1 /* 2 * Copyright (c) 1997, 2020, 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 class Thread; 51 class JavaThread; 52 class NativeCallStack; 53 class methodHandle; 54 class OSThread; 55 class Mutex; 56 57 template<class E> class GrowableArray; 58 59 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose 60 61 // Platform-independent error return values from OS functions 62 enum OSReturn { 63 OS_OK = 0, // Operation was successful 64 OS_ERR = -1, // Operation failed 65 OS_INTRPT = -2, // Operation was interrupted 66 OS_TIMEOUT = -3, // Operation timed out 67 OS_NOMEM = -5, // Operation failed for lack of memory 68 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource 69 }; 70 71 enum ThreadPriority { // JLS 20.20.1-3 72 NoPriority = -1, // Initial non-priority value 73 MinPriority = 1, // Minimum priority 74 NormPriority = 5, // Normal (non-daemon) priority 75 NearMaxPriority = 9, // High priority, used for VMThread 76 MaxPriority = 10, // Highest priority, used for WatcherThread 77 // ensures that VMThread doesn't starve profiler 78 CriticalPriority = 11 // Critical thread priority 79 }; 80 81 // Executable parameter flag for os::commit_memory() and 82 // os::commit_memory_or_exit(). 83 const bool ExecMem = true; 84 85 // Typedef for structured exception handling support 86 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread); 87 88 class MallocTracker; 89 90 class os: AllStatic { 91 friend class VMStructs; 92 friend class JVMCIVMStructs; 93 friend class MallocTracker; 94 95 #ifdef ASSERT 96 private: 97 static bool _mutex_init_done; 98 public: 99 static void set_mutex_init_done() { _mutex_init_done = true; } 100 static bool mutex_init_done() { return _mutex_init_done; } 101 #endif 102 103 public: 104 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel) 105 106 private: 107 static OSThread* _starting_thread; 108 static address _polling_page; 109 public: 110 static size_t _page_sizes[page_sizes_max]; 111 112 private: 113 static void init_page_sizes(size_t default_page_size) { 114 _page_sizes[0] = default_page_size; 115 _page_sizes[1] = 0; // sentinel 116 } 117 118 static char* pd_reserve_memory(size_t bytes, char* addr = 0, 119 size_t alignment_hint = 0); 120 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr); 121 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc); 122 static void pd_split_reserved_memory(char *base, size_t size, 123 size_t split, bool realloc); 124 static bool pd_commit_memory(char* addr, size_t bytes, bool executable); 125 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 126 bool executable); 127 // Same as pd_commit_memory() that either succeeds or calls 128 // vm_exit_out_of_memory() with the specified mesg. 129 static void pd_commit_memory_or_exit(char* addr, size_t bytes, 130 bool executable, const char* mesg); 131 static void pd_commit_memory_or_exit(char* addr, size_t size, 132 size_t alignment_hint, 133 bool executable, const char* mesg); 134 static bool pd_uncommit_memory(char* addr, size_t bytes); 135 static bool pd_release_memory(char* addr, size_t bytes); 136 137 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset, 138 char *addr, size_t bytes, bool read_only = false, 139 bool allow_exec = false); 140 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset, 141 char *addr, size_t bytes, bool read_only, 142 bool allow_exec); 143 static bool pd_unmap_memory(char *addr, size_t bytes); 144 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint); 145 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint); 146 147 static char* pd_reserve_memory_special(size_t size, size_t alignment, 148 char* addr, bool executable); 149 static bool pd_release_memory_special(char* addr, size_t bytes); 150 151 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned); 152 153 // Get summary strings for system information in buffer provided 154 static void get_summary_cpu_info(char* buf, size_t buflen); 155 static void get_summary_os_info(char* buf, size_t buflen); 156 157 static void initialize_initial_active_processor_count(); 158 159 LINUX_ONLY(static void pd_init_container_support();) 160 161 public: 162 static void init(void); // Called before command line parsing 163 164 static void init_container_support() { // Called during command line parsing. 165 LINUX_ONLY(pd_init_container_support();) 166 } 167 168 static void init_before_ergo(void); // Called after command line parsing 169 // before VM ergonomics processing. 170 static jint init_2(void); // Called after command line parsing 171 // and VM ergonomics processing 172 173 // unset environment variable 174 static bool unsetenv(const char* name); 175 176 static bool have_special_privileges(); 177 178 static jlong javaTimeMillis(); 179 static jlong javaTimeNanos(); 180 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr); 181 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos); 182 static void run_periodic_checks(); 183 static bool supports_monotonic_clock(); 184 185 // Returns the elapsed time in seconds since the vm started. 186 static double elapsedTime(); 187 188 // Returns real time in seconds since an arbitrary point 189 // in the past. 190 static bool getTimesSecs(double* process_real_time, 191 double* process_user_time, 192 double* process_system_time); 193 194 // Interface to the performance counter 195 static jlong elapsed_counter(); 196 static jlong elapsed_frequency(); 197 198 // The "virtual time" of a thread is the amount of time a thread has 199 // actually run. The first function indicates whether the OS supports 200 // this functionality for the current thread, and if so the second 201 // returns the elapsed virtual time for the current thread. 202 static bool supports_vtime(); 203 static double elapsedVTime(); 204 205 // Return current local time in a string (YYYY-MM-DD HH:MM:SS). 206 // It is MT safe, but not async-safe, as reading time zone 207 // information may require a lock on some platforms. 208 static char* local_time_string(char *buf, size_t buflen); 209 static struct tm* localtime_pd (const time_t* clock, struct tm* res); 210 static struct tm* gmtime_pd (const time_t* clock, struct tm* res); 211 // Fill in buffer with current local time as an ISO-8601 string. 212 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz. 213 // Returns buffer, or NULL if it failed. 214 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false); 215 216 // Interface for detecting multiprocessor system 217 static inline bool is_MP() { 218 // During bootstrap if _processor_count is not yet initialized 219 // we claim to be MP as that is safest. If any platform has a 220 // stub generator that might be triggered in this phase and for 221 // which being declared MP when in fact not, is a problem - then 222 // the bootstrap routine for the stub generator needs to check 223 // the processor count directly and leave the bootstrap routine 224 // in place until called after initialization has ocurred. 225 return (_processor_count != 1); 226 } 227 228 static julong available_memory(); 229 static julong physical_memory(); 230 static bool has_allocatable_memory_limit(julong* limit); 231 static bool is_server_class_machine(); 232 233 // Returns the id of the processor on which the calling thread is currently executing. 234 // The returned value is guaranteed to be between 0 and (os::processor_count() - 1). 235 static uint processor_id(); 236 237 // number of CPUs 238 static int processor_count() { 239 return _processor_count; 240 } 241 static void set_processor_count(int count) { _processor_count = count; } 242 243 // Returns the number of CPUs this process is currently allowed to run on. 244 // Note that on some OSes this can change dynamically. 245 static int active_processor_count(); 246 247 // At startup the number of active CPUs this process is allowed to run on. 248 // This value does not change dynamically. May be different from active_processor_count(). 249 static int initial_active_processor_count() { 250 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet."); 251 return _initial_active_processor_count; 252 } 253 254 // Binds the current process to a processor. 255 // Returns true if it worked, false if it didn't. 256 static bool bind_to_processor(uint processor_id); 257 258 // Give a name to the current thread. 259 static void set_native_thread_name(const char *name); 260 261 // Interface for stack banging (predetect possible stack overflow for 262 // exception processing) There are guard pages, and above that shadow 263 // pages for stack overflow checking. 264 static bool uses_stack_guard_pages(); 265 static bool must_commit_stack_guard_pages(); 266 static void map_stack_shadow_pages(address sp); 267 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp); 268 269 // Find committed memory region within specified range (start, start + size), 270 // return true if found any 271 static bool committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size); 272 273 // OS interface to Virtual Memory 274 275 // Return the default page size. 276 static int vm_page_size(); 277 278 // Returns the page size to use for a region of memory. 279 // region_size / min_pages will always be greater than or equal to the 280 // returned value. The returned value will divide region_size. 281 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages); 282 283 // Returns the page size to use for a region of memory. 284 // region_size / min_pages will always be greater than or equal to the 285 // returned value. The returned value might not divide region_size. 286 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages); 287 288 // Return the largest page size that can be used 289 static size_t max_page_size() { 290 // The _page_sizes array is sorted in descending order. 291 return _page_sizes[0]; 292 } 293 294 // Return a lower bound for page sizes. Also works before os::init completed. 295 static size_t min_page_size() { return 4 * K; } 296 297 // Methods for tracing page sizes returned by the above method. 298 // The region_{min,max}_size parameters should be the values 299 // passed to page_size_for_region() and page_size should be the result of that 300 // call. The (optional) base and size parameters should come from the 301 // ReservedSpace base() and size() methods. 302 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count); 303 static void trace_page_sizes(const char* str, 304 const size_t region_min_size, 305 const size_t region_max_size, 306 const size_t page_size, 307 const char* base, 308 const size_t size); 309 static void trace_page_sizes_for_requested_size(const char* str, 310 const size_t requested_size, 311 const size_t page_size, 312 const size_t alignment, 313 const char* base, 314 const size_t size); 315 316 static int vm_allocation_granularity(); 317 static char* reserve_memory(size_t bytes, char* addr = 0, 318 size_t alignment_hint = 0, int file_desc = -1); 319 static char* reserve_memory(size_t bytes, char* addr, 320 size_t alignment_hint, MEMFLAGS flags); 321 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1); 322 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1); 323 static void split_reserved_memory(char *base, size_t size, 324 size_t split, bool realloc); 325 static bool commit_memory(char* addr, size_t bytes, bool executable); 326 static bool commit_memory(char* addr, size_t size, size_t alignment_hint, 327 bool executable); 328 // Same as commit_memory() that either succeeds or calls 329 // vm_exit_out_of_memory() with the specified mesg. 330 static void commit_memory_or_exit(char* addr, size_t bytes, 331 bool executable, const char* mesg); 332 static void commit_memory_or_exit(char* addr, size_t size, 333 size_t alignment_hint, 334 bool executable, const char* mesg); 335 static bool uncommit_memory(char* addr, size_t bytes); 336 static bool release_memory(char* addr, size_t bytes); 337 338 // Touch memory pages that cover the memory range from start to end (exclusive) 339 // to make the OS back the memory range with actual memory. 340 // Current implementation may not touch the last page if unaligned addresses 341 // are passed. 342 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size()); 343 344 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX }; 345 static bool protect_memory(char* addr, size_t bytes, ProtType prot, 346 bool is_committed = true); 347 348 static bool guard_memory(char* addr, size_t bytes); 349 static bool unguard_memory(char* addr, size_t bytes); 350 static bool create_stack_guard_pages(char* addr, size_t bytes); 351 static bool pd_create_stack_guard_pages(char* addr, size_t bytes); 352 static bool remove_stack_guard_pages(char* addr, size_t bytes); 353 // Helper function to create a new file with template jvmheap.XXXXXX. 354 // Returns a valid fd on success or else returns -1 355 static int create_file_for_heap(const char* dir); 356 // Map memory to the file referred by fd. This function is slightly different from map_memory() 357 // and is added to be used for implementation of -XX:AllocateHeapAt 358 static char* map_memory_to_file(char* base, size_t size, int fd); 359 // Replace existing reserved memory with file mapping 360 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd); 361 362 static char* map_memory(int fd, const char* file_name, size_t file_offset, 363 char *addr, size_t bytes, bool read_only = false, 364 bool allow_exec = false); 365 static char* remap_memory(int fd, const char* file_name, size_t file_offset, 366 char *addr, size_t bytes, bool read_only, 367 bool allow_exec); 368 static bool unmap_memory(char *addr, size_t bytes); 369 static void free_memory(char *addr, size_t bytes, size_t alignment_hint); 370 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint); 371 372 // NUMA-specific interface 373 static bool numa_has_static_binding(); 374 static bool numa_has_group_homing(); 375 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint); 376 static void numa_make_global(char *addr, size_t bytes); 377 static size_t numa_get_groups_num(); 378 static size_t numa_get_leaf_groups(int *ids, size_t size); 379 static bool numa_topology_changed(); 380 static int numa_get_group_id(); 381 static int numa_get_group_id_for_address(const void* address); 382 383 // Page manipulation 384 struct page_info { 385 size_t size; 386 int lgrp_id; 387 }; 388 static bool get_page_info(char *start, page_info* info); 389 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found); 390 391 static char* non_memory_address_word(); 392 // reserve, commit and pin the entire memory region 393 static char* reserve_memory_special(size_t size, size_t alignment, 394 char* addr, bool executable); 395 static bool release_memory_special(char* addr, size_t bytes); 396 static void large_page_init(); 397 static size_t large_page_size(); 398 static bool can_commit_large_page_memory(); 399 static bool can_execute_large_page_memory(); 400 401 // Check if pointer points to readable memory (by 4-byte read access) 402 static bool is_readable_pointer(const void* p); 403 static bool is_readable_range(const void* from, const void* to); 404 405 // threads 406 407 enum ThreadType { 408 vm_thread, 409 cgc_thread, // Concurrent GC thread 410 pgc_thread, // Parallel GC thread 411 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads. 412 compiler_thread, 413 watcher_thread, 414 os_thread 415 }; 416 417 static bool create_thread(Thread* thread, 418 ThreadType thr_type, 419 size_t req_stack_size = 0); 420 421 // The "main thread", also known as "starting thread", is the thread 422 // that loads/creates the JVM via JNI_CreateJavaVM. 423 static bool create_main_thread(JavaThread* thread); 424 425 // The primordial thread is the initial process thread. The java 426 // launcher never uses the primordial thread as the main thread, but 427 // applications that host the JVM directly may do so. Some platforms 428 // need special-case handling of the primordial thread if it attaches 429 // to the VM. 430 static bool is_primordial_thread(void) 431 #if defined(_WINDOWS) || defined(BSD) 432 // No way to identify the primordial thread. 433 { return false; } 434 #else 435 ; 436 #endif 437 438 static bool create_attached_thread(JavaThread* thread); 439 static void pd_start_thread(Thread* thread); 440 static void start_thread(Thread* thread); 441 442 // Returns true if successful. 443 static bool signal_thread(Thread* thread, int sig, const char* reason); 444 445 static void free_thread(OSThread* osthread); 446 447 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit 448 static intx current_thread_id(); 449 static int current_process_id(); 450 451 // Short standalone OS sleep routines suitable for slow path spin loop. 452 // Ignores safepoints/suspension/Thread.interrupt() (so keep it short). 453 // ms/ns = 0, will sleep for the least amount of time allowed by the OS. 454 // Maximum sleep time is just under 1 second. 455 static void naked_short_sleep(jlong ms); 456 static void naked_short_nanosleep(jlong ns); 457 // Longer standalone OS sleep routine - a convenience wrapper around 458 // multiple calls to naked_short_sleep. Only for use by non-JavaThreads. 459 static void naked_sleep(jlong millis); 460 // Never returns, use with CAUTION 461 static void infinite_sleep(); 462 static void naked_yield () ; 463 static OSReturn set_priority(Thread* thread, ThreadPriority priority); 464 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority); 465 466 static int pd_self_suspend_thread(Thread* thread); 467 468 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp); 469 static frame fetch_frame_from_context(const void* ucVoid); 470 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid); 471 472 static void breakpoint(); 473 static bool start_debugging(char *buf, int buflen); 474 475 static address current_stack_pointer(); 476 static address current_stack_base(); 477 static size_t current_stack_size(); 478 479 static void verify_stack_alignment() PRODUCT_RETURN; 480 481 static bool message_box(const char* title, const char* message); 482 483 // run cmd in a separate process and return its exit code; or -1 on failures 484 static int fork_and_exec(char *cmd, bool use_vfork_if_available = false); 485 486 // Call ::exit() on all platforms but Windows 487 static void exit(int num); 488 489 // Terminate the VM, but don't exit the process 490 static void shutdown(); 491 492 // Terminate with an error. Default is to generate a core file on platforms 493 // that support such things. This calls shutdown() and then aborts. 494 static void abort(bool dump_core, void *siginfo, const void *context); 495 static void abort(bool dump_core = true); 496 497 // Die immediately, no exit hook, no abort hook, no cleanup. 498 // Dump a core file, if possible, for debugging. os::abort() is the 499 // preferred means to abort the VM on error. os::die() should only 500 // be called if something has gone badly wrong. CreateCoredumpOnCrash 501 // is intentionally not honored by this function. 502 static void die(); 503 504 // File i/o operations 505 static int open(const char *path, int oflag, int mode); 506 static FILE* open(int fd, const char* mode); 507 static FILE* fopen(const char* path, const char* mode); 508 static int close(int fd); 509 static jlong lseek(int fd, jlong offset, int whence); 510 // This function, on Windows, canonicalizes a given path (see os_windows.cpp for details). 511 // On Posix, this function is a noop: it does not change anything and just returns 512 // the input pointer. 513 static char* native_path(char *path); 514 static int ftruncate(int fd, jlong length); 515 static int fsync(int fd); 516 static int available(int fd, jlong *bytes); 517 static int get_fileno(FILE* fp); 518 static void flockfile(FILE* fp); 519 static void funlockfile(FILE* fp); 520 521 static int compare_file_modified_times(const char* file1, const char* file2); 522 523 static bool same_files(const char* file1, const char* file2); 524 525 //File i/o operations 526 527 static ssize_t read(int fd, void *buf, unsigned int nBytes); 528 static ssize_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset); 529 static size_t write(int fd, const void *buf, unsigned int nBytes); 530 531 // Reading directories. 532 static DIR* opendir(const char* dirname); 533 static struct dirent* readdir(DIR* dirp); 534 static int closedir(DIR* dirp); 535 536 // Dynamic library extension 537 static const char* dll_file_extension(); 538 539 static const char* get_temp_directory(); 540 static const char* get_current_directory(char *buf, size_t buflen); 541 542 // Builds the platform-specific name of a library. 543 // Returns false if the buffer is too small. 544 static bool dll_build_name(char* buffer, size_t size, 545 const char* fname); 546 547 // Builds a platform-specific full library path given an ld path and 548 // unadorned library name. Returns true if the buffer contains a full 549 // path to an existing file, false otherwise. If pathname is empty, 550 // uses the path to the current directory. 551 static bool dll_locate_lib(char* buffer, size_t size, 552 const char* pathname, const char* fname); 553 554 // Symbol lookup, find nearest function name; basically it implements 555 // dladdr() for all platforms. Name of the nearest function is copied 556 // to buf. Distance from its base address is optionally returned as offset. 557 // If function name is not found, buf[0] is set to '\0' and offset is 558 // set to -1 (if offset is non-NULL). 559 static bool dll_address_to_function_name(address addr, char* buf, 560 int buflen, int* offset, 561 bool demangle = true); 562 563 // Locate DLL/DSO. On success, full path of the library is copied to 564 // buf, and offset is optionally set to be the distance between addr 565 // and the library's base address. On failure, buf[0] is set to '\0' 566 // and offset is set to -1 (if offset is non-NULL). 567 static bool dll_address_to_library_name(address addr, char* buf, 568 int buflen, int* offset); 569 570 // Find out whether the pc is in the static code for jvm.dll/libjvm.so. 571 static bool address_is_in_vm(address addr); 572 573 // Loads .dll/.so and 574 // in case of error it checks if .dll/.so was built for the 575 // same architecture as HotSpot is running on 576 // in case of an error NULL is returned and an error message is stored in ebuf 577 static void* dll_load(const char *name, char *ebuf, int ebuflen); 578 579 // lookup symbol in a shared library 580 static void* dll_lookup(void* handle, const char* name); 581 582 // Unload library 583 static void dll_unload(void *lib); 584 585 // Callback for loaded module information 586 // Input parameters: 587 // char* module_file_name, 588 // address module_base_addr, 589 // address module_top_addr, 590 // void* param 591 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *); 592 593 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param); 594 595 // Return the handle of this process 596 static void* get_default_process_handle(); 597 598 // Check for static linked agent library 599 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 600 size_t syms_len); 601 602 // Find agent entry point 603 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib, 604 const char *syms[], size_t syms_len); 605 606 // Provide C99 compliant versions of these functions, since some versions 607 // of some platforms don't. 608 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0); 609 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4); 610 611 // Get host name in buffer provided 612 static bool get_host_name(char* buf, size_t buflen); 613 614 // Print out system information; they are called by fatal error handler. 615 // Output format may be different on different platforms. 616 static void print_os_info(outputStream* st); 617 static void print_os_info_brief(outputStream* st); 618 static void print_cpu_info(outputStream* st, char* buf, size_t buflen); 619 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen); 620 static void print_summary_info(outputStream* st, char* buf, size_t buflen); 621 static void print_memory_info(outputStream* st); 622 static void print_dll_info(outputStream* st); 623 static void print_environment_variables(outputStream* st, const char** env_list); 624 static void print_context(outputStream* st, const void* context); 625 static void print_register_info(outputStream* st, const void* context); 626 static bool signal_sent_by_kill(const void* siginfo); 627 static void print_siginfo(outputStream* st, const void* siginfo); 628 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen); 629 static void print_date_and_time(outputStream* st, char* buf, size_t buflen); 630 static void print_instructions(outputStream* st, address pc, int unitsize); 631 632 // helper for output of seconds in days , hours and months 633 static void print_dhm(outputStream* st, const char* startStr, long sec); 634 635 static void print_location(outputStream* st, intptr_t x, bool verbose = false); 636 static size_t lasterror(char *buf, size_t len); 637 static int get_last_error(); 638 639 // Replacement for strerror(). 640 // Will return the english description of the error (e.g. "File not found", as 641 // suggested in the POSIX standard. 642 // Will return "Unknown error" for an unknown errno value. 643 // Will not attempt to localize the returned string. 644 // Will always return a valid string which is a static constant. 645 // Will not change the value of errno. 646 static const char* strerror(int e); 647 648 // Will return the literalized version of the given errno (e.g. "EINVAL" 649 // for EINVAL). 650 // Will return "Unknown error" for an unknown errno value. 651 // Will always return a valid string which is a static constant. 652 // Will not change the value of errno. 653 static const char* errno_name(int e); 654 655 // wait for a key press if PauseAtExit is set 656 static void wait_for_keypress_at_exit(void); 657 658 // The following two functions are used by fatal error handler to trace 659 // native (C) frames. They are not part of frame.hpp/frame.cpp because 660 // frame.hpp/cpp assume thread is JavaThread, and also because different 661 // OS/compiler may have different convention or provide different API to 662 // walk C frames. 663 // 664 // We don't attempt to become a debugger, so we only follow frames if that 665 // does not require a lookup in the unwind table, which is part of the binary 666 // file but may be unsafe to read after a fatal error. So on x86, we can 667 // only walk stack if %ebp is used as frame pointer; on ia64, it's not 668 // possible to walk C stack without having the unwind table. 669 static bool is_first_C_frame(frame *fr); 670 static frame get_sender_for_C_frame(frame *fr); 671 672 // return current frame. pc() and sp() are set to NULL on failure. 673 static frame current_frame(); 674 675 static void print_hex_dump(outputStream* st, address start, address end, int unitsize); 676 677 // returns a string to describe the exception/signal; 678 // returns NULL if exception_code is not an OS exception/signal. 679 static const char* exception_name(int exception_code, char* buf, size_t buflen); 680 681 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV). 682 static int get_signal_number(const char* signal_name); 683 684 // Returns native Java library, loads if necessary 685 static void* native_java_library(); 686 687 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler) 688 static void jvm_path(char *buf, jint buflen); 689 690 // JNI names 691 static void print_jni_name_prefix_on(outputStream* st, int args_size); 692 static void print_jni_name_suffix_on(outputStream* st, int args_size); 693 694 // Init os specific system properties values 695 static void init_system_properties_values(); 696 697 // IO operations, non-JVM_ version. 698 static int stat(const char* path, struct stat* sbuf); 699 static bool dir_is_empty(const char* path); 700 701 // IO operations on binary files 702 static int create_binary_file(const char* path, bool rewrite_existing); 703 static jlong current_file_offset(int fd); 704 static jlong seek_to_file_offset(int fd, jlong offset); 705 706 // Retrieve native stack frames. 707 // Parameter: 708 // stack: an array to storage stack pointers. 709 // frames: size of above array. 710 // toSkip: number of stack frames to skip at the beginning. 711 // Return: number of stack frames captured. 712 static int get_native_stack(address* stack, int size, int toSkip = 0); 713 714 // General allocation (must be MT-safe) 715 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack); 716 static void* malloc (size_t size, MEMFLAGS flags); 717 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack); 718 static void* realloc (void *memblock, size_t size, MEMFLAGS flag); 719 720 // handles NULL pointers 721 static void free (void *memblock); 722 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup 723 // Like strdup, but exit VM when strdup() returns NULL 724 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal); 725 726 #ifndef PRODUCT 727 static julong num_mallocs; // # of calls to malloc/realloc 728 static julong alloc_bytes; // # of bytes allocated 729 static julong num_frees; // # of calls to free 730 static julong free_bytes; // # of bytes freed 731 #endif 732 733 // SocketInterface (ex HPI SocketInterface ) 734 static int socket(int domain, int type, int protocol); 735 static int socket_close(int fd); 736 static int recv(int fd, char* buf, size_t nBytes, uint flags); 737 static int send(int fd, char* buf, size_t nBytes, uint flags); 738 static int raw_send(int fd, char* buf, size_t nBytes, uint flags); 739 static int connect(int fd, struct sockaddr* him, socklen_t len); 740 static struct hostent* get_host_by_name(char* name); 741 742 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal) 743 static void initialize_jdk_signal_support(TRAPS); 744 static void signal_notify(int signal_number); 745 static void* signal(int signal_number, void* handler); 746 static void signal_raise(int signal_number); 747 static int signal_wait(); 748 static void* user_handler(); 749 static void terminate_signal_thread(); 750 static int sigexitnum_pd(); 751 752 // random number generation 753 static int random(); // return 32bit pseudorandom number 754 static void init_random(unsigned int initval); // initialize random sequence 755 756 // Structured OS Exception support 757 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread); 758 759 // On Posix compatible OS it will simply check core dump limits while on Windows 760 // it will check if dump file can be created. Check or prepare a core dump to be 761 // taken at a later point in the same thread in os::abort(). Use the caller 762 // provided buffer as a scratch buffer. The status message which will be written 763 // into the error log either is file location or a short error message, depending 764 // on the checking result. 765 static void check_dump_limit(char* buffer, size_t bufferSize); 766 767 // Get the default path to the core file 768 // Returns the length of the string 769 static int get_core_path(char* buffer, size_t bufferSize); 770 771 // JVMTI & JVM monitoring and management support 772 // The thread_cpu_time() and current_thread_cpu_time() are only 773 // supported if is_thread_cpu_time_supported() returns true. 774 // They are not supported on Solaris T1. 775 776 // Thread CPU Time - return the fast estimate on a platform 777 // On Solaris - call gethrvtime (fast) - user time only 778 // On Linux - fast clock_gettime where available - user+sys 779 // - otherwise: very slow /proc fs - user+sys 780 // On Windows - GetThreadTimes - user+sys 781 static jlong current_thread_cpu_time(); 782 static jlong thread_cpu_time(Thread* t); 783 784 // Thread CPU Time with user_sys_cpu_time parameter. 785 // 786 // If user_sys_cpu_time is true, user+sys time is returned. 787 // Otherwise, only user time is returned 788 static jlong current_thread_cpu_time(bool user_sys_cpu_time); 789 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time); 790 791 // Return a bunch of info about the timers. 792 // Note that the returned info for these two functions may be different 793 // on some platforms 794 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 795 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 796 797 static bool is_thread_cpu_time_supported(); 798 799 // System loadavg support. Returns -1 if load average cannot be obtained. 800 static int loadavg(double loadavg[], int nelem); 801 802 // Amount beyond the callee frame size that we bang the stack. 803 static int extra_bang_size_in_bytes(); 804 805 static char** split_path(const char* path, size_t* elements, size_t file_name_length); 806 807 // support for mapping non-volatile memory using MAP_SYNC 808 static bool supports_map_sync(); 809 810 public: 811 class CrashProtectionCallback : public StackObj { 812 public: 813 virtual void call() = 0; 814 }; 815 816 // Platform dependent stuff 817 #ifndef _WINDOWS 818 # include "os_posix.hpp" 819 #endif 820 #include OS_CPU_HEADER(os) 821 #include OS_HEADER(os) 822 823 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG 824 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached" 825 #endif 826 827 public: 828 #ifndef PLATFORM_PRINT_NATIVE_STACK 829 // No platform-specific code for printing the native stack. 830 static bool platform_print_native_stack(outputStream* st, const void* context, 831 char *buf, int buf_size) { 832 return false; 833 } 834 #endif 835 836 // debugging support (mostly used by debug.cpp but also fatal error handler) 837 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address 838 839 static bool dont_yield(); // when true, JVM_Yield() is nop 840 static void print_statistics(); 841 842 // Thread priority helpers (implemented in OS-specific part) 843 static OSReturn set_native_priority(Thread* thread, int native_prio); 844 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr); 845 static int java_to_os_priority[CriticalPriority + 1]; 846 // Hint to the underlying OS that a task switch would not be good. 847 // Void return because it's a hint and can fail. 848 static const char* native_thread_creation_failed_msg() { 849 return OS_NATIVE_THREAD_CREATION_FAILED_MSG; 850 } 851 852 // Used at creation if requested by the diagnostic flag PauseAtStartup. 853 // Causes the VM to wait until an external stimulus has been applied 854 // (for Unix, that stimulus is a signal, for Windows, an external 855 // ResumeThread call) 856 static void pause(); 857 858 // Builds a platform dependent Agent_OnLoad_<libname> function name 859 // which is used to find statically linked in agents. 860 static char* build_agent_function_name(const char *sym, const char *cname, 861 bool is_absolute_path); 862 863 class SuspendedThreadTaskContext { 864 public: 865 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {} 866 Thread* thread() const { return _thread; } 867 void* ucontext() const { return _ucontext; } 868 private: 869 Thread* _thread; 870 void* _ucontext; 871 }; 872 873 class SuspendedThreadTask { 874 public: 875 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {} 876 void run(); 877 bool is_done() { return _done; } 878 virtual void do_task(const SuspendedThreadTaskContext& context) = 0; 879 protected: 880 ~SuspendedThreadTask() {} 881 private: 882 void internal_do_task(); 883 Thread* _thread; 884 bool _done; 885 }; 886 887 #ifndef _WINDOWS 888 // Suspend/resume support 889 // Protocol: 890 // 891 // a thread starts in SR_RUNNING 892 // 893 // SR_RUNNING can go to 894 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it 895 // SR_SUSPEND_REQUEST can go to 896 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout) 897 // * SR_SUSPENDED if the stopped thread receives the signal and switches state 898 // SR_SUSPENDED can go to 899 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume 900 // SR_WAKEUP_REQUEST can go to 901 // * SR_RUNNING when the stopped thread receives the signal 902 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again) 903 class SuspendResume { 904 public: 905 enum State { 906 SR_RUNNING, 907 SR_SUSPEND_REQUEST, 908 SR_SUSPENDED, 909 SR_WAKEUP_REQUEST 910 }; 911 912 private: 913 volatile State _state; 914 915 private: 916 /* try to switch state from state "from" to state "to" 917 * returns the state set after the method is complete 918 */ 919 State switch_state(State from, State to); 920 921 public: 922 SuspendResume() : _state(SR_RUNNING) { } 923 924 State state() const { return _state; } 925 926 State request_suspend() { 927 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST); 928 } 929 930 State cancel_suspend() { 931 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING); 932 } 933 934 State suspended() { 935 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED); 936 } 937 938 State request_wakeup() { 939 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST); 940 } 941 942 State running() { 943 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING); 944 } 945 946 bool is_running() const { 947 return _state == SR_RUNNING; 948 } 949 950 bool is_suspended() const { 951 return _state == SR_SUSPENDED; 952 } 953 }; 954 #endif // !WINDOWS 955 956 957 protected: 958 static volatile unsigned int _rand_seed; // seed for random number generator 959 static int _processor_count; // number of processors 960 static int _initial_active_processor_count; // number of active processors during initialization. 961 962 static char* format_boot_path(const char* format_string, 963 const char* home, 964 int home_len, 965 char fileSep, 966 char pathSep); 967 static bool set_boot_path(char fileSep, char pathSep); 968 969 }; 970 971 #ifndef _WINDOWS 972 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {}; 973 #endif // !_WINDOWS 974 975 // Note that "PAUSE" is almost always used with synchronization 976 // so arguably we should provide Atomic::SpinPause() instead 977 // of the global SpinPause() with C linkage. 978 // It'd also be eligible for inlining on many platforms. 979 980 extern "C" int SpinPause(); 981 982 #endif // SHARE_RUNTIME_OS_HPP