; vmi; vmi = vmi->next) {
1927     vmi->print_on(os);
1928     os->cr();
1929   }
1930 }
1931 
1932 // Reserve and attach a section of System V memory.
1933 // If <requested_addr> is not NULL, function will attempt to attach the memory at the given
1934 // address. Failing that, it will attach the memory anywhere.
1935 // If <requested_addr> is NULL, function will attach the memory anywhere.
1936 //
1937 // <alignment_hint> is being ignored by this function. It is very probable however that the
1938 // alignment requirements are met anyway, because shmat() attaches at 256M boundaries.
1939 // Should this be not enogh, we can put more work into it.
1940 static char* reserve_shmated_memory (
1941   size_t bytes,
1942   char* requested_addr,
1943   size_t alignment_hint) {
1944 
1945   trcVerbose("reserve_shmated_memory " UINTX_FORMAT " bytes, wishaddress "
1946     PTR_FORMAT ", alignment_hint " UINTX_FORMAT "...",
1947     bytes, p2i(requested_addr), alignment_hint);
1948 
1949   // Either give me wish address or wish alignment but not both.
1950   assert0(!(requested_addr != NULL && alignment_hint != 0));
1951 
1952   // We must prevent anyone from attaching too close to the
1953   // BRK because that may cause malloc OOM.
1954   if (requested_addr != NULL && is_close_to_brk((address)requested_addr)) {
1955     trcVerbose("Wish address " PTR_FORMAT " is too close to the BRK segment. "
1956       "Will attach anywhere.", p2i(requested_addr));
1957     // Act like the OS refused to attach there.
1958     requested_addr = NULL;
1959   }
1960 
1961   // For old AS/400's (V5R4 and older) we should not even be here - System V shared memory is not
1962   // really supported (max size 4GB), so reserve_mmapped_memory should have been used instead.
1963   if (os::Aix::on_pase_V5R4_or_older()) {
1964     ShouldNotReachHere();
1965   }
1966 
1967   // Align size of shm up to 64K to avoid errors if we later try to change the page size.
1968   const size_t size = align_up(bytes, 64*K);
1969 
1970   // Reserve the shared segment.
1971   int shmid = shmget(IPC_PRIVATE, size, IPC_CREAT | S_IRUSR | S_IWUSR);
1972   if (shmid == -1) {
1973     trcVerbose("shmget(.., " UINTX_FORMAT ", ..) failed (errno: %d).", size, errno);
1974     return NULL;
1975   }
1976 
1977   // Important note:
1978   // It is very important that we, upon leaving this function, do not leave a shm segment alive.
1979   // We must right after attaching it remove it from the system. System V shm segments are global and
1980   // survive the process.
1981   // So, from here on: Do not assert, do not return, until we have called shmctl(IPC_RMID) (A).
1982 
1983   struct shmid_ds shmbuf;
1984   memset(&shmbuf, 0, sizeof(shmbuf));
1985   shmbuf.shm_pagesize = 64*K;
1986   if (shmctl(shmid, SHM_PAGESIZE, &shmbuf) != 0) {
1987     trcVerbose("Failed to set page size (need " UINTX_FORMAT " 64K pages) - shmctl failed with %d.",
1988                size / (64*K), errno);
1989     // I want to know if this ever happens.
1990     assert(false, "failed to set page size for shmat");
1991   }
1992 
1993   // Now attach the shared segment.
1994   // Note that I attach with SHM_RND - which means that the requested address is rounded down, if
1995   // needed, to the next lowest segment boundary. Otherwise the attach would fail if the address
1996   // were not a segment boundary.
1997   char* const addr = (char*) shmat(shmid, requested_addr, SHM_RND);
1998   const int errno_shmat = errno;
1999 
2000   // (A) Right after shmat and before handing shmat errors delete the shm segment.
2001   if (::shmctl(shmid, IPC_RMID, NULL) == -1) {
2002     trcVerbose("shmctl(%u, IPC_RMID) failed (%d)\n", shmid, errno);
2003     assert(false, "failed to remove shared memory segment!");
2004   }
2005 
2006   // Handle shmat error. If we failed to attach, just return.
2007   if (addr == (char*)-1) {
2008     trcVerbose("Failed to attach segment at " PTR_FORMAT " (%d).", p2i(requested_addr), errno_shmat);
2009     return NULL;
2010   }
2011 
2012   // Just for info: query the real page size. In case setting the page size did not
2013   // work (see above), the system may have given us something other then 4K (LDR_CNTRL).
2014   const size_t real_pagesize = os::Aix::query_pagesize(addr);
2015   if (real_pagesize != shmbuf.shm_pagesize) {
2016     trcVerbose("pagesize is, surprisingly, " SIZE_FORMAT, real_pagesize);
2017   }
2018 
2019   if (addr) {
2020     trcVerbose("shm-allocated " PTR_FORMAT " .. " PTR_FORMAT " (" UINTX_FORMAT " bytes, " UINTX_FORMAT " %s pages)",
2021       p2i(addr), p2i(addr + size - 1), size, size/real_pagesize, describe_pagesize(real_pagesize));
2022   } else {
2023     if (requested_addr != NULL) {
2024       trcVerbose("failed to shm-allocate " UINTX_FORMAT " bytes at with address " PTR_FORMAT ".", size, p2i(requested_addr));
2025     } else {
2026       trcVerbose("failed to shm-allocate " UINTX_FORMAT " bytes at any address.", size);
2027     }
2028   }
2029 
2030   // book-keeping
2031   vmembk_add(addr, size, real_pagesize, VMEM_SHMATED);
2032   assert0(is_aligned_to(addr, os::vm_page_size()));
2033 
2034   return addr;
2035 }
2036 
2037 static bool release_shmated_memory(char* addr, size_t size) {
2038 
2039   trcVerbose("release_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2040     p2i(addr), p2i(addr + size - 1));
2041 
2042   bool rc = false;
2043 
2044   // TODO: is there a way to verify shm size without doing bookkeeping?
2045   if (::shmdt(addr) != 0) {
2046     trcVerbose("error (%d).", errno);
2047   } else {
2048     trcVerbose("ok.");
2049     rc = true;
2050   }
2051   return rc;
2052 }
2053 
2054 static bool uncommit_shmated_memory(char* addr, size_t size) {
2055   trcVerbose("uncommit_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2056     p2i(addr), p2i(addr + size - 1));
2057 
2058   const bool rc = my_disclaim64(addr, size);
2059 
2060   if (!rc) {
2061     trcVerbose("my_disclaim64(" PTR_FORMAT ", " UINTX_FORMAT ") failed.\n", p2i(addr), size);
2062     return false;
2063   }
2064   return true;
2065 }
2066 
2067 ////////////////////////////////  mmap-based routines /////////////////////////////////
2068 
2069 // Reserve memory via mmap.
2070 // If <requested_addr> is given, an attempt is made to attach at the given address.
2071 // Failing that, memory is allocated at any address.
2072 // If <alignment_hint> is given and <requested_addr> is NULL, an attempt is made to
2073 // allocate at an address aligned with the given alignment. Failing that, memory
2074 // is aligned anywhere.
2075 static char* reserve_mmaped_memory(size_t bytes, char* requested_addr, size_t alignment_hint) {
2076   trcVerbose("reserve_mmaped_memory " UINTX_FORMAT " bytes, wishaddress " PTR_FORMAT ", "
2077     "alignment_hint " UINTX_FORMAT "...",
2078     bytes, p2i(requested_addr), alignment_hint);
2079 
2080   // If a wish address is given, but not aligned to 4K page boundary, mmap will fail.
2081   if (requested_addr && !is_aligned_to(requested_addr, os::vm_page_size()) != 0) {
2082     trcVerbose("Wish address " PTR_FORMAT " not aligned to page boundary.", p2i(requested_addr));
2083     return NULL;
2084   }
2085 
2086   // We must prevent anyone from attaching too close to the
2087   // BRK because that may cause malloc OOM.
2088   if (requested_addr != NULL && is_close_to_brk((address)requested_addr)) {
2089     trcVerbose("Wish address " PTR_FORMAT " is too close to the BRK segment. "
2090       "Will attach anywhere.", p2i(requested_addr));
2091     // Act like the OS refused to attach there.
2092     requested_addr = NULL;
2093   }
2094 
2095   // Specify one or the other but not both.
2096   assert0(!(requested_addr != NULL && alignment_hint > 0));
2097 
2098   // In 64K mode, we claim the global page size (os::vm_page_size())
2099   // is 64K. This is one of the few points where that illusion may
2100   // break, because mmap() will always return memory aligned to 4K. So
2101   // we must ensure we only ever return memory aligned to 64k.
2102   if (alignment_hint) {
2103     alignment_hint = lcm(alignment_hint, os::vm_page_size());
2104   } else {
2105     alignment_hint = os::vm_page_size();
2106   }
2107 
2108   // Size shall always be a multiple of os::vm_page_size (esp. in 64K mode).
2109   const size_t size = align_up(bytes, os::vm_page_size());
2110 
2111   // alignment: Allocate memory large enough to include an aligned range of the right size and
2112   // cut off the leading and trailing waste pages.
2113   assert0(alignment_hint != 0 && is_aligned_to(alignment_hint, os::vm_page_size())); // see above
2114   const size_t extra_size = size + alignment_hint;
2115 
2116   // Note: MAP_SHARED (instead of MAP_PRIVATE) needed to be able to
2117   // later use msync(MS_INVALIDATE) (see os::uncommit_memory).
2118   int flags = MAP_ANONYMOUS | MAP_SHARED;
2119 
2120   // MAP_FIXED is needed to enforce requested_addr - manpage is vague about what
2121   // it means if wishaddress is given but MAP_FIXED is not set.
2122   //
2123   // Important! Behaviour differs depending on whether SPEC1170 mode is active or not.
2124   // SPEC1170 mode active: behaviour like POSIX, MAP_FIXED will clobber existing mappings.
2125   // SPEC1170 mode not active: behaviour, unlike POSIX, is that no existing mappings will
2126   // get clobbered.
2127   if (requested_addr != NULL) {
2128     if (!os::Aix::xpg_sus_mode()) {  // not SPEC1170 Behaviour
2129       flags |= MAP_FIXED;
2130     }
2131   }
2132 
2133   char* addr = (char*)::mmap(requested_addr, extra_size,
2134       PROT_READ|PROT_WRITE|PROT_EXEC, flags, -1, 0);
2135 
2136   if (addr == MAP_FAILED) {
2137     trcVerbose("mmap(" PTR_FORMAT ", " UINTX_FORMAT ", ..) failed (%d)", p2i(requested_addr), size, errno);
2138     return NULL;
2139   }
2140 
2141   // Handle alignment.
2142   char* const addr_aligned = align_up(addr, alignment_hint);
2143   const size_t waste_pre = addr_aligned - addr;
2144   char* const addr_aligned_end = addr_aligned + size;
2145   const size_t waste_post = extra_size - waste_pre - size;
2146   if (waste_pre > 0) {
2147     ::munmap(addr, waste_pre);
2148   }
2149   if (waste_post > 0) {
2150     ::munmap(addr_aligned_end, waste_post);
2151   }
2152   addr = addr_aligned;
2153 
2154   if (addr) {
2155     trcVerbose("mmap-allocated " PTR_FORMAT " .. " PTR_FORMAT " (" UINTX_FORMAT " bytes)",
2156       p2i(addr), p2i(addr + bytes), bytes);
2157   } else {
2158     if (requested_addr != NULL) {
2159       trcVerbose("failed to mmap-allocate " UINTX_FORMAT " bytes at wish address " PTR_FORMAT ".", bytes, p2i(requested_addr));
2160     } else {
2161       trcVerbose("failed to mmap-allocate " UINTX_FORMAT " bytes at any address.", bytes);
2162     }
2163   }
2164 
2165   // bookkeeping
2166   vmembk_add(addr, size, 4*K, VMEM_MAPPED);
2167 
2168   // Test alignment, see above.
2169   assert0(is_aligned_to(addr, os::vm_page_size()));
2170 
2171   return addr;
2172 }
2173 
2174 static bool release_mmaped_memory(char* addr, size_t size) {
2175   assert0(is_aligned_to(addr, os::vm_page_size()));
2176   assert0(is_aligned_to(size, os::vm_page_size()));
2177 
2178   trcVerbose("release_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2179     p2i(addr), p2i(addr + size - 1));
2180   bool rc = false;
2181 
2182   if (::munmap(addr, size) != 0) {
2183     trcVerbose("failed (%d)\n", errno);
2184     rc = false;
2185   } else {
2186     trcVerbose("ok.");
2187     rc = true;
2188   }
2189 
2190   return rc;
2191 }
2192 
2193 static bool uncommit_mmaped_memory(char* addr, size_t size) {
2194 
2195   assert0(is_aligned_to(addr, os::vm_page_size()));
2196   assert0(is_aligned_to(size, os::vm_page_size()));
2197 
2198   trcVerbose("uncommit_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2199     p2i(addr), p2i(addr + size - 1));
2200   bool rc = false;
2201 
2202   // Uncommit mmap memory with msync MS_INVALIDATE.
2203   if (::msync(addr, size, MS_INVALIDATE) != 0) {
2204     trcVerbose("failed (%d)\n", errno);
2205     rc = false;
2206   } else {
2207     trcVerbose("ok.");
2208     rc = true;
2209   }
2210 
2211   return rc;
2212 }
2213 
2214 int os::vm_page_size() {
2215   // Seems redundant as all get out.
2216   assert(os::Aix::page_size() != -1, "must call os::init");
2217   return os::Aix::page_size();
2218 }
2219 
2220 // Aix allocates memory by pages.
2221 int os::vm_allocation_granularity() {
2222   assert(os::Aix::page_size() != -1, "must call os::init");
2223   return os::Aix::page_size();
2224 }
2225 
2226 #ifdef PRODUCT
2227 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2228                                     int err) {
2229   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2230           ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
2231           os::errno_name(err), err);
2232 }
2233 #endif
2234 
2235 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2236                                   const char* mesg) {
2237   assert(mesg != NULL, "mesg must be specified");
2238   if (!pd_commit_memory(addr, size, exec)) {
2239     // Add extra info in product mode for vm_exit_out_of_memory():
2240     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2241     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2242   }
2243 }
2244 
2245 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2246 
2247   assert(is_aligned_to(addr, os::vm_page_size()),
2248     "addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2249     p2i(addr), os::vm_page_size());
2250   assert(is_aligned_to(size, os::vm_page_size()),
2251     "size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2252     size, os::vm_page_size());
2253 
2254   vmembk_t* const vmi = vmembk_find(addr);
2255   guarantee0(vmi);
2256   vmi->assert_is_valid_subrange(addr, size);
2257 
2258   trcVerbose("commit_memory [" PTR_FORMAT " - " PTR_FORMAT "].", p2i(addr), p2i(addr + size - 1));
2259 
2260   if (UseExplicitCommit) {
2261     // AIX commits memory on touch. So, touch all pages to be committed.
2262     for (char* p = addr; p < (addr + size); p += 4*K) {
2263       *p = '\0';
2264     }
2265   }
2266 
2267   return true;
2268 }
2269 
2270 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, bool exec) {
2271   return pd_commit_memory(addr, size, exec);
2272 }
2273 
2274 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2275                                   size_t alignment_hint, bool exec,
2276                                   const char* mesg) {
2277   // Alignment_hint is ignored on this OS.
2278   pd_commit_memory_or_exit(addr, size, exec, mesg);
2279 }
2280 
2281 bool os::pd_uncommit_memory(char* addr, size_t size) {
2282   assert(is_aligned_to(addr, os::vm_page_size()),
2283     "addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2284     p2i(addr), os::vm_page_size());
2285   assert(is_aligned_to(size, os::vm_page_size()),
2286     "size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2287     size, os::vm_page_size());
2288 
2289   // Dynamically do different things for mmap/shmat.
2290   const vmembk_t* const vmi = vmembk_find(addr);
2291   guarantee0(vmi);
2292   vmi->assert_is_valid_subrange(addr, size);
2293 
2294   if (vmi->type == VMEM_SHMATED) {
2295     return uncommit_shmated_memory(addr, size);
2296   } else {
2297     return uncommit_mmaped_memory(addr, size);
2298   }
2299 }
2300 
2301 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2302   // Do not call this; no need to commit stack pages on AIX.
2303   ShouldNotReachHere();
2304   return true;
2305 }
2306 
2307 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2308   // Do not call this; no need to commit stack pages on AIX.
2309   ShouldNotReachHere();
2310   return true;
2311 }
2312 
2313 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2314 }
2315 
2316 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2317 }
2318 
2319 void os::numa_make_global(char *addr, size_t bytes) {
2320 }
2321 
2322 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2323 }
2324 
2325 bool os::numa_topology_changed() {
2326   return false;
2327 }
2328 
2329 size_t os::numa_get_groups_num() {
2330   return 1;
2331 }
2332 
2333 int os::numa_get_group_id() {
2334   return 0;
2335 }
2336 
2337 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2338   if (size > 0) {
2339     ids[0] = 0;
2340     return 1;
2341   }
2342   return 0;
2343 }
2344 
2345 int os::numa_get_group_id_for_address(const void* address) {
2346   return 0;
2347 }
2348 
2349 bool os::get_page_info(char *start, page_info* info) {
2350   return false;
2351 }
2352 
2353 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2354   return end;
2355 }
2356 
2357 // Reserves and attaches a shared memory segment.
2358 // Will assert if a wish address is given and could not be obtained.
2359 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, size_t alignment_hint) {
2360 
2361   // All other Unices do a mmap(MAP_FIXED) if the addr is given,
2362   // thereby clobbering old mappings at that place. That is probably
2363   // not intended, never used and almost certainly an error were it
2364   // ever be used this way (to try attaching at a specified address
2365   // without clobbering old mappings an alternate API exists,
2366   // os::attempt_reserve_memory_at()).
2367   // Instead of mimicking the dangerous coding of the other platforms, here I
2368   // just ignore the request address (release) or assert(debug).
2369   assert0(requested_addr == NULL);
2370 
2371   // Always round to os::vm_page_size(), which may be larger than 4K.
2372   bytes = align_up(bytes, os::vm_page_size());
2373   const size_t alignment_hint0 =
2374     alignment_hint ? align_up(alignment_hint, os::vm_page_size()) : 0;
2375 
2376   // In 4K mode always use mmap.
2377   // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2378   if (os::vm_page_size() == 4*K) {
2379     return reserve_mmaped_memory(bytes, requested_addr, alignment_hint);
2380   } else {
2381     if (bytes >= Use64KPagesThreshold) {
2382       return reserve_shmated_memory(bytes, requested_addr, alignment_hint);
2383     } else {
2384       return reserve_mmaped_memory(bytes, requested_addr, alignment_hint);
2385     }
2386   }
2387 }
2388 
2389 bool os::pd_release_memory(char* addr, size_t size) {
2390 
2391   // Dynamically do different things for mmap/shmat.
2392   vmembk_t* const vmi = vmembk_find(addr);
2393   guarantee0(vmi);
2394 
2395   // Always round to os::vm_page_size(), which may be larger than 4K.
2396   size = align_up(size, os::vm_page_size());
2397   addr = align_up(addr, os::vm_page_size());
2398 
2399   bool rc = false;
2400   bool remove_bookkeeping = false;
2401   if (vmi->type == VMEM_SHMATED) {
2402     // For shmatted memory, we do:
2403     // - If user wants to release the whole range, release the memory (shmdt).
2404     // - If user only wants to release a partial range, uncommit (disclaim) that
2405     //   range. That way, at least, we do not use memory anymore (bust still page
2406     //   table space).
2407     vmi->assert_is_valid_subrange(addr, size);
2408     if (addr == vmi->addr && size == vmi->size) {
2409       rc = release_shmated_memory(addr, size);
2410       remove_bookkeeping = true;
2411     } else {
2412       rc = uncommit_shmated_memory(addr, size);
2413     }
2414   } else {
2415     // User may unmap partial regions but region has to be fully contained.
2416 #ifdef ASSERT
2417     vmi->assert_is_valid_subrange(addr, size);
2418 #endif
2419     rc = release_mmaped_memory(addr, size);
2420     remove_bookkeeping = true;
2421   }
2422 
2423   // update bookkeeping
2424   if (rc && remove_bookkeeping) {
2425     vmembk_remove(vmi);
2426   }
2427 
2428   return rc;
2429 }
2430 
2431 static bool checked_mprotect(char* addr, size_t size, int prot) {
2432 
2433   // Little problem here: if SPEC1170 behaviour is off, mprotect() on AIX will
2434   // not tell me if protection failed when trying to protect an un-protectable range.
2435   //
2436   // This means if the memory was allocated using shmget/shmat, protection wont work
2437   // but mprotect will still return 0:
2438   //
2439   // See http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.basetechref/doc/basetrf1/mprotect.htm
2440 
2441   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
2442   bool rc = ::mprotect(addr, size, prot) == 0 ? true : false;
2443 
2444   if (!rc) {
2445     const char* const s_errno = os::errno_name(errno);
2446     warning("mprotect(" PTR_FORMAT "-" PTR_FORMAT ", 0x%X) failed (%s).", addr, addr + size, prot, s_errno);
2447     return false;
2448   }
2449 
2450   // mprotect success check
2451   //
2452   // Mprotect said it changed the protection but can I believe it?
2453   //
2454   // To be sure I need to check the protection afterwards. Try to
2455   // read from protected memory and check whether that causes a segfault.
2456   //
2457   if (!os::Aix::xpg_sus_mode()) {
2458 
2459     if (CanUseSafeFetch32()) {
2460 
2461       const bool read_protected =
2462         (SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
2463          SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
2464 
2465       if (prot & PROT_READ) {
2466         rc = !read_protected;
2467       } else {
2468         rc = read_protected;
2469       }
2470 
2471       if (!rc) {
2472         if (os::Aix::on_pase()) {
2473           // There is an issue on older PASE systems where mprotect() will return success but the
2474           // memory will not be protected.
2475           // This has nothing to do with the problem of using mproect() on SPEC1170 incompatible
2476           // machines; we only see it rarely, when using mprotect() to protect the guard page of
2477           // a stack. It is an OS error.
2478           //
2479           // A valid strategy is just to try again. This usually works. :-/
2480 
2481           ::usleep(1000);
2482           Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
2483           if (::mprotect(addr, size, prot) == 0) {
2484             const bool read_protected_2 =
2485               (SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
2486               SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
2487             rc = true;
2488           }
2489         }
2490       }
2491     }
2492   }
2493 
2494   assert(rc == true, "mprotect failed.");
2495 
2496   return rc;
2497 }
2498 
2499 // Set protections specified
2500 bool os::protect_memory(char* addr, size_t size, ProtType prot, bool is_committed) {
2501   unsigned int p = 0;
2502   switch (prot) {
2503   case MEM_PROT_NONE: p = PROT_NONE; break;
2504   case MEM_PROT_READ: p = PROT_READ; break;
2505   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2506   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2507   default:
2508     ShouldNotReachHere();
2509   }
2510   // is_committed is unused.
2511   return checked_mprotect(addr, size, p);
2512 }
2513 
2514 bool os::guard_memory(char* addr, size_t size) {
2515   return checked_mprotect(addr, size, PROT_NONE);
2516 }
2517 
2518 bool os::unguard_memory(char* addr, size_t size) {
2519   return checked_mprotect(addr, size, PROT_READ|PROT_WRITE|PROT_EXEC);
2520 }
2521 
2522 // Large page support
2523 
2524 static size_t _large_page_size = 0;
2525 
2526 // Enable large page support if OS allows that.
2527 void os::large_page_init() {
2528   return; // Nothing to do. See query_multipage_support and friends.
2529 }
2530 
2531 char* os::pd_reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2532   fatal("os::reserve_memory_special should not be called on AIX.");
2533   return NULL;
2534 }
2535 
2536 bool os::pd_release_memory_special(char* base, size_t bytes) {
2537   fatal("os::release_memory_special should not be called on AIX.");
2538   return false;
2539 }
2540 
2541 size_t os::large_page_size() {
2542   return _large_page_size;
2543 }
2544 
2545 bool os::can_commit_large_page_memory() {
2546   // Does not matter, we do not support huge pages.
2547   return false;
2548 }
2549 
2550 bool os::can_execute_large_page_memory() {
2551   // Does not matter, we do not support huge pages.
2552   return false;
2553 }
2554 
2555 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2556   assert(file_desc >= 0, "file_desc is not valid");
2557   char* result = NULL;
2558 
2559   // Always round to os::vm_page_size(), which may be larger than 4K.
2560   bytes = align_up(bytes, os::vm_page_size());
2561   result = reserve_mmaped_memory(bytes, requested_addr, 0);
2562 
2563   if (result != NULL) {
2564     if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2565       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2566     }
2567   }
2568   return result;
2569 }
2570 
2571 // Reserve memory at an arbitrary address, only if that area is
2572 // available (and not reserved for something else).
2573 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2574   char* addr = NULL;
2575 
2576   // Always round to os::vm_page_size(), which may be larger than 4K.
2577   bytes = align_up(bytes, os::vm_page_size());
2578 
2579   // In 4K mode always use mmap.
2580   // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2581   if (os::vm_page_size() == 4*K) {
2582     return reserve_mmaped_memory(bytes, requested_addr, 0);
2583   } else {
2584     if (bytes >= Use64KPagesThreshold) {
2585       return reserve_shmated_memory(bytes, requested_addr, 0);
2586     } else {
2587       return reserve_mmaped_memory(bytes, requested_addr, 0);
2588     }
2589   }
2590 
2591   return addr;
2592 }
2593 
2594 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2595 void os::infinite_sleep() {
2596   while (true) {    // sleep forever ...
2597     ::sleep(100);   // ... 100 seconds at a time
2598   }
2599 }
2600 
2601 // Used to convert frequent JVM_Yield() to nops
2602 bool os::dont_yield() {
2603   return DontYieldALot;
2604 }
2605 
2606 void os::naked_yield() {
2607   sched_yield();
2608 }
2609 
2610 ////////////////////////////////////////////////////////////////////////////////
2611 // thread priority support
2612 
2613 // From AIX manpage to pthread_setschedparam
2614 // (see: http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?
2615 //    topic=/com.ibm.aix.basetechref/doc/basetrf1/pthread_setschedparam.htm):
2616 //
2617 // "If schedpolicy is SCHED_OTHER, then sched_priority must be in the
2618 // range from 40 to 80, where 40 is the least favored priority and 80
2619 // is the most favored."
2620 //
2621 // (Actually, I doubt this even has an impact on AIX, as we do kernel
2622 // scheduling there; however, this still leaves iSeries.)
2623 //
2624 // We use the same values for AIX and PASE.
2625 int os::java_to_os_priority[CriticalPriority + 1] = {
2626   54,             // 0 Entry should never be used
2627 
2628   55,             // 1 MinPriority
2629   55,             // 2
2630   56,             // 3
2631 
2632   56,             // 4
2633   57,             // 5 NormPriority
2634   57,             // 6
2635 
2636   58,             // 7
2637   58,             // 8
2638   59,             // 9 NearMaxPriority
2639 
2640   60,             // 10 MaxPriority
2641 
2642   60              // 11 CriticalPriority
2643 };
2644 
2645 static int prio_init() {
2646   if (ThreadPriorityPolicy == 1) {
2647     if (geteuid() != 0) {
2648       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy) && !FLAG_IS_JIMAGE_RESOURCE(ThreadPriorityPolicy)) {
2649         warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
2650                 "e.g., being the root user. If the necessary permission is not " \
2651                 "possessed, changes to priority will be silently ignored.");
2652       }
2653     }
2654   }
2655   if (UseCriticalJavaThreadPriority) {
2656     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2657   }
2658   return 0;
2659 }
2660 
2661 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2662   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2663   pthread_t thr = thread->osthread()->pthread_id();
2664   int policy = SCHED_OTHER;
2665   struct sched_param param;
2666   param.sched_priority = newpri;
2667   int ret = pthread_setschedparam(thr, policy, &param);
2668 
2669   if (ret != 0) {
2670     trcVerbose("Could not change priority for thread %d to %d (error %d, %s)",
2671         (int)thr, newpri, ret, os::errno_name(ret));
2672   }
2673   return (ret == 0) ? OS_OK : OS_ERR;
2674 }
2675 
2676 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2677   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2678     *priority_ptr = java_to_os_priority[NormPriority];
2679     return OS_OK;
2680   }
2681   pthread_t thr = thread->osthread()->pthread_id();
2682   int policy = SCHED_OTHER;
2683   struct sched_param param;
2684   int ret = pthread_getschedparam(thr, &policy, &param);
2685   *priority_ptr = param.sched_priority;
2686 
2687   return (ret == 0) ? OS_OK : OS_ERR;
2688 }
2689 
2690 ////////////////////////////////////////////////////////////////////////////////
2691 // suspend/resume support
2692 
2693 //  The low-level signal-based suspend/resume support is a remnant from the
2694 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2695 //  within hotspot. Currently used by JFR's OSThreadSampler
2696 //
2697 //  The remaining code is greatly simplified from the more general suspension
2698 //  code that used to be used.
2699 //
2700 //  The protocol is quite simple:
2701 //  - suspend:
2702 //      - sends a signal to the target thread
2703 //      - polls the suspend state of the osthread using a yield loop
2704 //      - target thread signal handler (SR_handler) sets suspend state
2705 //        and blocks in sigsuspend until continued
2706 //  - resume:
2707 //      - sets target osthread state to continue
2708 //      - sends signal to end the sigsuspend loop in the SR_handler
2709 //
2710 //  Note that the SR_lock plays no role in this suspend/resume protocol,
2711 //  but is checked for NULL in SR_handler as a thread termination indicator.
2712 //  The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
2713 //
2714 //  Note that resume_clear_context() and suspend_save_context() are needed
2715 //  by SR_handler(), so that fetch_frame_from_ucontext() works,
2716 //  which in part is used by:
2717 //    - Forte Analyzer: AsyncGetCallTrace()
2718 //    - StackBanging: get_frame_at_stack_banging_point()
2719 
2720 static void resume_clear_context(OSThread *osthread) {
2721   osthread->set_ucontext(NULL);
2722   osthread->set_siginfo(NULL);
2723 }
2724 
2725 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2726   osthread->set_ucontext(context);
2727   osthread->set_siginfo(siginfo);
2728 }
2729 
2730 //
2731 // Handler function invoked when a thread's execution is suspended or
2732 // resumed. We have to be careful that only async-safe functions are
2733 // called here (Note: most pthread functions are not async safe and
2734 // should be avoided.)
2735 //
2736 // Note: sigwait() is a more natural fit than sigsuspend() from an
2737 // interface point of view, but sigwait() prevents the signal hander
2738 // from being run. libpthread would get very confused by not having
2739 // its signal handlers run and prevents sigwait()'s use with the
2740 // mutex granting granting signal.
2741 //
2742 // Currently only ever called on the VMThread and JavaThreads (PC sampling).
2743 //
2744 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2745   // Save and restore errno to avoid confusing native code with EINTR
2746   // after sigsuspend.
2747   int old_errno = errno;
2748 
2749   Thread* thread = Thread::current_or_null_safe();
2750   assert(thread != NULL, "Missing current thread in SR_handler");
2751 
2752   // On some systems we have seen signal delivery get "stuck" until the signal
2753   // mask is changed as part of thread termination. Check that the current thread
2754   // has not already terminated (via SR_lock()) - else the following assertion
2755   // will fail because the thread is no longer a JavaThread as the ~JavaThread
2756   // destructor has completed.
2757 
2758   if (thread->SR_lock() == NULL) {
2759     return;
2760   }
2761 
2762   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2763 
2764   OSThread* osthread = thread->osthread();
2765 
2766   os::SuspendResume::State current = osthread->sr.state();
2767   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2768     suspend_save_context(osthread, siginfo, context);
2769 
2770     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2771     os::SuspendResume::State state = osthread->sr.suspended();
2772     if (state == os::SuspendResume::SR_SUSPENDED) {
2773       sigset_t suspend_set;  // signals for sigsuspend()
2774       sigemptyset(&suspend_set);
2775       // get current set of blocked signals and unblock resume signal
2776       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2777       sigdelset(&suspend_set, SR_signum);
2778 
2779       // wait here until we are resumed
2780       while (1) {
2781         sigsuspend(&suspend_set);
2782 
2783         os::SuspendResume::State result = osthread->sr.running();
2784         if (result == os::SuspendResume::SR_RUNNING) {
2785           break;
2786         }
2787       }
2788 
2789     } else if (state == os::SuspendResume::SR_RUNNING) {
2790       // request was cancelled, continue
2791     } else {
2792       ShouldNotReachHere();
2793     }
2794 
2795     resume_clear_context(osthread);
2796   } else if (current == os::SuspendResume::SR_RUNNING) {
2797     // request was cancelled, continue
2798   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2799     // ignore
2800   } else {
2801     ShouldNotReachHere();
2802   }
2803 
2804   errno = old_errno;
2805 }
2806 
2807 static int SR_initialize() {
2808   struct sigaction act;
2809   char *s;
2810   // Get signal number to use for suspend/resume
2811   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2812     int sig = ::strtol(s, 0, 10);
2813     if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
2814         sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
2815       SR_signum = sig;
2816     } else {
2817       warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2818               sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2819     }
2820   }
2821 
2822   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2823         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2824 
2825   sigemptyset(&SR_sigset);
2826   sigaddset(&SR_sigset, SR_signum);
2827 
2828   // Set up signal handler for suspend/resume.
2829   act.sa_flags = SA_RESTART|SA_SIGINFO;
2830   act.sa_handler = (void (*)(int)) SR_handler;
2831 
2832   // SR_signum is blocked by default.
2833   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2834 
2835   if (sigaction(SR_signum, &act, 0) == -1) {
2836     return -1;
2837   }
2838 
2839   // Save signal flag
2840   os::Aix::set_our_sigflags(SR_signum, act.sa_flags);
2841   return 0;
2842 }
2843 
2844 static int SR_finalize() {
2845   return 0;
2846 }
2847 
2848 static int sr_notify(OSThread* osthread) {
2849   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2850   assert_status(status == 0, status, "pthread_kill");
2851   return status;
2852 }
2853 
2854 // "Randomly" selected value for how long we want to spin
2855 // before bailing out on suspending a thread, also how often
2856 // we send a signal to a thread we want to resume
2857 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2858 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2859 
2860 // returns true on success and false on error - really an error is fatal
2861 // but this seems the normal response to library errors
2862 static bool do_suspend(OSThread* osthread) {
2863   assert(osthread->sr.is_running(), "thread should be running");
2864   // mark as suspended and send signal
2865 
2866   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2867     // failed to switch, state wasn't running?
2868     ShouldNotReachHere();
2869     return false;
2870   }
2871 
2872   if (sr_notify(osthread) != 0) {
2873     // try to cancel, switch to running
2874 
2875     os::SuspendResume::State result = osthread->sr.cancel_suspend();
2876     if (result == os::SuspendResume::SR_RUNNING) {
2877       // cancelled
2878       return false;
2879     } else if (result == os::SuspendResume::SR_SUSPENDED) {
2880       // somehow managed to suspend
2881       return true;
2882     } else {
2883       ShouldNotReachHere();
2884       return false;
2885     }
2886   }
2887 
2888   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2889 
2890   for (int n = 0; !osthread->sr.is_suspended(); n++) {
2891     for (int i = 0; i < RANDOMLY_LARGE_INTEGER2 && !osthread->sr.is_suspended(); i++) {
2892       os::naked_yield();
2893     }
2894 
2895     // timeout, try to cancel the request
2896     if (n >= RANDOMLY_LARGE_INTEGER) {
2897       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2898       if (cancelled == os::SuspendResume::SR_RUNNING) {
2899         return false;
2900       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2901         return true;
2902       } else {
2903         ShouldNotReachHere();
2904         return false;
2905       }
2906     }
2907   }
2908 
2909   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2910   return true;
2911 }
2912 
2913 static void do_resume(OSThread* osthread) {
2914   //assert(osthread->sr.is_suspended(), "thread should be suspended");
2915 
2916   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2917     // failed to switch to WAKEUP_REQUEST
2918     ShouldNotReachHere();
2919     return;
2920   }
2921 
2922   while (!osthread->sr.is_running()) {
2923     if (sr_notify(osthread) == 0) {
2924       for (int n = 0; n < RANDOMLY_LARGE_INTEGER && !osthread->sr.is_running(); n++) {
2925         for (int i = 0; i < 100 && !osthread->sr.is_running(); i++) {
2926           os::naked_yield();
2927         }
2928       }
2929     } else {
2930       ShouldNotReachHere();
2931     }
2932   }
2933 
2934   guarantee(osthread->sr.is_running(), "Must be running!");
2935 }
2936 
2937 ///////////////////////////////////////////////////////////////////////////////////
2938 // signal handling (except suspend/resume)
2939 
2940 // This routine may be used by user applications as a "hook" to catch signals.
2941 // The user-defined signal handler must pass unrecognized signals to this
2942 // routine, and if it returns true (non-zero), then the signal handler must
2943 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2944 // routine will never retun false (zero), but instead will execute a VM panic
2945 // routine kill the process.
2946 //
2947 // If this routine returns false, it is OK to call it again. This allows
2948 // the user-defined signal handler to perform checks either before or after
2949 // the VM performs its own checks. Naturally, the user code would be making
2950 // a serious error if it tried to handle an exception (such as a null check
2951 // or breakpoint) that the VM was generating for its own correct operation.
2952 //
2953 // This routine may recognize any of the following kinds of signals:
2954 //   SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2955 // It should be consulted by handlers for any of those signals.
2956 //
2957 // The caller of this routine must pass in the three arguments supplied
2958 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2959 // field of the structure passed to sigaction(). This routine assumes that
2960 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2961 //
2962 // Note that the VM will print warnings if it detects conflicting signal
2963 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2964 //
2965 extern "C" JNIEXPORT int
2966 JVM_handle_aix_signal(int signo, siginfo_t* siginfo, void* ucontext, int abort_if_unrecognized);
2967 
2968 // Set thread signal mask (for some reason on AIX sigthreadmask() seems
2969 // to be the thing to call; documentation is not terribly clear about whether
2970 // pthread_sigmask also works, and if it does, whether it does the same.
2971 bool set_thread_signal_mask(int how, const sigset_t* set, sigset_t* oset) {
2972   const int rc = ::pthread_sigmask(how, set, oset);
2973   // return value semantics differ slightly for error case:
2974   // pthread_sigmask returns error number, sigthreadmask -1 and sets global errno
2975   // (so, pthread_sigmask is more theadsafe for error handling)
2976   // But success is always 0.
2977   return rc == 0 ? true : false;
2978 }
2979 
2980 // Function to unblock all signals which are, according
2981 // to POSIX, typical program error signals. If they happen while being blocked,
2982 // they typically will bring down the process immediately.
2983 bool unblock_program_error_signals() {
2984   sigset_t set;
2985   ::sigemptyset(&set);
2986   ::sigaddset(&set, SIGILL);
2987   ::sigaddset(&set, SIGBUS);
2988   ::sigaddset(&set, SIGFPE);
2989   ::sigaddset(&set, SIGSEGV);
2990   return set_thread_signal_mask(SIG_UNBLOCK, &set, NULL);
2991 }
2992 
2993 // Renamed from 'signalHandler' to avoid collision with other shared libs.
2994 static void javaSignalHandler(int sig, siginfo_t* info, void* uc) {
2995   assert(info != NULL && uc != NULL, "it must be old kernel");
2996 
2997   // Never leave program error signals blocked;
2998   // on all our platforms they would bring down the process immediately when
2999   // getting raised while being blocked.
3000   unblock_program_error_signals();
3001 
3002   int orig_errno = errno;  // Preserve errno value over signal handler.
3003   JVM_handle_aix_signal(sig, info, uc, true);
3004   errno = orig_errno;
3005 }
3006 
3007 // This boolean allows users to forward their own non-matching signals
3008 // to JVM_handle_aix_signal, harmlessly.
3009 bool os::Aix::signal_handlers_are_installed = false;
3010 
3011 // For signal-chaining
3012 bool os::Aix::libjsig_is_loaded = false;
3013 typedef struct sigaction *(*get_signal_t)(int);
3014 get_signal_t os::Aix::get_signal_action = NULL;
3015 
3016 struct sigaction* os::Aix::get_chained_signal_action(int sig) {
3017   struct sigaction *actp = NULL;
3018 
3019   if (libjsig_is_loaded) {
3020     // Retrieve the old signal handler from libjsig
3021     actp = (*get_signal_action)(sig);
3022   }
3023   if (actp == NULL) {
3024     // Retrieve the preinstalled signal handler from jvm
3025     actp = os::Posix::get_preinstalled_handler(sig);
3026   }
3027 
3028   return actp;
3029 }
3030 
3031 static bool call_chained_handler(struct sigaction *actp, int sig,
3032                                  siginfo_t *siginfo, void *context) {
3033   // Call the old signal handler
3034   if (actp->sa_handler == SIG_DFL) {
3035     // It's more reasonable to let jvm treat it as an unexpected exception
3036     // instead of taking the default action.
3037     return false;
3038   } else if (actp->sa_handler != SIG_IGN) {
3039     if ((actp->sa_flags & SA_NODEFER) == 0) {
3040       // automaticlly block the signal
3041       sigaddset(&(actp->sa_mask), sig);
3042     }
3043 
3044     sa_handler_t hand = NULL;
3045     sa_sigaction_t sa = NULL;
3046     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3047     // retrieve the chained handler
3048     if (siginfo_flag_set) {
3049       sa = actp->sa_sigaction;
3050     } else {
3051       hand = actp->sa_handler;
3052     }
3053 
3054     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3055       actp->sa_handler = SIG_DFL;
3056     }
3057 
3058     // try to honor the signal mask
3059     sigset_t oset;
3060     sigemptyset(&oset);
3061     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3062 
3063     // call into the chained handler
3064     if (siginfo_flag_set) {
3065       (*sa)(sig, siginfo, context);
3066     } else {
3067       (*hand)(sig);
3068     }
3069 
3070     // restore the signal mask
3071     pthread_sigmask(SIG_SETMASK, &oset, NULL);
3072   }
3073   // Tell jvm's signal handler the signal is taken care of.
3074   return true;
3075 }
3076 
3077 bool os::Aix::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3078   bool chained = false;
3079   // signal-chaining
3080   if (UseSignalChaining) {
3081     struct sigaction *actp = get_chained_signal_action(sig);
3082     if (actp != NULL) {
3083       chained = call_chained_handler(actp, sig, siginfo, context);
3084     }
3085   }
3086   return chained;
3087 }
3088 
3089 // for diagnostic
3090 int sigflags[NSIG];
3091 
3092 int os::Aix::get_our_sigflags(int sig) {
3093   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3094   return sigflags[sig];
3095 }
3096 
3097 void os::Aix::set_our_sigflags(int sig, int flags) {
3098   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3099   if (sig > 0 && sig < NSIG) {
3100     sigflags[sig] = flags;
3101   }
3102 }
3103 
3104 void os::Aix::set_signal_handler(int sig, bool set_installed) {
3105   // Check for overwrite.
3106   struct sigaction oldAct;
3107   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3108 
3109   void* oldhand = oldAct.sa_sigaction
3110     ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3111     : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3112   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3113       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3114       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)javaSignalHandler)) {
3115     if (AllowUserSignalHandlers || !set_installed) {
3116       // Do not overwrite; user takes responsibility to forward to us.
3117       return;
3118     } else if (UseSignalChaining) {
3119       // save the old handler in jvm
3120       os::Posix::save_preinstalled_handler(sig, oldAct);
3121       // libjsig also interposes the sigaction() call below and saves the
3122       // old sigaction on it own.
3123     } else {
3124       fatal("Encountered unexpected pre-existing sigaction handler "
3125             "%#lx for signal %d.", (long)oldhand, sig);
3126     }
3127   }
3128 
3129   struct sigaction sigAct;
3130   sigfillset(&(sigAct.sa_mask));
3131   if (!set_installed) {
3132     sigAct.sa_handler = SIG_DFL;
3133     sigAct.sa_flags = SA_RESTART;
3134   } else {
3135     sigAct.sa_sigaction = javaSignalHandler;
3136     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3137   }
3138   // Save flags, which are set by ours
3139   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3140   sigflags[sig] = sigAct.sa_flags;
3141 
3142   int ret = sigaction(sig, &sigAct, &oldAct);
3143   assert(ret == 0, "check");
3144 
3145   void* oldhand2 = oldAct.sa_sigaction
3146                  ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3147                  : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3148   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3149 }
3150 
3151 // install signal handlers for signals that HotSpot needs to
3152 // handle in order to support Java-level exception handling.
3153 void os::Aix::install_signal_handlers() {
3154   if (!signal_handlers_are_installed) {
3155     signal_handlers_are_installed = true;
3156 
3157     // signal-chaining
3158     typedef void (*signal_setting_t)();
3159     signal_setting_t begin_signal_setting = NULL;
3160     signal_setting_t end_signal_setting = NULL;
3161     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3162                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3163     if (begin_signal_setting != NULL) {
3164       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3165                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3166       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3167                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3168       libjsig_is_loaded = true;
3169       assert(UseSignalChaining, "should enable signal-chaining");
3170     }
3171     if (libjsig_is_loaded) {
3172       // Tell libjsig jvm is setting signal handlers.
3173       (*begin_signal_setting)();
3174     }
3175 
3176     set_signal_handler(SIGSEGV, true);
3177     set_signal_handler(SIGPIPE, true);
3178     set_signal_handler(SIGBUS, true);
3179     set_signal_handler(SIGILL, true);
3180     set_signal_handler(SIGFPE, true);
3181     set_signal_handler(SIGTRAP, true);
3182     set_signal_handler(SIGXFSZ, true);
3183 
3184     if (libjsig_is_loaded) {
3185       // Tell libjsig jvm finishes setting signal handlers.
3186       (*end_signal_setting)();
3187     }
3188 
3189     // We don't activate signal checker if libjsig is in place, we trust ourselves
3190     // and if UserSignalHandler is installed all bets are off.
3191     // Log that signal checking is off only if -verbose:jni is specified.
3192     if (CheckJNICalls) {
3193       if (libjsig_is_loaded) {
3194         tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3195         check_signals = false;
3196       }
3197       if (AllowUserSignalHandlers) {
3198         tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3199         check_signals = false;
3200       }
3201       // Need to initialize check_signal_done.
3202       ::sigemptyset(&check_signal_done);
3203     }
3204   }
3205 }
3206 
3207 static const char* get_signal_handler_name(address handler,
3208                                            char* buf, int buflen) {
3209   int offset;
3210   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3211   if (found) {
3212     // skip directory names
3213     const char *p1, *p2;
3214     p1 = buf;
3215     size_t len = strlen(os::file_separator());
3216     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3217     // The way os::dll_address_to_library_name is implemented on Aix
3218     // right now, it always returns -1 for the offset which is not
3219     // terribly informative.
3220     // Will fix that. For now, omit the offset.
3221     jio_snprintf(buf, buflen, "%s", p1);
3222   } else {
3223     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3224   }
3225   return buf;
3226 }
3227 
3228 static void print_signal_handler(outputStream* st, int sig,
3229                                  char* buf, size_t buflen) {
3230   struct sigaction sa;
3231   sigaction(sig, NULL, &sa);
3232 
3233   st->print("%s: ", os::exception_name(sig, buf, buflen));
3234 
3235   address handler = (sa.sa_flags & SA_SIGINFO)
3236     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3237     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3238 
3239   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3240     st->print("SIG_DFL");
3241   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3242     st->print("SIG_IGN");
3243   } else {
3244     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3245   }
3246 
3247   // Print readable mask.
3248   st->print(", sa_mask[0]=");
3249   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3250 
3251   address rh = VMError::get_resetted_sighandler(sig);
3252   // May be, handler was resetted by VMError?
3253   if (rh != NULL) {
3254     handler = rh;
3255     sa.sa_flags = VMError::get_resetted_sigflags(sig);
3256   }
3257 
3258   // Print textual representation of sa_flags.
3259   st->print(", sa_flags=");
3260   os::Posix::print_sa_flags(st, sa.sa_flags);
3261 
3262   // Check: is it our handler?
3263   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)javaSignalHandler) ||
3264       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3265     // It is our signal handler.
3266     // Check for flags, reset system-used one!
3267     if ((int)sa.sa_flags != os::Aix::get_our_sigflags(sig)) {
3268       st->print(", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3269                 os::Aix::get_our_sigflags(sig));
3270     }
3271   }
3272   st->cr();
3273 }
3274 
3275 #define DO_SIGNAL_CHECK(sig) \
3276   if (!sigismember(&check_signal_done, sig)) \
3277     os::Aix::check_signal_handler(sig)
3278 
3279 // This method is a periodic task to check for misbehaving JNI applications
3280 // under CheckJNI, we can add any periodic checks here
3281 
3282 void os::run_periodic_checks() {
3283 
3284   if (check_signals == false) return;
3285 
3286   // SEGV and BUS if overridden could potentially prevent
3287   // generation of hs*.log in the event of a crash, debugging
3288   // such a case can be very challenging, so we absolutely
3289   // check the following for a good measure:
3290   DO_SIGNAL_CHECK(SIGSEGV);
3291   DO_SIGNAL_CHECK(SIGILL);
3292   DO_SIGNAL_CHECK(SIGFPE);
3293   DO_SIGNAL_CHECK(SIGBUS);
3294   DO_SIGNAL_CHECK(SIGPIPE);
3295   DO_SIGNAL_CHECK(SIGXFSZ);
3296   if (UseSIGTRAP) {
3297     DO_SIGNAL_CHECK(SIGTRAP);
3298   }
3299 
3300   // ReduceSignalUsage allows the user to override these handlers
3301   // see comments at the very top and jvm_md.h
3302   if (!ReduceSignalUsage) {
3303     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3304     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3305     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3306     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3307   }
3308 
3309   DO_SIGNAL_CHECK(SR_signum);
3310 }
3311 
3312 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3313 
3314 static os_sigaction_t os_sigaction = NULL;
3315 
3316 void os::Aix::check_signal_handler(int sig) {
3317   char buf[O_BUFLEN];
3318   address jvmHandler = NULL;
3319 
3320   struct sigaction act;
3321   if (os_sigaction == NULL) {
3322     // only trust the default sigaction, in case it has been interposed
3323     os_sigaction = CAST_TO_FN_PTR(os_sigaction_t, dlsym(RTLD_DEFAULT, "sigaction"));
3324     if (os_sigaction == NULL) return;
3325   }
3326 
3327   os_sigaction(sig, (struct sigaction*)NULL, &act);
3328 
3329   address thisHandler = (act.sa_flags & SA_SIGINFO)
3330     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3331     : CAST_FROM_FN_PTR(address, act.sa_handler);
3332 
3333   switch(sig) {
3334   case SIGSEGV:
3335   case SIGBUS:
3336   case SIGFPE:
3337   case SIGPIPE:
3338   case SIGILL:
3339   case SIGXFSZ:
3340     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)javaSignalHandler);
3341     break;
3342 
3343   case SHUTDOWN1_SIGNAL:
3344   case SHUTDOWN2_SIGNAL:
3345   case SHUTDOWN3_SIGNAL:
3346   case BREAK_SIGNAL:
3347     jvmHandler = (address)user_handler();
3348     break;
3349 
3350   default:
3351     if (sig == SR_signum) {
3352       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3353     } else {
3354       return;
3355     }
3356     break;
3357   }
3358 
3359   if (thisHandler != jvmHandler) {
3360     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3361     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3362     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3363     // No need to check this sig any longer
3364     sigaddset(&check_signal_done, sig);
3365     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3366     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3367       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3368                     exception_name(sig, buf, O_BUFLEN));
3369     }
3370   } else if (os::Aix::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Aix::get_our_sigflags(sig)) {
3371     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3372     tty->print("expected:");
3373     os::Posix::print_sa_flags(tty, os::Aix::get_our_sigflags(sig));
3374     tty->cr();
3375     tty->print("  found:");
3376     os::Posix::print_sa_flags(tty, act.sa_flags);
3377     tty->cr();
3378     // No need to check this sig any longer
3379     sigaddset(&check_signal_done, sig);
3380   }
3381 
3382   // Dump all the signal
3383   if (sigismember(&check_signal_done, sig)) {
3384     print_signal_handlers(tty, buf, O_BUFLEN);
3385   }
3386 }
3387 
3388 // To install functions for atexit system call
3389 extern "C" {
3390   static void perfMemory_exit_helper() {
3391     perfMemory_exit();
3392   }
3393 }
3394 
3395 // This is called _before_ the most of global arguments have been parsed.
3396 void os::init(void) {
3397   // This is basic, we want to know if that ever changes.
3398   // (Shared memory boundary is supposed to be a 256M aligned.)
3399   assert(SHMLBA == ((uint64_t)0x10000000ULL)/*256M*/, "unexpected");
3400 
3401   // Record process break at startup.
3402   g_brk_at_startup = (address) ::sbrk(0);
3403   assert(g_brk_at_startup != (address) -1, "sbrk failed");
3404 
3405   // First off, we need to know whether we run on AIX or PASE, and
3406   // the OS level we run on.
3407   os::Aix::initialize_os_info();
3408 
3409   // Scan environment (SPEC1170 behaviour, etc).
3410   os::Aix::scan_environment();
3411 
3412   // Probe multipage support.
3413   query_multipage_support();
3414 
3415   // Act like we only have one page size by eliminating corner cases which
3416   // we did not support very well anyway.
3417   // We have two input conditions:
3418   // 1) Data segment page size. This is controlled by linker setting (datapsize) on the
3419   //    launcher, and/or by LDR_CNTRL environment variable. The latter overrules the linker
3420   //    setting.
3421   //    Data segment page size is important for us because it defines the thread stack page
3422   //    size, which is needed for guard page handling, stack banging etc.
3423   // 2) The ability to allocate 64k pages dynamically. If this is a given, java heap can
3424   //    and should be allocated with 64k pages.
3425   //
3426   // So, we do the following:
3427   // LDR_CNTRL    can_use_64K_pages_dynamically       what we do                      remarks
3428   // 4K           no                                  4K                              old systems (aix 5.2, as/400 v5r4) or new systems with AME activated
3429   // 4k           yes                                 64k (treat 4k stacks as 64k)    different loader than java and standard settings
3430   // 64k          no              --- AIX 5.2 ? ---
3431   // 64k          yes                                 64k                             new systems and standard java loader (we set datapsize=64k when linking)
3432 
3433   // We explicitly leave no option to change page size, because only upgrading would work,
3434   // not downgrading (if stack page size is 64k you cannot pretend its 4k).
3435 
3436   if (g_multipage_support.datapsize == 4*K) {
3437     // datapsize = 4K. Data segment, thread stacks are 4K paged.
3438     if (g_multipage_support.can_use_64K_pages) {
3439       // .. but we are able to use 64K pages dynamically.
3440       // This would be typical for java launchers which are not linked
3441       // with datapsize=64K (like, any other launcher but our own).
3442       //
3443       // In this case it would be smart to allocate the java heap with 64K
3444       // to get the performance benefit, and to fake 64k pages for the
3445       // data segment (when dealing with thread stacks).
3446       //
3447       // However, leave a possibility to downgrade to 4K, using
3448       // -XX:-Use64KPages.
3449       if (Use64KPages) {
3450         trcVerbose("64K page mode (faked for data segment)");
3451         Aix::_page_size = 64*K;
3452       } else {
3453         trcVerbose("4K page mode (Use64KPages=off)");
3454         Aix::_page_size = 4*K;
3455       }
3456     } else {
3457       // .. and not able to allocate 64k pages dynamically. Here, just
3458       // fall back to 4K paged mode and use mmap for everything.
3459       trcVerbose("4K page mode");
3460       Aix::_page_size = 4*K;
3461       FLAG_SET_ERGO(Use64KPages, false);
3462     }
3463   } else {
3464     // datapsize = 64k. Data segment, thread stacks are 64k paged.
3465     // This normally means that we can allocate 64k pages dynamically.
3466     // (There is one special case where this may be false: EXTSHM=on.
3467     // but we decided to not support that mode).
3468     assert0(g_multipage_support.can_use_64K_pages);
3469     Aix::_page_size = 64*K;
3470     trcVerbose("64K page mode");
3471     FLAG_SET_ERGO(Use64KPages, true);
3472   }
3473 
3474   // For now UseLargePages is just ignored.
3475   FLAG_SET_ERGO(UseLargePages, false);
3476   _page_sizes[0] = 0;
3477 
3478   // debug trace
3479   trcVerbose("os::vm_page_size %s", describe_pagesize(os::vm_page_size()));
3480 
3481   // Next, we need to initialize libo4 and libperfstat libraries.
3482   if (os::Aix::on_pase()) {
3483     os::Aix::initialize_libo4();
3484   } else {
3485     os::Aix::initialize_libperfstat();
3486   }
3487 
3488   // Reset the perfstat information provided by ODM.
3489   if (os::Aix::on_aix()) {
3490     libperfstat::perfstat_reset();
3491   }
3492 
3493   // Now initialze basic system properties. Note that for some of the values we
3494   // need libperfstat etc.
3495   os::Aix::initialize_system_info();
3496 
3497   clock_tics_per_sec = sysconf(_SC_CLK_TCK);
3498 
3499   init_random(1234567);
3500 
3501   // _main_thread points to the thread that created/loaded the JVM.
3502   Aix::_main_thread = pthread_self();
3503 
3504   initial_time_count = javaTimeNanos();
3505 
3506   os::Posix::init();
3507 }
3508 
3509 // This is called _after_ the global arguments have been parsed.
3510 jint os::init_2(void) {
3511 
3512   // This could be set after os::Posix::init() but all platforms
3513   // have to set it the same so we have to mirror Solaris.
3514   DEBUG_ONLY(os::set_mutex_init_done();)
3515 
3516   os::Posix::init_2();
3517 
3518   if (os::Aix::on_pase()) {
3519     trcVerbose("Running on PASE.");
3520   } else {
3521     trcVerbose("Running on AIX (not PASE).");
3522   }
3523 
3524   trcVerbose("processor count: %d", os::_processor_count);
3525   trcVerbose("physical memory: %lu", Aix::_physical_memory);
3526 
3527   // Initially build up the loaded dll map.
3528   LoadedLibraries::reload();
3529   if (Verbose) {
3530     trcVerbose("Loaded Libraries: ");
3531     LoadedLibraries::print(tty);
3532   }
3533 
3534   // initialize suspend/resume support - must do this before signal_sets_init()
3535   if (SR_initialize() != 0) {
3536     perror("SR_initialize failed");
3537     return JNI_ERR;
3538   }
3539 
3540   Aix::signal_sets_init();
3541   Aix::install_signal_handlers();
3542   // Initialize data for jdk.internal.misc.Signal
3543   if (!ReduceSignalUsage) {
3544     jdk_misc_signal_init();
3545   }
3546 
3547   // Check and sets minimum stack sizes against command line options
3548   if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
3549     return JNI_ERR;
3550   }
3551 
3552   if (UseNUMA) {
3553     UseNUMA = false;
3554     warning("NUMA optimizations are not available on this OS.");
3555   }
3556 
3557   if (MaxFDLimit) {
3558     // Set the number of file descriptors to max. print out error
3559     // if getrlimit/setrlimit fails but continue regardless.
3560     struct rlimit nbr_files;
3561     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3562     if (status != 0) {
3563       log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3564     } else {
3565       nbr_files.rlim_cur = nbr_files.rlim_max;
3566       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3567       if (status != 0) {
3568         log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3569       }
3570     }
3571   }
3572 
3573   if (PerfAllowAtExitRegistration) {
3574     // Only register atexit functions if PerfAllowAtExitRegistration is set.
3575     // At exit functions can be delayed until process exit time, which
3576     // can be problematic for embedded VM situations. Embedded VMs should
3577     // call DestroyJavaVM() to assure that VM resources are released.
3578 
3579     // Note: perfMemory_exit_helper atexit function may be removed in
3580     // the future if the appropriate cleanup code can be added to the
3581     // VM_Exit VMOperation's doit method.
3582     if (atexit(perfMemory_exit_helper) != 0) {
3583       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
3584     }
3585   }
3586 
3587   // initialize thread priority policy
3588   prio_init();
3589 
3590   return JNI_OK;
3591 }
3592 
3593 int os::active_processor_count() {
3594   // User has overridden the number of active processors
3595   if (ActiveProcessorCount > 0) {
3596     log_trace(os)("active_processor_count: "
3597                   "active processor count set by user : %d",
3598                   ActiveProcessorCount);
3599     return ActiveProcessorCount;
3600   }
3601 
3602   int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
3603   assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check");
3604   return online_cpus;
3605 }
3606 
3607 void os::set_native_thread_name(const char *name) {
3608   // Not yet implemented.
3609   return;
3610 }
3611 
3612 bool os::bind_to_processor(uint processor_id) {
3613   // Not yet implemented.
3614   return false;
3615 }
3616 
3617 void os::SuspendedThreadTask::internal_do_task() {
3618   if (do_suspend(_thread->osthread())) {
3619     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3620     do_task(context);
3621     do_resume(_thread->osthread());
3622   }
3623 }
3624 
3625 ////////////////////////////////////////////////////////////////////////////////
3626 // debug support
3627 
3628 bool os::find(address addr, outputStream* st) {
3629 
3630   st->print(PTR_FORMAT ": ", addr);
3631 
3632   loaded_module_t lm;
3633   if (LoadedLibraries::find_for_text_address(addr, &lm) != NULL ||
3634       LoadedLibraries::find_for_data_address(addr, &lm) != NULL) {
3635     st->print_cr("%s", lm.path);
3636     return true;
3637   }
3638 
3639   return false;
3640 }
3641 
3642 ////////////////////////////////////////////////////////////////////////////////
3643 // misc
3644 
3645 // This does not do anything on Aix. This is basically a hook for being
3646 // able to use structured exception handling (thread-local exception filters)
3647 // on, e.g., Win32.
3648 void
3649 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
3650                          JavaCallArguments* args, Thread* thread) {
3651   f(value, method, args, thread);
3652 }
3653 
3654 void os::print_statistics() {
3655 }
3656 
3657 bool os::message_box(const char* title, const char* message) {
3658   int i;
3659   fdStream err(defaultStream::error_fd());
3660   for (i = 0; i < 78; i++) err.print_raw("=");
3661   err.cr();
3662   err.print_raw_cr(title);
3663   for (i = 0; i < 78; i++) err.print_raw("-");
3664   err.cr();
3665   err.print_raw_cr(message);
3666   for (i = 0; i < 78; i++) err.print_raw("=");
3667   err.cr();
3668 
3669   char buf[16];
3670   // Prevent process from exiting upon "read error" without consuming all CPU
3671   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3672 
3673   return buf[0] == 'y' || buf[0] == 'Y';
3674 }
3675 
3676 // Is a (classpath) directory empty?
3677 bool os::dir_is_empty(const char* path) {
3678   DIR *dir = NULL;
3679   struct dirent *ptr;
3680 
3681   dir = opendir(path);
3682   if (dir == NULL) return true;
3683 
3684   /* Scan the directory */
3685   bool result = true;
3686   while (result && (ptr = readdir(dir)) != NULL) {
3687     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3688       result = false;
3689     }
3690   }
3691   closedir(dir);
3692   return result;
3693 }
3694 
3695 // This code originates from JDK's sysOpen and open64_w
3696 // from src/solaris/hpi/src/system_md.c
3697 
3698 int os::open(const char *path, int oflag, int mode) {
3699 
3700   if (strlen(path) > MAX_PATH - 1) {
3701     errno = ENAMETOOLONG;
3702     return -1;
3703   }
3704   // AIX 7.X now supports O_CLOEXEC too, like modern Linux; but we have to be careful, see
3705   // IV90804: OPENING A FILE IN AFS WITH O_CLOEXEC FAILS WITH AN EINVAL ERROR APPLIES TO AIX 7100-04 17/04/14 PTF PECHANGE
3706   int oflag_with_o_cloexec = oflag | O_CLOEXEC;
3707 
3708   int fd = ::open64(path, oflag_with_o_cloexec, mode);
3709   if (fd == -1) {
3710     // we might fail in the open call when O_CLOEXEC is set, so try again without (see IV90804)
3711     fd = ::open64(path, oflag, mode);
3712     if (fd == -1) {
3713       return -1;
3714     }
3715   }
3716 
3717   // If the open succeeded, the file might still be a directory.
3718   {
3719     struct stat64 buf64;
3720     int ret = ::fstat64(fd, &buf64);
3721     int st_mode = buf64.st_mode;
3722 
3723     if (ret != -1) {
3724       if ((st_mode & S_IFMT) == S_IFDIR) {
3725         errno = EISDIR;
3726         ::close(fd);
3727         return -1;
3728       }
3729     } else {
3730       ::close(fd);
3731       return -1;
3732     }
3733   }
3734 
3735   // All file descriptors that are opened in the JVM and not
3736   // specifically destined for a subprocess should have the
3737   // close-on-exec flag set. If we don't set it, then careless 3rd
3738   // party native code might fork and exec without closing all
3739   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3740   // UNIXProcess.c), and this in turn might:
3741   //
3742   // - cause end-of-file to fail to be detected on some file
3743   //   descriptors, resulting in mysterious hangs, or
3744   //
3745   // - might cause an fopen in the subprocess to fail on a system
3746   //   suffering from bug 1085341.
3747 
3748   // Validate that the use of the O_CLOEXEC flag on open above worked.
3749   static sig_atomic_t O_CLOEXEC_is_known_to_work = 0;
3750   if (O_CLOEXEC_is_known_to_work == 0) {
3751     int flags = ::fcntl(fd, F_GETFD);
3752     if (flags != -1) {
3753       if ((flags & FD_CLOEXEC) != 0) {
3754         O_CLOEXEC_is_known_to_work = 1;
3755       } else { // it does not work
3756         ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3757         O_CLOEXEC_is_known_to_work = -1;
3758       }
3759     }
3760   } else if (O_CLOEXEC_is_known_to_work == -1) {
3761     int flags = ::fcntl(fd, F_GETFD);
3762     if (flags != -1) {
3763       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3764     }
3765   }
3766 
3767   return fd;
3768 }
3769 
3770 // create binary file, rewriting existing file if required
3771 int os::create_binary_file(const char* path, bool rewrite_existing) {
3772   int oflags = O_WRONLY | O_CREAT;
3773   if (!rewrite_existing) {
3774     oflags |= O_EXCL;
3775   }
3776   return ::open64(path, oflags, S_IREAD | S_IWRITE);
3777 }
3778 
3779 // return current position of file pointer
3780 jlong os::current_file_offset(int fd) {
3781   return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
3782 }
3783 
3784 // move file pointer to the specified offset
3785 jlong os::seek_to_file_offset(int fd, jlong offset) {
3786   return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
3787 }
3788 
3789 // This code originates from JDK's sysAvailable
3790 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3791 
3792 int os::available(int fd, jlong *bytes) {
3793   jlong cur, end;
3794   int mode;
3795   struct stat64 buf64;
3796 
3797   if (::fstat64(fd, &buf64) >= 0) {
3798     mode = buf64.st_mode;
3799     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3800       int n;
3801       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3802         *bytes = n;
3803         return 1;
3804       }
3805     }
3806   }
3807   if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
3808     return 0;
3809   } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
3810     return 0;
3811   } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
3812     return 0;
3813   }
3814   *bytes = end - cur;
3815   return 1;
3816 }
3817 
3818 // Map a block of memory.
3819 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3820                         char *addr, size_t bytes, bool read_only,
3821                         bool allow_exec) {
3822   int prot;
3823   int flags = MAP_PRIVATE;
3824 
3825   if (read_only) {
3826     prot = PROT_READ;
3827     flags = MAP_SHARED;
3828   } else {
3829     prot = PROT_READ | PROT_WRITE;
3830     flags = MAP_PRIVATE;
3831   }
3832 
3833   if (allow_exec) {
3834     prot |= PROT_EXEC;
3835   }
3836 
3837   if (addr != NULL) {
3838     flags |= MAP_FIXED;
3839   }
3840 
3841   // Allow anonymous mappings if 'fd' is -1.
3842   if (fd == -1) {
3843     flags |= MAP_ANONYMOUS;
3844   }
3845 
3846   char* mapped_address = (char*)::mmap(addr, (size_t)bytes, prot, flags,
3847                                      fd, file_offset);
3848   if (mapped_address == MAP_FAILED) {
3849     return NULL;
3850   }
3851   return mapped_address;
3852 }
3853 
3854 // Remap a block of memory.
3855 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3856                           char *addr, size_t bytes, bool read_only,
3857                           bool allow_exec) {
3858   // same as map_memory() on this OS
3859   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3860                         allow_exec);
3861 }
3862 
3863 // Unmap a block of memory.
3864 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3865   return munmap(addr, bytes) == 0;
3866 }
3867 
3868 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3869 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3870 // of a thread.
3871 //
3872 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3873 // the fast estimate available on the platform.
3874 
3875 jlong os::current_thread_cpu_time() {
3876   // return user + sys since the cost is the same
3877   const jlong n = os::thread_cpu_time(Thread::current(), true /* user + sys */);
3878   assert(n >= 0, "negative CPU time");
3879   return n;
3880 }
3881 
3882 jlong os::thread_cpu_time(Thread* thread) {
3883   // consistent with what current_thread_cpu_time() returns
3884   const jlong n = os::thread_cpu_time(thread, true /* user + sys */);
3885   assert(n >= 0, "negative CPU time");
3886   return n;
3887 }
3888 
3889 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3890   const jlong n = os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3891   assert(n >= 0, "negative CPU time");
3892   return n;
3893 }
3894 
3895 static bool thread_cpu_time_unchecked(Thread* thread, jlong* p_sys_time, jlong* p_user_time) {
3896   bool error = false;
3897 
3898   jlong sys_time = 0;
3899   jlong user_time = 0;
3900 
3901   // Reimplemented using getthrds64().
3902   //
3903   // Works like this:
3904   // For the thread in question, get the kernel thread id. Then get the
3905   // kernel thread statistics using that id.
3906   //
3907   // This only works of course when no pthread scheduling is used,
3908   // i.e. there is a 1:1 relationship to kernel threads.
3909   // On AIX, see AIXTHREAD_SCOPE variable.
3910 
3911   pthread_t pthtid = thread->osthread()->pthread_id();
3912 
3913   // retrieve kernel thread id for the pthread:
3914   tid64_t tid = 0;
3915   struct __pthrdsinfo pinfo;
3916   // I just love those otherworldly IBM APIs which force me to hand down
3917   // dummy buffers for stuff I dont care for...
3918   char dummy[1];
3919   int dummy_size = sizeof(dummy);
3920   if (pthread_getthrds_np(&pthtid, PTHRDSINFO_QUERY_TID, &pinfo, sizeof(pinfo),
3921                           dummy, &dummy_size) == 0) {
3922     tid = pinfo.__pi_tid;
3923   } else {
3924     tty->print_cr("pthread_getthrds_np failed.");
3925     error = true;
3926   }
3927 
3928   // retrieve kernel timing info for that kernel thread
3929   if (!error) {
3930     struct thrdentry64 thrdentry;
3931     if (getthrds64(getpid(), &thrdentry, sizeof(thrdentry), &tid, 1) == 1) {
3932       sys_time = thrdentry.ti_ru.ru_stime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_stime.tv_usec * 1000LL;
3933       user_time = thrdentry.ti_ru.ru_utime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_utime.tv_usec * 1000LL;
3934     } else {
3935       tty->print_cr("pthread_getthrds_np failed.");
3936       error = true;
3937     }
3938   }
3939 
3940   if (p_sys_time) {
3941     *p_sys_time = sys_time;
3942   }
3943 
3944   if (p_user_time) {
3945     *p_user_time = user_time;
3946   }
3947 
3948   if (error) {
3949     return false;
3950   }
3951 
3952   return true;
3953 }
3954 
3955 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3956   jlong sys_time;
3957   jlong user_time;
3958 
3959   if (!thread_cpu_time_unchecked(thread, &sys_time, &user_time)) {
3960     return -1;
3961   }
3962 
3963   return user_sys_cpu_time ? sys_time + user_time : user_time;
3964 }
3965 
3966 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3967   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3968   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3969   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3970   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3971 }
3972 
3973 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3974   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3975   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3976   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3977   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3978 }
3979 
3980 bool os::is_thread_cpu_time_supported() {
3981   return true;
3982 }
3983 
3984 // System loadavg support. Returns -1 if load average cannot be obtained.
3985 // For now just return the system wide load average (no processor sets).
3986 int os::loadavg(double values[], int nelem) {
3987 
3988   guarantee(nelem >= 0 && nelem <= 3, "argument error");
3989   guarantee(values, "argument error");
3990 
3991   if (os::Aix::on_pase()) {
3992 
3993     // AS/400 PASE: use libo4 porting library
3994     double v[3] = { 0.0, 0.0, 0.0 };
3995 
3996     if (libo4::get_load_avg(v, v + 1, v + 2)) {
3997       for (int i = 0; i < nelem; i ++) {
3998         values[i] = v[i];
3999       }
4000       return nelem;
4001     } else {
4002       return -1;
4003     }
4004 
4005   } else {
4006 
4007     // AIX: use libperfstat
4008     libperfstat::cpuinfo_t ci;
4009     if (libperfstat::get_cpuinfo(&ci)) {
4010       for (int i = 0; i < nelem; i++) {
4011         values[i] = ci.loadavg[i];
4012       }
4013     } else {
4014       return -1;
4015     }
4016     return nelem;
4017   }
4018 }
4019 
4020 void os::pause() {
4021   char filename[MAX_PATH];
4022   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4023     jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
4024   } else {
4025     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4026   }
4027 
4028   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4029   if (fd != -1) {
4030     struct stat buf;
4031     ::close(fd);
4032     while (::stat(filename, &buf) == 0) {
4033       (void)::poll(NULL, 0, 100);
4034     }
4035   } else {
4036     trcVerbose("Could not open pause file '%s', continuing immediately.", filename);
4037   }
4038 }
4039 
4040 bool os::is_primordial_thread(void) {
4041   if (pthread_self() == (pthread_t)1) {
4042     return true;
4043   } else {
4044     return false;
4045   }
4046 }
4047 
4048 // OS recognitions (PASE/AIX, OS level) call this before calling any
4049 // one of Aix::on_pase(), Aix::os_version() static
4050 void os::Aix::initialize_os_info() {
4051 
4052   assert(_on_pase == -1 && _os_version == 0, "already called.");
4053 
4054   struct utsname uts;
4055   memset(&uts, 0, sizeof(uts));
4056   strcpy(uts.sysname, "?");
4057   if (::uname(&uts) == -1) {
4058     trcVerbose("uname failed (%d)", errno);
4059     guarantee(0, "Could not determine whether we run on AIX or PASE");
4060   } else {
4061     trcVerbose("uname says: sysname \"%s\" version \"%s\" release \"%s\" "
4062                "node \"%s\" machine \"%s\"\n",
4063                uts.sysname, uts.version, uts.release, uts.nodename, uts.machine);
4064     const int major = atoi(uts.version);
4065     assert(major > 0, "invalid OS version");
4066     const int minor = atoi(uts.release);
4067     assert(minor > 0, "invalid OS release");
4068     _os_version = (major << 24) | (minor << 16);
4069     char ver_str[20] = {0};
4070     const char* name_str = "unknown OS";
4071     if (strcmp(uts.sysname, "OS400") == 0) {
4072       // We run on AS/400 PASE. We do not support versions older than V5R4M0.
4073       _on_pase = 1;
4074       if (os_version_short() < 0x0504) {
4075         trcVerbose("OS/400 releases older than V5R4M0 not supported.");
4076         assert(false, "OS/400 release too old.");
4077       }
4078       name_str = "OS/400 (pase)";
4079       jio_snprintf(ver_str, sizeof(ver_str), "%u.%u", major, minor);
4080     } else if (strcmp(uts.sysname, "AIX") == 0) {
4081       // We run on AIX. We do not support versions older than AIX 7.1.
4082       _on_pase = 0;
4083       // Determine detailed AIX version: Version, Release, Modification, Fix Level.
4084       odmWrapper::determine_os_kernel_version(&_os_version);
4085       if (os_version_short() < 0x0701) {
4086         trcVerbose("AIX releases older than AIX 7.1 are not supported.");
4087         assert(false, "AIX release too old.");
4088       }
4089       name_str = "AIX";
4090       jio_snprintf(ver_str, sizeof(ver_str), "%u.%u.%u.%u",
4091                    major, minor, (_os_version >> 8) & 0xFF, _os_version & 0xFF);
4092     } else {
4093       assert(false, "%s", name_str);
4094     }
4095     trcVerbose("We run on %s %s", name_str, ver_str);
4096   }
4097 
4098   guarantee(_on_pase != -1 && _os_version, "Could not determine AIX/OS400 release");
4099 } // end: os::Aix::initialize_os_info()
4100 
4101 // Scan environment for important settings which might effect the VM.
4102 // Trace out settings. Warn about invalid settings and/or correct them.
4103 //
4104 // Must run after os::Aix::initialue_os_info().
4105 void os::Aix::scan_environment() {
4106 
4107   char* p;
4108   int rc;
4109 
4110   // Warn explicity if EXTSHM=ON is used. That switch changes how
4111   // System V shared memory behaves. One effect is that page size of
4112   // shared memory cannot be change dynamically, effectivly preventing
4113   // large pages from working.
4114   // This switch was needed on AIX 32bit, but on AIX 64bit the general
4115   // recommendation is (in OSS notes) to switch it off.
4116   p = ::getenv("EXTSHM");
4117   trcVerbose("EXTSHM=%s.", p ? p : "<unset>");
4118   if (p && strcasecmp(p, "ON") == 0) {
4119     _extshm = 1;
4120     trcVerbose("*** Unsupported mode! Please remove EXTSHM from your environment! ***");
4121     if (!AllowExtshm) {
4122       // We allow under certain conditions the user to continue. However, we want this
4123       // to be a fatal error by default. On certain AIX systems, leaving EXTSHM=ON means
4124       // that the VM is not able to allocate 64k pages for the heap.
4125       // We do not want to run with reduced performance.
4126       vm_exit_during_initialization("EXTSHM is ON. Please remove EXTSHM from your environment.");
4127     }
4128   } else {
4129     _extshm = 0;
4130   }
4131 
4132   // SPEC1170 behaviour: will change the behaviour of a number of POSIX APIs.
4133   // Not tested, not supported.
4134   //
4135   // Note that it might be worth the trouble to test and to require it, if only to
4136   // get useful return codes for mprotect.
4137   //
4138   // Note: Setting XPG_SUS_ENV in the process is too late. Must be set earlier (before
4139   // exec() ? before loading the libjvm ? ....)
4140   p = ::getenv("XPG_SUS_ENV");
4141   trcVerbose("XPG_SUS_ENV=%s.", p ? p : "<unset>");
4142   if (p && strcmp(p, "ON") == 0) {
4143     _xpg_sus_mode = 1;
4144     trcVerbose("Unsupported setting: XPG_SUS_ENV=ON");
4145     // This is not supported. Worst of all, it changes behaviour of mmap MAP_FIXED to
4146     // clobber address ranges. If we ever want to support that, we have to do some
4147     // testing first.
4148     guarantee(false, "XPG_SUS_ENV=ON not supported");
4149   } else {
4150     _xpg_sus_mode = 0;
4151   }
4152 
4153   if (os::Aix::on_pase()) {
4154     p = ::getenv("QIBM_MULTI_THREADED");
4155     trcVerbose("QIBM_MULTI_THREADED=%s.", p ? p : "<unset>");
4156   }
4157 
4158   p = ::getenv("LDR_CNTRL");
4159   trcVerbose("LDR_CNTRL=%s.", p ? p : "<unset>");
4160   if (os::Aix::on_pase() && os::Aix::os_version_short() == 0x0701) {
4161     if (p && ::strstr(p, "TEXTPSIZE")) {
4162       trcVerbose("*** WARNING - LDR_CNTRL contains TEXTPSIZE. "
4163         "you may experience hangs or crashes on OS/400 V7R1.");
4164     }
4165   }
4166 
4167   p = ::getenv("AIXTHREAD_GUARDPAGES");
4168   trcVerbose("AIXTHREAD_GUARDPAGES=%s.", p ? p : "<unset>");
4169 
4170 } // end: os::Aix::scan_environment()
4171 
4172 // PASE: initialize the libo4 library (PASE porting library).
4173 void os::Aix::initialize_libo4() {
4174   guarantee(os::Aix::on_pase(), "OS/400 only.");
4175   if (!libo4::init()) {
4176     trcVerbose("libo4 initialization failed.");
4177     assert(false, "libo4 initialization failed");
4178   } else {
4179     trcVerbose("libo4 initialized.");
4180   }
4181 }
4182 
4183 // AIX: initialize the libperfstat library.
4184 void os::Aix::initialize_libperfstat() {
4185   assert(os::Aix::on_aix(), "AIX only");
4186   if (!libperfstat::init()) {
4187     trcVerbose("libperfstat initialization failed.");
4188     assert(false, "libperfstat initialization failed");
4189   } else {
4190     trcVerbose("libperfstat initialized.");
4191   }
4192 }
4193 
4194 /////////////////////////////////////////////////////////////////////////////
4195 // thread stack
4196 
4197 // Get the current stack base from the OS (actually, the pthread library).
4198 // Note: usually not page aligned.
4199 address os::current_stack_base() {
4200   AixMisc::stackbounds_t bounds;
4201   bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
4202   guarantee(rc, "Unable to retrieve stack bounds.");
4203   return bounds.base;
4204 }
4205 
4206 // Get the current stack size from the OS (actually, the pthread library).
4207 // Returned size is such that (base - size) is always aligned to page size.
4208 size_t os::current_stack_size() {
4209   AixMisc::stackbounds_t bounds;
4210   bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
4211   guarantee(rc, "Unable to retrieve stack bounds.");
4212   // Align the returned stack size such that the stack low address
4213   // is aligned to page size (Note: base is usually not and we do not care).
4214   // We need to do this because caller code will assume stack low address is
4215   // page aligned and will place guard pages without checking.
4216   address low = bounds.base - bounds.size;
4217   address low_aligned = (address)align_up(low, os::vm_page_size());
4218   size_t s = bounds.base - low_aligned;
4219   return s;
4220 }
4221 
4222 extern char** environ;
4223 
4224 // Run the specified command in a separate process. Return its exit value,
4225 // or -1 on failure (e.g. can't fork a new process).
4226 // Unlike system(), this function can be called from signal handler. It
4227 // doesn't block SIGINT et al.
4228 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
4229   char* argv[4] = { (char*)"sh", (char*)"-c", cmd, NULL};
4230 
4231   pid_t pid = fork();
4232 
4233   if (pid < 0) {
4234     // fork failed
4235     return -1;
4236 
4237   } else if (pid == 0) {
4238     // child process
4239 
4240     // Try to be consistent with system(), which uses "/usr/bin/sh" on AIX.
4241     execve("/usr/bin/sh", argv, environ);
4242 
4243     // execve failed
4244     _exit(-1);
4245 
4246   } else {
4247     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4248     // care about the actual exit code, for now.
4249 
4250     int status;
4251 
4252     // Wait for the child process to exit. This returns immediately if
4253     // the child has already exited. */
4254     while (waitpid(pid, &status, 0) < 0) {
4255       switch (errno) {
4256         case ECHILD: return 0;
4257         case EINTR: break;
4258         default: return -1;
4259       }
4260     }
4261 
4262     if (WIFEXITED(status)) {
4263       // The child exited normally; get its exit code.
4264       return WEXITSTATUS(status);
4265     } else if (WIFSIGNALED(status)) {
4266       // The child exited because of a signal.
4267       // The best value to return is 0x80 + signal number,
4268       // because that is what all Unix shells do, and because
4269       // it allows callers to distinguish between process exit and
4270       // process death by signal.
4271       return 0x80 + WTERMSIG(status);
4272     } else {
4273       // Unknown exit code; pass it through.
4274       return status;
4275     }
4276   }
4277   return -1;
4278 }
4279 
4280 // Get the default path to the core file
4281 // Returns the length of the string
4282 int os::get_core_path(char* buffer, size_t bufferSize) {
4283   const char* p = get_current_directory(buffer, bufferSize);
4284 
4285   if (p == NULL) {
4286     assert(p != NULL, "failed to get current directory");
4287     return 0;
4288   }
4289 
4290   jio_snprintf(buffer, bufferSize, "%s/core or core.%d",
4291                                                p, current_process_id());
4292 
4293   return strlen(buffer);
4294 }
4295 
4296 #ifndef PRODUCT
4297 void TestReserveMemorySpecial_test() {
4298   // No tests available for this platform
4299 }
4300 #endif
4301 
4302 bool os::start_debugging(char *buf, int buflen) {
4303   int len = (int)strlen(buf);
4304   char *p = &buf[len];
4305 
4306   jio_snprintf(p, buflen -len,
4307                  "\n\n"
4308                  "Do you want to debug the problem?\n\n"
4309                  "To debug, run 'dbx -a %d'; then switch to thread tid " INTX_FORMAT ", k-tid " INTX_FORMAT "\n"
4310                  "Enter 'yes' to launch dbx automatically (PATH must include dbx)\n"
4311                  "Otherwise, press RETURN to abort...",
4312                  os::current_process_id(),
4313                  os::current_thread_id(), thread_self());
4314 
4315   bool yes = os::message_box("Unexpected Error", buf);
4316 
4317   if (yes) {
4318     // yes, user asked VM to launch debugger
4319     jio_snprintf(buf, buflen, "dbx -a %d", os::current_process_id());
4320 
4321     os::fork_and_exec(buf);
4322     yes = false;
4323   }
4324   return yes;
4325 }
4326 
4327 static inline time_t get_mtime(const char* filename) {
4328   struct stat st;
4329   int ret = os::stat(filename, &st);
4330   assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
4331   return st.st_mtime;
4332 }
4333 
4334 int os::compare_file_modified_times(const char* file1, const char* file2) {
4335   time_t t1 = get_mtime(file1);
4336   time_t t2 = get_mtime(file2);
4337   return t1 - t2;
4338 }
4339 
4340 bool os::supports_map_sync() {
4341   return false;
4342 }