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