rev 7555 : imported patch 8067469-g1-ignores-alwayspretouch
rev 7556 : [mq]: david-erik-review

   1 /*
   2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_OS_HPP
  26 #define SHARE_VM_RUNTIME_OS_HPP
  27 
  28 #include "jvmtifiles/jvmti.h"
  29 #include "runtime/extendedPC.hpp"
  30 #include "runtime/handles.hpp"
  31 #include "utilities/top.hpp"
  32 #ifdef TARGET_OS_FAMILY_linux
  33 # include "jvm_linux.h"
  34 # include <setjmp.h>
  35 #endif
  36 #ifdef TARGET_OS_FAMILY_solaris
  37 # include "jvm_solaris.h"
  38 # include <setjmp.h>
  39 #endif
  40 #ifdef TARGET_OS_FAMILY_windows
  41 # include "jvm_windows.h"
  42 #endif
  43 #ifdef TARGET_OS_FAMILY_aix
  44 # include "jvm_aix.h"
  45 # include <setjmp.h>
  46 #endif
  47 #ifdef TARGET_OS_FAMILY_bsd
  48 # include "jvm_bsd.h"
  49 # include <setjmp.h>
  50 # ifdef __APPLE__
  51 #  include <mach/mach_time.h>
  52 # endif
  53 #endif
  54 
  55 class AgentLibrary;
  56 
  57 // os defines the interface to operating system; this includes traditional
  58 // OS services (time, I/O) as well as other functionality with system-
  59 // dependent code.
  60 
  61 typedef void (*dll_func)(...);
  62 
  63 class Thread;
  64 class JavaThread;
  65 class Event;
  66 class DLL;
  67 class FileHandle;
  68 class NativeCallStack;
  69 
  70 template<class E> class GrowableArray;
  71 
  72 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
  73 
  74 // Platform-independent error return values from OS functions
  75 enum OSReturn {
  76   OS_OK         =  0,        // Operation was successful
  77   OS_ERR        = -1,        // Operation failed
  78   OS_INTRPT     = -2,        // Operation was interrupted
  79   OS_TIMEOUT    = -3,        // Operation timed out
  80   OS_NOMEM      = -5,        // Operation failed for lack of memory
  81   OS_NORESOURCE = -6         // Operation failed for lack of nonmemory resource
  82 };
  83 
  84 enum ThreadPriority {        // JLS 20.20.1-3
  85   NoPriority       = -1,     // Initial non-priority value
  86   MinPriority      =  1,     // Minimum priority
  87   NormPriority     =  5,     // Normal (non-daemon) priority
  88   NearMaxPriority  =  9,     // High priority, used for VMThread
  89   MaxPriority      = 10,     // Highest priority, used for WatcherThread
  90                              // ensures that VMThread doesn't starve profiler
  91   CriticalPriority = 11      // Critical thread priority
  92 };
  93 
  94 // Executable parameter flag for os::commit_memory() and
  95 // os::commit_memory_or_exit().
  96 const bool ExecMem = true;
  97 
  98 // Typedef for structured exception handling support
  99 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
 100 
 101 class MallocTracker;
 102 
 103 class os: AllStatic {
 104   friend class VMStructs;
 105   friend class MallocTracker;
 106  public:
 107   enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
 108 
 109  private:
 110   static OSThread*          _starting_thread;
 111   static address            _polling_page;
 112   static volatile int32_t * _mem_serialize_page;
 113   static uintptr_t          _serialize_page_mask;
 114  public:
 115   static size_t             _page_sizes[page_sizes_max];
 116 
 117  private:
 118   static void init_page_sizes(size_t default_page_size) {
 119     _page_sizes[0] = default_page_size;
 120     _page_sizes[1] = 0; // sentinel
 121   }
 122 
 123   static char*  pd_reserve_memory(size_t bytes, char* addr = 0,
 124                                size_t alignment_hint = 0);
 125   static char*  pd_attempt_reserve_memory_at(size_t bytes, char* addr);
 126   static void   pd_split_reserved_memory(char *base, size_t size,
 127                                       size_t split, bool realloc);
 128   static bool   pd_commit_memory(char* addr, size_t bytes, bool executable);
 129   static bool   pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
 130                                  bool executable);
 131   // Same as pd_commit_memory() that either succeeds or calls
 132   // vm_exit_out_of_memory() with the specified mesg.
 133   static void   pd_commit_memory_or_exit(char* addr, size_t bytes,
 134                                          bool executable, const char* mesg);
 135   static void   pd_commit_memory_or_exit(char* addr, size_t size,
 136                                          size_t alignment_hint,
 137                                          bool executable, const char* mesg);
 138   static bool   pd_uncommit_memory(char* addr, size_t bytes);
 139   static bool   pd_release_memory(char* addr, size_t bytes);
 140 
 141   static char*  pd_map_memory(int fd, const char* file_name, size_t file_offset,
 142                            char *addr, size_t bytes, bool read_only = false,
 143                            bool allow_exec = false);
 144   static char*  pd_remap_memory(int fd, const char* file_name, size_t file_offset,
 145                              char *addr, size_t bytes, bool read_only,
 146                              bool allow_exec);
 147   static bool   pd_unmap_memory(char *addr, size_t bytes);
 148   static void   pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
 149   static void   pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
 150 
 151 
 152  public:
 153   static void init(void);                      // Called before command line parsing
 154   static void init_before_ergo(void);          // Called after command line parsing
 155                                                // before VM ergonomics processing.
 156   static jint init_2(void);                    // Called after command line parsing
 157                                                // and VM ergonomics processing
 158   static void init_globals(void) {             // Called from init_globals() in init.cpp
 159     init_globals_ext();
 160   }
 161 
 162   // File names are case-insensitive on windows only
 163   // Override me as needed
 164   static int    file_name_strcmp(const char* s1, const char* s2);
 165 
 166   // get/unset environment variable
 167   static bool getenv(const char* name, char* buffer, int len);
 168   static bool unsetenv(const char* name);
 169 
 170   static bool have_special_privileges();
 171 
 172   static jlong  javaTimeMillis();
 173   static jlong  javaTimeNanos();
 174   static void   javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
 175   static void   run_periodic_checks();
 176   static bool   supports_monotonic_clock();
 177 
 178 
 179   // Returns the elapsed time in seconds since the vm started.
 180   static double elapsedTime();
 181 
 182   // Returns real time in seconds since an arbitrary point
 183   // in the past.
 184   static bool getTimesSecs(double* process_real_time,
 185                            double* process_user_time,
 186                            double* process_system_time);
 187 
 188   // Interface to the performance counter
 189   static jlong elapsed_counter();
 190   static jlong elapsed_frequency();
 191 
 192   // The "virtual time" of a thread is the amount of time a thread has
 193   // actually run.  The first function indicates whether the OS supports
 194   // this functionality for the current thread, and if so:
 195   //   * the second enables vtime tracking (if that is required).
 196   //   * the third tells whether vtime is enabled.
 197   //   * the fourth returns the elapsed virtual time for the current
 198   //     thread.
 199   static bool supports_vtime();
 200   static bool enable_vtime();
 201   static bool vtime_enabled();
 202   static double elapsedVTime();
 203 
 204   // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
 205   // It is MT safe, but not async-safe, as reading time zone
 206   // information may require a lock on some platforms.
 207   static char*      local_time_string(char *buf, size_t buflen);
 208   static struct tm* localtime_pd     (const time_t* clock, struct tm*  res);
 209   // Fill in buffer with current local time as an ISO-8601 string.
 210   // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
 211   // Returns buffer, or NULL if it failed.
 212   static char* iso8601_time(char* buffer, size_t buffer_length);
 213 
 214   // Interface for detecting multiprocessor system
 215   static inline bool is_MP() {
 216     // During bootstrap if _processor_count is not yet initialized
 217     // we claim to be MP as that is safest. If any platform has a
 218     // stub generator that might be triggered in this phase and for
 219     // which being declared MP when in fact not, is a problem - then
 220     // the bootstrap routine for the stub generator needs to check
 221     // the processor count directly and leave the bootstrap routine
 222     // in place until called after initialization has ocurred.
 223     return (_processor_count != 1) || AssumeMP;
 224   }
 225   static julong available_memory();
 226   static julong physical_memory();
 227   static bool has_allocatable_memory_limit(julong* limit);
 228   static bool is_server_class_machine();
 229 
 230   // number of CPUs
 231   static int processor_count() {
 232     return _processor_count;
 233   }
 234   static void set_processor_count(int count) { _processor_count = count; }
 235 
 236   // Returns the number of CPUs this process is currently allowed to run on.
 237   // Note that on some OSes this can change dynamically.
 238   static int active_processor_count();
 239 
 240   // Bind processes to processors.
 241   //     This is a two step procedure:
 242   //     first you generate a distribution of processes to processors,
 243   //     then you bind processes according to that distribution.
 244   // Compute a distribution for number of processes to processors.
 245   //    Stores the processor id's into the distribution array argument.
 246   //    Returns true if it worked, false if it didn't.
 247   static bool distribute_processes(uint length, uint* distribution);
 248   // Binds the current process to a processor.
 249   //    Returns true if it worked, false if it didn't.
 250   static bool bind_to_processor(uint processor_id);
 251 
 252   // Give a name to the current thread.
 253   static void set_native_thread_name(const char *name);
 254 
 255   // Interface for stack banging (predetect possible stack overflow for
 256   // exception processing)  There are guard pages, and above that shadow
 257   // pages for stack overflow checking.
 258   static bool uses_stack_guard_pages();
 259   static bool allocate_stack_guard_pages();
 260   static void bang_stack_shadow_pages();
 261   static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
 262 
 263   // OS interface to Virtual Memory
 264 
 265   // Return the default page size.
 266   static int    vm_page_size();
 267 
 268   // Returns the page size to use for a region of memory.
 269   // region_size / min_pages will always be greater than or equal to the
 270   // returned value.
 271   static size_t page_size_for_region(size_t region_size, size_t min_pages);
 272 
 273   // Return the largest page size that can be used
 274   static size_t max_page_size() {
 275     // The _page_sizes array is sorted in descending order.
 276     return _page_sizes[0];
 277   }
 278 
 279   // Methods for tracing page sizes returned by the above method; enabled by
 280   // TracePageSizes.  The region_{min,max}_size parameters should be the values
 281   // passed to page_size_for_region() and page_size should be the result of that
 282   // call.  The (optional) base and size parameters should come from the
 283   // ReservedSpace base() and size() methods.
 284   static void trace_page_sizes(const char* str, const size_t* page_sizes,
 285                                int count) PRODUCT_RETURN;
 286   static void trace_page_sizes(const char* str, const size_t region_min_size,
 287                                const size_t region_max_size,
 288                                const size_t page_size,
 289                                const char* base = NULL,
 290                                const size_t size = 0) PRODUCT_RETURN;
 291 
 292   static int    vm_allocation_granularity();
 293   static char*  reserve_memory(size_t bytes, char* addr = 0,
 294                                size_t alignment_hint = 0);
 295   static char*  reserve_memory(size_t bytes, char* addr,
 296                                size_t alignment_hint, MEMFLAGS flags);
 297   static char*  reserve_memory_aligned(size_t size, size_t alignment);
 298   static char*  attempt_reserve_memory_at(size_t bytes, char* addr);
 299   static void   split_reserved_memory(char *base, size_t size,
 300                                       size_t split, bool realloc);
 301   static bool   commit_memory(char* addr, size_t bytes, bool executable);
 302   static bool   commit_memory(char* addr, size_t size, size_t alignment_hint,
 303                               bool executable);
 304   // Same as commit_memory() that either succeeds or calls
 305   // vm_exit_out_of_memory() with the specified mesg.
 306   static void   commit_memory_or_exit(char* addr, size_t bytes,
 307                                       bool executable, const char* mesg);
 308   static void   commit_memory_or_exit(char* addr, size_t size,
 309                                       size_t alignment_hint,
 310                                       bool executable, const char* mesg);
 311   static bool   uncommit_memory(char* addr, size_t bytes);
 312   static bool   release_memory(char* addr, size_t bytes);
 313 






 314   enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
 315   static bool   protect_memory(char* addr, size_t bytes, ProtType prot,
 316                                bool is_committed = true);
 317 
 318   static bool   guard_memory(char* addr, size_t bytes);
 319   static bool   unguard_memory(char* addr, size_t bytes);
 320   static bool   create_stack_guard_pages(char* addr, size_t bytes);
 321   static bool   pd_create_stack_guard_pages(char* addr, size_t bytes);
 322   static bool   remove_stack_guard_pages(char* addr, size_t bytes);
 323 
 324   static char*  map_memory(int fd, const char* file_name, size_t file_offset,
 325                            char *addr, size_t bytes, bool read_only = false,
 326                            bool allow_exec = false);
 327   static char*  remap_memory(int fd, const char* file_name, size_t file_offset,
 328                              char *addr, size_t bytes, bool read_only,
 329                              bool allow_exec);
 330   static bool   unmap_memory(char *addr, size_t bytes);
 331   static void   free_memory(char *addr, size_t bytes, size_t alignment_hint);
 332   static void   realign_memory(char *addr, size_t bytes, size_t alignment_hint);
 333 
 334   // NUMA-specific interface
 335   static bool   numa_has_static_binding();
 336   static bool   numa_has_group_homing();
 337   static void   numa_make_local(char *addr, size_t bytes, int lgrp_hint);
 338   static void   numa_make_global(char *addr, size_t bytes);
 339   static size_t numa_get_groups_num();
 340   static size_t numa_get_leaf_groups(int *ids, size_t size);
 341   static bool   numa_topology_changed();
 342   static int    numa_get_group_id();
 343 
 344   // Page manipulation
 345   struct page_info {
 346     size_t size;
 347     int lgrp_id;
 348   };
 349   static bool   get_page_info(char *start, page_info* info);
 350   static char*  scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
 351 
 352   static char*  non_memory_address_word();
 353   // reserve, commit and pin the entire memory region
 354   static char*  reserve_memory_special(size_t size, size_t alignment,
 355                                        char* addr, bool executable);
 356   static bool   release_memory_special(char* addr, size_t bytes);
 357   static void   large_page_init();
 358   static size_t large_page_size();
 359   static bool   can_commit_large_page_memory();
 360   static bool   can_execute_large_page_memory();
 361 
 362   // OS interface to polling page
 363   static address get_polling_page()             { return _polling_page; }
 364   static void    set_polling_page(address page) { _polling_page = page; }
 365   static bool    is_poll_address(address addr)  { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
 366   static void    make_polling_page_unreadable();
 367   static void    make_polling_page_readable();
 368 
 369   // Routines used to serialize the thread state without using membars
 370   static void    serialize_thread_states();
 371 
 372   // Since we write to the serialize page from every thread, we
 373   // want stores to be on unique cache lines whenever possible
 374   // in order to minimize CPU cross talk.  We pre-compute the
 375   // amount to shift the thread* to make this offset unique to
 376   // each thread.
 377   static int     get_serialize_page_shift_count() {
 378     return SerializePageShiftCount;
 379   }
 380 
 381   static void     set_serialize_page_mask(uintptr_t mask) {
 382     _serialize_page_mask = mask;
 383   }
 384 
 385   static unsigned int  get_serialize_page_mask() {
 386     return _serialize_page_mask;
 387   }
 388 
 389   static void    set_memory_serialize_page(address page);
 390 
 391   static address get_memory_serialize_page() {
 392     return (address)_mem_serialize_page;
 393   }
 394 
 395   static inline void write_memory_serialize_page(JavaThread *thread) {
 396     uintptr_t page_offset = ((uintptr_t)thread >>
 397                             get_serialize_page_shift_count()) &
 398                             get_serialize_page_mask();
 399     *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
 400   }
 401 
 402   static bool    is_memory_serialize_page(JavaThread *thread, address addr) {
 403     if (UseMembar) return false;
 404     // Previously this function calculated the exact address of this
 405     // thread's serialize page, and checked if the faulting address
 406     // was equal.  However, some platforms mask off faulting addresses
 407     // to the page size, so now we just check that the address is
 408     // within the page.  This makes the thread argument unnecessary,
 409     // but we retain the NULL check to preserve existing behavior.
 410     if (thread == NULL) return false;
 411     address page = (address) _mem_serialize_page;
 412     return addr >= page && addr < (page + os::vm_page_size());
 413   }
 414 
 415   static void block_on_serialize_page_trap();
 416 
 417   // threads
 418 
 419   enum ThreadType {
 420     vm_thread,
 421     cgc_thread,        // Concurrent GC thread
 422     pgc_thread,        // Parallel GC thread
 423     java_thread,
 424     compiler_thread,
 425     watcher_thread,
 426     os_thread
 427   };
 428 
 429   static bool create_thread(Thread* thread,
 430                             ThreadType thr_type,
 431                             size_t stack_size = 0);
 432   static bool create_main_thread(JavaThread* thread);
 433   static bool create_attached_thread(JavaThread* thread);
 434   static void pd_start_thread(Thread* thread);
 435   static void start_thread(Thread* thread);
 436 
 437   static void initialize_thread(Thread* thr);
 438   static void free_thread(OSThread* osthread);
 439 
 440   // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
 441   static intx current_thread_id();
 442   static int current_process_id();
 443   static int sleep(Thread* thread, jlong ms, bool interruptable);
 444   // Short standalone OS sleep suitable for slow path spin loop.
 445   // Ignores Thread.interrupt() (so keep it short).
 446   // ms = 0, will sleep for the least amount of time allowed by the OS.
 447   static void naked_short_sleep(jlong ms);
 448   static void infinite_sleep(); // never returns, use with CAUTION
 449   static void naked_yield () ;
 450   static OSReturn set_priority(Thread* thread, ThreadPriority priority);
 451   static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
 452 
 453   static void interrupt(Thread* thread);
 454   static bool is_interrupted(Thread* thread, bool clear_interrupted);
 455 
 456   static int pd_self_suspend_thread(Thread* thread);
 457 
 458   static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
 459   static frame      fetch_frame_from_context(void* ucVoid);
 460 
 461   static ExtendedPC get_thread_pc(Thread *thread);
 462   static void breakpoint();
 463 
 464   static address current_stack_pointer();
 465   static address current_stack_base();
 466   static size_t current_stack_size();
 467 
 468   static void verify_stack_alignment() PRODUCT_RETURN;
 469 
 470   static int message_box(const char* title, const char* message);
 471   static char* do_you_want_to_debug(const char* message);
 472 
 473   // run cmd in a separate process and return its exit code; or -1 on failures
 474   static int fork_and_exec(char *cmd);
 475 
 476   // Call ::exit() on all platforms but Windows
 477   static void exit(int num);
 478 
 479   // Terminate the VM, but don't exit the process
 480   static void shutdown();
 481 
 482   // Terminate with an error.  Default is to generate a core file on platforms
 483   // that support such things.  This calls shutdown() and then aborts.
 484   static void abort(bool dump_core = true);
 485 
 486   // Die immediately, no exit hook, no abort hook, no cleanup.
 487   static void die();
 488 
 489   // File i/o operations
 490   static const int default_file_open_flags();
 491   static int open(const char *path, int oflag, int mode);
 492   static FILE* open(int fd, const char* mode);
 493   static int close(int fd);
 494   static jlong lseek(int fd, jlong offset, int whence);
 495   static char* native_path(char *path);
 496   static int ftruncate(int fd, jlong length);
 497   static int fsync(int fd);
 498   static int available(int fd, jlong *bytes);
 499 
 500   //File i/o operations
 501 
 502   static size_t read(int fd, void *buf, unsigned int nBytes);
 503   static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
 504   static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
 505   static size_t write(int fd, const void *buf, unsigned int nBytes);
 506 
 507   // Reading directories.
 508   static DIR*           opendir(const char* dirname);
 509   static int            readdir_buf_size(const char *path);
 510   static struct dirent* readdir(DIR* dirp, dirent* dbuf);
 511   static int            closedir(DIR* dirp);
 512 
 513   // Dynamic library extension
 514   static const char*    dll_file_extension();
 515 
 516   static const char*    get_temp_directory();
 517   static const char*    get_current_directory(char *buf, size_t buflen);
 518 
 519   // Builds a platform-specific full library path given a ld path and lib name
 520   // Returns true if buffer contains full path to existing file, false otherwise
 521   static bool           dll_build_name(char* buffer, size_t size,
 522                                        const char* pathname, const char* fname);
 523 
 524   // Symbol lookup, find nearest function name; basically it implements
 525   // dladdr() for all platforms. Name of the nearest function is copied
 526   // to buf. Distance from its base address is optionally returned as offset.
 527   // If function name is not found, buf[0] is set to '\0' and offset is
 528   // set to -1 (if offset is non-NULL).
 529   static bool dll_address_to_function_name(address addr, char* buf,
 530                                            int buflen, int* offset);
 531 
 532   // Locate DLL/DSO. On success, full path of the library is copied to
 533   // buf, and offset is optionally set to be the distance between addr
 534   // and the library's base address. On failure, buf[0] is set to '\0'
 535   // and offset is set to -1 (if offset is non-NULL).
 536   static bool dll_address_to_library_name(address addr, char* buf,
 537                                           int buflen, int* offset);
 538 
 539   // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
 540   static bool address_is_in_vm(address addr);
 541 
 542   // Loads .dll/.so and
 543   // in case of error it checks if .dll/.so was built for the
 544   // same architecture as HotSpot is running on
 545   static void* dll_load(const char *name, char *ebuf, int ebuflen);
 546 
 547   // lookup symbol in a shared library
 548   static void* dll_lookup(void* handle, const char* name);
 549 
 550   // Unload library
 551   static void  dll_unload(void *lib);
 552 
 553   // Callback for loaded module information
 554   // Input parameters:
 555   //    char*     module_file_name,
 556   //    address   module_base_addr,
 557   //    address   module_top_addr,
 558   //    void*     param
 559   typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
 560 
 561   static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
 562 
 563   // Return the handle of this process
 564   static void* get_default_process_handle();
 565 
 566   // Check for static linked agent library
 567   static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
 568                                  size_t syms_len);
 569 
 570   // Find agent entry point
 571   static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
 572                                    const char *syms[], size_t syms_len);
 573 
 574   // Print out system information; they are called by fatal error handler.
 575   // Output format may be different on different platforms.
 576   static void print_os_info(outputStream* st);
 577   static void print_os_info_brief(outputStream* st);
 578   static void print_cpu_info(outputStream* st);
 579   static void pd_print_cpu_info(outputStream* st);
 580   static void print_memory_info(outputStream* st);
 581   static void print_dll_info(outputStream* st);
 582   static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
 583   static void print_context(outputStream* st, void* context);
 584   static void print_register_info(outputStream* st, void* context);
 585   static void print_siginfo(outputStream* st, void* siginfo);
 586   static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
 587   static void print_date_and_time(outputStream* st);
 588 
 589   static void print_location(outputStream* st, intptr_t x, bool verbose = false);
 590   static size_t lasterror(char *buf, size_t len);
 591   static int get_last_error();
 592 
 593   // Determines whether the calling process is being debugged by a user-mode debugger.
 594   static bool is_debugger_attached();
 595 
 596   // wait for a key press if PauseAtExit is set
 597   static void wait_for_keypress_at_exit(void);
 598 
 599   // The following two functions are used by fatal error handler to trace
 600   // native (C) frames. They are not part of frame.hpp/frame.cpp because
 601   // frame.hpp/cpp assume thread is JavaThread, and also because different
 602   // OS/compiler may have different convention or provide different API to
 603   // walk C frames.
 604   //
 605   // We don't attempt to become a debugger, so we only follow frames if that
 606   // does not require a lookup in the unwind table, which is part of the binary
 607   // file but may be unsafe to read after a fatal error. So on x86, we can
 608   // only walk stack if %ebp is used as frame pointer; on ia64, it's not
 609   // possible to walk C stack without having the unwind table.
 610   static bool is_first_C_frame(frame *fr);
 611   static frame get_sender_for_C_frame(frame *fr);
 612 
 613   // return current frame. pc() and sp() are set to NULL on failure.
 614   static frame      current_frame();
 615 
 616   static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
 617 
 618   // returns a string to describe the exception/signal;
 619   // returns NULL if exception_code is not an OS exception/signal.
 620   static const char* exception_name(int exception_code, char* buf, size_t buflen);
 621 
 622   // Returns native Java library, loads if necessary
 623   static void*    native_java_library();
 624 
 625   // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
 626   static void     jvm_path(char *buf, jint buflen);
 627 
 628   // Returns true if we are running in a headless jre.
 629   static bool     is_headless_jre();
 630 
 631   // JNI names
 632   static void     print_jni_name_prefix_on(outputStream* st, int args_size);
 633   static void     print_jni_name_suffix_on(outputStream* st, int args_size);
 634 
 635   // Init os specific system properties values
 636   static void init_system_properties_values();
 637 
 638   // IO operations, non-JVM_ version.
 639   static int stat(const char* path, struct stat* sbuf);
 640   static bool dir_is_empty(const char* path);
 641 
 642   // IO operations on binary files
 643   static int create_binary_file(const char* path, bool rewrite_existing);
 644   static jlong current_file_offset(int fd);
 645   static jlong seek_to_file_offset(int fd, jlong offset);
 646 
 647   // Thread Local Storage
 648   static int   allocate_thread_local_storage();
 649   static void  thread_local_storage_at_put(int index, void* value);
 650   static void* thread_local_storage_at(int index);
 651   static void  free_thread_local_storage(int index);
 652 
 653   // Retrieve native stack frames.
 654   // Parameter:
 655   //   stack:  an array to storage stack pointers.
 656   //   frames: size of above array.
 657   //   toSkip: number of stack frames to skip at the beginning.
 658   // Return: number of stack frames captured.
 659   static int get_native_stack(address* stack, int size, int toSkip = 0);
 660 
 661   // General allocation (must be MT-safe)
 662   static void* malloc  (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
 663   static void* malloc  (size_t size, MEMFLAGS flags);
 664   static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
 665   static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
 666 
 667   static void  free    (void *memblock);
 668   static bool  check_heap(bool force = false);      // verify C heap integrity
 669   static char* strdup(const char *, MEMFLAGS flags = mtInternal);  // Like strdup
 670   // Like strdup, but exit VM when strdup() returns NULL
 671   static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
 672 
 673 #ifndef PRODUCT
 674   static julong num_mallocs;         // # of calls to malloc/realloc
 675   static julong alloc_bytes;         // # of bytes allocated
 676   static julong num_frees;           // # of calls to free
 677   static julong free_bytes;          // # of bytes freed
 678 #endif
 679 
 680   // SocketInterface (ex HPI SocketInterface )
 681   static int socket(int domain, int type, int protocol);
 682   static int socket_close(int fd);
 683   static int recv(int fd, char* buf, size_t nBytes, uint flags);
 684   static int send(int fd, char* buf, size_t nBytes, uint flags);
 685   static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
 686   static int connect(int fd, struct sockaddr* him, socklen_t len);
 687   static struct hostent* get_host_by_name(char* name);
 688 
 689   // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
 690   static void  signal_init();
 691   static void  signal_init_pd();
 692   static void  signal_notify(int signal_number);
 693   static void* signal(int signal_number, void* handler);
 694   static void  signal_raise(int signal_number);
 695   static int   signal_wait();
 696   static int   signal_lookup();
 697   static void* user_handler();
 698   static void  terminate_signal_thread();
 699   static int   sigexitnum_pd();
 700 
 701   // random number generation
 702   static long random();                    // return 32bit pseudorandom number
 703   static void init_random(long initval);   // initialize random sequence
 704 
 705   // Structured OS Exception support
 706   static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
 707 
 708   // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
 709   static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
 710 
 711   // Get the default path to the core file
 712   // Returns the length of the string
 713   static int get_core_path(char* buffer, size_t bufferSize);
 714 
 715   // JVMTI & JVM monitoring and management support
 716   // The thread_cpu_time() and current_thread_cpu_time() are only
 717   // supported if is_thread_cpu_time_supported() returns true.
 718   // They are not supported on Solaris T1.
 719 
 720   // Thread CPU Time - return the fast estimate on a platform
 721   // On Solaris - call gethrvtime (fast) - user time only
 722   // On Linux   - fast clock_gettime where available - user+sys
 723   //            - otherwise: very slow /proc fs - user+sys
 724   // On Windows - GetThreadTimes - user+sys
 725   static jlong current_thread_cpu_time();
 726   static jlong thread_cpu_time(Thread* t);
 727 
 728   // Thread CPU Time with user_sys_cpu_time parameter.
 729   //
 730   // If user_sys_cpu_time is true, user+sys time is returned.
 731   // Otherwise, only user time is returned
 732   static jlong current_thread_cpu_time(bool user_sys_cpu_time);
 733   static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
 734 
 735   // Return a bunch of info about the timers.
 736   // Note that the returned info for these two functions may be different
 737   // on some platforms
 738   static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
 739   static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
 740 
 741   static bool is_thread_cpu_time_supported();
 742 
 743   // System loadavg support.  Returns -1 if load average cannot be obtained.
 744   static int loadavg(double loadavg[], int nelem);
 745 
 746   // Hook for os specific jvm options that we don't want to abort on seeing
 747   static bool obsolete_option(const JavaVMOption *option);
 748 
 749   // Amount beyond the callee frame size that we bang the stack.
 750   static int extra_bang_size_in_bytes();
 751 
 752   // Extensions
 753 #include "runtime/os_ext.hpp"
 754 
 755  public:
 756   class CrashProtectionCallback : public StackObj {
 757   public:
 758     virtual void call() = 0;
 759   };
 760 
 761   // Platform dependent stuff
 762 #ifdef TARGET_OS_FAMILY_linux
 763 # include "os_linux.hpp"
 764 # include "os_posix.hpp"
 765 #endif
 766 #ifdef TARGET_OS_FAMILY_solaris
 767 # include "os_solaris.hpp"
 768 # include "os_posix.hpp"
 769 #endif
 770 #ifdef TARGET_OS_FAMILY_windows
 771 # include "os_windows.hpp"
 772 #endif
 773 #ifdef TARGET_OS_FAMILY_aix
 774 # include "os_aix.hpp"
 775 # include "os_posix.hpp"
 776 #endif
 777 #ifdef TARGET_OS_FAMILY_bsd
 778 # include "os_posix.hpp"
 779 # include "os_bsd.hpp"
 780 #endif
 781 #ifdef TARGET_OS_ARCH_linux_x86
 782 # include "os_linux_x86.hpp"
 783 #endif
 784 #ifdef TARGET_OS_ARCH_linux_sparc
 785 # include "os_linux_sparc.hpp"
 786 #endif
 787 #ifdef TARGET_OS_ARCH_linux_zero
 788 # include "os_linux_zero.hpp"
 789 #endif
 790 #ifdef TARGET_OS_ARCH_solaris_x86
 791 # include "os_solaris_x86.hpp"
 792 #endif
 793 #ifdef TARGET_OS_ARCH_solaris_sparc
 794 # include "os_solaris_sparc.hpp"
 795 #endif
 796 #ifdef TARGET_OS_ARCH_windows_x86
 797 # include "os_windows_x86.hpp"
 798 #endif
 799 #ifdef TARGET_OS_ARCH_linux_arm
 800 # include "os_linux_arm.hpp"
 801 #endif
 802 #ifdef TARGET_OS_ARCH_linux_ppc
 803 # include "os_linux_ppc.hpp"
 804 #endif
 805 #ifdef TARGET_OS_ARCH_aix_ppc
 806 # include "os_aix_ppc.hpp"
 807 #endif
 808 #ifdef TARGET_OS_ARCH_bsd_x86
 809 # include "os_bsd_x86.hpp"
 810 #endif
 811 #ifdef TARGET_OS_ARCH_bsd_zero
 812 # include "os_bsd_zero.hpp"
 813 #endif
 814 
 815 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
 816 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
 817 #endif
 818 
 819  public:
 820 #ifndef PLATFORM_PRINT_NATIVE_STACK
 821   // No platform-specific code for printing the native stack.
 822   static bool platform_print_native_stack(outputStream* st, void* context,
 823                                           char *buf, int buf_size) {
 824     return false;
 825   }
 826 #endif
 827 
 828   // debugging support (mostly used by debug.cpp but also fatal error handler)
 829   static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
 830 
 831   static bool dont_yield();                     // when true, JVM_Yield() is nop
 832   static void print_statistics();
 833 
 834   // Thread priority helpers (implemented in OS-specific part)
 835   static OSReturn set_native_priority(Thread* thread, int native_prio);
 836   static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
 837   static int java_to_os_priority[CriticalPriority + 1];
 838   // Hint to the underlying OS that a task switch would not be good.
 839   // Void return because it's a hint and can fail.
 840   static void hint_no_preempt();
 841   static const char* native_thread_creation_failed_msg() {
 842     return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
 843   }
 844 
 845   // Used at creation if requested by the diagnostic flag PauseAtStartup.
 846   // Causes the VM to wait until an external stimulus has been applied
 847   // (for Unix, that stimulus is a signal, for Windows, an external
 848   // ResumeThread call)
 849   static void pause();
 850 
 851   // Builds a platform dependent Agent_OnLoad_<libname> function name
 852   // which is used to find statically linked in agents.
 853   static char*  build_agent_function_name(const char *sym, const char *cname,
 854                                           bool is_absolute_path);
 855 
 856   class SuspendedThreadTaskContext {
 857   public:
 858     SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
 859     Thread* thread() const { return _thread; }
 860     void* ucontext() const { return _ucontext; }
 861   private:
 862     Thread* _thread;
 863     void* _ucontext;
 864   };
 865 
 866   class SuspendedThreadTask {
 867   public:
 868     SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
 869     virtual ~SuspendedThreadTask() {}
 870     void run();
 871     bool is_done() { return _done; }
 872     virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
 873   protected:
 874   private:
 875     void internal_do_task();
 876     Thread* _thread;
 877     bool _done;
 878   };
 879 
 880 #ifndef TARGET_OS_FAMILY_windows
 881   // Suspend/resume support
 882   // Protocol:
 883   //
 884   // a thread starts in SR_RUNNING
 885   //
 886   // SR_RUNNING can go to
 887   //   * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
 888   // SR_SUSPEND_REQUEST can go to
 889   //   * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
 890   //   * SR_SUSPENDED if the stopped thread receives the signal and switches state
 891   // SR_SUSPENDED can go to
 892   //   * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
 893   // SR_WAKEUP_REQUEST can go to
 894   //   * SR_RUNNING when the stopped thread receives the signal
 895   //   * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
 896   class SuspendResume {
 897    public:
 898     enum State {
 899       SR_RUNNING,
 900       SR_SUSPEND_REQUEST,
 901       SR_SUSPENDED,
 902       SR_WAKEUP_REQUEST
 903     };
 904 
 905   private:
 906     volatile State _state;
 907 
 908   private:
 909     /* try to switch state from state "from" to state "to"
 910      * returns the state set after the method is complete
 911      */
 912     State switch_state(State from, State to);
 913 
 914   public:
 915     SuspendResume() : _state(SR_RUNNING) { }
 916 
 917     State state() const { return _state; }
 918 
 919     State request_suspend() {
 920       return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
 921     }
 922 
 923     State cancel_suspend() {
 924       return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
 925     }
 926 
 927     State suspended() {
 928       return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
 929     }
 930 
 931     State request_wakeup() {
 932       return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
 933     }
 934 
 935     State running() {
 936       return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
 937     }
 938 
 939     bool is_running() const {
 940       return _state == SR_RUNNING;
 941     }
 942 
 943     bool is_suspend_request() const {
 944       return _state == SR_SUSPEND_REQUEST;
 945     }
 946 
 947     bool is_suspended() const {
 948       return _state == SR_SUSPENDED;
 949     }
 950   };
 951 #endif
 952 
 953 
 954  protected:
 955   static long _rand_seed;                   // seed for random number generator
 956   static int _processor_count;              // number of processors
 957 
 958   static char* format_boot_path(const char* format_string,
 959                                 const char* home,
 960                                 int home_len,
 961                                 char fileSep,
 962                                 char pathSep);
 963   static bool set_boot_path(char fileSep, char pathSep);
 964   static char** split_path(const char* path, int* n);
 965 
 966 };
 967 
 968 // Note that "PAUSE" is almost always used with synchronization
 969 // so arguably we should provide Atomic::SpinPause() instead
 970 // of the global SpinPause() with C linkage.
 971 // It'd also be eligible for inlining on many platforms.
 972 
 973 extern "C" int SpinPause();
 974 
 975 #endif // SHARE_VM_RUNTIME_OS_HPP
--- EOF ---