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 // Return a lower bound for page sizes. Also works before os::init completed. 307 static size_t min_page_size() { return 4 * K; } 308 309 // Methods for tracing page sizes returned by the above method. 310 // The region_{min,max}_size parameters should be the values 311 // passed to page_size_for_region() and page_size should be the result of that 312 // call. The (optional) base and size parameters should come from the 313 // ReservedSpace base() and size() methods. 314 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count); 315 static void trace_page_sizes(const char* str, 316 const size_t region_min_size, 317 const size_t region_max_size, 318 const size_t page_size, 319 const char* base, 320 const size_t size); 321 static void trace_page_sizes_for_requested_size(const char* str, 322 const size_t requested_size, 323 const size_t page_size, 324 const size_t alignment, 325 const char* base, 326 const size_t size); 327 328 static int vm_allocation_granularity(); 329 static char* reserve_memory(size_t bytes, char* addr = 0, 330 size_t alignment_hint = 0, int file_desc = -1); 331 static char* reserve_memory(size_t bytes, char* addr, 332 size_t alignment_hint, MEMFLAGS flags); 333 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1); 334 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1); 335 static void split_reserved_memory(char *base, size_t size, 336 size_t split, bool realloc); 337 static bool commit_memory(char* addr, size_t bytes, bool executable); 338 static bool commit_memory(char* addr, size_t size, size_t alignment_hint, 339 bool executable); 340 // Same as commit_memory() that either succeeds or calls 341 // vm_exit_out_of_memory() with the specified mesg. 342 static void commit_memory_or_exit(char* addr, size_t bytes, 343 bool executable, const char* mesg); 344 static void commit_memory_or_exit(char* addr, size_t size, 345 size_t alignment_hint, 346 bool executable, const char* mesg); 347 static bool uncommit_memory(char* addr, size_t bytes); 348 static bool release_memory(char* addr, size_t bytes); 349 350 // Touch memory pages that cover the memory range from start to end (exclusive) 351 // to make the OS back the memory range with actual memory. 352 // Current implementation may not touch the last page if unaligned addresses 353 // are passed. 354 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size()); 355 356 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX }; 357 static bool protect_memory(char* addr, size_t bytes, ProtType prot, 358 bool is_committed = true); 359 360 static bool guard_memory(char* addr, size_t bytes); 361 static bool unguard_memory(char* addr, size_t bytes); 362 static bool create_stack_guard_pages(char* addr, size_t bytes); 363 static bool pd_create_stack_guard_pages(char* addr, size_t bytes); 364 static bool remove_stack_guard_pages(char* addr, size_t bytes); 365 // Helper function to create a new file with template jvmheap.XXXXXX. 366 // Returns a valid fd on success or else returns -1 367 static int create_file_for_heap(const char* dir); 368 // Map memory to the file referred by fd. This function is slightly different from map_memory() 369 // and is added to be used for implementation of -XX:AllocateHeapAt 370 static char* map_memory_to_file(char* base, size_t size, int fd); 371 // Replace existing reserved memory with file mapping 372 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd); 373 374 static char* map_memory(int fd, const char* file_name, size_t file_offset, 375 char *addr, size_t bytes, bool read_only = false, 376 bool allow_exec = false); 377 static char* remap_memory(int fd, const char* file_name, size_t file_offset, 378 char *addr, size_t bytes, bool read_only, 379 bool allow_exec); 380 static bool unmap_memory(char *addr, size_t bytes); 381 static void free_memory(char *addr, size_t bytes, size_t alignment_hint); 382 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint); 383 384 // NUMA-specific interface 385 static bool numa_has_static_binding(); 386 static bool numa_has_group_homing(); 387 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint); 388 static void numa_make_global(char *addr, size_t bytes); 389 static size_t numa_get_groups_num(); 390 static size_t numa_get_leaf_groups(int *ids, size_t size); 391 static bool numa_topology_changed(); 392 static int numa_get_group_id(); 393 394 // Page manipulation 395 struct page_info { 396 size_t size; 397 int lgrp_id; 398 }; 399 static bool get_page_info(char *start, page_info* info); 400 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found); 401 402 static char* non_memory_address_word(); 403 // reserve, commit and pin the entire memory region 404 static char* reserve_memory_special(size_t size, size_t alignment, 405 char* addr, bool executable); 406 static bool release_memory_special(char* addr, size_t bytes); 407 static void large_page_init(); 408 static size_t large_page_size(); 409 static bool can_commit_large_page_memory(); 410 static bool can_execute_large_page_memory(); 411 412 // OS interface to polling page 413 static address get_polling_page() { return _polling_page; } 414 static void set_polling_page(address page) { _polling_page = page; } 415 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); } 416 static void make_polling_page_unreadable(); 417 static void make_polling_page_readable(); 418 419 // Check if pointer points to readable memory (by 4-byte read access) 420 static bool is_readable_pointer(const void* p); 421 static bool is_readable_range(const void* from, const void* to); 422 423 // Routines used to serialize the thread state without using membars 424 static void serialize_thread_states(); 425 426 // Since we write to the serialize page from every thread, we 427 // want stores to be on unique cache lines whenever possible 428 // in order to minimize CPU cross talk. We pre-compute the 429 // amount to shift the thread* to make this offset unique to 430 // each thread. 431 static int get_serialize_page_shift_count() { 432 return SerializePageShiftCount; 433 } 434 435 static void set_serialize_page_mask(uintptr_t mask) { 436 _serialize_page_mask = mask; 437 } 438 439 static unsigned int get_serialize_page_mask() { 440 return _serialize_page_mask; 441 } 442 443 static void set_memory_serialize_page(address page); 444 445 static address get_memory_serialize_page() { 446 return (address)_mem_serialize_page; 447 } 448 449 static inline void write_memory_serialize_page(JavaThread *thread) { 450 uintptr_t page_offset = ((uintptr_t)thread >> 451 get_serialize_page_shift_count()) & 452 get_serialize_page_mask(); 453 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1; 454 } 455 456 static bool is_memory_serialize_page(JavaThread *thread, address addr) { 457 if (UseMembar) return false; 458 // Previously this function calculated the exact address of this 459 // thread's serialize page, and checked if the faulting address 460 // was equal. However, some platforms mask off faulting addresses 461 // to the page size, so now we just check that the address is 462 // within the page. This makes the thread argument unnecessary, 463 // but we retain the NULL check to preserve existing behavior. 464 if (thread == NULL) return false; 465 address page = (address) _mem_serialize_page; 466 return addr >= page && addr < (page + os::vm_page_size()); 467 } 468 469 static void block_on_serialize_page_trap(); 470 471 // threads 472 473 enum ThreadType { 474 vm_thread, 475 cgc_thread, // Concurrent GC thread 476 pgc_thread, // Parallel GC thread 477 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads. 478 compiler_thread, 479 watcher_thread, 480 os_thread 481 }; 482 483 static bool create_thread(Thread* thread, 484 ThreadType thr_type, 485 size_t req_stack_size = 0); 486 487 // The "main thread", also known as "starting thread", is the thread 488 // that loads/creates the JVM via JNI_CreateJavaVM. 489 static bool create_main_thread(JavaThread* thread); 490 491 // The primordial thread is the initial process thread. The java 492 // launcher never uses the primordial thread as the main thread, but 493 // applications that host the JVM directly may do so. Some platforms 494 // need special-case handling of the primordial thread if it attaches 495 // to the VM. 496 static bool is_primordial_thread(void) 497 #if defined(_WINDOWS) || defined(BSD) 498 // No way to identify the primordial thread. 499 { return false; } 500 #else 501 ; 502 #endif 503 504 static bool create_attached_thread(JavaThread* thread); 505 static void pd_start_thread(Thread* thread); 506 static void start_thread(Thread* thread); 507 508 static void free_thread(OSThread* osthread); 509 510 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit 511 static intx current_thread_id(); 512 static int current_process_id(); 513 static int sleep(Thread* thread, jlong ms, bool interruptable); 514 // Short standalone OS sleep suitable for slow path spin loop. 515 // Ignores Thread.interrupt() (so keep it short). 516 // ms = 0, will sleep for the least amount of time allowed by the OS. 517 static void naked_short_sleep(jlong ms); 518 static void infinite_sleep(); // never returns, use with CAUTION 519 static void naked_yield () ; 520 static OSReturn set_priority(Thread* thread, ThreadPriority priority); 521 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority); 522 523 static void interrupt(Thread* thread); 524 static bool is_interrupted(Thread* thread, bool clear_interrupted); 525 526 static int pd_self_suspend_thread(Thread* thread); 527 528 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp); 529 static frame fetch_frame_from_context(const void* ucVoid); 530 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid); 531 532 static void breakpoint(); 533 static bool start_debugging(char *buf, int buflen); 534 535 static address current_stack_pointer(); 536 static address current_stack_base(); 537 static size_t current_stack_size(); 538 539 static void verify_stack_alignment() PRODUCT_RETURN; 540 541 static bool message_box(const char* title, const char* message); 542 static char* do_you_want_to_debug(const char* message); 543 544 // run cmd in a separate process and return its exit code; or -1 on failures 545 static int fork_and_exec(char *cmd, bool use_vfork_if_available = false); 546 547 // Call ::exit() on all platforms but Windows 548 static void exit(int num); 549 550 // Terminate the VM, but don't exit the process 551 static void shutdown(); 552 553 // Terminate with an error. Default is to generate a core file on platforms 554 // that support such things. This calls shutdown() and then aborts. 555 static void abort(bool dump_core, void *siginfo, const void *context); 556 static void abort(bool dump_core = true); 557 558 // Die immediately, no exit hook, no abort hook, no cleanup. 559 static void die(); 560 561 // File i/o operations 562 static const int default_file_open_flags(); 563 static int open(const char *path, int oflag, int mode); 564 static FILE* open(int fd, const char* mode); 565 static FILE* fopen(const char* path, const char* mode); 566 static int close(int fd); 567 static jlong lseek(int fd, jlong offset, int whence); 568 // This function, on Windows, canonicalizes a given path (see os_windows.cpp for details). 569 // On Posix, this function is a noop: it does not change anything and just returns 570 // the input pointer. 571 static char* native_path(char *path); 572 static int ftruncate(int fd, jlong length); 573 static int fsync(int fd); 574 static int available(int fd, jlong *bytes); 575 static int get_fileno(FILE* fp); 576 static void flockfile(FILE* fp); 577 static void funlockfile(FILE* fp); 578 579 static int compare_file_modified_times(const char* file1, const char* file2); 580 581 //File i/o operations 582 583 static size_t read(int fd, void *buf, unsigned int nBytes); 584 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset); 585 static size_t restartable_read(int fd, void *buf, unsigned int nBytes); 586 static size_t write(int fd, const void *buf, unsigned int nBytes); 587 588 // Reading directories. 589 static DIR* opendir(const char* dirname); 590 static struct dirent* readdir(DIR* dirp); 591 static int closedir(DIR* dirp); 592 593 // Dynamic library extension 594 static const char* dll_file_extension(); 595 596 static const char* get_temp_directory(); 597 static const char* get_current_directory(char *buf, size_t buflen); 598 599 // Builds the platform-specific name of a library. 600 // Returns false if the buffer is too small. 601 static bool dll_build_name(char* buffer, size_t size, 602 const char* fname); 603 604 // Builds a platform-specific full library path given an ld path and 605 // unadorned library name. Returns true if the buffer contains a full 606 // path to an existing file, false otherwise. If pathname is empty, 607 // uses the path to the current directory. 608 static bool dll_locate_lib(char* buffer, size_t size, 609 const char* pathname, const char* fname); 610 611 // Symbol lookup, find nearest function name; basically it implements 612 // dladdr() for all platforms. Name of the nearest function is copied 613 // to buf. Distance from its base address is optionally returned as offset. 614 // If function name is not found, buf[0] is set to '\0' and offset is 615 // set to -1 (if offset is non-NULL). 616 static bool dll_address_to_function_name(address addr, char* buf, 617 int buflen, int* offset, 618 bool demangle = true); 619 620 // Locate DLL/DSO. On success, full path of the library is copied to 621 // buf, and offset is optionally set to be the distance between addr 622 // and the library's base address. On failure, buf[0] is set to '\0' 623 // and offset is set to -1 (if offset is non-NULL). 624 static bool dll_address_to_library_name(address addr, char* buf, 625 int buflen, int* offset); 626 627 // Find out whether the pc is in the static code for jvm.dll/libjvm.so. 628 static bool address_is_in_vm(address addr); 629 630 // Loads .dll/.so and 631 // in case of error it checks if .dll/.so was built for the 632 // same architecture as HotSpot is running on 633 static void* dll_load(const char *name, char *ebuf, int ebuflen); 634 635 // lookup symbol in a shared library 636 static void* dll_lookup(void* handle, const char* name); 637 638 // Unload library 639 static void dll_unload(void *lib); 640 641 // Callback for loaded module information 642 // Input parameters: 643 // char* module_file_name, 644 // address module_base_addr, 645 // address module_top_addr, 646 // void* param 647 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *); 648 649 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param); 650 651 // Return the handle of this process 652 static void* get_default_process_handle(); 653 654 // Check for static linked agent library 655 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 656 size_t syms_len); 657 658 // Find agent entry point 659 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib, 660 const char *syms[], size_t syms_len); 661 662 // Provide C99 compliant versions of these functions, since some versions 663 // of some platforms don't. 664 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0); 665 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4); 666 667 // Get host name in buffer provided 668 static bool get_host_name(char* buf, size_t buflen); 669 670 // Print out system information; they are called by fatal error handler. 671 // Output format may be different on different platforms. 672 static void print_os_info(outputStream* st); 673 static void print_os_info_brief(outputStream* st); 674 static void print_cpu_info(outputStream* st, char* buf, size_t buflen); 675 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen); 676 static void print_summary_info(outputStream* st, char* buf, size_t buflen); 677 static void print_memory_info(outputStream* st); 678 static void print_dll_info(outputStream* st); 679 static void print_environment_variables(outputStream* st, const char** env_list); 680 static void print_context(outputStream* st, const void* context); 681 static void print_register_info(outputStream* st, const void* context); 682 static void print_siginfo(outputStream* st, const void* siginfo); 683 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen); 684 static void print_date_and_time(outputStream* st, char* buf, size_t buflen); 685 686 static void print_location(outputStream* st, intptr_t x, bool verbose = false); 687 static size_t lasterror(char *buf, size_t len); 688 static int get_last_error(); 689 690 // Replacement for strerror(). 691 // Will return the english description of the error (e.g. "File not found", as 692 // suggested in the POSIX standard. 693 // Will return "Unknown error" for an unknown errno value. 694 // Will not attempt to localize the returned string. 695 // Will always return a valid string which is a static constant. 696 // Will not change the value of errno. 697 static const char* strerror(int e); 698 699 // Will return the literalized version of the given errno (e.g. "EINVAL" 700 // for EINVAL). 701 // Will return "Unknown error" for an unknown errno value. 702 // Will always return a valid string which is a static constant. 703 // Will not change the value of errno. 704 static const char* errno_name(int e); 705 706 // Determines whether the calling process is being debugged by a user-mode debugger. 707 static bool is_debugger_attached(); 708 709 // wait for a key press if PauseAtExit is set 710 static void wait_for_keypress_at_exit(void); 711 712 // The following two functions are used by fatal error handler to trace 713 // native (C) frames. They are not part of frame.hpp/frame.cpp because 714 // frame.hpp/cpp assume thread is JavaThread, and also because different 715 // OS/compiler may have different convention or provide different API to 716 // walk C frames. 717 // 718 // We don't attempt to become a debugger, so we only follow frames if that 719 // does not require a lookup in the unwind table, which is part of the binary 720 // file but may be unsafe to read after a fatal error. So on x86, we can 721 // only walk stack if %ebp is used as frame pointer; on ia64, it's not 722 // possible to walk C stack without having the unwind table. 723 static bool is_first_C_frame(frame *fr); 724 static frame get_sender_for_C_frame(frame *fr); 725 726 // return current frame. pc() and sp() are set to NULL on failure. 727 static frame current_frame(); 728 729 static void print_hex_dump(outputStream* st, address start, address end, int unitsize); 730 731 // returns a string to describe the exception/signal; 732 // returns NULL if exception_code is not an OS exception/signal. 733 static const char* exception_name(int exception_code, char* buf, size_t buflen); 734 735 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV). 736 static int get_signal_number(const char* signal_name); 737 738 // Returns native Java library, loads if necessary 739 static void* native_java_library(); 740 741 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler) 742 static void jvm_path(char *buf, jint buflen); 743 744 // JNI names 745 static void print_jni_name_prefix_on(outputStream* st, int args_size); 746 static void print_jni_name_suffix_on(outputStream* st, int args_size); 747 748 // Init os specific system properties values 749 static void init_system_properties_values(); 750 751 // IO operations, non-JVM_ version. 752 static int stat(const char* path, struct stat* sbuf); 753 static bool dir_is_empty(const char* path); 754 755 // IO operations on binary files 756 static int create_binary_file(const char* path, bool rewrite_existing); 757 static jlong current_file_offset(int fd); 758 static jlong seek_to_file_offset(int fd, jlong offset); 759 760 // Retrieve native stack frames. 761 // Parameter: 762 // stack: an array to storage stack pointers. 763 // frames: size of above array. 764 // toSkip: number of stack frames to skip at the beginning. 765 // Return: number of stack frames captured. 766 static int get_native_stack(address* stack, int size, int toSkip = 0); 767 768 // General allocation (must be MT-safe) 769 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack); 770 static void* malloc (size_t size, MEMFLAGS flags); 771 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack); 772 static void* realloc (void *memblock, size_t size, MEMFLAGS flag); 773 774 static void free (void *memblock); 775 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup 776 // Like strdup, but exit VM when strdup() returns NULL 777 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal); 778 779 #ifndef PRODUCT 780 static julong num_mallocs; // # of calls to malloc/realloc 781 static julong alloc_bytes; // # of bytes allocated 782 static julong num_frees; // # of calls to free 783 static julong free_bytes; // # of bytes freed 784 #endif 785 786 // SocketInterface (ex HPI SocketInterface ) 787 static int socket(int domain, int type, int protocol); 788 static int socket_close(int fd); 789 static int recv(int fd, char* buf, size_t nBytes, uint flags); 790 static int send(int fd, char* buf, size_t nBytes, uint flags); 791 static int raw_send(int fd, char* buf, size_t nBytes, uint flags); 792 static int connect(int fd, struct sockaddr* him, socklen_t len); 793 static struct hostent* get_host_by_name(char* name); 794 795 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal) 796 static void initialize_jdk_signal_support(TRAPS); 797 static void signal_notify(int signal_number); 798 static void* signal(int signal_number, void* handler); 799 static void signal_raise(int signal_number); 800 static int signal_wait(); 801 static void* user_handler(); 802 static void terminate_signal_thread(); 803 static int sigexitnum_pd(); 804 805 // random number generation 806 static int random(); // return 32bit pseudorandom number 807 static void init_random(unsigned int initval); // initialize random sequence 808 809 // Structured OS Exception support 810 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread); 811 812 // On Posix compatible OS it will simply check core dump limits while on Windows 813 // it will check if dump file can be created. Check or prepare a core dump to be 814 // taken at a later point in the same thread in os::abort(). Use the caller 815 // provided buffer as a scratch buffer. The status message which will be written 816 // into the error log either is file location or a short error message, depending 817 // on the checking result. 818 static void check_dump_limit(char* buffer, size_t bufferSize); 819 820 // Get the default path to the core file 821 // Returns the length of the string 822 static int get_core_path(char* buffer, size_t bufferSize); 823 824 // JVMTI & JVM monitoring and management support 825 // The thread_cpu_time() and current_thread_cpu_time() are only 826 // supported if is_thread_cpu_time_supported() returns true. 827 // They are not supported on Solaris T1. 828 829 // Thread CPU Time - return the fast estimate on a platform 830 // On Solaris - call gethrvtime (fast) - user time only 831 // On Linux - fast clock_gettime where available - user+sys 832 // - otherwise: very slow /proc fs - user+sys 833 // On Windows - GetThreadTimes - user+sys 834 static jlong current_thread_cpu_time(); 835 static jlong thread_cpu_time(Thread* t); 836 837 // Thread CPU Time with user_sys_cpu_time parameter. 838 // 839 // If user_sys_cpu_time is true, user+sys time is returned. 840 // Otherwise, only user time is returned 841 static jlong current_thread_cpu_time(bool user_sys_cpu_time); 842 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time); 843 844 // Return a bunch of info about the timers. 845 // Note that the returned info for these two functions may be different 846 // on some platforms 847 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 848 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 849 850 static bool is_thread_cpu_time_supported(); 851 852 // System loadavg support. Returns -1 if load average cannot be obtained. 853 static int loadavg(double loadavg[], int nelem); 854 855 // Hook for os specific jvm options that we don't want to abort on seeing 856 static bool obsolete_option(const JavaVMOption *option); 857 858 // Amount beyond the callee frame size that we bang the stack. 859 static int extra_bang_size_in_bytes(); 860 861 static char** split_path(const char* path, int* n); 862 863 // Extensions 864 #include "runtime/os_ext.hpp" 865 866 public: 867 class CrashProtectionCallback : public StackObj { 868 public: 869 virtual void call() = 0; 870 }; 871 872 // Platform dependent stuff 873 #ifndef _WINDOWS 874 # include "os_posix.hpp" 875 #endif 876 #include OS_CPU_HEADER(os) 877 #include OS_HEADER(os) 878 879 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG 880 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached" 881 #endif 882 883 public: 884 #ifndef PLATFORM_PRINT_NATIVE_STACK 885 // No platform-specific code for printing the native stack. 886 static bool platform_print_native_stack(outputStream* st, const void* context, 887 char *buf, int buf_size) { 888 return false; 889 } 890 #endif 891 892 // debugging support (mostly used by debug.cpp but also fatal error handler) 893 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address 894 895 static bool dont_yield(); // when true, JVM_Yield() is nop 896 static void print_statistics(); 897 898 // Thread priority helpers (implemented in OS-specific part) 899 static OSReturn set_native_priority(Thread* thread, int native_prio); 900 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr); 901 static int java_to_os_priority[CriticalPriority + 1]; 902 // Hint to the underlying OS that a task switch would not be good. 903 // Void return because it's a hint and can fail. 904 static const char* native_thread_creation_failed_msg() { 905 return OS_NATIVE_THREAD_CREATION_FAILED_MSG; 906 } 907 908 // Used at creation if requested by the diagnostic flag PauseAtStartup. 909 // Causes the VM to wait until an external stimulus has been applied 910 // (for Unix, that stimulus is a signal, for Windows, an external 911 // ResumeThread call) 912 static void pause(); 913 914 // Builds a platform dependent Agent_OnLoad_<libname> function name 915 // which is used to find statically linked in agents. 916 static char* build_agent_function_name(const char *sym, const char *cname, 917 bool is_absolute_path); 918 919 class SuspendedThreadTaskContext { 920 public: 921 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {} 922 Thread* thread() const { return _thread; } 923 void* ucontext() const { return _ucontext; } 924 private: 925 Thread* _thread; 926 void* _ucontext; 927 }; 928 929 class SuspendedThreadTask { 930 public: 931 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {} 932 void run(); 933 bool is_done() { return _done; } 934 virtual void do_task(const SuspendedThreadTaskContext& context) = 0; 935 protected: 936 ~SuspendedThreadTask() {} 937 private: 938 void internal_do_task(); 939 Thread* _thread; 940 bool _done; 941 }; 942 943 #ifndef _WINDOWS 944 // Suspend/resume support 945 // Protocol: 946 // 947 // a thread starts in SR_RUNNING 948 // 949 // SR_RUNNING can go to 950 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it 951 // SR_SUSPEND_REQUEST can go to 952 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout) 953 // * SR_SUSPENDED if the stopped thread receives the signal and switches state 954 // SR_SUSPENDED can go to 955 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume 956 // SR_WAKEUP_REQUEST can go to 957 // * SR_RUNNING when the stopped thread receives the signal 958 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again) 959 class SuspendResume { 960 public: 961 enum State { 962 SR_RUNNING, 963 SR_SUSPEND_REQUEST, 964 SR_SUSPENDED, 965 SR_WAKEUP_REQUEST 966 }; 967 968 private: 969 volatile State _state; 970 971 private: 972 /* try to switch state from state "from" to state "to" 973 * returns the state set after the method is complete 974 */ 975 State switch_state(State from, State to); 976 977 public: 978 SuspendResume() : _state(SR_RUNNING) { } 979 980 State state() const { return _state; } 981 982 State request_suspend() { 983 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST); 984 } 985 986 State cancel_suspend() { 987 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING); 988 } 989 990 State suspended() { 991 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED); 992 } 993 994 State request_wakeup() { 995 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST); 996 } 997 998 State running() { 999 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING); 1000 } 1001 1002 bool is_running() const { 1003 return _state == SR_RUNNING; 1004 } 1005 1006 bool is_suspend_request() const { 1007 return _state == SR_SUSPEND_REQUEST; 1008 } 1009 1010 bool is_suspended() const { 1011 return _state == SR_SUSPENDED; 1012 } 1013 }; 1014 #endif // !WINDOWS 1015 1016 1017 protected: 1018 static volatile unsigned int _rand_seed; // seed for random number generator 1019 static int _processor_count; // number of processors 1020 static int _initial_active_processor_count; // number of active processors during initialization. 1021 1022 static char* format_boot_path(const char* format_string, 1023 const char* home, 1024 int home_len, 1025 char fileSep, 1026 char pathSep); 1027 static bool set_boot_path(char fileSep, char pathSep); 1028 1029 }; 1030 1031 #ifndef _WINDOWS 1032 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {}; 1033 #endif // !_WINDOWS 1034 1035 // Note that "PAUSE" is almost always used with synchronization 1036 // so arguably we should provide Atomic::SpinPause() instead 1037 // of the global SpinPause() with C linkage. 1038 // It'd also be eligible for inlining on many platforms. 1039 1040 extern "C" int SpinPause(); 1041 1042 #endif // SHARE_VM_RUNTIME_OS_HPP