1 /* 2 * Copyright (c) 1997, 2019, 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_RUNTIME_OS_HPP 26 #define SHARE_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 NativeCallStack; 55 class methodHandle; 56 class OSThread; 57 class Mutex; 58 59 template<class E> class GrowableArray; 60 61 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose 62 63 // Platform-independent error return values from OS functions 64 enum OSReturn { 65 OS_OK = 0, // Operation was successful 66 OS_ERR = -1, // Operation failed 67 OS_INTRPT = -2, // Operation was interrupted 68 OS_TIMEOUT = -3, // Operation timed out 69 OS_NOMEM = -5, // Operation failed for lack of memory 70 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource 71 }; 72 73 enum ThreadPriority { // JLS 20.20.1-3 74 NoPriority = -1, // Initial non-priority value 75 MinPriority = 1, // Minimum priority 76 NormPriority = 5, // Normal (non-daemon) priority 77 NearMaxPriority = 9, // High priority, used for VMThread 78 MaxPriority = 10, // Highest priority, used for WatcherThread 79 // ensures that VMThread doesn't starve profiler 80 CriticalPriority = 11 // Critical thread priority 81 }; 82 83 // Executable parameter flag for os::commit_memory() and 84 // os::commit_memory_or_exit(). 85 const bool ExecMem = true; 86 87 // Typedef for structured exception handling support 88 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread); 89 90 class MallocTracker; 91 92 class os: AllStatic { 93 friend class VMStructs; 94 friend class JVMCIVMStructs; 95 friend class MallocTracker; 96 97 #ifdef ASSERT 98 private: 99 static bool _mutex_init_done; 100 public: 101 static void set_mutex_init_done() { _mutex_init_done = true; } 102 static bool mutex_init_done() { return _mutex_init_done; } 103 #endif 104 105 public: 106 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel) 107 108 private: 109 static OSThread* _starting_thread; 110 static address _polling_page; 111 public: 112 static size_t _page_sizes[page_sizes_max]; 113 114 private: 115 static void init_page_sizes(size_t default_page_size) { 116 _page_sizes[0] = default_page_size; 117 _page_sizes[1] = 0; // sentinel 118 } 119 120 static char* pd_reserve_memory(size_t bytes, char* addr = 0, 121 size_t alignment_hint = 0); 122 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr); 123 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc); 124 static void pd_split_reserved_memory(char *base, size_t size, 125 size_t split, bool realloc); 126 static bool pd_commit_memory(char* addr, size_t bytes, bool executable); 127 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 128 bool executable); 129 // Same as pd_commit_memory() that either succeeds or calls 130 // vm_exit_out_of_memory() with the specified mesg. 131 static void pd_commit_memory_or_exit(char* addr, size_t bytes, 132 bool executable, const char* mesg); 133 static void pd_commit_memory_or_exit(char* addr, size_t size, 134 size_t alignment_hint, 135 bool executable, const char* mesg); 136 static bool pd_uncommit_memory(char* addr, size_t bytes); 137 static bool pd_release_memory(char* addr, size_t bytes); 138 139 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset, 140 char *addr, size_t bytes, bool read_only = false, 141 bool allow_exec = false); 142 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset, 143 char *addr, size_t bytes, bool read_only, 144 bool allow_exec); 145 static bool pd_unmap_memory(char *addr, size_t bytes); 146 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint); 147 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint); 148 149 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned); 150 151 // Get summary strings for system information in buffer provided 152 static void get_summary_cpu_info(char* buf, size_t buflen); 153 static void get_summary_os_info(char* buf, size_t buflen); 154 155 static void initialize_initial_active_processor_count(); 156 157 LINUX_ONLY(static void pd_init_container_support();) 158 159 public: 160 static void init(void); // Called before command line parsing 161 162 static void init_container_support() { // Called during command line parsing. 163 LINUX_ONLY(pd_init_container_support();) 164 } 165 166 static void init_before_ergo(void); // Called after command line parsing 167 // before VM ergonomics processing. 168 static jint init_2(void); // Called after command line parsing 169 // and VM ergonomics processing 170 171 // unset environment variable 172 static bool unsetenv(const char* name); 173 174 static bool have_special_privileges(); 175 176 static jlong javaTimeMillis(); 177 static jlong javaTimeNanos(); 178 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr); 179 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos); 180 static void run_periodic_checks(); 181 static bool supports_monotonic_clock(); 182 183 // Returns the elapsed time in seconds since the vm started. 184 static double elapsedTime(); 185 186 // Returns real time in seconds since an arbitrary point 187 // in the past. 188 static bool getTimesSecs(double* process_real_time, 189 double* process_user_time, 190 double* process_system_time); 191 192 // Interface to the performance counter 193 static jlong elapsed_counter(); 194 static jlong elapsed_frequency(); 195 196 // The "virtual time" of a thread is the amount of time a thread has 197 // actually run. The first function indicates whether the OS supports 198 // this functionality for the current thread, and if so: 199 // * the second enables vtime tracking (if that is required). 200 // * the third tells whether vtime is enabled. 201 // * the fourth returns the elapsed virtual time for the current 202 // thread. 203 static bool supports_vtime(); 204 static bool enable_vtime(); 205 static bool vtime_enabled(); 206 static double elapsedVTime(); 207 208 // Return current local time in a string (YYYY-MM-DD HH:MM:SS). 209 // It is MT safe, but not async-safe, as reading time zone 210 // information may require a lock on some platforms. 211 static char* local_time_string(char *buf, size_t buflen); 212 static struct tm* localtime_pd (const time_t* clock, struct tm* res); 213 static struct tm* gmtime_pd (const time_t* clock, struct tm* res); 214 // Fill in buffer with current local time as an ISO-8601 string. 215 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz. 216 // Returns buffer, or NULL if it failed. 217 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false); 218 219 // Interface for detecting multiprocessor system 220 static inline bool is_MP() { 221 // During bootstrap if _processor_count is not yet initialized 222 // we claim to be MP as that is safest. If any platform has a 223 // stub generator that might be triggered in this phase and for 224 // which being declared MP when in fact not, is a problem - then 225 // the bootstrap routine for the stub generator needs to check 226 // the processor count directly and leave the bootstrap routine 227 // in place until called after initialization has ocurred. 228 return (_processor_count != 1); 229 } 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 // Return a lower bound for page sizes. Also works before os::init completed. 306 static size_t min_page_size() { return 4 * K; } 307 308 // Methods for tracing page sizes returned by the above method. 309 // The region_{min,max}_size parameters should be the values 310 // passed to page_size_for_region() and page_size should be the result of that 311 // call. The (optional) base and size parameters should come from the 312 // ReservedSpace base() and size() methods. 313 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count); 314 static void trace_page_sizes(const char* str, 315 const size_t region_min_size, 316 const size_t region_max_size, 317 const size_t page_size, 318 const char* base, 319 const size_t size); 320 static void trace_page_sizes_for_requested_size(const char* str, 321 const size_t requested_size, 322 const size_t page_size, 323 const size_t alignment, 324 const char* base, 325 const size_t size); 326 327 static int vm_allocation_granularity(); 328 static char* reserve_memory(size_t bytes, char* addr = 0, 329 size_t alignment_hint = 0, int file_desc = -1); 330 static char* reserve_memory(size_t bytes, char* addr, 331 size_t alignment_hint, MEMFLAGS flags); 332 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1); 333 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1); 334 static void split_reserved_memory(char *base, size_t size, 335 size_t split, bool realloc); 336 static bool commit_memory(char* addr, size_t bytes, bool executable); 337 static bool commit_memory(char* addr, size_t size, size_t alignment_hint, 338 bool executable); 339 // Same as commit_memory() that either succeeds or calls 340 // vm_exit_out_of_memory() with the specified mesg. 341 static void commit_memory_or_exit(char* addr, size_t bytes, 342 bool executable, const char* mesg); 343 static void commit_memory_or_exit(char* addr, size_t size, 344 size_t alignment_hint, 345 bool executable, const char* mesg); 346 static bool uncommit_memory(char* addr, size_t bytes); 347 static bool release_memory(char* addr, size_t bytes); 348 349 // Touch memory pages that cover the memory range from start to end (exclusive) 350 // to make the OS back the memory range with actual memory. 351 // Current implementation may not touch the last page if unaligned addresses 352 // are passed. 353 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size()); 354 355 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX }; 356 static bool protect_memory(char* addr, size_t bytes, ProtType prot, 357 bool is_committed = true); 358 359 static bool guard_memory(char* addr, size_t bytes); 360 static bool unguard_memory(char* addr, size_t bytes); 361 static bool create_stack_guard_pages(char* addr, size_t bytes); 362 static bool pd_create_stack_guard_pages(char* addr, size_t bytes); 363 static bool remove_stack_guard_pages(char* addr, size_t bytes); 364 // Helper function to create a new file with template jvmheap.XXXXXX. 365 // Returns a valid fd on success or else returns -1 366 static int create_file_for_heap(const char* dir); 367 // Map memory to the file referred by fd. This function is slightly different from map_memory() 368 // and is added to be used for implementation of -XX:AllocateHeapAt 369 static char* map_memory_to_file(char* base, size_t size, int fd); 370 // Replace existing reserved memory with file mapping 371 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd); 372 373 static char* map_memory(int fd, const char* file_name, size_t file_offset, 374 char *addr, size_t bytes, bool read_only = false, 375 bool allow_exec = false); 376 static char* remap_memory(int fd, const char* file_name, size_t file_offset, 377 char *addr, size_t bytes, bool read_only, 378 bool allow_exec); 379 static bool unmap_memory(char *addr, size_t bytes); 380 static void free_memory(char *addr, size_t bytes, size_t alignment_hint); 381 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint); 382 383 // NUMA-specific interface 384 static bool numa_has_static_binding(); 385 static bool numa_has_group_homing(); 386 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint); 387 static void numa_make_global(char *addr, size_t bytes); 388 static size_t numa_get_groups_num(); 389 static size_t numa_get_leaf_groups(int *ids, size_t size); 390 static bool numa_topology_changed(); 391 static int numa_get_group_id(); 392 393 // Page manipulation 394 struct page_info { 395 size_t size; 396 int lgrp_id; 397 }; 398 static bool get_page_info(char *start, page_info* info); 399 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found); 400 401 static char* non_memory_address_word(); 402 // reserve, commit and pin the entire memory region 403 static char* reserve_memory_special(size_t size, size_t alignment, 404 char* addr, bool executable); 405 static bool release_memory_special(char* addr, size_t bytes); 406 static void large_page_init(); 407 static size_t large_page_size(); 408 static bool can_commit_large_page_memory(); 409 static bool can_execute_large_page_memory(); 410 411 // OS interface to polling page 412 static address get_polling_page() { return _polling_page; } 413 static void set_polling_page(address page) { _polling_page = page; } 414 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); } 415 static void make_polling_page_unreadable(); 416 static void make_polling_page_readable(); 417 418 // Check if pointer points to readable memory (by 4-byte read access) 419 static bool is_readable_pointer(const void* p); 420 static bool is_readable_range(const void* from, const void* to); 421 422 // threads 423 424 enum ThreadType { 425 vm_thread, 426 cgc_thread, // Concurrent GC thread 427 pgc_thread, // Parallel GC thread 428 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads. 429 compiler_thread, 430 watcher_thread, 431 os_thread 432 }; 433 434 static bool create_thread(Thread* thread, 435 ThreadType thr_type, 436 size_t req_stack_size = 0); 437 438 // The "main thread", also known as "starting thread", is the thread 439 // that loads/creates the JVM via JNI_CreateJavaVM. 440 static bool create_main_thread(JavaThread* thread); 441 442 // The primordial thread is the initial process thread. The java 443 // launcher never uses the primordial thread as the main thread, but 444 // applications that host the JVM directly may do so. Some platforms 445 // need special-case handling of the primordial thread if it attaches 446 // to the VM. 447 static bool is_primordial_thread(void) 448 #if defined(_WINDOWS) || defined(BSD) 449 // No way to identify the primordial thread. 450 { return false; } 451 #else 452 ; 453 #endif 454 455 static bool create_attached_thread(JavaThread* thread); 456 static void pd_start_thread(Thread* thread); 457 static void start_thread(Thread* thread); 458 459 // Returns true if successful. 460 static bool signal_thread(Thread* thread, int sig, const char* reason); 461 462 static void free_thread(OSThread* osthread); 463 464 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit 465 static intx current_thread_id(); 466 static int current_process_id(); 467 468 // Short standalone OS sleep routines suitable for slow path spin loop. 469 // Ignores safepoints/suspension/Thread.interrupt() (so keep it short). 470 // ms/ns = 0, will sleep for the least amount of time allowed by the OS. 471 // Maximum sleep time is just under 1 second. 472 static void naked_short_sleep(jlong ms); 473 static void naked_short_nanosleep(jlong ns); 474 // Longer standalone OS sleep routine - a convenience wrapper around 475 // multiple calls to naked_short_sleep. Only for use by non-JavaThreads. 476 static void naked_sleep(jlong millis); 477 // Never returns, use with CAUTION 478 static void infinite_sleep(); 479 static void naked_yield () ; 480 static OSReturn set_priority(Thread* thread, ThreadPriority priority); 481 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority); 482 483 static int pd_self_suspend_thread(Thread* thread); 484 485 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp); 486 static frame fetch_frame_from_context(const void* ucVoid); 487 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid); 488 489 static void breakpoint(); 490 static bool start_debugging(char *buf, int buflen); 491 492 static address current_stack_pointer(); 493 static address current_stack_base(); 494 static size_t current_stack_size(); 495 496 static void verify_stack_alignment() PRODUCT_RETURN; 497 498 static bool message_box(const char* title, const char* message); 499 static char* do_you_want_to_debug(const char* message); 500 501 // run cmd in a separate process and return its exit code; or -1 on failures 502 static int fork_and_exec(char *cmd, bool use_vfork_if_available = false); 503 504 // Call ::exit() on all platforms but Windows 505 static void exit(int num); 506 507 // Terminate the VM, but don't exit the process 508 static void shutdown(); 509 510 // Terminate with an error. Default is to generate a core file on platforms 511 // that support such things. This calls shutdown() and then aborts. 512 static void abort(bool dump_core, void *siginfo, const void *context); 513 static void abort(bool dump_core = true); 514 515 // Die immediately, no exit hook, no abort hook, no cleanup. 516 // Dump a core file, if possible, for debugging. os::abort() is the 517 // preferred means to abort the VM on error. os::die() should only 518 // be called if something has gone badly wrong. CreateCoredumpOnCrash 519 // is intentionally not honored by this function. 520 static void die(); 521 522 // File i/o operations 523 static const int default_file_open_flags(); 524 static int open(const char *path, int oflag, int mode); 525 static FILE* open(int fd, const char* mode); 526 static FILE* fopen(const char* path, const char* mode); 527 static int close(int fd); 528 static jlong lseek(int fd, jlong offset, int whence); 529 // This function, on Windows, canonicalizes a given path (see os_windows.cpp for details). 530 // On Posix, this function is a noop: it does not change anything and just returns 531 // the input pointer. 532 static char* native_path(char *path); 533 static int ftruncate(int fd, jlong length); 534 static int fsync(int fd); 535 static int available(int fd, jlong *bytes); 536 static int get_fileno(FILE* fp); 537 static void flockfile(FILE* fp); 538 static void funlockfile(FILE* fp); 539 540 static int compare_file_modified_times(const char* file1, const char* file2); 541 542 static bool same_files(const char* file1, const char* file2); 543 544 //File i/o operations 545 546 static ssize_t read(int fd, void *buf, unsigned int nBytes); 547 static ssize_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset); 548 static size_t write(int fd, const void *buf, unsigned int nBytes); 549 550 // Reading directories. 551 static DIR* opendir(const char* dirname); 552 static struct dirent* readdir(DIR* dirp); 553 static int closedir(DIR* dirp); 554 555 // Dynamic library extension 556 static const char* dll_file_extension(); 557 558 static const char* get_temp_directory(); 559 static const char* get_current_directory(char *buf, size_t buflen); 560 561 // Builds the platform-specific name of a library. 562 // Returns false if the buffer is too small. 563 static bool dll_build_name(char* buffer, size_t size, 564 const char* fname); 565 566 // Builds a platform-specific full library path given an ld path and 567 // unadorned library name. Returns true if the buffer contains a full 568 // path to an existing file, false otherwise. If pathname is empty, 569 // uses the path to the current directory. 570 static bool dll_locate_lib(char* buffer, size_t size, 571 const char* pathname, const char* fname); 572 573 // Symbol lookup, find nearest function name; basically it implements 574 // dladdr() for all platforms. Name of the nearest function is copied 575 // to buf. Distance from its base address is optionally returned as offset. 576 // If function name is not found, buf[0] is set to '\0' and offset is 577 // set to -1 (if offset is non-NULL). 578 static bool dll_address_to_function_name(address addr, char* buf, 579 int buflen, int* offset, 580 bool demangle = true); 581 582 // Locate DLL/DSO. On success, full path of the library is copied to 583 // buf, and offset is optionally set to be the distance between addr 584 // and the library's base address. On failure, buf[0] is set to '\0' 585 // and offset is set to -1 (if offset is non-NULL). 586 static bool dll_address_to_library_name(address addr, char* buf, 587 int buflen, int* offset); 588 589 // Find out whether the pc is in the static code for jvm.dll/libjvm.so. 590 static bool address_is_in_vm(address addr); 591 592 // Loads .dll/.so and 593 // in case of error it checks if .dll/.so was built for the 594 // same architecture as HotSpot is running on 595 // in case of an error NULL is returned and an error message is stored in ebuf 596 static void* dll_load(const char *name, char *ebuf, int ebuflen); 597 598 // lookup symbol in a shared library 599 static void* dll_lookup(void* handle, const char* name); 600 601 // Unload library 602 static void dll_unload(void *lib); 603 604 // Callback for loaded module information 605 // Input parameters: 606 // char* module_file_name, 607 // address module_base_addr, 608 // address module_top_addr, 609 // void* param 610 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *); 611 612 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param); 613 614 // Return the handle of this process 615 static void* get_default_process_handle(); 616 617 // Check for static linked agent library 618 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 619 size_t syms_len); 620 621 // Find agent entry point 622 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib, 623 const char *syms[], size_t syms_len); 624 625 // Provide C99 compliant versions of these functions, since some versions 626 // of some platforms don't. 627 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0); 628 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4); 629 630 // Get host name in buffer provided 631 static bool get_host_name(char* buf, size_t buflen); 632 633 // Print out system information; they are called by fatal error handler. 634 // Output format may be different on different platforms. 635 static void print_os_info(outputStream* st); 636 static void print_os_info_brief(outputStream* st); 637 static void print_cpu_info(outputStream* st, char* buf, size_t buflen); 638 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen); 639 static void print_summary_info(outputStream* st, char* buf, size_t buflen); 640 static void print_memory_info(outputStream* st); 641 static void print_dll_info(outputStream* st); 642 static void print_environment_variables(outputStream* st, const char** env_list); 643 static void print_context(outputStream* st, const void* context); 644 static void print_register_info(outputStream* st, const void* context); 645 static bool signal_sent_by_kill(const void* siginfo); 646 static void print_siginfo(outputStream* st, const void* siginfo); 647 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen); 648 static void print_date_and_time(outputStream* st, char* buf, size_t buflen); 649 static void print_instructions(outputStream* st, address pc, int unitsize); 650 651 static void print_location(outputStream* st, intptr_t x, bool verbose = false); 652 static size_t lasterror(char *buf, size_t len); 653 static int get_last_error(); 654 655 // Replacement for strerror(). 656 // Will return the english description of the error (e.g. "File not found", as 657 // suggested in the POSIX standard. 658 // Will return "Unknown error" for an unknown errno value. 659 // Will not attempt to localize the returned string. 660 // Will always return a valid string which is a static constant. 661 // Will not change the value of errno. 662 static const char* strerror(int e); 663 664 // Will return the literalized version of the given errno (e.g. "EINVAL" 665 // for EINVAL). 666 // Will return "Unknown error" for an unknown errno value. 667 // Will always return a valid string which is a static constant. 668 // Will not change the value of errno. 669 static const char* errno_name(int e); 670 671 // Determines whether the calling process is being debugged by a user-mode debugger. 672 static bool is_debugger_attached(); 673 674 // wait for a key press if PauseAtExit is set 675 static void wait_for_keypress_at_exit(void); 676 677 // The following two functions are used by fatal error handler to trace 678 // native (C) frames. They are not part of frame.hpp/frame.cpp because 679 // frame.hpp/cpp assume thread is JavaThread, and also because different 680 // OS/compiler may have different convention or provide different API to 681 // walk C frames. 682 // 683 // We don't attempt to become a debugger, so we only follow frames if that 684 // does not require a lookup in the unwind table, which is part of the binary 685 // file but may be unsafe to read after a fatal error. So on x86, we can 686 // only walk stack if %ebp is used as frame pointer; on ia64, it's not 687 // possible to walk C stack without having the unwind table. 688 static bool is_first_C_frame(frame *fr); 689 static frame get_sender_for_C_frame(frame *fr); 690 691 // return current frame. pc() and sp() are set to NULL on failure. 692 static frame current_frame(); 693 694 static void print_hex_dump(outputStream* st, address start, address end, int unitsize); 695 696 // returns a string to describe the exception/signal; 697 // returns NULL if exception_code is not an OS exception/signal. 698 static const char* exception_name(int exception_code, char* buf, size_t buflen); 699 700 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV). 701 static int get_signal_number(const char* signal_name); 702 703 // Returns native Java library, loads if necessary 704 static void* native_java_library(); 705 706 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler) 707 static void jvm_path(char *buf, jint buflen); 708 709 // JNI names 710 static void print_jni_name_prefix_on(outputStream* st, int args_size); 711 static void print_jni_name_suffix_on(outputStream* st, int args_size); 712 713 // Init os specific system properties values 714 static void init_system_properties_values(); 715 716 // IO operations, non-JVM_ version. 717 static int stat(const char* path, struct stat* sbuf); 718 static bool dir_is_empty(const char* path); 719 720 // IO operations on binary files 721 static int create_binary_file(const char* path, bool rewrite_existing); 722 static jlong current_file_offset(int fd); 723 static jlong seek_to_file_offset(int fd, jlong offset); 724 725 // Retrieve native stack frames. 726 // Parameter: 727 // stack: an array to storage stack pointers. 728 // frames: size of above array. 729 // toSkip: number of stack frames to skip at the beginning. 730 // Return: number of stack frames captured. 731 static int get_native_stack(address* stack, int size, int toSkip = 0); 732 733 // General allocation (must be MT-safe) 734 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack); 735 static void* malloc (size_t size, MEMFLAGS flags); 736 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack); 737 static void* realloc (void *memblock, size_t size, MEMFLAGS flag); 738 739 // handles NULL pointers 740 static void free (void *memblock); 741 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup 742 // Like strdup, but exit VM when strdup() returns NULL 743 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal); 744 745 #ifndef PRODUCT 746 static julong num_mallocs; // # of calls to malloc/realloc 747 static julong alloc_bytes; // # of bytes allocated 748 static julong num_frees; // # of calls to free 749 static julong free_bytes; // # of bytes freed 750 #endif 751 752 // SocketInterface (ex HPI SocketInterface ) 753 static int socket(int domain, int type, int protocol); 754 static int socket_close(int fd); 755 static int recv(int fd, char* buf, size_t nBytes, uint flags); 756 static int send(int fd, char* buf, size_t nBytes, uint flags); 757 static int raw_send(int fd, char* buf, size_t nBytes, uint flags); 758 static int connect(int fd, struct sockaddr* him, socklen_t len); 759 static struct hostent* get_host_by_name(char* name); 760 761 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal) 762 static void initialize_jdk_signal_support(TRAPS); 763 static void signal_notify(int signal_number); 764 static void* signal(int signal_number, void* handler); 765 static void signal_raise(int signal_number); 766 static int signal_wait(); 767 static void* user_handler(); 768 static void terminate_signal_thread(); 769 static int sigexitnum_pd(); 770 771 // random number generation 772 static int random(); // return 32bit pseudorandom number 773 static void init_random(unsigned int initval); // initialize random sequence 774 775 // Structured OS Exception support 776 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread); 777 778 // On Posix compatible OS it will simply check core dump limits while on Windows 779 // it will check if dump file can be created. Check or prepare a core dump to be 780 // taken at a later point in the same thread in os::abort(). Use the caller 781 // provided buffer as a scratch buffer. The status message which will be written 782 // into the error log either is file location or a short error message, depending 783 // on the checking result. 784 static void check_dump_limit(char* buffer, size_t bufferSize); 785 786 // Get the default path to the core file 787 // Returns the length of the string 788 static int get_core_path(char* buffer, size_t bufferSize); 789 790 // JVMTI & JVM monitoring and management support 791 // The thread_cpu_time() and current_thread_cpu_time() are only 792 // supported if is_thread_cpu_time_supported() returns true. 793 // They are not supported on Solaris T1. 794 795 // Thread CPU Time - return the fast estimate on a platform 796 // On Solaris - call gethrvtime (fast) - user time only 797 // On Linux - fast clock_gettime where available - user+sys 798 // - otherwise: very slow /proc fs - user+sys 799 // On Windows - GetThreadTimes - user+sys 800 static jlong current_thread_cpu_time(); 801 static jlong thread_cpu_time(Thread* t); 802 803 // Thread CPU Time with user_sys_cpu_time parameter. 804 // 805 // If user_sys_cpu_time is true, user+sys time is returned. 806 // Otherwise, only user time is returned 807 static jlong current_thread_cpu_time(bool user_sys_cpu_time); 808 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time); 809 810 // Return a bunch of info about the timers. 811 // Note that the returned info for these two functions may be different 812 // on some platforms 813 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 814 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 815 816 static bool is_thread_cpu_time_supported(); 817 818 // System loadavg support. Returns -1 if load average cannot be obtained. 819 static int loadavg(double loadavg[], int nelem); 820 821 // Amount beyond the callee frame size that we bang the stack. 822 static int extra_bang_size_in_bytes(); 823 824 static char** split_path(const char* path, size_t* elements, size_t file_name_length); 825 826 // support for mapping non-volatile memory using MAP_SYNC 827 static bool supports_map_sync(); 828 829 public: 830 class CrashProtectionCallback : public StackObj { 831 public: 832 virtual void call() = 0; 833 }; 834 835 // Platform dependent stuff 836 #ifndef _WINDOWS 837 # include "os_posix.hpp" 838 #endif 839 #include OS_CPU_HEADER(os) 840 #include OS_HEADER(os) 841 842 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG 843 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached" 844 #endif 845 846 public: 847 #ifndef PLATFORM_PRINT_NATIVE_STACK 848 // No platform-specific code for printing the native stack. 849 static bool platform_print_native_stack(outputStream* st, const void* context, 850 char *buf, int buf_size) { 851 return false; 852 } 853 #endif 854 855 // debugging support (mostly used by debug.cpp but also fatal error handler) 856 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address 857 858 static bool dont_yield(); // when true, JVM_Yield() is nop 859 static void print_statistics(); 860 861 // Thread priority helpers (implemented in OS-specific part) 862 static OSReturn set_native_priority(Thread* thread, int native_prio); 863 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr); 864 static int java_to_os_priority[CriticalPriority + 1]; 865 // Hint to the underlying OS that a task switch would not be good. 866 // Void return because it's a hint and can fail. 867 static const char* native_thread_creation_failed_msg() { 868 return OS_NATIVE_THREAD_CREATION_FAILED_MSG; 869 } 870 871 // Used at creation if requested by the diagnostic flag PauseAtStartup. 872 // Causes the VM to wait until an external stimulus has been applied 873 // (for Unix, that stimulus is a signal, for Windows, an external 874 // ResumeThread call) 875 static void pause(); 876 877 // Builds a platform dependent Agent_OnLoad_<libname> function name 878 // which is used to find statically linked in agents. 879 static char* build_agent_function_name(const char *sym, const char *cname, 880 bool is_absolute_path); 881 882 class SuspendedThreadTaskContext { 883 public: 884 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {} 885 Thread* thread() const { return _thread; } 886 void* ucontext() const { return _ucontext; } 887 private: 888 Thread* _thread; 889 void* _ucontext; 890 }; 891 892 class SuspendedThreadTask { 893 public: 894 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {} 895 void run(); 896 bool is_done() { return _done; } 897 virtual void do_task(const SuspendedThreadTaskContext& context) = 0; 898 protected: 899 ~SuspendedThreadTask() {} 900 private: 901 void internal_do_task(); 902 Thread* _thread; 903 bool _done; 904 }; 905 906 #ifndef _WINDOWS 907 // Suspend/resume support 908 // Protocol: 909 // 910 // a thread starts in SR_RUNNING 911 // 912 // SR_RUNNING can go to 913 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it 914 // SR_SUSPEND_REQUEST can go to 915 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout) 916 // * SR_SUSPENDED if the stopped thread receives the signal and switches state 917 // SR_SUSPENDED can go to 918 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume 919 // SR_WAKEUP_REQUEST can go to 920 // * SR_RUNNING when the stopped thread receives the signal 921 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again) 922 class SuspendResume { 923 public: 924 enum State { 925 SR_RUNNING, 926 SR_SUSPEND_REQUEST, 927 SR_SUSPENDED, 928 SR_WAKEUP_REQUEST 929 }; 930 931 private: 932 volatile State _state; 933 934 private: 935 /* try to switch state from state "from" to state "to" 936 * returns the state set after the method is complete 937 */ 938 State switch_state(State from, State to); 939 940 public: 941 SuspendResume() : _state(SR_RUNNING) { } 942 943 State state() const { return _state; } 944 945 State request_suspend() { 946 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST); 947 } 948 949 State cancel_suspend() { 950 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING); 951 } 952 953 State suspended() { 954 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED); 955 } 956 957 State request_wakeup() { 958 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST); 959 } 960 961 State running() { 962 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING); 963 } 964 965 bool is_running() const { 966 return _state == SR_RUNNING; 967 } 968 969 bool is_suspend_request() const { 970 return _state == SR_SUSPEND_REQUEST; 971 } 972 973 bool is_suspended() const { 974 return _state == SR_SUSPENDED; 975 } 976 }; 977 #endif // !WINDOWS 978 979 980 protected: 981 static volatile unsigned int _rand_seed; // seed for random number generator 982 static int _processor_count; // number of processors 983 static int _initial_active_processor_count; // number of active processors during initialization. 984 985 static char* format_boot_path(const char* format_string, 986 const char* home, 987 int home_len, 988 char fileSep, 989 char pathSep); 990 static bool set_boot_path(char fileSep, char pathSep); 991 992 }; 993 994 #ifndef _WINDOWS 995 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {}; 996 #endif // !_WINDOWS 997 998 // Note that "PAUSE" is almost always used with synchronization 999 // so arguably we should provide Atomic::SpinPause() instead 1000 // of the global SpinPause() with C linkage. 1001 // It'd also be eligible for inlining on many platforms. 1002 1003 extern "C" int SpinPause(); 1004 1005 #endif // SHARE_RUNTIME_OS_HPP