1 /* 2 * Copyright (c) 1997, 2017, 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 "jvm.h" 29 #include "jvmtifiles/jvmti.h" 30 #include "runtime/extendedPC.hpp" 31 #include "runtime/handles.hpp" 32 #include "utilities/macros.hpp" 33 #ifndef _WINDOWS 34 # include <setjmp.h> 35 #endif 36 #ifdef __APPLE__ 37 # include <mach/mach_time.h> 38 #endif 39 40 class AgentLibrary; 41 class frame; 42 43 // os defines the interface to operating system; this includes traditional 44 // OS services (time, I/O) as well as other functionality with system- 45 // dependent code. 46 47 typedef void (*dll_func)(...); 48 49 class Thread; 50 class JavaThread; 51 class Event; 52 class DLL; 53 class FileHandle; 54 class NativeCallStack; 55 56 template<class E> class GrowableArray; 57 58 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose 59 60 // Platform-independent error return values from OS functions 61 enum OSReturn { 62 OS_OK = 0, // Operation was successful 63 OS_ERR = -1, // Operation failed 64 OS_INTRPT = -2, // Operation was interrupted 65 OS_TIMEOUT = -3, // Operation timed out 66 OS_NOMEM = -5, // Operation failed for lack of memory 67 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource 68 }; 69 70 enum ThreadPriority { // JLS 20.20.1-3 71 NoPriority = -1, // Initial non-priority value 72 MinPriority = 1, // Minimum priority 73 NormPriority = 5, // Normal (non-daemon) priority 74 NearMaxPriority = 9, // High priority, used for VMThread 75 MaxPriority = 10, // Highest priority, used for WatcherThread 76 // ensures that VMThread doesn't starve profiler 77 CriticalPriority = 11 // Critical thread priority 78 }; 79 80 // Executable parameter flag for os::commit_memory() and 81 // os::commit_memory_or_exit(). 82 const bool ExecMem = true; 83 84 // Typedef for structured exception handling support 85 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread); 86 87 class MallocTracker; 88 89 class os: AllStatic { 90 friend class VMStructs; 91 friend class JVMCIVMStructs; 92 friend class MallocTracker; 93 public: 94 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel) 95 96 private: 97 static OSThread* _starting_thread; 98 static address _polling_page; 99 static volatile int32_t * _mem_serialize_page; 100 static uintptr_t _serialize_page_mask; 101 public: 102 static size_t _page_sizes[page_sizes_max]; 103 104 private: 105 static void init_page_sizes(size_t default_page_size) { 106 _page_sizes[0] = default_page_size; 107 _page_sizes[1] = 0; // sentinel 108 } 109 110 static char* pd_reserve_memory(size_t bytes, char* addr = 0, 111 size_t alignment_hint = 0); 112 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr); 113 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc); 114 static void pd_split_reserved_memory(char *base, size_t size, 115 size_t split, bool realloc); 116 static bool pd_commit_memory(char* addr, size_t bytes, bool executable); 117 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 118 bool executable); 119 // Same as pd_commit_memory() that either succeeds or calls 120 // vm_exit_out_of_memory() with the specified mesg. 121 static void pd_commit_memory_or_exit(char* addr, size_t bytes, 122 bool executable, const char* mesg); 123 static void pd_commit_memory_or_exit(char* addr, size_t size, 124 size_t alignment_hint, 125 bool executable, const char* mesg); 126 static bool pd_uncommit_memory(char* addr, size_t bytes); 127 static bool pd_release_memory(char* addr, size_t bytes); 128 129 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset, 130 char *addr, size_t bytes, bool read_only = false, 131 bool allow_exec = false); 132 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset, 133 char *addr, size_t bytes, bool read_only, 134 bool allow_exec); 135 static bool pd_unmap_memory(char *addr, size_t bytes); 136 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint); 137 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint); 138 139 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned); 140 141 // Get summary strings for system information in buffer provided 142 static void get_summary_cpu_info(char* buf, size_t buflen); 143 static void get_summary_os_info(char* buf, size_t buflen); 144 145 static void initialize_initial_active_processor_count(); 146 public: 147 static void init(void); // Called before command line parsing 148 static void init_before_ergo(void); // Called after command line parsing 149 // before VM ergonomics processing. 150 static jint init_2(void); // Called after command line parsing 151 // and VM ergonomics processing 152 static void init_globals(void) { // Called from init_globals() in init.cpp 153 init_globals_ext(); 154 } 155 156 // File names are case-insensitive on windows only 157 // Override me as needed 158 static int file_name_strcmp(const char* s1, const char* s2); 159 160 // unset environment variable 161 static bool unsetenv(const char* name); 162 163 static bool have_special_privileges(); 164 165 static jlong javaTimeMillis(); 166 static jlong javaTimeNanos(); 167 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr); 168 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos); 169 static void run_periodic_checks(); 170 static bool supports_monotonic_clock(); 171 172 // Returns the elapsed time in seconds since the vm started. 173 static double elapsedTime(); 174 175 // Returns real time in seconds since an arbitrary point 176 // in the past. 177 static bool getTimesSecs(double* process_real_time, 178 double* process_user_time, 179 double* process_system_time); 180 181 // Interface to the performance counter 182 static jlong elapsed_counter(); 183 static jlong elapsed_frequency(); 184 185 // The "virtual time" of a thread is the amount of time a thread has 186 // actually run. The first function indicates whether the OS supports 187 // this functionality for the current thread, and if so: 188 // * the second enables vtime tracking (if that is required). 189 // * the third tells whether vtime is enabled. 190 // * the fourth returns the elapsed virtual time for the current 191 // thread. 192 static bool supports_vtime(); 193 static bool enable_vtime(); 194 static bool vtime_enabled(); 195 static double elapsedVTime(); 196 197 // Return current local time in a string (YYYY-MM-DD HH:MM:SS). 198 // It is MT safe, but not async-safe, as reading time zone 199 // information may require a lock on some platforms. 200 static char* local_time_string(char *buf, size_t buflen); 201 static struct tm* localtime_pd (const time_t* clock, struct tm* res); 202 static struct tm* gmtime_pd (const time_t* clock, struct tm* res); 203 // Fill in buffer with current local time as an ISO-8601 string. 204 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz. 205 // Returns buffer, or NULL if it failed. 206 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false); 207 208 // Interface for detecting multiprocessor system 209 static inline bool is_MP() { 210 // During bootstrap if _processor_count is not yet initialized 211 // we claim to be MP as that is safest. If any platform has a 212 // stub generator that might be triggered in this phase and for 213 // which being declared MP when in fact not, is a problem - then 214 // the bootstrap routine for the stub generator needs to check 215 // the processor count directly and leave the bootstrap routine 216 // in place until called after initialization has ocurred. 217 return AssumeMP || (_processor_count != 1); 218 } 219 static julong available_memory(); 220 static julong physical_memory(); 221 static bool has_allocatable_memory_limit(julong* limit); 222 static bool is_server_class_machine(); 223 224 // number of CPUs 225 static int processor_count() { 226 return _processor_count; 227 } 228 static void set_processor_count(int count) { _processor_count = count; } 229 230 // Returns the number of CPUs this process is currently allowed to run on. 231 // Note that on some OSes this can change dynamically. 232 static int active_processor_count(); 233 234 // At startup the number of active CPUs this process is allowed to run on. 235 // This value does not change dynamically. May be different from active_processor_count(). 236 static int initial_active_processor_count() { 237 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet."); 238 return _initial_active_processor_count; 239 } 240 241 // Bind processes to processors. 242 // This is a two step procedure: 243 // first you generate a distribution of processes to processors, 244 // then you bind processes according to that distribution. 245 // Compute a distribution for number of processes to processors. 246 // Stores the processor id's into the distribution array argument. 247 // Returns true if it worked, false if it didn't. 248 static bool distribute_processes(uint length, uint* distribution); 249 // Binds the current process to a processor. 250 // Returns true if it worked, false if it didn't. 251 static bool bind_to_processor(uint processor_id); 252 253 // Give a name to the current thread. 254 static void set_native_thread_name(const char *name); 255 256 // Interface for stack banging (predetect possible stack overflow for 257 // exception processing) There are guard pages, and above that shadow 258 // pages for stack overflow checking. 259 static bool uses_stack_guard_pages(); 260 static bool must_commit_stack_guard_pages(); 261 static void map_stack_shadow_pages(address sp); 262 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp); 263 264 // OS interface to Virtual Memory 265 266 // Return the default page size. 267 static int vm_page_size(); 268 269 // Returns the page size to use for a region of memory. 270 // region_size / min_pages will always be greater than or equal to the 271 // returned value. The returned value will divide region_size. 272 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages); 273 274 // Returns the page size to use for a region of memory. 275 // region_size / min_pages will always be greater than or equal to the 276 // returned value. The returned value might not divide region_size. 277 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages); 278 279 // Return the largest page size that can be used 280 static size_t max_page_size() { 281 // The _page_sizes array is sorted in descending order. 282 return _page_sizes[0]; 283 } 284 285 // Methods for tracing page sizes returned by the above method. 286 // The region_{min,max}_size parameters should be the values 287 // passed to page_size_for_region() and page_size should be the result of that 288 // call. The (optional) base and size parameters should come from the 289 // ReservedSpace base() and size() methods. 290 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count); 291 static void trace_page_sizes(const char* str, 292 const size_t region_min_size, 293 const size_t region_max_size, 294 const size_t page_size, 295 const char* base, 296 const size_t size); 297 static void trace_page_sizes_for_requested_size(const char* str, 298 const size_t requested_size, 299 const size_t page_size, 300 const size_t alignment, 301 const char* base, 302 const size_t size); 303 304 static int vm_allocation_granularity(); 305 static char* reserve_memory(size_t bytes, char* addr = 0, 306 size_t alignment_hint = 0, int file_desc = -1); 307 static char* reserve_memory(size_t bytes, char* addr, 308 size_t alignment_hint, MEMFLAGS flags); 309 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1); 310 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1); 311 static void split_reserved_memory(char *base, size_t size, 312 size_t split, bool realloc); 313 static bool commit_memory(char* addr, size_t bytes, bool executable); 314 static bool commit_memory(char* addr, size_t size, size_t alignment_hint, 315 bool executable); 316 // Same as commit_memory() that either succeeds or calls 317 // vm_exit_out_of_memory() with the specified mesg. 318 static void commit_memory_or_exit(char* addr, size_t bytes, 319 bool executable, const char* mesg); 320 static void commit_memory_or_exit(char* addr, size_t size, 321 size_t alignment_hint, 322 bool executable, const char* mesg); 323 static bool uncommit_memory(char* addr, size_t bytes); 324 static bool release_memory(char* addr, size_t bytes); 325 326 // Touch memory pages that cover the memory range from start to end (exclusive) 327 // to make the OS back the memory range with actual memory. 328 // Current implementation may not touch the last page if unaligned addresses 329 // are passed. 330 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size()); 331 332 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX }; 333 static bool protect_memory(char* addr, size_t bytes, ProtType prot, 334 bool is_committed = true); 335 336 static bool guard_memory(char* addr, size_t bytes); 337 static bool unguard_memory(char* addr, size_t bytes); 338 static bool create_stack_guard_pages(char* addr, size_t bytes); 339 static bool pd_create_stack_guard_pages(char* addr, size_t bytes); 340 static bool remove_stack_guard_pages(char* addr, size_t bytes); 341 // Helper function to create a new file with template jvmheap.XXXXXX. 342 // Returns a valid fd on success or else returns -1 343 static int create_file_for_heap(const char* dir); 344 // Map memory to the file referred by fd. This function is slightly different from map_memory() 345 // and is added to be used for implementation of -XX:AllocateHeapAt 346 static char* map_memory_to_file(char* base, size_t size, int fd); 347 // Replace existing reserved memory with file mapping 348 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd); 349 350 static char* map_memory(int fd, const char* file_name, size_t file_offset, 351 char *addr, size_t bytes, bool read_only = false, 352 bool allow_exec = false); 353 static char* remap_memory(int fd, const char* file_name, size_t file_offset, 354 char *addr, size_t bytes, bool read_only, 355 bool allow_exec); 356 static bool unmap_memory(char *addr, size_t bytes); 357 static void free_memory(char *addr, size_t bytes, size_t alignment_hint); 358 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint); 359 360 // NUMA-specific interface 361 static bool numa_has_static_binding(); 362 static bool numa_has_group_homing(); 363 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint); 364 static void numa_make_global(char *addr, size_t bytes); 365 static size_t numa_get_groups_num(); 366 static size_t numa_get_leaf_groups(int *ids, size_t size); 367 static bool numa_topology_changed(); 368 static int numa_get_group_id(); 369 370 // Page manipulation 371 struct page_info { 372 size_t size; 373 int lgrp_id; 374 }; 375 static bool get_page_info(char *start, page_info* info); 376 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found); 377 378 static char* non_memory_address_word(); 379 // reserve, commit and pin the entire memory region 380 static char* reserve_memory_special(size_t size, size_t alignment, 381 char* addr, bool executable); 382 static bool release_memory_special(char* addr, size_t bytes); 383 static void large_page_init(); 384 static size_t large_page_size(); 385 static bool can_commit_large_page_memory(); 386 static bool can_execute_large_page_memory(); 387 388 // OS interface to polling page 389 static address get_polling_page() { return _polling_page; } 390 static void set_polling_page(address page) { _polling_page = page; } 391 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); } 392 static void make_polling_page_unreadable(); 393 static void make_polling_page_readable(); 394 395 // Routines used to serialize the thread state without using membars 396 static void serialize_thread_states(); 397 398 // Since we write to the serialize page from every thread, we 399 // want stores to be on unique cache lines whenever possible 400 // in order to minimize CPU cross talk. We pre-compute the 401 // amount to shift the thread* to make this offset unique to 402 // each thread. 403 static int get_serialize_page_shift_count() { 404 return SerializePageShiftCount; 405 } 406 407 static void set_serialize_page_mask(uintptr_t mask) { 408 _serialize_page_mask = mask; 409 } 410 411 static unsigned int get_serialize_page_mask() { 412 return _serialize_page_mask; 413 } 414 415 static void set_memory_serialize_page(address page); 416 417 static address get_memory_serialize_page() { 418 return (address)_mem_serialize_page; 419 } 420 421 static inline void write_memory_serialize_page(JavaThread *thread) { 422 uintptr_t page_offset = ((uintptr_t)thread >> 423 get_serialize_page_shift_count()) & 424 get_serialize_page_mask(); 425 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1; 426 } 427 428 static bool is_memory_serialize_page(JavaThread *thread, address addr) { 429 if (UseMembar) return false; 430 // Previously this function calculated the exact address of this 431 // thread's serialize page, and checked if the faulting address 432 // was equal. However, some platforms mask off faulting addresses 433 // to the page size, so now we just check that the address is 434 // within the page. This makes the thread argument unnecessary, 435 // but we retain the NULL check to preserve existing behavior. 436 if (thread == NULL) return false; 437 address page = (address) _mem_serialize_page; 438 return addr >= page && addr < (page + os::vm_page_size()); 439 } 440 441 static void block_on_serialize_page_trap(); 442 443 // threads 444 445 enum ThreadType { 446 vm_thread, 447 cgc_thread, // Concurrent GC thread 448 pgc_thread, // Parallel GC thread 449 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads. 450 compiler_thread, 451 watcher_thread, 452 os_thread 453 }; 454 455 static bool create_thread(Thread* thread, 456 ThreadType thr_type, 457 size_t req_stack_size = 0); 458 static bool create_main_thread(JavaThread* thread); 459 static bool create_attached_thread(JavaThread* thread); 460 static void pd_start_thread(Thread* thread); 461 static void start_thread(Thread* thread); 462 463 static void initialize_thread(Thread* thr); 464 static void free_thread(OSThread* osthread); 465 466 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit 467 static intx current_thread_id(); 468 static int current_process_id(); 469 static int sleep(Thread* thread, jlong ms, bool interruptable); 470 // Short standalone OS sleep suitable for slow path spin loop. 471 // Ignores Thread.interrupt() (so keep it short). 472 // ms = 0, will sleep for the least amount of time allowed by the OS. 473 static void naked_short_sleep(jlong ms); 474 static void infinite_sleep(); // never returns, use with CAUTION 475 static void naked_yield () ; 476 static OSReturn set_priority(Thread* thread, ThreadPriority priority); 477 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority); 478 479 static void interrupt(Thread* thread); 480 static bool is_interrupted(Thread* thread, bool clear_interrupted); 481 482 static int pd_self_suspend_thread(Thread* thread); 483 484 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp); 485 static frame fetch_frame_from_context(const void* ucVoid); 486 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid); 487 488 static void breakpoint(); 489 static bool start_debugging(char *buf, int buflen); 490 491 static address current_stack_pointer(); 492 static address current_stack_base(); 493 static size_t current_stack_size(); 494 495 static void verify_stack_alignment() PRODUCT_RETURN; 496 497 static bool message_box(const char* title, const char* message); 498 static char* do_you_want_to_debug(const char* message); 499 500 // run cmd in a separate process and return its exit code; or -1 on failures 501 static int fork_and_exec(char *cmd); 502 503 // Call ::exit() on all platforms but Windows 504 static void exit(int num); 505 506 // Terminate the VM, but don't exit the process 507 static void shutdown(); 508 509 // Terminate with an error. Default is to generate a core file on platforms 510 // that support such things. This calls shutdown() and then aborts. 511 static void abort(bool dump_core, void *siginfo, const void *context); 512 static void abort(bool dump_core = true); 513 514 // Die immediately, no exit hook, no abort hook, no cleanup. 515 static void die(); 516 517 // File i/o operations 518 static const int default_file_open_flags(); 519 static int open(const char *path, int oflag, int mode); 520 static FILE* open(int fd, const char* mode); 521 static int close(int fd); 522 static jlong lseek(int fd, jlong offset, int whence); 523 static char* native_path(char *path); 524 static int ftruncate(int fd, jlong length); 525 static int fsync(int fd); 526 static int available(int fd, jlong *bytes); 527 static int get_fileno(FILE* fp); 528 static void flockfile(FILE* fp); 529 static void funlockfile(FILE* fp); 530 531 static int compare_file_modified_times(const char* file1, const char* file2); 532 533 //File i/o operations 534 535 static size_t read(int fd, void *buf, unsigned int nBytes); 536 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset); 537 static size_t restartable_read(int fd, void *buf, unsigned int nBytes); 538 static size_t write(int fd, const void *buf, unsigned int nBytes); 539 540 // Reading directories. 541 static DIR* opendir(const char* dirname); 542 static int readdir_buf_size(const char *path); 543 static struct dirent* readdir(DIR* dirp, dirent* dbuf); 544 static int closedir(DIR* dirp); 545 546 // Dynamic library extension 547 static const char* dll_file_extension(); 548 549 static const char* get_temp_directory(); 550 static const char* get_current_directory(char *buf, size_t buflen); 551 552 // Builds the platform-specific name of a library. 553 // Returns false if the buffer is too small. 554 static bool dll_build_name(char* buffer, size_t size, 555 const char* fname); 556 557 // Builds a platform-specific full library path given an ld path and 558 // unadorned library name. Returns true if the buffer contains a full 559 // path to an existing file, false otherwise. If pathname is empty, 560 // uses the path to the current directory. 561 static bool dll_locate_lib(char* buffer, size_t size, 562 const char* pathname, const char* fname); 563 564 // Symbol lookup, find nearest function name; basically it implements 565 // dladdr() for all platforms. Name of the nearest function is copied 566 // to buf. Distance from its base address is optionally returned as offset. 567 // If function name is not found, buf[0] is set to '\0' and offset is 568 // set to -1 (if offset is non-NULL). 569 static bool dll_address_to_function_name(address addr, char* buf, 570 int buflen, int* offset, 571 bool demangle = true); 572 573 // Locate DLL/DSO. On success, full path of the library is copied to 574 // buf, and offset is optionally set to be the distance between addr 575 // and the library's base address. On failure, buf[0] is set to '\0' 576 // and offset is set to -1 (if offset is non-NULL). 577 static bool dll_address_to_library_name(address addr, char* buf, 578 int buflen, int* offset); 579 580 // Find out whether the pc is in the static code for jvm.dll/libjvm.so. 581 static bool address_is_in_vm(address addr); 582 583 // Loads .dll/.so and 584 // in case of error it checks if .dll/.so was built for the 585 // same architecture as HotSpot is running on 586 static void* dll_load(const char *name, char *ebuf, int ebuflen); 587 588 // lookup symbol in a shared library 589 static void* dll_lookup(void* handle, const char* name); 590 591 // Unload library 592 static void dll_unload(void *lib); 593 594 // Callback for loaded module information 595 // Input parameters: 596 // char* module_file_name, 597 // address module_base_addr, 598 // address module_top_addr, 599 // void* param 600 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *); 601 602 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param); 603 604 // Return the handle of this process 605 static void* get_default_process_handle(); 606 607 // Check for static linked agent library 608 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 609 size_t syms_len); 610 611 // Find agent entry point 612 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib, 613 const char *syms[], size_t syms_len); 614 615 // Write to stream 616 static int log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0); 617 618 // Get host name in buffer provided 619 static bool get_host_name(char* buf, size_t buflen); 620 621 // Print out system information; they are called by fatal error handler. 622 // Output format may be different on different platforms. 623 static void print_os_info(outputStream* st); 624 static void print_os_info_brief(outputStream* st); 625 static void print_cpu_info(outputStream* st, char* buf, size_t buflen); 626 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen); 627 static void print_summary_info(outputStream* st, char* buf, size_t buflen); 628 static void print_memory_info(outputStream* st); 629 static void print_dll_info(outputStream* st); 630 static void print_environment_variables(outputStream* st, const char** env_list); 631 static void print_context(outputStream* st, const void* context); 632 static void print_register_info(outputStream* st, const void* context); 633 static void print_siginfo(outputStream* st, const void* siginfo); 634 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen); 635 static void print_date_and_time(outputStream* st, char* buf, size_t buflen); 636 637 static void print_location(outputStream* st, intptr_t x, bool verbose = false); 638 static size_t lasterror(char *buf, size_t len); 639 static int get_last_error(); 640 641 // Replacement for strerror(). 642 // Will return the english description of the error (e.g. "File not found", as 643 // suggested in the POSIX standard. 644 // Will return "Unknown error" for an unknown errno value. 645 // Will not attempt to localize the returned string. 646 // Will always return a valid string which is a static constant. 647 // Will not change the value of errno. 648 static const char* strerror(int e); 649 650 // Will return the literalized version of the given errno (e.g. "EINVAL" 651 // for EINVAL). 652 // Will return "Unknown error" for an unknown errno value. 653 // Will always return a valid string which is a static constant. 654 // Will not change the value of errno. 655 static const char* errno_name(int e); 656 657 // Determines whether the calling process is being debugged by a user-mode debugger. 658 static bool is_debugger_attached(); 659 660 // wait for a key press if PauseAtExit is set 661 static void wait_for_keypress_at_exit(void); 662 663 // The following two functions are used by fatal error handler to trace 664 // native (C) frames. They are not part of frame.hpp/frame.cpp because 665 // frame.hpp/cpp assume thread is JavaThread, and also because different 666 // OS/compiler may have different convention or provide different API to 667 // walk C frames. 668 // 669 // We don't attempt to become a debugger, so we only follow frames if that 670 // does not require a lookup in the unwind table, which is part of the binary 671 // file but may be unsafe to read after a fatal error. So on x86, we can 672 // only walk stack if %ebp is used as frame pointer; on ia64, it's not 673 // possible to walk C stack without having the unwind table. 674 static bool is_first_C_frame(frame *fr); 675 static frame get_sender_for_C_frame(frame *fr); 676 677 // return current frame. pc() and sp() are set to NULL on failure. 678 static frame current_frame(); 679 680 static void print_hex_dump(outputStream* st, address start, address end, int unitsize); 681 682 // returns a string to describe the exception/signal; 683 // returns NULL if exception_code is not an OS exception/signal. 684 static const char* exception_name(int exception_code, char* buf, size_t buflen); 685 686 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV). 687 static int get_signal_number(const char* signal_name); 688 689 // Returns native Java library, loads if necessary 690 static void* native_java_library(); 691 692 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler) 693 static void jvm_path(char *buf, jint buflen); 694 695 // Returns true if we are running in a headless jre. 696 static bool is_headless_jre(); 697 698 // JNI names 699 static void print_jni_name_prefix_on(outputStream* st, int args_size); 700 static void print_jni_name_suffix_on(outputStream* st, int args_size); 701 702 // Init os specific system properties values 703 static void init_system_properties_values(); 704 705 // IO operations, non-JVM_ version. 706 static int stat(const char* path, struct stat* sbuf); 707 static bool dir_is_empty(const char* path); 708 709 // IO operations on binary files 710 static int create_binary_file(const char* path, bool rewrite_existing); 711 static jlong current_file_offset(int fd); 712 static jlong seek_to_file_offset(int fd, jlong offset); 713 714 // Retrieve native stack frames. 715 // Parameter: 716 // stack: an array to storage stack pointers. 717 // frames: size of above array. 718 // toSkip: number of stack frames to skip at the beginning. 719 // Return: number of stack frames captured. 720 static int get_native_stack(address* stack, int size, int toSkip = 0); 721 722 // General allocation (must be MT-safe) 723 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack); 724 static void* malloc (size_t size, MEMFLAGS flags); 725 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack); 726 static void* realloc (void *memblock, size_t size, MEMFLAGS flag); 727 728 static void free (void *memblock); 729 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup 730 // Like strdup, but exit VM when strdup() returns NULL 731 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal); 732 733 #ifndef PRODUCT 734 static julong num_mallocs; // # of calls to malloc/realloc 735 static julong alloc_bytes; // # of bytes allocated 736 static julong num_frees; // # of calls to free 737 static julong free_bytes; // # of bytes freed 738 #endif 739 740 // SocketInterface (ex HPI SocketInterface ) 741 static int socket(int domain, int type, int protocol); 742 static int socket_close(int fd); 743 static int recv(int fd, char* buf, size_t nBytes, uint flags); 744 static int send(int fd, char* buf, size_t nBytes, uint flags); 745 static int raw_send(int fd, char* buf, size_t nBytes, uint flags); 746 static int connect(int fd, struct sockaddr* him, socklen_t len); 747 static struct hostent* get_host_by_name(char* name); 748 749 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal) 750 static void signal_init(TRAPS); 751 static void signal_init_pd(); 752 static void signal_notify(int signal_number); 753 static void* signal(int signal_number, void* handler); 754 static void signal_raise(int signal_number); 755 static int signal_wait(); 756 static int signal_lookup(); 757 static void* user_handler(); 758 static void terminate_signal_thread(); 759 static int sigexitnum_pd(); 760 761 // random number generation 762 static int random(); // return 32bit pseudorandom number 763 static void init_random(unsigned int initval); // initialize random sequence 764 765 // Structured OS Exception support 766 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread); 767 768 // On Posix compatible OS it will simply check core dump limits while on Windows 769 // it will check if dump file can be created. Check or prepare a core dump to be 770 // taken at a later point in the same thread in os::abort(). Use the caller 771 // provided buffer as a scratch buffer. The status message which will be written 772 // into the error log either is file location or a short error message, depending 773 // on the checking result. 774 static void check_dump_limit(char* buffer, size_t bufferSize); 775 776 // Get the default path to the core file 777 // Returns the length of the string 778 static int get_core_path(char* buffer, size_t bufferSize); 779 780 // JVMTI & JVM monitoring and management support 781 // The thread_cpu_time() and current_thread_cpu_time() are only 782 // supported if is_thread_cpu_time_supported() returns true. 783 // They are not supported on Solaris T1. 784 785 // Thread CPU Time - return the fast estimate on a platform 786 // On Solaris - call gethrvtime (fast) - user time only 787 // On Linux - fast clock_gettime where available - user+sys 788 // - otherwise: very slow /proc fs - user+sys 789 // On Windows - GetThreadTimes - user+sys 790 static jlong current_thread_cpu_time(); 791 static jlong thread_cpu_time(Thread* t); 792 793 // Thread CPU Time with user_sys_cpu_time parameter. 794 // 795 // If user_sys_cpu_time is true, user+sys time is returned. 796 // Otherwise, only user time is returned 797 static jlong current_thread_cpu_time(bool user_sys_cpu_time); 798 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time); 799 800 // Return a bunch of info about the timers. 801 // Note that the returned info for these two functions may be different 802 // on some platforms 803 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 804 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 805 806 static bool is_thread_cpu_time_supported(); 807 808 // System loadavg support. Returns -1 if load average cannot be obtained. 809 static int loadavg(double loadavg[], int nelem); 810 811 // Hook for os specific jvm options that we don't want to abort on seeing 812 static bool obsolete_option(const JavaVMOption *option); 813 814 // Amount beyond the callee frame size that we bang the stack. 815 static int extra_bang_size_in_bytes(); 816 817 static char** split_path(const char* path, int* n); 818 819 // Extensions 820 #include "runtime/os_ext.hpp" 821 822 public: 823 class CrashProtectionCallback : public StackObj { 824 public: 825 virtual void call() = 0; 826 }; 827 828 // Platform dependent stuff 829 #ifndef _WINDOWS 830 # include "os_posix.hpp" 831 #endif 832 #include OS_CPU_HEADER(os) 833 #include OS_HEADER(os) 834 835 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG 836 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached" 837 #endif 838 839 public: 840 #ifndef PLATFORM_PRINT_NATIVE_STACK 841 // No platform-specific code for printing the native stack. 842 static bool platform_print_native_stack(outputStream* st, const void* context, 843 char *buf, int buf_size) { 844 return false; 845 } 846 #endif 847 848 // debugging support (mostly used by debug.cpp but also fatal error handler) 849 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address 850 851 static bool dont_yield(); // when true, JVM_Yield() is nop 852 static void print_statistics(); 853 854 // Thread priority helpers (implemented in OS-specific part) 855 static OSReturn set_native_priority(Thread* thread, int native_prio); 856 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr); 857 static int java_to_os_priority[CriticalPriority + 1]; 858 // Hint to the underlying OS that a task switch would not be good. 859 // Void return because it's a hint and can fail. 860 static void hint_no_preempt(); 861 static const char* native_thread_creation_failed_msg() { 862 return OS_NATIVE_THREAD_CREATION_FAILED_MSG; 863 } 864 865 // Used at creation if requested by the diagnostic flag PauseAtStartup. 866 // Causes the VM to wait until an external stimulus has been applied 867 // (for Unix, that stimulus is a signal, for Windows, an external 868 // ResumeThread call) 869 static void pause(); 870 871 // Builds a platform dependent Agent_OnLoad_<libname> function name 872 // which is used to find statically linked in agents. 873 static char* build_agent_function_name(const char *sym, const char *cname, 874 bool is_absolute_path); 875 876 class SuspendedThreadTaskContext { 877 public: 878 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {} 879 Thread* thread() const { return _thread; } 880 void* ucontext() const { return _ucontext; } 881 private: 882 Thread* _thread; 883 void* _ucontext; 884 }; 885 886 class SuspendedThreadTask { 887 public: 888 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {} 889 virtual ~SuspendedThreadTask() {} 890 void run(); 891 bool is_done() { return _done; } 892 virtual void do_task(const SuspendedThreadTaskContext& context) = 0; 893 protected: 894 private: 895 void internal_do_task(); 896 Thread* _thread; 897 bool _done; 898 }; 899 900 #ifndef _WINDOWS 901 // Suspend/resume support 902 // Protocol: 903 // 904 // a thread starts in SR_RUNNING 905 // 906 // SR_RUNNING can go to 907 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it 908 // SR_SUSPEND_REQUEST can go to 909 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout) 910 // * SR_SUSPENDED if the stopped thread receives the signal and switches state 911 // SR_SUSPENDED can go to 912 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume 913 // SR_WAKEUP_REQUEST can go to 914 // * SR_RUNNING when the stopped thread receives the signal 915 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again) 916 class SuspendResume { 917 public: 918 enum State { 919 SR_RUNNING, 920 SR_SUSPEND_REQUEST, 921 SR_SUSPENDED, 922 SR_WAKEUP_REQUEST 923 }; 924 925 private: 926 volatile State _state; 927 928 private: 929 /* try to switch state from state "from" to state "to" 930 * returns the state set after the method is complete 931 */ 932 State switch_state(State from, State to); 933 934 public: 935 SuspendResume() : _state(SR_RUNNING) { } 936 937 State state() const { return _state; } 938 939 State request_suspend() { 940 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST); 941 } 942 943 State cancel_suspend() { 944 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING); 945 } 946 947 State suspended() { 948 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED); 949 } 950 951 State request_wakeup() { 952 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST); 953 } 954 955 State running() { 956 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING); 957 } 958 959 bool is_running() const { 960 return _state == SR_RUNNING; 961 } 962 963 bool is_suspend_request() const { 964 return _state == SR_SUSPEND_REQUEST; 965 } 966 967 bool is_suspended() const { 968 return _state == SR_SUSPENDED; 969 } 970 }; 971 #endif // !WINDOWS 972 973 974 protected: 975 static volatile unsigned int _rand_seed; // seed for random number generator 976 static int _processor_count; // number of processors 977 static int _initial_active_processor_count; // number of active processors during initialization. 978 979 static char* format_boot_path(const char* format_string, 980 const char* home, 981 int home_len, 982 char fileSep, 983 char pathSep); 984 static bool set_boot_path(char fileSep, char pathSep); 985 986 }; 987 988 // Note that "PAUSE" is almost always used with synchronization 989 // so arguably we should provide Atomic::SpinPause() instead 990 // of the global SpinPause() with C linkage. 991 // It'd also be eligible for inlining on many platforms. 992 993 extern "C" int SpinPause(); 994 995 #endif // SHARE_VM_RUNTIME_OS_HPP