1 /* 2 * Copyright (c) 1997, 2013, 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 # include <setjmp.h> 36 #endif 37 #ifdef TARGET_OS_FAMILY_solaris 38 # include "jvm_solaris.h" 39 # include <setjmp.h> 40 #endif 41 #ifdef TARGET_OS_FAMILY_windows 42 # include "jvm_windows.h" 43 #endif 44 #ifdef TARGET_OS_FAMILY_bsd 45 # include "jvm_bsd.h" 46 # include <setjmp.h> 47 #endif 48 49 class AgentLibrary; 50 51 // os defines the interface to operating system; this includes traditional 52 // OS services (time, I/O) as well as other functionality with system- 53 // dependent code. 54 55 typedef void (*dll_func)(...); 56 57 class Thread; 58 class JavaThread; 59 class Event; 60 class DLL; 61 class FileHandle; 62 template<class E> class GrowableArray; 63 64 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose 65 66 // Platform-independent error return values from OS functions 67 enum OSReturn { 68 OS_OK = 0, // Operation was successful 69 OS_ERR = -1, // Operation failed 70 OS_INTRPT = -2, // Operation was interrupted 71 OS_TIMEOUT = -3, // Operation timed out 72 OS_NOMEM = -5, // Operation failed for lack of memory 73 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource 74 }; 75 76 enum ThreadPriority { // JLS 20.20.1-3 77 NoPriority = -1, // Initial non-priority value 78 MinPriority = 1, // Minimum priority 79 NormPriority = 5, // Normal (non-daemon) priority 80 NearMaxPriority = 9, // High priority, used for VMThread 81 MaxPriority = 10, // Highest priority, used for WatcherThread 82 // ensures that VMThread doesn't starve profiler 83 CriticalPriority = 11 // Critical thread priority 84 }; 85 86 // Executable parameter flag for os::commit_memory() and 87 // os::commit_memory_or_exit(). 88 const bool ExecMem = true; 89 90 // Typedef for structured exception handling support 91 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread); 92 93 class os: AllStatic { 94 friend class VMStructs; 95 96 public: 97 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel) 98 99 private: 100 static OSThread* _starting_thread; 101 static address _polling_page; 102 static volatile int32_t * _mem_serialize_page; 103 static uintptr_t _serialize_page_mask; 104 public: 105 static size_t _page_sizes[page_sizes_max]; 106 107 private: 108 static void init_page_sizes(size_t default_page_size) { 109 _page_sizes[0] = default_page_size; 110 _page_sizes[1] = 0; // sentinel 111 } 112 113 static char* pd_reserve_memory(size_t bytes, char* addr = 0, 114 size_t alignment_hint = 0); 115 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr); 116 static void pd_split_reserved_memory(char *base, size_t size, 117 size_t split, bool realloc); 118 static bool pd_commit_memory(char* addr, size_t bytes, bool executable); 119 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 120 bool executable); 121 // Same as pd_commit_memory() that either succeeds or calls 122 // vm_exit_out_of_memory() with the specified mesg. 123 static void pd_commit_memory_or_exit(char* addr, size_t bytes, 124 bool executable, const char* mesg); 125 static void pd_commit_memory_or_exit(char* addr, size_t size, 126 size_t alignment_hint, 127 bool executable, const char* mesg); 128 static bool pd_uncommit_memory(char* addr, size_t bytes); 129 static bool pd_release_memory(char* addr, size_t bytes); 130 131 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset, 132 char *addr, size_t bytes, bool read_only = false, 133 bool allow_exec = false); 134 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset, 135 char *addr, size_t bytes, bool read_only, 136 bool allow_exec); 137 static bool pd_unmap_memory(char *addr, size_t bytes); 138 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint); 139 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint); 140 141 142 public: 143 static void init(void); // Called before command line parsing 144 static void init_before_ergo(void); // Called after command line parsing 145 // before VM ergonomics processing. 146 static jint init_2(void); // Called after command line parsing 147 // and VM ergonomics processing 148 static void init_globals(void) { // Called from init_globals() in init.cpp 149 init_globals_ext(); 150 } 151 static void init_3(void); // Called at the end of vm init 152 153 // File names are case-insensitive on windows only 154 // Override me as needed 155 static int file_name_strcmp(const char* s1, const char* s2); 156 157 static bool getenv(const char* name, char* buffer, int len); 158 static bool have_special_privileges(); 159 160 static jlong javaTimeMillis(); 161 static jlong javaTimeNanos(); 162 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr); 163 static void run_periodic_checks(); 164 static bool supports_monotonic_clock(); 165 166 167 // Returns the elapsed time in seconds since the vm started. 168 static double elapsedTime(); 169 170 // Returns real time in seconds since an arbitrary point 171 // in the past. 172 static bool getTimesSecs(double* process_real_time, 173 double* process_user_time, 174 double* process_system_time); 175 176 // Interface to the performance counter 177 static jlong elapsed_counter(); 178 static jlong elapsed_frequency(); 179 180 // The "virtual time" of a thread is the amount of time a thread has 181 // actually run. The first function indicates whether the OS supports 182 // this functionality for the current thread, and if so: 183 // * the second enables vtime tracking (if that is required). 184 // * the third tells whether vtime is enabled. 185 // * the fourth returns the elapsed virtual time for the current 186 // thread. 187 static bool supports_vtime(); 188 static bool enable_vtime(); 189 static bool vtime_enabled(); 190 static double elapsedVTime(); 191 192 // Return current local time in a string (YYYY-MM-DD HH:MM:SS). 193 // It is MT safe, but not async-safe, as reading time zone 194 // information may require a lock on some platforms. 195 static char* local_time_string(char *buf, size_t buflen); 196 static struct tm* localtime_pd (const time_t* clock, struct tm* res); 197 // Fill in buffer with current local time as an ISO-8601 string. 198 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz. 199 // Returns buffer, or NULL if it failed. 200 static char* iso8601_time(char* buffer, size_t buffer_length); 201 202 // Interface for detecting multiprocessor system 203 static inline bool is_MP() { 204 assert(_processor_count > 0, "invalid processor count"); 205 return _processor_count > 1 || AssumeMP; 206 } 207 static julong available_memory(); 208 static julong physical_memory(); 209 static bool has_allocatable_memory_limit(julong* limit); 210 static bool is_server_class_machine(); 211 212 // number of CPUs 213 static int processor_count() { 214 return _processor_count; 215 } 216 static void set_processor_count(int count) { _processor_count = count; } 217 218 // Returns the number of CPUs this process is currently allowed to run on. 219 // Note that on some OSes this can change dynamically. 220 static int active_processor_count(); 221 222 // Bind processes to processors. 223 // This is a two step procedure: 224 // first you generate a distribution of processes to processors, 225 // then you bind processes according to that distribution. 226 // Compute a distribution for number of processes to processors. 227 // Stores the processor id's into the distribution array argument. 228 // Returns true if it worked, false if it didn't. 229 static bool distribute_processes(uint length, uint* distribution); 230 // Binds the current process to a processor. 231 // Returns true if it worked, false if it didn't. 232 static bool bind_to_processor(uint processor_id); 233 234 // Give a name to the current thread. 235 static void set_native_thread_name(const char *name); 236 237 // Interface for stack banging (predetect possible stack overflow for 238 // exception processing) There are guard pages, and above that shadow 239 // pages for stack overflow checking. 240 static bool uses_stack_guard_pages(); 241 static bool allocate_stack_guard_pages(); 242 static void bang_stack_shadow_pages(); 243 static bool stack_shadow_pages_available(Thread *thread, methodHandle method); 244 245 // OS interface to Virtual Memory 246 247 // Return the default page size. 248 static int vm_page_size(); 249 250 // Return the page size to use for a region of memory. The min_pages argument 251 // is a hint intended to limit fragmentation; it says the returned page size 252 // should be <= region_max_size / min_pages. Because min_pages is a hint, 253 // this routine may return a size larger than region_max_size / min_pages. 254 // 255 // The current implementation ignores min_pages if a larger page size is an 256 // exact multiple of both region_min_size and region_max_size. This allows 257 // larger pages to be used when doing so would not cause fragmentation; in 258 // particular, a single page can be used when region_min_size == 259 // region_max_size == a supported page size. 260 static size_t page_size_for_region(size_t region_min_size, 261 size_t region_max_size, 262 uint min_pages); 263 // Return the largest page size that can be used 264 static size_t max_page_size() { 265 // The _page_sizes array is sorted in descending order. 266 return _page_sizes[0]; 267 } 268 269 // Methods for tracing page sizes returned by the above method; enabled by 270 // TracePageSizes. The region_{min,max}_size parameters should be the values 271 // passed to page_size_for_region() and page_size should be the result of that 272 // call. The (optional) base and size parameters should come from the 273 // ReservedSpace base() and size() methods. 274 static void trace_page_sizes(const char* str, const size_t* page_sizes, 275 int count) PRODUCT_RETURN; 276 static void trace_page_sizes(const char* str, const size_t region_min_size, 277 const size_t region_max_size, 278 const size_t page_size, 279 const char* base = NULL, 280 const size_t size = 0) PRODUCT_RETURN; 281 282 static int vm_allocation_granularity(); 283 static char* reserve_memory(size_t bytes, char* addr = 0, 284 size_t alignment_hint = 0); 285 static char* reserve_memory(size_t bytes, char* addr, 286 size_t alignment_hint, MEMFLAGS flags); 287 static char* reserve_memory_aligned(size_t size, size_t alignment); 288 static char* attempt_reserve_memory_at(size_t bytes, char* addr); 289 static void split_reserved_memory(char *base, size_t size, 290 size_t split, bool realloc); 291 static bool commit_memory(char* addr, size_t bytes, bool executable); 292 static bool commit_memory(char* addr, size_t size, size_t alignment_hint, 293 bool executable); 294 // Same as commit_memory() that either succeeds or calls 295 // vm_exit_out_of_memory() with the specified mesg. 296 static void commit_memory_or_exit(char* addr, size_t bytes, 297 bool executable, const char* mesg); 298 static void commit_memory_or_exit(char* addr, size_t size, 299 size_t alignment_hint, 300 bool executable, const char* mesg); 301 static bool uncommit_memory(char* addr, size_t bytes); 302 static bool release_memory(char* addr, size_t bytes); 303 304 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX }; 305 static bool protect_memory(char* addr, size_t bytes, ProtType prot, 306 bool is_committed = true); 307 308 static bool guard_memory(char* addr, size_t bytes); 309 static bool unguard_memory(char* addr, size_t bytes); 310 static bool create_stack_guard_pages(char* addr, size_t bytes); 311 static bool pd_create_stack_guard_pages(char* addr, size_t bytes); 312 static bool remove_stack_guard_pages(char* addr, size_t bytes); 313 314 static char* map_memory(int fd, const char* file_name, size_t file_offset, 315 char *addr, size_t bytes, bool read_only = false, 316 bool allow_exec = false); 317 static char* remap_memory(int fd, const char* file_name, size_t file_offset, 318 char *addr, size_t bytes, bool read_only, 319 bool allow_exec); 320 static bool unmap_memory(char *addr, size_t bytes); 321 static void free_memory(char *addr, size_t bytes, size_t alignment_hint); 322 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint); 323 324 // NUMA-specific interface 325 static bool numa_has_static_binding(); 326 static bool numa_has_group_homing(); 327 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint); 328 static void numa_make_global(char *addr, size_t bytes); 329 static size_t numa_get_groups_num(); 330 static size_t numa_get_leaf_groups(int *ids, size_t size); 331 static bool numa_topology_changed(); 332 static int numa_get_group_id(); 333 334 // Page manipulation 335 struct page_info { 336 size_t size; 337 int lgrp_id; 338 }; 339 static bool get_page_info(char *start, page_info* info); 340 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found); 341 342 static char* non_memory_address_word(); 343 // reserve, commit and pin the entire memory region 344 static char* reserve_memory_special(size_t size, size_t alignment, 345 char* addr, bool executable); 346 static bool release_memory_special(char* addr, size_t bytes); 347 static void large_page_init(); 348 static size_t large_page_size(); 349 static bool can_commit_large_page_memory(); 350 static bool can_execute_large_page_memory(); 351 352 // OS interface to polling page 353 static address get_polling_page() { return _polling_page; } 354 static void set_polling_page(address page) { _polling_page = page; } 355 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); } 356 static void make_polling_page_unreadable(); 357 static void make_polling_page_readable(); 358 359 // Routines used to serialize the thread state without using membars 360 static void serialize_thread_states(); 361 362 // Since we write to the serialize page from every thread, we 363 // want stores to be on unique cache lines whenever possible 364 // in order to minimize CPU cross talk. We pre-compute the 365 // amount to shift the thread* to make this offset unique to 366 // each thread. 367 static int get_serialize_page_shift_count() { 368 return SerializePageShiftCount; 369 } 370 371 static void set_serialize_page_mask(uintptr_t mask) { 372 _serialize_page_mask = mask; 373 } 374 375 static unsigned int get_serialize_page_mask() { 376 return _serialize_page_mask; 377 } 378 379 static void set_memory_serialize_page(address page); 380 381 static address get_memory_serialize_page() { 382 return (address)_mem_serialize_page; 383 } 384 385 static inline void write_memory_serialize_page(JavaThread *thread) { 386 uintptr_t page_offset = ((uintptr_t)thread >> 387 get_serialize_page_shift_count()) & 388 get_serialize_page_mask(); 389 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1; 390 } 391 392 static bool is_memory_serialize_page(JavaThread *thread, address addr) { 393 if (UseMembar) return false; 394 // Previously this function calculated the exact address of this 395 // thread's serialize page, and checked if the faulting address 396 // was equal. However, some platforms mask off faulting addresses 397 // to the page size, so now we just check that the address is 398 // within the page. This makes the thread argument unnecessary, 399 // but we retain the NULL check to preserve existing behavior. 400 if (thread == NULL) return false; 401 address page = (address) _mem_serialize_page; 402 return addr >= page && addr < (page + os::vm_page_size()); 403 } 404 405 static void block_on_serialize_page_trap(); 406 407 // threads 408 409 enum ThreadType { 410 vm_thread, 411 cgc_thread, // Concurrent GC thread 412 pgc_thread, // Parallel GC thread 413 java_thread, 414 compiler_thread, 415 watcher_thread, 416 os_thread 417 }; 418 419 static bool create_thread(Thread* thread, 420 ThreadType thr_type, 421 size_t stack_size = 0); 422 static bool create_main_thread(JavaThread* thread); 423 static bool create_attached_thread(JavaThread* thread); 424 static void pd_start_thread(Thread* thread); 425 static void start_thread(Thread* thread); 426 427 static void initialize_thread(Thread* thr); 428 static void free_thread(OSThread* osthread); 429 430 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit 431 static intx current_thread_id(); 432 static int current_process_id(); 433 static int sleep(Thread* thread, jlong ms, bool interruptable); 434 // Short standalone OS sleep suitable for slow path spin loop. 435 // Ignores Thread.interrupt() (so keep it short). 436 // ms = 0, will sleep for the least amount of time allowed by the OS. 437 static void naked_short_sleep(jlong ms); 438 static void infinite_sleep(); // never returns, use with CAUTION 439 static void yield(); // Yields to all threads with same priority 440 enum YieldResult { 441 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran 442 YIELD_NONEREADY = 0, // No other runnable/ready threads. 443 // platform-specific yield return immediately 444 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY 445 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong" 446 // yield that can be used in lieu of blocking. 447 } ; 448 static YieldResult NakedYield () ; 449 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority 450 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing 451 static OSReturn set_priority(Thread* thread, ThreadPriority priority); 452 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority); 453 454 static void interrupt(Thread* thread); 455 static bool is_interrupted(Thread* thread, bool clear_interrupted); 456 457 static int pd_self_suspend_thread(Thread* thread); 458 459 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp); 460 static frame fetch_frame_from_context(void* ucVoid); 461 462 static ExtendedPC get_thread_pc(Thread *thread); 463 static void breakpoint(); 464 465 static address current_stack_pointer(); 466 static address current_stack_base(); 467 static size_t current_stack_size(); 468 469 static void verify_stack_alignment() PRODUCT_RETURN; 470 471 static int message_box(const char* title, const char* message); 472 static char* do_you_want_to_debug(const char* message); 473 474 // run cmd in a separate process and return its exit code; or -1 on failures 475 static int fork_and_exec(char *cmd); 476 477 // Set file to send error reports. 478 static void set_error_file(const char *logfile); 479 480 // os::exit() is merged with vm_exit() 481 // static void exit(int num); 482 483 // Terminate the VM, but don't exit the process 484 static void shutdown(); 485 486 // Terminate with an error. Default is to generate a core file on platforms 487 // that support such things. This calls shutdown() and then aborts. 488 static void abort(bool dump_core = true); 489 490 // Die immediately, no exit hook, no abort hook, no cleanup. 491 static void die(); 492 493 // File i/o operations 494 static const int default_file_open_flags(); 495 static int open(const char *path, int oflag, int mode); 496 static FILE* open(int fd, const char* mode); 497 static int close(int fd); 498 static jlong lseek(int fd, jlong offset, int whence); 499 static char* native_path(char *path); 500 static int ftruncate(int fd, jlong length); 501 static int fsync(int fd); 502 static int available(int fd, jlong *bytes); 503 504 //File i/o operations 505 506 static size_t read(int fd, void *buf, unsigned int nBytes); 507 static size_t restartable_read(int fd, void *buf, unsigned int nBytes); 508 static size_t write(int fd, const void *buf, unsigned int nBytes); 509 510 // Reading directories. 511 static DIR* opendir(const char* dirname); 512 static int readdir_buf_size(const char *path); 513 static struct dirent* readdir(DIR* dirp, dirent* dbuf); 514 static int closedir(DIR* dirp); 515 516 // Dynamic library extension 517 static const char* dll_file_extension(); 518 519 static const char* get_temp_directory(); 520 static const char* get_current_directory(char *buf, size_t buflen); 521 522 // Builds a platform-specific full library path given a ld path and lib name 523 // Returns true if buffer contains full path to existing file, false otherwise 524 static bool dll_build_name(char* buffer, size_t size, 525 const char* pathname, const char* fname); 526 527 // Symbol lookup, find nearest function name; basically it implements 528 // dladdr() for all platforms. Name of the nearest function is copied 529 // to buf. Distance from its base address is optionally returned as offset. 530 // If function name is not found, buf[0] is set to '\0' and offset is 531 // set to -1 (if offset is non-NULL). 532 static bool dll_address_to_function_name(address addr, char* buf, 533 int buflen, int* offset); 534 535 // Locate DLL/DSO. On success, full path of the library is copied to 536 // buf, and offset is optionally set to be the distance between addr 537 // and the library's base address. On failure, buf[0] is set to '\0' 538 // and offset is set to -1 (if offset is non-NULL). 539 static bool dll_address_to_library_name(address addr, char* buf, 540 int buflen, int* offset); 541 542 // Find out whether the pc is in the static code for jvm.dll/libjvm.so. 543 static bool address_is_in_vm(address addr); 544 545 // Loads .dll/.so and 546 // in case of error it checks if .dll/.so was built for the 547 // same architecture as HotSpot is running on 548 static void* dll_load(const char *name, char *ebuf, int ebuflen); 549 550 // lookup symbol in a shared library 551 static void* dll_lookup(void* handle, const char* name); 552 553 // Unload library 554 static void dll_unload(void *lib); 555 556 // Return the handle of this process 557 static void* get_default_process_handle(); 558 559 // Check for static linked agent library 560 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 561 size_t syms_len); 562 563 // Find agent entry point 564 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib, 565 const char *syms[], size_t syms_len); 566 567 // Print out system information; they are called by fatal error handler. 568 // Output format may be different on different platforms. 569 static void print_os_info(outputStream* st); 570 static void print_os_info_brief(outputStream* st); 571 static void print_cpu_info(outputStream* st); 572 static void pd_print_cpu_info(outputStream* st); 573 static void print_memory_info(outputStream* st); 574 static void print_dll_info(outputStream* st); 575 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len); 576 static void print_context(outputStream* st, void* context); 577 static void print_register_info(outputStream* st, void* context); 578 static void print_siginfo(outputStream* st, void* siginfo); 579 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen); 580 static void print_date_and_time(outputStream* st); 581 582 static void print_location(outputStream* st, intptr_t x, bool verbose = false); 583 static size_t lasterror(char *buf, size_t len); 584 static int get_last_error(); 585 586 // Determines whether the calling process is being debugged by a user-mode debugger. 587 static bool is_debugger_attached(); 588 589 // wait for a key press if PauseAtExit is set 590 static void wait_for_keypress_at_exit(void); 591 592 // The following two functions are used by fatal error handler to trace 593 // native (C) frames. They are not part of frame.hpp/frame.cpp because 594 // frame.hpp/cpp assume thread is JavaThread, and also because different 595 // OS/compiler may have different convention or provide different API to 596 // walk C frames. 597 // 598 // We don't attempt to become a debugger, so we only follow frames if that 599 // does not require a lookup in the unwind table, which is part of the binary 600 // file but may be unsafe to read after a fatal error. So on x86, we can 601 // only walk stack if %ebp is used as frame pointer; on ia64, it's not 602 // possible to walk C stack without having the unwind table. 603 static bool is_first_C_frame(frame *fr); 604 static frame get_sender_for_C_frame(frame *fr); 605 606 // return current frame. pc() and sp() are set to NULL on failure. 607 static frame current_frame(); 608 609 static void print_hex_dump(outputStream* st, address start, address end, int unitsize); 610 611 // returns a string to describe the exception/signal; 612 // returns NULL if exception_code is not an OS exception/signal. 613 static const char* exception_name(int exception_code, char* buf, size_t buflen); 614 615 // Returns native Java library, loads if necessary 616 static void* native_java_library(); 617 618 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler) 619 static void jvm_path(char *buf, jint buflen); 620 621 // Returns true if we are running in a headless jre. 622 static bool is_headless_jre(); 623 624 // JNI names 625 static void print_jni_name_prefix_on(outputStream* st, int args_size); 626 static void print_jni_name_suffix_on(outputStream* st, int args_size); 627 628 // File conventions 629 static const char* file_separator(); 630 static const char* line_separator(); 631 static const char* path_separator(); 632 633 // Init os specific system properties values 634 static void init_system_properties_values(); 635 636 // IO operations, non-JVM_ version. 637 static int stat(const char* path, struct stat* sbuf); 638 static bool dir_is_empty(const char* path); 639 640 // IO operations on binary files 641 static int create_binary_file(const char* path, bool rewrite_existing); 642 static jlong current_file_offset(int fd); 643 static jlong seek_to_file_offset(int fd, jlong offset); 644 645 // Thread Local Storage 646 static int allocate_thread_local_storage(); 647 static void thread_local_storage_at_put(int index, void* value); 648 static void* thread_local_storage_at(int index); 649 static void free_thread_local_storage(int index); 650 651 // Stack walk 652 static address get_caller_pc(int n = 0); 653 654 // General allocation (must be MT-safe) 655 static void* malloc (size_t size, MEMFLAGS flags, address caller_pc = 0); 656 static void* realloc (void *memblock, size_t size, MEMFLAGS flags, address caller_pc = 0); 657 static void free (void *memblock, MEMFLAGS flags = mtNone); 658 static bool check_heap(bool force = false); // verify C heap integrity 659 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup 660 661 #ifndef PRODUCT 662 static julong num_mallocs; // # of calls to malloc/realloc 663 static julong alloc_bytes; // # of bytes allocated 664 static julong num_frees; // # of calls to free 665 static julong free_bytes; // # of bytes freed 666 #endif 667 668 // SocketInterface (ex HPI SocketInterface ) 669 static int socket(int domain, int type, int protocol); 670 static int socket_close(int fd); 671 static int socket_shutdown(int fd, int howto); 672 static int recv(int fd, char* buf, size_t nBytes, uint flags); 673 static int send(int fd, char* buf, size_t nBytes, uint flags); 674 static int raw_send(int fd, char* buf, size_t nBytes, uint flags); 675 static int timeout(int fd, long timeout); 676 static int listen(int fd, int count); 677 static int connect(int fd, struct sockaddr* him, socklen_t len); 678 static int bind(int fd, struct sockaddr* him, socklen_t len); 679 static int accept(int fd, struct sockaddr* him, socklen_t* len); 680 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags, 681 struct sockaddr* from, socklen_t* fromlen); 682 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len); 683 static int sendto(int fd, char* buf, size_t len, uint flags, 684 struct sockaddr* to, socklen_t tolen); 685 static int socket_available(int fd, jint* pbytes); 686 687 static int get_sock_opt(int fd, int level, int optname, 688 char* optval, socklen_t* optlen); 689 static int set_sock_opt(int fd, int level, int optname, 690 const char* optval, socklen_t optlen); 691 static int get_host_name(char* name, int namelen); 692 693 static struct hostent* get_host_by_name(char* name); 694 695 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal) 696 static void signal_init(); 697 static void signal_init_pd(); 698 static void signal_notify(int signal_number); 699 static void* signal(int signal_number, void* handler); 700 static void signal_raise(int signal_number); 701 static int signal_wait(); 702 static int signal_lookup(); 703 static void* user_handler(); 704 static void terminate_signal_thread(); 705 static int sigexitnum_pd(); 706 707 // random number generation 708 static long random(); // return 32bit pseudorandom number 709 static void init_random(long initval); // initialize random sequence 710 711 // Structured OS Exception support 712 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread); 713 714 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits 715 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize); 716 717 // Get the default path to the core file 718 // Returns the length of the string 719 static int get_core_path(char* buffer, size_t bufferSize); 720 721 // JVMTI & JVM monitoring and management support 722 // The thread_cpu_time() and current_thread_cpu_time() are only 723 // supported if is_thread_cpu_time_supported() returns true. 724 // They are not supported on Solaris T1. 725 726 // Thread CPU Time - return the fast estimate on a platform 727 // On Solaris - call gethrvtime (fast) - user time only 728 // On Linux - fast clock_gettime where available - user+sys 729 // - otherwise: very slow /proc fs - user+sys 730 // On Windows - GetThreadTimes - user+sys 731 static jlong current_thread_cpu_time(); 732 static jlong thread_cpu_time(Thread* t); 733 734 // Thread CPU Time with user_sys_cpu_time parameter. 735 // 736 // If user_sys_cpu_time is true, user+sys time is returned. 737 // Otherwise, only user time is returned 738 static jlong current_thread_cpu_time(bool user_sys_cpu_time); 739 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time); 740 741 // Return a bunch of info about the timers. 742 // Note that the returned info for these two functions may be different 743 // on some platforms 744 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 745 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 746 747 static bool is_thread_cpu_time_supported(); 748 749 // System loadavg support. Returns -1 if load average cannot be obtained. 750 static int loadavg(double loadavg[], int nelem); 751 752 // Hook for os specific jvm options that we don't want to abort on seeing 753 static bool obsolete_option(const JavaVMOption *option); 754 755 // Extensions 756 #include "runtime/os_ext.hpp" 757 758 public: 759 class CrashProtectionCallback : public StackObj { 760 public: 761 virtual void call() = 0; 762 }; 763 764 // Platform dependent stuff 765 #ifdef TARGET_OS_FAMILY_linux 766 # include "os_linux.hpp" 767 # include "os_posix.hpp" 768 #endif 769 #ifdef TARGET_OS_FAMILY_solaris 770 # include "os_solaris.hpp" 771 # include "os_posix.hpp" 772 #endif 773 #ifdef TARGET_OS_FAMILY_windows 774 # include "os_windows.hpp" 775 #endif 776 #ifdef TARGET_OS_FAMILY_bsd 777 # include "os_posix.hpp" 778 # include "os_bsd.hpp" 779 #endif 780 #ifdef TARGET_OS_ARCH_linux_x86 781 # include "os_linux_x86.hpp" 782 #endif 783 #ifdef TARGET_OS_ARCH_linux_sparc 784 # include "os_linux_sparc.hpp" 785 #endif 786 #ifdef TARGET_OS_ARCH_linux_zero 787 # include "os_linux_zero.hpp" 788 #endif 789 #ifdef TARGET_OS_ARCH_solaris_x86 790 # include "os_solaris_x86.hpp" 791 #endif 792 #ifdef TARGET_OS_ARCH_solaris_sparc 793 # include "os_solaris_sparc.hpp" 794 #endif 795 #ifdef TARGET_OS_ARCH_windows_x86 796 # include "os_windows_x86.hpp" 797 #endif 798 #ifdef TARGET_OS_ARCH_linux_arm 799 # include "os_linux_arm.hpp" 800 #endif 801 #ifdef TARGET_OS_ARCH_linux_ppc 802 # include "os_linux_ppc.hpp" 803 #endif 804 #ifdef TARGET_OS_ARCH_bsd_x86 805 # include "os_bsd_x86.hpp" 806 #endif 807 #ifdef TARGET_OS_ARCH_bsd_zero 808 # include "os_bsd_zero.hpp" 809 #endif 810 811 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG 812 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached" 813 #endif 814 815 public: 816 #ifndef PLATFORM_PRINT_NATIVE_STACK 817 // No platform-specific code for printing the native stack. 818 static bool platform_print_native_stack(outputStream* st, void* context, 819 char *buf, int buf_size) { 820 return false; 821 } 822 #endif 823 824 // debugging support (mostly used by debug.cpp but also fatal error handler) 825 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address 826 827 static bool dont_yield(); // when true, JVM_Yield() is nop 828 static void print_statistics(); 829 830 // Thread priority helpers (implemented in OS-specific part) 831 static OSReturn set_native_priority(Thread* thread, int native_prio); 832 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr); 833 static int java_to_os_priority[CriticalPriority + 1]; 834 // Hint to the underlying OS that a task switch would not be good. 835 // Void return because it's a hint and can fail. 836 static void hint_no_preempt(); 837 static const char* native_thread_creation_failed_msg() { 838 return OS_NATIVE_THREAD_CREATION_FAILED_MSG; 839 } 840 841 // Used at creation if requested by the diagnostic flag PauseAtStartup. 842 // Causes the VM to wait until an external stimulus has been applied 843 // (for Unix, that stimulus is a signal, for Windows, an external 844 // ResumeThread call) 845 static void pause(); 846 847 // Builds a platform dependent Agent_OnLoad_<libname> function name 848 // which is used to find statically linked in agents. 849 static char* build_agent_function_name(const char *sym, const char *cname, 850 bool is_absolute_path); 851 852 class SuspendedThreadTaskContext { 853 public: 854 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {} 855 Thread* thread() const { return _thread; } 856 void* ucontext() const { return _ucontext; } 857 private: 858 Thread* _thread; 859 void* _ucontext; 860 }; 861 862 class SuspendedThreadTask { 863 public: 864 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {} 865 virtual ~SuspendedThreadTask() {} 866 void run(); 867 bool is_done() { return _done; } 868 virtual void do_task(const SuspendedThreadTaskContext& context) = 0; 869 protected: 870 private: 871 void internal_do_task(); 872 Thread* _thread; 873 bool _done; 874 }; 875 876 #ifndef TARGET_OS_FAMILY_windows 877 // Suspend/resume support 878 // Protocol: 879 // 880 // a thread starts in SR_RUNNING 881 // 882 // SR_RUNNING can go to 883 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it 884 // SR_SUSPEND_REQUEST can go to 885 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout) 886 // * SR_SUSPENDED if the stopped thread receives the signal and switches state 887 // SR_SUSPENDED can go to 888 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume 889 // SR_WAKEUP_REQUEST can go to 890 // * SR_RUNNING when the stopped thread receives the signal 891 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again) 892 class SuspendResume { 893 public: 894 enum State { 895 SR_RUNNING, 896 SR_SUSPEND_REQUEST, 897 SR_SUSPENDED, 898 SR_WAKEUP_REQUEST 899 }; 900 901 private: 902 volatile State _state; 903 904 private: 905 /* try to switch state from state "from" to state "to" 906 * returns the state set after the method is complete 907 */ 908 State switch_state(State from, State to); 909 910 public: 911 SuspendResume() : _state(SR_RUNNING) { } 912 913 State state() const { return _state; } 914 915 State request_suspend() { 916 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST); 917 } 918 919 State cancel_suspend() { 920 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING); 921 } 922 923 State suspended() { 924 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED); 925 } 926 927 State request_wakeup() { 928 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST); 929 } 930 931 State running() { 932 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING); 933 } 934 935 bool is_running() const { 936 return _state == SR_RUNNING; 937 } 938 939 bool is_suspend_request() const { 940 return _state == SR_SUSPEND_REQUEST; 941 } 942 943 bool is_suspended() const { 944 return _state == SR_SUSPENDED; 945 } 946 }; 947 #endif 948 949 950 protected: 951 static long _rand_seed; // seed for random number generator 952 static int _processor_count; // number of processors 953 954 static char* format_boot_path(const char* format_string, 955 const char* home, 956 int home_len, 957 char fileSep, 958 char pathSep); 959 static bool set_boot_path(char fileSep, char pathSep); 960 static char** split_path(const char* path, int* n); 961 962 }; 963 964 // Note that "PAUSE" is almost always used with synchronization 965 // so arguably we should provide Atomic::SpinPause() instead 966 // of the global SpinPause() with C linkage. 967 // It'd also be eligible for inlining on many platforms. 968 969 extern "C" int SpinPause(); 970 971 #endif // SHARE_VM_RUNTIME_OS_HPP