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     ::abort(); // dump core
1184   }
1185 
1186   ::exit(1);
1187 }
1188 
1189 // Die immediately, no exit hook, no abort hook, no cleanup.
1190 // Dump a core file, if possible, for debugging.
1191 void os::die() {
1192   if (TestUnresponsiveErrorHandler && !CreateCoredumpOnCrash) {
1193     // For TimeoutInErrorHandlingTest.java, we just kill the VM
1194     // and don't take the time to generate a core file.
1195     os::signal_raise(SIGKILL);
1196   } else {
1197     ::abort();
1198   }
1199 }
1200 
1201 intx os::current_thread_id() {
1202   return (intx)pthread_self();
1203 }
1204 
1205 int os::current_process_id() {
1206   return getpid();
1207 }
1208 
1209 // DLL functions
1210 
1211 const char* os::dll_file_extension() { return ".so"; }
1212 
1213 // This must be hard coded because it's the system's temporary
1214 // directory not the java application's temp directory, ala java.io.tmpdir.
1215 const char* os::get_temp_directory() { return "/tmp"; }
1216 
1217 // Check if addr is inside libjvm.so.
1218 bool os::address_is_in_vm(address addr) {
1219 
1220   // Input could be a real pc or a function pointer literal. The latter
1221   // would be a function descriptor residing in the data segment of a module.
1222   loaded_module_t lm;
1223   if (LoadedLibraries::find_for_text_address(addr, &lm) != NULL) {
1224     return lm.is_in_vm;
1225   } else if (LoadedLibraries::find_for_data_address(addr, &lm) != NULL) {
1226     return lm.is_in_vm;
1227   } else {
1228     return false;
1229   }
1230 
1231 }
1232 
1233 // Resolve an AIX function descriptor literal to a code pointer.
1234 // If the input is a valid code pointer to a text segment of a loaded module,
1235 //   it is returned unchanged.
1236 // If the input is a valid AIX function descriptor, it is resolved to the
1237 //   code entry point.
1238 // If the input is neither a valid function descriptor nor a valid code pointer,
1239 //   NULL is returned.
1240 static address resolve_function_descriptor_to_code_pointer(address p) {
1241 
1242   if (LoadedLibraries::find_for_text_address(p, NULL) != NULL) {
1243     // It is a real code pointer.
1244     return p;
1245   } else if (LoadedLibraries::find_for_data_address(p, NULL) != NULL) {
1246     // Pointer to data segment, potential function descriptor.
1247     address code_entry = (address)(((FunctionDescriptor*)p)->entry());
1248     if (LoadedLibraries::find_for_text_address(code_entry, NULL) != NULL) {
1249       // It is a function descriptor.
1250       return code_entry;
1251     }
1252   }
1253 
1254   return NULL;
1255 }
1256 
1257 bool os::dll_address_to_function_name(address addr, char *buf,
1258                                       int buflen, int *offset,
1259                                       bool demangle) {
1260   if (offset) {
1261     *offset = -1;
1262   }
1263   // Buf is not optional, but offset is optional.
1264   assert(buf != NULL, "sanity check");
1265   buf[0] = '\0';
1266 
1267   // Resolve function ptr literals first.
1268   addr = resolve_function_descriptor_to_code_pointer(addr);
1269   if (!addr) {
1270     return false;
1271   }
1272 
1273   return AixSymbols::get_function_name(addr, buf, buflen, offset, NULL, demangle);
1274 }
1275 
1276 bool os::dll_address_to_library_name(address addr, char* buf,
1277                                      int buflen, int* offset) {
1278   if (offset) {
1279     *offset = -1;
1280   }
1281   // Buf is not optional, but offset is optional.
1282   assert(buf != NULL, "sanity check");
1283   buf[0] = '\0';
1284 
1285   // Resolve function ptr literals first.
1286   addr = resolve_function_descriptor_to_code_pointer(addr);
1287   if (!addr) {
1288     return false;
1289   }
1290 
1291   return AixSymbols::get_module_name(addr, buf, buflen);
1292 }
1293 
1294 // Loads .dll/.so and in case of error it checks if .dll/.so was built
1295 // for the same architecture as Hotspot is running on.
1296 void *os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1297 
1298   log_info(os)("attempting shared library load of %s", filename);
1299 
1300   if (ebuf && ebuflen > 0) {
1301     ebuf[0] = '\0';
1302     ebuf[ebuflen - 1] = '\0';
1303   }
1304 
1305   if (!filename || strlen(filename) == 0) {
1306     ::strncpy(ebuf, "dll_load: empty filename specified", ebuflen - 1);
1307     return NULL;
1308   }
1309 
1310   // RTLD_LAZY is currently not implemented. The dl is loaded immediately with all its dependants.
1311   void * result= ::dlopen(filename, RTLD_LAZY);
1312   if (result != NULL) {
1313     Events::log(NULL, "Loaded shared library %s", filename);
1314     // Reload dll cache. Don't do this in signal handling.
1315     LoadedLibraries::reload();
1316     log_info(os)("shared library load of %s was successful", filename);
1317     return result;
1318   } else {
1319     // error analysis when dlopen fails
1320     const char* error_report = ::dlerror();
1321     if (error_report == NULL) {
1322       error_report = "dlerror returned no error description";
1323     }
1324     if (ebuf != NULL && ebuflen > 0) {
1325       snprintf(ebuf, ebuflen - 1, "%s, LIBPATH=%s, LD_LIBRARY_PATH=%s : %s",
1326                filename, ::getenv("LIBPATH"), ::getenv("LD_LIBRARY_PATH"), error_report);
1327     }
1328     Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
1329     log_info(os)("shared library load of %s failed, %s", filename, error_report);
1330   }
1331   return NULL;
1332 }
1333 
1334 void* os::dll_lookup(void* handle, const char* name) {
1335   void* res = dlsym(handle, name);
1336   return res;
1337 }
1338 
1339 void* os::get_default_process_handle() {
1340   return (void*)::dlopen(NULL, RTLD_LAZY);
1341 }
1342 
1343 void os::print_dll_info(outputStream *st) {
1344   st->print_cr("Dynamic libraries:");
1345   LoadedLibraries::print(st);
1346 }
1347 
1348 void os::get_summary_os_info(char* buf, size_t buflen) {
1349   // There might be something more readable than uname results for AIX.
1350   struct utsname name;
1351   uname(&name);
1352   snprintf(buf, buflen, "%s %s", name.release, name.version);
1353 }
1354 
1355 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1356   // Not yet implemented.
1357   return 0;
1358 }
1359 
1360 void os::print_os_info_brief(outputStream* st) {
1361   uint32_t ver = os::Aix::os_version();
1362   st->print_cr("AIX kernel version %u.%u.%u.%u",
1363                (ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
1364 
1365   os::Posix::print_uname_info(st);
1366 
1367   // Linux uses print_libversion_info(st); here.
1368 }
1369 
1370 void os::print_os_info(outputStream* st) {
1371   st->print("OS:");
1372 
1373   os::Posix::print_uname_info(st);
1374 
1375   uint32_t ver = os::Aix::os_version();
1376   st->print_cr("AIX kernel version %u.%u.%u.%u",
1377                (ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
1378 
1379   os::Posix::print_uptime_info(st);
1380 
1381   os::Posix::print_rlimit_info(st);
1382 
1383   os::Posix::print_load_average(st);
1384 
1385   // _SC_THREAD_THREADS_MAX is the maximum number of threads within a process.
1386   long tmax = sysconf(_SC_THREAD_THREADS_MAX);
1387   st->print_cr("maximum #threads within a process:%ld", tmax);
1388 
1389   // print wpar info
1390   libperfstat::wparinfo_t wi;
1391   if (libperfstat::get_wparinfo(&wi)) {
1392     st->print_cr("wpar info");
1393     st->print_cr("name: %s", wi.name);
1394     st->print_cr("id:   %d", wi.wpar_id);
1395     st->print_cr("type: %s", (wi.app_wpar ? "application" : "system"));
1396   }
1397 
1398   VM_Version::print_platform_virtualization_info(st);
1399 }
1400 
1401 void os::print_memory_info(outputStream* st) {
1402 
1403   st->print_cr("Memory:");
1404 
1405   st->print_cr("  Base page size (sysconf _SC_PAGESIZE):  %s",
1406     describe_pagesize(g_multipage_support.pagesize));
1407   st->print_cr("  Data page size (C-Heap, bss, etc):      %s",
1408     describe_pagesize(g_multipage_support.datapsize));
1409   st->print_cr("  Text page size:                         %s",
1410     describe_pagesize(g_multipage_support.textpsize));
1411   st->print_cr("  Thread stack page size (pthread):       %s",
1412     describe_pagesize(g_multipage_support.pthr_stack_pagesize));
1413   st->print_cr("  Default shared memory page size:        %s",
1414     describe_pagesize(g_multipage_support.shmpsize));
1415   st->print_cr("  Can use 64K pages dynamically with shared memory:  %s",
1416     (g_multipage_support.can_use_64K_pages ? "yes" :"no"));
1417   st->print_cr("  Can use 16M pages dynamically with shared memory: %s",
1418     (g_multipage_support.can_use_16M_pages ? "yes" :"no"));
1419   st->print_cr("  Multipage error: %d",
1420     g_multipage_support.error);
1421   st->cr();
1422   st->print_cr("  os::vm_page_size:       %s", describe_pagesize(os::vm_page_size()));
1423 
1424   // print out LDR_CNTRL because it affects the default page sizes
1425   const char* const ldr_cntrl = ::getenv("LDR_CNTRL");
1426   st->print_cr("  LDR_CNTRL=%s.", ldr_cntrl ? ldr_cntrl : "<unset>");
1427 
1428   // Print out EXTSHM because it is an unsupported setting.
1429   const char* const extshm = ::getenv("EXTSHM");
1430   st->print_cr("  EXTSHM=%s.", extshm ? extshm : "<unset>");
1431   if ( (strcmp(extshm, "on") == 0) || (strcmp(extshm, "ON") == 0) ) {
1432     st->print_cr("  *** Unsupported! Please remove EXTSHM from your environment! ***");
1433   }
1434 
1435   // Print out AIXTHREAD_GUARDPAGES because it affects the size of pthread stacks.
1436   const char* const aixthread_guardpages = ::getenv("AIXTHREAD_GUARDPAGES");
1437   st->print_cr("  AIXTHREAD_GUARDPAGES=%s.",
1438       aixthread_guardpages ? aixthread_guardpages : "<unset>");
1439   st->cr();
1440 
1441   os::Aix::meminfo_t mi;
1442   if (os::Aix::get_meminfo(&mi)) {
1443     if (os::Aix::on_aix()) {
1444       st->print_cr("physical total : " SIZE_FORMAT, mi.real_total);
1445       st->print_cr("physical free  : " SIZE_FORMAT, mi.real_free);
1446       st->print_cr("swap total     : " SIZE_FORMAT, mi.pgsp_total);
1447       st->print_cr("swap free      : " SIZE_FORMAT, mi.pgsp_free);
1448     } else {
1449       // PASE - Numbers are result of QWCRSSTS; they mean:
1450       // real_total: Sum of all system pools
1451       // real_free: always 0
1452       // pgsp_total: we take the size of the system ASP
1453       // pgsp_free: size of system ASP times percentage of system ASP unused
1454       st->print_cr("physical total     : " SIZE_FORMAT, mi.real_total);
1455       st->print_cr("system asp total   : " SIZE_FORMAT, mi.pgsp_total);
1456       st->print_cr("%% system asp used : %.2f",
1457         mi.pgsp_total ? (100.0f * (mi.pgsp_total - mi.pgsp_free) / mi.pgsp_total) : -1.0f);
1458     }
1459   }
1460   st->cr();
1461 
1462   // Print program break.
1463   st->print_cr("Program break at VM startup: " PTR_FORMAT ".", p2i(g_brk_at_startup));
1464   address brk_now = (address)::sbrk(0);
1465   if (brk_now != (address)-1) {
1466     st->print_cr("Program break now          : " PTR_FORMAT " (distance: " SIZE_FORMAT "k).",
1467                  p2i(brk_now), (size_t)((brk_now - g_brk_at_startup) / K));
1468   }
1469   st->print_cr("MaxExpectedDataSegmentSize    : " SIZE_FORMAT "k.", MaxExpectedDataSegmentSize / K);
1470   st->cr();
1471 
1472   // Print segments allocated with os::reserve_memory.
1473   st->print_cr("internal virtual memory regions used by vm:");
1474   vmembk_print_on(st);
1475 }
1476 
1477 // Get a string for the cpuinfo that is a summary of the cpu type
1478 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1479   // read _system_configuration.version
1480   switch (_system_configuration.version) {
1481   case PV_9:
1482     strncpy(buf, "Power PC 9", buflen);
1483     break;
1484   case PV_8:
1485     strncpy(buf, "Power PC 8", buflen);
1486     break;
1487   case PV_7:
1488     strncpy(buf, "Power PC 7", buflen);
1489     break;
1490   case PV_6_1:
1491     strncpy(buf, "Power PC 6 DD1.x", buflen);
1492     break;
1493   case PV_6:
1494     strncpy(buf, "Power PC 6", buflen);
1495     break;
1496   case PV_5:
1497     strncpy(buf, "Power PC 5", buflen);
1498     break;
1499   case PV_5_2:
1500     strncpy(buf, "Power PC 5_2", buflen);
1501     break;
1502   case PV_5_3:
1503     strncpy(buf, "Power PC 5_3", buflen);
1504     break;
1505   case PV_5_Compat:
1506     strncpy(buf, "PV_5_Compat", buflen);
1507     break;
1508   case PV_6_Compat:
1509     strncpy(buf, "PV_6_Compat", buflen);
1510     break;
1511   case PV_7_Compat:
1512     strncpy(buf, "PV_7_Compat", buflen);
1513     break;
1514   case PV_8_Compat:
1515     strncpy(buf, "PV_8_Compat", buflen);
1516     break;
1517   case PV_9_Compat:
1518     strncpy(buf, "PV_9_Compat", buflen);
1519     break;
1520   default:
1521     strncpy(buf, "unknown", buflen);
1522   }
1523 }
1524 
1525 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1526   // Nothing to do beyond of what os::print_cpu_info() does.
1527 }
1528 
1529 static void print_signal_handler(outputStream* st, int sig,
1530                                  char* buf, size_t buflen);
1531 
1532 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1533   st->print_cr("Signal Handlers:");
1534   print_signal_handler(st, SIGSEGV, buf, buflen);
1535   print_signal_handler(st, SIGBUS , buf, buflen);
1536   print_signal_handler(st, SIGFPE , buf, buflen);
1537   print_signal_handler(st, SIGPIPE, buf, buflen);
1538   print_signal_handler(st, SIGXFSZ, buf, buflen);
1539   print_signal_handler(st, SIGILL , buf, buflen);
1540   print_signal_handler(st, SR_signum, buf, buflen);
1541   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1542   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1543   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1544   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1545   print_signal_handler(st, SIGTRAP, buf, buflen);
1546   // We also want to know if someone else adds a SIGDANGER handler because
1547   // that will interfere with OOM killling.
1548   print_signal_handler(st, SIGDANGER, buf, buflen);
1549 }
1550 
1551 static char saved_jvm_path[MAXPATHLEN] = {0};
1552 
1553 // Find the full path to the current module, libjvm.so.
1554 void os::jvm_path(char *buf, jint buflen) {
1555   // Error checking.
1556   if (buflen < MAXPATHLEN) {
1557     assert(false, "must use a large-enough buffer");
1558     buf[0] = '\0';
1559     return;
1560   }
1561   // Lazy resolve the path to current module.
1562   if (saved_jvm_path[0] != 0) {
1563     strcpy(buf, saved_jvm_path);
1564     return;
1565   }
1566 
1567   Dl_info dlinfo;
1568   int ret = dladdr(CAST_FROM_FN_PTR(void *, os::jvm_path), &dlinfo);
1569   assert(ret != 0, "cannot locate libjvm");
1570   char* rp = os::Posix::realpath((char *)dlinfo.dli_fname, buf, buflen);
1571   assert(rp != NULL, "error in realpath(): maybe the 'path' argument is too long?");
1572 
1573   if (Arguments::sun_java_launcher_is_altjvm()) {
1574     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1575     // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
1576     // If "/jre/lib/" appears at the right place in the string, then
1577     // assume we are installed in a JDK and we're done. Otherwise, check
1578     // for a JAVA_HOME environment variable and fix up the path so it
1579     // looks like libjvm.so is installed there (append a fake suffix
1580     // hotspot/libjvm.so).
1581     const char *p = buf + strlen(buf) - 1;
1582     for (int count = 0; p > buf && count < 4; ++count) {
1583       for (--p; p > buf && *p != '/'; --p)
1584         /* empty */ ;
1585     }
1586 
1587     if (strncmp(p, "/jre/lib/", 9) != 0) {
1588       // Look for JAVA_HOME in the environment.
1589       char* java_home_var = ::getenv("JAVA_HOME");
1590       if (java_home_var != NULL && java_home_var[0] != 0) {
1591         char* jrelib_p;
1592         int len;
1593 
1594         // Check the current module name "libjvm.so".
1595         p = strrchr(buf, '/');
1596         if (p == NULL) {
1597           return;
1598         }
1599         assert(strstr(p, "/libjvm") == p, "invalid library name");
1600 
1601         rp = os::Posix::realpath(java_home_var, buf, buflen);
1602         if (rp == NULL) {
1603           return;
1604         }
1605 
1606         // determine if this is a legacy image or modules image
1607         // modules image doesn't have "jre" subdirectory
1608         len = strlen(buf);
1609         assert(len < buflen, "Ran out of buffer room");
1610         jrelib_p = buf + len;
1611         snprintf(jrelib_p, buflen-len, "/jre/lib");
1612         if (0 != access(buf, F_OK)) {
1613           snprintf(jrelib_p, buflen-len, "/lib");
1614         }
1615 
1616         if (0 == access(buf, F_OK)) {
1617           // Use current module name "libjvm.so"
1618           len = strlen(buf);
1619           snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
1620         } else {
1621           // Go back to path of .so
1622           rp = os::Posix::realpath((char *)dlinfo.dli_fname, buf, buflen);
1623           if (rp == NULL) {
1624             return;
1625           }
1626         }
1627       }
1628     }
1629   }
1630 
1631   strncpy(saved_jvm_path, buf, sizeof(saved_jvm_path));
1632   saved_jvm_path[sizeof(saved_jvm_path) - 1] = '\0';
1633 }
1634 
1635 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1636   // no prefix required, not even "_"
1637 }
1638 
1639 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1640   // no suffix required
1641 }
1642 
1643 ////////////////////////////////////////////////////////////////////////////////
1644 // sun.misc.Signal support
1645 
1646 static void
1647 UserHandler(int sig, void *siginfo, void *context) {
1648   // Ctrl-C is pressed during error reporting, likely because the error
1649   // handler fails to abort. Let VM die immediately.
1650   if (sig == SIGINT && VMError::is_error_reported()) {
1651     os::die();
1652   }
1653 
1654   os::signal_notify(sig);
1655 }
1656 
1657 void* os::user_handler() {
1658   return CAST_FROM_FN_PTR(void*, UserHandler);
1659 }
1660 
1661 extern "C" {
1662   typedef void (*sa_handler_t)(int);
1663   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1664 }
1665 
1666 void* os::signal(int signal_number, void* handler) {
1667   struct sigaction sigAct, oldSigAct;
1668 
1669   sigfillset(&(sigAct.sa_mask));
1670 
1671   // Do not block out synchronous signals in the signal handler.
1672   // Blocking synchronous signals only makes sense if you can really
1673   // be sure that those signals won't happen during signal handling,
1674   // when the blocking applies. Normal signal handlers are lean and
1675   // do not cause signals. But our signal handlers tend to be "risky"
1676   // - secondary SIGSEGV, SIGILL, SIGBUS' may and do happen.
1677   // On AIX, PASE there was a case where a SIGSEGV happened, followed
1678   // by a SIGILL, which was blocked due to the signal mask. The process
1679   // just hung forever. Better to crash from a secondary signal than to hang.
1680   sigdelset(&(sigAct.sa_mask), SIGSEGV);
1681   sigdelset(&(sigAct.sa_mask), SIGBUS);
1682   sigdelset(&(sigAct.sa_mask), SIGILL);
1683   sigdelset(&(sigAct.sa_mask), SIGFPE);
1684   sigdelset(&(sigAct.sa_mask), SIGTRAP);
1685 
1686   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1687 
1688   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1689 
1690   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1691     // -1 means registration failed
1692     return (void *)-1;
1693   }
1694 
1695   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1696 }
1697 
1698 void os::signal_raise(int signal_number) {
1699   ::raise(signal_number);
1700 }
1701 
1702 //
1703 // The following code is moved from os.cpp for making this
1704 // code platform specific, which it is by its very nature.
1705 //
1706 
1707 // Will be modified when max signal is changed to be dynamic
1708 int os::sigexitnum_pd() {
1709   return NSIG;
1710 }
1711 
1712 // a counter for each possible signal value
1713 static volatile jint pending_signals[NSIG+1] = { 0 };
1714 
1715 // Wrapper functions for: sem_init(), sem_post(), sem_wait()
1716 // On AIX, we use sem_init(), sem_post(), sem_wait()
1717 // On Pase, we need to use msem_lock() and msem_unlock(), because Posix Semaphores
1718 // do not seem to work at all on PASE (unimplemented, will cause SIGILL).
1719 // Note that just using msem_.. APIs for both PASE and AIX is not an option either, as
1720 // on AIX, msem_..() calls are suspected of causing problems.
1721 static sem_t sig_sem;
1722 static msemaphore* p_sig_msem = 0;
1723 
1724 static void local_sem_init() {
1725   if (os::Aix::on_aix()) {
1726     int rc = ::sem_init(&sig_sem, 0, 0);
1727     guarantee(rc != -1, "sem_init failed");
1728   } else {
1729     // Memory semaphores must live in shared mem.
1730     guarantee0(p_sig_msem == NULL);
1731     p_sig_msem = (msemaphore*)os::reserve_memory(sizeof(msemaphore), NULL);
1732     guarantee(p_sig_msem, "Cannot allocate memory for memory semaphore");
1733     guarantee(::msem_init(p_sig_msem, 0) == p_sig_msem, "msem_init failed");
1734   }
1735 }
1736 
1737 static void local_sem_post() {
1738   static bool warn_only_once = false;
1739   if (os::Aix::on_aix()) {
1740     int rc = ::sem_post(&sig_sem);
1741     if (rc == -1 && !warn_only_once) {
1742       trcVerbose("sem_post failed (errno = %d, %s)", errno, os::errno_name(errno));
1743       warn_only_once = true;
1744     }
1745   } else {
1746     guarantee0(p_sig_msem != NULL);
1747     int rc = ::msem_unlock(p_sig_msem, 0);
1748     if (rc == -1 && !warn_only_once) {
1749       trcVerbose("msem_unlock failed (errno = %d, %s)", errno, os::errno_name(errno));
1750       warn_only_once = true;
1751     }
1752   }
1753 }
1754 
1755 static void local_sem_wait() {
1756   static bool warn_only_once = false;
1757   if (os::Aix::on_aix()) {
1758     int rc = ::sem_wait(&sig_sem);
1759     if (rc == -1 && !warn_only_once) {
1760       trcVerbose("sem_wait failed (errno = %d, %s)", errno, os::errno_name(errno));
1761       warn_only_once = true;
1762     }
1763   } else {
1764     guarantee0(p_sig_msem != NULL); // must init before use
1765     int rc = ::msem_lock(p_sig_msem, 0);
1766     if (rc == -1 && !warn_only_once) {
1767       trcVerbose("msem_lock failed (errno = %d, %s)", errno, os::errno_name(errno));
1768       warn_only_once = true;
1769     }
1770   }
1771 }
1772 
1773 static void jdk_misc_signal_init() {
1774   // Initialize signal structures
1775   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1776 
1777   // Initialize signal semaphore
1778   local_sem_init();
1779 }
1780 
1781 void os::signal_notify(int sig) {
1782   Atomic::inc(&pending_signals[sig]);
1783   local_sem_post();
1784 }
1785 
1786 static int check_pending_signals() {
1787   for (;;) {
1788     for (int i = 0; i < NSIG + 1; i++) {
1789       jint n = pending_signals[i];
1790       if (n > 0 && n == Atomic::cmpxchg(&pending_signals[i], n, n - 1)) {
1791         return i;
1792       }
1793     }
1794     JavaThread *thread = JavaThread::current();
1795     ThreadBlockInVM tbivm(thread);
1796 
1797     bool threadIsSuspended;
1798     do {
1799       thread->set_suspend_equivalent();
1800       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1801 
1802       local_sem_wait();
1803 
1804       // were we externally suspended while we were waiting?
1805       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1806       if (threadIsSuspended) {
1807         //
1808         // The semaphore has been incremented, but while we were waiting
1809         // another thread suspended us. We don't want to continue running
1810         // while suspended because that would surprise the thread that
1811         // suspended us.
1812         //
1813 
1814         local_sem_post();
1815 
1816         thread->java_suspend_self();
1817       }
1818     } while (threadIsSuspended);
1819   }
1820 }
1821 
1822 int os::signal_wait() {
1823   return check_pending_signals();
1824 }
1825 
1826 ////////////////////////////////////////////////////////////////////////////////
1827 // Virtual Memory
1828 
1829 // We need to keep small simple bookkeeping for os::reserve_memory and friends.
1830 
1831 #define VMEM_MAPPED  1
1832 #define VMEM_SHMATED 2
1833 
1834 struct vmembk_t {
1835   int type;         // 1 - mmap, 2 - shmat
1836   char* addr;
1837   size_t size;      // Real size, may be larger than usersize.
1838   size_t pagesize;  // page size of area
1839   vmembk_t* next;
1840 
1841   bool contains_addr(char* p) const {
1842     return p >= addr && p < (addr + size);
1843   }
1844 
1845   bool contains_range(char* p, size_t s) const {
1846     return contains_addr(p) && contains_addr(p + s - 1);
1847   }
1848 
1849   void print_on(outputStream* os) const {
1850     os->print("[" PTR_FORMAT " - " PTR_FORMAT "] (" UINTX_FORMAT
1851       " bytes, %d %s pages), %s",
1852       addr, addr + size - 1, size, size / pagesize, describe_pagesize(pagesize),
1853       (type == VMEM_SHMATED ? "shmat" : "mmap")
1854     );
1855   }
1856 
1857   // Check that range is a sub range of memory block (or equal to memory block);
1858   // also check that range is fully page aligned to the page size if the block.
1859   void assert_is_valid_subrange(char* p, size_t s) const {
1860     if (!contains_range(p, s)) {
1861       trcVerbose("[" PTR_FORMAT " - " PTR_FORMAT "] is not a sub "
1862               "range of [" PTR_FORMAT " - " PTR_FORMAT "].",
1863               p2i(p), p2i(p + s), p2i(addr), p2i(addr + size));
1864       guarantee0(false);
1865     }
1866     if (!is_aligned_to(p, pagesize) || !is_aligned_to(p + s, pagesize)) {
1867       trcVerbose("range [" PTR_FORMAT " - " PTR_FORMAT "] is not"
1868               " aligned to pagesize (%lu)", p2i(p), p2i(p + s), (unsigned long) pagesize);
1869       guarantee0(false);
1870     }
1871   }
1872 };
1873 
1874 static struct {
1875   vmembk_t* first;
1876   MiscUtils::CritSect cs;
1877 } vmem;
1878 
1879 static void vmembk_add(char* addr, size_t size, size_t pagesize, int type) {
1880   vmembk_t* p = (vmembk_t*) ::malloc(sizeof(vmembk_t));
1881   assert0(p);
1882   if (p) {
1883     MiscUtils::AutoCritSect lck(&vmem.cs);
1884     p->addr = addr; p->size = size;
1885     p->pagesize = pagesize;
1886     p->type = type;
1887     p->next = vmem.first;
1888     vmem.first = p;
1889   }
1890 }
1891 
1892 static vmembk_t* vmembk_find(char* addr) {
1893   MiscUtils::AutoCritSect lck(&vmem.cs);
1894   for (vmembk_t* p = vmem.first; p; p = p->next) {
1895     if (p->addr <= addr && (p->addr + p->size) > addr) {
1896       return p;
1897     }
1898   }
1899   return NULL;
1900 }
1901 
1902 static void vmembk_remove(vmembk_t* p0) {
1903   MiscUtils::AutoCritSect lck(&vmem.cs);
1904   assert0(p0);
1905   assert0(vmem.first); // List should not be empty.
1906   for (vmembk_t** pp = &(vmem.first); *pp; pp = &((*pp)->next)) {
1907     if (*pp == p0) {
1908       *pp = p0->next;
1909       ::free(p0);
1910       return;
1911     }
1912   }
1913   assert0(false); // Not found?
1914 }
1915 
1916 static void vmembk_print_on(outputStream* os) {
1917   MiscUtils::AutoCritSect lck(&vmem.cs);
1918   for (vmembk_t* vmi = vmem.first; vmi; vmi = vmi->next) {
1919     vmi->print_on(os);
1920     os->cr();
1921   }
1922 }
1923 
1924 // Reserve and attach a section of System V memory.
1925 // If <requested_addr> is not NULL, function will attempt to attach the memory at the given
1926 // address. Failing that, it will attach the memory anywhere.
1927 // If <requested_addr> is NULL, function will attach the memory anywhere.
1928 //
1929 // <alignment_hint> is being ignored by this function. It is very probable however that the
1930 // alignment requirements are met anyway, because shmat() attaches at 256M boundaries.
1931 // Should this be not enogh, we can put more work into it.
1932 static char* reserve_shmated_memory (
1933   size_t bytes,
1934   char* requested_addr,
1935   size_t alignment_hint) {
1936 
1937   trcVerbose("reserve_shmated_memory " UINTX_FORMAT " bytes, wishaddress "
1938     PTR_FORMAT ", alignment_hint " UINTX_FORMAT "...",
1939     bytes, p2i(requested_addr), alignment_hint);
1940 
1941   // Either give me wish address or wish alignment but not both.
1942   assert0(!(requested_addr != NULL && alignment_hint != 0));
1943 
1944   // We must prevent anyone from attaching too close to the
1945   // BRK because that may cause malloc OOM.
1946   if (requested_addr != NULL && is_close_to_brk((address)requested_addr)) {
1947     trcVerbose("Wish address " PTR_FORMAT " is too close to the BRK segment. "
1948       "Will attach anywhere.", p2i(requested_addr));
1949     // Act like the OS refused to attach there.
1950     requested_addr = NULL;
1951   }
1952 
1953   // For old AS/400's (V5R4 and older) we should not even be here - System V shared memory is not
1954   // really supported (max size 4GB), so reserve_mmapped_memory should have been used instead.
1955   if (os::Aix::on_pase_V5R4_or_older()) {
1956     ShouldNotReachHere();
1957   }
1958 
1959   // Align size of shm up to 64K to avoid errors if we later try to change the page size.
1960   const size_t size = align_up(bytes, 64*K);
1961 
1962   // Reserve the shared segment.
1963   int shmid = shmget(IPC_PRIVATE, size, IPC_CREAT | S_IRUSR | S_IWUSR);
1964   if (shmid == -1) {
1965     trcVerbose("shmget(.., " UINTX_FORMAT ", ..) failed (errno: %d).", size, errno);
1966     return NULL;
1967   }
1968 
1969   // Important note:
1970   // It is very important that we, upon leaving this function, do not leave a shm segment alive.
1971   // We must right after attaching it remove it from the system. System V shm segments are global and
1972   // survive the process.
1973   // So, from here on: Do not assert, do not return, until we have called shmctl(IPC_RMID) (A).
1974 
1975   struct shmid_ds shmbuf;
1976   memset(&shmbuf, 0, sizeof(shmbuf));
1977   shmbuf.shm_pagesize = 64*K;
1978   if (shmctl(shmid, SHM_PAGESIZE, &shmbuf) != 0) {
1979     trcVerbose("Failed to set page size (need " UINTX_FORMAT " 64K pages) - shmctl failed with %d.",
1980                size / (64*K), errno);
1981     // I want to know if this ever happens.
1982     assert(false, "failed to set page size for shmat");
1983   }
1984 
1985   // Now attach the shared segment.
1986   // Note that I attach with SHM_RND - which means that the requested address is rounded down, if
1987   // needed, to the next lowest segment boundary. Otherwise the attach would fail if the address
1988   // were not a segment boundary.
1989   char* const addr = (char*) shmat(shmid, requested_addr, SHM_RND);
1990   const int errno_shmat = errno;
1991 
1992   // (A) Right after shmat and before handing shmat errors delete the shm segment.
1993   if (::shmctl(shmid, IPC_RMID, NULL) == -1) {
1994     trcVerbose("shmctl(%u, IPC_RMID) failed (%d)\n", shmid, errno);
1995     assert(false, "failed to remove shared memory segment!");
1996   }
1997 
1998   // Handle shmat error. If we failed to attach, just return.
1999   if (addr == (char*)-1) {
2000     trcVerbose("Failed to attach segment at " PTR_FORMAT " (%d).", p2i(requested_addr), errno_shmat);
2001     return NULL;
2002   }
2003 
2004   // Just for info: query the real page size. In case setting the page size did not
2005   // work (see above), the system may have given us something other then 4K (LDR_CNTRL).
2006   const size_t real_pagesize = os::Aix::query_pagesize(addr);
2007   if (real_pagesize != shmbuf.shm_pagesize) {
2008     trcVerbose("pagesize is, surprisingly, " SIZE_FORMAT, real_pagesize);
2009   }
2010 
2011   if (addr) {
2012     trcVerbose("shm-allocated " PTR_FORMAT " .. " PTR_FORMAT " (" UINTX_FORMAT " bytes, " UINTX_FORMAT " %s pages)",
2013       p2i(addr), p2i(addr + size - 1), size, size/real_pagesize, describe_pagesize(real_pagesize));
2014   } else {
2015     if (requested_addr != NULL) {
2016       trcVerbose("failed to shm-allocate " UINTX_FORMAT " bytes at with address " PTR_FORMAT ".", size, p2i(requested_addr));
2017     } else {
2018       trcVerbose("failed to shm-allocate " UINTX_FORMAT " bytes at any address.", size);
2019     }
2020   }
2021 
2022   // book-keeping
2023   vmembk_add(addr, size, real_pagesize, VMEM_SHMATED);
2024   assert0(is_aligned_to(addr, os::vm_page_size()));
2025 
2026   return addr;
2027 }
2028 
2029 static bool release_shmated_memory(char* addr, size_t size) {
2030 
2031   trcVerbose("release_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2032     p2i(addr), p2i(addr + size - 1));
2033 
2034   bool rc = false;
2035 
2036   // TODO: is there a way to verify shm size without doing bookkeeping?
2037   if (::shmdt(addr) != 0) {
2038     trcVerbose("error (%d).", errno);
2039   } else {
2040     trcVerbose("ok.");
2041     rc = true;
2042   }
2043   return rc;
2044 }
2045 
2046 static bool uncommit_shmated_memory(char* addr, size_t size) {
2047   trcVerbose("uncommit_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2048     p2i(addr), p2i(addr + size - 1));
2049 
2050   const bool rc = my_disclaim64(addr, size);
2051 
2052   if (!rc) {
2053     trcVerbose("my_disclaim64(" PTR_FORMAT ", " UINTX_FORMAT ") failed.\n", p2i(addr), size);
2054     return false;
2055   }
2056   return true;
2057 }
2058 
2059 ////////////////////////////////  mmap-based routines /////////////////////////////////
2060 
2061 // Reserve memory via mmap.
2062 // If <requested_addr> is given, an attempt is made to attach at the given address.
2063 // Failing that, memory is allocated at any address.
2064 // If <alignment_hint> is given and <requested_addr> is NULL, an attempt is made to
2065 // allocate at an address aligned with the given alignment. Failing that, memory
2066 // is aligned anywhere.
2067 static char* reserve_mmaped_memory(size_t bytes, char* requested_addr, size_t alignment_hint) {
2068   trcVerbose("reserve_mmaped_memory " UINTX_FORMAT " bytes, wishaddress " PTR_FORMAT ", "
2069     "alignment_hint " UINTX_FORMAT "...",
2070     bytes, p2i(requested_addr), alignment_hint);
2071 
2072   // If a wish address is given, but not aligned to 4K page boundary, mmap will fail.
2073   if (requested_addr && !is_aligned_to(requested_addr, os::vm_page_size()) != 0) {
2074     trcVerbose("Wish address " PTR_FORMAT " not aligned to page boundary.", p2i(requested_addr));
2075     return NULL;
2076   }
2077 
2078   // We must prevent anyone from attaching too close to the
2079   // BRK because that may cause malloc OOM.
2080   if (requested_addr != NULL && is_close_to_brk((address)requested_addr)) {
2081     trcVerbose("Wish address " PTR_FORMAT " is too close to the BRK segment. "
2082       "Will attach anywhere.", p2i(requested_addr));
2083     // Act like the OS refused to attach there.
2084     requested_addr = NULL;
2085   }
2086 
2087   // Specify one or the other but not both.
2088   assert0(!(requested_addr != NULL && alignment_hint > 0));
2089 
2090   // In 64K mode, we claim the global page size (os::vm_page_size())
2091   // is 64K. This is one of the few points where that illusion may
2092   // break, because mmap() will always return memory aligned to 4K. So
2093   // we must ensure we only ever return memory aligned to 64k.
2094   if (alignment_hint) {
2095     alignment_hint = lcm(alignment_hint, os::vm_page_size());
2096   } else {
2097     alignment_hint = os::vm_page_size();
2098   }
2099 
2100   // Size shall always be a multiple of os::vm_page_size (esp. in 64K mode).
2101   const size_t size = align_up(bytes, os::vm_page_size());
2102 
2103   // alignment: Allocate memory large enough to include an aligned range of the right size and
2104   // cut off the leading and trailing waste pages.
2105   assert0(alignment_hint != 0 && is_aligned_to(alignment_hint, os::vm_page_size())); // see above
2106   const size_t extra_size = size + alignment_hint;
2107 
2108   // Note: MAP_SHARED (instead of MAP_PRIVATE) needed to be able to
2109   // later use msync(MS_INVALIDATE) (see os::uncommit_memory).
2110   int flags = MAP_ANONYMOUS | MAP_SHARED;
2111 
2112   // MAP_FIXED is needed to enforce requested_addr - manpage is vague about what
2113   // it means if wishaddress is given but MAP_FIXED is not set.
2114   //
2115   // Important! Behaviour differs depending on whether SPEC1170 mode is active or not.
2116   // SPEC1170 mode active: behaviour like POSIX, MAP_FIXED will clobber existing mappings.
2117   // SPEC1170 mode not active: behaviour, unlike POSIX, is that no existing mappings will
2118   // get clobbered.
2119   if (requested_addr != NULL) {
2120     if (!os::Aix::xpg_sus_mode()) {  // not SPEC1170 Behaviour
2121       flags |= MAP_FIXED;
2122     }
2123   }
2124 
2125   char* addr = (char*)::mmap(requested_addr, extra_size,
2126       PROT_READ|PROT_WRITE|PROT_EXEC, flags, -1, 0);
2127 
2128   if (addr == MAP_FAILED) {
2129     trcVerbose("mmap(" PTR_FORMAT ", " UINTX_FORMAT ", ..) failed (%d)", p2i(requested_addr), size, errno);
2130     return NULL;
2131   }
2132 
2133   // Handle alignment.
2134   char* const addr_aligned = align_up(addr, alignment_hint);
2135   const size_t waste_pre = addr_aligned - addr;
2136   char* const addr_aligned_end = addr_aligned + size;
2137   const size_t waste_post = extra_size - waste_pre - size;
2138   if (waste_pre > 0) {
2139     ::munmap(addr, waste_pre);
2140   }
2141   if (waste_post > 0) {
2142     ::munmap(addr_aligned_end, waste_post);
2143   }
2144   addr = addr_aligned;
2145 
2146   if (addr) {
2147     trcVerbose("mmap-allocated " PTR_FORMAT " .. " PTR_FORMAT " (" UINTX_FORMAT " bytes)",
2148       p2i(addr), p2i(addr + bytes), bytes);
2149   } else {
2150     if (requested_addr != NULL) {
2151       trcVerbose("failed to mmap-allocate " UINTX_FORMAT " bytes at wish address " PTR_FORMAT ".", bytes, p2i(requested_addr));
2152     } else {
2153       trcVerbose("failed to mmap-allocate " UINTX_FORMAT " bytes at any address.", bytes);
2154     }
2155   }
2156 
2157   // bookkeeping
2158   vmembk_add(addr, size, 4*K, VMEM_MAPPED);
2159 
2160   // Test alignment, see above.
2161   assert0(is_aligned_to(addr, os::vm_page_size()));
2162 
2163   return addr;
2164 }
2165 
2166 static bool release_mmaped_memory(char* addr, size_t size) {
2167   assert0(is_aligned_to(addr, os::vm_page_size()));
2168   assert0(is_aligned_to(size, os::vm_page_size()));
2169 
2170   trcVerbose("release_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2171     p2i(addr), p2i(addr + size - 1));
2172   bool rc = false;
2173 
2174   if (::munmap(addr, size) != 0) {
2175     trcVerbose("failed (%d)\n", errno);
2176     rc = false;
2177   } else {
2178     trcVerbose("ok.");
2179     rc = true;
2180   }
2181 
2182   return rc;
2183 }
2184 
2185 static bool uncommit_mmaped_memory(char* addr, size_t size) {
2186 
2187   assert0(is_aligned_to(addr, os::vm_page_size()));
2188   assert0(is_aligned_to(size, os::vm_page_size()));
2189 
2190   trcVerbose("uncommit_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2191     p2i(addr), p2i(addr + size - 1));
2192   bool rc = false;
2193 
2194   // Uncommit mmap memory with msync MS_INVALIDATE.
2195   if (::msync(addr, size, MS_INVALIDATE) != 0) {
2196     trcVerbose("failed (%d)\n", errno);
2197     rc = false;
2198   } else {
2199     trcVerbose("ok.");
2200     rc = true;
2201   }
2202 
2203   return rc;
2204 }
2205 
2206 int os::vm_page_size() {
2207   // Seems redundant as all get out.
2208   assert(os::Aix::page_size() != -1, "must call os::init");
2209   return os::Aix::page_size();
2210 }
2211 
2212 // Aix allocates memory by pages.
2213 int os::vm_allocation_granularity() {
2214   assert(os::Aix::page_size() != -1, "must call os::init");
2215   return os::Aix::page_size();
2216 }
2217 
2218 #ifdef PRODUCT
2219 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2220                                     int err) {
2221   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2222           ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
2223           os::errno_name(err), err);
2224 }
2225 #endif
2226 
2227 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2228                                   const char* mesg) {
2229   assert(mesg != NULL, "mesg must be specified");
2230   if (!pd_commit_memory(addr, size, exec)) {
2231     // Add extra info in product mode for vm_exit_out_of_memory():
2232     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2233     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2234   }
2235 }
2236 
2237 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2238 
2239   assert(is_aligned_to(addr, os::vm_page_size()),
2240     "addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2241     p2i(addr), os::vm_page_size());
2242   assert(is_aligned_to(size, os::vm_page_size()),
2243     "size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2244     size, os::vm_page_size());
2245 
2246   vmembk_t* const vmi = vmembk_find(addr);
2247   guarantee0(vmi);
2248   vmi->assert_is_valid_subrange(addr, size);
2249 
2250   trcVerbose("commit_memory [" PTR_FORMAT " - " PTR_FORMAT "].", p2i(addr), p2i(addr + size - 1));
2251 
2252   if (UseExplicitCommit) {
2253     // AIX commits memory on touch. So, touch all pages to be committed.
2254     for (char* p = addr; p < (addr + size); p += 4*K) {
2255       *p = '\0';
2256     }
2257   }
2258 
2259   return true;
2260 }
2261 
2262 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, bool exec) {
2263   return pd_commit_memory(addr, size, exec);
2264 }
2265 
2266 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2267                                   size_t alignment_hint, bool exec,
2268                                   const char* mesg) {
2269   // Alignment_hint is ignored on this OS.
2270   pd_commit_memory_or_exit(addr, size, exec, mesg);
2271 }
2272 
2273 bool os::pd_uncommit_memory(char* addr, size_t size) {
2274   assert(is_aligned_to(addr, os::vm_page_size()),
2275     "addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2276     p2i(addr), os::vm_page_size());
2277   assert(is_aligned_to(size, os::vm_page_size()),
2278     "size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2279     size, os::vm_page_size());
2280 
2281   // Dynamically do different things for mmap/shmat.
2282   const vmembk_t* const vmi = vmembk_find(addr);
2283   guarantee0(vmi);
2284   vmi->assert_is_valid_subrange(addr, size);
2285 
2286   if (vmi->type == VMEM_SHMATED) {
2287     return uncommit_shmated_memory(addr, size);
2288   } else {
2289     return uncommit_mmaped_memory(addr, size);
2290   }
2291 }
2292 
2293 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2294   // Do not call this; no need to commit stack pages on AIX.
2295   ShouldNotReachHere();
2296   return true;
2297 }
2298 
2299 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2300   // Do not call this; no need to commit stack pages on AIX.
2301   ShouldNotReachHere();
2302   return true;
2303 }
2304 
2305 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2306 }
2307 
2308 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2309 }
2310 
2311 void os::numa_make_global(char *addr, size_t bytes) {
2312 }
2313 
2314 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2315 }
2316 
2317 bool os::numa_topology_changed() {
2318   return false;
2319 }
2320 
2321 size_t os::numa_get_groups_num() {
2322   return 1;
2323 }
2324 
2325 int os::numa_get_group_id() {
2326   return 0;
2327 }
2328 
2329 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2330   if (size > 0) {
2331     ids[0] = 0;
2332     return 1;
2333   }
2334   return 0;
2335 }
2336 
2337 int os::numa_get_group_id_for_address(const void* address) {
2338   return 0;
2339 }
2340 
2341 bool os::get_page_info(char *start, page_info* info) {
2342   return false;
2343 }
2344 
2345 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2346   return end;
2347 }
2348 
2349 // Reserves and attaches a shared memory segment.
2350 // Will assert if a wish address is given and could not be obtained.
2351 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, size_t alignment_hint) {
2352 
2353   // All other Unices do a mmap(MAP_FIXED) if the addr is given,
2354   // thereby clobbering old mappings at that place. That is probably
2355   // not intended, never used and almost certainly an error were it
2356   // ever be used this way (to try attaching at a specified address
2357   // without clobbering old mappings an alternate API exists,
2358   // os::attempt_reserve_memory_at()).
2359   // Instead of mimicking the dangerous coding of the other platforms, here I
2360   // just ignore the request address (release) or assert(debug).
2361   assert0(requested_addr == NULL);
2362 
2363   // Always round to os::vm_page_size(), which may be larger than 4K.
2364   bytes = align_up(bytes, os::vm_page_size());
2365   const size_t alignment_hint0 =
2366     alignment_hint ? align_up(alignment_hint, os::vm_page_size()) : 0;
2367 
2368   // In 4K mode always use mmap.
2369   // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2370   if (os::vm_page_size() == 4*K) {
2371     return reserve_mmaped_memory(bytes, requested_addr, alignment_hint);
2372   } else {
2373     if (bytes >= Use64KPagesThreshold) {
2374       return reserve_shmated_memory(bytes, requested_addr, alignment_hint);
2375     } else {
2376       return reserve_mmaped_memory(bytes, requested_addr, alignment_hint);
2377     }
2378   }
2379 }
2380 
2381 bool os::pd_release_memory(char* addr, size_t size) {
2382 
2383   // Dynamically do different things for mmap/shmat.
2384   vmembk_t* const vmi = vmembk_find(addr);
2385   guarantee0(vmi);
2386 
2387   // Always round to os::vm_page_size(), which may be larger than 4K.
2388   size = align_up(size, os::vm_page_size());
2389   addr = align_up(addr, os::vm_page_size());
2390 
2391   bool rc = false;
2392   bool remove_bookkeeping = false;
2393   if (vmi->type == VMEM_SHMATED) {
2394     // For shmatted memory, we do:
2395     // - If user wants to release the whole range, release the memory (shmdt).
2396     // - If user only wants to release a partial range, uncommit (disclaim) that
2397     //   range. That way, at least, we do not use memory anymore (bust still page
2398     //   table space).
2399     vmi->assert_is_valid_subrange(addr, size);
2400     if (addr == vmi->addr && size == vmi->size) {
2401       rc = release_shmated_memory(addr, size);
2402       remove_bookkeeping = true;
2403     } else {
2404       rc = uncommit_shmated_memory(addr, size);
2405     }
2406   } else {
2407     // User may unmap partial regions but region has to be fully contained.
2408 #ifdef ASSERT
2409     vmi->assert_is_valid_subrange(addr, size);
2410 #endif
2411     rc = release_mmaped_memory(addr, size);
2412     remove_bookkeeping = true;
2413   }
2414 
2415   // update bookkeeping
2416   if (rc && remove_bookkeeping) {
2417     vmembk_remove(vmi);
2418   }
2419 
2420   return rc;
2421 }
2422 
2423 static bool checked_mprotect(char* addr, size_t size, int prot) {
2424 
2425   // Little problem here: if SPEC1170 behaviour is off, mprotect() on AIX will
2426   // not tell me if protection failed when trying to protect an un-protectable range.
2427   //
2428   // This means if the memory was allocated using shmget/shmat, protection wont work
2429   // but mprotect will still return 0:
2430   //
2431   // See http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.basetechref/doc/basetrf1/mprotect.htm
2432 
2433   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
2434   bool rc = ::mprotect(addr, size, prot) == 0 ? true : false;
2435 
2436   if (!rc) {
2437     const char* const s_errno = os::errno_name(errno);
2438     warning("mprotect(" PTR_FORMAT "-" PTR_FORMAT ", 0x%X) failed (%s).", addr, addr + size, prot, s_errno);
2439     return false;
2440   }
2441 
2442   // mprotect success check
2443   //
2444   // Mprotect said it changed the protection but can I believe it?
2445   //
2446   // To be sure I need to check the protection afterwards. Try to
2447   // read from protected memory and check whether that causes a segfault.
2448   //
2449   if (!os::Aix::xpg_sus_mode()) {
2450 
2451     if (CanUseSafeFetch32()) {
2452 
2453       const bool read_protected =
2454         (SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
2455          SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
2456 
2457       if (prot & PROT_READ) {
2458         rc = !read_protected;
2459       } else {
2460         rc = read_protected;
2461       }
2462 
2463       if (!rc) {
2464         if (os::Aix::on_pase()) {
2465           // There is an issue on older PASE systems where mprotect() will return success but the
2466           // memory will not be protected.
2467           // This has nothing to do with the problem of using mproect() on SPEC1170 incompatible
2468           // machines; we only see it rarely, when using mprotect() to protect the guard page of
2469           // a stack. It is an OS error.
2470           //
2471           // A valid strategy is just to try again. This usually works. :-/
2472 
2473           ::usleep(1000);
2474           Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
2475           if (::mprotect(addr, size, prot) == 0) {
2476             const bool read_protected_2 =
2477               (SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
2478               SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
2479             rc = true;
2480           }
2481         }
2482       }
2483     }
2484   }
2485 
2486   assert(rc == true, "mprotect failed.");
2487 
2488   return rc;
2489 }
2490 
2491 // Set protections specified
2492 bool os::protect_memory(char* addr, size_t size, ProtType prot, bool is_committed) {
2493   unsigned int p = 0;
2494   switch (prot) {
2495   case MEM_PROT_NONE: p = PROT_NONE; break;
2496   case MEM_PROT_READ: p = PROT_READ; break;
2497   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2498   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2499   default:
2500     ShouldNotReachHere();
2501   }
2502   // is_committed is unused.
2503   return checked_mprotect(addr, size, p);
2504 }
2505 
2506 bool os::guard_memory(char* addr, size_t size) {
2507   return checked_mprotect(addr, size, PROT_NONE);
2508 }
2509 
2510 bool os::unguard_memory(char* addr, size_t size) {
2511   return checked_mprotect(addr, size, PROT_READ|PROT_WRITE|PROT_EXEC);
2512 }
2513 
2514 // Large page support
2515 
2516 static size_t _large_page_size = 0;
2517 
2518 // Enable large page support if OS allows that.
2519 void os::large_page_init() {
2520   return; // Nothing to do. See query_multipage_support and friends.
2521 }
2522 
2523 char* os::pd_reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2524   fatal("os::reserve_memory_special should not be called on AIX.");
2525   return NULL;
2526 }
2527 
2528 bool os::pd_release_memory_special(char* base, size_t bytes) {
2529   fatal("os::release_memory_special should not be called on AIX.");
2530   return false;
2531 }
2532 
2533 size_t os::large_page_size() {
2534   return _large_page_size;
2535 }
2536 
2537 bool os::can_commit_large_page_memory() {
2538   // Does not matter, we do not support huge pages.
2539   return false;
2540 }
2541 
2542 bool os::can_execute_large_page_memory() {
2543   // Does not matter, we do not support huge pages.
2544   return false;
2545 }
2546 
2547 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2548   assert(file_desc >= 0, "file_desc is not valid");
2549   char* result = NULL;
2550 
2551   // Always round to os::vm_page_size(), which may be larger than 4K.
2552   bytes = align_up(bytes, os::vm_page_size());
2553   result = reserve_mmaped_memory(bytes, requested_addr, 0);
2554 
2555   if (result != NULL) {
2556     if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2557       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2558     }
2559   }
2560   return result;
2561 }
2562 
2563 // Reserve memory at an arbitrary address, only if that area is
2564 // available (and not reserved for something else).
2565 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2566   char* addr = NULL;
2567 
2568   // Always round to os::vm_page_size(), which may be larger than 4K.
2569   bytes = align_up(bytes, os::vm_page_size());
2570 
2571   // In 4K mode always use mmap.
2572   // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2573   if (os::vm_page_size() == 4*K) {
2574     return reserve_mmaped_memory(bytes, requested_addr, 0);
2575   } else {
2576     if (bytes >= Use64KPagesThreshold) {
2577       return reserve_shmated_memory(bytes, requested_addr, 0);
2578     } else {
2579       return reserve_mmaped_memory(bytes, requested_addr, 0);
2580     }
2581   }
2582 
2583   return addr;
2584 }
2585 
2586 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2587 void os::infinite_sleep() {
2588   while (true) {    // sleep forever ...
2589     ::sleep(100);   // ... 100 seconds at a time
2590   }
2591 }
2592 
2593 // Used to convert frequent JVM_Yield() to nops
2594 bool os::dont_yield() {
2595   return DontYieldALot;
2596 }
2597 
2598 void os::naked_yield() {
2599   sched_yield();
2600 }
2601 
2602 ////////////////////////////////////////////////////////////////////////////////
2603 // thread priority support
2604 
2605 // From AIX manpage to pthread_setschedparam
2606 // (see: http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?
2607 //    topic=/com.ibm.aix.basetechref/doc/basetrf1/pthread_setschedparam.htm):
2608 //
2609 // "If schedpolicy is SCHED_OTHER, then sched_priority must be in the
2610 // range from 40 to 80, where 40 is the least favored priority and 80
2611 // is the most favored."
2612 //
2613 // (Actually, I doubt this even has an impact on AIX, as we do kernel
2614 // scheduling there; however, this still leaves iSeries.)
2615 //
2616 // We use the same values for AIX and PASE.
2617 int os::java_to_os_priority[CriticalPriority + 1] = {
2618   54,             // 0 Entry should never be used
2619 
2620   55,             // 1 MinPriority
2621   55,             // 2
2622   56,             // 3
2623 
2624   56,             // 4
2625   57,             // 5 NormPriority
2626   57,             // 6
2627 
2628   58,             // 7
2629   58,             // 8
2630   59,             // 9 NearMaxPriority
2631 
2632   60,             // 10 MaxPriority
2633 
2634   60              // 11 CriticalPriority
2635 };
2636 
2637 static int prio_init() {
2638   if (ThreadPriorityPolicy == 1) {
2639     if (geteuid() != 0) {
2640       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy) && !FLAG_IS_JIMAGE_RESOURCE(ThreadPriorityPolicy)) {
2641         warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
2642                 "e.g., being the root user. If the necessary permission is not " \
2643                 "possessed, changes to priority will be silently ignored.");
2644       }
2645     }
2646   }
2647   if (UseCriticalJavaThreadPriority) {
2648     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2649   }
2650   return 0;
2651 }
2652 
2653 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2654   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2655   pthread_t thr = thread->osthread()->pthread_id();
2656   int policy = SCHED_OTHER;
2657   struct sched_param param;
2658   param.sched_priority = newpri;
2659   int ret = pthread_setschedparam(thr, policy, &param);
2660 
2661   if (ret != 0) {
2662     trcVerbose("Could not change priority for thread %d to %d (error %d, %s)",
2663         (int)thr, newpri, ret, os::errno_name(ret));
2664   }
2665   return (ret == 0) ? OS_OK : OS_ERR;
2666 }
2667 
2668 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2669   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2670     *priority_ptr = java_to_os_priority[NormPriority];
2671     return OS_OK;
2672   }
2673   pthread_t thr = thread->osthread()->pthread_id();
2674   int policy = SCHED_OTHER;
2675   struct sched_param param;
2676   int ret = pthread_getschedparam(thr, &policy, &param);
2677   *priority_ptr = param.sched_priority;
2678 
2679   return (ret == 0) ? OS_OK : OS_ERR;
2680 }
2681 
2682 ////////////////////////////////////////////////////////////////////////////////
2683 // suspend/resume support
2684 
2685 //  The low-level signal-based suspend/resume support is a remnant from the
2686 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2687 //  within hotspot. Currently used by JFR's OSThreadSampler
2688 //
2689 //  The remaining code is greatly simplified from the more general suspension
2690 //  code that used to be used.
2691 //
2692 //  The protocol is quite simple:
2693 //  - suspend:
2694 //      - sends a signal to the target thread
2695 //      - polls the suspend state of the osthread using a yield loop
2696 //      - target thread signal handler (SR_handler) sets suspend state
2697 //        and blocks in sigsuspend until continued
2698 //  - resume:
2699 //      - sets target osthread state to continue
2700 //      - sends signal to end the sigsuspend loop in the SR_handler
2701 //
2702 //  Note that the SR_lock plays no role in this suspend/resume protocol,
2703 //  but is checked for NULL in SR_handler as a thread termination indicator.
2704 //  The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
2705 //
2706 //  Note that resume_clear_context() and suspend_save_context() are needed
2707 //  by SR_handler(), so that fetch_frame_from_ucontext() works,
2708 //  which in part is used by:
2709 //    - Forte Analyzer: AsyncGetCallTrace()
2710 //    - StackBanging: get_frame_at_stack_banging_point()
2711 
2712 static void resume_clear_context(OSThread *osthread) {
2713   osthread->set_ucontext(NULL);
2714   osthread->set_siginfo(NULL);
2715 }
2716 
2717 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2718   osthread->set_ucontext(context);
2719   osthread->set_siginfo(siginfo);
2720 }
2721 
2722 //
2723 // Handler function invoked when a thread's execution is suspended or
2724 // resumed. We have to be careful that only async-safe functions are
2725 // called here (Note: most pthread functions are not async safe and
2726 // should be avoided.)
2727 //
2728 // Note: sigwait() is a more natural fit than sigsuspend() from an
2729 // interface point of view, but sigwait() prevents the signal hander
2730 // from being run. libpthread would get very confused by not having
2731 // its signal handlers run and prevents sigwait()'s use with the
2732 // mutex granting granting signal.
2733 //
2734 // Currently only ever called on the VMThread and JavaThreads (PC sampling).
2735 //
2736 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2737   // Save and restore errno to avoid confusing native code with EINTR
2738   // after sigsuspend.
2739   int old_errno = errno;
2740 
2741   Thread* thread = Thread::current_or_null_safe();
2742   assert(thread != NULL, "Missing current thread in SR_handler");
2743 
2744   // On some systems we have seen signal delivery get "stuck" until the signal
2745   // mask is changed as part of thread termination. Check that the current thread
2746   // has not already terminated (via SR_lock()) - else the following assertion
2747   // will fail because the thread is no longer a JavaThread as the ~JavaThread
2748   // destructor has completed.
2749 
2750   if (thread->SR_lock() == NULL) {
2751     return;
2752   }
2753 
2754   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2755 
2756   OSThread* osthread = thread->osthread();
2757 
2758   os::SuspendResume::State current = osthread->sr.state();
2759   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2760     suspend_save_context(osthread, siginfo, context);
2761 
2762     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2763     os::SuspendResume::State state = osthread->sr.suspended();
2764     if (state == os::SuspendResume::SR_SUSPENDED) {
2765       sigset_t suspend_set;  // signals for sigsuspend()
2766       sigemptyset(&suspend_set);
2767       // get current set of blocked signals and unblock resume signal
2768       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2769       sigdelset(&suspend_set, SR_signum);
2770 
2771       // wait here until we are resumed
2772       while (1) {
2773         sigsuspend(&suspend_set);
2774 
2775         os::SuspendResume::State result = osthread->sr.running();
2776         if (result == os::SuspendResume::SR_RUNNING) {
2777           break;
2778         }
2779       }
2780 
2781     } else if (state == os::SuspendResume::SR_RUNNING) {
2782       // request was cancelled, continue
2783     } else {
2784       ShouldNotReachHere();
2785     }
2786 
2787     resume_clear_context(osthread);
2788   } else if (current == os::SuspendResume::SR_RUNNING) {
2789     // request was cancelled, continue
2790   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2791     // ignore
2792   } else {
2793     ShouldNotReachHere();
2794   }
2795 
2796   errno = old_errno;
2797 }
2798 
2799 static int SR_initialize() {
2800   struct sigaction act;
2801   char *s;
2802   // Get signal number to use for suspend/resume
2803   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2804     int sig = ::strtol(s, 0, 10);
2805     if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
2806         sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
2807       SR_signum = sig;
2808     } else {
2809       warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2810               sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2811     }
2812   }
2813 
2814   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2815         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2816 
2817   sigemptyset(&SR_sigset);
2818   sigaddset(&SR_sigset, SR_signum);
2819 
2820   // Set up signal handler for suspend/resume.
2821   act.sa_flags = SA_RESTART|SA_SIGINFO;
2822   act.sa_handler = (void (*)(int)) SR_handler;
2823 
2824   // SR_signum is blocked by default.
2825   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2826 
2827   if (sigaction(SR_signum, &act, 0) == -1) {
2828     return -1;
2829   }
2830 
2831   // Save signal flag
2832   os::Aix::set_our_sigflags(SR_signum, act.sa_flags);
2833   return 0;
2834 }
2835 
2836 static int SR_finalize() {
2837   return 0;
2838 }
2839 
2840 static int sr_notify(OSThread* osthread) {
2841   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2842   assert_status(status == 0, status, "pthread_kill");
2843   return status;
2844 }
2845 
2846 // "Randomly" selected value for how long we want to spin
2847 // before bailing out on suspending a thread, also how often
2848 // we send a signal to a thread we want to resume
2849 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2850 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2851 
2852 // returns true on success and false on error - really an error is fatal
2853 // but this seems the normal response to library errors
2854 static bool do_suspend(OSThread* osthread) {
2855   assert(osthread->sr.is_running(), "thread should be running");
2856   // mark as suspended and send signal
2857 
2858   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2859     // failed to switch, state wasn't running?
2860     ShouldNotReachHere();
2861     return false;
2862   }
2863 
2864   if (sr_notify(osthread) != 0) {
2865     // try to cancel, switch to running
2866 
2867     os::SuspendResume::State result = osthread->sr.cancel_suspend();
2868     if (result == os::SuspendResume::SR_RUNNING) {
2869       // cancelled
2870       return false;
2871     } else if (result == os::SuspendResume::SR_SUSPENDED) {
2872       // somehow managed to suspend
2873       return true;
2874     } else {
2875       ShouldNotReachHere();
2876       return false;
2877     }
2878   }
2879 
2880   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2881 
2882   for (int n = 0; !osthread->sr.is_suspended(); n++) {
2883     for (int i = 0; i < RANDOMLY_LARGE_INTEGER2 && !osthread->sr.is_suspended(); i++) {
2884       os::naked_yield();
2885     }
2886 
2887     // timeout, try to cancel the request
2888     if (n >= RANDOMLY_LARGE_INTEGER) {
2889       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2890       if (cancelled == os::SuspendResume::SR_RUNNING) {
2891         return false;
2892       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2893         return true;
2894       } else {
2895         ShouldNotReachHere();
2896         return false;
2897       }
2898     }
2899   }
2900 
2901   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2902   return true;
2903 }
2904 
2905 static void do_resume(OSThread* osthread) {
2906   //assert(osthread->sr.is_suspended(), "thread should be suspended");
2907 
2908   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2909     // failed to switch to WAKEUP_REQUEST
2910     ShouldNotReachHere();
2911     return;
2912   }
2913 
2914   while (!osthread->sr.is_running()) {
2915     if (sr_notify(osthread) == 0) {
2916       for (int n = 0; n < RANDOMLY_LARGE_INTEGER && !osthread->sr.is_running(); n++) {
2917         for (int i = 0; i < 100 && !osthread->sr.is_running(); i++) {
2918           os::naked_yield();
2919         }
2920       }
2921     } else {
2922       ShouldNotReachHere();
2923     }
2924   }
2925 
2926   guarantee(osthread->sr.is_running(), "Must be running!");
2927 }
2928 
2929 ///////////////////////////////////////////////////////////////////////////////////
2930 // signal handling (except suspend/resume)
2931 
2932 // This routine may be used by user applications as a "hook" to catch signals.
2933 // The user-defined signal handler must pass unrecognized signals to this
2934 // routine, and if it returns true (non-zero), then the signal handler must
2935 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2936 // routine will never retun false (zero), but instead will execute a VM panic
2937 // routine kill the process.
2938 //
2939 // If this routine returns false, it is OK to call it again. This allows
2940 // the user-defined signal handler to perform checks either before or after
2941 // the VM performs its own checks. Naturally, the user code would be making
2942 // a serious error if it tried to handle an exception (such as a null check
2943 // or breakpoint) that the VM was generating for its own correct operation.
2944 //
2945 // This routine may recognize any of the following kinds of signals:
2946 //   SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2947 // It should be consulted by handlers for any of those signals.
2948 //
2949 // The caller of this routine must pass in the three arguments supplied
2950 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2951 // field of the structure passed to sigaction(). This routine assumes that
2952 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2953 //
2954 // Note that the VM will print warnings if it detects conflicting signal
2955 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2956 //
2957 extern "C" JNIEXPORT int
2958 JVM_handle_aix_signal(int signo, siginfo_t* siginfo, void* ucontext, int abort_if_unrecognized);
2959 
2960 // Set thread signal mask (for some reason on AIX sigthreadmask() seems
2961 // to be the thing to call; documentation is not terribly clear about whether
2962 // pthread_sigmask also works, and if it does, whether it does the same.
2963 bool set_thread_signal_mask(int how, const sigset_t* set, sigset_t* oset) {
2964   const int rc = ::pthread_sigmask(how, set, oset);
2965   // return value semantics differ slightly for error case:
2966   // pthread_sigmask returns error number, sigthreadmask -1 and sets global errno
2967   // (so, pthread_sigmask is more theadsafe for error handling)
2968   // But success is always 0.
2969   return rc == 0 ? true : false;
2970 }
2971 
2972 // Function to unblock all signals which are, according
2973 // to POSIX, typical program error signals. If they happen while being blocked,
2974 // they typically will bring down the process immediately.
2975 bool unblock_program_error_signals() {
2976   sigset_t set;
2977   ::sigemptyset(&set);
2978   ::sigaddset(&set, SIGILL);
2979   ::sigaddset(&set, SIGBUS);
2980   ::sigaddset(&set, SIGFPE);
2981   ::sigaddset(&set, SIGSEGV);
2982   return set_thread_signal_mask(SIG_UNBLOCK, &set, NULL);
2983 }
2984 
2985 // Renamed from 'signalHandler' to avoid collision with other shared libs.
2986 static void javaSignalHandler(int sig, siginfo_t* info, void* uc) {
2987   assert(info != NULL && uc != NULL, "it must be old kernel");
2988 
2989   // Never leave program error signals blocked;
2990   // on all our platforms they would bring down the process immediately when
2991   // getting raised while being blocked.
2992   unblock_program_error_signals();
2993 
2994   int orig_errno = errno;  // Preserve errno value over signal handler.
2995   JVM_handle_aix_signal(sig, info, uc, true);
2996   errno = orig_errno;
2997 }
2998 
2999 // This boolean allows users to forward their own non-matching signals
3000 // to JVM_handle_aix_signal, harmlessly.
3001 bool os::Aix::signal_handlers_are_installed = false;
3002 
3003 // For signal-chaining
3004 bool os::Aix::libjsig_is_loaded = false;
3005 typedef struct sigaction *(*get_signal_t)(int);
3006 get_signal_t os::Aix::get_signal_action = NULL;
3007 
3008 struct sigaction* os::Aix::get_chained_signal_action(int sig) {
3009   struct sigaction *actp = NULL;
3010 
3011   if (libjsig_is_loaded) {
3012     // Retrieve the old signal handler from libjsig
3013     actp = (*get_signal_action)(sig);
3014   }
3015   if (actp == NULL) {
3016     // Retrieve the preinstalled signal handler from jvm
3017     actp = os::Posix::get_preinstalled_handler(sig);
3018   }
3019 
3020   return actp;
3021 }
3022 
3023 static bool call_chained_handler(struct sigaction *actp, int sig,
3024                                  siginfo_t *siginfo, void *context) {
3025   // Call the old signal handler
3026   if (actp->sa_handler == SIG_DFL) {
3027     // It's more reasonable to let jvm treat it as an unexpected exception
3028     // instead of taking the default action.
3029     return false;
3030   } else if (actp->sa_handler != SIG_IGN) {
3031     if ((actp->sa_flags & SA_NODEFER) == 0) {
3032       // automaticlly block the signal
3033       sigaddset(&(actp->sa_mask), sig);
3034     }
3035 
3036     sa_handler_t hand = NULL;
3037     sa_sigaction_t sa = NULL;
3038     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3039     // retrieve the chained handler
3040     if (siginfo_flag_set) {
3041       sa = actp->sa_sigaction;
3042     } else {
3043       hand = actp->sa_handler;
3044     }
3045 
3046     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3047       actp->sa_handler = SIG_DFL;
3048     }
3049 
3050     // try to honor the signal mask
3051     sigset_t oset;
3052     sigemptyset(&oset);
3053     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3054 
3055     // call into the chained handler
3056     if (siginfo_flag_set) {
3057       (*sa)(sig, siginfo, context);
3058     } else {
3059       (*hand)(sig);
3060     }
3061 
3062     // restore the signal mask
3063     pthread_sigmask(SIG_SETMASK, &oset, NULL);
3064   }
3065   // Tell jvm's signal handler the signal is taken care of.
3066   return true;
3067 }
3068 
3069 bool os::Aix::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3070   bool chained = false;
3071   // signal-chaining
3072   if (UseSignalChaining) {
3073     struct sigaction *actp = get_chained_signal_action(sig);
3074     if (actp != NULL) {
3075       chained = call_chained_handler(actp, sig, siginfo, context);
3076     }
3077   }
3078   return chained;
3079 }
3080 
3081 // for diagnostic
3082 int sigflags[NSIG];
3083 
3084 int os::Aix::get_our_sigflags(int sig) {
3085   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3086   return sigflags[sig];
3087 }
3088 
3089 void os::Aix::set_our_sigflags(int sig, int flags) {
3090   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3091   if (sig > 0 && sig < NSIG) {
3092     sigflags[sig] = flags;
3093   }
3094 }
3095 
3096 void os::Aix::set_signal_handler(int sig, bool set_installed) {
3097   // Check for overwrite.
3098   struct sigaction oldAct;
3099   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3100 
3101   void* oldhand = oldAct.sa_sigaction
3102     ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3103     : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3104   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3105       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3106       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)javaSignalHandler)) {
3107     if (AllowUserSignalHandlers || !set_installed) {
3108       // Do not overwrite; user takes responsibility to forward to us.
3109       return;
3110     } else if (UseSignalChaining) {
3111       // save the old handler in jvm
3112       os::Posix::save_preinstalled_handler(sig, oldAct);
3113       // libjsig also interposes the sigaction() call below and saves the
3114       // old sigaction on it own.
3115     } else {
3116       fatal("Encountered unexpected pre-existing sigaction handler "
3117             "%#lx for signal %d.", (long)oldhand, sig);
3118     }
3119   }
3120 
3121   struct sigaction sigAct;
3122   sigfillset(&(sigAct.sa_mask));
3123   if (!set_installed) {
3124     sigAct.sa_handler = SIG_DFL;
3125     sigAct.sa_flags = SA_RESTART;
3126   } else {
3127     sigAct.sa_sigaction = javaSignalHandler;
3128     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3129   }
3130   // Save flags, which are set by ours
3131   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3132   sigflags[sig] = sigAct.sa_flags;
3133 
3134   int ret = sigaction(sig, &sigAct, &oldAct);
3135   assert(ret == 0, "check");
3136 
3137   void* oldhand2 = oldAct.sa_sigaction
3138                  ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3139                  : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3140   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3141 }
3142 
3143 // install signal handlers for signals that HotSpot needs to
3144 // handle in order to support Java-level exception handling.
3145 void os::Aix::install_signal_handlers() {
3146   if (!signal_handlers_are_installed) {
3147     signal_handlers_are_installed = true;
3148 
3149     // signal-chaining
3150     typedef void (*signal_setting_t)();
3151     signal_setting_t begin_signal_setting = NULL;
3152     signal_setting_t end_signal_setting = NULL;
3153     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3154                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3155     if (begin_signal_setting != NULL) {
3156       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3157                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3158       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3159                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3160       libjsig_is_loaded = true;
3161       assert(UseSignalChaining, "should enable signal-chaining");
3162     }
3163     if (libjsig_is_loaded) {
3164       // Tell libjsig jvm is setting signal handlers.
3165       (*begin_signal_setting)();
3166     }
3167 
3168     set_signal_handler(SIGSEGV, true);
3169     set_signal_handler(SIGPIPE, true);
3170     set_signal_handler(SIGBUS, true);
3171     set_signal_handler(SIGILL, true);
3172     set_signal_handler(SIGFPE, true);
3173     set_signal_handler(SIGTRAP, true);
3174     set_signal_handler(SIGXFSZ, true);
3175 
3176     if (libjsig_is_loaded) {
3177       // Tell libjsig jvm finishes setting signal handlers.
3178       (*end_signal_setting)();
3179     }
3180 
3181     // We don't activate signal checker if libjsig is in place, we trust ourselves
3182     // and if UserSignalHandler is installed all bets are off.
3183     // Log that signal checking is off only if -verbose:jni is specified.
3184     if (CheckJNICalls) {
3185       if (libjsig_is_loaded) {
3186         tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3187         check_signals = false;
3188       }
3189       if (AllowUserSignalHandlers) {
3190         tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3191         check_signals = false;
3192       }
3193       // Need to initialize check_signal_done.
3194       ::sigemptyset(&check_signal_done);
3195     }
3196   }
3197 }
3198 
3199 static const char* get_signal_handler_name(address handler,
3200                                            char* buf, int buflen) {
3201   int offset;
3202   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3203   if (found) {
3204     // skip directory names
3205     const char *p1, *p2;
3206     p1 = buf;
3207     size_t len = strlen(os::file_separator());
3208     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3209     // The way os::dll_address_to_library_name is implemented on Aix
3210     // right now, it always returns -1 for the offset which is not
3211     // terribly informative.
3212     // Will fix that. For now, omit the offset.
3213     jio_snprintf(buf, buflen, "%s", p1);
3214   } else {
3215     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3216   }
3217   return buf;
3218 }
3219 
3220 static void print_signal_handler(outputStream* st, int sig,
3221                                  char* buf, size_t buflen) {
3222   struct sigaction sa;
3223   sigaction(sig, NULL, &sa);
3224 
3225   st->print("%s: ", os::exception_name(sig, buf, buflen));
3226 
3227   address handler = (sa.sa_flags & SA_SIGINFO)
3228     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3229     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3230 
3231   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3232     st->print("SIG_DFL");
3233   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3234     st->print("SIG_IGN");
3235   } else {
3236     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3237   }
3238 
3239   // Print readable mask.
3240   st->print(", sa_mask[0]=");
3241   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3242 
3243   address rh = VMError::get_resetted_sighandler(sig);
3244   // May be, handler was resetted by VMError?
3245   if (rh != NULL) {
3246     handler = rh;
3247     sa.sa_flags = VMError::get_resetted_sigflags(sig);
3248   }
3249 
3250   // Print textual representation of sa_flags.
3251   st->print(", sa_flags=");
3252   os::Posix::print_sa_flags(st, sa.sa_flags);
3253 
3254   // Check: is it our handler?
3255   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)javaSignalHandler) ||
3256       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3257     // It is our signal handler.
3258     // Check for flags, reset system-used one!
3259     if ((int)sa.sa_flags != os::Aix::get_our_sigflags(sig)) {
3260       st->print(", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3261                 os::Aix::get_our_sigflags(sig));
3262     }
3263   }
3264   st->cr();
3265 }
3266 
3267 #define DO_SIGNAL_CHECK(sig) \
3268   if (!sigismember(&check_signal_done, sig)) \
3269     os::Aix::check_signal_handler(sig)
3270 
3271 // This method is a periodic task to check for misbehaving JNI applications
3272 // under CheckJNI, we can add any periodic checks here
3273 
3274 void os::run_periodic_checks() {
3275 
3276   if (check_signals == false) return;
3277 
3278   // SEGV and BUS if overridden could potentially prevent
3279   // generation of hs*.log in the event of a crash, debugging
3280   // such a case can be very challenging, so we absolutely
3281   // check the following for a good measure:
3282   DO_SIGNAL_CHECK(SIGSEGV);
3283   DO_SIGNAL_CHECK(SIGILL);
3284   DO_SIGNAL_CHECK(SIGFPE);
3285   DO_SIGNAL_CHECK(SIGBUS);
3286   DO_SIGNAL_CHECK(SIGPIPE);
3287   DO_SIGNAL_CHECK(SIGXFSZ);
3288   if (UseSIGTRAP) {
3289     DO_SIGNAL_CHECK(SIGTRAP);
3290   }
3291 
3292   // ReduceSignalUsage allows the user to override these handlers
3293   // see comments at the very top and jvm_md.h
3294   if (!ReduceSignalUsage) {
3295     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3296     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3297     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3298     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3299   }
3300 
3301   DO_SIGNAL_CHECK(SR_signum);
3302 }
3303 
3304 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3305 
3306 static os_sigaction_t os_sigaction = NULL;
3307 
3308 void os::Aix::check_signal_handler(int sig) {
3309   char buf[O_BUFLEN];
3310   address jvmHandler = NULL;
3311 
3312   struct sigaction act;
3313   if (os_sigaction == NULL) {
3314     // only trust the default sigaction, in case it has been interposed
3315     os_sigaction = CAST_TO_FN_PTR(os_sigaction_t, dlsym(RTLD_DEFAULT, "sigaction"));
3316     if (os_sigaction == NULL) return;
3317   }
3318 
3319   os_sigaction(sig, (struct sigaction*)NULL, &act);
3320 
3321   address thisHandler = (act.sa_flags & SA_SIGINFO)
3322     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3323     : CAST_FROM_FN_PTR(address, act.sa_handler);
3324 
3325   switch(sig) {
3326   case SIGSEGV:
3327   case SIGBUS:
3328   case SIGFPE:
3329   case SIGPIPE:
3330   case SIGILL:
3331   case SIGXFSZ:
3332     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)javaSignalHandler);
3333     break;
3334 
3335   case SHUTDOWN1_SIGNAL:
3336   case SHUTDOWN2_SIGNAL:
3337   case SHUTDOWN3_SIGNAL:
3338   case BREAK_SIGNAL:
3339     jvmHandler = (address)user_handler();
3340     break;
3341 
3342   default:
3343     if (sig == SR_signum) {
3344       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3345     } else {
3346       return;
3347     }
3348     break;
3349   }
3350 
3351   if (thisHandler != jvmHandler) {
3352     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3353     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3354     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3355     // No need to check this sig any longer
3356     sigaddset(&check_signal_done, sig);
3357     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3358     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3359       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3360                     exception_name(sig, buf, O_BUFLEN));
3361     }
3362   } else if (os::Aix::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Aix::get_our_sigflags(sig)) {
3363     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3364     tty->print("expected:");
3365     os::Posix::print_sa_flags(tty, os::Aix::get_our_sigflags(sig));
3366     tty->cr();
3367     tty->print("  found:");
3368     os::Posix::print_sa_flags(tty, act.sa_flags);
3369     tty->cr();
3370     // No need to check this sig any longer
3371     sigaddset(&check_signal_done, sig);
3372   }
3373 
3374   // Dump all the signal
3375   if (sigismember(&check_signal_done, sig)) {
3376     print_signal_handlers(tty, buf, O_BUFLEN);
3377   }
3378 }
3379 
3380 // To install functions for atexit system call
3381 extern "C" {
3382   static void perfMemory_exit_helper() {
3383     perfMemory_exit();
3384   }
3385 }
3386 
3387 // This is called _before_ the most of global arguments have been parsed.
3388 void os::init(void) {
3389   // This is basic, we want to know if that ever changes.
3390   // (Shared memory boundary is supposed to be a 256M aligned.)
3391   assert(SHMLBA == ((uint64_t)0x10000000ULL)/*256M*/, "unexpected");
3392 
3393   // Record process break at startup.
3394   g_brk_at_startup = (address) ::sbrk(0);
3395   assert(g_brk_at_startup != (address) -1, "sbrk failed");
3396 
3397   // First off, we need to know whether we run on AIX or PASE, and
3398   // the OS level we run on.
3399   os::Aix::initialize_os_info();
3400 
3401   // Scan environment (SPEC1170 behaviour, etc).
3402   os::Aix::scan_environment();
3403 
3404   // Probe multipage support.
3405   query_multipage_support();
3406 
3407   // Act like we only have one page size by eliminating corner cases which
3408   // we did not support very well anyway.
3409   // We have two input conditions:
3410   // 1) Data segment page size. This is controlled by linker setting (datapsize) on the
3411   //    launcher, and/or by LDR_CNTRL environment variable. The latter overrules the linker
3412   //    setting.
3413   //    Data segment page size is important for us because it defines the thread stack page
3414   //    size, which is needed for guard page handling, stack banging etc.
3415   // 2) The ability to allocate 64k pages dynamically. If this is a given, java heap can
3416   //    and should be allocated with 64k pages.
3417   //
3418   // So, we do the following:
3419   // LDR_CNTRL    can_use_64K_pages_dynamically       what we do                      remarks
3420   // 4K           no                                  4K                              old systems (aix 5.2, as/400 v5r4) or new systems with AME activated
3421   // 4k           yes                                 64k (treat 4k stacks as 64k)    different loader than java and standard settings
3422   // 64k          no              --- AIX 5.2 ? ---
3423   // 64k          yes                                 64k                             new systems and standard java loader (we set datapsize=64k when linking)
3424 
3425   // We explicitly leave no option to change page size, because only upgrading would work,
3426   // not downgrading (if stack page size is 64k you cannot pretend its 4k).
3427 
3428   if (g_multipage_support.datapsize == 4*K) {
3429     // datapsize = 4K. Data segment, thread stacks are 4K paged.
3430     if (g_multipage_support.can_use_64K_pages) {
3431       // .. but we are able to use 64K pages dynamically.
3432       // This would be typical for java launchers which are not linked
3433       // with datapsize=64K (like, any other launcher but our own).
3434       //
3435       // In this case it would be smart to allocate the java heap with 64K
3436       // to get the performance benefit, and to fake 64k pages for the
3437       // data segment (when dealing with thread stacks).
3438       //
3439       // However, leave a possibility to downgrade to 4K, using
3440       // -XX:-Use64KPages.
3441       if (Use64KPages) {
3442         trcVerbose("64K page mode (faked for data segment)");
3443         Aix::_page_size = 64*K;
3444       } else {
3445         trcVerbose("4K page mode (Use64KPages=off)");
3446         Aix::_page_size = 4*K;
3447       }
3448     } else {
3449       // .. and not able to allocate 64k pages dynamically. Here, just
3450       // fall back to 4K paged mode and use mmap for everything.
3451       trcVerbose("4K page mode");
3452       Aix::_page_size = 4*K;
3453       FLAG_SET_ERGO(Use64KPages, false);
3454     }
3455   } else {
3456     // datapsize = 64k. Data segment, thread stacks are 64k paged.
3457     // This normally means that we can allocate 64k pages dynamically.
3458     // (There is one special case where this may be false: EXTSHM=on.
3459     // but we decided to not support that mode).
3460     assert0(g_multipage_support.can_use_64K_pages);
3461     Aix::_page_size = 64*K;
3462     trcVerbose("64K page mode");
3463     FLAG_SET_ERGO(Use64KPages, true);
3464   }
3465 
3466   // For now UseLargePages is just ignored.
3467   FLAG_SET_ERGO(UseLargePages, false);
3468   _page_sizes[0] = 0;
3469 
3470   // debug trace
3471   trcVerbose("os::vm_page_size %s", describe_pagesize(os::vm_page_size()));
3472 
3473   // Next, we need to initialize libo4 and libperfstat libraries.
3474   if (os::Aix::on_pase()) {
3475     os::Aix::initialize_libo4();
3476   } else {
3477     os::Aix::initialize_libperfstat();
3478   }
3479 
3480   // Reset the perfstat information provided by ODM.
3481   if (os::Aix::on_aix()) {
3482     libperfstat::perfstat_reset();
3483   }
3484 
3485   // Now initialze basic system properties. Note that for some of the values we
3486   // need libperfstat etc.
3487   os::Aix::initialize_system_info();
3488 
3489   clock_tics_per_sec = sysconf(_SC_CLK_TCK);
3490 
3491   init_random(1234567);
3492 
3493   // _main_thread points to the thread that created/loaded the JVM.
3494   Aix::_main_thread = pthread_self();
3495 
3496   initial_time_count = javaTimeNanos();
3497 
3498   os::Posix::init();
3499 }
3500 
3501 // This is called _after_ the global arguments have been parsed.
3502 jint os::init_2(void) {
3503 
3504   // This could be set after os::Posix::init() but all platforms
3505   // have to set it the same so we have to mirror Solaris.
3506   DEBUG_ONLY(os::set_mutex_init_done();)
3507 
3508   os::Posix::init_2();
3509 
3510   if (os::Aix::on_pase()) {
3511     trcVerbose("Running on PASE.");
3512   } else {
3513     trcVerbose("Running on AIX (not PASE).");
3514   }
3515 
3516   trcVerbose("processor count: %d", os::_processor_count);
3517   trcVerbose("physical memory: %lu", Aix::_physical_memory);
3518 
3519   // Initially build up the loaded dll map.
3520   LoadedLibraries::reload();
3521   if (Verbose) {
3522     trcVerbose("Loaded Libraries: ");
3523     LoadedLibraries::print(tty);
3524   }
3525 
3526   // initialize suspend/resume support - must do this before signal_sets_init()
3527   if (SR_initialize() != 0) {
3528     perror("SR_initialize failed");
3529     return JNI_ERR;
3530   }
3531 
3532   Aix::signal_sets_init();
3533   Aix::install_signal_handlers();
3534   // Initialize data for jdk.internal.misc.Signal
3535   if (!ReduceSignalUsage) {
3536     jdk_misc_signal_init();
3537   }
3538 
3539   // Check and sets minimum stack sizes against command line options
3540   if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
3541     return JNI_ERR;
3542   }
3543 
3544   if (UseNUMA) {
3545     UseNUMA = false;
3546     warning("NUMA optimizations are not available on this OS.");
3547   }
3548 
3549   if (MaxFDLimit) {
3550     // Set the number of file descriptors to max. print out error
3551     // if getrlimit/setrlimit fails but continue regardless.
3552     struct rlimit nbr_files;
3553     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3554     if (status != 0) {
3555       log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3556     } else {
3557       nbr_files.rlim_cur = nbr_files.rlim_max;
3558       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3559       if (status != 0) {
3560         log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3561       }
3562     }
3563   }
3564 
3565   if (PerfAllowAtExitRegistration) {
3566     // Only register atexit functions if PerfAllowAtExitRegistration is set.
3567     // At exit functions can be delayed until process exit time, which
3568     // can be problematic for embedded VM situations. Embedded VMs should
3569     // call DestroyJavaVM() to assure that VM resources are released.
3570 
3571     // Note: perfMemory_exit_helper atexit function may be removed in
3572     // the future if the appropriate cleanup code can be added to the
3573     // VM_Exit VMOperation's doit method.
3574     if (atexit(perfMemory_exit_helper) != 0) {
3575       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
3576     }
3577   }
3578 
3579   // initialize thread priority policy
3580   prio_init();
3581 
3582   return JNI_OK;
3583 }
3584 
3585 int os::active_processor_count() {
3586   // User has overridden the number of active processors
3587   if (ActiveProcessorCount > 0) {
3588     log_trace(os)("active_processor_count: "
3589                   "active processor count set by user : %d",
3590                   ActiveProcessorCount);
3591     return ActiveProcessorCount;
3592   }
3593 
3594   int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
3595   assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check");
3596   return online_cpus;
3597 }
3598 
3599 void os::set_native_thread_name(const char *name) {
3600   // Not yet implemented.
3601   return;
3602 }
3603 
3604 bool os::bind_to_processor(uint processor_id) {
3605   // Not yet implemented.
3606   return false;
3607 }
3608 
3609 void os::SuspendedThreadTask::internal_do_task() {
3610   if (do_suspend(_thread->osthread())) {
3611     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3612     do_task(context);
3613     do_resume(_thread->osthread());
3614   }
3615 }
3616 
3617 ////////////////////////////////////////////////////////////////////////////////
3618 // debug support
3619 
3620 bool os::find(address addr, outputStream* st) {
3621 
3622   st->print(PTR_FORMAT ": ", addr);
3623 
3624   loaded_module_t lm;
3625   if (LoadedLibraries::find_for_text_address(addr, &lm) != NULL ||
3626       LoadedLibraries::find_for_data_address(addr, &lm) != NULL) {
3627     st->print_cr("%s", lm.path);
3628     return true;
3629   }
3630 
3631   return false;
3632 }
3633 
3634 ////////////////////////////////////////////////////////////////////////////////
3635 // misc
3636 
3637 // This does not do anything on Aix. This is basically a hook for being
3638 // able to use structured exception handling (thread-local exception filters)
3639 // on, e.g., Win32.
3640 void
3641 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
3642                          JavaCallArguments* args, Thread* thread) {
3643   f(value, method, args, thread);
3644 }
3645 
3646 void os::print_statistics() {
3647 }
3648 
3649 bool os::message_box(const char* title, const char* message) {
3650   int i;
3651   fdStream err(defaultStream::error_fd());
3652   for (i = 0; i < 78; i++) err.print_raw("=");
3653   err.cr();
3654   err.print_raw_cr(title);
3655   for (i = 0; i < 78; i++) err.print_raw("-");
3656   err.cr();
3657   err.print_raw_cr(message);
3658   for (i = 0; i < 78; i++) err.print_raw("=");
3659   err.cr();
3660 
3661   char buf[16];
3662   // Prevent process from exiting upon "read error" without consuming all CPU
3663   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3664 
3665   return buf[0] == 'y' || buf[0] == 'Y';
3666 }
3667 
3668 // Is a (classpath) directory empty?
3669 bool os::dir_is_empty(const char* path) {
3670   DIR *dir = NULL;
3671   struct dirent *ptr;
3672 
3673   dir = opendir(path);
3674   if (dir == NULL) return true;
3675 
3676   /* Scan the directory */
3677   bool result = true;
3678   while (result && (ptr = readdir(dir)) != NULL) {
3679     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3680       result = false;
3681     }
3682   }
3683   closedir(dir);
3684   return result;
3685 }
3686 
3687 // This code originates from JDK's sysOpen and open64_w
3688 // from src/solaris/hpi/src/system_md.c
3689 
3690 int os::open(const char *path, int oflag, int mode) {
3691 
3692   if (strlen(path) > MAX_PATH - 1) {
3693     errno = ENAMETOOLONG;
3694     return -1;
3695   }
3696   // AIX 7.X now supports O_CLOEXEC too, like modern Linux; but we have to be careful, see
3697   // IV90804: OPENING A FILE IN AFS WITH O_CLOEXEC FAILS WITH AN EINVAL ERROR APPLIES TO AIX 7100-04 17/04/14 PTF PECHANGE
3698   int oflag_with_o_cloexec = oflag | O_CLOEXEC;
3699 
3700   int fd = ::open64(path, oflag_with_o_cloexec, mode);
3701   if (fd == -1) {
3702     // we might fail in the open call when O_CLOEXEC is set, so try again without (see IV90804)
3703     fd = ::open64(path, oflag, mode);
3704     if (fd == -1) {
3705       return -1;
3706     }
3707   }
3708 
3709   // If the open succeeded, the file might still be a directory.
3710   {
3711     struct stat64 buf64;
3712     int ret = ::fstat64(fd, &buf64);
3713     int st_mode = buf64.st_mode;
3714 
3715     if (ret != -1) {
3716       if ((st_mode & S_IFMT) == S_IFDIR) {
3717         errno = EISDIR;
3718         ::close(fd);
3719         return -1;
3720       }
3721     } else {
3722       ::close(fd);
3723       return -1;
3724     }
3725   }
3726 
3727   // All file descriptors that are opened in the JVM and not
3728   // specifically destined for a subprocess should have the
3729   // close-on-exec flag set. If we don't set it, then careless 3rd
3730   // party native code might fork and exec without closing all
3731   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3732   // UNIXProcess.c), and this in turn might:
3733   //
3734   // - cause end-of-file to fail to be detected on some file
3735   //   descriptors, resulting in mysterious hangs, or
3736   //
3737   // - might cause an fopen in the subprocess to fail on a system
3738   //   suffering from bug 1085341.
3739 
3740   // Validate that the use of the O_CLOEXEC flag on open above worked.
3741   static sig_atomic_t O_CLOEXEC_is_known_to_work = 0;
3742   if (O_CLOEXEC_is_known_to_work == 0) {
3743     int flags = ::fcntl(fd, F_GETFD);
3744     if (flags != -1) {
3745       if ((flags & FD_CLOEXEC) != 0) {
3746         O_CLOEXEC_is_known_to_work = 1;
3747       } else { // it does not work
3748         ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3749         O_CLOEXEC_is_known_to_work = -1;
3750       }
3751     }
3752   } else if (O_CLOEXEC_is_known_to_work == -1) {
3753     int flags = ::fcntl(fd, F_GETFD);
3754     if (flags != -1) {
3755       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3756     }
3757   }
3758 
3759   return fd;
3760 }
3761 
3762 // create binary file, rewriting existing file if required
3763 int os::create_binary_file(const char* path, bool rewrite_existing) {
3764   int oflags = O_WRONLY | O_CREAT;
3765   if (!rewrite_existing) {
3766     oflags |= O_EXCL;
3767   }
3768   return ::open64(path, oflags, S_IREAD | S_IWRITE);
3769 }
3770 
3771 // return current position of file pointer
3772 jlong os::current_file_offset(int fd) {
3773   return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
3774 }
3775 
3776 // move file pointer to the specified offset
3777 jlong os::seek_to_file_offset(int fd, jlong offset) {
3778   return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
3779 }
3780 
3781 // This code originates from JDK's sysAvailable
3782 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3783 
3784 int os::available(int fd, jlong *bytes) {
3785   jlong cur, end;
3786   int mode;
3787   struct stat64 buf64;
3788 
3789   if (::fstat64(fd, &buf64) >= 0) {
3790     mode = buf64.st_mode;
3791     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3792       int n;
3793       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3794         *bytes = n;
3795         return 1;
3796       }
3797     }
3798   }
3799   if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
3800     return 0;
3801   } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
3802     return 0;
3803   } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
3804     return 0;
3805   }
3806   *bytes = end - cur;
3807   return 1;
3808 }
3809 
3810 // Map a block of memory.
3811 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3812                         char *addr, size_t bytes, bool read_only,
3813                         bool allow_exec) {
3814   int prot;
3815   int flags = MAP_PRIVATE;
3816 
3817   if (read_only) {
3818     prot = PROT_READ;
3819     flags = MAP_SHARED;
3820   } else {
3821     prot = PROT_READ | PROT_WRITE;
3822     flags = MAP_PRIVATE;
3823   }
3824 
3825   if (allow_exec) {
3826     prot |= PROT_EXEC;
3827   }
3828 
3829   if (addr != NULL) {
3830     flags |= MAP_FIXED;
3831   }
3832 
3833   // Allow anonymous mappings if 'fd' is -1.
3834   if (fd == -1) {
3835     flags |= MAP_ANONYMOUS;
3836   }
3837 
3838   char* mapped_address = (char*)::mmap(addr, (size_t)bytes, prot, flags,
3839                                      fd, file_offset);
3840   if (mapped_address == MAP_FAILED) {
3841     return NULL;
3842   }
3843   return mapped_address;
3844 }
3845 
3846 // Remap a block of memory.
3847 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3848                           char *addr, size_t bytes, bool read_only,
3849                           bool allow_exec) {
3850   // same as map_memory() on this OS
3851   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3852                         allow_exec);
3853 }
3854 
3855 // Unmap a block of memory.
3856 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3857   return munmap(addr, bytes) == 0;
3858 }
3859 
3860 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3861 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3862 // of a thread.
3863 //
3864 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3865 // the fast estimate available on the platform.
3866 
3867 jlong os::current_thread_cpu_time() {
3868   // return user + sys since the cost is the same
3869   const jlong n = os::thread_cpu_time(Thread::current(), true /* user + sys */);
3870   assert(n >= 0, "negative CPU time");
3871   return n;
3872 }
3873 
3874 jlong os::thread_cpu_time(Thread* thread) {
3875   // consistent with what current_thread_cpu_time() returns
3876   const jlong n = os::thread_cpu_time(thread, true /* user + sys */);
3877   assert(n >= 0, "negative CPU time");
3878   return n;
3879 }
3880 
3881 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3882   const jlong n = os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3883   assert(n >= 0, "negative CPU time");
3884   return n;
3885 }
3886 
3887 static bool thread_cpu_time_unchecked(Thread* thread, jlong* p_sys_time, jlong* p_user_time) {
3888   bool error = false;
3889 
3890   jlong sys_time = 0;
3891   jlong user_time = 0;
3892 
3893   // Reimplemented using getthrds64().
3894   //
3895   // Works like this:
3896   // For the thread in question, get the kernel thread id. Then get the
3897   // kernel thread statistics using that id.
3898   //
3899   // This only works of course when no pthread scheduling is used,
3900   // i.e. there is a 1:1 relationship to kernel threads.
3901   // On AIX, see AIXTHREAD_SCOPE variable.
3902 
3903   pthread_t pthtid = thread->osthread()->pthread_id();
3904 
3905   // retrieve kernel thread id for the pthread:
3906   tid64_t tid = 0;
3907   struct __pthrdsinfo pinfo;
3908   // I just love those otherworldly IBM APIs which force me to hand down
3909   // dummy buffers for stuff I dont care for...
3910   char dummy[1];
3911   int dummy_size = sizeof(dummy);
3912   if (pthread_getthrds_np(&pthtid, PTHRDSINFO_QUERY_TID, &pinfo, sizeof(pinfo),
3913                           dummy, &dummy_size) == 0) {
3914     tid = pinfo.__pi_tid;
3915   } else {
3916     tty->print_cr("pthread_getthrds_np failed.");
3917     error = true;
3918   }
3919 
3920   // retrieve kernel timing info for that kernel thread
3921   if (!error) {
3922     struct thrdentry64 thrdentry;
3923     if (getthrds64(getpid(), &thrdentry, sizeof(thrdentry), &tid, 1) == 1) {
3924       sys_time = thrdentry.ti_ru.ru_stime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_stime.tv_usec * 1000LL;
3925       user_time = thrdentry.ti_ru.ru_utime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_utime.tv_usec * 1000LL;
3926     } else {
3927       tty->print_cr("pthread_getthrds_np failed.");
3928       error = true;
3929     }
3930   }
3931 
3932   if (p_sys_time) {
3933     *p_sys_time = sys_time;
3934   }
3935 
3936   if (p_user_time) {
3937     *p_user_time = user_time;
3938   }
3939 
3940   if (error) {
3941     return false;
3942   }
3943 
3944   return true;
3945 }
3946 
3947 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3948   jlong sys_time;
3949   jlong user_time;
3950 
3951   if (!thread_cpu_time_unchecked(thread, &sys_time, &user_time)) {
3952     return -1;
3953   }
3954 
3955   return user_sys_cpu_time ? sys_time + user_time : user_time;
3956 }
3957 
3958 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3959   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3960   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3961   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3962   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3963 }
3964 
3965 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3966   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3967   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3968   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3969   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3970 }
3971 
3972 bool os::is_thread_cpu_time_supported() {
3973   return true;
3974 }
3975 
3976 // System loadavg support. Returns -1 if load average cannot be obtained.
3977 // For now just return the system wide load average (no processor sets).
3978 int os::loadavg(double values[], int nelem) {
3979 
3980   guarantee(nelem >= 0 && nelem <= 3, "argument error");
3981   guarantee(values, "argument error");
3982 
3983   if (os::Aix::on_pase()) {
3984 
3985     // AS/400 PASE: use libo4 porting library
3986     double v[3] = { 0.0, 0.0, 0.0 };
3987 
3988     if (libo4::get_load_avg(v, v + 1, v + 2)) {
3989       for (int i = 0; i < nelem; i ++) {
3990         values[i] = v[i];
3991       }
3992       return nelem;
3993     } else {
3994       return -1;
3995     }
3996 
3997   } else {
3998 
3999     // AIX: use libperfstat
4000     libperfstat::cpuinfo_t ci;
4001     if (libperfstat::get_cpuinfo(&ci)) {
4002       for (int i = 0; i < nelem; i++) {
4003         values[i] = ci.loadavg[i];
4004       }
4005     } else {
4006       return -1;
4007     }
4008     return nelem;
4009   }
4010 }
4011 
4012 void os::pause() {
4013   char filename[MAX_PATH];
4014   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4015     jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
4016   } else {
4017     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4018   }
4019 
4020   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4021   if (fd != -1) {
4022     struct stat buf;
4023     ::close(fd);
4024     while (::stat(filename, &buf) == 0) {
4025       (void)::poll(NULL, 0, 100);
4026     }
4027   } else {
4028     trcVerbose("Could not open pause file '%s', continuing immediately.", filename);
4029   }
4030 }
4031 
4032 bool os::is_primordial_thread(void) {
4033   if (pthread_self() == (pthread_t)1) {
4034     return true;
4035   } else {
4036     return false;
4037   }
4038 }
4039 
4040 // OS recognitions (PASE/AIX, OS level) call this before calling any
4041 // one of Aix::on_pase(), Aix::os_version() static
4042 void os::Aix::initialize_os_info() {
4043 
4044   assert(_on_pase == -1 && _os_version == 0, "already called.");
4045 
4046   struct utsname uts;
4047   memset(&uts, 0, sizeof(uts));
4048   strcpy(uts.sysname, "?");
4049   if (::uname(&uts) == -1) {
4050     trcVerbose("uname failed (%d)", errno);
4051     guarantee(0, "Could not determine whether we run on AIX or PASE");
4052   } else {
4053     trcVerbose("uname says: sysname \"%s\" version \"%s\" release \"%s\" "
4054                "node \"%s\" machine \"%s\"\n",
4055                uts.sysname, uts.version, uts.release, uts.nodename, uts.machine);
4056     const int major = atoi(uts.version);
4057     assert(major > 0, "invalid OS version");
4058     const int minor = atoi(uts.release);
4059     assert(minor > 0, "invalid OS release");
4060     _os_version = (major << 24) | (minor << 16);
4061     char ver_str[20] = {0};
4062     const char* name_str = "unknown OS";
4063     if (strcmp(uts.sysname, "OS400") == 0) {
4064       // We run on AS/400 PASE. We do not support versions older than V5R4M0.
4065       _on_pase = 1;
4066       if (os_version_short() < 0x0504) {
4067         trcVerbose("OS/400 releases older than V5R4M0 not supported.");
4068         assert(false, "OS/400 release too old.");
4069       }
4070       name_str = "OS/400 (pase)";
4071       jio_snprintf(ver_str, sizeof(ver_str), "%u.%u", major, minor);
4072     } else if (strcmp(uts.sysname, "AIX") == 0) {
4073       // We run on AIX. We do not support versions older than AIX 7.1.
4074       _on_pase = 0;
4075       // Determine detailed AIX version: Version, Release, Modification, Fix Level.
4076       odmWrapper::determine_os_kernel_version(&_os_version);
4077       if (os_version_short() < 0x0701) {
4078         trcVerbose("AIX releases older than AIX 7.1 are not supported.");
4079         assert(false, "AIX release too old.");
4080       }
4081       name_str = "AIX";
4082       jio_snprintf(ver_str, sizeof(ver_str), "%u.%u.%u.%u",
4083                    major, minor, (_os_version >> 8) & 0xFF, _os_version & 0xFF);
4084     } else {
4085       assert(false, "%s", name_str);
4086     }
4087     trcVerbose("We run on %s %s", name_str, ver_str);
4088   }
4089 
4090   guarantee(_on_pase != -1 && _os_version, "Could not determine AIX/OS400 release");
4091 } // end: os::Aix::initialize_os_info()
4092 
4093 // Scan environment for important settings which might effect the VM.
4094 // Trace out settings. Warn about invalid settings and/or correct them.
4095 //
4096 // Must run after os::Aix::initialue_os_info().
4097 void os::Aix::scan_environment() {
4098 
4099   char* p;
4100   int rc;
4101 
4102   // Warn explicity if EXTSHM=ON is used. That switch changes how
4103   // System V shared memory behaves. One effect is that page size of
4104   // shared memory cannot be change dynamically, effectivly preventing
4105   // large pages from working.
4106   // This switch was needed on AIX 32bit, but on AIX 64bit the general
4107   // recommendation is (in OSS notes) to switch it off.
4108   p = ::getenv("EXTSHM");
4109   trcVerbose("EXTSHM=%s.", p ? p : "<unset>");
4110   if (p && strcasecmp(p, "ON") == 0) {
4111     _extshm = 1;
4112     trcVerbose("*** Unsupported mode! Please remove EXTSHM from your environment! ***");
4113     if (!AllowExtshm) {
4114       // We allow under certain conditions the user to continue. However, we want this
4115       // to be a fatal error by default. On certain AIX systems, leaving EXTSHM=ON means
4116       // that the VM is not able to allocate 64k pages for the heap.
4117       // We do not want to run with reduced performance.
4118       vm_exit_during_initialization("EXTSHM is ON. Please remove EXTSHM from your environment.");
4119     }
4120   } else {
4121     _extshm = 0;
4122   }
4123 
4124   // SPEC1170 behaviour: will change the behaviour of a number of POSIX APIs.
4125   // Not tested, not supported.
4126   //
4127   // Note that it might be worth the trouble to test and to require it, if only to
4128   // get useful return codes for mprotect.
4129   //
4130   // Note: Setting XPG_SUS_ENV in the process is too late. Must be set earlier (before
4131   // exec() ? before loading the libjvm ? ....)
4132   p = ::getenv("XPG_SUS_ENV");
4133   trcVerbose("XPG_SUS_ENV=%s.", p ? p : "<unset>");
4134   if (p && strcmp(p, "ON") == 0) {
4135     _xpg_sus_mode = 1;
4136     trcVerbose("Unsupported setting: XPG_SUS_ENV=ON");
4137     // This is not supported. Worst of all, it changes behaviour of mmap MAP_FIXED to
4138     // clobber address ranges. If we ever want to support that, we have to do some
4139     // testing first.
4140     guarantee(false, "XPG_SUS_ENV=ON not supported");
4141   } else {
4142     _xpg_sus_mode = 0;
4143   }
4144 
4145   if (os::Aix::on_pase()) {
4146     p = ::getenv("QIBM_MULTI_THREADED");
4147     trcVerbose("QIBM_MULTI_THREADED=%s.", p ? p : "<unset>");
4148   }
4149 
4150   p = ::getenv("LDR_CNTRL");
4151   trcVerbose("LDR_CNTRL=%s.", p ? p : "<unset>");
4152   if (os::Aix::on_pase() && os::Aix::os_version_short() == 0x0701) {
4153     if (p && ::strstr(p, "TEXTPSIZE")) {
4154       trcVerbose("*** WARNING - LDR_CNTRL contains TEXTPSIZE. "
4155         "you may experience hangs or crashes on OS/400 V7R1.");
4156     }
4157   }
4158 
4159   p = ::getenv("AIXTHREAD_GUARDPAGES");
4160   trcVerbose("AIXTHREAD_GUARDPAGES=%s.", p ? p : "<unset>");
4161 
4162 } // end: os::Aix::scan_environment()
4163 
4164 // PASE: initialize the libo4 library (PASE porting library).
4165 void os::Aix::initialize_libo4() {
4166   guarantee(os::Aix::on_pase(), "OS/400 only.");
4167   if (!libo4::init()) {
4168     trcVerbose("libo4 initialization failed.");
4169     assert(false, "libo4 initialization failed");
4170   } else {
4171     trcVerbose("libo4 initialized.");
4172   }
4173 }
4174 
4175 // AIX: initialize the libperfstat library.
4176 void os::Aix::initialize_libperfstat() {
4177   assert(os::Aix::on_aix(), "AIX only");
4178   if (!libperfstat::init()) {
4179     trcVerbose("libperfstat initialization failed.");
4180     assert(false, "libperfstat initialization failed");
4181   } else {
4182     trcVerbose("libperfstat initialized.");
4183   }
4184 }
4185 
4186 /////////////////////////////////////////////////////////////////////////////
4187 // thread stack
4188 
4189 // Get the current stack base from the OS (actually, the pthread library).
4190 // Note: usually not page aligned.
4191 address os::current_stack_base() {
4192   AixMisc::stackbounds_t bounds;
4193   bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
4194   guarantee(rc, "Unable to retrieve stack bounds.");
4195   return bounds.base;
4196 }
4197 
4198 // Get the current stack size from the OS (actually, the pthread library).
4199 // Returned size is such that (base - size) is always aligned to page size.
4200 size_t os::current_stack_size() {
4201   AixMisc::stackbounds_t bounds;
4202   bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
4203   guarantee(rc, "Unable to retrieve stack bounds.");
4204   // Align the returned stack size such that the stack low address
4205   // is aligned to page size (Note: base is usually not and we do not care).
4206   // We need to do this because caller code will assume stack low address is
4207   // page aligned and will place guard pages without checking.
4208   address low = bounds.base - bounds.size;
4209   address low_aligned = (address)align_up(low, os::vm_page_size());
4210   size_t s = bounds.base - low_aligned;
4211   return s;
4212 }
4213 
4214 extern char** environ;
4215 
4216 // Run the specified command in a separate process. Return its exit value,
4217 // or -1 on failure (e.g. can't fork a new process).
4218 // Unlike system(), this function can be called from signal handler. It
4219 // doesn't block SIGINT et al.
4220 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
4221   char* argv[4] = { (char*)"sh", (char*)"-c", cmd, NULL};
4222 
4223   pid_t pid = fork();
4224 
4225   if (pid < 0) {
4226     // fork failed
4227     return -1;
4228 
4229   } else if (pid == 0) {
4230     // child process
4231 
4232     // Try to be consistent with system(), which uses "/usr/bin/sh" on AIX.
4233     execve("/usr/bin/sh", argv, environ);
4234 
4235     // execve failed
4236     _exit(-1);
4237 
4238   } else {
4239     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4240     // care about the actual exit code, for now.
4241 
4242     int status;
4243 
4244     // Wait for the child process to exit. This returns immediately if
4245     // the child has already exited. */
4246     while (waitpid(pid, &status, 0) < 0) {
4247       switch (errno) {
4248         case ECHILD: return 0;
4249         case EINTR: break;
4250         default: return -1;
4251       }
4252     }
4253 
4254     if (WIFEXITED(status)) {
4255       // The child exited normally; get its exit code.
4256       return WEXITSTATUS(status);
4257     } else if (WIFSIGNALED(status)) {
4258       // The child exited because of a signal.
4259       // The best value to return is 0x80 + signal number,
4260       // because that is what all Unix shells do, and because
4261       // it allows callers to distinguish between process exit and
4262       // process death by signal.
4263       return 0x80 + WTERMSIG(status);
4264     } else {
4265       // Unknown exit code; pass it through.
4266       return status;
4267     }
4268   }
4269   return -1;
4270 }
4271 
4272 // Get the default path to the core file
4273 // Returns the length of the string
4274 int os::get_core_path(char* buffer, size_t bufferSize) {
4275   const char* p = get_current_directory(buffer, bufferSize);
4276 
4277   if (p == NULL) {
4278     assert(p != NULL, "failed to get current directory");
4279     return 0;
4280   }
4281 
4282   jio_snprintf(buffer, bufferSize, "%s/core or core.%d",
4283                                                p, current_process_id());
4284 
4285   return strlen(buffer);
4286 }
4287 
4288 #ifndef PRODUCT
4289 void TestReserveMemorySpecial_test() {
4290   // No tests available for this platform
4291 }
4292 #endif
4293 
4294 bool os::start_debugging(char *buf, int buflen) {
4295   int len = (int)strlen(buf);
4296   char *p = &buf[len];
4297 
4298   jio_snprintf(p, buflen -len,
4299                  "\n\n"
4300                  "Do you want to debug the problem?\n\n"
4301                  "To debug, run 'dbx -a %d'; then switch to thread tid " INTX_FORMAT ", k-tid " INTX_FORMAT "\n"
4302                  "Enter 'yes' to launch dbx automatically (PATH must include dbx)\n"
4303                  "Otherwise, press RETURN to abort...",
4304                  os::current_process_id(),
4305                  os::current_thread_id(), thread_self());
4306 
4307   bool yes = os::message_box("Unexpected Error", buf);
4308 
4309   if (yes) {
4310     // yes, user asked VM to launch debugger
4311     jio_snprintf(buf, buflen, "dbx -a %d", os::current_process_id());
4312 
4313     os::fork_and_exec(buf);
4314     yes = false;
4315   }
4316   return yes;
4317 }
4318 
4319 static inline time_t get_mtime(const char* filename) {
4320   struct stat st;
4321   int ret = os::stat(filename, &st);
4322   assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
4323   return st.st_mtime;
4324 }
4325 
4326 int os::compare_file_modified_times(const char* file1, const char* file2) {
4327   time_t t1 = get_mtime(file1);
4328   time_t t2 = get_mtime(file2);
4329   return t1 - t2;
4330 }
4331 
4332 bool os::supports_map_sync() {
4333   return false;
4334 }