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_rlimit_info(st);
1389 
1390   os::Posix::print_load_average(st);
1391 
1392   // _SC_THREAD_THREADS_MAX is the maximum number of threads within a process.
1393   long tmax = sysconf(_SC_THREAD_THREADS_MAX);
1394   st->print_cr("maximum #threads within a process:%ld", tmax);
1395 
1396   // print wpar info
1397   libperfstat::wparinfo_t wi;
1398   if (libperfstat::get_wparinfo(&wi)) {
1399     st->print_cr("wpar info");
1400     st->print_cr("name: %s", wi.name);
1401     st->print_cr("id:   %d", wi.wpar_id);
1402     st->print_cr("type: %s", (wi.app_wpar ? "application" : "system"));
1403   }
1404 
1405   VM_Version::print_platform_virtualization_info(st);
1406 }
1407 
1408 void os::print_memory_info(outputStream* st) {
1409 
1410   st->print_cr("Memory:");
1411 
1412   st->print_cr("  Base page size (sysconf _SC_PAGESIZE):  %s",
1413     describe_pagesize(g_multipage_support.pagesize));
1414   st->print_cr("  Data page size (C-Heap, bss, etc):      %s",
1415     describe_pagesize(g_multipage_support.datapsize));
1416   st->print_cr("  Text page size:                         %s",
1417     describe_pagesize(g_multipage_support.textpsize));
1418   st->print_cr("  Thread stack page size (pthread):       %s",
1419     describe_pagesize(g_multipage_support.pthr_stack_pagesize));
1420   st->print_cr("  Default shared memory page size:        %s",
1421     describe_pagesize(g_multipage_support.shmpsize));
1422   st->print_cr("  Can use 64K pages dynamically with shared memory:  %s",
1423     (g_multipage_support.can_use_64K_pages ? "yes" :"no"));
1424   st->print_cr("  Can use 16M pages dynamically with shared memory: %s",
1425     (g_multipage_support.can_use_16M_pages ? "yes" :"no"));
1426   st->print_cr("  Multipage error: %d",
1427     g_multipage_support.error);
1428   st->cr();
1429   st->print_cr("  os::vm_page_size:       %s", describe_pagesize(os::vm_page_size()));
1430 
1431   // print out LDR_CNTRL because it affects the default page sizes
1432   const char* const ldr_cntrl = ::getenv("LDR_CNTRL");
1433   st->print_cr("  LDR_CNTRL=%s.", ldr_cntrl ? ldr_cntrl : "<unset>");
1434 
1435   // Print out EXTSHM because it is an unsupported setting.
1436   const char* const extshm = ::getenv("EXTSHM");
1437   st->print_cr("  EXTSHM=%s.", extshm ? extshm : "<unset>");
1438   if ( (strcmp(extshm, "on") == 0) || (strcmp(extshm, "ON") == 0) ) {
1439     st->print_cr("  *** Unsupported! Please remove EXTSHM from your environment! ***");
1440   }
1441 
1442   // Print out AIXTHREAD_GUARDPAGES because it affects the size of pthread stacks.
1443   const char* const aixthread_guardpages = ::getenv("AIXTHREAD_GUARDPAGES");
1444   st->print_cr("  AIXTHREAD_GUARDPAGES=%s.",
1445       aixthread_guardpages ? aixthread_guardpages : "<unset>");
1446   st->cr();
1447 
1448   os::Aix::meminfo_t mi;
1449   if (os::Aix::get_meminfo(&mi)) {
1450     if (os::Aix::on_aix()) {
1451       st->print_cr("physical total : " SIZE_FORMAT, mi.real_total);
1452       st->print_cr("physical free  : " SIZE_FORMAT, mi.real_free);
1453       st->print_cr("swap total     : " SIZE_FORMAT, mi.pgsp_total);
1454       st->print_cr("swap free      : " SIZE_FORMAT, mi.pgsp_free);
1455     } else {
1456       // PASE - Numbers are result of QWCRSSTS; they mean:
1457       // real_total: Sum of all system pools
1458       // real_free: always 0
1459       // pgsp_total: we take the size of the system ASP
1460       // pgsp_free: size of system ASP times percentage of system ASP unused
1461       st->print_cr("physical total     : " SIZE_FORMAT, mi.real_total);
1462       st->print_cr("system asp total   : " SIZE_FORMAT, mi.pgsp_total);
1463       st->print_cr("%% system asp used : %.2f",
1464         mi.pgsp_total ? (100.0f * (mi.pgsp_total - mi.pgsp_free) / mi.pgsp_total) : -1.0f);
1465     }
1466   }
1467   st->cr();
1468 
1469   // Print program break.
1470   st->print_cr("Program break at VM startup: " PTR_FORMAT ".", p2i(g_brk_at_startup));
1471   address brk_now = (address)::sbrk(0);
1472   if (brk_now != (address)-1) {
1473     st->print_cr("Program break now          : " PTR_FORMAT " (distance: " SIZE_FORMAT "k).",
1474                  p2i(brk_now), (size_t)((brk_now - g_brk_at_startup) / K));
1475   }
1476   st->print_cr("MaxExpectedDataSegmentSize    : " SIZE_FORMAT "k.", MaxExpectedDataSegmentSize / K);
1477   st->cr();
1478 
1479   // Print segments allocated with os::reserve_memory.
1480   st->print_cr("internal virtual memory regions used by vm:");
1481   vmembk_print_on(st);
1482 }
1483 
1484 // Get a string for the cpuinfo that is a summary of the cpu type
1485 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1486   // read _system_configuration.version
1487   switch (_system_configuration.version) {
1488   case PV_9:
1489     strncpy(buf, "Power PC 9", buflen);
1490     break;
1491   case PV_8:
1492     strncpy(buf, "Power PC 8", buflen);
1493     break;
1494   case PV_7:
1495     strncpy(buf, "Power PC 7", buflen);
1496     break;
1497   case PV_6_1:
1498     strncpy(buf, "Power PC 6 DD1.x", buflen);
1499     break;
1500   case PV_6:
1501     strncpy(buf, "Power PC 6", buflen);
1502     break;
1503   case PV_5:
1504     strncpy(buf, "Power PC 5", buflen);
1505     break;
1506   case PV_5_2:
1507     strncpy(buf, "Power PC 5_2", buflen);
1508     break;
1509   case PV_5_3:
1510     strncpy(buf, "Power PC 5_3", buflen);
1511     break;
1512   case PV_5_Compat:
1513     strncpy(buf, "PV_5_Compat", buflen);
1514     break;
1515   case PV_6_Compat:
1516     strncpy(buf, "PV_6_Compat", buflen);
1517     break;
1518   case PV_7_Compat:
1519     strncpy(buf, "PV_7_Compat", buflen);
1520     break;
1521   case PV_8_Compat:
1522     strncpy(buf, "PV_8_Compat", buflen);
1523     break;
1524   case PV_9_Compat:
1525     strncpy(buf, "PV_9_Compat", buflen);
1526     break;
1527   default:
1528     strncpy(buf, "unknown", buflen);
1529   }
1530 }
1531 
1532 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1533   // Nothing to do beyond of what os::print_cpu_info() does.
1534 }
1535 
1536 static void print_signal_handler(outputStream* st, int sig,
1537                                  char* buf, size_t buflen);
1538 
1539 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1540   st->print_cr("Signal Handlers:");
1541   print_signal_handler(st, SIGSEGV, buf, buflen);
1542   print_signal_handler(st, SIGBUS , buf, buflen);
1543   print_signal_handler(st, SIGFPE , buf, buflen);
1544   print_signal_handler(st, SIGPIPE, buf, buflen);
1545   print_signal_handler(st, SIGXFSZ, buf, buflen);
1546   print_signal_handler(st, SIGILL , buf, buflen);
1547   print_signal_handler(st, SR_signum, buf, buflen);
1548   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1549   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1550   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1551   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1552   print_signal_handler(st, SIGTRAP, buf, buflen);
1553   // We also want to know if someone else adds a SIGDANGER handler because
1554   // that will interfere with OOM killling.
1555   print_signal_handler(st, SIGDANGER, buf, buflen);
1556 }
1557 
1558 static char saved_jvm_path[MAXPATHLEN] = {0};
1559 
1560 // Find the full path to the current module, libjvm.so.
1561 void os::jvm_path(char *buf, jint buflen) {
1562   // Error checking.
1563   if (buflen < MAXPATHLEN) {
1564     assert(false, "must use a large-enough buffer");
1565     buf[0] = '\0';
1566     return;
1567   }
1568   // Lazy resolve the path to current module.
1569   if (saved_jvm_path[0] != 0) {
1570     strcpy(buf, saved_jvm_path);
1571     return;
1572   }
1573 
1574   Dl_info dlinfo;
1575   int ret = dladdr(CAST_FROM_FN_PTR(void *, os::jvm_path), &dlinfo);
1576   assert(ret != 0, "cannot locate libjvm");
1577   char* rp = os::Posix::realpath((char *)dlinfo.dli_fname, buf, buflen);
1578   assert(rp != NULL, "error in realpath(): maybe the 'path' argument is too long?");
1579 
1580   if (Arguments::sun_java_launcher_is_altjvm()) {
1581     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1582     // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
1583     // If "/jre/lib/" appears at the right place in the string, then
1584     // assume we are installed in a JDK and we're done. Otherwise, check
1585     // for a JAVA_HOME environment variable and fix up the path so it
1586     // looks like libjvm.so is installed there (append a fake suffix
1587     // hotspot/libjvm.so).
1588     const char *p = buf + strlen(buf) - 1;
1589     for (int count = 0; p > buf && count < 4; ++count) {
1590       for (--p; p > buf && *p != '/'; --p)
1591         /* empty */ ;
1592     }
1593 
1594     if (strncmp(p, "/jre/lib/", 9) != 0) {
1595       // Look for JAVA_HOME in the environment.
1596       char* java_home_var = ::getenv("JAVA_HOME");
1597       if (java_home_var != NULL && java_home_var[0] != 0) {
1598         char* jrelib_p;
1599         int len;
1600 
1601         // Check the current module name "libjvm.so".
1602         p = strrchr(buf, '/');
1603         if (p == NULL) {
1604           return;
1605         }
1606         assert(strstr(p, "/libjvm") == p, "invalid library name");
1607 
1608         rp = os::Posix::realpath(java_home_var, buf, buflen);
1609         if (rp == NULL) {
1610           return;
1611         }
1612 
1613         // determine if this is a legacy image or modules image
1614         // modules image doesn't have "jre" subdirectory
1615         len = strlen(buf);
1616         assert(len < buflen, "Ran out of buffer room");
1617         jrelib_p = buf + len;
1618         snprintf(jrelib_p, buflen-len, "/jre/lib");
1619         if (0 != access(buf, F_OK)) {
1620           snprintf(jrelib_p, buflen-len, "/lib");
1621         }
1622 
1623         if (0 == access(buf, F_OK)) {
1624           // Use current module name "libjvm.so"
1625           len = strlen(buf);
1626           snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
1627         } else {
1628           // Go back to path of .so
1629           rp = os::Posix::realpath((char *)dlinfo.dli_fname, buf, buflen);
1630           if (rp == NULL) {
1631             return;
1632           }
1633         }
1634       }
1635     }
1636   }
1637 
1638   strncpy(saved_jvm_path, buf, sizeof(saved_jvm_path));
1639   saved_jvm_path[sizeof(saved_jvm_path) - 1] = '\0';
1640 }
1641 
1642 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1643   // no prefix required, not even "_"
1644 }
1645 
1646 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1647   // no suffix required
1648 }
1649 
1650 ////////////////////////////////////////////////////////////////////////////////
1651 // sun.misc.Signal support
1652 
1653 static void
1654 UserHandler(int sig, void *siginfo, void *context) {
1655   // Ctrl-C is pressed during error reporting, likely because the error
1656   // handler fails to abort. Let VM die immediately.
1657   if (sig == SIGINT && VMError::is_error_reported()) {
1658     os::die();
1659   }
1660 
1661   os::signal_notify(sig);
1662 }
1663 
1664 void* os::user_handler() {
1665   return CAST_FROM_FN_PTR(void*, UserHandler);
1666 }
1667 
1668 extern "C" {
1669   typedef void (*sa_handler_t)(int);
1670   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1671 }
1672 
1673 void* os::signal(int signal_number, void* handler) {
1674   struct sigaction sigAct, oldSigAct;
1675 
1676   sigfillset(&(sigAct.sa_mask));
1677 
1678   // Do not block out synchronous signals in the signal handler.
1679   // Blocking synchronous signals only makes sense if you can really
1680   // be sure that those signals won't happen during signal handling,
1681   // when the blocking applies. Normal signal handlers are lean and
1682   // do not cause signals. But our signal handlers tend to be "risky"
1683   // - secondary SIGSEGV, SIGILL, SIGBUS' may and do happen.
1684   // On AIX, PASE there was a case where a SIGSEGV happened, followed
1685   // by a SIGILL, which was blocked due to the signal mask. The process
1686   // just hung forever. Better to crash from a secondary signal than to hang.
1687   sigdelset(&(sigAct.sa_mask), SIGSEGV);
1688   sigdelset(&(sigAct.sa_mask), SIGBUS);
1689   sigdelset(&(sigAct.sa_mask), SIGILL);
1690   sigdelset(&(sigAct.sa_mask), SIGFPE);
1691   sigdelset(&(sigAct.sa_mask), SIGTRAP);
1692 
1693   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1694 
1695   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1696 
1697   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1698     // -1 means registration failed
1699     return (void *)-1;
1700   }
1701 
1702   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1703 }
1704 
1705 void os::signal_raise(int signal_number) {
1706   ::raise(signal_number);
1707 }
1708 
1709 //
1710 // The following code is moved from os.cpp for making this
1711 // code platform specific, which it is by its very nature.
1712 //
1713 
1714 // Will be modified when max signal is changed to be dynamic
1715 int os::sigexitnum_pd() {
1716   return NSIG;
1717 }
1718 
1719 // a counter for each possible signal value
1720 static volatile jint pending_signals[NSIG+1] = { 0 };
1721 
1722 // Wrapper functions for: sem_init(), sem_post(), sem_wait()
1723 // On AIX, we use sem_init(), sem_post(), sem_wait()
1724 // On Pase, we need to use msem_lock() and msem_unlock(), because Posix Semaphores
1725 // do not seem to work at all on PASE (unimplemented, will cause SIGILL).
1726 // Note that just using msem_.. APIs for both PASE and AIX is not an option either, as
1727 // on AIX, msem_..() calls are suspected of causing problems.
1728 static sem_t sig_sem;
1729 static msemaphore* p_sig_msem = 0;
1730 
1731 static void local_sem_init() {
1732   if (os::Aix::on_aix()) {
1733     int rc = ::sem_init(&sig_sem, 0, 0);
1734     guarantee(rc != -1, "sem_init failed");
1735   } else {
1736     // Memory semaphores must live in shared mem.
1737     guarantee0(p_sig_msem == NULL);
1738     p_sig_msem = (msemaphore*)os::reserve_memory(sizeof(msemaphore), NULL);
1739     guarantee(p_sig_msem, "Cannot allocate memory for memory semaphore");
1740     guarantee(::msem_init(p_sig_msem, 0) == p_sig_msem, "msem_init failed");
1741   }
1742 }
1743 
1744 static void local_sem_post() {
1745   static bool warn_only_once = false;
1746   if (os::Aix::on_aix()) {
1747     int rc = ::sem_post(&sig_sem);
1748     if (rc == -1 && !warn_only_once) {
1749       trcVerbose("sem_post failed (errno = %d, %s)", errno, os::errno_name(errno));
1750       warn_only_once = true;
1751     }
1752   } else {
1753     guarantee0(p_sig_msem != NULL);
1754     int rc = ::msem_unlock(p_sig_msem, 0);
1755     if (rc == -1 && !warn_only_once) {
1756       trcVerbose("msem_unlock failed (errno = %d, %s)", errno, os::errno_name(errno));
1757       warn_only_once = true;
1758     }
1759   }
1760 }
1761 
1762 static void local_sem_wait() {
1763   static bool warn_only_once = false;
1764   if (os::Aix::on_aix()) {
1765     int rc = ::sem_wait(&sig_sem);
1766     if (rc == -1 && !warn_only_once) {
1767       trcVerbose("sem_wait failed (errno = %d, %s)", errno, os::errno_name(errno));
1768       warn_only_once = true;
1769     }
1770   } else {
1771     guarantee0(p_sig_msem != NULL); // must init before use
1772     int rc = ::msem_lock(p_sig_msem, 0);
1773     if (rc == -1 && !warn_only_once) {
1774       trcVerbose("msem_lock failed (errno = %d, %s)", errno, os::errno_name(errno));
1775       warn_only_once = true;
1776     }
1777   }
1778 }
1779 
1780 static void jdk_misc_signal_init() {
1781   // Initialize signal structures
1782   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1783 
1784   // Initialize signal semaphore
1785   local_sem_init();
1786 }
1787 
1788 void os::signal_notify(int sig) {
1789   Atomic::inc(&pending_signals[sig]);
1790   local_sem_post();
1791 }
1792 
1793 static int check_pending_signals() {
1794   for (;;) {
1795     for (int i = 0; i < NSIG + 1; i++) {
1796       jint n = pending_signals[i];
1797       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1798         return i;
1799       }
1800     }
1801     JavaThread *thread = JavaThread::current();
1802     ThreadBlockInVM tbivm(thread);
1803 
1804     bool threadIsSuspended;
1805     do {
1806       thread->set_suspend_equivalent();
1807       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1808 
1809       local_sem_wait();
1810 
1811       // were we externally suspended while we were waiting?
1812       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1813       if (threadIsSuspended) {
1814         //
1815         // The semaphore has been incremented, but while we were waiting
1816         // another thread suspended us. We don't want to continue running
1817         // while suspended because that would surprise the thread that
1818         // suspended us.
1819         //
1820 
1821         local_sem_post();
1822 
1823         thread->java_suspend_self();
1824       }
1825     } while (threadIsSuspended);
1826   }
1827 }
1828 
1829 int os::signal_wait() {
1830   return check_pending_signals();
1831 }
1832 
1833 ////////////////////////////////////////////////////////////////////////////////
1834 // Virtual Memory
1835 
1836 // We need to keep small simple bookkeeping for os::reserve_memory and friends.
1837 
1838 #define VMEM_MAPPED  1
1839 #define VMEM_SHMATED 2
1840 
1841 struct vmembk_t {
1842   int type;         // 1 - mmap, 2 - shmat
1843   char* addr;
1844   size_t size;      // Real size, may be larger than usersize.
1845   size_t pagesize;  // page size of area
1846   vmembk_t* next;
1847 
1848   bool contains_addr(char* p) const {
1849     return p >= addr && p < (addr + size);
1850   }
1851 
1852   bool contains_range(char* p, size_t s) const {
1853     return contains_addr(p) && contains_addr(p + s - 1);
1854   }
1855 
1856   void print_on(outputStream* os) const {
1857     os->print("[" PTR_FORMAT " - " PTR_FORMAT "] (" UINTX_FORMAT
1858       " bytes, %d %s pages), %s",
1859       addr, addr + size - 1, size, size / pagesize, describe_pagesize(pagesize),
1860       (type == VMEM_SHMATED ? "shmat" : "mmap")
1861     );
1862   }
1863 
1864   // Check that range is a sub range of memory block (or equal to memory block);
1865   // also check that range is fully page aligned to the page size if the block.
1866   void assert_is_valid_subrange(char* p, size_t s) const {
1867     if (!contains_range(p, s)) {
1868       trcVerbose("[" PTR_FORMAT " - " PTR_FORMAT "] is not a sub "
1869               "range of [" PTR_FORMAT " - " PTR_FORMAT "].",
1870               p2i(p), p2i(p + s), p2i(addr), p2i(addr + size));
1871       guarantee0(false);
1872     }
1873     if (!is_aligned_to(p, pagesize) || !is_aligned_to(p + s, pagesize)) {
1874       trcVerbose("range [" PTR_FORMAT " - " PTR_FORMAT "] is not"
1875               " aligned to pagesize (%lu)", p2i(p), p2i(p + s), (unsigned long) pagesize);
1876       guarantee0(false);
1877     }
1878   }
1879 };
1880 
1881 static struct {
1882   vmembk_t* first;
1883   MiscUtils::CritSect cs;
1884 } vmem;
1885 
1886 static void vmembk_add(char* addr, size_t size, size_t pagesize, int type) {
1887   vmembk_t* p = (vmembk_t*) ::malloc(sizeof(vmembk_t));
1888   assert0(p);
1889   if (p) {
1890     MiscUtils::AutoCritSect lck(&vmem.cs);
1891     p->addr = addr; p->size = size;
1892     p->pagesize = pagesize;
1893     p->type = type;
1894     p->next = vmem.first;
1895     vmem.first = p;
1896   }
1897 }
1898 
1899 static vmembk_t* vmembk_find(char* addr) {
1900   MiscUtils::AutoCritSect lck(&vmem.cs);
1901   for (vmembk_t* p = vmem.first; p; p = p->next) {
1902     if (p->addr <= addr && (p->addr + p->size) > addr) {
1903       return p;
1904     }
1905   }
1906   return NULL;
1907 }
1908 
1909 static void vmembk_remove(vmembk_t* p0) {
1910   MiscUtils::AutoCritSect lck(&vmem.cs);
1911   assert0(p0);
1912   assert0(vmem.first); // List should not be empty.
1913   for (vmembk_t** pp = &(vmem.first); *pp; pp = &((*pp)->next)) {
1914     if (*pp == p0) {
1915       *pp = p0->next;
1916       ::free(p0);
1917       return;
1918     }
1919   }
1920   assert0(false); // Not found?
1921 }
1922 
1923 static void vmembk_print_on(outputStream* os) {
1924   MiscUtils::AutoCritSect lck(&vmem.cs);
1925   for (vmembk_t* vmi = vmem.first; vmi; vmi = vmi->next) {
1926     vmi->print_on(os);
1927     os->cr();
1928   }
1929 }
1930 
1931 // Reserve and attach a section of System V memory.
1932 // If <requested_addr> is not NULL, function will attempt to attach the memory at the given
1933 // address. Failing that, it will attach the memory anywhere.
1934 // If <requested_addr> is NULL, function will attach the memory anywhere.
1935 //
1936 // <alignment_hint> is being ignored by this function. It is very probable however that the
1937 // alignment requirements are met anyway, because shmat() attaches at 256M boundaries.
1938 // Should this be not enogh, we can put more work into it.
1939 static char* reserve_shmated_memory (
1940   size_t bytes,
1941   char* requested_addr,
1942   size_t alignment_hint) {
1943 
1944   trcVerbose("reserve_shmated_memory " UINTX_FORMAT " bytes, wishaddress "
1945     PTR_FORMAT ", alignment_hint " UINTX_FORMAT "...",
1946     bytes, p2i(requested_addr), alignment_hint);
1947 
1948   // Either give me wish address or wish alignment but not both.
1949   assert0(!(requested_addr != NULL && alignment_hint != 0));
1950 
1951   // We must prevent anyone from attaching too close to the
1952   // BRK because that may cause malloc OOM.
1953   if (requested_addr != NULL && is_close_to_brk((address)requested_addr)) {
1954     trcVerbose("Wish address " PTR_FORMAT " is too close to the BRK segment. "
1955       "Will attach anywhere.", p2i(requested_addr));
1956     // Act like the OS refused to attach there.
1957     requested_addr = NULL;
1958   }
1959 
1960   // For old AS/400's (V5R4 and older) we should not even be here - System V shared memory is not
1961   // really supported (max size 4GB), so reserve_mmapped_memory should have been used instead.
1962   if (os::Aix::on_pase_V5R4_or_older()) {
1963     ShouldNotReachHere();
1964   }
1965 
1966   // Align size of shm up to 64K to avoid errors if we later try to change the page size.
1967   const size_t size = align_up(bytes, 64*K);
1968 
1969   // Reserve the shared segment.
1970   int shmid = shmget(IPC_PRIVATE, size, IPC_CREAT | S_IRUSR | S_IWUSR);
1971   if (shmid == -1) {
1972     trcVerbose("shmget(.., " UINTX_FORMAT ", ..) failed (errno: %d).", size, errno);
1973     return NULL;
1974   }
1975 
1976   // Important note:
1977   // It is very important that we, upon leaving this function, do not leave a shm segment alive.
1978   // We must right after attaching it remove it from the system. System V shm segments are global and
1979   // survive the process.
1980   // So, from here on: Do not assert, do not return, until we have called shmctl(IPC_RMID) (A).
1981 
1982   struct shmid_ds shmbuf;
1983   memset(&shmbuf, 0, sizeof(shmbuf));
1984   shmbuf.shm_pagesize = 64*K;
1985   if (shmctl(shmid, SHM_PAGESIZE, &shmbuf) != 0) {
1986     trcVerbose("Failed to set page size (need " UINTX_FORMAT " 64K pages) - shmctl failed with %d.",
1987                size / (64*K), errno);
1988     // I want to know if this ever happens.
1989     assert(false, "failed to set page size for shmat");
1990   }
1991 
1992   // Now attach the shared segment.
1993   // Note that I attach with SHM_RND - which means that the requested address is rounded down, if
1994   // needed, to the next lowest segment boundary. Otherwise the attach would fail if the address
1995   // were not a segment boundary.
1996   char* const addr = (char*) shmat(shmid, requested_addr, SHM_RND);
1997   const int errno_shmat = errno;
1998 
1999   // (A) Right after shmat and before handing shmat errors delete the shm segment.
2000   if (::shmctl(shmid, IPC_RMID, NULL) == -1) {
2001     trcVerbose("shmctl(%u, IPC_RMID) failed (%d)\n", shmid, errno);
2002     assert(false, "failed to remove shared memory segment!");
2003   }
2004 
2005   // Handle shmat error. If we failed to attach, just return.
2006   if (addr == (char*)-1) {
2007     trcVerbose("Failed to attach segment at " PTR_FORMAT " (%d).", p2i(requested_addr), errno_shmat);
2008     return NULL;
2009   }
2010 
2011   // Just for info: query the real page size. In case setting the page size did not
2012   // work (see above), the system may have given us something other then 4K (LDR_CNTRL).
2013   const size_t real_pagesize = os::Aix::query_pagesize(addr);
2014   if (real_pagesize != shmbuf.shm_pagesize) {
2015     trcVerbose("pagesize is, surprisingly, " SIZE_FORMAT, real_pagesize);
2016   }
2017 
2018   if (addr) {
2019     trcVerbose("shm-allocated " PTR_FORMAT " .. " PTR_FORMAT " (" UINTX_FORMAT " bytes, " UINTX_FORMAT " %s pages)",
2020       p2i(addr), p2i(addr + size - 1), size, size/real_pagesize, describe_pagesize(real_pagesize));
2021   } else {
2022     if (requested_addr != NULL) {
2023       trcVerbose("failed to shm-allocate " UINTX_FORMAT " bytes at with address " PTR_FORMAT ".", size, p2i(requested_addr));
2024     } else {
2025       trcVerbose("failed to shm-allocate " UINTX_FORMAT " bytes at any address.", size);
2026     }
2027   }
2028 
2029   // book-keeping
2030   vmembk_add(addr, size, real_pagesize, VMEM_SHMATED);
2031   assert0(is_aligned_to(addr, os::vm_page_size()));
2032 
2033   return addr;
2034 }
2035 
2036 static bool release_shmated_memory(char* addr, size_t size) {
2037 
2038   trcVerbose("release_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2039     p2i(addr), p2i(addr + size - 1));
2040 
2041   bool rc = false;
2042 
2043   // TODO: is there a way to verify shm size without doing bookkeeping?
2044   if (::shmdt(addr) != 0) {
2045     trcVerbose("error (%d).", errno);
2046   } else {
2047     trcVerbose("ok.");
2048     rc = true;
2049   }
2050   return rc;
2051 }
2052 
2053 static bool uncommit_shmated_memory(char* addr, size_t size) {
2054   trcVerbose("uncommit_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2055     p2i(addr), p2i(addr + size - 1));
2056 
2057   const bool rc = my_disclaim64(addr, size);
2058 
2059   if (!rc) {
2060     trcVerbose("my_disclaim64(" PTR_FORMAT ", " UINTX_FORMAT ") failed.\n", p2i(addr), size);
2061     return false;
2062   }
2063   return true;
2064 }
2065 
2066 ////////////////////////////////  mmap-based routines /////////////////////////////////
2067 
2068 // Reserve memory via mmap.
2069 // If <requested_addr> is given, an attempt is made to attach at the given address.
2070 // Failing that, memory is allocated at any address.
2071 // If <alignment_hint> is given and <requested_addr> is NULL, an attempt is made to
2072 // allocate at an address aligned with the given alignment. Failing that, memory
2073 // is aligned anywhere.
2074 static char* reserve_mmaped_memory(size_t bytes, char* requested_addr, size_t alignment_hint) {
2075   trcVerbose("reserve_mmaped_memory " UINTX_FORMAT " bytes, wishaddress " PTR_FORMAT ", "
2076     "alignment_hint " UINTX_FORMAT "...",
2077     bytes, p2i(requested_addr), alignment_hint);
2078 
2079   // If a wish address is given, but not aligned to 4K page boundary, mmap will fail.
2080   if (requested_addr && !is_aligned_to(requested_addr, os::vm_page_size()) != 0) {
2081     trcVerbose("Wish address " PTR_FORMAT " not aligned to page boundary.", p2i(requested_addr));
2082     return NULL;
2083   }
2084 
2085   // We must prevent anyone from attaching too close to the
2086   // BRK because that may cause malloc OOM.
2087   if (requested_addr != NULL && is_close_to_brk((address)requested_addr)) {
2088     trcVerbose("Wish address " PTR_FORMAT " is too close to the BRK segment. "
2089       "Will attach anywhere.", p2i(requested_addr));
2090     // Act like the OS refused to attach there.
2091     requested_addr = NULL;
2092   }
2093 
2094   // Specify one or the other but not both.
2095   assert0(!(requested_addr != NULL && alignment_hint > 0));
2096 
2097   // In 64K mode, we claim the global page size (os::vm_page_size())
2098   // is 64K. This is one of the few points where that illusion may
2099   // break, because mmap() will always return memory aligned to 4K. So
2100   // we must ensure we only ever return memory aligned to 64k.
2101   if (alignment_hint) {
2102     alignment_hint = lcm(alignment_hint, os::vm_page_size());
2103   } else {
2104     alignment_hint = os::vm_page_size();
2105   }
2106 
2107   // Size shall always be a multiple of os::vm_page_size (esp. in 64K mode).
2108   const size_t size = align_up(bytes, os::vm_page_size());
2109 
2110   // alignment: Allocate memory large enough to include an aligned range of the right size and
2111   // cut off the leading and trailing waste pages.
2112   assert0(alignment_hint != 0 && is_aligned_to(alignment_hint, os::vm_page_size())); // see above
2113   const size_t extra_size = size + alignment_hint;
2114 
2115   // Note: MAP_SHARED (instead of MAP_PRIVATE) needed to be able to
2116   // later use msync(MS_INVALIDATE) (see os::uncommit_memory).
2117   int flags = MAP_ANONYMOUS | MAP_SHARED;
2118 
2119   // MAP_FIXED is needed to enforce requested_addr - manpage is vague about what
2120   // it means if wishaddress is given but MAP_FIXED is not set.
2121   //
2122   // Important! Behaviour differs depending on whether SPEC1170 mode is active or not.
2123   // SPEC1170 mode active: behaviour like POSIX, MAP_FIXED will clobber existing mappings.
2124   // SPEC1170 mode not active: behaviour, unlike POSIX, is that no existing mappings will
2125   // get clobbered.
2126   if (requested_addr != NULL) {
2127     if (!os::Aix::xpg_sus_mode()) {  // not SPEC1170 Behaviour
2128       flags |= MAP_FIXED;
2129     }
2130   }
2131 
2132   char* addr = (char*)::mmap(requested_addr, extra_size,
2133       PROT_READ|PROT_WRITE|PROT_EXEC, flags, -1, 0);
2134 
2135   if (addr == MAP_FAILED) {
2136     trcVerbose("mmap(" PTR_FORMAT ", " UINTX_FORMAT ", ..) failed (%d)", p2i(requested_addr), size, errno);
2137     return NULL;
2138   }
2139 
2140   // Handle alignment.
2141   char* const addr_aligned = align_up(addr, alignment_hint);
2142   const size_t waste_pre = addr_aligned - addr;
2143   char* const addr_aligned_end = addr_aligned + size;
2144   const size_t waste_post = extra_size - waste_pre - size;
2145   if (waste_pre > 0) {
2146     ::munmap(addr, waste_pre);
2147   }
2148   if (waste_post > 0) {
2149     ::munmap(addr_aligned_end, waste_post);
2150   }
2151   addr = addr_aligned;
2152 
2153   if (addr) {
2154     trcVerbose("mmap-allocated " PTR_FORMAT " .. " PTR_FORMAT " (" UINTX_FORMAT " bytes)",
2155       p2i(addr), p2i(addr + bytes), bytes);
2156   } else {
2157     if (requested_addr != NULL) {
2158       trcVerbose("failed to mmap-allocate " UINTX_FORMAT " bytes at wish address " PTR_FORMAT ".", bytes, p2i(requested_addr));
2159     } else {
2160       trcVerbose("failed to mmap-allocate " UINTX_FORMAT " bytes at any address.", bytes);
2161     }
2162   }
2163 
2164   // bookkeeping
2165   vmembk_add(addr, size, 4*K, VMEM_MAPPED);
2166 
2167   // Test alignment, see above.
2168   assert0(is_aligned_to(addr, os::vm_page_size()));
2169 
2170   return addr;
2171 }
2172 
2173 static bool release_mmaped_memory(char* addr, size_t size) {
2174   assert0(is_aligned_to(addr, os::vm_page_size()));
2175   assert0(is_aligned_to(size, os::vm_page_size()));
2176 
2177   trcVerbose("release_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2178     p2i(addr), p2i(addr + size - 1));
2179   bool rc = false;
2180 
2181   if (::munmap(addr, size) != 0) {
2182     trcVerbose("failed (%d)\n", errno);
2183     rc = false;
2184   } else {
2185     trcVerbose("ok.");
2186     rc = true;
2187   }
2188 
2189   return rc;
2190 }
2191 
2192 static bool uncommit_mmaped_memory(char* addr, size_t size) {
2193 
2194   assert0(is_aligned_to(addr, os::vm_page_size()));
2195   assert0(is_aligned_to(size, os::vm_page_size()));
2196 
2197   trcVerbose("uncommit_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
2198     p2i(addr), p2i(addr + size - 1));
2199   bool rc = false;
2200 
2201   // Uncommit mmap memory with msync MS_INVALIDATE.
2202   if (::msync(addr, size, MS_INVALIDATE) != 0) {
2203     trcVerbose("failed (%d)\n", errno);
2204     rc = false;
2205   } else {
2206     trcVerbose("ok.");
2207     rc = true;
2208   }
2209 
2210   return rc;
2211 }
2212 
2213 int os::vm_page_size() {
2214   // Seems redundant as all get out.
2215   assert(os::Aix::page_size() != -1, "must call os::init");
2216   return os::Aix::page_size();
2217 }
2218 
2219 // Aix allocates memory by pages.
2220 int os::vm_allocation_granularity() {
2221   assert(os::Aix::page_size() != -1, "must call os::init");
2222   return os::Aix::page_size();
2223 }
2224 
2225 #ifdef PRODUCT
2226 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2227                                     int err) {
2228   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2229           ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
2230           os::errno_name(err), err);
2231 }
2232 #endif
2233 
2234 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2235                                   const char* mesg) {
2236   assert(mesg != NULL, "mesg must be specified");
2237   if (!pd_commit_memory(addr, size, exec)) {
2238     // Add extra info in product mode for vm_exit_out_of_memory():
2239     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2240     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2241   }
2242 }
2243 
2244 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2245 
2246   assert(is_aligned_to(addr, os::vm_page_size()),
2247     "addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2248     p2i(addr), os::vm_page_size());
2249   assert(is_aligned_to(size, os::vm_page_size()),
2250     "size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2251     size, os::vm_page_size());
2252 
2253   vmembk_t* const vmi = vmembk_find(addr);
2254   guarantee0(vmi);
2255   vmi->assert_is_valid_subrange(addr, size);
2256 
2257   trcVerbose("commit_memory [" PTR_FORMAT " - " PTR_FORMAT "].", p2i(addr), p2i(addr + size - 1));
2258 
2259   if (UseExplicitCommit) {
2260     // AIX commits memory on touch. So, touch all pages to be committed.
2261     for (char* p = addr; p < (addr + size); p += 4*K) {
2262       *p = '\0';
2263     }
2264   }
2265 
2266   return true;
2267 }
2268 
2269 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, bool exec) {
2270   return pd_commit_memory(addr, size, exec);
2271 }
2272 
2273 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2274                                   size_t alignment_hint, bool exec,
2275                                   const char* mesg) {
2276   // Alignment_hint is ignored on this OS.
2277   pd_commit_memory_or_exit(addr, size, exec, mesg);
2278 }
2279 
2280 bool os::pd_uncommit_memory(char* addr, size_t size) {
2281   assert(is_aligned_to(addr, os::vm_page_size()),
2282     "addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2283     p2i(addr), os::vm_page_size());
2284   assert(is_aligned_to(size, os::vm_page_size()),
2285     "size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
2286     size, os::vm_page_size());
2287 
2288   // Dynamically do different things for mmap/shmat.
2289   const vmembk_t* const vmi = vmembk_find(addr);
2290   guarantee0(vmi);
2291   vmi->assert_is_valid_subrange(addr, size);
2292 
2293   if (vmi->type == VMEM_SHMATED) {
2294     return uncommit_shmated_memory(addr, size);
2295   } else {
2296     return uncommit_mmaped_memory(addr, size);
2297   }
2298 }
2299 
2300 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2301   // Do not call this; no need to commit stack pages on AIX.
2302   ShouldNotReachHere();
2303   return true;
2304 }
2305 
2306 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2307   // Do not call this; no need to commit stack pages on AIX.
2308   ShouldNotReachHere();
2309   return true;
2310 }
2311 
2312 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2313 }
2314 
2315 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2316 }
2317 
2318 void os::numa_make_global(char *addr, size_t bytes) {
2319 }
2320 
2321 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2322 }
2323 
2324 bool os::numa_topology_changed() {
2325   return false;
2326 }
2327 
2328 size_t os::numa_get_groups_num() {
2329   return 1;
2330 }
2331 
2332 int os::numa_get_group_id() {
2333   return 0;
2334 }
2335 
2336 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2337   if (size > 0) {
2338     ids[0] = 0;
2339     return 1;
2340   }
2341   return 0;
2342 }
2343 
2344 int os::numa_get_group_id_for_address(const void* address) {
2345   return 0;
2346 }
2347 
2348 bool os::get_page_info(char *start, page_info* info) {
2349   return false;
2350 }
2351 
2352 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2353   return end;
2354 }
2355 
2356 // Reserves and attaches a shared memory segment.
2357 // Will assert if a wish address is given and could not be obtained.
2358 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, size_t alignment_hint) {
2359 
2360   // All other Unices do a mmap(MAP_FIXED) if the addr is given,
2361   // thereby clobbering old mappings at that place. That is probably
2362   // not intended, never used and almost certainly an error were it
2363   // ever be used this way (to try attaching at a specified address
2364   // without clobbering old mappings an alternate API exists,
2365   // os::attempt_reserve_memory_at()).
2366   // Instead of mimicking the dangerous coding of the other platforms, here I
2367   // just ignore the request address (release) or assert(debug).
2368   assert0(requested_addr == NULL);
2369 
2370   // Always round to os::vm_page_size(), which may be larger than 4K.
2371   bytes = align_up(bytes, os::vm_page_size());
2372   const size_t alignment_hint0 =
2373     alignment_hint ? align_up(alignment_hint, os::vm_page_size()) : 0;
2374 
2375   // In 4K mode always use mmap.
2376   // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2377   if (os::vm_page_size() == 4*K) {
2378     return reserve_mmaped_memory(bytes, requested_addr, alignment_hint);
2379   } else {
2380     if (bytes >= Use64KPagesThreshold) {
2381       return reserve_shmated_memory(bytes, requested_addr, alignment_hint);
2382     } else {
2383       return reserve_mmaped_memory(bytes, requested_addr, alignment_hint);
2384     }
2385   }
2386 }
2387 
2388 bool os::pd_release_memory(char* addr, size_t size) {
2389 
2390   // Dynamically do different things for mmap/shmat.
2391   vmembk_t* const vmi = vmembk_find(addr);
2392   guarantee0(vmi);
2393 
2394   // Always round to os::vm_page_size(), which may be larger than 4K.
2395   size = align_up(size, os::vm_page_size());
2396   addr = align_up(addr, os::vm_page_size());
2397 
2398   bool rc = false;
2399   bool remove_bookkeeping = false;
2400   if (vmi->type == VMEM_SHMATED) {
2401     // For shmatted memory, we do:
2402     // - If user wants to release the whole range, release the memory (shmdt).
2403     // - If user only wants to release a partial range, uncommit (disclaim) that
2404     //   range. That way, at least, we do not use memory anymore (bust still page
2405     //   table space).
2406     vmi->assert_is_valid_subrange(addr, size);
2407     if (addr == vmi->addr && size == vmi->size) {
2408       rc = release_shmated_memory(addr, size);
2409       remove_bookkeeping = true;
2410     } else {
2411       rc = uncommit_shmated_memory(addr, size);
2412     }
2413   } else {
2414     // User may unmap partial regions but region has to be fully contained.
2415 #ifdef ASSERT
2416     vmi->assert_is_valid_subrange(addr, size);
2417 #endif
2418     rc = release_mmaped_memory(addr, size);
2419     remove_bookkeeping = true;
2420   }
2421 
2422   // update bookkeeping
2423   if (rc && remove_bookkeeping) {
2424     vmembk_remove(vmi);
2425   }
2426 
2427   return rc;
2428 }
2429 
2430 static bool checked_mprotect(char* addr, size_t size, int prot) {
2431 
2432   // Little problem here: if SPEC1170 behaviour is off, mprotect() on AIX will
2433   // not tell me if protection failed when trying to protect an un-protectable range.
2434   //
2435   // This means if the memory was allocated using shmget/shmat, protection wont work
2436   // but mprotect will still return 0:
2437   //
2438   // See http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.basetechref/doc/basetrf1/mprotect.htm
2439 
2440   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
2441   bool rc = ::mprotect(addr, size, prot) == 0 ? true : false;
2442 
2443   if (!rc) {
2444     const char* const s_errno = os::errno_name(errno);
2445     warning("mprotect(" PTR_FORMAT "-" PTR_FORMAT ", 0x%X) failed (%s).", addr, addr + size, prot, s_errno);
2446     return false;
2447   }
2448 
2449   // mprotect success check
2450   //
2451   // Mprotect said it changed the protection but can I believe it?
2452   //
2453   // To be sure I need to check the protection afterwards. Try to
2454   // read from protected memory and check whether that causes a segfault.
2455   //
2456   if (!os::Aix::xpg_sus_mode()) {
2457 
2458     if (CanUseSafeFetch32()) {
2459 
2460       const bool read_protected =
2461         (SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
2462          SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
2463 
2464       if (prot & PROT_READ) {
2465         rc = !read_protected;
2466       } else {
2467         rc = read_protected;
2468       }
2469 
2470       if (!rc) {
2471         if (os::Aix::on_pase()) {
2472           // There is an issue on older PASE systems where mprotect() will return success but the
2473           // memory will not be protected.
2474           // This has nothing to do with the problem of using mproect() on SPEC1170 incompatible
2475           // machines; we only see it rarely, when using mprotect() to protect the guard page of
2476           // a stack. It is an OS error.
2477           //
2478           // A valid strategy is just to try again. This usually works. :-/
2479 
2480           ::usleep(1000);
2481           Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
2482           if (::mprotect(addr, size, prot) == 0) {
2483             const bool read_protected_2 =
2484               (SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
2485               SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
2486             rc = true;
2487           }
2488         }
2489       }
2490     }
2491   }
2492 
2493   assert(rc == true, "mprotect failed.");
2494 
2495   return rc;
2496 }
2497 
2498 // Set protections specified
2499 bool os::protect_memory(char* addr, size_t size, ProtType prot, bool is_committed) {
2500   unsigned int p = 0;
2501   switch (prot) {
2502   case MEM_PROT_NONE: p = PROT_NONE; break;
2503   case MEM_PROT_READ: p = PROT_READ; break;
2504   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2505   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2506   default:
2507     ShouldNotReachHere();
2508   }
2509   // is_committed is unused.
2510   return checked_mprotect(addr, size, p);
2511 }
2512 
2513 bool os::guard_memory(char* addr, size_t size) {
2514   return checked_mprotect(addr, size, PROT_NONE);
2515 }
2516 
2517 bool os::unguard_memory(char* addr, size_t size) {
2518   return checked_mprotect(addr, size, PROT_READ|PROT_WRITE|PROT_EXEC);
2519 }
2520 
2521 // Large page support
2522 
2523 static size_t _large_page_size = 0;
2524 
2525 // Enable large page support if OS allows that.
2526 void os::large_page_init() {
2527   return; // Nothing to do. See query_multipage_support and friends.
2528 }
2529 
2530 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2531   // reserve_memory_special() is used to allocate large paged memory. On AIX, we implement
2532   // 64k paged memory reservation using the normal memory allocation paths (os::reserve_memory()),
2533   // so this is not needed.
2534   assert(false, "should not be called on AIX");
2535   return NULL;
2536 }
2537 
2538 bool os::release_memory_special(char* base, size_t bytes) {
2539   // Detaching the SHM segment will also delete it, see reserve_memory_special().
2540   Unimplemented();
2541   return false;
2542 }
2543 
2544 size_t os::large_page_size() {
2545   return _large_page_size;
2546 }
2547 
2548 bool os::can_commit_large_page_memory() {
2549   // Does not matter, we do not support huge pages.
2550   return false;
2551 }
2552 
2553 bool os::can_execute_large_page_memory() {
2554   // Does not matter, we do not support huge pages.
2555   return false;
2556 }
2557 
2558 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2559   assert(file_desc >= 0, "file_desc is not valid");
2560   char* result = NULL;
2561 
2562   // Always round to os::vm_page_size(), which may be larger than 4K.
2563   bytes = align_up(bytes, os::vm_page_size());
2564   result = reserve_mmaped_memory(bytes, requested_addr, 0);
2565 
2566   if (result != NULL) {
2567     if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2568       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2569     }
2570   }
2571   return result;
2572 }
2573 
2574 // Reserve memory at an arbitrary address, only if that area is
2575 // available (and not reserved for something else).
2576 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2577   char* addr = NULL;
2578 
2579   // Always round to os::vm_page_size(), which may be larger than 4K.
2580   bytes = align_up(bytes, os::vm_page_size());
2581 
2582   // In 4K mode always use mmap.
2583   // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2584   if (os::vm_page_size() == 4*K) {
2585     return reserve_mmaped_memory(bytes, requested_addr, 0);
2586   } else {
2587     if (bytes >= Use64KPagesThreshold) {
2588       return reserve_shmated_memory(bytes, requested_addr, 0);
2589     } else {
2590       return reserve_mmaped_memory(bytes, requested_addr, 0);
2591     }
2592   }
2593 
2594   return addr;
2595 }
2596 
2597 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2598 void os::infinite_sleep() {
2599   while (true) {    // sleep forever ...
2600     ::sleep(100);   // ... 100 seconds at a time
2601   }
2602 }
2603 
2604 // Used to convert frequent JVM_Yield() to nops
2605 bool os::dont_yield() {
2606   return DontYieldALot;
2607 }
2608 
2609 void os::naked_yield() {
2610   sched_yield();
2611 }
2612 
2613 ////////////////////////////////////////////////////////////////////////////////
2614 // thread priority support
2615 
2616 // From AIX manpage to pthread_setschedparam
2617 // (see: http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?
2618 //    topic=/com.ibm.aix.basetechref/doc/basetrf1/pthread_setschedparam.htm):
2619 //
2620 // "If schedpolicy is SCHED_OTHER, then sched_priority must be in the
2621 // range from 40 to 80, where 40 is the least favored priority and 80
2622 // is the most favored."
2623 //
2624 // (Actually, I doubt this even has an impact on AIX, as we do kernel
2625 // scheduling there; however, this still leaves iSeries.)
2626 //
2627 // We use the same values for AIX and PASE.
2628 int os::java_to_os_priority[CriticalPriority + 1] = {
2629   54,             // 0 Entry should never be used
2630 
2631   55,             // 1 MinPriority
2632   55,             // 2
2633   56,             // 3
2634 
2635   56,             // 4
2636   57,             // 5 NormPriority
2637   57,             // 6
2638 
2639   58,             // 7
2640   58,             // 8
2641   59,             // 9 NearMaxPriority
2642 
2643   60,             // 10 MaxPriority
2644 
2645   60              // 11 CriticalPriority
2646 };
2647 
2648 static int prio_init() {
2649   if (ThreadPriorityPolicy == 1) {
2650     if (geteuid() != 0) {
2651       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2652         warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
2653                 "e.g., being the root user. If the necessary permission is not " \
2654                 "possessed, changes to priority will be silently ignored.");
2655       }
2656     }
2657   }
2658   if (UseCriticalJavaThreadPriority) {
2659     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2660   }
2661   return 0;
2662 }
2663 
2664 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2665   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2666   pthread_t thr = thread->osthread()->pthread_id();
2667   int policy = SCHED_OTHER;
2668   struct sched_param param;
2669   param.sched_priority = newpri;
2670   int ret = pthread_setschedparam(thr, policy, &param);
2671 
2672   if (ret != 0) {
2673     trcVerbose("Could not change priority for thread %d to %d (error %d, %s)",
2674         (int)thr, newpri, ret, os::errno_name(ret));
2675   }
2676   return (ret == 0) ? OS_OK : OS_ERR;
2677 }
2678 
2679 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2680   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2681     *priority_ptr = java_to_os_priority[NormPriority];
2682     return OS_OK;
2683   }
2684   pthread_t thr = thread->osthread()->pthread_id();
2685   int policy = SCHED_OTHER;
2686   struct sched_param param;
2687   int ret = pthread_getschedparam(thr, &policy, &param);
2688   *priority_ptr = param.sched_priority;
2689 
2690   return (ret == 0) ? OS_OK : OS_ERR;
2691 }
2692 
2693 ////////////////////////////////////////////////////////////////////////////////
2694 // suspend/resume support
2695 
2696 //  The low-level signal-based suspend/resume support is a remnant from the
2697 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2698 //  within hotspot. Currently used by JFR's OSThreadSampler
2699 //
2700 //  The remaining code is greatly simplified from the more general suspension
2701 //  code that used to be used.
2702 //
2703 //  The protocol is quite simple:
2704 //  - suspend:
2705 //      - sends a signal to the target thread
2706 //      - polls the suspend state of the osthread using a yield loop
2707 //      - target thread signal handler (SR_handler) sets suspend state
2708 //        and blocks in sigsuspend until continued
2709 //  - resume:
2710 //      - sets target osthread state to continue
2711 //      - sends signal to end the sigsuspend loop in the SR_handler
2712 //
2713 //  Note that the SR_lock plays no role in this suspend/resume protocol,
2714 //  but is checked for NULL in SR_handler as a thread termination indicator.
2715 //  The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
2716 //
2717 //  Note that resume_clear_context() and suspend_save_context() are needed
2718 //  by SR_handler(), so that fetch_frame_from_ucontext() works,
2719 //  which in part is used by:
2720 //    - Forte Analyzer: AsyncGetCallTrace()
2721 //    - StackBanging: get_frame_at_stack_banging_point()
2722 
2723 static void resume_clear_context(OSThread *osthread) {
2724   osthread->set_ucontext(NULL);
2725   osthread->set_siginfo(NULL);
2726 }
2727 
2728 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2729   osthread->set_ucontext(context);
2730   osthread->set_siginfo(siginfo);
2731 }
2732 
2733 //
2734 // Handler function invoked when a thread's execution is suspended or
2735 // resumed. We have to be careful that only async-safe functions are
2736 // called here (Note: most pthread functions are not async safe and
2737 // should be avoided.)
2738 //
2739 // Note: sigwait() is a more natural fit than sigsuspend() from an
2740 // interface point of view, but sigwait() prevents the signal hander
2741 // from being run. libpthread would get very confused by not having
2742 // its signal handlers run and prevents sigwait()'s use with the
2743 // mutex granting granting signal.
2744 //
2745 // Currently only ever called on the VMThread and JavaThreads (PC sampling).
2746 //
2747 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2748   // Save and restore errno to avoid confusing native code with EINTR
2749   // after sigsuspend.
2750   int old_errno = errno;
2751 
2752   Thread* thread = Thread::current_or_null_safe();
2753   assert(thread != NULL, "Missing current thread in SR_handler");
2754 
2755   // On some systems we have seen signal delivery get "stuck" until the signal
2756   // mask is changed as part of thread termination. Check that the current thread
2757   // has not already terminated (via SR_lock()) - else the following assertion
2758   // will fail because the thread is no longer a JavaThread as the ~JavaThread
2759   // destructor has completed.
2760 
2761   if (thread->SR_lock() == NULL) {
2762     return;
2763   }
2764 
2765   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2766 
2767   OSThread* osthread = thread->osthread();
2768 
2769   os::SuspendResume::State current = osthread->sr.state();
2770   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2771     suspend_save_context(osthread, siginfo, context);
2772 
2773     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2774     os::SuspendResume::State state = osthread->sr.suspended();
2775     if (state == os::SuspendResume::SR_SUSPENDED) {
2776       sigset_t suspend_set;  // signals for sigsuspend()
2777       sigemptyset(&suspend_set);
2778       // get current set of blocked signals and unblock resume signal
2779       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2780       sigdelset(&suspend_set, SR_signum);
2781 
2782       // wait here until we are resumed
2783       while (1) {
2784         sigsuspend(&suspend_set);
2785 
2786         os::SuspendResume::State result = osthread->sr.running();
2787         if (result == os::SuspendResume::SR_RUNNING) {
2788           break;
2789         }
2790       }
2791 
2792     } else if (state == os::SuspendResume::SR_RUNNING) {
2793       // request was cancelled, continue
2794     } else {
2795       ShouldNotReachHere();
2796     }
2797 
2798     resume_clear_context(osthread);
2799   } else if (current == os::SuspendResume::SR_RUNNING) {
2800     // request was cancelled, continue
2801   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2802     // ignore
2803   } else {
2804     ShouldNotReachHere();
2805   }
2806 
2807   errno = old_errno;
2808 }
2809 
2810 static int SR_initialize() {
2811   struct sigaction act;
2812   char *s;
2813   // Get signal number to use for suspend/resume
2814   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2815     int sig = ::strtol(s, 0, 10);
2816     if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
2817         sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
2818       SR_signum = sig;
2819     } else {
2820       warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2821               sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2822     }
2823   }
2824 
2825   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2826         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2827 
2828   sigemptyset(&SR_sigset);
2829   sigaddset(&SR_sigset, SR_signum);
2830 
2831   // Set up signal handler for suspend/resume.
2832   act.sa_flags = SA_RESTART|SA_SIGINFO;
2833   act.sa_handler = (void (*)(int)) SR_handler;
2834 
2835   // SR_signum is blocked by default.
2836   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2837 
2838   if (sigaction(SR_signum, &act, 0) == -1) {
2839     return -1;
2840   }
2841 
2842   // Save signal flag
2843   os::Aix::set_our_sigflags(SR_signum, act.sa_flags);
2844   return 0;
2845 }
2846 
2847 static int SR_finalize() {
2848   return 0;
2849 }
2850 
2851 static int sr_notify(OSThread* osthread) {
2852   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2853   assert_status(status == 0, status, "pthread_kill");
2854   return status;
2855 }
2856 
2857 // "Randomly" selected value for how long we want to spin
2858 // before bailing out on suspending a thread, also how often
2859 // we send a signal to a thread we want to resume
2860 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2861 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2862 
2863 // returns true on success and false on error - really an error is fatal
2864 // but this seems the normal response to library errors
2865 static bool do_suspend(OSThread* osthread) {
2866   assert(osthread->sr.is_running(), "thread should be running");
2867   // mark as suspended and send signal
2868 
2869   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2870     // failed to switch, state wasn't running?
2871     ShouldNotReachHere();
2872     return false;
2873   }
2874 
2875   if (sr_notify(osthread) != 0) {
2876     // try to cancel, switch to running
2877 
2878     os::SuspendResume::State result = osthread->sr.cancel_suspend();
2879     if (result == os::SuspendResume::SR_RUNNING) {
2880       // cancelled
2881       return false;
2882     } else if (result == os::SuspendResume::SR_SUSPENDED) {
2883       // somehow managed to suspend
2884       return true;
2885     } else {
2886       ShouldNotReachHere();
2887       return false;
2888     }
2889   }
2890 
2891   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2892 
2893   for (int n = 0; !osthread->sr.is_suspended(); n++) {
2894     for (int i = 0; i < RANDOMLY_LARGE_INTEGER2 && !osthread->sr.is_suspended(); i++) {
2895       os::naked_yield();
2896     }
2897 
2898     // timeout, try to cancel the request
2899     if (n >= RANDOMLY_LARGE_INTEGER) {
2900       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2901       if (cancelled == os::SuspendResume::SR_RUNNING) {
2902         return false;
2903       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2904         return true;
2905       } else {
2906         ShouldNotReachHere();
2907         return false;
2908       }
2909     }
2910   }
2911 
2912   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2913   return true;
2914 }
2915 
2916 static void do_resume(OSThread* osthread) {
2917   //assert(osthread->sr.is_suspended(), "thread should be suspended");
2918 
2919   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2920     // failed to switch to WAKEUP_REQUEST
2921     ShouldNotReachHere();
2922     return;
2923   }
2924 
2925   while (!osthread->sr.is_running()) {
2926     if (sr_notify(osthread) == 0) {
2927       for (int n = 0; n < RANDOMLY_LARGE_INTEGER && !osthread->sr.is_running(); n++) {
2928         for (int i = 0; i < 100 && !osthread->sr.is_running(); i++) {
2929           os::naked_yield();
2930         }
2931       }
2932     } else {
2933       ShouldNotReachHere();
2934     }
2935   }
2936 
2937   guarantee(osthread->sr.is_running(), "Must be running!");
2938 }
2939 
2940 ///////////////////////////////////////////////////////////////////////////////////
2941 // signal handling (except suspend/resume)
2942 
2943 // This routine may be used by user applications as a "hook" to catch signals.
2944 // The user-defined signal handler must pass unrecognized signals to this
2945 // routine, and if it returns true (non-zero), then the signal handler must
2946 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2947 // routine will never retun false (zero), but instead will execute a VM panic
2948 // routine kill the process.
2949 //
2950 // If this routine returns false, it is OK to call it again. This allows
2951 // the user-defined signal handler to perform checks either before or after
2952 // the VM performs its own checks. Naturally, the user code would be making
2953 // a serious error if it tried to handle an exception (such as a null check
2954 // or breakpoint) that the VM was generating for its own correct operation.
2955 //
2956 // This routine may recognize any of the following kinds of signals:
2957 //   SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2958 // It should be consulted by handlers for any of those signals.
2959 //
2960 // The caller of this routine must pass in the three arguments supplied
2961 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2962 // field of the structure passed to sigaction(). This routine assumes that
2963 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2964 //
2965 // Note that the VM will print warnings if it detects conflicting signal
2966 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2967 //
2968 extern "C" JNIEXPORT int
2969 JVM_handle_aix_signal(int signo, siginfo_t* siginfo, void* ucontext, int abort_if_unrecognized);
2970 
2971 // Set thread signal mask (for some reason on AIX sigthreadmask() seems
2972 // to be the thing to call; documentation is not terribly clear about whether
2973 // pthread_sigmask also works, and if it does, whether it does the same.
2974 bool set_thread_signal_mask(int how, const sigset_t* set, sigset_t* oset) {
2975   const int rc = ::pthread_sigmask(how, set, oset);
2976   // return value semantics differ slightly for error case:
2977   // pthread_sigmask returns error number, sigthreadmask -1 and sets global errno
2978   // (so, pthread_sigmask is more theadsafe for error handling)
2979   // But success is always 0.
2980   return rc == 0 ? true : false;
2981 }
2982 
2983 // Function to unblock all signals which are, according
2984 // to POSIX, typical program error signals. If they happen while being blocked,
2985 // they typically will bring down the process immediately.
2986 bool unblock_program_error_signals() {
2987   sigset_t set;
2988   ::sigemptyset(&set);
2989   ::sigaddset(&set, SIGILL);
2990   ::sigaddset(&set, SIGBUS);
2991   ::sigaddset(&set, SIGFPE);
2992   ::sigaddset(&set, SIGSEGV);
2993   return set_thread_signal_mask(SIG_UNBLOCK, &set, NULL);
2994 }
2995 
2996 // Renamed from 'signalHandler' to avoid collision with other shared libs.
2997 static void javaSignalHandler(int sig, siginfo_t* info, void* uc) {
2998   assert(info != NULL && uc != NULL, "it must be old kernel");
2999 
3000   // Never leave program error signals blocked;
3001   // on all our platforms they would bring down the process immediately when
3002   // getting raised while being blocked.
3003   unblock_program_error_signals();
3004 
3005   int orig_errno = errno;  // Preserve errno value over signal handler.
3006   JVM_handle_aix_signal(sig, info, uc, true);
3007   errno = orig_errno;
3008 }
3009 
3010 // This boolean allows users to forward their own non-matching signals
3011 // to JVM_handle_aix_signal, harmlessly.
3012 bool os::Aix::signal_handlers_are_installed = false;
3013 
3014 // For signal-chaining
3015 bool os::Aix::libjsig_is_loaded = false;
3016 typedef struct sigaction *(*get_signal_t)(int);
3017 get_signal_t os::Aix::get_signal_action = NULL;
3018 
3019 struct sigaction* os::Aix::get_chained_signal_action(int sig) {
3020   struct sigaction *actp = NULL;
3021 
3022   if (libjsig_is_loaded) {
3023     // Retrieve the old signal handler from libjsig
3024     actp = (*get_signal_action)(sig);
3025   }
3026   if (actp == NULL) {
3027     // Retrieve the preinstalled signal handler from jvm
3028     actp = os::Posix::get_preinstalled_handler(sig);
3029   }
3030 
3031   return actp;
3032 }
3033 
3034 static bool call_chained_handler(struct sigaction *actp, int sig,
3035                                  siginfo_t *siginfo, void *context) {
3036   // Call the old signal handler
3037   if (actp->sa_handler == SIG_DFL) {
3038     // It's more reasonable to let jvm treat it as an unexpected exception
3039     // instead of taking the default action.
3040     return false;
3041   } else if (actp->sa_handler != SIG_IGN) {
3042     if ((actp->sa_flags & SA_NODEFER) == 0) {
3043       // automaticlly block the signal
3044       sigaddset(&(actp->sa_mask), sig);
3045     }
3046 
3047     sa_handler_t hand = NULL;
3048     sa_sigaction_t sa = NULL;
3049     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3050     // retrieve the chained handler
3051     if (siginfo_flag_set) {
3052       sa = actp->sa_sigaction;
3053     } else {
3054       hand = actp->sa_handler;
3055     }
3056 
3057     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3058       actp->sa_handler = SIG_DFL;
3059     }
3060 
3061     // try to honor the signal mask
3062     sigset_t oset;
3063     sigemptyset(&oset);
3064     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3065 
3066     // call into the chained handler
3067     if (siginfo_flag_set) {
3068       (*sa)(sig, siginfo, context);
3069     } else {
3070       (*hand)(sig);
3071     }
3072 
3073     // restore the signal mask
3074     pthread_sigmask(SIG_SETMASK, &oset, NULL);
3075   }
3076   // Tell jvm's signal handler the signal is taken care of.
3077   return true;
3078 }
3079 
3080 bool os::Aix::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3081   bool chained = false;
3082   // signal-chaining
3083   if (UseSignalChaining) {
3084     struct sigaction *actp = get_chained_signal_action(sig);
3085     if (actp != NULL) {
3086       chained = call_chained_handler(actp, sig, siginfo, context);
3087     }
3088   }
3089   return chained;
3090 }
3091 
3092 // for diagnostic
3093 int sigflags[NSIG];
3094 
3095 int os::Aix::get_our_sigflags(int sig) {
3096   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3097   return sigflags[sig];
3098 }
3099 
3100 void os::Aix::set_our_sigflags(int sig, int flags) {
3101   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3102   if (sig > 0 && sig < NSIG) {
3103     sigflags[sig] = flags;
3104   }
3105 }
3106 
3107 void os::Aix::set_signal_handler(int sig, bool set_installed) {
3108   // Check for overwrite.
3109   struct sigaction oldAct;
3110   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3111 
3112   void* oldhand = oldAct.sa_sigaction
3113     ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3114     : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3115   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3116       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3117       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)javaSignalHandler)) {
3118     if (AllowUserSignalHandlers || !set_installed) {
3119       // Do not overwrite; user takes responsibility to forward to us.
3120       return;
3121     } else if (UseSignalChaining) {
3122       // save the old handler in jvm
3123       os::Posix::save_preinstalled_handler(sig, oldAct);
3124       // libjsig also interposes the sigaction() call below and saves the
3125       // old sigaction on it own.
3126     } else {
3127       fatal("Encountered unexpected pre-existing sigaction handler "
3128             "%#lx for signal %d.", (long)oldhand, sig);
3129     }
3130   }
3131 
3132   struct sigaction sigAct;
3133   sigfillset(&(sigAct.sa_mask));
3134   if (!set_installed) {
3135     sigAct.sa_handler = SIG_DFL;
3136     sigAct.sa_flags = SA_RESTART;
3137   } else {
3138     sigAct.sa_sigaction = javaSignalHandler;
3139     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3140   }
3141   // Save flags, which are set by ours
3142   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3143   sigflags[sig] = sigAct.sa_flags;
3144 
3145   int ret = sigaction(sig, &sigAct, &oldAct);
3146   assert(ret == 0, "check");
3147 
3148   void* oldhand2 = oldAct.sa_sigaction
3149                  ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3150                  : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3151   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3152 }
3153 
3154 // install signal handlers for signals that HotSpot needs to
3155 // handle in order to support Java-level exception handling.
3156 void os::Aix::install_signal_handlers() {
3157   if (!signal_handlers_are_installed) {
3158     signal_handlers_are_installed = true;
3159 
3160     // signal-chaining
3161     typedef void (*signal_setting_t)();
3162     signal_setting_t begin_signal_setting = NULL;
3163     signal_setting_t end_signal_setting = NULL;
3164     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3165                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3166     if (begin_signal_setting != NULL) {
3167       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3168                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3169       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3170                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3171       libjsig_is_loaded = true;
3172       assert(UseSignalChaining, "should enable signal-chaining");
3173     }
3174     if (libjsig_is_loaded) {
3175       // Tell libjsig jvm is setting signal handlers.
3176       (*begin_signal_setting)();
3177     }
3178 
3179     set_signal_handler(SIGSEGV, true);
3180     set_signal_handler(SIGPIPE, true);
3181     set_signal_handler(SIGBUS, true);
3182     set_signal_handler(SIGILL, true);
3183     set_signal_handler(SIGFPE, true);
3184     set_signal_handler(SIGTRAP, true);
3185     set_signal_handler(SIGXFSZ, true);
3186 
3187     if (libjsig_is_loaded) {
3188       // Tell libjsig jvm finishes setting signal handlers.
3189       (*end_signal_setting)();
3190     }
3191 
3192     // We don't activate signal checker if libjsig is in place, we trust ourselves
3193     // and if UserSignalHandler is installed all bets are off.
3194     // Log that signal checking is off only if -verbose:jni is specified.
3195     if (CheckJNICalls) {
3196       if (libjsig_is_loaded) {
3197         tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3198         check_signals = false;
3199       }
3200       if (AllowUserSignalHandlers) {
3201         tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3202         check_signals = false;
3203       }
3204       // Need to initialize check_signal_done.
3205       ::sigemptyset(&check_signal_done);
3206     }
3207   }
3208 }
3209 
3210 static const char* get_signal_handler_name(address handler,
3211                                            char* buf, int buflen) {
3212   int offset;
3213   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3214   if (found) {
3215     // skip directory names
3216     const char *p1, *p2;
3217     p1 = buf;
3218     size_t len = strlen(os::file_separator());
3219     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3220     // The way os::dll_address_to_library_name is implemented on Aix
3221     // right now, it always returns -1 for the offset which is not
3222     // terribly informative.
3223     // Will fix that. For now, omit the offset.
3224     jio_snprintf(buf, buflen, "%s", p1);
3225   } else {
3226     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3227   }
3228   return buf;
3229 }
3230 
3231 static void print_signal_handler(outputStream* st, int sig,
3232                                  char* buf, size_t buflen) {
3233   struct sigaction sa;
3234   sigaction(sig, NULL, &sa);
3235 
3236   st->print("%s: ", os::exception_name(sig, buf, buflen));
3237 
3238   address handler = (sa.sa_flags & SA_SIGINFO)
3239     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3240     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3241 
3242   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3243     st->print("SIG_DFL");
3244   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3245     st->print("SIG_IGN");
3246   } else {
3247     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3248   }
3249 
3250   // Print readable mask.
3251   st->print(", sa_mask[0]=");
3252   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3253 
3254   address rh = VMError::get_resetted_sighandler(sig);
3255   // May be, handler was resetted by VMError?
3256   if (rh != NULL) {
3257     handler = rh;
3258     sa.sa_flags = VMError::get_resetted_sigflags(sig);
3259   }
3260 
3261   // Print textual representation of sa_flags.
3262   st->print(", sa_flags=");
3263   os::Posix::print_sa_flags(st, sa.sa_flags);
3264 
3265   // Check: is it our handler?
3266   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)javaSignalHandler) ||
3267       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3268     // It is our signal handler.
3269     // Check for flags, reset system-used one!
3270     if ((int)sa.sa_flags != os::Aix::get_our_sigflags(sig)) {
3271       st->print(", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3272                 os::Aix::get_our_sigflags(sig));
3273     }
3274   }
3275   st->cr();
3276 }
3277 
3278 #define DO_SIGNAL_CHECK(sig) \
3279   if (!sigismember(&check_signal_done, sig)) \
3280     os::Aix::check_signal_handler(sig)
3281 
3282 // This method is a periodic task to check for misbehaving JNI applications
3283 // under CheckJNI, we can add any periodic checks here
3284 
3285 void os::run_periodic_checks() {
3286 
3287   if (check_signals == false) return;
3288 
3289   // SEGV and BUS if overridden could potentially prevent
3290   // generation of hs*.log in the event of a crash, debugging
3291   // such a case can be very challenging, so we absolutely
3292   // check the following for a good measure:
3293   DO_SIGNAL_CHECK(SIGSEGV);
3294   DO_SIGNAL_CHECK(SIGILL);
3295   DO_SIGNAL_CHECK(SIGFPE);
3296   DO_SIGNAL_CHECK(SIGBUS);
3297   DO_SIGNAL_CHECK(SIGPIPE);
3298   DO_SIGNAL_CHECK(SIGXFSZ);
3299   if (UseSIGTRAP) {
3300     DO_SIGNAL_CHECK(SIGTRAP);
3301   }
3302 
3303   // ReduceSignalUsage allows the user to override these handlers
3304   // see comments at the very top and jvm_md.h
3305   if (!ReduceSignalUsage) {
3306     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3307     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3308     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3309     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3310   }
3311 
3312   DO_SIGNAL_CHECK(SR_signum);
3313 }
3314 
3315 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3316 
3317 static os_sigaction_t os_sigaction = NULL;
3318 
3319 void os::Aix::check_signal_handler(int sig) {
3320   char buf[O_BUFLEN];
3321   address jvmHandler = NULL;
3322 
3323   struct sigaction act;
3324   if (os_sigaction == NULL) {
3325     // only trust the default sigaction, in case it has been interposed
3326     os_sigaction = CAST_TO_FN_PTR(os_sigaction_t, dlsym(RTLD_DEFAULT, "sigaction"));
3327     if (os_sigaction == NULL) return;
3328   }
3329 
3330   os_sigaction(sig, (struct sigaction*)NULL, &act);
3331 
3332   address thisHandler = (act.sa_flags & SA_SIGINFO)
3333     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3334     : CAST_FROM_FN_PTR(address, act.sa_handler);
3335 
3336   switch(sig) {
3337   case SIGSEGV:
3338   case SIGBUS:
3339   case SIGFPE:
3340   case SIGPIPE:
3341   case SIGILL:
3342   case SIGXFSZ:
3343     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)javaSignalHandler);
3344     break;
3345 
3346   case SHUTDOWN1_SIGNAL:
3347   case SHUTDOWN2_SIGNAL:
3348   case SHUTDOWN3_SIGNAL:
3349   case BREAK_SIGNAL:
3350     jvmHandler = (address)user_handler();
3351     break;
3352 
3353   default:
3354     if (sig == SR_signum) {
3355       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3356     } else {
3357       return;
3358     }
3359     break;
3360   }
3361 
3362   if (thisHandler != jvmHandler) {
3363     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3364     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3365     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3366     // No need to check this sig any longer
3367     sigaddset(&check_signal_done, sig);
3368     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3369     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3370       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3371                     exception_name(sig, buf, O_BUFLEN));
3372     }
3373   } else if (os::Aix::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Aix::get_our_sigflags(sig)) {
3374     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3375     tty->print("expected:");
3376     os::Posix::print_sa_flags(tty, os::Aix::get_our_sigflags(sig));
3377     tty->cr();
3378     tty->print("  found:");
3379     os::Posix::print_sa_flags(tty, act.sa_flags);
3380     tty->cr();
3381     // No need to check this sig any longer
3382     sigaddset(&check_signal_done, sig);
3383   }
3384 
3385   // Dump all the signal
3386   if (sigismember(&check_signal_done, sig)) {
3387     print_signal_handlers(tty, buf, O_BUFLEN);
3388   }
3389 }
3390 
3391 // To install functions for atexit system call
3392 extern "C" {
3393   static void perfMemory_exit_helper() {
3394     perfMemory_exit();
3395   }
3396 }
3397 
3398 // This is called _before_ the most of global arguments have been parsed.
3399 void os::init(void) {
3400   // This is basic, we want to know if that ever changes.
3401   // (Shared memory boundary is supposed to be a 256M aligned.)
3402   assert(SHMLBA == ((uint64_t)0x10000000ULL)/*256M*/, "unexpected");
3403 
3404   // Record process break at startup.
3405   g_brk_at_startup = (address) ::sbrk(0);
3406   assert(g_brk_at_startup != (address) -1, "sbrk failed");
3407 
3408   // First off, we need to know whether we run on AIX or PASE, and
3409   // the OS level we run on.
3410   os::Aix::initialize_os_info();
3411 
3412   // Scan environment (SPEC1170 behaviour, etc).
3413   os::Aix::scan_environment();
3414 
3415   // Probe multipage support.
3416   query_multipage_support();
3417 
3418   // Act like we only have one page size by eliminating corner cases which
3419   // we did not support very well anyway.
3420   // We have two input conditions:
3421   // 1) Data segment page size. This is controlled by linker setting (datapsize) on the
3422   //    launcher, and/or by LDR_CNTRL environment variable. The latter overrules the linker
3423   //    setting.
3424   //    Data segment page size is important for us because it defines the thread stack page
3425   //    size, which is needed for guard page handling, stack banging etc.
3426   // 2) The ability to allocate 64k pages dynamically. If this is a given, java heap can
3427   //    and should be allocated with 64k pages.
3428   //
3429   // So, we do the following:
3430   // LDR_CNTRL    can_use_64K_pages_dynamically       what we do                      remarks
3431   // 4K           no                                  4K                              old systems (aix 5.2, as/400 v5r4) or new systems with AME activated
3432   // 4k           yes                                 64k (treat 4k stacks as 64k)    different loader than java and standard settings
3433   // 64k          no              --- AIX 5.2 ? ---
3434   // 64k          yes                                 64k                             new systems and standard java loader (we set datapsize=64k when linking)
3435 
3436   // We explicitly leave no option to change page size, because only upgrading would work,
3437   // not downgrading (if stack page size is 64k you cannot pretend its 4k).
3438 
3439   if (g_multipage_support.datapsize == 4*K) {
3440     // datapsize = 4K. Data segment, thread stacks are 4K paged.
3441     if (g_multipage_support.can_use_64K_pages) {
3442       // .. but we are able to use 64K pages dynamically.
3443       // This would be typical for java launchers which are not linked
3444       // with datapsize=64K (like, any other launcher but our own).
3445       //
3446       // In this case it would be smart to allocate the java heap with 64K
3447       // to get the performance benefit, and to fake 64k pages for the
3448       // data segment (when dealing with thread stacks).
3449       //
3450       // However, leave a possibility to downgrade to 4K, using
3451       // -XX:-Use64KPages.
3452       if (Use64KPages) {
3453         trcVerbose("64K page mode (faked for data segment)");
3454         Aix::_page_size = 64*K;
3455       } else {
3456         trcVerbose("4K page mode (Use64KPages=off)");
3457         Aix::_page_size = 4*K;
3458       }
3459     } else {
3460       // .. and not able to allocate 64k pages dynamically. Here, just
3461       // fall back to 4K paged mode and use mmap for everything.
3462       trcVerbose("4K page mode");
3463       Aix::_page_size = 4*K;
3464       FLAG_SET_ERGO(Use64KPages, false);
3465     }
3466   } else {
3467     // datapsize = 64k. Data segment, thread stacks are 64k paged.
3468     // This normally means that we can allocate 64k pages dynamically.
3469     // (There is one special case where this may be false: EXTSHM=on.
3470     // but we decided to not support that mode).
3471     assert0(g_multipage_support.can_use_64K_pages);
3472     Aix::_page_size = 64*K;
3473     trcVerbose("64K page mode");
3474     FLAG_SET_ERGO(Use64KPages, true);
3475   }
3476 
3477   // For now UseLargePages is just ignored.
3478   FLAG_SET_ERGO(UseLargePages, false);
3479   _page_sizes[0] = 0;
3480 
3481   // debug trace
3482   trcVerbose("os::vm_page_size %s", describe_pagesize(os::vm_page_size()));
3483 
3484   // Next, we need to initialize libo4 and libperfstat libraries.
3485   if (os::Aix::on_pase()) {
3486     os::Aix::initialize_libo4();
3487   } else {
3488     os::Aix::initialize_libperfstat();
3489   }
3490 
3491   // Reset the perfstat information provided by ODM.
3492   if (os::Aix::on_aix()) {
3493     libperfstat::perfstat_reset();
3494   }
3495 
3496   // Now initialze basic system properties. Note that for some of the values we
3497   // need libperfstat etc.
3498   os::Aix::initialize_system_info();
3499 
3500   clock_tics_per_sec = sysconf(_SC_CLK_TCK);
3501 
3502   init_random(1234567);
3503 
3504   // _main_thread points to the thread that created/loaded the JVM.
3505   Aix::_main_thread = pthread_self();
3506 
3507   initial_time_count = javaTimeNanos();
3508 
3509   os::Posix::init();
3510 }
3511 
3512 // This is called _after_ the global arguments have been parsed.
3513 jint os::init_2(void) {
3514 
3515   // This could be set after os::Posix::init() but all platforms
3516   // have to set it the same so we have to mirror Solaris.
3517   DEBUG_ONLY(os::set_mutex_init_done();)
3518 
3519   os::Posix::init_2();
3520 
3521   if (os::Aix::on_pase()) {
3522     trcVerbose("Running on PASE.");
3523   } else {
3524     trcVerbose("Running on AIX (not PASE).");
3525   }
3526 
3527   trcVerbose("processor count: %d", os::_processor_count);
3528   trcVerbose("physical memory: %lu", Aix::_physical_memory);
3529 
3530   // Initially build up the loaded dll map.
3531   LoadedLibraries::reload();
3532   if (Verbose) {
3533     trcVerbose("Loaded Libraries: ");
3534     LoadedLibraries::print(tty);
3535   }
3536 
3537   // initialize suspend/resume support - must do this before signal_sets_init()
3538   if (SR_initialize() != 0) {
3539     perror("SR_initialize failed");
3540     return JNI_ERR;
3541   }
3542 
3543   Aix::signal_sets_init();
3544   Aix::install_signal_handlers();
3545   // Initialize data for jdk.internal.misc.Signal
3546   if (!ReduceSignalUsage) {
3547     jdk_misc_signal_init();
3548   }
3549 
3550   // Check and sets minimum stack sizes against command line options
3551   if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
3552     return JNI_ERR;
3553   }
3554 
3555   if (UseNUMA) {
3556     UseNUMA = false;
3557     warning("NUMA optimizations are not available on this OS.");
3558   }
3559 
3560   if (MaxFDLimit) {
3561     // Set the number of file descriptors to max. print out error
3562     // if getrlimit/setrlimit fails but continue regardless.
3563     struct rlimit nbr_files;
3564     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3565     if (status != 0) {
3566       log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3567     } else {
3568       nbr_files.rlim_cur = nbr_files.rlim_max;
3569       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3570       if (status != 0) {
3571         log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3572       }
3573     }
3574   }
3575 
3576   if (PerfAllowAtExitRegistration) {
3577     // Only register atexit functions if PerfAllowAtExitRegistration is set.
3578     // At exit functions can be delayed until process exit time, which
3579     // can be problematic for embedded VM situations. Embedded VMs should
3580     // call DestroyJavaVM() to assure that VM resources are released.
3581 
3582     // Note: perfMemory_exit_helper atexit function may be removed in
3583     // the future if the appropriate cleanup code can be added to the
3584     // VM_Exit VMOperation's doit method.
3585     if (atexit(perfMemory_exit_helper) != 0) {
3586       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
3587     }
3588   }
3589 
3590   // initialize thread priority policy
3591   prio_init();
3592 
3593   return JNI_OK;
3594 }
3595 
3596 // Mark the polling page as unreadable
3597 void os::make_polling_page_unreadable(void) {
3598   if (!guard_memory((char*)_polling_page, Aix::page_size())) {
3599     fatal("Could not disable polling page");
3600   }
3601 };
3602 
3603 // Mark the polling page as readable
3604 void os::make_polling_page_readable(void) {
3605   // Changed according to os_linux.cpp.
3606   if (!checked_mprotect((char *)_polling_page, Aix::page_size(), PROT_READ)) {
3607     fatal("Could not enable polling page at " PTR_FORMAT, _polling_page);
3608   }
3609 };
3610 
3611 int os::active_processor_count() {
3612   // User has overridden the number of active processors
3613   if (ActiveProcessorCount > 0) {
3614     log_trace(os)("active_processor_count: "
3615                   "active processor count set by user : %d",
3616                   ActiveProcessorCount);
3617     return ActiveProcessorCount;
3618   }
3619 
3620   int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
3621   assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check");
3622   return online_cpus;
3623 }
3624 
3625 void os::set_native_thread_name(const char *name) {
3626   // Not yet implemented.
3627   return;
3628 }
3629 
3630 bool os::bind_to_processor(uint processor_id) {
3631   // Not yet implemented.
3632   return false;
3633 }
3634 
3635 void os::SuspendedThreadTask::internal_do_task() {
3636   if (do_suspend(_thread->osthread())) {
3637     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3638     do_task(context);
3639     do_resume(_thread->osthread());
3640   }
3641 }
3642 
3643 ////////////////////////////////////////////////////////////////////////////////
3644 // debug support
3645 
3646 bool os::find(address addr, outputStream* st) {
3647 
3648   st->print(PTR_FORMAT ": ", addr);
3649 
3650   loaded_module_t lm;
3651   if (LoadedLibraries::find_for_text_address(addr, &lm) != NULL ||
3652       LoadedLibraries::find_for_data_address(addr, &lm) != NULL) {
3653     st->print_cr("%s", lm.path);
3654     return true;
3655   }
3656 
3657   return false;
3658 }
3659 
3660 ////////////////////////////////////////////////////////////////////////////////
3661 // misc
3662 
3663 // This does not do anything on Aix. This is basically a hook for being
3664 // able to use structured exception handling (thread-local exception filters)
3665 // on, e.g., Win32.
3666 void
3667 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
3668                          JavaCallArguments* args, Thread* thread) {
3669   f(value, method, args, thread);
3670 }
3671 
3672 void os::print_statistics() {
3673 }
3674 
3675 bool os::message_box(const char* title, const char* message) {
3676   int i;
3677   fdStream err(defaultStream::error_fd());
3678   for (i = 0; i < 78; i++) err.print_raw("=");
3679   err.cr();
3680   err.print_raw_cr(title);
3681   for (i = 0; i < 78; i++) err.print_raw("-");
3682   err.cr();
3683   err.print_raw_cr(message);
3684   for (i = 0; i < 78; i++) err.print_raw("=");
3685   err.cr();
3686 
3687   char buf[16];
3688   // Prevent process from exiting upon "read error" without consuming all CPU
3689   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3690 
3691   return buf[0] == 'y' || buf[0] == 'Y';
3692 }
3693 
3694 // Is a (classpath) directory empty?
3695 bool os::dir_is_empty(const char* path) {
3696   DIR *dir = NULL;
3697   struct dirent *ptr;
3698 
3699   dir = opendir(path);
3700   if (dir == NULL) return true;
3701 
3702   /* Scan the directory */
3703   bool result = true;
3704   while (result && (ptr = readdir(dir)) != NULL) {
3705     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3706       result = false;
3707     }
3708   }
3709   closedir(dir);
3710   return result;
3711 }
3712 
3713 // This code originates from JDK's sysOpen and open64_w
3714 // from src/solaris/hpi/src/system_md.c
3715 
3716 int os::open(const char *path, int oflag, int mode) {
3717 
3718   if (strlen(path) > MAX_PATH - 1) {
3719     errno = ENAMETOOLONG;
3720     return -1;
3721   }
3722   int fd;
3723 
3724   fd = ::open64(path, oflag, mode);
3725   if (fd == -1) return -1;
3726 
3727   // If the open succeeded, the file might still be a directory.
3728   {
3729     struct stat64 buf64;
3730     int ret = ::fstat64(fd, &buf64);
3731     int st_mode = buf64.st_mode;
3732 
3733     if (ret != -1) {
3734       if ((st_mode & S_IFMT) == S_IFDIR) {
3735         errno = EISDIR;
3736         ::close(fd);
3737         return -1;
3738       }
3739     } else {
3740       ::close(fd);
3741       return -1;
3742     }
3743   }
3744 
3745   // All file descriptors that are opened in the JVM and not
3746   // specifically destined for a subprocess should have the
3747   // close-on-exec flag set. If we don't set it, then careless 3rd
3748   // party native code might fork and exec without closing all
3749   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3750   // UNIXProcess.c), and this in turn might:
3751   //
3752   // - cause end-of-file to fail to be detected on some file
3753   //   descriptors, resulting in mysterious hangs, or
3754   //
3755   // - might cause an fopen in the subprocess to fail on a system
3756   //   suffering from bug 1085341.
3757   //
3758   // (Yes, the default setting of the close-on-exec flag is a Unix
3759   // design flaw.)
3760   //
3761   // See:
3762   // 1085341: 32-bit stdio routines should support file descriptors >255
3763   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3764   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3765 #ifdef FD_CLOEXEC
3766   {
3767     int flags = ::fcntl(fd, F_GETFD);
3768     if (flags != -1)
3769       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3770   }
3771 #endif
3772 
3773   return fd;
3774 }
3775 
3776 // create binary file, rewriting existing file if required
3777 int os::create_binary_file(const char* path, bool rewrite_existing) {
3778   int oflags = O_WRONLY | O_CREAT;
3779   if (!rewrite_existing) {
3780     oflags |= O_EXCL;
3781   }
3782   return ::open64(path, oflags, S_IREAD | S_IWRITE);
3783 }
3784 
3785 // return current position of file pointer
3786 jlong os::current_file_offset(int fd) {
3787   return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
3788 }
3789 
3790 // move file pointer to the specified offset
3791 jlong os::seek_to_file_offset(int fd, jlong offset) {
3792   return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
3793 }
3794 
3795 // This code originates from JDK's sysAvailable
3796 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3797 
3798 int os::available(int fd, jlong *bytes) {
3799   jlong cur, end;
3800   int mode;
3801   struct stat64 buf64;
3802 
3803   if (::fstat64(fd, &buf64) >= 0) {
3804     mode = buf64.st_mode;
3805     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3806       int n;
3807       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3808         *bytes = n;
3809         return 1;
3810       }
3811     }
3812   }
3813   if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
3814     return 0;
3815   } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
3816     return 0;
3817   } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
3818     return 0;
3819   }
3820   *bytes = end - cur;
3821   return 1;
3822 }
3823 
3824 // Map a block of memory.
3825 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3826                         char *addr, size_t bytes, bool read_only,
3827                         bool allow_exec) {
3828   int prot;
3829   int flags = MAP_PRIVATE;
3830 
3831   if (read_only) {
3832     prot = PROT_READ;
3833     flags = MAP_SHARED;
3834   } else {
3835     prot = PROT_READ | PROT_WRITE;
3836     flags = MAP_PRIVATE;
3837   }
3838 
3839   if (allow_exec) {
3840     prot |= PROT_EXEC;
3841   }
3842 
3843   if (addr != NULL) {
3844     flags |= MAP_FIXED;
3845   }
3846 
3847   // Allow anonymous mappings if 'fd' is -1.
3848   if (fd == -1) {
3849     flags |= MAP_ANONYMOUS;
3850   }
3851 
3852   char* mapped_address = (char*)::mmap(addr, (size_t)bytes, prot, flags,
3853                                      fd, file_offset);
3854   if (mapped_address == MAP_FAILED) {
3855     return NULL;
3856   }
3857   return mapped_address;
3858 }
3859 
3860 // Remap a block of memory.
3861 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3862                           char *addr, size_t bytes, bool read_only,
3863                           bool allow_exec) {
3864   // same as map_memory() on this OS
3865   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3866                         allow_exec);
3867 }
3868 
3869 // Unmap a block of memory.
3870 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3871   return munmap(addr, bytes) == 0;
3872 }
3873 
3874 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3875 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3876 // of a thread.
3877 //
3878 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3879 // the fast estimate available on the platform.
3880 
3881 jlong os::current_thread_cpu_time() {
3882   // return user + sys since the cost is the same
3883   const jlong n = os::thread_cpu_time(Thread::current(), true /* user + sys */);
3884   assert(n >= 0, "negative CPU time");
3885   return n;
3886 }
3887 
3888 jlong os::thread_cpu_time(Thread* thread) {
3889   // consistent with what current_thread_cpu_time() returns
3890   const jlong n = os::thread_cpu_time(thread, true /* user + sys */);
3891   assert(n >= 0, "negative CPU time");
3892   return n;
3893 }
3894 
3895 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3896   const jlong n = os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3897   assert(n >= 0, "negative CPU time");
3898   return n;
3899 }
3900 
3901 static bool thread_cpu_time_unchecked(Thread* thread, jlong* p_sys_time, jlong* p_user_time) {
3902   bool error = false;
3903 
3904   jlong sys_time = 0;
3905   jlong user_time = 0;
3906 
3907   // Reimplemented using getthrds64().
3908   //
3909   // Works like this:
3910   // For the thread in question, get the kernel thread id. Then get the
3911   // kernel thread statistics using that id.
3912   //
3913   // This only works of course when no pthread scheduling is used,
3914   // i.e. there is a 1:1 relationship to kernel threads.
3915   // On AIX, see AIXTHREAD_SCOPE variable.
3916 
3917   pthread_t pthtid = thread->osthread()->pthread_id();
3918 
3919   // retrieve kernel thread id for the pthread:
3920   tid64_t tid = 0;
3921   struct __pthrdsinfo pinfo;
3922   // I just love those otherworldly IBM APIs which force me to hand down
3923   // dummy buffers for stuff I dont care for...
3924   char dummy[1];
3925   int dummy_size = sizeof(dummy);
3926   if (pthread_getthrds_np(&pthtid, PTHRDSINFO_QUERY_TID, &pinfo, sizeof(pinfo),
3927                           dummy, &dummy_size) == 0) {
3928     tid = pinfo.__pi_tid;
3929   } else {
3930     tty->print_cr("pthread_getthrds_np failed.");
3931     error = true;
3932   }
3933 
3934   // retrieve kernel timing info for that kernel thread
3935   if (!error) {
3936     struct thrdentry64 thrdentry;
3937     if (getthrds64(getpid(), &thrdentry, sizeof(thrdentry), &tid, 1) == 1) {
3938       sys_time = thrdentry.ti_ru.ru_stime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_stime.tv_usec * 1000LL;
3939       user_time = thrdentry.ti_ru.ru_utime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_utime.tv_usec * 1000LL;
3940     } else {
3941       tty->print_cr("pthread_getthrds_np failed.");
3942       error = true;
3943     }
3944   }
3945 
3946   if (p_sys_time) {
3947     *p_sys_time = sys_time;
3948   }
3949 
3950   if (p_user_time) {
3951     *p_user_time = user_time;
3952   }
3953 
3954   if (error) {
3955     return false;
3956   }
3957 
3958   return true;
3959 }
3960 
3961 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3962   jlong sys_time;
3963   jlong user_time;
3964 
3965   if (!thread_cpu_time_unchecked(thread, &sys_time, &user_time)) {
3966     return -1;
3967   }
3968 
3969   return user_sys_cpu_time ? sys_time + user_time : user_time;
3970 }
3971 
3972 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3973   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3974   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3975   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3976   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3977 }
3978 
3979 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3980   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3981   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3982   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3983   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3984 }
3985 
3986 bool os::is_thread_cpu_time_supported() {
3987   return true;
3988 }
3989 
3990 // System loadavg support. Returns -1 if load average cannot be obtained.
3991 // For now just return the system wide load average (no processor sets).
3992 int os::loadavg(double values[], int nelem) {
3993 
3994   guarantee(nelem >= 0 && nelem <= 3, "argument error");
3995   guarantee(values, "argument error");
3996 
3997   if (os::Aix::on_pase()) {
3998 
3999     // AS/400 PASE: use libo4 porting library
4000     double v[3] = { 0.0, 0.0, 0.0 };
4001 
4002     if (libo4::get_load_avg(v, v + 1, v + 2)) {
4003       for (int i = 0; i < nelem; i ++) {
4004         values[i] = v[i];
4005       }
4006       return nelem;
4007     } else {
4008       return -1;
4009     }
4010 
4011   } else {
4012 
4013     // AIX: use libperfstat
4014     libperfstat::cpuinfo_t ci;
4015     if (libperfstat::get_cpuinfo(&ci)) {
4016       for (int i = 0; i < nelem; i++) {
4017         values[i] = ci.loadavg[i];
4018       }
4019     } else {
4020       return -1;
4021     }
4022     return nelem;
4023   }
4024 }
4025 
4026 void os::pause() {
4027   char filename[MAX_PATH];
4028   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4029     jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
4030   } else {
4031     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4032   }
4033 
4034   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4035   if (fd != -1) {
4036     struct stat buf;
4037     ::close(fd);
4038     while (::stat(filename, &buf) == 0) {
4039       (void)::poll(NULL, 0, 100);
4040     }
4041   } else {
4042     trcVerbose("Could not open pause file '%s', continuing immediately.", filename);
4043   }
4044 }
4045 
4046 bool os::is_primordial_thread(void) {
4047   if (pthread_self() == (pthread_t)1) {
4048     return true;
4049   } else {
4050     return false;
4051   }
4052 }
4053 
4054 // OS recognitions (PASE/AIX, OS level) call this before calling any
4055 // one of Aix::on_pase(), Aix::os_version() static
4056 void os::Aix::initialize_os_info() {
4057 
4058   assert(_on_pase == -1 && _os_version == 0, "already called.");
4059 
4060   struct utsname uts;
4061   memset(&uts, 0, sizeof(uts));
4062   strcpy(uts.sysname, "?");
4063   if (::uname(&uts) == -1) {
4064     trcVerbose("uname failed (%d)", errno);
4065     guarantee(0, "Could not determine whether we run on AIX or PASE");
4066   } else {
4067     trcVerbose("uname says: sysname \"%s\" version \"%s\" release \"%s\" "
4068                "node \"%s\" machine \"%s\"\n",
4069                uts.sysname, uts.version, uts.release, uts.nodename, uts.machine);
4070     const int major = atoi(uts.version);
4071     assert(major > 0, "invalid OS version");
4072     const int minor = atoi(uts.release);
4073     assert(minor > 0, "invalid OS release");
4074     _os_version = (major << 24) | (minor << 16);
4075     char ver_str[20] = {0};
4076     const char* name_str = "unknown OS";
4077     if (strcmp(uts.sysname, "OS400") == 0) {
4078       // We run on AS/400 PASE. We do not support versions older than V5R4M0.
4079       _on_pase = 1;
4080       if (os_version_short() < 0x0504) {
4081         trcVerbose("OS/400 releases older than V5R4M0 not supported.");
4082         assert(false, "OS/400 release too old.");
4083       }
4084       name_str = "OS/400 (pase)";
4085       jio_snprintf(ver_str, sizeof(ver_str), "%u.%u", major, minor);
4086     } else if (strcmp(uts.sysname, "AIX") == 0) {
4087       // We run on AIX. We do not support versions older than AIX 7.1.
4088       _on_pase = 0;
4089       // Determine detailed AIX version: Version, Release, Modification, Fix Level.
4090       odmWrapper::determine_os_kernel_version(&_os_version);
4091       if (os_version_short() < 0x0701) {
4092         trcVerbose("AIX releases older than AIX 7.1 are not supported.");
4093         assert(false, "AIX release too old.");
4094       }
4095       name_str = "AIX";
4096       jio_snprintf(ver_str, sizeof(ver_str), "%u.%u.%u.%u",
4097                    major, minor, (_os_version >> 8) & 0xFF, _os_version & 0xFF);
4098     } else {
4099       assert(false, "%s", name_str);
4100     }
4101     trcVerbose("We run on %s %s", name_str, ver_str);
4102   }
4103 
4104   guarantee(_on_pase != -1 && _os_version, "Could not determine AIX/OS400 release");
4105 } // end: os::Aix::initialize_os_info()
4106 
4107 // Scan environment for important settings which might effect the VM.
4108 // Trace out settings. Warn about invalid settings and/or correct them.
4109 //
4110 // Must run after os::Aix::initialue_os_info().
4111 void os::Aix::scan_environment() {
4112 
4113   char* p;
4114   int rc;
4115 
4116   // Warn explicity if EXTSHM=ON is used. That switch changes how
4117   // System V shared memory behaves. One effect is that page size of
4118   // shared memory cannot be change dynamically, effectivly preventing
4119   // large pages from working.
4120   // This switch was needed on AIX 32bit, but on AIX 64bit the general
4121   // recommendation is (in OSS notes) to switch it off.
4122   p = ::getenv("EXTSHM");
4123   trcVerbose("EXTSHM=%s.", p ? p : "<unset>");
4124   if (p && strcasecmp(p, "ON") == 0) {
4125     _extshm = 1;
4126     trcVerbose("*** Unsupported mode! Please remove EXTSHM from your environment! ***");
4127     if (!AllowExtshm) {
4128       // We allow under certain conditions the user to continue. However, we want this
4129       // to be a fatal error by default. On certain AIX systems, leaving EXTSHM=ON means
4130       // that the VM is not able to allocate 64k pages for the heap.
4131       // We do not want to run with reduced performance.
4132       vm_exit_during_initialization("EXTSHM is ON. Please remove EXTSHM from your environment.");
4133     }
4134   } else {
4135     _extshm = 0;
4136   }
4137 
4138   // SPEC1170 behaviour: will change the behaviour of a number of POSIX APIs.
4139   // Not tested, not supported.
4140   //
4141   // Note that it might be worth the trouble to test and to require it, if only to
4142   // get useful return codes for mprotect.
4143   //
4144   // Note: Setting XPG_SUS_ENV in the process is too late. Must be set earlier (before
4145   // exec() ? before loading the libjvm ? ....)
4146   p = ::getenv("XPG_SUS_ENV");
4147   trcVerbose("XPG_SUS_ENV=%s.", p ? p : "<unset>");
4148   if (p && strcmp(p, "ON") == 0) {
4149     _xpg_sus_mode = 1;
4150     trcVerbose("Unsupported setting: XPG_SUS_ENV=ON");
4151     // This is not supported. Worst of all, it changes behaviour of mmap MAP_FIXED to
4152     // clobber address ranges. If we ever want to support that, we have to do some
4153     // testing first.
4154     guarantee(false, "XPG_SUS_ENV=ON not supported");
4155   } else {
4156     _xpg_sus_mode = 0;
4157   }
4158 
4159   if (os::Aix::on_pase()) {
4160     p = ::getenv("QIBM_MULTI_THREADED");
4161     trcVerbose("QIBM_MULTI_THREADED=%s.", p ? p : "<unset>");
4162   }
4163 
4164   p = ::getenv("LDR_CNTRL");
4165   trcVerbose("LDR_CNTRL=%s.", p ? p : "<unset>");
4166   if (os::Aix::on_pase() && os::Aix::os_version_short() == 0x0701) {
4167     if (p && ::strstr(p, "TEXTPSIZE")) {
4168       trcVerbose("*** WARNING - LDR_CNTRL contains TEXTPSIZE. "
4169         "you may experience hangs or crashes on OS/400 V7R1.");
4170     }
4171   }
4172 
4173   p = ::getenv("AIXTHREAD_GUARDPAGES");
4174   trcVerbose("AIXTHREAD_GUARDPAGES=%s.", p ? p : "<unset>");
4175 
4176 } // end: os::Aix::scan_environment()
4177 
4178 // PASE: initialize the libo4 library (PASE porting library).
4179 void os::Aix::initialize_libo4() {
4180   guarantee(os::Aix::on_pase(), "OS/400 only.");
4181   if (!libo4::init()) {
4182     trcVerbose("libo4 initialization failed.");
4183     assert(false, "libo4 initialization failed");
4184   } else {
4185     trcVerbose("libo4 initialized.");
4186   }
4187 }
4188 
4189 // AIX: initialize the libperfstat library.
4190 void os::Aix::initialize_libperfstat() {
4191   assert(os::Aix::on_aix(), "AIX only");
4192   if (!libperfstat::init()) {
4193     trcVerbose("libperfstat initialization failed.");
4194     assert(false, "libperfstat initialization failed");
4195   } else {
4196     trcVerbose("libperfstat initialized.");
4197   }
4198 }
4199 
4200 /////////////////////////////////////////////////////////////////////////////
4201 // thread stack
4202 
4203 // Get the current stack base from the OS (actually, the pthread library).
4204 // Note: usually not page aligned.
4205 address os::current_stack_base() {
4206   AixMisc::stackbounds_t bounds;
4207   bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
4208   guarantee(rc, "Unable to retrieve stack bounds.");
4209   return bounds.base;
4210 }
4211 
4212 // Get the current stack size from the OS (actually, the pthread library).
4213 // Returned size is such that (base - size) is always aligned to page size.
4214 size_t os::current_stack_size() {
4215   AixMisc::stackbounds_t bounds;
4216   bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
4217   guarantee(rc, "Unable to retrieve stack bounds.");
4218   // Align the returned stack size such that the stack low address
4219   // is aligned to page size (Note: base is usually not and we do not care).
4220   // We need to do this because caller code will assume stack low address is
4221   // page aligned and will place guard pages without checking.
4222   address low = bounds.base - bounds.size;
4223   address low_aligned = (address)align_up(low, os::vm_page_size());
4224   size_t s = bounds.base - low_aligned;
4225   return s;
4226 }
4227 
4228 extern char** environ;
4229 
4230 // Run the specified command in a separate process. Return its exit value,
4231 // or -1 on failure (e.g. can't fork a new process).
4232 // Unlike system(), this function can be called from signal handler. It
4233 // doesn't block SIGINT et al.
4234 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
4235   char* argv[4] = { (char*)"sh", (char*)"-c", cmd, NULL};
4236 
4237   pid_t pid = fork();
4238 
4239   if (pid < 0) {
4240     // fork failed
4241     return -1;
4242 
4243   } else if (pid == 0) {
4244     // child process
4245 
4246     // Try to be consistent with system(), which uses "/usr/bin/sh" on AIX.
4247     execve("/usr/bin/sh", argv, environ);
4248 
4249     // execve failed
4250     _exit(-1);
4251 
4252   } else {
4253     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4254     // care about the actual exit code, for now.
4255 
4256     int status;
4257 
4258     // Wait for the child process to exit. This returns immediately if
4259     // the child has already exited. */
4260     while (waitpid(pid, &status, 0) < 0) {
4261       switch (errno) {
4262         case ECHILD: return 0;
4263         case EINTR: break;
4264         default: return -1;
4265       }
4266     }
4267 
4268     if (WIFEXITED(status)) {
4269       // The child exited normally; get its exit code.
4270       return WEXITSTATUS(status);
4271     } else if (WIFSIGNALED(status)) {
4272       // The child exited because of a signal.
4273       // The best value to return is 0x80 + signal number,
4274       // because that is what all Unix shells do, and because
4275       // it allows callers to distinguish between process exit and
4276       // process death by signal.
4277       return 0x80 + WTERMSIG(status);
4278     } else {
4279       // Unknown exit code; pass it through.
4280       return status;
4281     }
4282   }
4283   return -1;
4284 }
4285 
4286 // Get the default path to the core file
4287 // Returns the length of the string
4288 int os::get_core_path(char* buffer, size_t bufferSize) {
4289   const char* p = get_current_directory(buffer, bufferSize);
4290 
4291   if (p == NULL) {
4292     assert(p != NULL, "failed to get current directory");
4293     return 0;
4294   }
4295 
4296   jio_snprintf(buffer, bufferSize, "%s/core or core.%d",
4297                                                p, current_process_id());
4298 
4299   return strlen(buffer);
4300 }
4301 
4302 #ifndef PRODUCT
4303 void TestReserveMemorySpecial_test() {
4304   // No tests available for this platform
4305 }
4306 #endif
4307 
4308 bool os::start_debugging(char *buf, int buflen) {
4309   int len = (int)strlen(buf);
4310   char *p = &buf[len];
4311 
4312   jio_snprintf(p, buflen -len,
4313                  "\n\n"
4314                  "Do you want to debug the problem?\n\n"
4315                  "To debug, run 'dbx -a %d'; then switch to thread tid " INTX_FORMAT ", k-tid " INTX_FORMAT "\n"
4316                  "Enter 'yes' to launch dbx automatically (PATH must include dbx)\n"
4317                  "Otherwise, press RETURN to abort...",
4318                  os::current_process_id(),
4319                  os::current_thread_id(), thread_self());
4320 
4321   bool yes = os::message_box("Unexpected Error", buf);
4322 
4323   if (yes) {
4324     // yes, user asked VM to launch debugger
4325     jio_snprintf(buf, buflen, "dbx -a %d", os::current_process_id());
4326 
4327     os::fork_and_exec(buf);
4328     yes = false;
4329   }
4330   return yes;
4331 }
4332 
4333 static inline time_t get_mtime(const char* filename) {
4334   struct stat st;
4335   int ret = os::stat(filename, &st);
4336   assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
4337   return st.st_mtime;
4338 }
4339 
4340 int os::compare_file_modified_times(const char* file1, const char* file2) {
4341   time_t t1 = get_mtime(file1);
4342   time_t t2 = get_mtime(file2);
4343   return t1 - t2;
4344 }
4345 
4346 bool os::supports_map_sync() {
4347   return false;
4348 }
--- EOF ---