1 /*
   2  * Copyright (c) 1997, 2011, 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/atomic.hpp"
  30 #include "runtime/extendedPC.hpp"
  31 #include "runtime/handles.hpp"
  32 #include "utilities/top.hpp"
  33 #ifdef TARGET_OS_FAMILY_linux
  34 # include "jvm_linux.h"
  35 #endif
  36 #ifdef TARGET_OS_FAMILY_solaris
  37 # include "jvm_solaris.h"
  38 #endif
  39 #ifdef TARGET_OS_FAMILY_windows
  40 # include "jvm_windows.h"
  41 #endif
  42 #ifdef TARGET_OS_FAMILY_bsd
  43 # include "jvm_bsd.h"
  44 #endif
  45 
  46 // os defines the interface to operating system; this includes traditional
  47 // OS services (time, I/O) as well as other functionality with system-
  48 // dependent code.
  49 
  50 typedef void (*dll_func)(...);
  51 
  52 class Thread;
  53 class JavaThread;
  54 class Event;
  55 class DLL;
  56 class FileHandle;
  57 template<class E> class GrowableArray;
  58 
  59 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
  60 
  61 // Platform-independent error return values from OS functions
  62 enum OSReturn {
  63   OS_OK         =  0,        // Operation was successful
  64   OS_ERR        = -1,        // Operation failed
  65   OS_INTRPT     = -2,        // Operation was interrupted
  66   OS_TIMEOUT    = -3,        // Operation timed out
  67   OS_NOMEM      = -5,        // Operation failed for lack of memory
  68   OS_NORESOURCE = -6         // Operation failed for lack of nonmemory resource
  69 };
  70 
  71 enum ThreadPriority {        // JLS 20.20.1-3
  72   NoPriority       = -1,     // Initial non-priority value
  73   MinPriority      =  1,     // Minimum priority
  74   NormPriority     =  5,     // Normal (non-daemon) priority
  75   NearMaxPriority  =  9,     // High priority, used for VMThread
  76   MaxPriority      = 10,     // Highest priority, used for WatcherThread
  77                              // ensures that VMThread doesn't starve profiler
  78   CriticalPriority = 11      // Critical thread priority
  79 };
  80 
  81 // Typedef for structured exception handling support
  82 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
  83 
  84 class os: AllStatic {
  85  public:
  86   enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
  87 
  88  private:
  89   static OSThread*          _starting_thread;
  90   static address            _polling_page;
  91   static volatile int32_t * _mem_serialize_page;
  92   static uintptr_t          _serialize_page_mask;
  93  public:
  94   static size_t             _page_sizes[page_sizes_max];
  95 
  96  private:
  97   static void init_page_sizes(size_t default_page_size) {
  98     _page_sizes[0] = default_page_size;
  99     _page_sizes[1] = 0; // sentinel
 100   }
 101 
 102  public:
 103   static void init(void);                      // Called before command line parsing
 104   static jint init_2(void);                    // Called after command line parsing
 105   static void init_globals(void) {             // Called from init_globals() in init.cpp
 106     init_globals_ext();
 107   }
 108   static void init_3(void);                    // Called at the end of vm init
 109 
 110   // File names are case-insensitive on windows only
 111   // Override me as needed
 112   static int    file_name_strcmp(const char* s1, const char* s2);
 113 
 114   static bool getenv(const char* name, char* buffer, int len);
 115   static bool have_special_privileges();
 116 
 117   static jlong  javaTimeMillis();
 118   static jlong  javaTimeNanos();
 119   static void   javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
 120   static void   run_periodic_checks();
 121 
 122 
 123   // Returns the elapsed time in seconds since the vm started.
 124   static double elapsedTime();
 125 
 126   // Returns real time in seconds since an arbitrary point
 127   // in the past.
 128   static bool getTimesSecs(double* process_real_time,
 129                            double* process_user_time,
 130                            double* process_system_time);
 131 
 132   // Interface to the performance counter
 133   static jlong elapsed_counter();
 134   static jlong elapsed_frequency();
 135 
 136   // The "virtual time" of a thread is the amount of time a thread has
 137   // actually run.  The first function indicates whether the OS supports
 138   // this functionality for the current thread, and if so:
 139   //   * the second enables vtime tracking (if that is required).
 140   //   * the third tells whether vtime is enabled.
 141   //   * the fourth returns the elapsed virtual time for the current
 142   //     thread.
 143   static bool supports_vtime();
 144   static bool enable_vtime();
 145   static bool vtime_enabled();
 146   static double elapsedVTime();
 147 
 148   // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
 149   // It is MT safe, but not async-safe, as reading time zone
 150   // information may require a lock on some platforms.
 151   static char*      local_time_string(char *buf, size_t buflen);
 152   static struct tm* localtime_pd     (const time_t* clock, struct tm*  res);
 153   // Fill in buffer with current local time as an ISO-8601 string.
 154   // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
 155   // Returns buffer, or NULL if it failed.
 156   static char* iso8601_time(char* buffer, size_t buffer_length);
 157 
 158   // Interface for detecting multiprocessor system
 159   static inline bool is_MP() {
 160     assert(_processor_count > 0, "invalid processor count");
 161     return _processor_count > 1;
 162   }
 163   static julong available_memory();
 164   static julong physical_memory();
 165   static julong allocatable_physical_memory(julong size);
 166   static bool is_server_class_machine();
 167 
 168   // number of CPUs
 169   static int processor_count() {
 170     return _processor_count;
 171   }
 172   static void set_processor_count(int count) { _processor_count = count; }
 173 
 174   // Returns the number of CPUs this process is currently allowed to run on.
 175   // Note that on some OSes this can change dynamically.
 176   static int active_processor_count();
 177 
 178   // Bind processes to processors.
 179   //     This is a two step procedure:
 180   //     first you generate a distribution of processes to processors,
 181   //     then you bind processes according to that distribution.
 182   // Compute a distribution for number of processes to processors.
 183   //    Stores the processor id's into the distribution array argument.
 184   //    Returns true if it worked, false if it didn't.
 185   static bool distribute_processes(uint length, uint* distribution);
 186   // Binds the current process to a processor.
 187   //    Returns true if it worked, false if it didn't.
 188   static bool bind_to_processor(uint processor_id);
 189 
 190   // Give a name to the current thread.
 191   static void set_native_thread_name(const char *name);
 192 
 193   // Interface for stack banging (predetect possible stack overflow for
 194   // exception processing)  There are guard pages, and above that shadow
 195   // pages for stack overflow checking.
 196   static bool uses_stack_guard_pages();
 197   static bool allocate_stack_guard_pages();
 198   static void bang_stack_shadow_pages();
 199   static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
 200 
 201   // OS interface to Virtual Memory
 202 
 203   // Return the default page size.
 204   static int    vm_page_size();
 205 
 206   // Return the page size to use for a region of memory.  The min_pages argument
 207   // is a hint intended to limit fragmentation; it says the returned page size
 208   // should be <= region_max_size / min_pages.  Because min_pages is a hint,
 209   // this routine may return a size larger than region_max_size / min_pages.
 210   //
 211   // The current implementation ignores min_pages if a larger page size is an
 212   // exact multiple of both region_min_size and region_max_size.  This allows
 213   // larger pages to be used when doing so would not cause fragmentation; in
 214   // particular, a single page can be used when region_min_size ==
 215   // region_max_size == a supported page size.
 216   static size_t page_size_for_region(size_t region_min_size,
 217                                      size_t region_max_size,
 218                                      uint min_pages);
 219 
 220   // Methods for tracing page sizes returned by the above method; enabled by
 221   // TracePageSizes.  The region_{min,max}_size parameters should be the values
 222   // passed to page_size_for_region() and page_size should be the result of that
 223   // call.  The (optional) base and size parameters should come from the
 224   // ReservedSpace base() and size() methods.
 225   static void trace_page_sizes(const char* str, const size_t* page_sizes,
 226                                int count) PRODUCT_RETURN;
 227   static void trace_page_sizes(const char* str, const size_t region_min_size,
 228                                const size_t region_max_size,
 229                                const size_t page_size,
 230                                const char* base = NULL,
 231                                const size_t size = 0) PRODUCT_RETURN;
 232 
 233   static int    vm_allocation_granularity();
 234   static char*  reserve_memory(size_t bytes, char* addr = 0,
 235                                size_t alignment_hint = 0);
 236   static char*  attempt_reserve_memory_at(size_t bytes, char* addr);
 237   static void   split_reserved_memory(char *base, size_t size,
 238                                       size_t split, bool realloc);
 239   static bool   commit_memory(char* addr, size_t bytes,
 240                               bool executable = false);
 241   static bool   commit_memory(char* addr, size_t size, size_t alignment_hint,
 242                               bool executable = false);
 243   static bool   uncommit_memory(char* addr, size_t bytes);
 244   static bool   release_memory(char* addr, size_t bytes);
 245 
 246   enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
 247   static bool   protect_memory(char* addr, size_t bytes, ProtType prot,
 248                                bool is_committed = true);
 249 
 250   static bool   guard_memory(char* addr, size_t bytes);
 251   static bool   unguard_memory(char* addr, size_t bytes);
 252   static bool   create_stack_guard_pages(char* addr, size_t bytes);
 253   static bool   remove_stack_guard_pages(char* addr, size_t bytes);
 254 
 255   static char*  map_memory(int fd, const char* file_name, size_t file_offset,
 256                            char *addr, size_t bytes, bool read_only = false,
 257                            bool allow_exec = false);
 258   static char*  remap_memory(int fd, const char* file_name, size_t file_offset,
 259                              char *addr, size_t bytes, bool read_only,
 260                              bool allow_exec);
 261   static bool   unmap_memory(char *addr, size_t bytes);
 262   static void   free_memory(char *addr, size_t bytes, size_t alignment_hint);
 263   static void   realign_memory(char *addr, size_t bytes, size_t alignment_hint);
 264 
 265   // NUMA-specific interface
 266   static bool   numa_has_static_binding();
 267   static bool   numa_has_group_homing();
 268   static void   numa_make_local(char *addr, size_t bytes, int lgrp_hint);
 269   static void   numa_make_global(char *addr, size_t bytes);
 270   static size_t numa_get_groups_num();
 271   static size_t numa_get_leaf_groups(int *ids, size_t size);
 272   static bool   numa_topology_changed();
 273   static int    numa_get_group_id();
 274 
 275   // Page manipulation
 276   struct page_info {
 277     size_t size;
 278     int lgrp_id;
 279   };
 280   static bool   get_page_info(char *start, page_info* info);
 281   static char*  scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
 282 
 283   static char*  non_memory_address_word();
 284   // reserve, commit and pin the entire memory region
 285   static char*  reserve_memory_special(size_t size, char* addr = NULL,
 286                 bool executable = false);
 287   static bool   release_memory_special(char* addr, size_t bytes);
 288   static void   large_page_init();
 289   static size_t large_page_size();
 290   static bool   can_commit_large_page_memory();
 291   static bool   can_execute_large_page_memory();
 292 
 293   // OS interface to polling page
 294   static address get_polling_page()             { return _polling_page; }
 295   static void    set_polling_page(address page) { _polling_page = page; }
 296   static bool    is_poll_address(address addr)  { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
 297   static void    make_polling_page_unreadable();
 298   static void    make_polling_page_readable();
 299 
 300   // Routines used to serialize the thread state without using membars
 301   static void    serialize_thread_states();
 302 
 303   // Since we write to the serialize page from every thread, we
 304   // want stores to be on unique cache lines whenever possible
 305   // in order to minimize CPU cross talk.  We pre-compute the
 306   // amount to shift the thread* to make this offset unique to
 307   // each thread.
 308   static int     get_serialize_page_shift_count() {
 309     return SerializePageShiftCount;
 310   }
 311 
 312   static void     set_serialize_page_mask(uintptr_t mask) {
 313     _serialize_page_mask = mask;
 314   }
 315 
 316   static unsigned int  get_serialize_page_mask() {
 317     return _serialize_page_mask;
 318   }
 319 
 320   static void    set_memory_serialize_page(address page);
 321 
 322   static address get_memory_serialize_page() {
 323     return (address)_mem_serialize_page;
 324   }
 325 
 326   static inline void write_memory_serialize_page(JavaThread *thread) {
 327     uintptr_t page_offset = ((uintptr_t)thread >>
 328                             get_serialize_page_shift_count()) &
 329                             get_serialize_page_mask();
 330     *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
 331   }
 332 
 333   static bool    is_memory_serialize_page(JavaThread *thread, address addr) {
 334     if (UseMembar) return false;
 335     // Previously this function calculated the exact address of this
 336     // thread's serialize page, and checked if the faulting address
 337     // was equal.  However, some platforms mask off faulting addresses
 338     // to the page size, so now we just check that the address is
 339     // within the page.  This makes the thread argument unnecessary,
 340     // but we retain the NULL check to preserve existing behaviour.
 341     if (thread == NULL) return false;
 342     address page = (address) _mem_serialize_page;
 343     return addr >= page && addr < (page + os::vm_page_size());
 344   }
 345 
 346   static void block_on_serialize_page_trap();
 347 
 348   // threads
 349 
 350   enum ThreadType {
 351     vm_thread,
 352     cgc_thread,        // Concurrent GC thread
 353     pgc_thread,        // Parallel GC thread
 354     java_thread,
 355     compiler_thread,
 356     watcher_thread,
 357     os_thread
 358   };
 359 
 360   static bool create_thread(Thread* thread,
 361                             ThreadType thr_type,
 362                             size_t stack_size = 0);
 363   static bool create_main_thread(JavaThread* thread);
 364   static bool create_attached_thread(JavaThread* thread);
 365   static void pd_start_thread(Thread* thread);
 366   static void start_thread(Thread* thread);
 367 
 368   static void initialize_thread();
 369   static void free_thread(OSThread* osthread);
 370 
 371   // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
 372   static intx current_thread_id();
 373   static int current_process_id();
 374   static int sleep(Thread* thread, jlong ms, bool interruptable);
 375   static int naked_sleep();
 376   static void infinite_sleep(); // never returns, use with CAUTION
 377   static void yield();        // Yields to all threads with same priority
 378   enum YieldResult {
 379     YIELD_SWITCHED = 1,         // caller descheduled, other ready threads exist & ran
 380     YIELD_NONEREADY = 0,        // No other runnable/ready threads.
 381                                 // platform-specific yield return immediately
 382     YIELD_UNKNOWN = -1          // Unknown: platform doesn't support _SWITCHED or _NONEREADY
 383     // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
 384     // yield that can be used in lieu of blocking.
 385   } ;
 386   static YieldResult NakedYield () ;
 387   static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
 388   static void loop_breaker(int attempts);  // called from within tight loops to possibly influence time-sharing
 389   static OSReturn set_priority(Thread* thread, ThreadPriority priority);
 390   static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
 391 
 392   static void interrupt(Thread* thread);
 393   static bool is_interrupted(Thread* thread, bool clear_interrupted);
 394 
 395   static int pd_self_suspend_thread(Thread* thread);
 396 
 397   static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
 398   static frame      fetch_frame_from_context(void* ucVoid);
 399 
 400   static ExtendedPC get_thread_pc(Thread *thread);
 401   static void breakpoint();
 402 
 403   static address current_stack_pointer();
 404   static address current_stack_base();
 405   static size_t current_stack_size();
 406 
 407   static int message_box(const char* title, const char* message);
 408   static char* do_you_want_to_debug(const char* message);
 409 
 410   // run cmd in a separate process and return its exit code; or -1 on failures
 411   static int fork_and_exec(char *cmd);
 412 
 413   // Set file to send error reports.
 414   static void set_error_file(const char *logfile);
 415 
 416   // os::exit() is merged with vm_exit()
 417   // static void exit(int num);
 418 
 419   // Terminate the VM, but don't exit the process
 420   static void shutdown();
 421 
 422   // Terminate with an error.  Default is to generate a core file on platforms
 423   // that support such things.  This calls shutdown() and then aborts.
 424   static void abort(bool dump_core = true);
 425 
 426   // Die immediately, no exit hook, no abort hook, no cleanup.
 427   static void die();
 428 
 429   // File i/o operations
 430   static const int default_file_open_flags();
 431   static int open(const char *path, int oflag, int mode);
 432   static int close(int fd);
 433   static jlong lseek(int fd, jlong offset, int whence);
 434   static char* native_path(char *path);
 435   static int ftruncate(int fd, jlong length);
 436   static int fsync(int fd);
 437   static int available(int fd, jlong *bytes);
 438 
 439   //File i/o operations
 440 
 441   static size_t read(int fd, void *buf, unsigned int nBytes);
 442   static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
 443   static size_t write(int fd, const void *buf, unsigned int nBytes);
 444 
 445   // Reading directories.
 446   static DIR*           opendir(const char* dirname);
 447   static int            readdir_buf_size(const char *path);
 448   static struct dirent* readdir(DIR* dirp, dirent* dbuf);
 449   static int            closedir(DIR* dirp);
 450 
 451   // Dynamic library extension
 452   static const char*    dll_file_extension();
 453 
 454   static const char*    get_temp_directory();
 455   static const char*    get_current_directory(char *buf, int buflen);
 456 
 457   // Builds a platform-specific full library path given a ld path and lib name
 458   static void           dll_build_name(char* buffer, size_t size,
 459                                        const char* pathname, const char* fname);
 460 
 461   // Symbol lookup, find nearest function name; basically it implements
 462   // dladdr() for all platforms. Name of the nearest function is copied
 463   // to buf. Distance from its base address is returned as offset.
 464   // If function name is not found, buf[0] is set to '\0' and offset is
 465   // set to -1.
 466   static bool dll_address_to_function_name(address addr, char* buf,
 467                                            int buflen, int* offset);
 468 
 469   // Locate DLL/DSO. On success, full path of the library is copied to
 470   // buf, and offset is set to be the distance between addr and the
 471   // library's base address. On failure, buf[0] is set to '\0' and
 472   // offset is set to -1.
 473   static bool dll_address_to_library_name(address addr, char* buf,
 474                                           int buflen, int* offset);
 475 
 476   // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
 477   static bool address_is_in_vm(address addr);
 478 
 479   // Loads .dll/.so and
 480   // in case of error it checks if .dll/.so was built for the
 481   // same architecture as Hotspot is running on
 482   static void* dll_load(const char *name, char *ebuf, int ebuflen);
 483 
 484   // lookup symbol in a shared library
 485   static void* dll_lookup(void* handle, const char* name);
 486 
 487   // Unload library
 488   static void  dll_unload(void *lib);
 489 
 490   // Print out system information; they are called by fatal error handler.
 491   // Output format may be different on different platforms.
 492   static void print_os_info(outputStream* st);
 493   static void print_cpu_info(outputStream* st);
 494   static void pd_print_cpu_info(outputStream* st);
 495   static void print_memory_info(outputStream* st);
 496   static void print_dll_info(outputStream* st);
 497   static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
 498   static void print_context(outputStream* st, void* context);
 499   static void print_register_info(outputStream* st, void* context);
 500   static void print_siginfo(outputStream* st, void* siginfo);
 501   static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
 502   static void print_date_and_time(outputStream* st);
 503 
 504   static void print_location(outputStream* st, intptr_t x, bool verbose = false);
 505   static size_t lasterror(char *buf, size_t len);
 506   static int get_last_error();
 507 
 508   // Determines whether the calling process is being debugged by a user-mode debugger.
 509   static bool is_debugger_attached();
 510 
 511   // wait for a key press if PauseAtExit is set
 512   static void wait_for_keypress_at_exit(void);
 513 
 514   // The following two functions are used by fatal error handler to trace
 515   // native (C) frames. They are not part of frame.hpp/frame.cpp because
 516   // frame.hpp/cpp assume thread is JavaThread, and also because different
 517   // OS/compiler may have different convention or provide different API to
 518   // walk C frames.
 519   //
 520   // We don't attempt to become a debugger, so we only follow frames if that
 521   // does not require a lookup in the unwind table, which is part of the binary
 522   // file but may be unsafe to read after a fatal error. So on x86, we can
 523   // only walk stack if %ebp is used as frame pointer; on ia64, it's not
 524   // possible to walk C stack without having the unwind table.
 525   static bool is_first_C_frame(frame *fr);
 526   static frame get_sender_for_C_frame(frame *fr);
 527 
 528   // return current frame. pc() and sp() are set to NULL on failure.
 529   static frame      current_frame();
 530 
 531   static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
 532 
 533   // returns a string to describe the exception/signal;
 534   // returns NULL if exception_code is not an OS exception/signal.
 535   static const char* exception_name(int exception_code, char* buf, size_t buflen);
 536 
 537   // Returns native Java library, loads if necessary
 538   static void*    native_java_library();
 539 
 540   // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
 541   static void     jvm_path(char *buf, jint buflen);
 542 
 543   // Returns true if we are running in a headless jre.
 544   static bool     is_headless_jre();
 545 
 546   // JNI names
 547   static void     print_jni_name_prefix_on(outputStream* st, int args_size);
 548   static void     print_jni_name_suffix_on(outputStream* st, int args_size);
 549 
 550   // File conventions
 551   static const char* file_separator();
 552   static const char* line_separator();
 553   static const char* path_separator();
 554 
 555   // Init os specific system properties values
 556   static void init_system_properties_values();
 557 
 558   // IO operations, non-JVM_ version.
 559   static int stat(const char* path, struct stat* sbuf);
 560   static bool dir_is_empty(const char* path);
 561 
 562   // IO operations on binary files
 563   static int create_binary_file(const char* path, bool rewrite_existing);
 564   static jlong current_file_offset(int fd);
 565   static jlong seek_to_file_offset(int fd, jlong offset);
 566 
 567   // Thread Local Storage
 568   static int   allocate_thread_local_storage();
 569   static void  thread_local_storage_at_put(int index, void* value);
 570   static void* thread_local_storage_at(int index);
 571   static void  free_thread_local_storage(int index);
 572 
 573   // General allocation (must be MT-safe)
 574   static void* malloc  (size_t size);
 575   static void* realloc (void *memblock, size_t size);
 576   static void  free    (void *memblock);
 577   static bool  check_heap(bool force = false);      // verify C heap integrity
 578   static char* strdup(const char *);  // Like strdup
 579 
 580 #ifndef PRODUCT
 581   static julong num_mallocs;         // # of calls to malloc/realloc
 582   static julong alloc_bytes;         // # of bytes allocated
 583   static julong num_frees;           // # of calls to free
 584   static julong free_bytes;          // # of bytes freed
 585 #endif
 586 
 587   // SocketInterface (ex HPI SocketInterface )
 588   static int socket(int domain, int type, int protocol);
 589   static int socket_close(int fd);
 590   static int socket_shutdown(int fd, int howto);
 591   static int recv(int fd, char* buf, size_t nBytes, uint flags);
 592   static int send(int fd, char* buf, size_t nBytes, uint flags);
 593   static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
 594   static int timeout(int fd, long timeout);
 595   static int listen(int fd, int count);
 596   static int connect(int fd, struct sockaddr* him, socklen_t len);
 597   static int bind(int fd, struct sockaddr* him, socklen_t len);
 598   static int accept(int fd, struct sockaddr* him, socklen_t* len);
 599   static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
 600                       struct sockaddr* from, socklen_t* fromlen);
 601   static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
 602   static int sendto(int fd, char* buf, size_t len, uint flags,
 603                     struct sockaddr* to, socklen_t tolen);
 604   static int socket_available(int fd, jint* pbytes);
 605 
 606   static int get_sock_opt(int fd, int level, int optname,
 607                           char* optval, socklen_t* optlen);
 608   static int set_sock_opt(int fd, int level, int optname,
 609                           const char* optval, socklen_t optlen);
 610   static int get_host_name(char* name, int namelen);
 611 
 612   static struct hostent* get_host_by_name(char* name);
 613 
 614   // Printing 64 bit integers
 615   static const char* jlong_format_specifier();
 616   static const char* julong_format_specifier();
 617 
 618   // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
 619   static void  signal_init();
 620   static void  signal_init_pd();
 621   static void  signal_notify(int signal_number);
 622   static void* signal(int signal_number, void* handler);
 623   static void  signal_raise(int signal_number);
 624   static int   signal_wait();
 625   static int   signal_lookup();
 626   static void* user_handler();
 627   static void  terminate_signal_thread();
 628   static int   sigexitnum_pd();
 629 
 630   // random number generation
 631   static long random();                    // return 32bit pseudorandom number
 632   static void init_random(long initval);   // initialize random sequence
 633 
 634   // Structured OS Exception support
 635   static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
 636 
 637   // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
 638   static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
 639 
 640   // JVMTI & JVM monitoring and management support
 641   // The thread_cpu_time() and current_thread_cpu_time() are only
 642   // supported if is_thread_cpu_time_supported() returns true.
 643   // They are not supported on Solaris T1.
 644 
 645   // Thread CPU Time - return the fast estimate on a platform
 646   // On Solaris - call gethrvtime (fast) - user time only
 647   // On Linux   - fast clock_gettime where available - user+sys
 648   //            - otherwise: very slow /proc fs - user+sys
 649   // On Windows - GetThreadTimes - user+sys
 650   static jlong current_thread_cpu_time();
 651   static jlong thread_cpu_time(Thread* t);
 652 
 653   // Thread CPU Time with user_sys_cpu_time parameter.
 654   //
 655   // If user_sys_cpu_time is true, user+sys time is returned.
 656   // Otherwise, only user time is returned
 657   static jlong current_thread_cpu_time(bool user_sys_cpu_time);
 658   static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
 659 
 660   // Return a bunch of info about the timers.
 661   // Note that the returned info for these two functions may be different
 662   // on some platforms
 663   static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
 664   static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
 665 
 666   static bool is_thread_cpu_time_supported();
 667 
 668   // System loadavg support.  Returns -1 if load average cannot be obtained.
 669   static int loadavg(double loadavg[], int nelem);
 670 
 671   // Hook for os specific jvm options that we don't want to abort on seeing
 672   static bool obsolete_option(const JavaVMOption *option);
 673 
 674   // Read file line by line. If line is longer than bsize,
 675   // rest of line is skipped. Returns number of bytes read or -1 on EOF
 676   static int get_line_chars(int fd, char *buf, const size_t bsize);
 677 
 678   // Extensions
 679 #include "runtime/os_ext.hpp"
 680 
 681  public:
 682 
 683   // Platform dependent stuff
 684 #ifdef TARGET_OS_FAMILY_linux
 685 # include "os_linux.hpp"
 686 #endif
 687 #ifdef TARGET_OS_FAMILY_solaris
 688 # include "os_solaris.hpp"
 689 #endif
 690 #ifdef TARGET_OS_FAMILY_windows
 691 # include "os_windows.hpp"
 692 #endif
 693 #ifdef TARGET_OS_FAMILY_bsd
 694 # include "os_bsd.hpp"
 695 #endif
 696 #ifdef TARGET_OS_ARCH_linux_x86
 697 # include "os_linux_x86.hpp"
 698 #endif
 699 #ifdef TARGET_OS_ARCH_linux_sparc
 700 # include "os_linux_sparc.hpp"
 701 #endif
 702 #ifdef TARGET_OS_ARCH_linux_zero
 703 # include "os_linux_zero.hpp"
 704 #endif
 705 #ifdef TARGET_OS_ARCH_solaris_x86
 706 # include "os_solaris_x86.hpp"
 707 #endif
 708 #ifdef TARGET_OS_ARCH_solaris_sparc
 709 # include "os_solaris_sparc.hpp"
 710 #endif
 711 #ifdef TARGET_OS_ARCH_windows_x86
 712 # include "os_windows_x86.hpp"
 713 #endif
 714 #ifdef TARGET_OS_ARCH_linux_arm
 715 # include "os_linux_arm.hpp"
 716 #endif
 717 #ifdef TARGET_OS_ARCH_linux_ppc
 718 # include "os_linux_ppc.hpp"
 719 #endif
 720 #ifdef TARGET_OS_ARCH_bsd_x86
 721 # include "os_bsd_x86.hpp"
 722 #endif
 723 #ifdef TARGET_OS_ARCH_bsd_zero
 724 # include "os_bsd_zero.hpp"
 725 #endif
 726 
 727  public:
 728   // debugging support (mostly used by debug.cpp but also fatal error handler)
 729   static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
 730 
 731   static bool dont_yield();                     // when true, JVM_Yield() is nop
 732   static void print_statistics();
 733 
 734   // Thread priority helpers (implemented in OS-specific part)
 735   static OSReturn set_native_priority(Thread* thread, int native_prio);
 736   static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
 737   static int java_to_os_priority[CriticalPriority + 1];
 738   // Hint to the underlying OS that a task switch would not be good.
 739   // Void return because it's a hint and can fail.
 740   static void hint_no_preempt();
 741 
 742   // Used at creation if requested by the diagnostic flag PauseAtStartup.
 743   // Causes the VM to wait until an external stimulus has been applied
 744   // (for Unix, that stimulus is a signal, for Windows, an external
 745   // ResumeThread call)
 746   static void pause();
 747 
 748  protected:
 749   static long _rand_seed;                   // seed for random number generator
 750   static int _processor_count;              // number of processors
 751 
 752   static char* format_boot_path(const char* format_string,
 753                                 const char* home,
 754                                 int home_len,
 755                                 char fileSep,
 756                                 char pathSep);
 757   static bool set_boot_path(char fileSep, char pathSep);
 758   static char** split_path(const char* path, int* n);
 759 };
 760 
 761 // Note that "PAUSE" is almost always used with synchronization
 762 // so arguably we should provide Atomic::SpinPause() instead
 763 // of the global SpinPause() with C linkage.
 764 // It'd also be eligible for inlining on many platforms.
 765 
 766 extern "C" int SpinPause () ;
 767 extern "C" int SafeFetch32 (int * adr, int errValue) ;
 768 extern "C" intptr_t SafeFetchN (intptr_t * adr, intptr_t errValue) ;
 769 
 770 #endif // SHARE_VM_RUNTIME_OS_HPP
--- EOF ---