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 (_processor_count != 1); 230 } 231 232 static julong available_memory(); 233 static julong physical_memory(); 234 static bool has_allocatable_memory_limit(julong* limit); 235 static bool is_server_class_machine(); 236 237 // Returns the id of the processor on which the calling thread is currently executing. 238 // The returned value is guaranteed to be between 0 and (os::processor_count() - 1). 239 static uint processor_id(); 240 241 // number of CPUs 242 static int processor_count() { 243 return _processor_count; 244 } 245 static void set_processor_count(int count) { _processor_count = count; } 246 247 // Returns the number of CPUs this process is currently allowed to run on. 248 // Note that on some OSes this can change dynamically. 249 static int active_processor_count(); 250 251 // At startup the number of active CPUs this process is allowed to run on. 252 // This value does not change dynamically. May be different from active_processor_count(). 253 static int initial_active_processor_count() { 254 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet."); 255 return _initial_active_processor_count; 256 } 257 258 // Bind processes to processors. 259 // This is a two step procedure: 260 // first you generate a distribution of processes to processors, 261 // then you bind processes according to that distribution. 262 // Compute a distribution for number of processes to processors. 263 // Stores the processor id's into the distribution array argument. 264 // Returns true if it worked, false if it didn't. 265 static bool distribute_processes(uint length, uint* distribution); 266 // Binds the current process to a processor. 267 // Returns true if it worked, false if it didn't. 268 static bool bind_to_processor(uint processor_id); 269 270 // Give a name to the current thread. 271 static void set_native_thread_name(const char *name); 272 273 // Interface for stack banging (predetect possible stack overflow for 274 // exception processing) There are guard pages, and above that shadow 275 // pages for stack overflow checking. 276 static bool uses_stack_guard_pages(); 277 static bool must_commit_stack_guard_pages(); 278 static void map_stack_shadow_pages(address sp); 279 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp); 280 281 // Find committed memory region within specified range (start, start + size), 282 // return true if found any 283 static bool committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size); 284 285 // OS interface to Virtual Memory 286 287 // Return the default page size. 288 static int vm_page_size(); 289 290 // Returns the page size to use for a region of memory. 291 // region_size / min_pages will always be greater than or equal to the 292 // returned value. The returned value will divide region_size. 293 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages); 294 295 // Returns the page size to use for a region of memory. 296 // region_size / min_pages will always be greater than or equal to the 297 // returned value. The returned value might not divide region_size. 298 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages); 299 300 // Return the largest page size that can be used 301 static size_t max_page_size() { 302 // The _page_sizes array is sorted in descending order. 303 return _page_sizes[0]; 304 } 305 306 // Methods for tracing page sizes returned by the above method. 307 // The region_{min,max}_size parameters should be the values 308 // passed to page_size_for_region() and page_size should be the result of that 309 // call. The (optional) base and size parameters should come from the 310 // ReservedSpace base() and size() methods. 311 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count); 312 static void trace_page_sizes(const char* str, 313 const size_t region_min_size, 314 const size_t region_max_size, 315 const size_t page_size, 316 const char* base, 317 const size_t size); 318 static void trace_page_sizes_for_requested_size(const char* str, 319 const size_t requested_size, 320 const size_t page_size, 321 const size_t alignment, 322 const char* base, 323 const size_t size); 324 325 static int vm_allocation_granularity(); 326 static char* reserve_memory(size_t bytes, char* addr = 0, 327 size_t alignment_hint = 0, int file_desc = -1); 328 static char* reserve_memory(size_t bytes, char* addr, 329 size_t alignment_hint, MEMFLAGS flags); 330 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1); 331 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1); 332 static void split_reserved_memory(char *base, size_t size, 333 size_t split, bool realloc); 334 static bool commit_memory(char* addr, size_t bytes, bool executable); 335 static bool commit_memory(char* addr, size_t size, size_t alignment_hint, 336 bool executable); 337 // Same as commit_memory() that either succeeds or calls 338 // vm_exit_out_of_memory() with the specified mesg. 339 static void commit_memory_or_exit(char* addr, size_t bytes, 340 bool executable, const char* mesg); 341 static void commit_memory_or_exit(char* addr, size_t size, 342 size_t alignment_hint, 343 bool executable, const char* mesg); 344 static bool uncommit_memory(char* addr, size_t bytes); 345 static bool release_memory(char* addr, size_t bytes); 346 347 // Touch memory pages that cover the memory range from start to end (exclusive) 348 // to make the OS back the memory range with actual memory. 349 // Current implementation may not touch the last page if unaligned addresses 350 // are passed. 351 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size()); 352 353 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX }; 354 static bool protect_memory(char* addr, size_t bytes, ProtType prot, 355 bool is_committed = true); 356 357 static bool guard_memory(char* addr, size_t bytes); 358 static bool unguard_memory(char* addr, size_t bytes); 359 static bool create_stack_guard_pages(char* addr, size_t bytes); 360 static bool pd_create_stack_guard_pages(char* addr, size_t bytes); 361 static bool remove_stack_guard_pages(char* addr, size_t bytes); 362 // Helper function to create a new file with template jvmheap.XXXXXX. 363 // Returns a valid fd on success or else returns -1 364 static int create_file_for_heap(const char* dir); 365 // Map memory to the file referred by fd. This function is slightly different from map_memory() 366 // and is added to be used for implementation of -XX:AllocateHeapAt 367 static char* map_memory_to_file(char* base, size_t size, int fd); 368 // Replace existing reserved memory with file mapping 369 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd); 370 371 static char* map_memory(int fd, const char* file_name, size_t file_offset, 372 char *addr, size_t bytes, bool read_only = false, 373 bool allow_exec = false); 374 static char* remap_memory(int fd, const char* file_name, size_t file_offset, 375 char *addr, size_t bytes, bool read_only, 376 bool allow_exec); 377 static bool unmap_memory(char *addr, size_t bytes); 378 static void free_memory(char *addr, size_t bytes, size_t alignment_hint); 379 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint); 380 381 // NUMA-specific interface 382 static bool numa_has_static_binding(); 383 static bool numa_has_group_homing(); 384 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint); 385 static void numa_make_global(char *addr, size_t bytes); 386 static size_t numa_get_groups_num(); 387 static size_t numa_get_leaf_groups(int *ids, size_t size); 388 static bool numa_topology_changed(); 389 static int numa_get_group_id(); 390 391 // Page manipulation 392 struct page_info { 393 size_t size; 394 int lgrp_id; 395 }; 396 static bool get_page_info(char *start, page_info* info); 397 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found); 398 399 static char* non_memory_address_word(); 400 // reserve, commit and pin the entire memory region 401 static char* reserve_memory_special(size_t size, size_t alignment, 402 char* addr, bool executable); 403 static bool release_memory_special(char* addr, size_t bytes); 404 static void large_page_init(); 405 static size_t large_page_size(); 406 static bool can_commit_large_page_memory(); 407 static bool can_execute_large_page_memory(); 408 409 // OS interface to polling page 410 static address get_polling_page() { return _polling_page; } 411 static void set_polling_page(address page) { _polling_page = page; } 412 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); } 413 static void make_polling_page_unreadable(); 414 static void make_polling_page_readable(); 415 416 // Check if pointer points to readable memory (by 4-byte read access) 417 static bool is_readable_pointer(const void* p); 418 419 // Routines used to serialize the thread state without using membars 420 static void serialize_thread_states(); 421 422 // Since we write to the serialize page from every thread, we 423 // want stores to be on unique cache lines whenever possible 424 // in order to minimize CPU cross talk. We pre-compute the 425 // amount to shift the thread* to make this offset unique to 426 // each thread. 427 static int get_serialize_page_shift_count() { 428 return SerializePageShiftCount; 429 } 430 431 static void set_serialize_page_mask(uintptr_t mask) { 432 _serialize_page_mask = mask; 433 } 434 435 static unsigned int get_serialize_page_mask() { 436 return _serialize_page_mask; 437 } 438 439 static void set_memory_serialize_page(address page); 440 441 static address get_memory_serialize_page() { 442 return (address)_mem_serialize_page; 443 } 444 445 static inline void write_memory_serialize_page(JavaThread *thread) { 446 uintptr_t page_offset = ((uintptr_t)thread >> 447 get_serialize_page_shift_count()) & 448 get_serialize_page_mask(); 449 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1; 450 } 451 452 static bool is_memory_serialize_page(JavaThread *thread, address addr) { 453 if (UseMembar) return false; 454 // Previously this function calculated the exact address of this 455 // thread's serialize page, and checked if the faulting address 456 // was equal. However, some platforms mask off faulting addresses 457 // to the page size, so now we just check that the address is 458 // within the page. This makes the thread argument unnecessary, 459 // but we retain the NULL check to preserve existing behavior. 460 if (thread == NULL) return false; 461 address page = (address) _mem_serialize_page; 462 return addr >= page && addr < (page + os::vm_page_size()); 463 } 464 465 static void block_on_serialize_page_trap(); 466 467 // threads 468 469 enum ThreadType { 470 vm_thread, 471 cgc_thread, // Concurrent GC thread 472 pgc_thread, // Parallel GC thread 473 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads. 474 compiler_thread, 475 watcher_thread, 476 os_thread 477 }; 478 479 static bool create_thread(Thread* thread, 480 ThreadType thr_type, 481 size_t req_stack_size = 0); 482 483 // The "main thread", also known as "starting thread", is the thread 484 // that loads/creates the JVM via JNI_CreateJavaVM. 485 static bool create_main_thread(JavaThread* thread); 486 487 // The primordial thread is the initial process thread. The java 488 // launcher never uses the primordial thread as the main thread, but 489 // applications that host the JVM directly may do so. Some platforms 490 // need special-case handling of the primordial thread if it attaches 491 // to the VM. 492 static bool is_primordial_thread(void) 493 #if defined(_WINDOWS) || defined(BSD) 494 // No way to identify the primordial thread. 495 { return false; } 496 #else 497 ; 498 #endif 499 500 static bool create_attached_thread(JavaThread* thread); 501 static void pd_start_thread(Thread* thread); 502 static void start_thread(Thread* thread); 503 504 static void initialize_thread(Thread* thr); 505 static void free_thread(OSThread* osthread); 506 507 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit 508 static intx current_thread_id(); 509 static int current_process_id(); 510 static int sleep(Thread* thread, jlong ms, bool interruptable); 511 // Short standalone OS sleep suitable for slow path spin loop. 512 // Ignores Thread.interrupt() (so keep it short). 513 // ms = 0, will sleep for the least amount of time allowed by the OS. 514 static void naked_short_sleep(jlong ms); 515 static void infinite_sleep(); // never returns, use with CAUTION 516 static void naked_yield () ; 517 static OSReturn set_priority(Thread* thread, ThreadPriority priority); 518 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority); 519 520 static void interrupt(Thread* thread); 521 static bool is_interrupted(Thread* thread, bool clear_interrupted); 522 523 static int pd_self_suspend_thread(Thread* thread); 524 525 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp); 526 static frame fetch_frame_from_context(const void* ucVoid); 527 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid); 528 529 static void breakpoint(); 530 static bool start_debugging(char *buf, int buflen); 531 532 static address current_stack_pointer(); 533 static address current_stack_base(); 534 static size_t current_stack_size(); 535 536 static void verify_stack_alignment() PRODUCT_RETURN; 537 538 static bool message_box(const char* title, const char* message); 539 static char* do_you_want_to_debug(const char* message); 540 541 // run cmd in a separate process and return its exit code; or -1 on failures 542 static int fork_and_exec(char *cmd); 543 544 // Call ::exit() on all platforms but Windows 545 static void exit(int num); 546 547 // Terminate the VM, but don't exit the process 548 static void shutdown(); 549 550 // Terminate with an error. Default is to generate a core file on platforms 551 // that support such things. This calls shutdown() and then aborts. 552 static void abort(bool dump_core, void *siginfo, const void *context); 553 static void abort(bool dump_core = true); 554 555 // Die immediately, no exit hook, no abort hook, no cleanup. 556 static void die(); 557 558 // File i/o operations 559 static const int default_file_open_flags(); 560 static int open(const char *path, int oflag, int mode); 561 static FILE* open(int fd, const char* mode); 562 static FILE* fopen(const char* path, const char* mode); 563 static int close(int fd); 564 static jlong lseek(int fd, jlong offset, int whence); 565 // This function, on Windows, canonicalizes a given path (see os_windows.cpp for details). 566 // On Posix, this function is a noop: it does not change anything and just returns 567 // the input pointer. 568 static char* native_path(char *path); 569 static int ftruncate(int fd, jlong length); 570 static int fsync(int fd); 571 static int available(int fd, jlong *bytes); 572 static int get_fileno(FILE* fp); 573 static void flockfile(FILE* fp); 574 static void funlockfile(FILE* fp); 575 576 static int compare_file_modified_times(const char* file1, const char* file2); 577 578 //File i/o operations 579 580 static size_t read(int fd, void *buf, unsigned int nBytes); 581 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset); 582 static size_t restartable_read(int fd, void *buf, unsigned int nBytes); 583 static size_t write(int fd, const void *buf, unsigned int nBytes); 584 585 // Reading directories. 586 static DIR* opendir(const char* dirname); 587 static struct dirent* readdir(DIR* dirp); 588 static int closedir(DIR* dirp); 589 590 // Dynamic library extension 591 static const char* dll_file_extension(); 592 593 static const char* get_temp_directory(); 594 static const char* get_current_directory(char *buf, size_t buflen); 595 596 // Builds the platform-specific name of a library. 597 // Returns false if the buffer is too small. 598 static bool dll_build_name(char* buffer, size_t size, 599 const char* fname); 600 601 // Builds a platform-specific full library path given an ld path and 602 // unadorned library name. Returns true if the buffer contains a full 603 // path to an existing file, false otherwise. If pathname is empty, 604 // uses the path to the current directory. 605 static bool dll_locate_lib(char* buffer, size_t size, 606 const char* pathname, const char* fname); 607 608 // Symbol lookup, find nearest function name; basically it implements 609 // dladdr() for all platforms. Name of the nearest function is copied 610 // to buf. Distance from its base address is optionally returned as offset. 611 // If function name is not found, buf[0] is set to '\0' and offset is 612 // set to -1 (if offset is non-NULL). 613 static bool dll_address_to_function_name(address addr, char* buf, 614 int buflen, int* offset, 615 bool demangle = true); 616 617 // Locate DLL/DSO. On success, full path of the library is copied to 618 // buf, and offset is optionally set to be the distance between addr 619 // and the library's base address. On failure, buf[0] is set to '\0' 620 // and offset is set to -1 (if offset is non-NULL). 621 static bool dll_address_to_library_name(address addr, char* buf, 622 int buflen, int* offset); 623 624 // Find out whether the pc is in the static code for jvm.dll/libjvm.so. 625 static bool address_is_in_vm(address addr); 626 627 // Loads .dll/.so and 628 // in case of error it checks if .dll/.so was built for the 629 // same architecture as HotSpot is running on 630 static void* dll_load(const char *name, char *ebuf, int ebuflen); 631 632 // lookup symbol in a shared library 633 static void* dll_lookup(void* handle, const char* name); 634 635 // Unload library 636 static void dll_unload(void *lib); 637 638 // Callback for loaded module information 639 // Input parameters: 640 // char* module_file_name, 641 // address module_base_addr, 642 // address module_top_addr, 643 // void* param 644 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *); 645 646 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param); 647 648 // Return the handle of this process 649 static void* get_default_process_handle(); 650 651 // Check for static linked agent library 652 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 653 size_t syms_len); 654 655 // Find agent entry point 656 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib, 657 const char *syms[], size_t syms_len); 658 659 // Provide C99 compliant versions of these functions, since some versions 660 // of some platforms don't. 661 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0); 662 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4); 663 664 // Get host name in buffer provided 665 static bool get_host_name(char* buf, size_t buflen); 666 667 // Print out system information; they are called by fatal error handler. 668 // Output format may be different on different platforms. 669 static void print_os_info(outputStream* st); 670 static void print_os_info_brief(outputStream* st); 671 static void print_cpu_info(outputStream* st, char* buf, size_t buflen); 672 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen); 673 static void print_summary_info(outputStream* st, char* buf, size_t buflen); 674 static void print_memory_info(outputStream* st); 675 static void print_dll_info(outputStream* st); 676 static void print_environment_variables(outputStream* st, const char** env_list); 677 static void print_context(outputStream* st, const void* context); 678 static void print_register_info(outputStream* st, const void* context); 679 static void print_siginfo(outputStream* st, const void* siginfo); 680 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen); 681 static void print_date_and_time(outputStream* st, char* buf, size_t buflen); 682 683 static void print_location(outputStream* st, intptr_t x, bool verbose = false); 684 static size_t lasterror(char *buf, size_t len); 685 static int get_last_error(); 686 687 // Replacement for strerror(). 688 // Will return the english description of the error (e.g. "File not found", as 689 // suggested in the POSIX standard. 690 // Will return "Unknown error" for an unknown errno value. 691 // Will not attempt to localize the returned string. 692 // Will always return a valid string which is a static constant. 693 // Will not change the value of errno. 694 static const char* strerror(int e); 695 696 // Will return the literalized version of the given errno (e.g. "EINVAL" 697 // for EINVAL). 698 // Will return "Unknown error" for an unknown errno value. 699 // Will always return a valid string which is a static constant. 700 // Will not change the value of errno. 701 static const char* errno_name(int e); 702 703 // Determines whether the calling process is being debugged by a user-mode debugger. 704 static bool is_debugger_attached(); 705 706 // wait for a key press if PauseAtExit is set 707 static void wait_for_keypress_at_exit(void); 708 709 // The following two functions are used by fatal error handler to trace 710 // native (C) frames. They are not part of frame.hpp/frame.cpp because 711 // frame.hpp/cpp assume thread is JavaThread, and also because different 712 // OS/compiler may have different convention or provide different API to 713 // walk C frames. 714 // 715 // We don't attempt to become a debugger, so we only follow frames if that 716 // does not require a lookup in the unwind table, which is part of the binary 717 // file but may be unsafe to read after a fatal error. So on x86, we can 718 // only walk stack if %ebp is used as frame pointer; on ia64, it's not 719 // possible to walk C stack without having the unwind table. 720 static bool is_first_C_frame(frame *fr); 721 static frame get_sender_for_C_frame(frame *fr); 722 723 // return current frame. pc() and sp() are set to NULL on failure. 724 static frame current_frame(); 725 726 static void print_hex_dump(outputStream* st, address start, address end, int unitsize); 727 728 // returns a string to describe the exception/signal; 729 // returns NULL if exception_code is not an OS exception/signal. 730 static const char* exception_name(int exception_code, char* buf, size_t buflen); 731 732 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV). 733 static int get_signal_number(const char* signal_name); 734 735 // Returns native Java library, loads if necessary 736 static void* native_java_library(); 737 738 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler) 739 static void jvm_path(char *buf, jint buflen); 740 741 // JNI names 742 static void print_jni_name_prefix_on(outputStream* st, int args_size); 743 static void print_jni_name_suffix_on(outputStream* st, int args_size); 744 745 // Init os specific system properties values 746 static void init_system_properties_values(); 747 748 // IO operations, non-JVM_ version. 749 static int stat(const char* path, struct stat* sbuf); 750 static bool dir_is_empty(const char* path); 751 752 // IO operations on binary files 753 static int create_binary_file(const char* path, bool rewrite_existing); 754 static jlong current_file_offset(int fd); 755 static jlong seek_to_file_offset(int fd, jlong offset); 756 757 // Retrieve native stack frames. 758 // Parameter: 759 // stack: an array to storage stack pointers. 760 // frames: size of above array. 761 // toSkip: number of stack frames to skip at the beginning. 762 // Return: number of stack frames captured. 763 static int get_native_stack(address* stack, int size, int toSkip = 0); 764 765 // General allocation (must be MT-safe) 766 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack); 767 static void* malloc (size_t size, MEMFLAGS flags); 768 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack); 769 static void* realloc (void *memblock, size_t size, MEMFLAGS flag); 770 771 static void free (void *memblock); 772 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup 773 // Like strdup, but exit VM when strdup() returns NULL 774 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal); 775 776 #ifndef PRODUCT 777 static julong num_mallocs; // # of calls to malloc/realloc 778 static julong alloc_bytes; // # of bytes allocated 779 static julong num_frees; // # of calls to free 780 static julong free_bytes; // # of bytes freed 781 #endif 782 783 // SocketInterface (ex HPI SocketInterface ) 784 static int socket(int domain, int type, int protocol); 785 static int socket_close(int fd); 786 static int recv(int fd, char* buf, size_t nBytes, uint flags); 787 static int send(int fd, char* buf, size_t nBytes, uint flags); 788 static int raw_send(int fd, char* buf, size_t nBytes, uint flags); 789 static int connect(int fd, struct sockaddr* him, socklen_t len); 790 static struct hostent* get_host_by_name(char* name); 791 792 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal) 793 static void initialize_jdk_signal_support(TRAPS); 794 static void signal_notify(int signal_number); 795 static void* signal(int signal_number, void* handler); 796 static void signal_raise(int signal_number); 797 static int signal_wait(); 798 static void* user_handler(); 799 static void terminate_signal_thread(); 800 static int sigexitnum_pd(); 801 802 // random number generation 803 static int random(); // return 32bit pseudorandom number 804 static void init_random(unsigned int initval); // initialize random sequence 805 806 // Structured OS Exception support 807 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread); 808 809 // On Posix compatible OS it will simply check core dump limits while on Windows 810 // it will check if dump file can be created. Check or prepare a core dump to be 811 // taken at a later point in the same thread in os::abort(). Use the caller 812 // provided buffer as a scratch buffer. The status message which will be written 813 // into the error log either is file location or a short error message, depending 814 // on the checking result. 815 static void check_dump_limit(char* buffer, size_t bufferSize); 816 817 // Get the default path to the core file 818 // Returns the length of the string 819 static int get_core_path(char* buffer, size_t bufferSize); 820 821 // JVMTI & JVM monitoring and management support 822 // The thread_cpu_time() and current_thread_cpu_time() are only 823 // supported if is_thread_cpu_time_supported() returns true. 824 // They are not supported on Solaris T1. 825 826 // Thread CPU Time - return the fast estimate on a platform 827 // On Solaris - call gethrvtime (fast) - user time only 828 // On Linux - fast clock_gettime where available - user+sys 829 // - otherwise: very slow /proc fs - user+sys 830 // On Windows - GetThreadTimes - user+sys 831 static jlong current_thread_cpu_time(); 832 static jlong thread_cpu_time(Thread* t); 833 834 // Thread CPU Time with user_sys_cpu_time parameter. 835 // 836 // If user_sys_cpu_time is true, user+sys time is returned. 837 // Otherwise, only user time is returned 838 static jlong current_thread_cpu_time(bool user_sys_cpu_time); 839 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time); 840 841 // Return a bunch of info about the timers. 842 // Note that the returned info for these two functions may be different 843 // on some platforms 844 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 845 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 846 847 static bool is_thread_cpu_time_supported(); 848 849 // System loadavg support. Returns -1 if load average cannot be obtained. 850 static int loadavg(double loadavg[], int nelem); 851 852 // Hook for os specific jvm options that we don't want to abort on seeing 853 static bool obsolete_option(const JavaVMOption *option); 854 855 // Amount beyond the callee frame size that we bang the stack. 856 static int extra_bang_size_in_bytes(); 857 858 static char** split_path(const char* path, int* n); 859 860 // Extensions 861 #include "runtime/os_ext.hpp" 862 863 public: 864 class CrashProtectionCallback : public StackObj { 865 public: 866 virtual void call() = 0; 867 }; 868 869 // Platform dependent stuff 870 #ifndef _WINDOWS 871 # include "os_posix.hpp" 872 #endif 873 #include OS_CPU_HEADER(os) 874 #include OS_HEADER(os) 875 876 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG 877 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached" 878 #endif 879 880 public: 881 #ifndef PLATFORM_PRINT_NATIVE_STACK 882 // No platform-specific code for printing the native stack. 883 static bool platform_print_native_stack(outputStream* st, const void* context, 884 char *buf, int buf_size) { 885 return false; 886 } 887 #endif 888 889 // debugging support (mostly used by debug.cpp but also fatal error handler) 890 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address 891 892 static bool dont_yield(); // when true, JVM_Yield() is nop 893 static void print_statistics(); 894 895 // Thread priority helpers (implemented in OS-specific part) 896 static OSReturn set_native_priority(Thread* thread, int native_prio); 897 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr); 898 static int java_to_os_priority[CriticalPriority + 1]; 899 // Hint to the underlying OS that a task switch would not be good. 900 // Void return because it's a hint and can fail. 901 static const char* native_thread_creation_failed_msg() { 902 return OS_NATIVE_THREAD_CREATION_FAILED_MSG; 903 } 904 905 // Used at creation if requested by the diagnostic flag PauseAtStartup. 906 // Causes the VM to wait until an external stimulus has been applied 907 // (for Unix, that stimulus is a signal, for Windows, an external 908 // ResumeThread call) 909 static void pause(); 910 911 // Builds a platform dependent Agent_OnLoad_<libname> function name 912 // which is used to find statically linked in agents. 913 static char* build_agent_function_name(const char *sym, const char *cname, 914 bool is_absolute_path); 915 916 class SuspendedThreadTaskContext { 917 public: 918 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {} 919 Thread* thread() const { return _thread; } 920 void* ucontext() const { return _ucontext; } 921 private: 922 Thread* _thread; 923 void* _ucontext; 924 }; 925 926 class SuspendedThreadTask { 927 public: 928 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {} 929 void run(); 930 bool is_done() { return _done; } 931 virtual void do_task(const SuspendedThreadTaskContext& context) = 0; 932 protected: 933 ~SuspendedThreadTask() {} 934 private: 935 void internal_do_task(); 936 Thread* _thread; 937 bool _done; 938 }; 939 940 #ifndef _WINDOWS 941 // Suspend/resume support 942 // Protocol: 943 // 944 // a thread starts in SR_RUNNING 945 // 946 // SR_RUNNING can go to 947 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it 948 // SR_SUSPEND_REQUEST can go to 949 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout) 950 // * SR_SUSPENDED if the stopped thread receives the signal and switches state 951 // SR_SUSPENDED can go to 952 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume 953 // SR_WAKEUP_REQUEST can go to 954 // * SR_RUNNING when the stopped thread receives the signal 955 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again) 956 class SuspendResume { 957 public: 958 enum State { 959 SR_RUNNING, 960 SR_SUSPEND_REQUEST, 961 SR_SUSPENDED, 962 SR_WAKEUP_REQUEST 963 }; 964 965 private: 966 volatile State _state; 967 968 private: 969 /* try to switch state from state "from" to state "to" 970 * returns the state set after the method is complete 971 */ 972 State switch_state(State from, State to); 973 974 public: 975 SuspendResume() : _state(SR_RUNNING) { } 976 977 State state() const { return _state; } 978 979 State request_suspend() { 980 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST); 981 } 982 983 State cancel_suspend() { 984 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING); 985 } 986 987 State suspended() { 988 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED); 989 } 990 991 State request_wakeup() { 992 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST); 993 } 994 995 State running() { 996 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING); 997 } 998 999 bool is_running() const { 1000 return _state == SR_RUNNING; 1001 } 1002 1003 bool is_suspend_request() const { 1004 return _state == SR_SUSPEND_REQUEST; 1005 } 1006 1007 bool is_suspended() const { 1008 return _state == SR_SUSPENDED; 1009 } 1010 }; 1011 #endif // !WINDOWS 1012 1013 1014 protected: 1015 static volatile unsigned int _rand_seed; // seed for random number generator 1016 static int _processor_count; // number of processors 1017 static int _initial_active_processor_count; // number of active processors during initialization. 1018 1019 static char* format_boot_path(const char* format_string, 1020 const char* home, 1021 int home_len, 1022 char fileSep, 1023 char pathSep); 1024 static bool set_boot_path(char fileSep, char pathSep); 1025 1026 }; 1027 1028 #ifndef _WINDOWS 1029 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {}; 1030 #endif // !_WINDOWS 1031 1032 // Note that "PAUSE" is almost always used with synchronization 1033 // so arguably we should provide Atomic::SpinPause() instead 1034 // of the global SpinPause() with C linkage. 1035 // It'd also be eligible for inlining on many platforms. 1036 1037 extern "C" int SpinPause(); 1038 1039 #endif // SHARE_VM_RUNTIME_OS_HPP