1 /*
   2  * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2012, 2019 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/orderAccess.hpp"
  64 #include "runtime/os.hpp"
  65 #include "runtime/osThread.hpp"
  66 #include "runtime/perfMemory.hpp"
  67 #include "runtime/sharedRuntime.hpp"
  68 #include "runtime/statSampler.hpp"
  69 #include "runtime/stubRoutines.hpp"
  70 #include "runtime/thread.inline.hpp"
  71 #include "runtime/threadCritical.hpp"
  72 #include "runtime/timer.hpp"
  73 #include "runtime/vm_version.hpp"
  74 #include "services/attachListener.hpp"
  75 #include "services/runtimeService.hpp"
  76 #include "utilities/align.hpp"
  77 #include "utilities/decoder.hpp"
  78 #include "utilities/defaultStream.hpp"
  79 #include "utilities/events.hpp"
  80 #include "utilities/growableArray.hpp"
  81 #include "utilities/vmError.hpp"
  82 
  83 // put OS-includes here (sorted alphabetically)
  84 #include <errno.h>
  85 #include <fcntl.h>
  86 #include <inttypes.h>
  87 #include <poll.h>
  88 #include <procinfo.h>
  89 #include <pthread.h>
  90 #include <pwd.h>
  91 #include <semaphore.h>
  92 #include <signal.h>
  93 #include <stdint.h>
  94 #include <stdio.h>
  95 #include <string.h>
  96 #include <unistd.h>
  97 #include <sys/ioctl.h>
  98 #include <sys/ipc.h>
  99 #include <sys/mman.h>
 100 #include <sys/resource.h>
 101 #include <sys/select.h>
 102 #include <sys/shm.h>
 103 #include <sys/socket.h>
 104 #include <sys/stat.h>
 105 #include <sys/sysinfo.h>
 106 #include <sys/systemcfg.h>
 107 #include <sys/time.h>
 108 #include <sys/times.h>
 109 #include <sys/types.h>
 110 #include <sys/utsname.h>
 111 #include <sys/vminfo.h>
 112 #include <sys/wait.h>
 113 
 114 // Missing prototypes for various system APIs.
 115 extern "C"
 116 int mread_real_time(timebasestruct_t *t, size_t size_of_timebasestruct_t);
 117 
 118 #if !defined(_AIXVERSION_610)
 119 extern "C" int getthrds64(pid_t, struct thrdentry64*, int, tid64_t*, int);
 120 extern "C" int getprocs64(procentry64*, int, fdsinfo*, int, pid_t*, int);
 121 extern "C" int getargs(procsinfo*, int, char*, int);
 122 #endif
 123 
 124 #define MAX_PATH (2 * K)
 125 
 126 // for timer info max values which include all bits
 127 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 128 // for multipage initialization error analysis (in 'g_multipage_error')
 129 #define ERROR_MP_OS_TOO_OLD                          100
 130 #define ERROR_MP_EXTSHM_ACTIVE                       101
 131 #define ERROR_MP_VMGETINFO_FAILED                    102
 132 #define ERROR_MP_VMGETINFO_CLAIMS_NO_SUPPORT_FOR_64K 103
 133 
 134 // excerpts from systemcfg.h that might be missing on older os levels
 135 #ifndef PV_7
 136   #define PV_7 0x200000          /* Power PC 7 */
 137 #endif
 138 #ifndef PV_7_Compat
 139   #define PV_7_Compat 0x208000   /* Power PC 7 */
 140 #endif
 141 #ifndef PV_8
 142   #define PV_8 0x300000          /* Power PC 8 */
 143 #endif
 144 #ifndef PV_8_Compat
 145   #define PV_8_Compat 0x308000   /* Power PC 8 */
 146 #endif
 147 #ifndef PV_9
 148   #define PV_9 0x400000          /* Power PC 9 */
 149 #endif
 150 #ifndef PV_9_Compat
 151   #define PV_9_Compat  0x408000  /* Power PC 9 */
 152 #endif
 153 
 154 
 155 static address resolve_function_descriptor_to_code_pointer(address p);
 156 
 157 static void vmembk_print_on(outputStream* os);
 158 
 159 ////////////////////////////////////////////////////////////////////////////////
 160 // global variables (for a description see os_aix.hpp)
 161 
 162 julong    os::Aix::_physical_memory = 0;
 163 
 164 pthread_t os::Aix::_main_thread = ((pthread_t)0);
 165 int       os::Aix::_page_size = -1;
 166 
 167 // -1 = uninitialized, 0 if AIX, 1 if OS/400 pase
 168 int       os::Aix::_on_pase = -1;
 169 
 170 // 0 = uninitialized, otherwise 32 bit number:
 171 //  0xVVRRTTSS
 172 //  VV - major version
 173 //  RR - minor version
 174 //  TT - tech level, if known, 0 otherwise
 175 //  SS - service pack, if known, 0 otherwise
 176 uint32_t  os::Aix::_os_version = 0;
 177 
 178 // -1 = uninitialized, 0 - no, 1 - yes
 179 int       os::Aix::_xpg_sus_mode = -1;
 180 
 181 // -1 = uninitialized, 0 - no, 1 - yes
 182 int       os::Aix::_extshm = -1;
 183 
 184 ////////////////////////////////////////////////////////////////////////////////
 185 // local variables
 186 
 187 static volatile jlong max_real_time = 0;
 188 static jlong    initial_time_count = 0;
 189 static int      clock_tics_per_sec = 100;
 190 static sigset_t check_signal_done;         // For diagnostics to print a message once (see run_periodic_checks)
 191 static bool     check_signals      = true;
 192 static int      SR_signum          = SIGUSR2; // Signal used to suspend/resume a thread (must be > SIGSEGV, see 4355769)
 193 static sigset_t SR_sigset;
 194 
 195 // Process break recorded at startup.
 196 static address g_brk_at_startup = NULL;
 197 
 198 // This describes the state of multipage support of the underlying
 199 // OS. Note that this is of no interest to the outsize world and
 200 // therefore should not be defined in AIX class.
 201 //
 202 // AIX supports four different page sizes - 4K, 64K, 16MB, 16GB. The
 203 // latter two (16M "large" resp. 16G "huge" pages) require special
 204 // setup and are normally not available.
 205 //
 206 // AIX supports multiple page sizes per process, for:
 207 //  - Stack (of the primordial thread, so not relevant for us)
 208 //  - Data - data, bss, heap, for us also pthread stacks
 209 //  - Text - text code
 210 //  - shared memory
 211 //
 212 // Default page sizes can be set via linker options (-bdatapsize, -bstacksize, ...)
 213 // and via environment variable LDR_CNTRL (DATAPSIZE, STACKPSIZE, ...).
 214 //
 215 // For shared memory, page size can be set dynamically via
 216 // shmctl(). Different shared memory regions can have different page
 217 // sizes.
 218 //
 219 // More information can be found at AIBM info center:
 220 //   http://publib.boulder.ibm.com/infocenter/aix/v6r1/index.jsp?topic=/com.ibm.aix.prftungd/doc/prftungd/multiple_page_size_app_support.htm
 221 //
 222 static struct {
 223   size_t pagesize;            // sysconf _SC_PAGESIZE (4K)
 224   size_t datapsize;           // default data page size (LDR_CNTRL DATAPSIZE)
 225   size_t shmpsize;            // default shared memory page size (LDR_CNTRL SHMPSIZE)
 226   size_t pthr_stack_pagesize; // stack page size of pthread threads
 227   size_t textpsize;           // default text page size (LDR_CNTRL STACKPSIZE)
 228   bool can_use_64K_pages;     // True if we can alloc 64K pages dynamically with Sys V shm.
 229   bool can_use_16M_pages;     // True if we can alloc 16M pages dynamically with Sys V shm.
 230   int error;                  // Error describing if something went wrong at multipage init.
 231 } g_multipage_support = {
 232   (size_t) -1,
 233   (size_t) -1,
 234   (size_t) -1,
 235   (size_t) -1,
 236   (size_t) -1,
 237   false, false,
 238   0
 239 };
 240 
 241 // We must not accidentally allocate memory close to the BRK - even if
 242 // that would work - because then we prevent the BRK segment from
 243 // growing which may result in a malloc OOM even though there is
 244 // enough memory. The problem only arises if we shmat() or mmap() at
 245 // a specific wish address, e.g. to place the heap in a
 246 // compressed-oops-friendly way.
 247 static bool is_close_to_brk(address a) {
 248   assert0(g_brk_at_startup != NULL);
 249   if (a >= g_brk_at_startup &&
 250       a < (g_brk_at_startup + MaxExpectedDataSegmentSize)) {
 251     return true;
 252   }
 253   return false;
 254 }
 255 
 256 julong os::available_memory() {
 257   return Aix::available_memory();
 258 }
 259 
 260 julong os::Aix::available_memory() {
 261   // Avoid expensive API call here, as returned value will always be null.
 262   if (os::Aix::on_pase()) {
 263     return 0x0LL;
 264   }
 265   os::Aix::meminfo_t mi;
 266   if (os::Aix::get_meminfo(&mi)) {
 267     return mi.real_free;
 268   } else {
 269     return ULONG_MAX;
 270   }
 271 }
 272 
 273 julong os::physical_memory() {
 274   return Aix::physical_memory();
 275 }
 276 
 277 // Return true if user is running as root.
 278 
 279 bool os::have_special_privileges() {
 280   static bool init = false;
 281   static bool privileges = false;
 282   if (!init) {
 283     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 284     init = true;
 285   }
 286   return privileges;
 287 }
 288 
 289 // Helper function, emulates disclaim64 using multiple 32bit disclaims
 290 // because we cannot use disclaim64() on AS/400 and old AIX releases.
 291 static bool my_disclaim64(char* addr, size_t size) {
 292 
 293   if (size == 0) {
 294     return true;
 295   }
 296 
 297   // Maximum size 32bit disclaim() accepts. (Theoretically 4GB, but I just do not trust that.)
 298   const unsigned int maxDisclaimSize = 0x40000000;
 299 
 300   const unsigned int numFullDisclaimsNeeded = (size / maxDisclaimSize);
 301   const unsigned int lastDisclaimSize = (size % maxDisclaimSize);
 302 
 303   char* p = addr;
 304 
 305   for (int i = 0; i < numFullDisclaimsNeeded; i ++) {
 306     if (::disclaim(p, maxDisclaimSize, DISCLAIM_ZEROMEM) != 0) {
 307       trcVerbose("Cannot disclaim %p - %p (errno %d)\n", p, p + maxDisclaimSize, errno);
 308       return false;
 309     }
 310     p += maxDisclaimSize;
 311   }
 312 
 313   if (lastDisclaimSize > 0) {
 314     if (::disclaim(p, lastDisclaimSize, DISCLAIM_ZEROMEM) != 0) {
 315       trcVerbose("Cannot disclaim %p - %p (errno %d)\n", p, p + lastDisclaimSize, errno);
 316       return false;
 317     }
 318   }
 319 
 320   return true;
 321 }
 322 
 323 // Cpu architecture string
 324 #if defined(PPC32)
 325 static char cpu_arch[] = "ppc";
 326 #elif defined(PPC64)
 327 static char cpu_arch[] = "ppc64";
 328 #else
 329 #error Add appropriate cpu_arch setting
 330 #endif
 331 
 332 // Wrap the function "vmgetinfo" which is not available on older OS releases.
 333 static int checked_vmgetinfo(void *out, int command, int arg) {
 334   if (os::Aix::on_pase() && os::Aix::os_version_short() < 0x0601) {
 335     guarantee(false, "cannot call vmgetinfo on AS/400 older than V6R1");
 336   }
 337   return ::vmgetinfo(out, command, arg);
 338 }
 339 
 340 // Given an address, returns the size of the page backing that address.
 341 size_t os::Aix::query_pagesize(void* addr) {
 342 
 343   if (os::Aix::on_pase() && os::Aix::os_version_short() < 0x0601) {
 344     // AS/400 older than V6R1: no vmgetinfo here, default to 4K
 345     return 4*K;
 346   }
 347 
 348   vm_page_info pi;
 349   pi.addr = (uint64_t)addr;
 350   if (checked_vmgetinfo(&pi, VM_PAGE_INFO, sizeof(pi)) == 0) {
 351     return pi.pagesize;
 352   } else {
 353     assert(false, "vmgetinfo failed to retrieve page size");
 354     return 4*K;
 355   }
 356 }
 357 
 358 void os::Aix::initialize_system_info() {
 359 
 360   // Get the number of online(logical) cpus instead of configured.
 361   os::_processor_count = sysconf(_SC_NPROCESSORS_ONLN);
 362   assert(_processor_count > 0, "_processor_count must be > 0");
 363 
 364   // Retrieve total physical storage.
 365   os::Aix::meminfo_t mi;
 366   if (!os::Aix::get_meminfo(&mi)) {
 367     assert(false, "os::Aix::get_meminfo failed.");
 368   }
 369   _physical_memory = (julong) mi.real_total;
 370 }
 371 
 372 // Helper function for tracing page sizes.
 373 static const char* describe_pagesize(size_t pagesize) {
 374   switch (pagesize) {
 375     case 4*K : return "4K";
 376     case 64*K: return "64K";
 377     case 16*M: return "16M";
 378     case 16*G: return "16G";
 379     default:
 380       assert(false, "surprise");
 381       return "??";
 382   }
 383 }
 384 
 385 // Probe OS for multipage support.
 386 // Will fill the global g_multipage_support structure.
 387 // Must be called before calling os::large_page_init().
 388 static void query_multipage_support() {
 389 
 390   guarantee(g_multipage_support.pagesize == -1,
 391             "do not call twice");
 392 
 393   g_multipage_support.pagesize = ::sysconf(_SC_PAGESIZE);
 394 
 395   // This really would surprise me.
 396   assert(g_multipage_support.pagesize == 4*K, "surprise!");
 397 
 398   // Query default data page size (default page size for C-Heap, pthread stacks and .bss).
 399   // Default data page size is defined either by linker options (-bdatapsize)
 400   // or by environment variable LDR_CNTRL (suboption DATAPSIZE). If none is given,
 401   // default should be 4K.
 402   {
 403     void* p = ::malloc(16*M);
 404     g_multipage_support.datapsize = os::Aix::query_pagesize(p);
 405     ::free(p);
 406   }
 407 
 408   // Query default shm page size (LDR_CNTRL SHMPSIZE).
 409   // Note that this is pure curiosity. We do not rely on default page size but set
 410   // our own page size after allocated.
 411   {
 412     const int shmid = ::shmget(IPC_PRIVATE, 1, IPC_CREAT | S_IRUSR | S_IWUSR);
 413     guarantee(shmid != -1, "shmget failed");
 414     void* p = ::shmat(shmid, NULL, 0);
 415     ::shmctl(shmid, IPC_RMID, NULL);
 416     guarantee(p != (void*) -1, "shmat failed");
 417     g_multipage_support.shmpsize = os::Aix::query_pagesize(p);
 418     ::shmdt(p);
 419   }
 420 
 421   // Before querying the stack page size, make sure we are not running as primordial
 422   // thread (because primordial thread's stack may have different page size than
 423   // pthread thread stacks). Running a VM on the primordial thread won't work for a
 424   // number of reasons so we may just as well guarantee it here.
 425   guarantee0(!os::is_primordial_thread());
 426 
 427   // Query pthread stack page size. Should be the same as data page size because
 428   // pthread stacks are allocated from C-Heap.
 429   {
 430     int dummy = 0;
 431     g_multipage_support.pthr_stack_pagesize = os::Aix::query_pagesize(&dummy);
 432   }
 433 
 434   // Query default text page size (LDR_CNTRL TEXTPSIZE).
 435   {
 436     address any_function =
 437       resolve_function_descriptor_to_code_pointer((address)describe_pagesize);
 438     g_multipage_support.textpsize = os::Aix::query_pagesize(any_function);
 439   }
 440 
 441   // Now probe for support of 64K pages and 16M pages.
 442 
 443   // Before OS/400 V6R1, there is no support for pages other than 4K.
 444   if (os::Aix::on_pase_V5R4_or_older()) {
 445     trcVerbose("OS/400 < V6R1 - no large page support.");
 446     g_multipage_support.error = ERROR_MP_OS_TOO_OLD;
 447     goto query_multipage_support_end;
 448   }
 449 
 450   // Now check which page sizes the OS claims it supports, and of those, which actually can be used.
 451   {
 452     const int MAX_PAGE_SIZES = 4;
 453     psize_t sizes[MAX_PAGE_SIZES];
 454     const int num_psizes = checked_vmgetinfo(sizes, VMINFO_GETPSIZES, MAX_PAGE_SIZES);
 455     if (num_psizes == -1) {
 456       trcVerbose("vmgetinfo(VMINFO_GETPSIZES) failed (errno: %d)", errno);
 457       trcVerbose("disabling multipage support.");
 458       g_multipage_support.error = ERROR_MP_VMGETINFO_FAILED;
 459       goto query_multipage_support_end;
 460     }
 461     guarantee(num_psizes > 0, "vmgetinfo(.., VMINFO_GETPSIZES, ...) failed.");
 462     assert(num_psizes <= MAX_PAGE_SIZES, "Surprise! more than 4 page sizes?");
 463     trcVerbose("vmgetinfo(.., VMINFO_GETPSIZES, ...) returns %d supported page sizes: ", num_psizes);
 464     for (int i = 0; i < num_psizes; i ++) {
 465       trcVerbose(" %s ", describe_pagesize(sizes[i]));
 466     }
 467 
 468     // Can we use 64K, 16M pages?
 469     for (int i = 0; i < num_psizes; i ++) {
 470       const size_t pagesize = sizes[i];
 471       if (pagesize != 64*K && pagesize != 16*M) {
 472         continue;
 473       }
 474       bool can_use = false;
 475       trcVerbose("Probing support for %s pages...", describe_pagesize(pagesize));
 476       const int shmid = ::shmget(IPC_PRIVATE, pagesize,
 477         IPC_CREAT | S_IRUSR | S_IWUSR);
 478       guarantee0(shmid != -1); // Should always work.
 479       // Try to set pagesize.
 480       struct shmid_ds shm_buf = { 0 };
 481       shm_buf.shm_pagesize = pagesize;
 482       if (::shmctl(shmid, SHM_PAGESIZE, &shm_buf) != 0) {
 483         const int en = errno;
 484         ::shmctl(shmid, IPC_RMID, NULL); // As early as possible!
 485         trcVerbose("shmctl(SHM_PAGESIZE) failed with errno=%d", errno);
 486       } else {
 487         // Attach and double check pageisze.
 488         void* p = ::shmat(shmid, NULL, 0);
 489         ::shmctl(shmid, IPC_RMID, NULL); // As early as possible!
 490         guarantee0(p != (void*) -1); // Should always work.
 491         const size_t real_pagesize = os::Aix::query_pagesize(p);
 492         if (real_pagesize != pagesize) {
 493           trcVerbose("real page size (" SIZE_FORMAT_HEX ") differs.", real_pagesize);
 494         } else {
 495           can_use = true;
 496         }
 497         ::shmdt(p);
 498       }
 499       trcVerbose("Can use: %s", (can_use ? "yes" : "no"));
 500       if (pagesize == 64*K) {
 501         g_multipage_support.can_use_64K_pages = can_use;
 502       } else if (pagesize == 16*M) {
 503         g_multipage_support.can_use_16M_pages = can_use;
 504       }
 505     }
 506 
 507   } // end: check which pages can be used for shared memory
 508 
 509 query_multipage_support_end:
 510 
 511   trcVerbose("base page size (sysconf _SC_PAGESIZE): %s",
 512       describe_pagesize(g_multipage_support.pagesize));
 513   trcVerbose("Data page size (C-Heap, bss, etc): %s",
 514       describe_pagesize(g_multipage_support.datapsize));
 515   trcVerbose("Text page size: %s",
 516       describe_pagesize(g_multipage_support.textpsize));
 517   trcVerbose("Thread stack page size (pthread): %s",
 518       describe_pagesize(g_multipage_support.pthr_stack_pagesize));
 519   trcVerbose("Default shared memory page size: %s",
 520       describe_pagesize(g_multipage_support.shmpsize));
 521   trcVerbose("Can use 64K pages dynamically with shared memory: %s",
 522       (g_multipage_support.can_use_64K_pages ? "yes" :"no"));
 523   trcVerbose("Can use 16M pages dynamically with shared memory: %s",
 524       (g_multipage_support.can_use_16M_pages ? "yes" :"no"));
 525   trcVerbose("Multipage error details: %d",
 526       g_multipage_support.error);
 527 
 528   // sanity checks
 529   assert0(g_multipage_support.pagesize == 4*K);
 530   assert0(g_multipage_support.datapsize == 4*K || g_multipage_support.datapsize == 64*K);
 531   assert0(g_multipage_support.textpsize == 4*K || g_multipage_support.textpsize == 64*K);
 532   assert0(g_multipage_support.pthr_stack_pagesize == g_multipage_support.datapsize);
 533   assert0(g_multipage_support.shmpsize == 4*K || g_multipage_support.shmpsize == 64*K);
 534 
 535 }
 536 
 537 void os::init_system_properties_values() {
 538 
 539 #ifndef OVERRIDE_LIBPATH
 540   #define DEFAULT_LIBPATH "/lib:/usr/lib"
 541 #else
 542   #define DEFAULT_LIBPATH OVERRIDE_LIBPATH
 543 #endif
 544 #define EXTENSIONS_DIR  "/lib/ext"
 545 
 546   // Buffer that fits several sprintfs.
 547   // Note that the space for the trailing null is provided
 548   // by the nulls included by the sizeof operator.
 549   const size_t bufsize =
 550     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 551          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR)); // extensions dir
 552   char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 553 
 554   // sysclasspath, java_home, dll_dir
 555   {
 556     char *pslash;
 557     os::jvm_path(buf, bufsize);
 558 
 559     // Found the full path to libjvm.so.
 560     // Now cut the path to <java_home>/jre if we can.
 561     pslash = strrchr(buf, '/');
 562     if (pslash != NULL) {
 563       *pslash = '\0';            // Get rid of /libjvm.so.
 564     }
 565     pslash = strrchr(buf, '/');
 566     if (pslash != NULL) {
 567       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 568     }
 569     Arguments::set_dll_dir(buf);
 570 
 571     if (pslash != NULL) {
 572       pslash = strrchr(buf, '/');
 573       if (pslash != NULL) {
 574         *pslash = '\0';        // Get rid of /lib.
 575       }
 576     }
 577     Arguments::set_java_home(buf);
 578     if (!set_boot_path('/', ':')) {
 579       vm_exit_during_initialization("Failed setting boot class path.", NULL);
 580     }
 581   }
 582 
 583   // Where to look for native libraries.
 584 
 585   // On Aix we get the user setting of LIBPATH.
 586   // Eventually, all the library path setting will be done here.
 587   // Get the user setting of LIBPATH.
 588   const char *v = ::getenv("LIBPATH");
 589   const char *v_colon = ":";
 590   if (v == NULL) { v = ""; v_colon = ""; }
 591 
 592   // Concatenate user and invariant part of ld_library_path.
 593   // That's +1 for the colon and +1 for the trailing '\0'.
 594   char *ld_library_path = NEW_C_HEAP_ARRAY(char, strlen(v) + 1 + sizeof(DEFAULT_LIBPATH) + 1, mtInternal);
 595   sprintf(ld_library_path, "%s%s" DEFAULT_LIBPATH, v, v_colon);
 596   Arguments::set_library_path(ld_library_path);
 597   FREE_C_HEAP_ARRAY(char, ld_library_path);
 598 
 599   // Extensions directories.
 600   sprintf(buf, "%s" EXTENSIONS_DIR, Arguments::get_java_home());
 601   Arguments::set_ext_dirs(buf);
 602 
 603   FREE_C_HEAP_ARRAY(char, buf);
 604 
 605 #undef DEFAULT_LIBPATH
 606 #undef EXTENSIONS_DIR
 607 }
 608 
 609 ////////////////////////////////////////////////////////////////////////////////
 610 // breakpoint support
 611 
 612 void os::breakpoint() {
 613   BREAKPOINT;
 614 }
 615 
 616 extern "C" void breakpoint() {
 617   // use debugger to set breakpoint here
 618 }
 619 
 620 ////////////////////////////////////////////////////////////////////////////////
 621 // signal support
 622 
 623 debug_only(static bool signal_sets_initialized = false);
 624 static sigset_t unblocked_sigs, vm_sigs;
 625 
 626 void os::Aix::signal_sets_init() {
 627   // Should also have an assertion stating we are still single-threaded.
 628   assert(!signal_sets_initialized, "Already initialized");
 629   // Fill in signals that are necessarily unblocked for all threads in
 630   // the VM. Currently, we unblock the following signals:
 631   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 632   //                         by -Xrs (=ReduceSignalUsage));
 633   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 634   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 635   // the dispositions or masks wrt these signals.
 636   // Programs embedding the VM that want to use the above signals for their
 637   // own purposes must, at this time, use the "-Xrs" option to prevent
 638   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 639   // (See bug 4345157, and other related bugs).
 640   // In reality, though, unblocking these signals is really a nop, since
 641   // these signals are not blocked by default.
 642   sigemptyset(&unblocked_sigs);
 643   sigaddset(&unblocked_sigs, SIGILL);
 644   sigaddset(&unblocked_sigs, SIGSEGV);
 645   sigaddset(&unblocked_sigs, SIGBUS);
 646   sigaddset(&unblocked_sigs, SIGFPE);
 647   sigaddset(&unblocked_sigs, SIGTRAP);
 648   sigaddset(&unblocked_sigs, SR_signum);
 649 
 650   if (!ReduceSignalUsage) {
 651    if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 652      sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 653    }
 654    if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 655      sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 656    }
 657    if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 658      sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 659    }
 660   }
 661   // Fill in signals that are blocked by all but the VM thread.
 662   sigemptyset(&vm_sigs);
 663   if (!ReduceSignalUsage)
 664     sigaddset(&vm_sigs, BREAK_SIGNAL);
 665   debug_only(signal_sets_initialized = true);
 666 }
 667 
 668 // These are signals that are unblocked while a thread is running Java.
 669 // (For some reason, they get blocked by default.)
 670 sigset_t* os::Aix::unblocked_signals() {
 671   assert(signal_sets_initialized, "Not initialized");
 672   return &unblocked_sigs;
 673 }
 674 
 675 // These are the signals that are blocked while a (non-VM) thread is
 676 // running Java. Only the VM thread handles these signals.
 677 sigset_t* os::Aix::vm_signals() {
 678   assert(signal_sets_initialized, "Not initialized");
 679   return &vm_sigs;
 680 }
 681 
 682 void os::Aix::hotspot_sigmask(Thread* thread) {
 683 
 684   //Save caller's signal mask before setting VM signal mask
 685   sigset_t caller_sigmask;
 686   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 687 
 688   OSThread* osthread = thread->osthread();
 689   osthread->set_caller_sigmask(caller_sigmask);
 690 
 691   pthread_sigmask(SIG_UNBLOCK, os::Aix::unblocked_signals(), NULL);
 692 
 693   if (!ReduceSignalUsage) {
 694     if (thread->is_VM_thread()) {
 695       // Only the VM thread handles BREAK_SIGNAL ...
 696       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 697     } else {
 698       // ... all other threads block BREAK_SIGNAL
 699       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 700     }
 701   }
 702 }
 703 
 704 // retrieve memory information.
 705 // Returns false if something went wrong;
 706 // content of pmi undefined in this case.
 707 bool os::Aix::get_meminfo(meminfo_t* pmi) {
 708 
 709   assert(pmi, "get_meminfo: invalid parameter");
 710 
 711   memset(pmi, 0, sizeof(meminfo_t));
 712 
 713   if (os::Aix::on_pase()) {
 714     // On PASE, use the libo4 porting library.
 715 
 716     unsigned long long virt_total = 0;
 717     unsigned long long real_total = 0;
 718     unsigned long long real_free = 0;
 719     unsigned long long pgsp_total = 0;
 720     unsigned long long pgsp_free = 0;
 721     if (libo4::get_memory_info(&virt_total, &real_total, &real_free, &pgsp_total, &pgsp_free)) {
 722       pmi->virt_total = virt_total;
 723       pmi->real_total = real_total;
 724       pmi->real_free = real_free;
 725       pmi->pgsp_total = pgsp_total;
 726       pmi->pgsp_free = pgsp_free;
 727       return true;
 728     }
 729     return false;
 730 
 731   } else {
 732 
 733     // On AIX, I use the (dynamically loaded) perfstat library to retrieve memory statistics
 734     // See:
 735     // http://publib.boulder.ibm.com/infocenter/systems/index.jsp
 736     //        ?topic=/com.ibm.aix.basetechref/doc/basetrf1/perfstat_memtot.htm
 737     // http://publib.boulder.ibm.com/infocenter/systems/index.jsp
 738     //        ?topic=/com.ibm.aix.files/doc/aixfiles/libperfstat.h.htm
 739 
 740     perfstat_memory_total_t psmt;
 741     memset (&psmt, '\0', sizeof(psmt));
 742     const int rc = libperfstat::perfstat_memory_total(NULL, &psmt, sizeof(psmt), 1);
 743     if (rc == -1) {
 744       trcVerbose("perfstat_memory_total() failed (errno=%d)", errno);
 745       assert(0, "perfstat_memory_total() failed");
 746       return false;
 747     }
 748 
 749     assert(rc == 1, "perfstat_memory_total() - weird return code");
 750 
 751     // excerpt from
 752     // http://publib.boulder.ibm.com/infocenter/systems/index.jsp
 753     //        ?topic=/com.ibm.aix.files/doc/aixfiles/libperfstat.h.htm
 754     // The fields of perfstat_memory_total_t:
 755     // u_longlong_t virt_total         Total virtual memory (in 4 KB pages).
 756     // u_longlong_t real_total         Total real memory (in 4 KB pages).
 757     // u_longlong_t real_free          Free real memory (in 4 KB pages).
 758     // u_longlong_t pgsp_total         Total paging space (in 4 KB pages).
 759     // u_longlong_t pgsp_free          Free paging space (in 4 KB pages).
 760 
 761     pmi->virt_total = psmt.virt_total * 4096;
 762     pmi->real_total = psmt.real_total * 4096;
 763     pmi->real_free = psmt.real_free * 4096;
 764     pmi->pgsp_total = psmt.pgsp_total * 4096;
 765     pmi->pgsp_free = psmt.pgsp_free * 4096;
 766 
 767     return true;
 768 
 769   }
 770 } // end os::Aix::get_meminfo
 771 
 772 //////////////////////////////////////////////////////////////////////////////
 773 // create new thread
 774 
 775 // Thread start routine for all newly created threads
 776 static void *thread_native_entry(Thread *thread) {
 777 
 778   thread->record_stack_base_and_size();
 779 
 780   const pthread_t pthread_id = ::pthread_self();
 781   const tid_t kernel_thread_id = ::thread_self();
 782 
 783   LogTarget(Info, os, thread) lt;
 784   if (lt.is_enabled()) {
 785     address low_address = thread->stack_end();
 786     address high_address = thread->stack_base();
 787     lt.print("Thread is alive (tid: " UINTX_FORMAT ", kernel thread id: " UINTX_FORMAT
 788              ", stack [" PTR_FORMAT " - " PTR_FORMAT " (" SIZE_FORMAT "k using %uk pages)).",
 789              os::current_thread_id(), (uintx) kernel_thread_id, low_address, high_address,
 790              (high_address - low_address) / K, os::Aix::query_pagesize(low_address) / K);
 791   }
 792 
 793   // Normally, pthread stacks on AIX live in the data segment (are allocated with malloc()
 794   // by the pthread library). In rare cases, this may not be the case, e.g. when third-party
 795   // tools hook pthread_create(). In this case, we may run into problems establishing
 796   // guard pages on those stacks, because the stacks may reside in memory which is not
 797   // protectable (shmated).
 798   if (thread->stack_base() > ::sbrk(0)) {
 799     log_warning(os, thread)("Thread stack not in data segment.");
 800   }
 801 
 802   // Try to randomize the cache line index of hot stack frames.
 803   // This helps when threads of the same stack traces evict each other's
 804   // cache lines. The threads can be either from the same JVM instance, or
 805   // from different JVM instances. The benefit is especially true for
 806   // processors with hyperthreading technology.
 807 
 808   static int counter = 0;
 809   int pid = os::current_process_id();
 810   alloca(((pid ^ counter++) & 7) * 128);
 811 
 812   thread->initialize_thread_current();
 813 
 814   OSThread* osthread = thread->osthread();
 815 
 816   // Thread_id is pthread id.
 817   osthread->set_thread_id(pthread_id);
 818 
 819   // .. but keep kernel thread id too for diagnostics
 820   osthread->set_kernel_thread_id(kernel_thread_id);
 821 
 822   // Initialize signal mask for this thread.
 823   os::Aix::hotspot_sigmask(thread);
 824 
 825   // Initialize floating point control register.
 826   os::Aix::init_thread_fpu_state();
 827 
 828   assert(osthread->get_state() == RUNNABLE, "invalid os thread state");
 829 
 830   // Call one more level start routine.
 831   thread->call_run();
 832 
 833   // Note: at this point the thread object may already have deleted itself.
 834   // Prevent dereferencing it from here on out.
 835   thread = NULL;
 836 
 837   log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", kernel thread id: " UINTX_FORMAT ").",
 838     os::current_thread_id(), (uintx) kernel_thread_id);
 839 
 840   return 0;
 841 }
 842 
 843 bool os::create_thread(Thread* thread, ThreadType thr_type,
 844                        size_t req_stack_size) {
 845 
 846   assert(thread->osthread() == NULL, "caller responsible");
 847 
 848   // Allocate the OSThread object.
 849   OSThread* osthread = new OSThread(NULL, NULL);
 850   if (osthread == NULL) {
 851     return false;
 852   }
 853 
 854   // Set the correct thread state.
 855   osthread->set_thread_type(thr_type);
 856 
 857   // Initial state is ALLOCATED but not INITIALIZED
 858   osthread->set_state(ALLOCATED);
 859 
 860   thread->set_osthread(osthread);
 861 
 862   // Init thread attributes.
 863   pthread_attr_t attr;
 864   pthread_attr_init(&attr);
 865   guarantee(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) == 0, "???");
 866 
 867   // Make sure we run in 1:1 kernel-user-thread mode.
 868   if (os::Aix::on_aix()) {
 869     guarantee(pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM) == 0, "???");
 870     guarantee(pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED) == 0, "???");
 871   }
 872 
 873   // Start in suspended state, and in os::thread_start, wake the thread up.
 874   guarantee(pthread_attr_setsuspendstate_np(&attr, PTHREAD_CREATE_SUSPENDED_NP) == 0, "???");
 875 
 876   // Calculate stack size if it's not specified by caller.
 877   size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
 878 
 879   // JDK-8187028: It was observed that on some configurations (4K backed thread stacks)
 880   // the real thread stack size may be smaller than the requested stack size, by as much as 64K.
 881   // This very much looks like a pthread lib error. As a workaround, increase the stack size
 882   // by 64K for small thread stacks (arbitrarily choosen to be < 4MB)
 883   if (stack_size < 4096 * K) {
 884     stack_size += 64 * K;
 885   }
 886 
 887   // On Aix, pthread_attr_setstacksize fails with huge values and leaves the
 888   // thread size in attr unchanged. If this is the minimal stack size as set
 889   // by pthread_attr_init this leads to crashes after thread creation. E.g. the
 890   // guard pages might not fit on the tiny stack created.
 891   int ret = pthread_attr_setstacksize(&attr, stack_size);
 892   if (ret != 0) {
 893     log_warning(os, thread)("The %sthread stack size specified is invalid: " SIZE_FORMAT "k",
 894                             (thr_type == compiler_thread) ? "compiler " : ((thr_type == java_thread) ? "" : "VM "),
 895                             stack_size / K);
 896     thread->set_osthread(NULL);
 897     delete osthread;
 898     return false;
 899   }
 900 
 901   // Save some cycles and a page by disabling OS guard pages where we have our own
 902   // VM guard pages (in java threads). For other threads, keep system default guard
 903   // pages in place.
 904   if (thr_type == java_thread || thr_type == compiler_thread) {
 905     ret = pthread_attr_setguardsize(&attr, 0);
 906   }
 907 
 908   pthread_t tid = 0;
 909   if (ret == 0) {
 910     ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
 911   }
 912 
 913   if (ret == 0) {
 914     char buf[64];
 915     log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
 916       (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 917   } else {
 918     char buf[64];
 919     log_warning(os, thread)("Failed to start thread - pthread_create failed (%d=%s) for attributes: %s.",
 920       ret, os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 921     // Log some OS information which might explain why creating the thread failed.
 922     log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
 923     LogStream st(Log(os, thread)::info());
 924     os::Posix::print_rlimit_info(&st);
 925     os::print_memory_info(&st);
 926   }
 927 
 928   pthread_attr_destroy(&attr);
 929 
 930   if (ret != 0) {
 931     // Need to clean up stuff we've allocated so far.
 932     thread->set_osthread(NULL);
 933     delete osthread;
 934     return false;
 935   }
 936 
 937   // OSThread::thread_id is the pthread id.
 938   osthread->set_thread_id(tid);
 939 
 940   return true;
 941 }
 942 
 943 /////////////////////////////////////////////////////////////////////////////
 944 // attach existing thread
 945 
 946 // bootstrap the main thread
 947 bool os::create_main_thread(JavaThread* thread) {
 948   assert(os::Aix::_main_thread == pthread_self(), "should be called inside main thread");
 949   return create_attached_thread(thread);
 950 }
 951 
 952 bool os::create_attached_thread(JavaThread* thread) {
 953 #ifdef ASSERT
 954     thread->verify_not_published();
 955 #endif
 956 
 957   // Allocate the OSThread object
 958   OSThread* osthread = new OSThread(NULL, NULL);
 959 
 960   if (osthread == NULL) {
 961     return false;
 962   }
 963 
 964   const pthread_t pthread_id = ::pthread_self();
 965   const tid_t kernel_thread_id = ::thread_self();
 966 
 967   // OSThread::thread_id is the pthread id.
 968   osthread->set_thread_id(pthread_id);
 969 
 970   // .. but keep kernel thread id too for diagnostics
 971   osthread->set_kernel_thread_id(kernel_thread_id);
 972 
 973   // initialize floating point control register
 974   os::Aix::init_thread_fpu_state();
 975 
 976   // Initial thread state is RUNNABLE
 977   osthread->set_state(RUNNABLE);
 978 
 979   thread->set_osthread(osthread);
 980 
 981   if (UseNUMA) {
 982     int lgrp_id = os::numa_get_group_id();
 983     if (lgrp_id != -1) {
 984       thread->set_lgrp_id(lgrp_id);
 985     }
 986   }
 987 
 988   // initialize signal mask for this thread
 989   // and save the caller's signal mask
 990   os::Aix::hotspot_sigmask(thread);
 991 
 992   log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", kernel thread id: " UINTX_FORMAT ").",
 993     os::current_thread_id(), (uintx) kernel_thread_id);
 994 
 995   return true;
 996 }
 997 
 998 void os::pd_start_thread(Thread* thread) {
 999   int status = pthread_continue_np(thread->osthread()->pthread_id());
1000   assert(status == 0, "thr_continue failed");
1001 }
1002 
1003 // Free OS resources related to the OSThread
1004 void os::free_thread(OSThread* osthread) {
1005   assert(osthread != NULL, "osthread not set");
1006 
1007   // We are told to free resources of the argument thread,
1008   // but we can only really operate on the current thread.
1009   assert(Thread::current()->osthread() == osthread,
1010          "os::free_thread but not current thread");
1011 
1012   // Restore caller's signal mask
1013   sigset_t sigmask = osthread->caller_sigmask();
1014   pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
1015 
1016   delete osthread;
1017 }
1018 
1019 ////////////////////////////////////////////////////////////////////////////////
1020 // time support
1021 
1022 // Time since start-up in seconds to a fine granularity.
1023 // Used by VMSelfDestructTimer and the MemProfiler.
1024 double os::elapsedTime() {
1025   return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution
1026 }
1027 
1028 jlong os::elapsed_counter() {
1029   return javaTimeNanos() - initial_time_count;
1030 }
1031 
1032 jlong os::elapsed_frequency() {
1033   return NANOSECS_PER_SEC; // nanosecond resolution
1034 }
1035 
1036 bool os::supports_vtime() { return true; }
1037 
1038 double os::elapsedVTime() {
1039   struct rusage usage;
1040   int retval = getrusage(RUSAGE_THREAD, &usage);
1041   if (retval == 0) {
1042     return usage.ru_utime.tv_sec + usage.ru_stime.tv_sec + (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000.0 * 1000);
1043   } else {
1044     // better than nothing, but not much
1045     return elapsedTime();
1046   }
1047 }
1048 
1049 jlong os::javaTimeMillis() {
1050   timeval time;
1051   int status = gettimeofday(&time, NULL);
1052   assert(status != -1, "aix error at gettimeofday()");
1053   return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
1054 }
1055 
1056 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
1057   timeval time;
1058   int status = gettimeofday(&time, NULL);
1059   assert(status != -1, "aix error at gettimeofday()");
1060   seconds = jlong(time.tv_sec);
1061   nanos = jlong(time.tv_usec) * 1000;
1062 }
1063 
1064 // We use mread_real_time here.
1065 // On AIX: If the CPU has a time register, the result will be RTC_POWER and
1066 // it has to be converted to real time. AIX documentations suggests to do
1067 // this unconditionally, so we do it.
1068 //
1069 // See: https://www.ibm.com/support/knowledgecenter/ssw_aix_61/com.ibm.aix.basetrf2/read_real_time.htm
1070 //
1071 // On PASE: mread_real_time will always return RTC_POWER_PC data, so no
1072 // conversion is necessary. However, mread_real_time will not return
1073 // monotonic results but merely matches read_real_time. So we need a tweak
1074 // to ensure monotonic results.
1075 //
1076 // For PASE no public documentation exists, just word by IBM
1077 jlong os::javaTimeNanos() {
1078   timebasestruct_t time;
1079   int rc = mread_real_time(&time, TIMEBASE_SZ);
1080   if (os::Aix::on_pase()) {
1081     assert(rc == RTC_POWER, "expected time format RTC_POWER from mread_real_time in PASE");
1082     jlong now = jlong(time.tb_high) * NANOSECS_PER_SEC + jlong(time.tb_low);
1083     jlong prev = max_real_time;
1084     if (now <= prev) {
1085       return prev;   // same or retrograde time;
1086     }
1087     jlong obsv = Atomic::cmpxchg(now, &max_real_time, prev);
1088     assert(obsv >= prev, "invariant");   // Monotonicity
1089     // If the CAS succeeded then we're done and return "now".
1090     // If the CAS failed and the observed value "obsv" is >= now then
1091     // we should return "obsv".  If the CAS failed and now > obsv > prv then
1092     // some other thread raced this thread and installed a new value, in which case
1093     // we could either (a) retry the entire operation, (b) retry trying to install now
1094     // or (c) just return obsv.  We use (c).   No loop is required although in some cases
1095     // we might discard a higher "now" value in deference to a slightly lower but freshly
1096     // installed obsv value.   That's entirely benign -- it admits no new orderings compared
1097     // to (a) or (b) -- and greatly reduces coherence traffic.
1098     // We might also condition (c) on the magnitude of the delta between obsv and now.
1099     // Avoiding excessive CAS operations to hot RW locations is critical.
1100     // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1101     return (prev == obsv) ? now : obsv;
1102   } else {
1103     if (rc != RTC_POWER) {
1104       rc = time_base_to_time(&time, TIMEBASE_SZ);
1105       assert(rc != -1, "error calling time_base_to_time()");
1106     }
1107     return jlong(time.tb_high) * NANOSECS_PER_SEC + jlong(time.tb_low);
1108   }
1109 }
1110 
1111 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1112   info_ptr->max_value = ALL_64_BITS;
1113   // mread_real_time() is monotonic (see 'os::javaTimeNanos()')
1114   info_ptr->may_skip_backward = false;
1115   info_ptr->may_skip_forward = false;
1116   info_ptr->kind = JVMTI_TIMER_ELAPSED;    // elapsed not CPU time
1117 }
1118 
1119 // Return the real, user, and system times in seconds from an
1120 // arbitrary fixed point in the past.
1121 bool os::getTimesSecs(double* process_real_time,
1122                       double* process_user_time,
1123                       double* process_system_time) {
1124   struct tms ticks;
1125   clock_t real_ticks = times(&ticks);
1126 
1127   if (real_ticks == (clock_t) (-1)) {
1128     return false;
1129   } else {
1130     double ticks_per_second = (double) clock_tics_per_sec;
1131     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1132     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1133     *process_real_time = ((double) real_ticks) / ticks_per_second;
1134 
1135     return true;
1136   }
1137 }
1138 
1139 char * os::local_time_string(char *buf, size_t buflen) {
1140   struct tm t;
1141   time_t long_time;
1142   time(&long_time);
1143   localtime_r(&long_time, &t);
1144   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1145                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1146                t.tm_hour, t.tm_min, t.tm_sec);
1147   return buf;
1148 }
1149 
1150 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1151   return localtime_r(clock, res);
1152 }
1153 
1154 ////////////////////////////////////////////////////////////////////////////////
1155 // runtime exit support
1156 
1157 // Note: os::shutdown() might be called very early during initialization, or
1158 // called from signal handler. Before adding something to os::shutdown(), make
1159 // sure it is async-safe and can handle partially initialized VM.
1160 void os::shutdown() {
1161 
1162   // allow PerfMemory to attempt cleanup of any persistent resources
1163   perfMemory_exit();
1164 
1165   // needs to remove object in file system
1166   AttachListener::abort();
1167 
1168   // flush buffered output, finish log files
1169   ostream_abort();
1170 
1171   // Check for abort hook
1172   abort_hook_t abort_hook = Arguments::abort_hook();
1173   if (abort_hook != NULL) {
1174     abort_hook();
1175   }
1176 }
1177 
1178 // Note: os::abort() might be called very early during initialization, or
1179 // called from signal handler. Before adding something to os::abort(), make
1180 // sure it is async-safe and can handle partially initialized VM.
1181 void os::abort(bool dump_core, void* siginfo, const void* context) {
1182   os::shutdown();
1183   if (dump_core) {
1184 #ifndef PRODUCT
1185     fdStream out(defaultStream::output_fd());
1186     out.print_raw("Current thread is ");
1187     char buf[16];
1188     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1189     out.print_raw_cr(buf);
1190     out.print_raw_cr("Dumping core ...");
1191 #endif
1192     ::abort(); // dump core
1193   }
1194 
1195   ::exit(1);
1196 }
1197 
1198 // Die immediately, no exit hook, no abort hook, no cleanup.
1199 // Dump a core file, if possible, for debugging.
1200 void os::die() {
1201   if (TestUnresponsiveErrorHandler && !CreateCoredumpOnCrash) {
1202     // For TimeoutInErrorHandlingTest.java, we just kill the VM
1203     // and don't take the time to generate a core file.
1204     os::signal_raise(SIGKILL);
1205   } else {
1206     ::abort();
1207   }
1208 }
1209 
1210 intx os::current_thread_id() {
1211   return (intx)pthread_self();
1212 }
1213 
1214 int os::current_process_id() {
1215   return getpid();
1216 }
1217 
1218 // DLL functions
1219 
1220 const char* os::dll_file_extension() { return ".so"; }
1221 
1222 // This must be hard coded because it's the system's temporary
1223 // directory not the java application's temp directory, ala java.io.tmpdir.
1224 const char* os::get_temp_directory() { return "/tmp"; }
1225 
1226 // Check if addr is inside libjvm.so.
1227 bool os::address_is_in_vm(address addr) {
1228 
1229   // Input could be a real pc or a function pointer literal. The latter
1230   // would be a function descriptor residing in the data segment of a module.
1231   loaded_module_t lm;
1232   if (LoadedLibraries::find_for_text_address(addr, &lm) != NULL) {
1233     return lm.is_in_vm;
1234   } else if (LoadedLibraries::find_for_data_address(addr, &lm) != NULL) {
1235     return lm.is_in_vm;
1236   } else {
1237     return false;
1238   }
1239 
1240 }
1241 
1242 // Resolve an AIX function descriptor literal to a code pointer.
1243 // If the input is a valid code pointer to a text segment of a loaded module,
1244 //   it is returned unchanged.
1245 // If the input is a valid AIX function descriptor, it is resolved to the
1246 //   code entry point.
1247 // If the input is neither a valid function descriptor nor a valid code pointer,
1248 //   NULL is returned.
1249 static address resolve_function_descriptor_to_code_pointer(address p) {
1250 
1251   if (LoadedLibraries::find_for_text_address(p, NULL) != NULL) {
1252     // It is a real code pointer.
1253     return p;
1254   } else if (LoadedLibraries::find_for_data_address(p, NULL) != NULL) {
1255     // Pointer to data segment, potential function descriptor.
1256     address code_entry = (address)(((FunctionDescriptor*)p)->entry());
1257     if (LoadedLibraries::find_for_text_address(code_entry, NULL) != NULL) {
1258       // It is a function descriptor.
1259       return code_entry;
1260     }
1261   }
1262 
1263   return NULL;
1264 }
1265 
1266 bool os::dll_address_to_function_name(address addr, char *buf,
1267                                       int buflen, int *offset,
1268                                       bool demangle) {
1269   if (offset) {
1270     *offset = -1;
1271   }
1272   // Buf is not optional, but offset is optional.
1273   assert(buf != NULL, "sanity check");
1274   buf[0] = '\0';
1275 
1276   // Resolve function ptr literals first.
1277   addr = resolve_function_descriptor_to_code_pointer(addr);
1278   if (!addr) {
1279     return false;
1280   }
1281 
1282   return AixSymbols::get_function_name(addr, buf, buflen, offset, NULL, demangle);
1283 }
1284 
1285 bool os::dll_address_to_library_name(address addr, char* buf,
1286                                      int buflen, int* offset) {
1287   if (offset) {
1288     *offset = -1;
1289   }
1290   // Buf is not optional, but offset is optional.
1291   assert(buf != NULL, "sanity check");
1292   buf[0] = '\0';
1293 
1294   // Resolve function ptr literals first.
1295   addr = resolve_function_descriptor_to_code_pointer(addr);
1296   if (!addr) {
1297     return false;
1298   }
1299 
1300   return AixSymbols::get_module_name(addr, buf, buflen);
1301 }
1302 
1303 // Loads .dll/.so and in case of error it checks if .dll/.so was built
1304 // for the same architecture as Hotspot is running on.
1305 void *os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1306 
1307   log_info(os)("attempting shared library load of %s", filename);
1308 
1309   if (ebuf && ebuflen > 0) {
1310     ebuf[0] = '\0';
1311     ebuf[ebuflen - 1] = '\0';
1312   }
1313 
1314   if (!filename || strlen(filename) == 0) {
1315     ::strncpy(ebuf, "dll_load: empty filename specified", ebuflen - 1);
1316     return NULL;
1317   }
1318 
1319   // RTLD_LAZY is currently not implemented. The dl is loaded immediately with all its dependants.
1320   void * result= ::dlopen(filename, RTLD_LAZY);
1321   if (result != NULL) {
1322     Events::log(NULL, "Loaded shared library %s", filename);
1323     // Reload dll cache. Don't do this in signal handling.
1324     LoadedLibraries::reload();
1325     log_info(os)("shared library load of %s was successful", filename);
1326     return result;
1327   } else {
1328     // error analysis when dlopen fails
1329     const char* error_report = ::dlerror();
1330     if (error_report == NULL) {
1331       error_report = "dlerror returned no error description";
1332     }
1333     if (ebuf != NULL && ebuflen > 0) {
1334       snprintf(ebuf, ebuflen - 1, "%s, LIBPATH=%s, LD_LIBRARY_PATH=%s : %s",
1335                filename, ::getenv("LIBPATH"), ::getenv("LD_LIBRARY_PATH"), error_report);
1336     }
1337     Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
1338     log_info(os)("shared library load of %s failed, %s", filename, error_report);
1339   }
1340   return NULL;
1341 }
1342 
1343 void* os::dll_lookup(void* handle, const char* name) {
1344   void* res = dlsym(handle, name);
1345   return res;
1346 }
1347 
1348 void* os::get_default_process_handle() {
1349   return (void*)::dlopen(NULL, RTLD_LAZY);
1350 }
1351 
1352 void os::print_dll_info(outputStream *st) {
1353   st->print_cr("Dynamic libraries:");
1354   LoadedLibraries::print(st);
1355 }
1356 
1357 void os::get_summary_os_info(char* buf, size_t buflen) {
1358   // There might be something more readable than uname results for AIX.
1359   struct utsname name;
1360   uname(&name);
1361   snprintf(buf, buflen, "%s %s", name.release, name.version);
1362 }
1363 
1364 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1365   // Not yet implemented.
1366   return 0;
1367 }
1368 
1369 void os::print_os_info_brief(outputStream* st) {
1370   uint32_t ver = os::Aix::os_version();
1371   st->print_cr("AIX kernel version %u.%u.%u.%u",
1372                (ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
1373 
1374   os::Posix::print_uname_info(st);
1375 
1376   // Linux uses print_libversion_info(st); here.
1377 }
1378 
1379 void os::print_os_info(outputStream* st) {
1380   st->print("OS:");
1381 
1382   os::Posix::print_uname_info(st);
1383 
1384   uint32_t ver = os::Aix::os_version();
1385   st->print_cr("AIX kernel version %u.%u.%u.%u",
1386                (ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
1387 
1388   os::Posix::print_uptime_info(st);
1389 
1390   os::Posix::print_rlimit_info(st);
1391 
1392   os::Posix::print_load_average(st);
1393 
1394   // _SC_THREAD_THREADS_MAX is the maximum number of threads within a process.
1395   long tmax = sysconf(_SC_THREAD_THREADS_MAX);
1396   st->print_cr("maximum #threads within a process:%ld", tmax);
1397 
1398   // print wpar info
1399   libperfstat::wparinfo_t wi;
1400   if (libperfstat::get_wparinfo(&wi)) {
1401     st->print_cr("wpar info");
1402     st->print_cr("name: %s", wi.name);
1403     st->print_cr("id:   %d", wi.wpar_id);
1404     st->print_cr("type: %s", (wi.app_wpar ? "application" : "system"));
1405   }
1406 
1407   VM_Version::print_platform_virtualization_info(st);
1408 }
1409 
1410 void os::print_memory_info(outputStream* st) {
1411 
1412   st->print_cr("Memory:");
1413 
1414   st->print_cr("  Base page size (sysconf _SC_PAGESIZE):  %s",
1415     describe_pagesize(g_multipage_support.pagesize));
1416   st->print_cr("  Data page size (C-Heap, bss, etc):      %s",
1417     describe_pagesize(g_multipage_support.datapsize));
1418   st->print_cr("  Text page size:                         %s",
1419     describe_pagesize(g_multipage_support.textpsize));
1420   st->print_cr("  Thread stack page size (pthread):       %s",
1421     describe_pagesize(g_multipage_support.pthr_stack_pagesize));
1422   st->print_cr("  Default shared memory page size:        %s",
1423     describe_pagesize(g_multipage_support.shmpsize));
1424   st->print_cr("  Can use 64K pages dynamically with shared memory:  %s",
1425     (g_multipage_support.can_use_64K_pages ? "yes" :"no"));
1426   st->print_cr("  Can use 16M pages dynamically with shared memory: %s",
1427     (g_multipage_support.can_use_16M_pages ? "yes" :"no"));
1428   st->print_cr("  Multipage error: %d",
1429     g_multipage_support.error);
1430   st->cr();
1431   st->print_cr("  os::vm_page_size:       %s", describe_pagesize(os::vm_page_size()));
1432 
1433   // print out LDR_CNTRL because it affects the default page sizes
1434   const char* const ldr_cntrl = ::getenv("LDR_CNTRL");
1435   st->print_cr("  LDR_CNTRL=%s.", ldr_cntrl ? ldr_cntrl : "<unset>");
1436 
1437   // Print out EXTSHM because it is an unsupported setting.
1438   const char* const extshm = ::getenv("EXTSHM");
1439   st->print_cr("  EXTSHM=%s.", extshm ? extshm : "<unset>");
1440   if ( (strcmp(extshm, "on") == 0) || (strcmp(extshm, "ON") == 0) ) {
1441     st->print_cr("  *** Unsupported! Please remove EXTSHM from your environment! ***");
1442   }
1443 
1444   // Print out AIXTHREAD_GUARDPAGES because it affects the size of pthread stacks.
1445   const char* const aixthread_guardpages = ::getenv("AIXTHREAD_GUARDPAGES");
1446   st->print_cr("  AIXTHREAD_GUARDPAGES=%s.",
1447       aixthread_guardpages ? aixthread_guardpages : "<unset>");
1448   st->cr();
1449 
1450   os::Aix::meminfo_t mi;
1451   if (os::Aix::get_meminfo(&mi)) {
1452     if (os::Aix::on_aix()) {
1453       st->print_cr("physical total : " SIZE_FORMAT, mi.real_total);
1454       st->print_cr("physical free  : " SIZE_FORMAT, mi.real_free);
1455       st->print_cr("swap total     : " SIZE_FORMAT, mi.pgsp_total);
1456       st->print_cr("swap free      : " SIZE_FORMAT, mi.pgsp_free);
1457     } else {
1458       // PASE - Numbers are result of QWCRSSTS; they mean:
1459       // real_total: Sum of all system pools
1460       // real_free: always 0
1461       // pgsp_total: we take the size of the system ASP
1462       // pgsp_free: size of system ASP times percentage of system ASP unused
1463       st->print_cr("physical total     : " SIZE_FORMAT, mi.real_total);
1464       st->print_cr("system asp total   : " SIZE_FORMAT, mi.pgsp_total);
1465       st->print_cr("%% system asp used : %.2f",
1466         mi.pgsp_total ? (100.0f * (mi.pgsp_total - mi.pgsp_free) / mi.pgsp_total) : -1.0f);
1467     }
1468   }
1469   st->cr();
1470 
1471   // Print program break.
1472   st->print_cr("Program break at VM startup: " PTR_FORMAT ".", p2i(g_brk_at_startup));
1473   address brk_now = (address)::sbrk(0);
1474   if (brk_now != (address)-1) {
1475     st->print_cr("Program break now          : " PTR_FORMAT " (distance: " SIZE_FORMAT "k).",
1476                  p2i(brk_now), (size_t)((brk_now - g_brk_at_startup) / K));
1477   }
1478   st->print_cr("MaxExpectedDataSegmentSize    : " SIZE_FORMAT "k.", MaxExpectedDataSegmentSize / K);
1479   st->cr();
1480 
1481   // Print segments allocated with os::reserve_memory.
1482   st->print_cr("internal virtual memory regions used by vm:");
1483   vmembk_print_on(st);
1484 }
1485 
1486 // Get a string for the cpuinfo that is a summary of the cpu type
1487 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1488   // read _system_configuration.version
1489   switch (_system_configuration.version) {
1490   case PV_9:
1491     strncpy(buf, "Power PC 9", buflen);
1492     break;
1493   case PV_8:
1494     strncpy(buf, "Power PC 8", buflen);
1495     break;
1496   case PV_7:
1497     strncpy(buf, "Power PC 7", buflen);
1498     break;
1499   case PV_6_1:
1500     strncpy(buf, "Power PC 6 DD1.x", buflen);
1501     break;
1502   case PV_6:
1503     strncpy(buf, "Power PC 6", buflen);
1504     break;
1505   case PV_5:
1506     strncpy(buf, "Power PC 5", buflen);
1507     break;
1508   case PV_5_2:
1509     strncpy(buf, "Power PC 5_2", buflen);
1510     break;
1511   case PV_5_3:
1512     strncpy(buf, "Power PC 5_3", buflen);
1513     break;
1514   case PV_5_Compat:
1515     strncpy(buf, "PV_5_Compat", buflen);
1516     break;
1517   case PV_6_Compat:
1518     strncpy(buf, "PV_6_Compat", buflen);
1519     break;
1520   case PV_7_Compat:
1521     strncpy(buf, "PV_7_Compat", buflen);
1522     break;
1523   case PV_8_Compat:
1524     strncpy(buf, "PV_8_Compat", buflen);
1525     break;
1526   case PV_9_Compat:
1527     strncpy(buf, "PV_9_Compat", buflen);
1528     break;
1529   default:
1530     strncpy(buf, "unknown", buflen);
1531   }
1532 }
1533 
1534 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1535   // Nothing to do beyond of what os::print_cpu_info() does.
1536 }
1537 
1538 static void print_signal_handler(outputStream* st, int sig,
1539                                  char* buf, size_t buflen);
1540 
1541 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1542   st->print_cr("Signal Handlers:");
1543   print_signal_handler(st, SIGSEGV, buf, buflen);
1544   print_signal_handler(st, SIGBUS , buf, buflen);
1545   print_signal_handler(st, SIGFPE , buf, buflen);
1546   print_signal_handler(st, SIGPIPE, buf, buflen);
1547   print_signal_handler(st, SIGXFSZ, buf, buflen);
1548   print_signal_handler(st, SIGILL , buf, buflen);
1549   print_signal_handler(st, SR_signum, buf, buflen);
1550   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1551   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1552   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1553   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1554   print_signal_handler(st, SIGTRAP, buf, buflen);
1555   // We also want to know if someone else adds a SIGDANGER handler because
1556   // that will interfere with OOM killling.
1557   print_signal_handler(st, SIGDANGER, buf, buflen);
1558 }
1559 
1560 static char saved_jvm_path[MAXPATHLEN] = {0};
1561 
1562 // Find the full path to the current module, libjvm.so.
1563 void os::jvm_path(char *buf, jint buflen) {
1564   // Error checking.
1565   if (buflen < MAXPATHLEN) {
1566     assert(false, "must use a large-enough buffer");
1567     buf[0] = '\0';
1568     return;
1569   }
1570   // Lazy resolve the path to current module.
1571   if (saved_jvm_path[0] != 0) {
1572     strcpy(buf, saved_jvm_path);
1573     return;
1574   }
1575 
1576   Dl_info dlinfo;
1577   int ret = dladdr(CAST_FROM_FN_PTR(void *, os::jvm_path), &dlinfo);
1578   assert(ret != 0, "cannot locate libjvm");
1579   char* rp = os::Posix::realpath((char *)dlinfo.dli_fname, buf, buflen);
1580   assert(rp != NULL, "error in realpath(): maybe the 'path' argument is too long?");
1581 
1582   if (Arguments::sun_java_launcher_is_altjvm()) {
1583     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1584     // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
1585     // If "/jre/lib/" appears at the right place in the string, then
1586     // assume we are installed in a JDK and we're done. Otherwise, check
1587     // for a JAVA_HOME environment variable and fix up the path so it
1588     // looks like libjvm.so is installed there (append a fake suffix
1589     // hotspot/libjvm.so).
1590     const char *p = buf + strlen(buf) - 1;
1591     for (int count = 0; p > buf && count < 4; ++count) {
1592       for (--p; p > buf && *p != '/'; --p)
1593         /* empty */ ;
1594     }
1595 
1596     if (strncmp(p, "/jre/lib/", 9) != 0) {
1597       // Look for JAVA_HOME in the environment.
1598       char* java_home_var = ::getenv("JAVA_HOME");
1599       if (java_home_var != NULL && java_home_var[0] != 0) {
1600         char* jrelib_p;
1601         int len;
1602 
1603         // Check the current module name "libjvm.so".
1604         p = strrchr(buf, '/');
1605         if (p == NULL) {
1606           return;
1607         }
1608         assert(strstr(p, "/libjvm") == p, "invalid library name");
1609 
1610         rp = os::Posix::realpath(java_home_var, buf, buflen);
1611         if (rp == NULL) {
1612           return;
1613         }
1614 
1615         // determine if this is a legacy image or modules image
1616         // modules image doesn't have "jre" subdirectory
1617         len = strlen(buf);
1618         assert(len < buflen, "Ran out of buffer room");
1619         jrelib_p = buf + len;
1620         snprintf(jrelib_p, buflen-len, "/jre/lib");
1621         if (0 != access(buf, F_OK)) {
1622           snprintf(jrelib_p, buflen-len, "/lib");
1623         }
1624 
1625         if (0 == access(buf, F_OK)) {
1626           // Use current module name "libjvm.so"
1627           len = strlen(buf);
1628           snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
1629         } else {
1630           // Go back to path of .so
1631           rp = os::Posix::realpath((char *)dlinfo.dli_fname, buf, buflen);
1632           if (rp == NULL) {
1633             return;
1634           }
1635         }
1636       }
1637     }
1638   }
1639 
1640   strncpy(saved_jvm_path, buf, sizeof(saved_jvm_path));
1641   saved_jvm_path[sizeof(saved_jvm_path) - 1] = '\0';
1642 }
1643 
1644 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1645   // no prefix required, not even "_"
1646 }
1647 
1648 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1649   // no suffix required
1650 }
1651 
1652 ////////////////////////////////////////////////////////////////////////////////
1653 // sun.misc.Signal support
1654 
1655 static void
1656 UserHandler(int sig, void *siginfo, void *context) {
1657   // Ctrl-C is pressed during error reporting, likely because the error
1658   // handler fails to abort. Let VM die immediately.
1659   if (sig == SIGINT && VMError::is_error_reported()) {
1660     os::die();
1661   }
1662 
1663   os::signal_notify(sig);
1664 }
1665 
1666 void* os::user_handler() {
1667   return CAST_FROM_FN_PTR(void*, UserHandler);
1668 }
1669 
1670 extern "C" {
1671   typedef void (*sa_handler_t)(int);
1672   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1673 }
1674 
1675 void* os::signal(int signal_number, void* handler) {
1676   struct sigaction sigAct, oldSigAct;
1677 
1678   sigfillset(&(sigAct.sa_mask));
1679 
1680   // Do not block out synchronous signals in the signal handler.
1681   // Blocking synchronous signals only makes sense if you can really
1682   // be sure that those signals won't happen during signal handling,
1683   // when the blocking applies. Normal signal handlers are lean and
1684   // do not cause signals. But our signal handlers tend to be "risky"
1685   // - secondary SIGSEGV, SIGILL, SIGBUS' may and do happen.
1686   // On AIX, PASE there was a case where a SIGSEGV happened, followed
1687   // by a SIGILL, which was blocked due to the signal mask. The process
1688   // just hung forever. Better to crash from a secondary signal than to hang.
1689   sigdelset(&(sigAct.sa_mask), SIGSEGV);
1690   sigdelset(&(sigAct.sa_mask), SIGBUS);
1691   sigdelset(&(sigAct.sa_mask), SIGILL);
1692   sigdelset(&(sigAct.sa_mask), SIGFPE);
1693   sigdelset(&(sigAct.sa_mask), SIGTRAP);
1694 
1695   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1696 
1697   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1698 
1699   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1700     // -1 means registration failed
1701     return (void *)-1;
1702   }
1703 
1704   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1705 }
1706 
1707 void os::signal_raise(int signal_number) {
1708   ::raise(signal_number);
1709 }
1710 
1711 //
1712 // The following code is moved from os.cpp for making this
1713 // code platform specific, which it is by its very nature.
1714 //
1715 
1716 // Will be modified when max signal is changed to be dynamic
1717 int os::sigexitnum_pd() {
1718   return NSIG;
1719 }
1720 
1721 // a counter for each possible signal value
1722 static volatile jint pending_signals[NSIG+1] = { 0 };
1723 
1724 // Wrapper functions for: sem_init(), sem_post(), sem_wait()
1725 // On AIX, we use sem_init(), sem_post(), sem_wait()
1726 // On Pase, we need to use msem_lock() and msem_unlock(), because Posix Semaphores
1727 // do not seem to work at all on PASE (unimplemented, will cause SIGILL).
1728 // Note that just using msem_.. APIs for both PASE and AIX is not an option either, as
1729 // on AIX, msem_..() calls are suspected of causing problems.
1730 static sem_t sig_sem;
1731 static msemaphore* p_sig_msem = 0;
1732 
1733 static void local_sem_init() {
1734   if (os::Aix::on_aix()) {
1735     int rc = ::sem_init(&sig_sem, 0, 0);
1736     guarantee(rc != -1, "sem_init failed");
1737   } else {
1738     // Memory semaphores must live in shared mem.
1739     guarantee0(p_sig_msem == NULL);
1740     p_sig_msem = (msemaphore*)os::reserve_memory(sizeof(msemaphore), NULL);
1741     guarantee(p_sig_msem, "Cannot allocate memory for memory semaphore");
1742     guarantee(::msem_init(p_sig_msem, 0) == p_sig_msem, "msem_init failed");
1743   }
1744 }
1745 
1746 static void local_sem_post() {
1747   static bool warn_only_once = false;
1748   if (os::Aix::on_aix()) {
1749     int rc = ::sem_post(&sig_sem);
1750     if (rc == -1 && !warn_only_once) {
1751       trcVerbose("sem_post failed (errno = %d, %s)", errno, os::errno_name(errno));
1752       warn_only_once = true;
1753     }
1754   } else {
1755     guarantee0(p_sig_msem != NULL);
1756     int rc = ::msem_unlock(p_sig_msem, 0);
1757     if (rc == -1 && !warn_only_once) {
1758       trcVerbose("msem_unlock failed (errno = %d, %s)", errno, os::errno_name(errno));
1759       warn_only_once = true;
1760     }
1761   }
1762 }
1763 
1764 static void local_sem_wait() {
1765   static bool warn_only_once = false;
1766   if (os::Aix::on_aix()) {
1767     int rc = ::sem_wait(&sig_sem);
1768     if (rc == -1 && !warn_only_once) {
1769       trcVerbose("sem_wait failed (errno = %d, %s)", errno, os::errno_name(errno));
1770       warn_only_once = true;
1771     }
1772   } else {
1773     guarantee0(p_sig_msem != NULL); // must init before use
1774     int rc = ::msem_lock(p_sig_msem, 0);
1775     if (rc == -1 && !warn_only_once) {
1776       trcVerbose("msem_lock failed (errno = %d, %s)", errno, os::errno_name(errno));
1777       warn_only_once = true;
1778     }
1779   }
1780 }
1781 
1782 static void jdk_misc_signal_init() {
1783   // Initialize signal structures
1784   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1785 
1786   // Initialize signal semaphore
1787   local_sem_init();
1788 }
1789 
1790 void os::signal_notify(int sig) {
1791   Atomic::inc(&pending_signals[sig]);
1792   local_sem_post();
1793 }
1794 
1795 static int check_pending_signals() {
1796   for (;;) {
1797     for (int i = 0; i < NSIG + 1; i++) {
1798       jint n = pending_signals[i];
1799       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1800         return i;
1801       }
1802     }
1803     JavaThread *thread = JavaThread::current();
1804     ThreadBlockInVM tbivm(thread);
1805 
1806     bool threadIsSuspended;
1807     do {
1808       thread->set_suspend_equivalent();
1809       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1810 
1811       local_sem_wait();
1812 
1813       // were we externally suspended while we were waiting?
1814       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1815       if (threadIsSuspended) {
1816         //
1817         // The semaphore has been incremented, but while we were waiting
1818         // another thread suspended us. We don't want to continue running
1819         // while suspended because that would surprise the thread that
1820         // suspended us.
1821         //
1822 
1823         local_sem_post();
1824 
1825         thread->java_suspend_self();
1826       }
1827     } while (threadIsSuspended);
1828   }
1829 }
1830 
1831 int os::signal_wait() {
1832   return check_pending_signals();
1833 }
1834 
1835 ////////////////////////////////////////////////////////////////////////////////
1836 // Virtual Memory
1837 
1838 // We need to keep small simple bookkeeping for os::reserve_memory and friends.
1839 
1840 #define VMEM_MAPPED  1
1841 #define VMEM_SHMATED 2
1842 
1843 struct vmembk_t {
1844   int type;         // 1 - mmap, 2 - shmat
1845   char* addr;
1846   size_t size;      // Real size, may be larger than usersize.
1847   size_t pagesize;  // page size of area
1848   vmembk_t* next;
1849 
1850   bool contains_addr(char* p) const {
1851     return p >= addr && p < (addr + size);
1852   }
1853 
1854   bool contains_range(char* p, size_t s) const {
1855     return contains_addr(p) && contains_addr(p + s - 1);
1856   }
1857 
1858   void print_on(outputStream* os) const {
1859     os->print("[" PTR_FORMAT " - " PTR_FORMAT "] (" UINTX_FORMAT
1860       " bytes, %d %s pages), %s",
1861       addr, addr + size - 1, size, size / pagesize, describe_pagesize(pagesize),
1862       (type == VMEM_SHMATED ? "shmat" : "mmap")
1863     );
1864   }
1865 
1866   // Check that range is a sub range of memory block (or equal to memory block);
1867   // also check that range is fully page aligned to the page size if the block.
1868   void assert_is_valid_subrange(char* p, size_t s) const {
1869     if (!contains_range(p, s)) {
1870       trcVerbose("[" PTR_FORMAT " - " PTR_FORMAT "] is not a sub "
1871               "range of [" PTR_FORMAT " - " PTR_FORMAT "].",
1872               p2i(p), p2i(p + s), p2i(addr), p2i(addr + size));
1873       guarantee0(false);
1874     }
1875     if (!is_aligned_to(p, pagesize) || !is_aligned_to(p + s, pagesize)) {
1876       trcVerbose("range [" PTR_FORMAT " - " PTR_FORMAT "] is not"
1877               " aligned to pagesize (%lu)", p2i(p), p2i(p + s), (unsigned long) pagesize);
1878       guarantee0(false);
1879     }
1880   }
1881 };
1882 
1883 static struct {
1884   vmembk_t* first;
1885   MiscUtils::CritSect cs;
1886 } vmem;
1887 
1888 static void vmembk_add(char* addr, size_t size, size_t pagesize, int type) {
1889   vmembk_t* p = (vmembk_t*) ::malloc(sizeof(vmembk_t));
1890   assert0(p);
1891   if (p) {
1892     MiscUtils::AutoCritSect lck(&vmem.cs);
1893     p->addr = addr; p->size = size;
1894     p->pagesize = pagesize;
1895     p->type = type;
1896     p->next = vmem.first;
1897     vmem.first = p;
1898   }
1899 }
1900 
1901 static vmembk_t* vmembk_find(char* addr) {
1902   MiscUtils::AutoCritSect lck(&vmem.cs);
1903   for (vmembk_t* p = vmem.first; p; p = p->next) {
1904     if (p->addr <= addr && (p->addr + p->size) > addr) {
1905       return p;
1906     }
1907   }
1908   return NULL;
1909 }
1910 
1911 static void vmembk_remove(vmembk_t* p0) {
1912   MiscUtils::AutoCritSect lck(&vmem.cs);
1913   assert0(p0);
1914   assert0(vmem.first); // List should not be empty.
1915   for (vmembk_t** pp = &(vmem.first); *pp; pp = &((*pp)->next)) {
1916     if (*pp == p0) {
1917       *pp = p0->next;
1918       ::free(p0);
1919       return;
1920     }
1921   }
1922   assert0(false); // Not found?
1923 }
1924 
1925 static void vmembk_print_on(outputStream* os) {
1926   MiscUtils::AutoCritSect lck(&vmem.cs);
1927   for (vmembk_t* vmi = vmem.first; vmi; vmi = vmi->next) {
1928     vmi->print_on(os);
1929     os->cr();
1930   }
1931 }
1932 
1933 // Reserve and attach a section of System V memory.
1934 // If <requested_addr> is not NULL, function will attempt to attach the memory at the given
1935 // address. Failing that, it will attach the memory anywhere.
1936 // If <requested_addr> is NULL, function will attach the memory anywhere.
1937 //
1938 // <alignment_hint> is being ignored by this function. It is very probable however that the
1939 // alignment requirements are met anyway, because shmat() attaches at 256M boundaries.
1940 // Should this be not enogh, we can put more work into it.
1941 static char* reserve_shmated_memory (
1942   size_t bytes,
1943   char* requested_addr,
1944   size_t alignment_hint) {
1945 
1946   trcVerbose("reserve_shmated_memory " UINTX_FORMAT " bytes, wishaddress "
1947     PTR_FORMAT ", alignment_hint " UINTX_FORMAT "...",
1948     bytes, p2i(requested_addr), alignment_hint);
1949 
1950   // Either give me wish address or wish alignment but not both.
1951   assert0(!(requested_addr != NULL && alignment_hint != 0));
1952 
1953   // We must prevent anyone from attaching too close to the
1954   // BRK because that may cause malloc OOM.
1955   if (requested_addr != NULL && is_close_to_brk((address)requested_addr)) {
1956     trcVerbose("Wish address " PTR_FORMAT " is too close to the BRK segment. "
1957       "Will attach anywhere.", p2i(requested_addr));
1958     // Act like the OS refused to attach there.
1959     requested_addr = NULL;
1960   }
1961 
1962   // For old AS/400's (V5R4 and older) we should not even be here - System V shared memory is not
1963   // really supported (max size 4GB), so reserve_mmapped_memory should have been used instead.
1964   if (os::Aix::on_pase_V5R4_or_older()) {
1965     ShouldNotReachHere();
1966   }
1967 
1968   // Align size of shm up to 64K to avoid errors if we later try to change the page size.
1969   const size_t size = align_up(bytes, 64*K);
1970 
1971   // Reserve the shared segment.
1972   int shmid = shmget(IPC_PRIVATE, size, IPC_CREAT | S_IRUSR | S_IWUSR);
1973   if (shmid == -1) {
1974     trcVerbose("shmget(.., " UINTX_FORMAT ", ..) failed (errno: %d).", size, errno);
1975     return NULL;
1976   }
1977 
1978   // Important note:
1979   // It is very important that we, upon leaving this function, do not leave a shm segment alive.
1980   // We must right after attaching it remove it from the system. System V shm segments are global and
1981   // survive the process.
1982   // So, from here on: Do not assert, do not return, until we have called shmctl(IPC_RMID) (A).
1983 
1984   struct shmid_ds shmbuf;
1985   memset(&shmbuf, 0, sizeof(shmbuf));
1986   shmbuf.shm_pagesize = 64*K;
1987   if (shmctl(shmid, SHM_PAGESIZE, &shmbuf) != 0) {
1988     trcVerbose("Failed to set page size (need " UINTX_FORMAT " 64K pages) - shmctl failed with %d.",
1989                size / (64*K), errno);
1990     // I want to know if this ever happens.
1991     assert(false, "failed to set page size for shmat");
1992   }
1993 
1994   // Now attach the shared segment.
1995   // Note that I attach with SHM_RND - which means that the requested address is rounded down, if
1996   // needed, to the next lowest segment boundary. Otherwise the attach would fail if the address
1997   // were not a segment boundary.
1998   char* const addr = (char*) shmat(shmid, requested_addr, SHM_RND);
1999   const int errno_shmat = errno;
2000 
2001   // (A) Right after shmat and before handing shmat errors delete the shm segment.
2002   if (::shmctl(shmid, IPC_RMID, NULL) == -1) {
2003     trcVerbose("shmctl(%u, IPC_RMID) failed (%d)\n", shmid, errno);
2004     assert(false, "failed to remove shared memory segment!");
2005   }
2006 
2007   // Handle shmat error. If we failed to attach, just return.
2008   if (addr == (char*)-1) {
2009     trcVerbose("Failed to attach segment at " PTR_FORMAT " (%d).", p2i(requested_addr), errno_shmat);
2010     return NULL;
2011   }
2012 
2013   // Just for info: query the real page size. In case setting the page size did not
2014   // work (see above), the system may have given us something other then 4K (LDR_CNTRL).
2015   const size_t real_pagesize = os::Aix::query_pagesize(addr);
2016   if (real_pagesize != shmbuf.shm_pagesize) {
2017     trcVerbose("pagesize is, surprisingly, " SIZE_FORMAT, real_pagesize);
2018   }
2019 
2020   if (addr) {
2021     trcVerbose("shm-allocated " PTR_FORMAT " .. " PTR_FORMAT " (" UINTX_FORMAT " bytes, " UINTX_FORMAT " %s pages)",
2022       p2i(addr), p2i(addr + size - 1), size, size/real_pagesize, describe_pagesize(real_pagesize));
2023   } else {
2024     if (requested_addr != NULL) {
2025       trcVerbose("failed to shm-allocate " UINTX_FORMAT " bytes at with address " PTR_FORMAT ".", size, p2i(requested_addr));
2026     } else {
2027       trcVerbose("failed to shm-allocate " UINTX_FORMAT " bytes at any address.", size);
2028     }
2029   }
2030 
2031   // book-keeping
2032   vmembk_add(addr, size, real_pagesize, VMEM_SHMATED);
2033   assert0(is_aligned_to(addr, os::vm_page_size()));
2034 
2035   return addr;
2036 }
2037 
2038 static bool release_shmated_memory(char* addr, size_t size) {
2039 
2040   trcVerbose("release_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2041     p2i(addr), p2i(addr + size - 1));
2042 
2043   bool rc = false;
2044 
2045   // TODO: is there a way to verify shm size without doing bookkeeping?
2046   if (::shmdt(addr) != 0) {
2047     trcVerbose("error (%d).", errno);
2048   } else {
2049     trcVerbose("ok.");
2050     rc = true;
2051   }
2052   return rc;
2053 }
2054 
2055 static bool uncommit_shmated_memory(char* addr, size_t size) {
2056   trcVerbose("uncommit_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2057     p2i(addr), p2i(addr + size - 1));
2058 
2059   const bool rc = my_disclaim64(addr, size);
2060 
2061   if (!rc) {
2062     trcVerbose("my_disclaim64(" PTR_FORMAT ", " UINTX_FORMAT ") failed.\n", p2i(addr), size);
2063     return false;
2064   }
2065   return true;
2066 }
2067 
2068 ////////////////////////////////  mmap-based routines /////////////////////////////////
2069 
2070 // Reserve memory via mmap.
2071 // If <requested_addr> is given, an attempt is made to attach at the given address.
2072 // Failing that, memory is allocated at any address.
2073 // If <alignment_hint> is given and <requested_addr> is NULL, an attempt is made to
2074 // allocate at an address aligned with the given alignment. Failing that, memory
2075 // is aligned anywhere.
2076 static char* reserve_mmaped_memory(size_t bytes, char* requested_addr, size_t alignment_hint) {
2077   trcVerbose("reserve_mmaped_memory " UINTX_FORMAT " bytes, wishaddress " PTR_FORMAT ", "
2078     "alignment_hint " UINTX_FORMAT "...",
2079     bytes, p2i(requested_addr), alignment_hint);
2080 
2081   // If a wish address is given, but not aligned to 4K page boundary, mmap will fail.
2082   if (requested_addr && !is_aligned_to(requested_addr, os::vm_page_size()) != 0) {
2083     trcVerbose("Wish address " PTR_FORMAT " not aligned to page boundary.", p2i(requested_addr));
2084     return NULL;
2085   }
2086 
2087   // We must prevent anyone from attaching too close to the
2088   // BRK because that may cause malloc OOM.
2089   if (requested_addr != NULL && is_close_to_brk((address)requested_addr)) {
2090     trcVerbose("Wish address " PTR_FORMAT " is too close to the BRK segment. "
2091       "Will attach anywhere.", p2i(requested_addr));
2092     // Act like the OS refused to attach there.
2093     requested_addr = NULL;
2094   }
2095 
2096   // Specify one or the other but not both.
2097   assert0(!(requested_addr != NULL && alignment_hint > 0));
2098 
2099   // In 64K mode, we claim the global page size (os::vm_page_size())
2100   // is 64K. This is one of the few points where that illusion may
2101   // break, because mmap() will always return memory aligned to 4K. So
2102   // we must ensure we only ever return memory aligned to 64k.
2103   if (alignment_hint) {
2104     alignment_hint = lcm(alignment_hint, os::vm_page_size());
2105   } else {
2106     alignment_hint = os::vm_page_size();
2107   }
2108 
2109   // Size shall always be a multiple of os::vm_page_size (esp. in 64K mode).
2110   const size_t size = align_up(bytes, os::vm_page_size());
2111 
2112   // alignment: Allocate memory large enough to include an aligned range of the right size and
2113   // cut off the leading and trailing waste pages.
2114   assert0(alignment_hint != 0 && is_aligned_to(alignment_hint, os::vm_page_size())); // see above
2115   const size_t extra_size = size + alignment_hint;
2116 
2117   // Note: MAP_SHARED (instead of MAP_PRIVATE) needed to be able to
2118   // later use msync(MS_INVALIDATE) (see os::uncommit_memory).
2119   int flags = MAP_ANONYMOUS | MAP_SHARED;
2120 
2121   // MAP_FIXED is needed to enforce requested_addr - manpage is vague about what
2122   // it means if wishaddress is given but MAP_FIXED is not set.
2123   //
2124   // Important! Behaviour differs depending on whether SPEC1170 mode is active or not.
2125   // SPEC1170 mode active: behaviour like POSIX, MAP_FIXED will clobber existing mappings.
2126   // SPEC1170 mode not active: behaviour, unlike POSIX, is that no existing mappings will
2127   // get clobbered.
2128   if (requested_addr != NULL) {
2129     if (!os::Aix::xpg_sus_mode()) {  // not SPEC1170 Behaviour
2130       flags |= MAP_FIXED;
2131     }
2132   }
2133 
2134   char* addr = (char*)::mmap(requested_addr, extra_size,
2135       PROT_READ|PROT_WRITE|PROT_EXEC, flags, -1, 0);
2136 
2137   if (addr == MAP_FAILED) {
2138     trcVerbose("mmap(" PTR_FORMAT ", " UINTX_FORMAT ", ..) failed (%d)", p2i(requested_addr), size, errno);
2139     return NULL;
2140   }
2141 
2142   // Handle alignment.
2143   char* const addr_aligned = align_up(addr, alignment_hint);
2144   const size_t waste_pre = addr_aligned - addr;
2145   char* const addr_aligned_end = addr_aligned + size;
2146   const size_t waste_post = extra_size - waste_pre - size;
2147   if (waste_pre > 0) {
2148     ::munmap(addr, waste_pre);
2149   }
2150   if (waste_post > 0) {
2151     ::munmap(addr_aligned_end, waste_post);
2152   }
2153   addr = addr_aligned;
2154 
2155   if (addr) {
2156     trcVerbose("mmap-allocated " PTR_FORMAT " .. " PTR_FORMAT " (" UINTX_FORMAT " bytes)",
2157       p2i(addr), p2i(addr + bytes), bytes);
2158   } else {
2159     if (requested_addr != NULL) {
2160       trcVerbose("failed to mmap-allocate " UINTX_FORMAT " bytes at wish address " PTR_FORMAT ".", bytes, p2i(requested_addr));
2161     } else {
2162       trcVerbose("failed to mmap-allocate " UINTX_FORMAT " bytes at any address.", bytes);
2163     }
2164   }
2165 
2166   // bookkeeping
2167   vmembk_add(addr, size, 4*K, VMEM_MAPPED);
2168 
2169   // Test alignment, see above.
2170   assert0(is_aligned_to(addr, os::vm_page_size()));
2171 
2172   return addr;
2173 }
2174 
2175 static bool release_mmaped_memory(char* addr, size_t size) {
2176   assert0(is_aligned_to(addr, os::vm_page_size()));
2177   assert0(is_aligned_to(size, os::vm_page_size()));
2178 
2179   trcVerbose("release_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2180     p2i(addr), p2i(addr + size - 1));
2181   bool rc = false;
2182 
2183   if (::munmap(addr, size) != 0) {
2184     trcVerbose("failed (%d)\n", errno);
2185     rc = false;
2186   } else {
2187     trcVerbose("ok.");
2188     rc = true;
2189   }
2190 
2191   return rc;
2192 }
2193 
2194 static bool uncommit_mmaped_memory(char* addr, size_t size) {
2195 
2196   assert0(is_aligned_to(addr, os::vm_page_size()));
2197   assert0(is_aligned_to(size, os::vm_page_size()));
2198 
2199   trcVerbose("uncommit_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2200     p2i(addr), p2i(addr + size - 1));
2201   bool rc = false;
2202 
2203   // Uncommit mmap memory with msync MS_INVALIDATE.
2204   if (::msync(addr, size, MS_INVALIDATE) != 0) {
2205     trcVerbose("failed (%d)\n", errno);
2206     rc = false;
2207   } else {
2208     trcVerbose("ok.");
2209     rc = true;
2210   }
2211 
2212   return rc;
2213 }
2214 
2215 int os::vm_page_size() {
2216   // Seems redundant as all get out.
2217   assert(os::Aix::page_size() != -1, "must call os::init");
2218   return os::Aix::page_size();
2219 }
2220 
2221 // Aix allocates memory by pages.
2222 int os::vm_allocation_granularity() {
2223   assert(os::Aix::page_size() != -1, "must call os::init");
2224   return os::Aix::page_size();
2225 }
2226 
2227 #ifdef PRODUCT
2228 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2229                                     int err) {
2230   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2231           ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
2232           os::errno_name(err), err);
2233 }
2234 #endif
2235 
2236 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2237                                   const char* mesg) {
2238   assert(mesg != NULL, "mesg must be specified");
2239   if (!pd_commit_memory(addr, size, exec)) {
2240     // Add extra info in product mode for vm_exit_out_of_memory():
2241     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2242     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2243   }
2244 }
2245 
2246 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2247 
2248   assert(is_aligned_to(addr, os::vm_page_size()),
2249     "addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2250     p2i(addr), os::vm_page_size());
2251   assert(is_aligned_to(size, os::vm_page_size()),
2252     "size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2253     size, os::vm_page_size());
2254 
2255   vmembk_t* const vmi = vmembk_find(addr);
2256   guarantee0(vmi);
2257   vmi->assert_is_valid_subrange(addr, size);
2258 
2259   trcVerbose("commit_memory [" PTR_FORMAT " - " PTR_FORMAT "].", p2i(addr), p2i(addr + size - 1));
2260 
2261   if (UseExplicitCommit) {
2262     // AIX commits memory on touch. So, touch all pages to be committed.
2263     for (char* p = addr; p < (addr + size); p += 4*K) {
2264       *p = '\0';
2265     }
2266   }
2267 
2268   return true;
2269 }
2270 
2271 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, bool exec) {
2272   return pd_commit_memory(addr, size, exec);
2273 }
2274 
2275 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2276                                   size_t alignment_hint, bool exec,
2277                                   const char* mesg) {
2278   // Alignment_hint is ignored on this OS.
2279   pd_commit_memory_or_exit(addr, size, exec, mesg);
2280 }
2281 
2282 bool os::pd_uncommit_memory(char* addr, size_t size) {
2283   assert(is_aligned_to(addr, os::vm_page_size()),
2284     "addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2285     p2i(addr), os::vm_page_size());
2286   assert(is_aligned_to(size, os::vm_page_size()),
2287     "size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2288     size, os::vm_page_size());
2289 
2290   // Dynamically do different things for mmap/shmat.
2291   const vmembk_t* const vmi = vmembk_find(addr);
2292   guarantee0(vmi);
2293   vmi->assert_is_valid_subrange(addr, size);
2294 
2295   if (vmi->type == VMEM_SHMATED) {
2296     return uncommit_shmated_memory(addr, size);
2297   } else {
2298     return uncommit_mmaped_memory(addr, size);
2299   }
2300 }
2301 
2302 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2303   // Do not call this; no need to commit stack pages on AIX.
2304   ShouldNotReachHere();
2305   return true;
2306 }
2307 
2308 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2309   // Do not call this; no need to commit stack pages on AIX.
2310   ShouldNotReachHere();
2311   return true;
2312 }
2313 
2314 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2315 }
2316 
2317 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2318 }
2319 
2320 void os::numa_make_global(char *addr, size_t bytes) {
2321 }
2322 
2323 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2324 }
2325 
2326 bool os::numa_topology_changed() {
2327   return false;
2328 }
2329 
2330 size_t os::numa_get_groups_num() {
2331   return 1;
2332 }
2333 
2334 int os::numa_get_group_id() {
2335   return 0;
2336 }
2337 
2338 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2339   if (size > 0) {
2340     ids[0] = 0;
2341     return 1;
2342   }
2343   return 0;
2344 }
2345 
2346 int os::numa_get_group_id_for_address(const void* address) {
2347   return 0;
2348 }
2349 
2350 bool os::get_page_info(char *start, page_info* info) {
2351   return false;
2352 }
2353 
2354 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2355   return end;
2356 }
2357 
2358 // Reserves and attaches a shared memory segment.
2359 // Will assert if a wish address is given and could not be obtained.
2360 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, size_t alignment_hint) {
2361 
2362   // All other Unices do a mmap(MAP_FIXED) if the addr is given,
2363   // thereby clobbering old mappings at that place. That is probably
2364   // not intended, never used and almost certainly an error were it
2365   // ever be used this way (to try attaching at a specified address
2366   // without clobbering old mappings an alternate API exists,
2367   // os::attempt_reserve_memory_at()).
2368   // Instead of mimicking the dangerous coding of the other platforms, here I
2369   // just ignore the request address (release) or assert(debug).
2370   assert0(requested_addr == NULL);
2371 
2372   // Always round to os::vm_page_size(), which may be larger than 4K.
2373   bytes = align_up(bytes, os::vm_page_size());
2374   const size_t alignment_hint0 =
2375     alignment_hint ? align_up(alignment_hint, os::vm_page_size()) : 0;
2376 
2377   // In 4K mode always use mmap.
2378   // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2379   if (os::vm_page_size() == 4*K) {
2380     return reserve_mmaped_memory(bytes, requested_addr, alignment_hint);
2381   } else {
2382     if (bytes >= Use64KPagesThreshold) {
2383       return reserve_shmated_memory(bytes, requested_addr, alignment_hint);
2384     } else {
2385       return reserve_mmaped_memory(bytes, requested_addr, alignment_hint);
2386     }
2387   }
2388 }
2389 
2390 bool os::pd_release_memory(char* addr, size_t size) {
2391 
2392   // Dynamically do different things for mmap/shmat.
2393   vmembk_t* const vmi = vmembk_find(addr);
2394   guarantee0(vmi);
2395 
2396   // Always round to os::vm_page_size(), which may be larger than 4K.
2397   size = align_up(size, os::vm_page_size());
2398   addr = align_up(addr, os::vm_page_size());
2399 
2400   bool rc = false;
2401   bool remove_bookkeeping = false;
2402   if (vmi->type == VMEM_SHMATED) {
2403     // For shmatted memory, we do:
2404     // - If user wants to release the whole range, release the memory (shmdt).
2405     // - If user only wants to release a partial range, uncommit (disclaim) that
2406     //   range. That way, at least, we do not use memory anymore (bust still page
2407     //   table space).
2408     vmi->assert_is_valid_subrange(addr, size);
2409     if (addr == vmi->addr && size == vmi->size) {
2410       rc = release_shmated_memory(addr, size);
2411       remove_bookkeeping = true;
2412     } else {
2413       rc = uncommit_shmated_memory(addr, size);
2414     }
2415   } else {
2416     // User may unmap partial regions but region has to be fully contained.
2417 #ifdef ASSERT
2418     vmi->assert_is_valid_subrange(addr, size);
2419 #endif
2420     rc = release_mmaped_memory(addr, size);
2421     remove_bookkeeping = true;
2422   }
2423 
2424   // update bookkeeping
2425   if (rc && remove_bookkeeping) {
2426     vmembk_remove(vmi);
2427   }
2428 
2429   return rc;
2430 }
2431 
2432 static bool checked_mprotect(char* addr, size_t size, int prot) {
2433 
2434   // Little problem here: if SPEC1170 behaviour is off, mprotect() on AIX will
2435   // not tell me if protection failed when trying to protect an un-protectable range.
2436   //
2437   // This means if the memory was allocated using shmget/shmat, protection wont work
2438   // but mprotect will still return 0:
2439   //
2440   // See http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.basetechref/doc/basetrf1/mprotect.htm
2441 
2442   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
2443   bool rc = ::mprotect(addr, size, prot) == 0 ? true : false;
2444 
2445   if (!rc) {
2446     const char* const s_errno = os::errno_name(errno);
2447     warning("mprotect(" PTR_FORMAT "-" PTR_FORMAT ", 0x%X) failed (%s).", addr, addr + size, prot, s_errno);
2448     return false;
2449   }
2450 
2451   // mprotect success check
2452   //
2453   // Mprotect said it changed the protection but can I believe it?
2454   //
2455   // To be sure I need to check the protection afterwards. Try to
2456   // read from protected memory and check whether that causes a segfault.
2457   //
2458   if (!os::Aix::xpg_sus_mode()) {
2459 
2460     if (CanUseSafeFetch32()) {
2461 
2462       const bool read_protected =
2463         (SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
2464          SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
2465 
2466       if (prot & PROT_READ) {
2467         rc = !read_protected;
2468       } else {
2469         rc = read_protected;
2470       }
2471 
2472       if (!rc) {
2473         if (os::Aix::on_pase()) {
2474           // There is an issue on older PASE systems where mprotect() will return success but the
2475           // memory will not be protected.
2476           // This has nothing to do with the problem of using mproect() on SPEC1170 incompatible
2477           // machines; we only see it rarely, when using mprotect() to protect the guard page of
2478           // a stack. It is an OS error.
2479           //
2480           // A valid strategy is just to try again. This usually works. :-/
2481 
2482           ::usleep(1000);
2483           Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
2484           if (::mprotect(addr, size, prot) == 0) {
2485             const bool read_protected_2 =
2486               (SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
2487               SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
2488             rc = true;
2489           }
2490         }
2491       }
2492     }
2493   }
2494 
2495   assert(rc == true, "mprotect failed.");
2496 
2497   return rc;
2498 }
2499 
2500 // Set protections specified
2501 bool os::protect_memory(char* addr, size_t size, ProtType prot, bool is_committed) {
2502   unsigned int p = 0;
2503   switch (prot) {
2504   case MEM_PROT_NONE: p = PROT_NONE; break;
2505   case MEM_PROT_READ: p = PROT_READ; break;
2506   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2507   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2508   default:
2509     ShouldNotReachHere();
2510   }
2511   // is_committed is unused.
2512   return checked_mprotect(addr, size, p);
2513 }
2514 
2515 bool os::guard_memory(char* addr, size_t size) {
2516   return checked_mprotect(addr, size, PROT_NONE);
2517 }
2518 
2519 bool os::unguard_memory(char* addr, size_t size) {
2520   return checked_mprotect(addr, size, PROT_READ|PROT_WRITE|PROT_EXEC);
2521 }
2522 
2523 // Large page support
2524 
2525 static size_t _large_page_size = 0;
2526 
2527 // Enable large page support if OS allows that.
2528 void os::large_page_init() {
2529   return; // Nothing to do. See query_multipage_support and friends.
2530 }
2531 
2532 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2533   // reserve_memory_special() is used to allocate large paged memory. On AIX, we implement
2534   // 64k paged memory reservation using the normal memory allocation paths (os::reserve_memory()),
2535   // so this is not needed.
2536   assert(false, "should not be called on AIX");
2537   return NULL;
2538 }
2539 
2540 bool os::release_memory_special(char* base, size_t bytes) {
2541   // Detaching the SHM segment will also delete it, see reserve_memory_special().
2542   Unimplemented();
2543   return false;
2544 }
2545 
2546 size_t os::large_page_size() {
2547   return _large_page_size;
2548 }
2549 
2550 bool os::can_commit_large_page_memory() {
2551   // Does not matter, we do not support huge pages.
2552   return false;
2553 }
2554 
2555 bool os::can_execute_large_page_memory() {
2556   // Does not matter, we do not support huge pages.
2557   return false;
2558 }
2559 
2560 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2561   assert(file_desc >= 0, "file_desc is not valid");
2562   char* result = NULL;
2563 
2564   // Always round to os::vm_page_size(), which may be larger than 4K.
2565   bytes = align_up(bytes, os::vm_page_size());
2566   result = reserve_mmaped_memory(bytes, requested_addr, 0);
2567 
2568   if (result != NULL) {
2569     if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2570       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2571     }
2572   }
2573   return result;
2574 }
2575 
2576 // Reserve memory at an arbitrary address, only if that area is
2577 // available (and not reserved for something else).
2578 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2579   char* addr = NULL;
2580 
2581   // Always round to os::vm_page_size(), which may be larger than 4K.
2582   bytes = align_up(bytes, os::vm_page_size());
2583 
2584   // In 4K mode always use mmap.
2585   // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2586   if (os::vm_page_size() == 4*K) {
2587     return reserve_mmaped_memory(bytes, requested_addr, 0);
2588   } else {
2589     if (bytes >= Use64KPagesThreshold) {
2590       return reserve_shmated_memory(bytes, requested_addr, 0);
2591     } else {
2592       return reserve_mmaped_memory(bytes, requested_addr, 0);
2593     }
2594   }
2595 
2596   return addr;
2597 }
2598 
2599 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2600 void os::infinite_sleep() {
2601   while (true) {    // sleep forever ...
2602     ::sleep(100);   // ... 100 seconds at a time
2603   }
2604 }
2605 
2606 // Used to convert frequent JVM_Yield() to nops
2607 bool os::dont_yield() {
2608   return DontYieldALot;
2609 }
2610 
2611 void os::naked_yield() {
2612   sched_yield();
2613 }
2614 
2615 ////////////////////////////////////////////////////////////////////////////////
2616 // thread priority support
2617 
2618 // From AIX manpage to pthread_setschedparam
2619 // (see: http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?
2620 //    topic=/com.ibm.aix.basetechref/doc/basetrf1/pthread_setschedparam.htm):
2621 //
2622 // "If schedpolicy is SCHED_OTHER, then sched_priority must be in the
2623 // range from 40 to 80, where 40 is the least favored priority and 80
2624 // is the most favored."
2625 //
2626 // (Actually, I doubt this even has an impact on AIX, as we do kernel
2627 // scheduling there; however, this still leaves iSeries.)
2628 //
2629 // We use the same values for AIX and PASE.
2630 int os::java_to_os_priority[CriticalPriority + 1] = {
2631   54,             // 0 Entry should never be used
2632 
2633   55,             // 1 MinPriority
2634   55,             // 2
2635   56,             // 3
2636 
2637   56,             // 4
2638   57,             // 5 NormPriority
2639   57,             // 6
2640 
2641   58,             // 7
2642   58,             // 8
2643   59,             // 9 NearMaxPriority
2644 
2645   60,             // 10 MaxPriority
2646 
2647   60              // 11 CriticalPriority
2648 };
2649 
2650 static int prio_init() {
2651   if (ThreadPriorityPolicy == 1) {
2652     if (geteuid() != 0) {
2653       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2654         warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
2655                 "e.g., being the root user. If the necessary permission is not " \
2656                 "possessed, changes to priority will be silently ignored.");
2657       }
2658     }
2659   }
2660   if (UseCriticalJavaThreadPriority) {
2661     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2662   }
2663   return 0;
2664 }
2665 
2666 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2667   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2668   pthread_t thr = thread->osthread()->pthread_id();
2669   int policy = SCHED_OTHER;
2670   struct sched_param param;
2671   param.sched_priority = newpri;
2672   int ret = pthread_setschedparam(thr, policy, &param);
2673 
2674   if (ret != 0) {
2675     trcVerbose("Could not change priority for thread %d to %d (error %d, %s)",
2676         (int)thr, newpri, ret, os::errno_name(ret));
2677   }
2678   return (ret == 0) ? OS_OK : OS_ERR;
2679 }
2680 
2681 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2682   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2683     *priority_ptr = java_to_os_priority[NormPriority];
2684     return OS_OK;
2685   }
2686   pthread_t thr = thread->osthread()->pthread_id();
2687   int policy = SCHED_OTHER;
2688   struct sched_param param;
2689   int ret = pthread_getschedparam(thr, &policy, &param);
2690   *priority_ptr = param.sched_priority;
2691 
2692   return (ret == 0) ? OS_OK : OS_ERR;
2693 }
2694 
2695 ////////////////////////////////////////////////////////////////////////////////
2696 // suspend/resume support
2697 
2698 //  The low-level signal-based suspend/resume support is a remnant from the
2699 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2700 //  within hotspot. Currently used by JFR's OSThreadSampler
2701 //
2702 //  The remaining code is greatly simplified from the more general suspension
2703 //  code that used to be used.
2704 //
2705 //  The protocol is quite simple:
2706 //  - suspend:
2707 //      - sends a signal to the target thread
2708 //      - polls the suspend state of the osthread using a yield loop
2709 //      - target thread signal handler (SR_handler) sets suspend state
2710 //        and blocks in sigsuspend until continued
2711 //  - resume:
2712 //      - sets target osthread state to continue
2713 //      - sends signal to end the sigsuspend loop in the SR_handler
2714 //
2715 //  Note that the SR_lock plays no role in this suspend/resume protocol,
2716 //  but is checked for NULL in SR_handler as a thread termination indicator.
2717 //  The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
2718 //
2719 //  Note that resume_clear_context() and suspend_save_context() are needed
2720 //  by SR_handler(), so that fetch_frame_from_ucontext() works,
2721 //  which in part is used by:
2722 //    - Forte Analyzer: AsyncGetCallTrace()
2723 //    - StackBanging: get_frame_at_stack_banging_point()
2724 
2725 static void resume_clear_context(OSThread *osthread) {
2726   osthread->set_ucontext(NULL);
2727   osthread->set_siginfo(NULL);
2728 }
2729 
2730 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2731   osthread->set_ucontext(context);
2732   osthread->set_siginfo(siginfo);
2733 }
2734 
2735 //
2736 // Handler function invoked when a thread's execution is suspended or
2737 // resumed. We have to be careful that only async-safe functions are
2738 // called here (Note: most pthread functions are not async safe and
2739 // should be avoided.)
2740 //
2741 // Note: sigwait() is a more natural fit than sigsuspend() from an
2742 // interface point of view, but sigwait() prevents the signal hander
2743 // from being run. libpthread would get very confused by not having
2744 // its signal handlers run and prevents sigwait()'s use with the
2745 // mutex granting granting signal.
2746 //
2747 // Currently only ever called on the VMThread and JavaThreads (PC sampling).
2748 //
2749 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2750   // Save and restore errno to avoid confusing native code with EINTR
2751   // after sigsuspend.
2752   int old_errno = errno;
2753 
2754   Thread* thread = Thread::current_or_null_safe();
2755   assert(thread != NULL, "Missing current thread in SR_handler");
2756 
2757   // On some systems we have seen signal delivery get "stuck" until the signal
2758   // mask is changed as part of thread termination. Check that the current thread
2759   // has not already terminated (via SR_lock()) - else the following assertion
2760   // will fail because the thread is no longer a JavaThread as the ~JavaThread
2761   // destructor has completed.
2762 
2763   if (thread->SR_lock() == NULL) {
2764     return;
2765   }
2766 
2767   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2768 
2769   OSThread* osthread = thread->osthread();
2770 
2771   os::SuspendResume::State current = osthread->sr.state();
2772   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2773     suspend_save_context(osthread, siginfo, context);
2774 
2775     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2776     os::SuspendResume::State state = osthread->sr.suspended();
2777     if (state == os::SuspendResume::SR_SUSPENDED) {
2778       sigset_t suspend_set;  // signals for sigsuspend()
2779       sigemptyset(&suspend_set);
2780       // get current set of blocked signals and unblock resume signal
2781       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2782       sigdelset(&suspend_set, SR_signum);
2783 
2784       // wait here until we are resumed
2785       while (1) {
2786         sigsuspend(&suspend_set);
2787 
2788         os::SuspendResume::State result = osthread->sr.running();
2789         if (result == os::SuspendResume::SR_RUNNING) {
2790           break;
2791         }
2792       }
2793 
2794     } else if (state == os::SuspendResume::SR_RUNNING) {
2795       // request was cancelled, continue
2796     } else {
2797       ShouldNotReachHere();
2798     }
2799 
2800     resume_clear_context(osthread);
2801   } else if (current == os::SuspendResume::SR_RUNNING) {
2802     // request was cancelled, continue
2803   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2804     // ignore
2805   } else {
2806     ShouldNotReachHere();
2807   }
2808 
2809   errno = old_errno;
2810 }
2811 
2812 static int SR_initialize() {
2813   struct sigaction act;
2814   char *s;
2815   // Get signal number to use for suspend/resume
2816   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2817     int sig = ::strtol(s, 0, 10);
2818     if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
2819         sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
2820       SR_signum = sig;
2821     } else {
2822       warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2823               sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2824     }
2825   }
2826 
2827   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2828         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2829 
2830   sigemptyset(&SR_sigset);
2831   sigaddset(&SR_sigset, SR_signum);
2832 
2833   // Set up signal handler for suspend/resume.
2834   act.sa_flags = SA_RESTART|SA_SIGINFO;
2835   act.sa_handler = (void (*)(int)) SR_handler;
2836 
2837   // SR_signum is blocked by default.
2838   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2839 
2840   if (sigaction(SR_signum, &act, 0) == -1) {
2841     return -1;
2842   }
2843 
2844   // Save signal flag
2845   os::Aix::set_our_sigflags(SR_signum, act.sa_flags);
2846   return 0;
2847 }
2848 
2849 static int SR_finalize() {
2850   return 0;
2851 }
2852 
2853 static int sr_notify(OSThread* osthread) {
2854   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2855   assert_status(status == 0, status, "pthread_kill");
2856   return status;
2857 }
2858 
2859 // "Randomly" selected value for how long we want to spin
2860 // before bailing out on suspending a thread, also how often
2861 // we send a signal to a thread we want to resume
2862 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2863 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2864 
2865 // returns true on success and false on error - really an error is fatal
2866 // but this seems the normal response to library errors
2867 static bool do_suspend(OSThread* osthread) {
2868   assert(osthread->sr.is_running(), "thread should be running");
2869   // mark as suspended and send signal
2870 
2871   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2872     // failed to switch, state wasn't running?
2873     ShouldNotReachHere();
2874     return false;
2875   }
2876 
2877   if (sr_notify(osthread) != 0) {
2878     // try to cancel, switch to running
2879 
2880     os::SuspendResume::State result = osthread->sr.cancel_suspend();
2881     if (result == os::SuspendResume::SR_RUNNING) {
2882       // cancelled
2883       return false;
2884     } else if (result == os::SuspendResume::SR_SUSPENDED) {
2885       // somehow managed to suspend
2886       return true;
2887     } else {
2888       ShouldNotReachHere();
2889       return false;
2890     }
2891   }
2892 
2893   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2894 
2895   for (int n = 0; !osthread->sr.is_suspended(); n++) {
2896     for (int i = 0; i < RANDOMLY_LARGE_INTEGER2 && !osthread->sr.is_suspended(); i++) {
2897       os::naked_yield();
2898     }
2899 
2900     // timeout, try to cancel the request
2901     if (n >= RANDOMLY_LARGE_INTEGER) {
2902       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2903       if (cancelled == os::SuspendResume::SR_RUNNING) {
2904         return false;
2905       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2906         return true;
2907       } else {
2908         ShouldNotReachHere();
2909         return false;
2910       }
2911     }
2912   }
2913 
2914   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2915   return true;
2916 }
2917 
2918 static void do_resume(OSThread* osthread) {
2919   //assert(osthread->sr.is_suspended(), "thread should be suspended");
2920 
2921   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2922     // failed to switch to WAKEUP_REQUEST
2923     ShouldNotReachHere();
2924     return;
2925   }
2926 
2927   while (!osthread->sr.is_running()) {
2928     if (sr_notify(osthread) == 0) {
2929       for (int n = 0; n < RANDOMLY_LARGE_INTEGER && !osthread->sr.is_running(); n++) {
2930         for (int i = 0; i < 100 && !osthread->sr.is_running(); i++) {
2931           os::naked_yield();
2932         }
2933       }
2934     } else {
2935       ShouldNotReachHere();
2936     }
2937   }
2938 
2939   guarantee(osthread->sr.is_running(), "Must be running!");
2940 }
2941 
2942 ///////////////////////////////////////////////////////////////////////////////////
2943 // signal handling (except suspend/resume)
2944 
2945 // This routine may be used by user applications as a "hook" to catch signals.
2946 // The user-defined signal handler must pass unrecognized signals to this
2947 // routine, and if it returns true (non-zero), then the signal handler must
2948 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2949 // routine will never retun false (zero), but instead will execute a VM panic
2950 // routine kill the process.
2951 //
2952 // If this routine returns false, it is OK to call it again. This allows
2953 // the user-defined signal handler to perform checks either before or after
2954 // the VM performs its own checks. Naturally, the user code would be making
2955 // a serious error if it tried to handle an exception (such as a null check
2956 // or breakpoint) that the VM was generating for its own correct operation.
2957 //
2958 // This routine may recognize any of the following kinds of signals:
2959 //   SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2960 // It should be consulted by handlers for any of those signals.
2961 //
2962 // The caller of this routine must pass in the three arguments supplied
2963 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2964 // field of the structure passed to sigaction(). This routine assumes that
2965 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2966 //
2967 // Note that the VM will print warnings if it detects conflicting signal
2968 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2969 //
2970 extern "C" JNIEXPORT int
2971 JVM_handle_aix_signal(int signo, siginfo_t* siginfo, void* ucontext, int abort_if_unrecognized);
2972 
2973 // Set thread signal mask (for some reason on AIX sigthreadmask() seems
2974 // to be the thing to call; documentation is not terribly clear about whether
2975 // pthread_sigmask also works, and if it does, whether it does the same.
2976 bool set_thread_signal_mask(int how, const sigset_t* set, sigset_t* oset) {
2977   const int rc = ::pthread_sigmask(how, set, oset);
2978   // return value semantics differ slightly for error case:
2979   // pthread_sigmask returns error number, sigthreadmask -1 and sets global errno
2980   // (so, pthread_sigmask is more theadsafe for error handling)
2981   // But success is always 0.
2982   return rc == 0 ? true : false;
2983 }
2984 
2985 // Function to unblock all signals which are, according
2986 // to POSIX, typical program error signals. If they happen while being blocked,
2987 // they typically will bring down the process immediately.
2988 bool unblock_program_error_signals() {
2989   sigset_t set;
2990   ::sigemptyset(&set);
2991   ::sigaddset(&set, SIGILL);
2992   ::sigaddset(&set, SIGBUS);
2993   ::sigaddset(&set, SIGFPE);
2994   ::sigaddset(&set, SIGSEGV);
2995   return set_thread_signal_mask(SIG_UNBLOCK, &set, NULL);
2996 }
2997 
2998 // Renamed from 'signalHandler' to avoid collision with other shared libs.
2999 static void javaSignalHandler(int sig, siginfo_t* info, void* uc) {
3000   assert(info != NULL && uc != NULL, "it must be old kernel");
3001 
3002   // Never leave program error signals blocked;
3003   // on all our platforms they would bring down the process immediately when
3004   // getting raised while being blocked.
3005   unblock_program_error_signals();
3006 
3007   int orig_errno = errno;  // Preserve errno value over signal handler.
3008   JVM_handle_aix_signal(sig, info, uc, true);
3009   errno = orig_errno;
3010 }
3011 
3012 // This boolean allows users to forward their own non-matching signals
3013 // to JVM_handle_aix_signal, harmlessly.
3014 bool os::Aix::signal_handlers_are_installed = false;
3015 
3016 // For signal-chaining
3017 bool os::Aix::libjsig_is_loaded = false;
3018 typedef struct sigaction *(*get_signal_t)(int);
3019 get_signal_t os::Aix::get_signal_action = NULL;
3020 
3021 struct sigaction* os::Aix::get_chained_signal_action(int sig) {
3022   struct sigaction *actp = NULL;
3023 
3024   if (libjsig_is_loaded) {
3025     // Retrieve the old signal handler from libjsig
3026     actp = (*get_signal_action)(sig);
3027   }
3028   if (actp == NULL) {
3029     // Retrieve the preinstalled signal handler from jvm
3030     actp = os::Posix::get_preinstalled_handler(sig);
3031   }
3032 
3033   return actp;
3034 }
3035 
3036 static bool call_chained_handler(struct sigaction *actp, int sig,
3037                                  siginfo_t *siginfo, void *context) {
3038   // Call the old signal handler
3039   if (actp->sa_handler == SIG_DFL) {
3040     // It's more reasonable to let jvm treat it as an unexpected exception
3041     // instead of taking the default action.
3042     return false;
3043   } else if (actp->sa_handler != SIG_IGN) {
3044     if ((actp->sa_flags & SA_NODEFER) == 0) {
3045       // automaticlly block the signal
3046       sigaddset(&(actp->sa_mask), sig);
3047     }
3048 
3049     sa_handler_t hand = NULL;
3050     sa_sigaction_t sa = NULL;
3051     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3052     // retrieve the chained handler
3053     if (siginfo_flag_set) {
3054       sa = actp->sa_sigaction;
3055     } else {
3056       hand = actp->sa_handler;
3057     }
3058 
3059     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3060       actp->sa_handler = SIG_DFL;
3061     }
3062 
3063     // try to honor the signal mask
3064     sigset_t oset;
3065     sigemptyset(&oset);
3066     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3067 
3068     // call into the chained handler
3069     if (siginfo_flag_set) {
3070       (*sa)(sig, siginfo, context);
3071     } else {
3072       (*hand)(sig);
3073     }
3074 
3075     // restore the signal mask
3076     pthread_sigmask(SIG_SETMASK, &oset, NULL);
3077   }
3078   // Tell jvm's signal handler the signal is taken care of.
3079   return true;
3080 }
3081 
3082 bool os::Aix::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3083   bool chained = false;
3084   // signal-chaining
3085   if (UseSignalChaining) {
3086     struct sigaction *actp = get_chained_signal_action(sig);
3087     if (actp != NULL) {
3088       chained = call_chained_handler(actp, sig, siginfo, context);
3089     }
3090   }
3091   return chained;
3092 }
3093 
3094 // for diagnostic
3095 int sigflags[NSIG];
3096 
3097 int os::Aix::get_our_sigflags(int sig) {
3098   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3099   return sigflags[sig];
3100 }
3101 
3102 void os::Aix::set_our_sigflags(int sig, int flags) {
3103   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3104   if (sig > 0 && sig < NSIG) {
3105     sigflags[sig] = flags;
3106   }
3107 }
3108 
3109 void os::Aix::set_signal_handler(int sig, bool set_installed) {
3110   // Check for overwrite.
3111   struct sigaction oldAct;
3112   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3113 
3114   void* oldhand = oldAct.sa_sigaction
3115     ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3116     : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3117   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3118       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3119       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)javaSignalHandler)) {
3120     if (AllowUserSignalHandlers || !set_installed) {
3121       // Do not overwrite; user takes responsibility to forward to us.
3122       return;
3123     } else if (UseSignalChaining) {
3124       // save the old handler in jvm
3125       os::Posix::save_preinstalled_handler(sig, oldAct);
3126       // libjsig also interposes the sigaction() call below and saves the
3127       // old sigaction on it own.
3128     } else {
3129       fatal("Encountered unexpected pre-existing sigaction handler "
3130             "%#lx for signal %d.", (long)oldhand, sig);
3131     }
3132   }
3133 
3134   struct sigaction sigAct;
3135   sigfillset(&(sigAct.sa_mask));
3136   if (!set_installed) {
3137     sigAct.sa_handler = SIG_DFL;
3138     sigAct.sa_flags = SA_RESTART;
3139   } else {
3140     sigAct.sa_sigaction = javaSignalHandler;
3141     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3142   }
3143   // Save flags, which are set by ours
3144   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3145   sigflags[sig] = sigAct.sa_flags;
3146 
3147   int ret = sigaction(sig, &sigAct, &oldAct);
3148   assert(ret == 0, "check");
3149 
3150   void* oldhand2 = oldAct.sa_sigaction
3151                  ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3152                  : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3153   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3154 }
3155 
3156 // install signal handlers for signals that HotSpot needs to
3157 // handle in order to support Java-level exception handling.
3158 void os::Aix::install_signal_handlers() {
3159   if (!signal_handlers_are_installed) {
3160     signal_handlers_are_installed = true;
3161 
3162     // signal-chaining
3163     typedef void (*signal_setting_t)();
3164     signal_setting_t begin_signal_setting = NULL;
3165     signal_setting_t end_signal_setting = NULL;
3166     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3167                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3168     if (begin_signal_setting != NULL) {
3169       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3170                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3171       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3172                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3173       libjsig_is_loaded = true;
3174       assert(UseSignalChaining, "should enable signal-chaining");
3175     }
3176     if (libjsig_is_loaded) {
3177       // Tell libjsig jvm is setting signal handlers.
3178       (*begin_signal_setting)();
3179     }
3180 
3181     set_signal_handler(SIGSEGV, true);
3182     set_signal_handler(SIGPIPE, true);
3183     set_signal_handler(SIGBUS, true);
3184     set_signal_handler(SIGILL, true);
3185     set_signal_handler(SIGFPE, true);
3186     set_signal_handler(SIGTRAP, true);
3187     set_signal_handler(SIGXFSZ, true);
3188 
3189     if (libjsig_is_loaded) {
3190       // Tell libjsig jvm finishes setting signal handlers.
3191       (*end_signal_setting)();
3192     }
3193 
3194     // We don't activate signal checker if libjsig is in place, we trust ourselves
3195     // and if UserSignalHandler is installed all bets are off.
3196     // Log that signal checking is off only if -verbose:jni is specified.
3197     if (CheckJNICalls) {
3198       if (libjsig_is_loaded) {
3199         tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3200         check_signals = false;
3201       }
3202       if (AllowUserSignalHandlers) {
3203         tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3204         check_signals = false;
3205       }
3206       // Need to initialize check_signal_done.
3207       ::sigemptyset(&check_signal_done);
3208     }
3209   }
3210 }
3211 
3212 static const char* get_signal_handler_name(address handler,
3213                                            char* buf, int buflen) {
3214   int offset;
3215   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3216   if (found) {
3217     // skip directory names
3218     const char *p1, *p2;
3219     p1 = buf;
3220     size_t len = strlen(os::file_separator());
3221     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3222     // The way os::dll_address_to_library_name is implemented on Aix
3223     // right now, it always returns -1 for the offset which is not
3224     // terribly informative.
3225     // Will fix that. For now, omit the offset.
3226     jio_snprintf(buf, buflen, "%s", p1);
3227   } else {
3228     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3229   }
3230   return buf;
3231 }
3232 
3233 static void print_signal_handler(outputStream* st, int sig,
3234                                  char* buf, size_t buflen) {
3235   struct sigaction sa;
3236   sigaction(sig, NULL, &sa);
3237 
3238   st->print("%s: ", os::exception_name(sig, buf, buflen));
3239 
3240   address handler = (sa.sa_flags & SA_SIGINFO)
3241     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3242     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3243 
3244   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3245     st->print("SIG_DFL");
3246   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3247     st->print("SIG_IGN");
3248   } else {
3249     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3250   }
3251 
3252   // Print readable mask.
3253   st->print(", sa_mask[0]=");
3254   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3255 
3256   address rh = VMError::get_resetted_sighandler(sig);
3257   // May be, handler was resetted by VMError?
3258   if (rh != NULL) {
3259     handler = rh;
3260     sa.sa_flags = VMError::get_resetted_sigflags(sig);
3261   }
3262 
3263   // Print textual representation of sa_flags.
3264   st->print(", sa_flags=");
3265   os::Posix::print_sa_flags(st, sa.sa_flags);
3266 
3267   // Check: is it our handler?
3268   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)javaSignalHandler) ||
3269       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3270     // It is our signal handler.
3271     // Check for flags, reset system-used one!
3272     if ((int)sa.sa_flags != os::Aix::get_our_sigflags(sig)) {
3273       st->print(", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3274                 os::Aix::get_our_sigflags(sig));
3275     }
3276   }
3277   st->cr();
3278 }
3279 
3280 #define DO_SIGNAL_CHECK(sig) \
3281   if (!sigismember(&check_signal_done, sig)) \
3282     os::Aix::check_signal_handler(sig)
3283 
3284 // This method is a periodic task to check for misbehaving JNI applications
3285 // under CheckJNI, we can add any periodic checks here
3286 
3287 void os::run_periodic_checks() {
3288 
3289   if (check_signals == false) return;
3290 
3291   // SEGV and BUS if overridden could potentially prevent
3292   // generation of hs*.log in the event of a crash, debugging
3293   // such a case can be very challenging, so we absolutely
3294   // check the following for a good measure:
3295   DO_SIGNAL_CHECK(SIGSEGV);
3296   DO_SIGNAL_CHECK(SIGILL);
3297   DO_SIGNAL_CHECK(SIGFPE);
3298   DO_SIGNAL_CHECK(SIGBUS);
3299   DO_SIGNAL_CHECK(SIGPIPE);
3300   DO_SIGNAL_CHECK(SIGXFSZ);
3301   if (UseSIGTRAP) {
3302     DO_SIGNAL_CHECK(SIGTRAP);
3303   }
3304 
3305   // ReduceSignalUsage allows the user to override these handlers
3306   // see comments at the very top and jvm_md.h
3307   if (!ReduceSignalUsage) {
3308     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3309     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3310     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3311     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3312   }
3313 
3314   DO_SIGNAL_CHECK(SR_signum);
3315 }
3316 
3317 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3318 
3319 static os_sigaction_t os_sigaction = NULL;
3320 
3321 void os::Aix::check_signal_handler(int sig) {
3322   char buf[O_BUFLEN];
3323   address jvmHandler = NULL;
3324 
3325   struct sigaction act;
3326   if (os_sigaction == NULL) {
3327     // only trust the default sigaction, in case it has been interposed
3328     os_sigaction = CAST_TO_FN_PTR(os_sigaction_t, dlsym(RTLD_DEFAULT, "sigaction"));
3329     if (os_sigaction == NULL) return;
3330   }
3331 
3332   os_sigaction(sig, (struct sigaction*)NULL, &act);
3333 
3334   address thisHandler = (act.sa_flags & SA_SIGINFO)
3335     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3336     : CAST_FROM_FN_PTR(address, act.sa_handler);
3337 
3338   switch(sig) {
3339   case SIGSEGV:
3340   case SIGBUS:
3341   case SIGFPE:
3342   case SIGPIPE:
3343   case SIGILL:
3344   case SIGXFSZ:
3345     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)javaSignalHandler);
3346     break;
3347 
3348   case SHUTDOWN1_SIGNAL:
3349   case SHUTDOWN2_SIGNAL:
3350   case SHUTDOWN3_SIGNAL:
3351   case BREAK_SIGNAL:
3352     jvmHandler = (address)user_handler();
3353     break;
3354 
3355   default:
3356     if (sig == SR_signum) {
3357       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3358     } else {
3359       return;
3360     }
3361     break;
3362   }
3363 
3364   if (thisHandler != jvmHandler) {
3365     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3366     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3367     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3368     // No need to check this sig any longer
3369     sigaddset(&check_signal_done, sig);
3370     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3371     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3372       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3373                     exception_name(sig, buf, O_BUFLEN));
3374     }
3375   } else if (os::Aix::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Aix::get_our_sigflags(sig)) {
3376     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3377     tty->print("expected:");
3378     os::Posix::print_sa_flags(tty, os::Aix::get_our_sigflags(sig));
3379     tty->cr();
3380     tty->print("  found:");
3381     os::Posix::print_sa_flags(tty, act.sa_flags);
3382     tty->cr();
3383     // No need to check this sig any longer
3384     sigaddset(&check_signal_done, sig);
3385   }
3386 
3387   // Dump all the signal
3388   if (sigismember(&check_signal_done, sig)) {
3389     print_signal_handlers(tty, buf, O_BUFLEN);
3390   }
3391 }
3392 
3393 // To install functions for atexit system call
3394 extern "C" {
3395   static void perfMemory_exit_helper() {
3396     perfMemory_exit();
3397   }
3398 }
3399 
3400 // This is called _before_ the most of global arguments have been parsed.
3401 void os::init(void) {
3402   // This is basic, we want to know if that ever changes.
3403   // (Shared memory boundary is supposed to be a 256M aligned.)
3404   assert(SHMLBA == ((uint64_t)0x10000000ULL)/*256M*/, "unexpected");
3405 
3406   // Record process break at startup.
3407   g_brk_at_startup = (address) ::sbrk(0);
3408   assert(g_brk_at_startup != (address) -1, "sbrk failed");
3409 
3410   // First off, we need to know whether we run on AIX or PASE, and
3411   // the OS level we run on.
3412   os::Aix::initialize_os_info();
3413 
3414   // Scan environment (SPEC1170 behaviour, etc).
3415   os::Aix::scan_environment();
3416 
3417   // Probe multipage support.
3418   query_multipage_support();
3419 
3420   // Act like we only have one page size by eliminating corner cases which
3421   // we did not support very well anyway.
3422   // We have two input conditions:
3423   // 1) Data segment page size. This is controlled by linker setting (datapsize) on the
3424   //    launcher, and/or by LDR_CNTRL environment variable. The latter overrules the linker
3425   //    setting.
3426   //    Data segment page size is important for us because it defines the thread stack page
3427   //    size, which is needed for guard page handling, stack banging etc.
3428   // 2) The ability to allocate 64k pages dynamically. If this is a given, java heap can
3429   //    and should be allocated with 64k pages.
3430   //
3431   // So, we do the following:
3432   // LDR_CNTRL    can_use_64K_pages_dynamically       what we do                      remarks
3433   // 4K           no                                  4K                              old systems (aix 5.2, as/400 v5r4) or new systems with AME activated
3434   // 4k           yes                                 64k (treat 4k stacks as 64k)    different loader than java and standard settings
3435   // 64k          no              --- AIX 5.2 ? ---
3436   // 64k          yes                                 64k                             new systems and standard java loader (we set datapsize=64k when linking)
3437 
3438   // We explicitly leave no option to change page size, because only upgrading would work,
3439   // not downgrading (if stack page size is 64k you cannot pretend its 4k).
3440 
3441   if (g_multipage_support.datapsize == 4*K) {
3442     // datapsize = 4K. Data segment, thread stacks are 4K paged.
3443     if (g_multipage_support.can_use_64K_pages) {
3444       // .. but we are able to use 64K pages dynamically.
3445       // This would be typical for java launchers which are not linked
3446       // with datapsize=64K (like, any other launcher but our own).
3447       //
3448       // In this case it would be smart to allocate the java heap with 64K
3449       // to get the performance benefit, and to fake 64k pages for the
3450       // data segment (when dealing with thread stacks).
3451       //
3452       // However, leave a possibility to downgrade to 4K, using
3453       // -XX:-Use64KPages.
3454       if (Use64KPages) {
3455         trcVerbose("64K page mode (faked for data segment)");
3456         Aix::_page_size = 64*K;
3457       } else {
3458         trcVerbose("4K page mode (Use64KPages=off)");
3459         Aix::_page_size = 4*K;
3460       }
3461     } else {
3462       // .. and not able to allocate 64k pages dynamically. Here, just
3463       // fall back to 4K paged mode and use mmap for everything.
3464       trcVerbose("4K page mode");
3465       Aix::_page_size = 4*K;
3466       FLAG_SET_ERGO(Use64KPages, false);
3467     }
3468   } else {
3469     // datapsize = 64k. Data segment, thread stacks are 64k paged.
3470     // This normally means that we can allocate 64k pages dynamically.
3471     // (There is one special case where this may be false: EXTSHM=on.
3472     // but we decided to not support that mode).
3473     assert0(g_multipage_support.can_use_64K_pages);
3474     Aix::_page_size = 64*K;
3475     trcVerbose("64K page mode");
3476     FLAG_SET_ERGO(Use64KPages, true);
3477   }
3478 
3479   // For now UseLargePages is just ignored.
3480   FLAG_SET_ERGO(UseLargePages, false);
3481   _page_sizes[0] = 0;
3482 
3483   // debug trace
3484   trcVerbose("os::vm_page_size %s", describe_pagesize(os::vm_page_size()));
3485 
3486   // Next, we need to initialize libo4 and libperfstat libraries.
3487   if (os::Aix::on_pase()) {
3488     os::Aix::initialize_libo4();
3489   } else {
3490     os::Aix::initialize_libperfstat();
3491   }
3492 
3493   // Reset the perfstat information provided by ODM.
3494   if (os::Aix::on_aix()) {
3495     libperfstat::perfstat_reset();
3496   }
3497 
3498   // Now initialze basic system properties. Note that for some of the values we
3499   // need libperfstat etc.
3500   os::Aix::initialize_system_info();
3501 
3502   clock_tics_per_sec = sysconf(_SC_CLK_TCK);
3503 
3504   init_random(1234567);
3505 
3506   // _main_thread points to the thread that created/loaded the JVM.
3507   Aix::_main_thread = pthread_self();
3508 
3509   initial_time_count = javaTimeNanos();
3510 
3511   os::Posix::init();
3512 }
3513 
3514 // This is called _after_ the global arguments have been parsed.
3515 jint os::init_2(void) {
3516 
3517   // This could be set after os::Posix::init() but all platforms
3518   // have to set it the same so we have to mirror Solaris.
3519   DEBUG_ONLY(os::set_mutex_init_done();)
3520 
3521   os::Posix::init_2();
3522 
3523   if (os::Aix::on_pase()) {
3524     trcVerbose("Running on PASE.");
3525   } else {
3526     trcVerbose("Running on AIX (not PASE).");
3527   }
3528 
3529   trcVerbose("processor count: %d", os::_processor_count);
3530   trcVerbose("physical memory: %lu", Aix::_physical_memory);
3531 
3532   // Initially build up the loaded dll map.
3533   LoadedLibraries::reload();
3534   if (Verbose) {
3535     trcVerbose("Loaded Libraries: ");
3536     LoadedLibraries::print(tty);
3537   }
3538 
3539   // initialize suspend/resume support - must do this before signal_sets_init()
3540   if (SR_initialize() != 0) {
3541     perror("SR_initialize failed");
3542     return JNI_ERR;
3543   }
3544 
3545   Aix::signal_sets_init();
3546   Aix::install_signal_handlers();
3547   // Initialize data for jdk.internal.misc.Signal
3548   if (!ReduceSignalUsage) {
3549     jdk_misc_signal_init();
3550   }
3551 
3552   // Check and sets minimum stack sizes against command line options
3553   if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
3554     return JNI_ERR;
3555   }
3556 
3557   if (UseNUMA) {
3558     UseNUMA = false;
3559     warning("NUMA optimizations are not available on this OS.");
3560   }
3561 
3562   if (MaxFDLimit) {
3563     // Set the number of file descriptors to max. print out error
3564     // if getrlimit/setrlimit fails but continue regardless.
3565     struct rlimit nbr_files;
3566     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3567     if (status != 0) {
3568       log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3569     } else {
3570       nbr_files.rlim_cur = nbr_files.rlim_max;
3571       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3572       if (status != 0) {
3573         log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3574       }
3575     }
3576   }
3577 
3578   if (PerfAllowAtExitRegistration) {
3579     // Only register atexit functions if PerfAllowAtExitRegistration is set.
3580     // At exit functions can be delayed until process exit time, which
3581     // can be problematic for embedded VM situations. Embedded VMs should
3582     // call DestroyJavaVM() to assure that VM resources are released.
3583 
3584     // Note: perfMemory_exit_helper atexit function may be removed in
3585     // the future if the appropriate cleanup code can be added to the
3586     // VM_Exit VMOperation's doit method.
3587     if (atexit(perfMemory_exit_helper) != 0) {
3588       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
3589     }
3590   }
3591 
3592   // initialize thread priority policy
3593   prio_init();
3594 
3595   return JNI_OK;
3596 }
3597 
3598 // Mark the polling page as unreadable
3599 void os::make_polling_page_unreadable(void) {
3600   if (!guard_memory((char*)_polling_page, Aix::page_size())) {
3601     fatal("Could not disable polling page");
3602   }
3603 };
3604 
3605 // Mark the polling page as readable
3606 void os::make_polling_page_readable(void) {
3607   // Changed according to os_linux.cpp.
3608   if (!checked_mprotect((char *)_polling_page, Aix::page_size(), PROT_READ)) {
3609     fatal("Could not enable polling page at " PTR_FORMAT, _polling_page);
3610   }
3611 };
3612 
3613 int os::active_processor_count() {
3614   // User has overridden the number of active processors
3615   if (ActiveProcessorCount > 0) {
3616     log_trace(os)("active_processor_count: "
3617                   "active processor count set by user : %d",
3618                   ActiveProcessorCount);
3619     return ActiveProcessorCount;
3620   }
3621 
3622   int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
3623   assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check");
3624   return online_cpus;
3625 }
3626 
3627 void os::set_native_thread_name(const char *name) {
3628   // Not yet implemented.
3629   return;
3630 }
3631 
3632 bool os::bind_to_processor(uint processor_id) {
3633   // Not yet implemented.
3634   return false;
3635 }
3636 
3637 void os::SuspendedThreadTask::internal_do_task() {
3638   if (do_suspend(_thread->osthread())) {
3639     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3640     do_task(context);
3641     do_resume(_thread->osthread());
3642   }
3643 }
3644 
3645 ////////////////////////////////////////////////////////////////////////////////
3646 // debug support
3647 
3648 bool os::find(address addr, outputStream* st) {
3649 
3650   st->print(PTR_FORMAT ": ", addr);
3651 
3652   loaded_module_t lm;
3653   if (LoadedLibraries::find_for_text_address(addr, &lm) != NULL ||
3654       LoadedLibraries::find_for_data_address(addr, &lm) != NULL) {
3655     st->print_cr("%s", lm.path);
3656     return true;
3657   }
3658 
3659   return false;
3660 }
3661 
3662 ////////////////////////////////////////////////////////////////////////////////
3663 // misc
3664 
3665 // This does not do anything on Aix. This is basically a hook for being
3666 // able to use structured exception handling (thread-local exception filters)
3667 // on, e.g., Win32.
3668 void
3669 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
3670                          JavaCallArguments* args, Thread* thread) {
3671   f(value, method, args, thread);
3672 }
3673 
3674 void os::print_statistics() {
3675 }
3676 
3677 bool os::message_box(const char* title, const char* message) {
3678   int i;
3679   fdStream err(defaultStream::error_fd());
3680   for (i = 0; i < 78; i++) err.print_raw("=");
3681   err.cr();
3682   err.print_raw_cr(title);
3683   for (i = 0; i < 78; i++) err.print_raw("-");
3684   err.cr();
3685   err.print_raw_cr(message);
3686   for (i = 0; i < 78; i++) err.print_raw("=");
3687   err.cr();
3688 
3689   char buf[16];
3690   // Prevent process from exiting upon "read error" without consuming all CPU
3691   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3692 
3693   return buf[0] == 'y' || buf[0] == 'Y';
3694 }
3695 
3696 // Is a (classpath) directory empty?
3697 bool os::dir_is_empty(const char* path) {
3698   DIR *dir = NULL;
3699   struct dirent *ptr;
3700 
3701   dir = opendir(path);
3702   if (dir == NULL) return true;
3703 
3704   /* Scan the directory */
3705   bool result = true;
3706   while (result && (ptr = readdir(dir)) != NULL) {
3707     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3708       result = false;
3709     }
3710   }
3711   closedir(dir);
3712   return result;
3713 }
3714 
3715 // This code originates from JDK's sysOpen and open64_w
3716 // from src/solaris/hpi/src/system_md.c
3717 
3718 int os::open(const char *path, int oflag, int mode) {
3719 
3720   if (strlen(path) > MAX_PATH - 1) {
3721     errno = ENAMETOOLONG;
3722     return -1;
3723   }
3724   int fd;
3725 
3726   fd = ::open64(path, oflag, mode);
3727   if (fd == -1) return -1;
3728 
3729   // If the open succeeded, the file might still be a directory.
3730   {
3731     struct stat64 buf64;
3732     int ret = ::fstat64(fd, &buf64);
3733     int st_mode = buf64.st_mode;
3734 
3735     if (ret != -1) {
3736       if ((st_mode & S_IFMT) == S_IFDIR) {
3737         errno = EISDIR;
3738         ::close(fd);
3739         return -1;
3740       }
3741     } else {
3742       ::close(fd);
3743       return -1;
3744     }
3745   }
3746 
3747   // All file descriptors that are opened in the JVM and not
3748   // specifically destined for a subprocess should have the
3749   // close-on-exec flag set. If we don't set it, then careless 3rd
3750   // party native code might fork and exec without closing all
3751   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3752   // UNIXProcess.c), and this in turn might:
3753   //
3754   // - cause end-of-file to fail to be detected on some file
3755   //   descriptors, resulting in mysterious hangs, or
3756   //
3757   // - might cause an fopen in the subprocess to fail on a system
3758   //   suffering from bug 1085341.
3759   //
3760   // (Yes, the default setting of the close-on-exec flag is a Unix
3761   // design flaw.)
3762   //
3763   // See:
3764   // 1085341: 32-bit stdio routines should support file descriptors >255
3765   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3766   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3767 #ifdef FD_CLOEXEC
3768   {
3769     int flags = ::fcntl(fd, F_GETFD);
3770     if (flags != -1)
3771       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3772   }
3773 #endif
3774 
3775   return fd;
3776 }
3777 
3778 // create binary file, rewriting existing file if required
3779 int os::create_binary_file(const char* path, bool rewrite_existing) {
3780   int oflags = O_WRONLY | O_CREAT;
3781   if (!rewrite_existing) {
3782     oflags |= O_EXCL;
3783   }
3784   return ::open64(path, oflags, S_IREAD | S_IWRITE);
3785 }
3786 
3787 // return current position of file pointer
3788 jlong os::current_file_offset(int fd) {
3789   return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
3790 }
3791 
3792 // move file pointer to the specified offset
3793 jlong os::seek_to_file_offset(int fd, jlong offset) {
3794   return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
3795 }
3796 
3797 // This code originates from JDK's sysAvailable
3798 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3799 
3800 int os::available(int fd, jlong *bytes) {
3801   jlong cur, end;
3802   int mode;
3803   struct stat64 buf64;
3804 
3805   if (::fstat64(fd, &buf64) >= 0) {
3806     mode = buf64.st_mode;
3807     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3808       int n;
3809       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3810         *bytes = n;
3811         return 1;
3812       }
3813     }
3814   }
3815   if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
3816     return 0;
3817   } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
3818     return 0;
3819   } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
3820     return 0;
3821   }
3822   *bytes = end - cur;
3823   return 1;
3824 }
3825 
3826 // Map a block of memory.
3827 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3828                         char *addr, size_t bytes, bool read_only,
3829                         bool allow_exec) {
3830   int prot;
3831   int flags = MAP_PRIVATE;
3832 
3833   if (read_only) {
3834     prot = PROT_READ;
3835     flags = MAP_SHARED;
3836   } else {
3837     prot = PROT_READ | PROT_WRITE;
3838     flags = MAP_PRIVATE;
3839   }
3840 
3841   if (allow_exec) {
3842     prot |= PROT_EXEC;
3843   }
3844 
3845   if (addr != NULL) {
3846     flags |= MAP_FIXED;
3847   }
3848 
3849   // Allow anonymous mappings if 'fd' is -1.
3850   if (fd == -1) {
3851     flags |= MAP_ANONYMOUS;
3852   }
3853 
3854   char* mapped_address = (char*)::mmap(addr, (size_t)bytes, prot, flags,
3855                                      fd, file_offset);
3856   if (mapped_address == MAP_FAILED) {
3857     return NULL;
3858   }
3859   return mapped_address;
3860 }
3861 
3862 // Remap a block of memory.
3863 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3864                           char *addr, size_t bytes, bool read_only,
3865                           bool allow_exec) {
3866   // same as map_memory() on this OS
3867   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3868                         allow_exec);
3869 }
3870 
3871 // Unmap a block of memory.
3872 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3873   return munmap(addr, bytes) == 0;
3874 }
3875 
3876 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3877 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3878 // of a thread.
3879 //
3880 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3881 // the fast estimate available on the platform.
3882 
3883 jlong os::current_thread_cpu_time() {
3884   // return user + sys since the cost is the same
3885   const jlong n = os::thread_cpu_time(Thread::current(), true /* user + sys */);
3886   assert(n >= 0, "negative CPU time");
3887   return n;
3888 }
3889 
3890 jlong os::thread_cpu_time(Thread* thread) {
3891   // consistent with what current_thread_cpu_time() returns
3892   const jlong n = os::thread_cpu_time(thread, true /* user + sys */);
3893   assert(n >= 0, "negative CPU time");
3894   return n;
3895 }
3896 
3897 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3898   const jlong n = os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3899   assert(n >= 0, "negative CPU time");
3900   return n;
3901 }
3902 
3903 static bool thread_cpu_time_unchecked(Thread* thread, jlong* p_sys_time, jlong* p_user_time) {
3904   bool error = false;
3905 
3906   jlong sys_time = 0;
3907   jlong user_time = 0;
3908 
3909   // Reimplemented using getthrds64().
3910   //
3911   // Works like this:
3912   // For the thread in question, get the kernel thread id. Then get the
3913   // kernel thread statistics using that id.
3914   //
3915   // This only works of course when no pthread scheduling is used,
3916   // i.e. there is a 1:1 relationship to kernel threads.
3917   // On AIX, see AIXTHREAD_SCOPE variable.
3918 
3919   pthread_t pthtid = thread->osthread()->pthread_id();
3920 
3921   // retrieve kernel thread id for the pthread:
3922   tid64_t tid = 0;
3923   struct __pthrdsinfo pinfo;
3924   // I just love those otherworldly IBM APIs which force me to hand down
3925   // dummy buffers for stuff I dont care for...
3926   char dummy[1];
3927   int dummy_size = sizeof(dummy);
3928   if (pthread_getthrds_np(&pthtid, PTHRDSINFO_QUERY_TID, &pinfo, sizeof(pinfo),
3929                           dummy, &dummy_size) == 0) {
3930     tid = pinfo.__pi_tid;
3931   } else {
3932     tty->print_cr("pthread_getthrds_np failed.");
3933     error = true;
3934   }
3935 
3936   // retrieve kernel timing info for that kernel thread
3937   if (!error) {
3938     struct thrdentry64 thrdentry;
3939     if (getthrds64(getpid(), &thrdentry, sizeof(thrdentry), &tid, 1) == 1) {
3940       sys_time = thrdentry.ti_ru.ru_stime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_stime.tv_usec * 1000LL;
3941       user_time = thrdentry.ti_ru.ru_utime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_utime.tv_usec * 1000LL;
3942     } else {
3943       tty->print_cr("pthread_getthrds_np failed.");
3944       error = true;
3945     }
3946   }
3947 
3948   if (p_sys_time) {
3949     *p_sys_time = sys_time;
3950   }
3951 
3952   if (p_user_time) {
3953     *p_user_time = user_time;
3954   }
3955 
3956   if (error) {
3957     return false;
3958   }
3959 
3960   return true;
3961 }
3962 
3963 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3964   jlong sys_time;
3965   jlong user_time;
3966 
3967   if (!thread_cpu_time_unchecked(thread, &sys_time, &user_time)) {
3968     return -1;
3969   }
3970 
3971   return user_sys_cpu_time ? sys_time + user_time : user_time;
3972 }
3973 
3974 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3975   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3976   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3977   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3978   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3979 }
3980 
3981 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3982   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3983   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3984   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3985   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3986 }
3987 
3988 bool os::is_thread_cpu_time_supported() {
3989   return true;
3990 }
3991 
3992 // System loadavg support. Returns -1 if load average cannot be obtained.
3993 // For now just return the system wide load average (no processor sets).
3994 int os::loadavg(double values[], int nelem) {
3995 
3996   guarantee(nelem >= 0 && nelem <= 3, "argument error");
3997   guarantee(values, "argument error");
3998 
3999   if (os::Aix::on_pase()) {
4000 
4001     // AS/400 PASE: use libo4 porting library
4002     double v[3] = { 0.0, 0.0, 0.0 };
4003 
4004     if (libo4::get_load_avg(v, v + 1, v + 2)) {
4005       for (int i = 0; i < nelem; i ++) {
4006         values[i] = v[i];
4007       }
4008       return nelem;
4009     } else {
4010       return -1;
4011     }
4012 
4013   } else {
4014 
4015     // AIX: use libperfstat
4016     libperfstat::cpuinfo_t ci;
4017     if (libperfstat::get_cpuinfo(&ci)) {
4018       for (int i = 0; i < nelem; i++) {
4019         values[i] = ci.loadavg[i];
4020       }
4021     } else {
4022       return -1;
4023     }
4024     return nelem;
4025   }
4026 }
4027 
4028 void os::pause() {
4029   char filename[MAX_PATH];
4030   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4031     jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
4032   } else {
4033     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4034   }
4035 
4036   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4037   if (fd != -1) {
4038     struct stat buf;
4039     ::close(fd);
4040     while (::stat(filename, &buf) == 0) {
4041       (void)::poll(NULL, 0, 100);
4042     }
4043   } else {
4044     trcVerbose("Could not open pause file '%s', continuing immediately.", filename);
4045   }
4046 }
4047 
4048 bool os::is_primordial_thread(void) {
4049   if (pthread_self() == (pthread_t)1) {
4050     return true;
4051   } else {
4052     return false;
4053   }
4054 }
4055 
4056 // OS recognitions (PASE/AIX, OS level) call this before calling any
4057 // one of Aix::on_pase(), Aix::os_version() static
4058 void os::Aix::initialize_os_info() {
4059 
4060   assert(_on_pase == -1 && _os_version == 0, "already called.");
4061 
4062   struct utsname uts;
4063   memset(&uts, 0, sizeof(uts));
4064   strcpy(uts.sysname, "?");
4065   if (::uname(&uts) == -1) {
4066     trcVerbose("uname failed (%d)", errno);
4067     guarantee(0, "Could not determine whether we run on AIX or PASE");
4068   } else {
4069     trcVerbose("uname says: sysname \"%s\" version \"%s\" release \"%s\" "
4070                "node \"%s\" machine \"%s\"\n",
4071                uts.sysname, uts.version, uts.release, uts.nodename, uts.machine);
4072     const int major = atoi(uts.version);
4073     assert(major > 0, "invalid OS version");
4074     const int minor = atoi(uts.release);
4075     assert(minor > 0, "invalid OS release");
4076     _os_version = (major << 24) | (minor << 16);
4077     char ver_str[20] = {0};
4078     const char* name_str = "unknown OS";
4079     if (strcmp(uts.sysname, "OS400") == 0) {
4080       // We run on AS/400 PASE. We do not support versions older than V5R4M0.
4081       _on_pase = 1;
4082       if (os_version_short() < 0x0504) {
4083         trcVerbose("OS/400 releases older than V5R4M0 not supported.");
4084         assert(false, "OS/400 release too old.");
4085       }
4086       name_str = "OS/400 (pase)";
4087       jio_snprintf(ver_str, sizeof(ver_str), "%u.%u", major, minor);
4088     } else if (strcmp(uts.sysname, "AIX") == 0) {
4089       // We run on AIX. We do not support versions older than AIX 7.1.
4090       _on_pase = 0;
4091       // Determine detailed AIX version: Version, Release, Modification, Fix Level.
4092       odmWrapper::determine_os_kernel_version(&_os_version);
4093       if (os_version_short() < 0x0701) {
4094         trcVerbose("AIX releases older than AIX 7.1 are not supported.");
4095         assert(false, "AIX release too old.");
4096       }
4097       name_str = "AIX";
4098       jio_snprintf(ver_str, sizeof(ver_str), "%u.%u.%u.%u",
4099                    major, minor, (_os_version >> 8) & 0xFF, _os_version & 0xFF);
4100     } else {
4101       assert(false, "%s", name_str);
4102     }
4103     trcVerbose("We run on %s %s", name_str, ver_str);
4104   }
4105 
4106   guarantee(_on_pase != -1 && _os_version, "Could not determine AIX/OS400 release");
4107 } // end: os::Aix::initialize_os_info()
4108 
4109 // Scan environment for important settings which might effect the VM.
4110 // Trace out settings. Warn about invalid settings and/or correct them.
4111 //
4112 // Must run after os::Aix::initialue_os_info().
4113 void os::Aix::scan_environment() {
4114 
4115   char* p;
4116   int rc;
4117 
4118   // Warn explicity if EXTSHM=ON is used. That switch changes how
4119   // System V shared memory behaves. One effect is that page size of
4120   // shared memory cannot be change dynamically, effectivly preventing
4121   // large pages from working.
4122   // This switch was needed on AIX 32bit, but on AIX 64bit the general
4123   // recommendation is (in OSS notes) to switch it off.
4124   p = ::getenv("EXTSHM");
4125   trcVerbose("EXTSHM=%s.", p ? p : "<unset>");
4126   if (p && strcasecmp(p, "ON") == 0) {
4127     _extshm = 1;
4128     trcVerbose("*** Unsupported mode! Please remove EXTSHM from your environment! ***");
4129     if (!AllowExtshm) {
4130       // We allow under certain conditions the user to continue. However, we want this
4131       // to be a fatal error by default. On certain AIX systems, leaving EXTSHM=ON means
4132       // that the VM is not able to allocate 64k pages for the heap.
4133       // We do not want to run with reduced performance.
4134       vm_exit_during_initialization("EXTSHM is ON. Please remove EXTSHM from your environment.");
4135     }
4136   } else {
4137     _extshm = 0;
4138   }
4139 
4140   // SPEC1170 behaviour: will change the behaviour of a number of POSIX APIs.
4141   // Not tested, not supported.
4142   //
4143   // Note that it might be worth the trouble to test and to require it, if only to
4144   // get useful return codes for mprotect.
4145   //
4146   // Note: Setting XPG_SUS_ENV in the process is too late. Must be set earlier (before
4147   // exec() ? before loading the libjvm ? ....)
4148   p = ::getenv("XPG_SUS_ENV");
4149   trcVerbose("XPG_SUS_ENV=%s.", p ? p : "<unset>");
4150   if (p && strcmp(p, "ON") == 0) {
4151     _xpg_sus_mode = 1;
4152     trcVerbose("Unsupported setting: XPG_SUS_ENV=ON");
4153     // This is not supported. Worst of all, it changes behaviour of mmap MAP_FIXED to
4154     // clobber address ranges. If we ever want to support that, we have to do some
4155     // testing first.
4156     guarantee(false, "XPG_SUS_ENV=ON not supported");
4157   } else {
4158     _xpg_sus_mode = 0;
4159   }
4160 
4161   if (os::Aix::on_pase()) {
4162     p = ::getenv("QIBM_MULTI_THREADED");
4163     trcVerbose("QIBM_MULTI_THREADED=%s.", p ? p : "<unset>");
4164   }
4165 
4166   p = ::getenv("LDR_CNTRL");
4167   trcVerbose("LDR_CNTRL=%s.", p ? p : "<unset>");
4168   if (os::Aix::on_pase() && os::Aix::os_version_short() == 0x0701) {
4169     if (p && ::strstr(p, "TEXTPSIZE")) {
4170       trcVerbose("*** WARNING - LDR_CNTRL contains TEXTPSIZE. "
4171         "you may experience hangs or crashes on OS/400 V7R1.");
4172     }
4173   }
4174 
4175   p = ::getenv("AIXTHREAD_GUARDPAGES");
4176   trcVerbose("AIXTHREAD_GUARDPAGES=%s.", p ? p : "<unset>");
4177 
4178 } // end: os::Aix::scan_environment()
4179 
4180 // PASE: initialize the libo4 library (PASE porting library).
4181 void os::Aix::initialize_libo4() {
4182   guarantee(os::Aix::on_pase(), "OS/400 only.");
4183   if (!libo4::init()) {
4184     trcVerbose("libo4 initialization failed.");
4185     assert(false, "libo4 initialization failed");
4186   } else {
4187     trcVerbose("libo4 initialized.");
4188   }
4189 }
4190 
4191 // AIX: initialize the libperfstat library.
4192 void os::Aix::initialize_libperfstat() {
4193   assert(os::Aix::on_aix(), "AIX only");
4194   if (!libperfstat::init()) {
4195     trcVerbose("libperfstat initialization failed.");
4196     assert(false, "libperfstat initialization failed");
4197   } else {
4198     trcVerbose("libperfstat initialized.");
4199   }
4200 }
4201 
4202 /////////////////////////////////////////////////////////////////////////////
4203 // thread stack
4204 
4205 // Get the current stack base from the OS (actually, the pthread library).
4206 // Note: usually not page aligned.
4207 address os::current_stack_base() {
4208   AixMisc::stackbounds_t bounds;
4209   bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
4210   guarantee(rc, "Unable to retrieve stack bounds.");
4211   return bounds.base;
4212 }
4213 
4214 // Get the current stack size from the OS (actually, the pthread library).
4215 // Returned size is such that (base - size) is always aligned to page size.
4216 size_t os::current_stack_size() {
4217   AixMisc::stackbounds_t bounds;
4218   bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
4219   guarantee(rc, "Unable to retrieve stack bounds.");
4220   // Align the returned stack size such that the stack low address
4221   // is aligned to page size (Note: base is usually not and we do not care).
4222   // We need to do this because caller code will assume stack low address is
4223   // page aligned and will place guard pages without checking.
4224   address low = bounds.base - bounds.size;
4225   address low_aligned = (address)align_up(low, os::vm_page_size());
4226   size_t s = bounds.base - low_aligned;
4227   return s;
4228 }
4229 
4230 extern char** environ;
4231 
4232 // Run the specified command in a separate process. Return its exit value,
4233 // or -1 on failure (e.g. can't fork a new process).
4234 // Unlike system(), this function can be called from signal handler. It
4235 // doesn't block SIGINT et al.
4236 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
4237   char* argv[4] = { (char*)"sh", (char*)"-c", cmd, NULL};
4238 
4239   pid_t pid = fork();
4240 
4241   if (pid < 0) {
4242     // fork failed
4243     return -1;
4244 
4245   } else if (pid == 0) {
4246     // child process
4247 
4248     // Try to be consistent with system(), which uses "/usr/bin/sh" on AIX.
4249     execve("/usr/bin/sh", argv, environ);
4250 
4251     // execve failed
4252     _exit(-1);
4253 
4254   } else {
4255     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4256     // care about the actual exit code, for now.
4257 
4258     int status;
4259 
4260     // Wait for the child process to exit. This returns immediately if
4261     // the child has already exited. */
4262     while (waitpid(pid, &status, 0) < 0) {
4263       switch (errno) {
4264         case ECHILD: return 0;
4265         case EINTR: break;
4266         default: return -1;
4267       }
4268     }
4269 
4270     if (WIFEXITED(status)) {
4271       // The child exited normally; get its exit code.
4272       return WEXITSTATUS(status);
4273     } else if (WIFSIGNALED(status)) {
4274       // The child exited because of a signal.
4275       // The best value to return is 0x80 + signal number,
4276       // because that is what all Unix shells do, and because
4277       // it allows callers to distinguish between process exit and
4278       // process death by signal.
4279       return 0x80 + WTERMSIG(status);
4280     } else {
4281       // Unknown exit code; pass it through.
4282       return status;
4283     }
4284   }
4285   return -1;
4286 }
4287 
4288 // Get the default path to the core file
4289 // Returns the length of the string
4290 int os::get_core_path(char* buffer, size_t bufferSize) {
4291   const char* p = get_current_directory(buffer, bufferSize);
4292 
4293   if (p == NULL) {
4294     assert(p != NULL, "failed to get current directory");
4295     return 0;
4296   }
4297 
4298   jio_snprintf(buffer, bufferSize, "%s/core or core.%d",
4299                                                p, current_process_id());
4300 
4301   return strlen(buffer);
4302 }
4303 
4304 #ifndef PRODUCT
4305 void TestReserveMemorySpecial_test() {
4306   // No tests available for this platform
4307 }
4308 #endif
4309 
4310 bool os::start_debugging(char *buf, int buflen) {
4311   int len = (int)strlen(buf);
4312   char *p = &buf[len];
4313 
4314   jio_snprintf(p, buflen -len,
4315                  "\n\n"
4316                  "Do you want to debug the problem?\n\n"
4317                  "To debug, run 'dbx -a %d'; then switch to thread tid " INTX_FORMAT ", k-tid " INTX_FORMAT "\n"
4318                  "Enter 'yes' to launch dbx automatically (PATH must include dbx)\n"
4319                  "Otherwise, press RETURN to abort...",
4320                  os::current_process_id(),
4321                  os::current_thread_id(), thread_self());
4322 
4323   bool yes = os::message_box("Unexpected Error", buf);
4324 
4325   if (yes) {
4326     // yes, user asked VM to launch debugger
4327     jio_snprintf(buf, buflen, "dbx -a %d", os::current_process_id());
4328 
4329     os::fork_and_exec(buf);
4330     yes = false;
4331   }
4332   return yes;
4333 }
4334 
4335 static inline time_t get_mtime(const char* filename) {
4336   struct stat st;
4337   int ret = os::stat(filename, &st);
4338   assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
4339   return st.st_mtime;
4340 }
4341 
4342 int os::compare_file_modified_times(const char* file1, const char* file2) {
4343   time_t t1 = get_mtime(file1);
4344   time_t t2 = get_mtime(file2);
4345   return t1 - t2;
4346 }
4347 
4348 bool os::supports_map_sync() {
4349   return false;
4350 }