1 /* 2 * Copyright (c) 1997, 2018, 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 "metaprogramming/isRegisteredEnum.hpp" 31 #include "metaprogramming/integralConstant.hpp" 32 #include "runtime/extendedPC.hpp" 33 #include "utilities/exceptions.hpp" 34 #include "utilities/ostream.hpp" 35 #include "utilities/macros.hpp" 36 #ifndef _WINDOWS 37 # include <setjmp.h> 38 #endif 39 #ifdef __APPLE__ 40 # include <mach/mach_time.h> 41 #endif 42 43 class AgentLibrary; 44 class frame; 45 46 // os defines the interface to operating system; this includes traditional 47 // OS services (time, I/O) as well as other functionality with system- 48 // dependent code. 49 50 typedef void (*dll_func)(...); 51 52 class Thread; 53 class JavaThread; 54 class Event; 55 class DLL; 56 class FileHandle; 57 class NativeCallStack; 58 class methodHandle; 59 60 template<class E> class GrowableArray; 61 62 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose 63 64 // Platform-independent error return values from OS functions 65 enum OSReturn { 66 OS_OK = 0, // Operation was successful 67 OS_ERR = -1, // Operation failed 68 OS_INTRPT = -2, // Operation was interrupted 69 OS_TIMEOUT = -3, // Operation timed out 70 OS_NOMEM = -5, // Operation failed for lack of memory 71 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource 72 }; 73 74 enum ThreadPriority { // JLS 20.20.1-3 75 NoPriority = -1, // Initial non-priority value 76 MinPriority = 1, // Minimum priority 77 NormPriority = 5, // Normal (non-daemon) priority 78 NearMaxPriority = 9, // High priority, used for VMThread 79 MaxPriority = 10, // Highest priority, used for WatcherThread 80 // ensures that VMThread doesn't starve profiler 81 CriticalPriority = 11 // Critical thread priority 82 }; 83 84 // Executable parameter flag for os::commit_memory() and 85 // os::commit_memory_or_exit(). 86 const bool ExecMem = true; 87 88 // Typedef for structured exception handling support 89 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread); 90 91 class MallocTracker; 92 93 class os: AllStatic { 94 friend class VMStructs; 95 friend class JVMCIVMStructs; 96 friend class MallocTracker; 97 public: 98 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel) 99 100 private: 101 static OSThread* _starting_thread; 102 static address _polling_page; 103 static volatile int32_t * _mem_serialize_page; 104 static uintptr_t _serialize_page_mask; 105 public: 106 static size_t _page_sizes[page_sizes_max]; 107 108 private: 109 static void init_page_sizes(size_t default_page_size) { 110 _page_sizes[0] = default_page_size; 111 _page_sizes[1] = 0; // sentinel 112 } 113 114 static char* pd_reserve_memory(size_t bytes, char* addr = 0, 115 size_t alignment_hint = 0); 116 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr); 117 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc); 118 static void pd_split_reserved_memory(char *base, size_t size, 119 size_t split, bool realloc); 120 static bool pd_commit_memory(char* addr, size_t bytes, bool executable); 121 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 122 bool executable); 123 // Same as pd_commit_memory() that either succeeds or calls 124 // vm_exit_out_of_memory() with the specified mesg. 125 static void pd_commit_memory_or_exit(char* addr, size_t bytes, 126 bool executable, const char* mesg); 127 static void pd_commit_memory_or_exit(char* addr, size_t size, 128 size_t alignment_hint, 129 bool executable, const char* mesg); 130 static bool pd_uncommit_memory(char* addr, size_t bytes); 131 static bool pd_release_memory(char* addr, size_t bytes); 132 133 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset, 134 char *addr, size_t bytes, bool read_only = false, 135 bool allow_exec = false); 136 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset, 137 char *addr, size_t bytes, bool read_only, 138 bool allow_exec); 139 static bool pd_unmap_memory(char *addr, size_t bytes); 140 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint); 141 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint); 142 143 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned); 144 145 // Get summary strings for system information in buffer provided 146 static void get_summary_cpu_info(char* buf, size_t buflen); 147 static void get_summary_os_info(char* buf, size_t buflen); 148 149 static void initialize_initial_active_processor_count(); 150 151 LINUX_ONLY(static void pd_init_container_support();) 152 153 public: 154 static void init(void); // Called before command line parsing 155 156 static void init_container_support() { // Called during command line parsing. 157 LINUX_ONLY(pd_init_container_support();) 158 } 159 160 static void init_before_ergo(void); // Called after command line parsing 161 // before VM ergonomics processing. 162 static jint init_2(void); // Called after command line parsing 163 // and VM ergonomics processing 164 static void init_globals(void) { // Called from init_globals() in init.cpp 165 init_globals_ext(); 166 } 167 168 // File names are case-insensitive on windows only 169 // Override me as needed 170 static int file_name_strncmp(const char* s1, const char* s2, size_t num); 171 172 // unset environment variable 173 static bool unsetenv(const char* name); 174 175 static bool have_special_privileges(); 176 177 static jlong javaTimeMillis(); 178 static jlong javaTimeNanos(); 179 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr); 180 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos); 181 static void run_periodic_checks(); 182 static bool supports_monotonic_clock(); 183 184 // Returns the elapsed time in seconds since the vm started. 185 static double elapsedTime(); 186 187 // Returns real time in seconds since an arbitrary point 188 // in the past. 189 static bool getTimesSecs(double* process_real_time, 190 double* process_user_time, 191 double* process_system_time); 192 193 // Interface to the performance counter 194 static jlong elapsed_counter(); 195 static jlong elapsed_frequency(); 196 197 // The "virtual time" of a thread is the amount of time a thread has 198 // actually run. The first function indicates whether the OS supports 199 // this functionality for the current thread, and if so: 200 // * the second enables vtime tracking (if that is required). 201 // * the third tells whether vtime is enabled. 202 // * the fourth returns the elapsed virtual time for the current 203 // thread. 204 static bool supports_vtime(); 205 static bool enable_vtime(); 206 static bool vtime_enabled(); 207 static double elapsedVTime(); 208 209 // Return current local time in a string (YYYY-MM-DD HH:MM:SS). 210 // It is MT safe, but not async-safe, as reading time zone 211 // information may require a lock on some platforms. 212 static char* local_time_string(char *buf, size_t buflen); 213 static struct tm* localtime_pd (const time_t* clock, struct tm* res); 214 static struct tm* gmtime_pd (const time_t* clock, struct tm* res); 215 // Fill in buffer with current local time as an ISO-8601 string. 216 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz. 217 // Returns buffer, or NULL if it failed. 218 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false); 219 220 // Interface for detecting multiprocessor system 221 static inline bool is_MP() { 222 // During bootstrap if _processor_count is not yet initialized 223 // we claim to be MP as that is safest. If any platform has a 224 // stub generator that might be triggered in this phase and for 225 // which being declared MP when in fact not, is a problem - then 226 // the bootstrap routine for the stub generator needs to check 227 // the processor count directly and leave the bootstrap routine 228 // in place until called after initialization has ocurred. 229 return AssumeMP || (_processor_count != 1); 230 } 231 static julong available_memory(); 232 static julong physical_memory(); 233 static bool has_allocatable_memory_limit(julong* limit); 234 static bool is_server_class_machine(); 235 236 // Returns the id of the processor on which the calling thread is currently executing. 237 // The returned value is guaranteed to be between 0 and (os::processor_count() - 1). 238 static uint processor_id(); 239 240 // number of CPUs 241 static int processor_count() { 242 return _processor_count; 243 } 244 static void set_processor_count(int count) { _processor_count = count; } 245 246 // Returns the number of CPUs this process is currently allowed to run on. 247 // Note that on some OSes this can change dynamically. 248 static int active_processor_count(); 249 250 // At startup the number of active CPUs this process is allowed to run on. 251 // This value does not change dynamically. May be different from active_processor_count(). 252 static int initial_active_processor_count() { 253 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet."); 254 return _initial_active_processor_count; 255 } 256 257 // Bind processes to processors. 258 // This is a two step procedure: 259 // first you generate a distribution of processes to processors, 260 // then you bind processes according to that distribution. 261 // Compute a distribution for number of processes to processors. 262 // Stores the processor id's into the distribution array argument. 263 // Returns true if it worked, false if it didn't. 264 static bool distribute_processes(uint length, uint* distribution); 265 // Binds the current process to a processor. 266 // Returns true if it worked, false if it didn't. 267 static bool bind_to_processor(uint processor_id); 268 269 // Give a name to the current thread. 270 static void set_native_thread_name(const char *name); 271 272 // Interface for stack banging (predetect possible stack overflow for 273 // exception processing) There are guard pages, and above that shadow 274 // pages for stack overflow checking. 275 static bool uses_stack_guard_pages(); 276 static bool must_commit_stack_guard_pages(); 277 static void map_stack_shadow_pages(address sp); 278 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp); 279 280 // Find committed memory region within specified range (start, start + size), 281 // return true if found any 282 static bool committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size); 283 284 // OS interface to Virtual Memory 285 286 // Return the default page size. 287 static int vm_page_size(); 288 289 // Returns the page size to use for a region of memory. 290 // region_size / min_pages will always be greater than or equal to the 291 // returned value. The returned value will divide region_size. 292 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages); 293 294 // Returns the page size to use for a region of memory. 295 // region_size / min_pages will always be greater than or equal to the 296 // returned value. The returned value might not divide region_size. 297 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages); 298 299 // Return the largest page size that can be used 300 static size_t max_page_size() { 301 // The _page_sizes array is sorted in descending order. 302 return _page_sizes[0]; 303 } 304 305 // Methods for tracing page sizes returned by the above method. 306 // The region_{min,max}_size parameters should be the values 307 // passed to page_size_for_region() and page_size should be the result of that 308 // call. The (optional) base and size parameters should come from the 309 // ReservedSpace base() and size() methods. 310 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count); 311 static void trace_page_sizes(const char* str, 312 const size_t region_min_size, 313 const size_t region_max_size, 314 const size_t page_size, 315 const char* base, 316 const size_t size); 317 static void trace_page_sizes_for_requested_size(const char* str, 318 const size_t requested_size, 319 const size_t page_size, 320 const size_t alignment, 321 const char* base, 322 const size_t size); 323 324 static int vm_allocation_granularity(); 325 static char* reserve_memory(size_t bytes, char* addr = 0, 326 size_t alignment_hint = 0, int file_desc = -1); 327 static char* reserve_memory(size_t bytes, char* addr, 328 size_t alignment_hint, MEMFLAGS flags); 329 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1); 330 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1); 331 static void split_reserved_memory(char *base, size_t size, 332 size_t split, bool realloc); 333 static bool commit_memory(char* addr, size_t bytes, bool executable); 334 static bool commit_memory(char* addr, size_t size, size_t alignment_hint, 335 bool executable); 336 // Same as commit_memory() that either succeeds or calls 337 // vm_exit_out_of_memory() with the specified mesg. 338 static void commit_memory_or_exit(char* addr, size_t bytes, 339 bool executable, const char* mesg); 340 static void commit_memory_or_exit(char* addr, size_t size, 341 size_t alignment_hint, 342 bool executable, const char* mesg); 343 static bool uncommit_memory(char* addr, size_t bytes); 344 static bool release_memory(char* addr, size_t bytes); 345 346 // Touch memory pages that cover the memory range from start to end (exclusive) 347 // to make the OS back the memory range with actual memory. 348 // Current implementation may not touch the last page if unaligned addresses 349 // are passed. 350 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size()); 351 352 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX }; 353 static bool protect_memory(char* addr, size_t bytes, ProtType prot, 354 bool is_committed = true); 355 356 static bool guard_memory(char* addr, size_t bytes); 357 static bool unguard_memory(char* addr, size_t bytes); 358 static bool create_stack_guard_pages(char* addr, size_t bytes); 359 static bool pd_create_stack_guard_pages(char* addr, size_t bytes); 360 static bool remove_stack_guard_pages(char* addr, size_t bytes); 361 // Helper function to create a new file with template jvmheap.XXXXXX. 362 // Returns a valid fd on success or else returns -1 363 static int create_file_for_heap(const char* dir); 364 // Map memory to the file referred by fd. This function is slightly different from map_memory() 365 // and is added to be used for implementation of -XX:AllocateHeapAt 366 static char* map_memory_to_file(char* base, size_t size, int fd); 367 // Replace existing reserved memory with file mapping 368 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd); 369 370 static char* map_memory(int fd, const char* file_name, size_t file_offset, 371 char *addr, size_t bytes, bool read_only = false, 372 bool allow_exec = false); 373 static char* remap_memory(int fd, const char* file_name, size_t file_offset, 374 char *addr, size_t bytes, bool read_only, 375 bool allow_exec); 376 static bool unmap_memory(char *addr, size_t bytes); 377 static void free_memory(char *addr, size_t bytes, size_t alignment_hint); 378 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint); 379 380 // NUMA-specific interface 381 static bool numa_has_static_binding(); 382 static bool numa_has_group_homing(); 383 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint); 384 static void numa_make_global(char *addr, size_t bytes); 385 static size_t numa_get_groups_num(); 386 static size_t numa_get_leaf_groups(int *ids, size_t size); 387 static bool numa_topology_changed(); 388 static int numa_get_group_id(); 389 390 // Page manipulation 391 struct page_info { 392 size_t size; 393 int lgrp_id; 394 }; 395 static bool get_page_info(char *start, page_info* info); 396 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found); 397 398 static char* non_memory_address_word(); 399 // reserve, commit and pin the entire memory region 400 static char* reserve_memory_special(size_t size, size_t alignment, 401 char* addr, bool executable); 402 static bool release_memory_special(char* addr, size_t bytes); 403 static void large_page_init(); 404 static size_t large_page_size(); 405 static bool can_commit_large_page_memory(); 406 static bool can_execute_large_page_memory(); 407 408 // OS interface to polling page 409 static address get_polling_page() { return _polling_page; } 410 static void set_polling_page(address page) { _polling_page = page; } 411 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); } 412 static void make_polling_page_unreadable(); 413 static void make_polling_page_readable(); 414 415 // Routines used to serialize the thread state without using membars 416 static void serialize_thread_states(); 417 418 // Since we write to the serialize page from every thread, we 419 // want stores to be on unique cache lines whenever possible 420 // in order to minimize CPU cross talk. We pre-compute the 421 // amount to shift the thread* to make this offset unique to 422 // each thread. 423 static int get_serialize_page_shift_count() { 424 return SerializePageShiftCount; 425 } 426 427 static void set_serialize_page_mask(uintptr_t mask) { 428 _serialize_page_mask = mask; 429 } 430 431 static unsigned int get_serialize_page_mask() { 432 return _serialize_page_mask; 433 } 434 435 static void set_memory_serialize_page(address page); 436 437 static address get_memory_serialize_page() { 438 return (address)_mem_serialize_page; 439 } 440 441 static inline void write_memory_serialize_page(JavaThread *thread) { 442 uintptr_t page_offset = ((uintptr_t)thread >> 443 get_serialize_page_shift_count()) & 444 get_serialize_page_mask(); 445 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1; 446 } 447 448 static bool is_memory_serialize_page(JavaThread *thread, address addr) { 449 if (UseMembar) return false; 450 // Previously this function calculated the exact address of this 451 // thread's serialize page, and checked if the faulting address 452 // was equal. However, some platforms mask off faulting addresses 453 // to the page size, so now we just check that the address is 454 // within the page. This makes the thread argument unnecessary, 455 // but we retain the NULL check to preserve existing behavior. 456 if (thread == NULL) return false; 457 address page = (address) _mem_serialize_page; 458 return addr >= page && addr < (page + os::vm_page_size()); 459 } 460 461 static void block_on_serialize_page_trap(); 462 463 // threads 464 465 enum ThreadType { 466 vm_thread, 467 cgc_thread, // Concurrent GC thread 468 pgc_thread, // Parallel GC thread 469 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads. 470 compiler_thread, 471 watcher_thread, 472 os_thread 473 }; 474 475 static bool create_thread(Thread* thread, 476 ThreadType thr_type, 477 size_t req_stack_size = 0); 478 479 // The "main thread", also known as "starting thread", is the thread 480 // that loads/creates the JVM via JNI_CreateJavaVM. 481 static bool create_main_thread(JavaThread* thread); 482 483 // The primordial thread is the initial process thread. The java 484 // launcher never uses the primordial thread as the main thread, but 485 // applications that host the JVM directly may do so. Some platforms 486 // need special-case handling of the primordial thread if it attaches 487 // to the VM. 488 static bool is_primordial_thread(void) 489 #if defined(_WINDOWS) || defined(BSD) 490 // No way to identify the primordial thread. 491 { return false; } 492 #else 493 ; 494 #endif 495 496 static bool create_attached_thread(JavaThread* thread); 497 static void pd_start_thread(Thread* thread); 498 static void start_thread(Thread* thread); 499 500 static void initialize_thread(Thread* thr); 501 static void free_thread(OSThread* osthread); 502 503 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit 504 static intx current_thread_id(); 505 static int current_process_id(); 506 static int sleep(Thread* thread, jlong ms, bool interruptable); 507 // Short standalone OS sleep suitable for slow path spin loop. 508 // Ignores Thread.interrupt() (so keep it short). 509 // ms = 0, will sleep for the least amount of time allowed by the OS. 510 static void naked_short_sleep(jlong ms); 511 static void infinite_sleep(); // never returns, use with CAUTION 512 static void naked_yield () ; 513 static OSReturn set_priority(Thread* thread, ThreadPriority priority); 514 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority); 515 516 static void interrupt(Thread* thread); 517 static bool is_interrupted(Thread* thread, bool clear_interrupted); 518 519 static int pd_self_suspend_thread(Thread* thread); 520 521 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp); 522 static frame fetch_frame_from_context(const void* ucVoid); 523 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid); 524 525 static void breakpoint(); 526 static bool start_debugging(char *buf, int buflen); 527 528 static address current_stack_pointer(); 529 static address current_stack_base(); 530 static size_t current_stack_size(); 531 532 static void verify_stack_alignment() PRODUCT_RETURN; 533 534 static bool message_box(const char* title, const char* message); 535 static char* do_you_want_to_debug(const char* message); 536 537 // run cmd in a separate process and return its exit code; or -1 on failures 538 static int fork_and_exec(char *cmd); 539 540 // Call ::exit() on all platforms but Windows 541 static void exit(int num); 542 543 // Terminate the VM, but don't exit the process 544 static void shutdown(); 545 546 // Terminate with an error. Default is to generate a core file on platforms 547 // that support such things. This calls shutdown() and then aborts. 548 static void abort(bool dump_core, void *siginfo, const void *context); 549 static void abort(bool dump_core = true); 550 551 // Die immediately, no exit hook, no abort hook, no cleanup. 552 static void die(); 553 554 // File i/o operations 555 static const int default_file_open_flags(); 556 static int open(const char *path, int oflag, int mode); 557 static FILE* open(int fd, const char* mode); 558 static FILE* fopen(const char* path, const char* mode); 559 static int close(int fd); 560 static jlong lseek(int fd, jlong offset, int whence); 561 static char* native_path(char *path); 562 static int ftruncate(int fd, jlong length); 563 static int fsync(int fd); 564 static int available(int fd, jlong *bytes); 565 static int get_fileno(FILE* fp); 566 static void flockfile(FILE* fp); 567 static void funlockfile(FILE* fp); 568 569 static int compare_file_modified_times(const char* file1, const char* file2); 570 571 //File i/o operations 572 573 static size_t read(int fd, void *buf, unsigned int nBytes); 574 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset); 575 static size_t restartable_read(int fd, void *buf, unsigned int nBytes); 576 static size_t write(int fd, const void *buf, unsigned int nBytes); 577 578 // Reading directories. 579 static DIR* opendir(const char* dirname); 580 static int readdir_buf_size(const char *path); 581 static struct dirent* readdir(DIR* dirp, dirent* dbuf); 582 static int closedir(DIR* dirp); 583 584 // Dynamic library extension 585 static const char* dll_file_extension(); 586 587 static const char* get_temp_directory(); 588 static const char* get_current_directory(char *buf, size_t buflen); 589 590 // Builds the platform-specific name of a library. 591 // Returns false if the buffer is too small. 592 static bool dll_build_name(char* buffer, size_t size, 593 const char* fname); 594 595 // Builds a platform-specific full library path given an ld path and 596 // unadorned library name. Returns true if the buffer contains a full 597 // path to an existing file, false otherwise. If pathname is empty, 598 // uses the path to the current directory. 599 static bool dll_locate_lib(char* buffer, size_t size, 600 const char* pathname, const char* fname); 601 602 // Symbol lookup, find nearest function name; basically it implements 603 // dladdr() for all platforms. Name of the nearest function is copied 604 // to buf. Distance from its base address is optionally returned as offset. 605 // If function name is not found, buf[0] is set to '\0' and offset is 606 // set to -1 (if offset is non-NULL). 607 static bool dll_address_to_function_name(address addr, char* buf, 608 int buflen, int* offset, 609 bool demangle = true); 610 611 // Locate DLL/DSO. On success, full path of the library is copied to 612 // buf, and offset is optionally set to be the distance between addr 613 // and the library's base address. On failure, buf[0] is set to '\0' 614 // and offset is set to -1 (if offset is non-NULL). 615 static bool dll_address_to_library_name(address addr, char* buf, 616 int buflen, int* offset); 617 618 // Find out whether the pc is in the static code for jvm.dll/libjvm.so. 619 static bool address_is_in_vm(address addr); 620 621 // Loads .dll/.so and 622 // in case of error it checks if .dll/.so was built for the 623 // same architecture as HotSpot is running on 624 static void* dll_load(const char *name, char *ebuf, int ebuflen); 625 626 // lookup symbol in a shared library 627 static void* dll_lookup(void* handle, const char* name); 628 629 // Unload library 630 static void dll_unload(void *lib); 631 632 // Callback for loaded module information 633 // Input parameters: 634 // char* module_file_name, 635 // address module_base_addr, 636 // address module_top_addr, 637 // void* param 638 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *); 639 640 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param); 641 642 // Return the handle of this process 643 static void* get_default_process_handle(); 644 645 // Check for static linked agent library 646 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 647 size_t syms_len); 648 649 // Find agent entry point 650 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib, 651 const char *syms[], size_t syms_len); 652 653 // Provide C99 compliant versions of these functions, since some versions 654 // of some platforms don't. 655 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0); 656 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4); 657 658 // Get host name in buffer provided 659 static bool get_host_name(char* buf, size_t buflen); 660 661 // Print out system information; they are called by fatal error handler. 662 // Output format may be different on different platforms. 663 static void print_os_info(outputStream* st); 664 static void print_os_info_brief(outputStream* st); 665 static void print_cpu_info(outputStream* st, char* buf, size_t buflen); 666 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen); 667 static void print_summary_info(outputStream* st, char* buf, size_t buflen); 668 static void print_memory_info(outputStream* st); 669 static void print_dll_info(outputStream* st); 670 static void print_environment_variables(outputStream* st, const char** env_list); 671 static void print_context(outputStream* st, const void* context); 672 static void print_register_info(outputStream* st, const void* context); 673 static void print_siginfo(outputStream* st, const void* siginfo); 674 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen); 675 static void print_date_and_time(outputStream* st, char* buf, size_t buflen); 676 677 static void print_location(outputStream* st, intptr_t x, bool verbose = false); 678 static size_t lasterror(char *buf, size_t len); 679 static int get_last_error(); 680 681 // Replacement for strerror(). 682 // Will return the english description of the error (e.g. "File not found", as 683 // suggested in the POSIX standard. 684 // Will return "Unknown error" for an unknown errno value. 685 // Will not attempt to localize the returned string. 686 // Will always return a valid string which is a static constant. 687 // Will not change the value of errno. 688 static const char* strerror(int e); 689 690 // Will return the literalized version of the given errno (e.g. "EINVAL" 691 // for EINVAL). 692 // Will return "Unknown error" for an unknown errno value. 693 // Will always return a valid string which is a static constant. 694 // Will not change the value of errno. 695 static const char* errno_name(int e); 696 697 // Determines whether the calling process is being debugged by a user-mode debugger. 698 static bool is_debugger_attached(); 699 700 // wait for a key press if PauseAtExit is set 701 static void wait_for_keypress_at_exit(void); 702 703 // The following two functions are used by fatal error handler to trace 704 // native (C) frames. They are not part of frame.hpp/frame.cpp because 705 // frame.hpp/cpp assume thread is JavaThread, and also because different 706 // OS/compiler may have different convention or provide different API to 707 // walk C frames. 708 // 709 // We don't attempt to become a debugger, so we only follow frames if that 710 // does not require a lookup in the unwind table, which is part of the binary 711 // file but may be unsafe to read after a fatal error. So on x86, we can 712 // only walk stack if %ebp is used as frame pointer; on ia64, it's not 713 // possible to walk C stack without having the unwind table. 714 static bool is_first_C_frame(frame *fr); 715 static frame get_sender_for_C_frame(frame *fr); 716 717 // return current frame. pc() and sp() are set to NULL on failure. 718 static frame current_frame(); 719 720 static void print_hex_dump(outputStream* st, address start, address end, int unitsize); 721 722 // returns a string to describe the exception/signal; 723 // returns NULL if exception_code is not an OS exception/signal. 724 static const char* exception_name(int exception_code, char* buf, size_t buflen); 725 726 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV). 727 static int get_signal_number(const char* signal_name); 728 729 // Returns native Java library, loads if necessary 730 static void* native_java_library(); 731 732 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler) 733 static void jvm_path(char *buf, jint buflen); 734 735 // JNI names 736 static void print_jni_name_prefix_on(outputStream* st, int args_size); 737 static void print_jni_name_suffix_on(outputStream* st, int args_size); 738 739 // Init os specific system properties values 740 static void init_system_properties_values(); 741 742 // IO operations, non-JVM_ version. 743 static int stat(const char* path, struct stat* sbuf); 744 static bool dir_is_empty(const char* path); 745 746 // IO operations on binary files 747 static int create_binary_file(const char* path, bool rewrite_existing); 748 static jlong current_file_offset(int fd); 749 static jlong seek_to_file_offset(int fd, jlong offset); 750 751 // Retrieve native stack frames. 752 // Parameter: 753 // stack: an array to storage stack pointers. 754 // frames: size of above array. 755 // toSkip: number of stack frames to skip at the beginning. 756 // Return: number of stack frames captured. 757 static int get_native_stack(address* stack, int size, int toSkip = 0); 758 759 // General allocation (must be MT-safe) 760 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack); 761 static void* malloc (size_t size, MEMFLAGS flags); 762 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack); 763 static void* realloc (void *memblock, size_t size, MEMFLAGS flag); 764 765 static void free (void *memblock); 766 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup 767 // Like strdup, but exit VM when strdup() returns NULL 768 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal); 769 770 #ifndef PRODUCT 771 static julong num_mallocs; // # of calls to malloc/realloc 772 static julong alloc_bytes; // # of bytes allocated 773 static julong num_frees; // # of calls to free 774 static julong free_bytes; // # of bytes freed 775 #endif 776 777 // SocketInterface (ex HPI SocketInterface ) 778 static int socket(int domain, int type, int protocol); 779 static int socket_close(int fd); 780 static int recv(int fd, char* buf, size_t nBytes, uint flags); 781 static int send(int fd, char* buf, size_t nBytes, uint flags); 782 static int raw_send(int fd, char* buf, size_t nBytes, uint flags); 783 static int connect(int fd, struct sockaddr* him, socklen_t len); 784 static struct hostent* get_host_by_name(char* name); 785 786 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal) 787 static void initialize_jdk_signal_support(TRAPS); 788 static void signal_notify(int signal_number); 789 static void* signal(int signal_number, void* handler); 790 static void signal_raise(int signal_number); 791 static int signal_wait(); 792 static void* user_handler(); 793 static void terminate_signal_thread(); 794 static int sigexitnum_pd(); 795 796 // random number generation 797 static int random(); // return 32bit pseudorandom number 798 static void init_random(unsigned int initval); // initialize random sequence 799 800 // Structured OS Exception support 801 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread); 802 803 // On Posix compatible OS it will simply check core dump limits while on Windows 804 // it will check if dump file can be created. Check or prepare a core dump to be 805 // taken at a later point in the same thread in os::abort(). Use the caller 806 // provided buffer as a scratch buffer. The status message which will be written 807 // into the error log either is file location or a short error message, depending 808 // on the checking result. 809 static void check_dump_limit(char* buffer, size_t bufferSize); 810 811 // Get the default path to the core file 812 // Returns the length of the string 813 static int get_core_path(char* buffer, size_t bufferSize); 814 815 // JVMTI & JVM monitoring and management support 816 // The thread_cpu_time() and current_thread_cpu_time() are only 817 // supported if is_thread_cpu_time_supported() returns true. 818 // They are not supported on Solaris T1. 819 820 // Thread CPU Time - return the fast estimate on a platform 821 // On Solaris - call gethrvtime (fast) - user time only 822 // On Linux - fast clock_gettime where available - user+sys 823 // - otherwise: very slow /proc fs - user+sys 824 // On Windows - GetThreadTimes - user+sys 825 static jlong current_thread_cpu_time(); 826 static jlong thread_cpu_time(Thread* t); 827 828 // Thread CPU Time with user_sys_cpu_time parameter. 829 // 830 // If user_sys_cpu_time is true, user+sys time is returned. 831 // Otherwise, only user time is returned 832 static jlong current_thread_cpu_time(bool user_sys_cpu_time); 833 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time); 834 835 // Return a bunch of info about the timers. 836 // Note that the returned info for these two functions may be different 837 // on some platforms 838 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 839 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 840 841 static bool is_thread_cpu_time_supported(); 842 843 // System loadavg support. Returns -1 if load average cannot be obtained. 844 static int loadavg(double loadavg[], int nelem); 845 846 // Hook for os specific jvm options that we don't want to abort on seeing 847 static bool obsolete_option(const JavaVMOption *option); 848 849 // Amount beyond the callee frame size that we bang the stack. 850 static int extra_bang_size_in_bytes(); 851 852 static char** split_path(const char* path, int* n); 853 854 // Extensions 855 #include "runtime/os_ext.hpp" 856 857 public: 858 class CrashProtectionCallback : public StackObj { 859 public: 860 virtual void call() = 0; 861 }; 862 863 // Platform dependent stuff 864 #ifndef _WINDOWS 865 # include "os_posix.hpp" 866 #endif 867 #include OS_CPU_HEADER(os) 868 #include OS_HEADER(os) 869 870 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG 871 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached" 872 #endif 873 874 public: 875 #ifndef PLATFORM_PRINT_NATIVE_STACK 876 // No platform-specific code for printing the native stack. 877 static bool platform_print_native_stack(outputStream* st, const void* context, 878 char *buf, int buf_size) { 879 return false; 880 } 881 #endif 882 883 // debugging support (mostly used by debug.cpp but also fatal error handler) 884 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address 885 886 static bool dont_yield(); // when true, JVM_Yield() is nop 887 static void print_statistics(); 888 889 // Thread priority helpers (implemented in OS-specific part) 890 static OSReturn set_native_priority(Thread* thread, int native_prio); 891 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr); 892 static int java_to_os_priority[CriticalPriority + 1]; 893 // Hint to the underlying OS that a task switch would not be good. 894 // Void return because it's a hint and can fail. 895 static void hint_no_preempt(); 896 static const char* native_thread_creation_failed_msg() { 897 return OS_NATIVE_THREAD_CREATION_FAILED_MSG; 898 } 899 900 // Used at creation if requested by the diagnostic flag PauseAtStartup. 901 // Causes the VM to wait until an external stimulus has been applied 902 // (for Unix, that stimulus is a signal, for Windows, an external 903 // ResumeThread call) 904 static void pause(); 905 906 // Builds a platform dependent Agent_OnLoad_<libname> function name 907 // which is used to find statically linked in agents. 908 static char* build_agent_function_name(const char *sym, const char *cname, 909 bool is_absolute_path); 910 911 class SuspendedThreadTaskContext { 912 public: 913 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {} 914 Thread* thread() const { return _thread; } 915 void* ucontext() const { return _ucontext; } 916 private: 917 Thread* _thread; 918 void* _ucontext; 919 }; 920 921 class SuspendedThreadTask { 922 public: 923 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {} 924 void run(); 925 bool is_done() { return _done; } 926 virtual void do_task(const SuspendedThreadTaskContext& context) = 0; 927 protected: 928 ~SuspendedThreadTask() {} 929 private: 930 void internal_do_task(); 931 Thread* _thread; 932 bool _done; 933 }; 934 935 #ifndef _WINDOWS 936 // Suspend/resume support 937 // Protocol: 938 // 939 // a thread starts in SR_RUNNING 940 // 941 // SR_RUNNING can go to 942 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it 943 // SR_SUSPEND_REQUEST can go to 944 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout) 945 // * SR_SUSPENDED if the stopped thread receives the signal and switches state 946 // SR_SUSPENDED can go to 947 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume 948 // SR_WAKEUP_REQUEST can go to 949 // * SR_RUNNING when the stopped thread receives the signal 950 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again) 951 class SuspendResume { 952 public: 953 enum State { 954 SR_RUNNING, 955 SR_SUSPEND_REQUEST, 956 SR_SUSPENDED, 957 SR_WAKEUP_REQUEST 958 }; 959 960 private: 961 volatile State _state; 962 963 private: 964 /* try to switch state from state "from" to state "to" 965 * returns the state set after the method is complete 966 */ 967 State switch_state(State from, State to); 968 969 public: 970 SuspendResume() : _state(SR_RUNNING) { } 971 972 State state() const { return _state; } 973 974 State request_suspend() { 975 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST); 976 } 977 978 State cancel_suspend() { 979 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING); 980 } 981 982 State suspended() { 983 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED); 984 } 985 986 State request_wakeup() { 987 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST); 988 } 989 990 State running() { 991 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING); 992 } 993 994 bool is_running() const { 995 return _state == SR_RUNNING; 996 } 997 998 bool is_suspend_request() const { 999 return _state == SR_SUSPEND_REQUEST; 1000 } 1001 1002 bool is_suspended() const { 1003 return _state == SR_SUSPENDED; 1004 } 1005 }; 1006 #endif // !WINDOWS 1007 1008 1009 protected: 1010 static volatile unsigned int _rand_seed; // seed for random number generator 1011 static int _processor_count; // number of processors 1012 static int _initial_active_processor_count; // number of active processors during initialization. 1013 1014 static char* format_boot_path(const char* format_string, 1015 const char* home, 1016 int home_len, 1017 char fileSep, 1018 char pathSep); 1019 static bool set_boot_path(char fileSep, char pathSep); 1020 1021 }; 1022 1023 #ifndef _WINDOWS 1024 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {}; 1025 #endif // !_WINDOWS 1026 1027 // Note that "PAUSE" is almost always used with synchronization 1028 // so arguably we should provide Atomic::SpinPause() instead 1029 // of the global SpinPause() with C linkage. 1030 // It'd also be eligible for inlining on many platforms. 1031 1032 extern "C" int SpinPause(); 1033 1034 #endif // SHARE_VM_RUNTIME_OS_HPP