1 /* 2 * Copyright (c) 1997, 2014, 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 "jvmtifiles/jvmti.h" 29 #include "runtime/extendedPC.hpp" 30 #include "runtime/handles.hpp" 31 #include "utilities/top.hpp" 32 #ifdef TARGET_OS_FAMILY_linux 33 # include "jvm_linux.h" 34 # include <setjmp.h> 35 #endif 36 #ifdef TARGET_OS_FAMILY_solaris 37 # include "jvm_solaris.h" 38 # include <setjmp.h> 39 #endif 40 #ifdef TARGET_OS_FAMILY_windows 41 # include "jvm_windows.h" 42 #endif 43 #ifdef TARGET_OS_FAMILY_aix 44 # include "jvm_aix.h" 45 # include <setjmp.h> 46 #endif 47 #ifdef TARGET_OS_FAMILY_bsd 48 # include "jvm_bsd.h" 49 # include <setjmp.h> 50 # ifdef __APPLE__ 51 # include <mach/mach_time.h> 52 # endif 53 #endif 54 55 class AgentLibrary; 56 57 // os defines the interface to operating system; this includes traditional 58 // OS services (time, I/O) as well as other functionality with system- 59 // dependent code. 60 61 typedef void (*dll_func)(...); 62 63 class Thread; 64 class JavaThread; 65 class Event; 66 class DLL; 67 class FileHandle; 68 class NativeCallStack; 69 70 template<class E> class GrowableArray; 71 72 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose 73 74 // Platform-independent error return values from OS functions 75 enum OSReturn { 76 OS_OK = 0, // Operation was successful 77 OS_ERR = -1, // Operation failed 78 OS_INTRPT = -2, // Operation was interrupted 79 OS_TIMEOUT = -3, // Operation timed out 80 OS_NOMEM = -5, // Operation failed for lack of memory 81 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource 82 }; 83 84 enum ThreadPriority { // JLS 20.20.1-3 85 NoPriority = -1, // Initial non-priority value 86 MinPriority = 1, // Minimum priority 87 NormPriority = 5, // Normal (non-daemon) priority 88 NearMaxPriority = 9, // High priority, used for VMThread 89 MaxPriority = 10, // Highest priority, used for WatcherThread 90 // ensures that VMThread doesn't starve profiler 91 CriticalPriority = 11 // Critical thread priority 92 }; 93 94 // Executable parameter flag for os::commit_memory() and 95 // os::commit_memory_or_exit(). 96 const bool ExecMem = true; 97 98 // Typedef for structured exception handling support 99 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread); 100 101 class MallocTracker; 102 103 class os: AllStatic { 104 friend class VMStructs; 105 friend class MallocTracker; 106 public: 107 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel) 108 109 private: 110 static OSThread* _starting_thread; 111 static address _polling_page; 112 static volatile int32_t * _mem_serialize_page; 113 static uintptr_t _serialize_page_mask; 114 public: 115 static size_t _page_sizes[page_sizes_max]; 116 117 private: 118 static void init_page_sizes(size_t default_page_size) { 119 _page_sizes[0] = default_page_size; 120 _page_sizes[1] = 0; // sentinel 121 } 122 123 static char* pd_reserve_memory(size_t bytes, char* addr = 0, 124 size_t alignment_hint = 0); 125 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr); 126 static void pd_split_reserved_memory(char *base, size_t size, 127 size_t split, bool realloc); 128 static bool pd_commit_memory(char* addr, size_t bytes, bool executable); 129 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 130 bool executable); 131 // Same as pd_commit_memory() that either succeeds or calls 132 // vm_exit_out_of_memory() with the specified mesg. 133 static void pd_commit_memory_or_exit(char* addr, size_t bytes, 134 bool executable, const char* mesg); 135 static void pd_commit_memory_or_exit(char* addr, size_t size, 136 size_t alignment_hint, 137 bool executable, const char* mesg); 138 static bool pd_uncommit_memory(char* addr, size_t bytes); 139 static bool pd_release_memory(char* addr, size_t bytes); 140 141 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset, 142 char *addr, size_t bytes, bool read_only = false, 143 bool allow_exec = false); 144 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset, 145 char *addr, size_t bytes, bool read_only, 146 bool allow_exec); 147 static bool pd_unmap_memory(char *addr, size_t bytes); 148 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint); 149 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint); 150 151 152 public: 153 static void init(void); // Called before command line parsing 154 static void init_before_ergo(void); // Called after command line parsing 155 // before VM ergonomics processing. 156 static jint init_2(void); // Called after command line parsing 157 // and VM ergonomics processing 158 static void init_globals(void) { // Called from init_globals() in init.cpp 159 init_globals_ext(); 160 } 161 static void init_3(void); // Called at the end of vm init 162 163 // File names are case-insensitive on windows only 164 // Override me as needed 165 static int file_name_strcmp(const char* s1, const char* s2); 166 167 // get/unset environment variable 168 static bool getenv(const char* name, char* buffer, int len); 169 static bool unsetenv(const char* name); 170 171 static bool have_special_privileges(); 172 173 static jlong javaTimeMillis(); 174 static jlong javaTimeNanos(); 175 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr); 176 static void run_periodic_checks(); 177 static bool supports_monotonic_clock(); 178 179 180 // Returns the elapsed time in seconds since the vm started. 181 static double elapsedTime(); 182 183 // Returns real time in seconds since an arbitrary point 184 // in the past. 185 static bool getTimesSecs(double* process_real_time, 186 double* process_user_time, 187 double* process_system_time); 188 189 // Interface to the performance counter 190 static jlong elapsed_counter(); 191 static jlong elapsed_frequency(); 192 193 // The "virtual time" of a thread is the amount of time a thread has 194 // actually run. The first function indicates whether the OS supports 195 // this functionality for the current thread, and if so: 196 // * the second enables vtime tracking (if that is required). 197 // * the third tells whether vtime is enabled. 198 // * the fourth returns the elapsed virtual time for the current 199 // thread. 200 static bool supports_vtime(); 201 static bool enable_vtime(); 202 static bool vtime_enabled(); 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 // Fill in buffer with current local time as an ISO-8601 string. 211 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz. 212 // Returns buffer, or NULL if it failed. 213 static char* iso8601_time(char* buffer, size_t buffer_length); 214 215 // Interface for detecting multiprocessor system 216 static inline bool is_MP() { 217 #if !INCLUDE_NMT 218 assert(_processor_count > 0, "invalid processor count"); 219 return _processor_count > 1 || AssumeMP; 220 #else 221 // NMT needs atomic operations before this initialization. 222 return true; 223 #endif 224 } 225 static julong available_memory(); 226 static julong physical_memory(); 227 static bool has_allocatable_memory_limit(julong* limit); 228 static bool is_server_class_machine(); 229 230 // number of CPUs 231 static int processor_count() { 232 return _processor_count; 233 } 234 static void set_processor_count(int count) { _processor_count = count; } 235 236 // Returns the number of CPUs this process is currently allowed to run on. 237 // Note that on some OSes this can change dynamically. 238 static int active_processor_count(); 239 240 // Bind processes to processors. 241 // This is a two step procedure: 242 // first you generate a distribution of processes to processors, 243 // then you bind processes according to that distribution. 244 // Compute a distribution for number of processes to processors. 245 // Stores the processor id's into the distribution array argument. 246 // Returns true if it worked, false if it didn't. 247 static bool distribute_processes(uint length, uint* distribution); 248 // Binds the current process to a processor. 249 // Returns true if it worked, false if it didn't. 250 static bool bind_to_processor(uint processor_id); 251 252 // Give a name to the current thread. 253 static void set_native_thread_name(const char *name); 254 255 // Interface for stack banging (predetect possible stack overflow for 256 // exception processing) There are guard pages, and above that shadow 257 // pages for stack overflow checking. 258 static bool uses_stack_guard_pages(); 259 static bool allocate_stack_guard_pages(); 260 static void bang_stack_shadow_pages(); 261 static bool stack_shadow_pages_available(Thread *thread, methodHandle method); 262 263 // OS interface to Virtual Memory 264 265 // Return the default page size. 266 static int vm_page_size(); 267 268 // Return the page size to use for a region of memory. The min_pages argument 269 // is a hint intended to limit fragmentation; it says the returned page size 270 // should be <= region_max_size / min_pages. Because min_pages is a hint, 271 // this routine may return a size larger than region_max_size / min_pages. 272 // 273 // The current implementation ignores min_pages if a larger page size is an 274 // exact multiple of both region_min_size and region_max_size. This allows 275 // larger pages to be used when doing so would not cause fragmentation; in 276 // particular, a single page can be used when region_min_size == 277 // region_max_size == a supported page size. 278 static size_t page_size_for_region(size_t region_min_size, 279 size_t region_max_size, 280 uint min_pages); 281 // Return the largest page size that can be used 282 static size_t max_page_size() { 283 // The _page_sizes array is sorted in descending order. 284 return _page_sizes[0]; 285 } 286 287 // Methods for tracing page sizes returned by the above method; enabled by 288 // TracePageSizes. The region_{min,max}_size parameters should be the values 289 // passed to page_size_for_region() and page_size should be the result of that 290 // call. The (optional) base and size parameters should come from the 291 // ReservedSpace base() and size() methods. 292 static void trace_page_sizes(const char* str, const size_t* page_sizes, 293 int count) PRODUCT_RETURN; 294 static void trace_page_sizes(const char* str, const size_t region_min_size, 295 const size_t region_max_size, 296 const size_t page_size, 297 const char* base = NULL, 298 const size_t size = 0) PRODUCT_RETURN; 299 300 static int vm_allocation_granularity(); 301 static char* reserve_memory(size_t bytes, char* addr = 0, 302 size_t alignment_hint = 0); 303 static char* reserve_memory(size_t bytes, char* addr, 304 size_t alignment_hint, MEMFLAGS flags); 305 static char* reserve_memory_aligned(size_t size, size_t alignment); 306 static char* attempt_reserve_memory_at(size_t bytes, char* addr); 307 static void split_reserved_memory(char *base, size_t size, 308 size_t split, bool realloc); 309 static bool commit_memory(char* addr, size_t bytes, bool executable); 310 static bool commit_memory(char* addr, size_t size, size_t alignment_hint, 311 bool executable); 312 // Same as commit_memory() that either succeeds or calls 313 // vm_exit_out_of_memory() with the specified mesg. 314 static void commit_memory_or_exit(char* addr, size_t bytes, 315 bool executable, const char* mesg); 316 static void commit_memory_or_exit(char* addr, size_t size, 317 size_t alignment_hint, 318 bool executable, const char* mesg); 319 static bool uncommit_memory(char* addr, size_t bytes); 320 static bool release_memory(char* addr, size_t bytes); 321 322 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX }; 323 static bool protect_memory(char* addr, size_t bytes, ProtType prot, 324 bool is_committed = true); 325 326 static bool guard_memory(char* addr, size_t bytes); 327 static bool unguard_memory(char* addr, size_t bytes); 328 static bool create_stack_guard_pages(char* addr, size_t bytes); 329 static bool pd_create_stack_guard_pages(char* addr, size_t bytes); 330 static bool remove_stack_guard_pages(char* addr, size_t bytes); 331 332 static char* map_memory(int fd, const char* file_name, size_t file_offset, 333 char *addr, size_t bytes, bool read_only = false, 334 bool allow_exec = false); 335 static char* remap_memory(int fd, const char* file_name, size_t file_offset, 336 char *addr, size_t bytes, bool read_only, 337 bool allow_exec); 338 static bool unmap_memory(char *addr, size_t bytes); 339 static void free_memory(char *addr, size_t bytes, size_t alignment_hint); 340 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint); 341 342 // NUMA-specific interface 343 static bool numa_has_static_binding(); 344 static bool numa_has_group_homing(); 345 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint); 346 static void numa_make_global(char *addr, size_t bytes); 347 static size_t numa_get_groups_num(); 348 static size_t numa_get_leaf_groups(int *ids, size_t size); 349 static bool numa_topology_changed(); 350 static int numa_get_group_id(); 351 352 // Page manipulation 353 struct page_info { 354 size_t size; 355 int lgrp_id; 356 }; 357 static bool get_page_info(char *start, page_info* info); 358 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found); 359 360 static char* non_memory_address_word(); 361 // reserve, commit and pin the entire memory region 362 static char* reserve_memory_special(size_t size, size_t alignment, 363 char* addr, bool executable); 364 static bool release_memory_special(char* addr, size_t bytes); 365 static void large_page_init(); 366 static size_t large_page_size(); 367 static bool can_commit_large_page_memory(); 368 static bool can_execute_large_page_memory(); 369 370 // OS interface to polling page 371 static address get_polling_page() { return _polling_page; } 372 static void set_polling_page(address page) { _polling_page = page; } 373 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); } 374 static void make_polling_page_unreadable(); 375 static void make_polling_page_readable(); 376 377 // Routines used to serialize the thread state without using membars 378 static void serialize_thread_states(); 379 380 // Since we write to the serialize page from every thread, we 381 // want stores to be on unique cache lines whenever possible 382 // in order to minimize CPU cross talk. We pre-compute the 383 // amount to shift the thread* to make this offset unique to 384 // each thread. 385 static int get_serialize_page_shift_count() { 386 return SerializePageShiftCount; 387 } 388 389 static void set_serialize_page_mask(uintptr_t mask) { 390 _serialize_page_mask = mask; 391 } 392 393 static unsigned int get_serialize_page_mask() { 394 return _serialize_page_mask; 395 } 396 397 static void set_memory_serialize_page(address page); 398 399 static address get_memory_serialize_page() { 400 return (address)_mem_serialize_page; 401 } 402 403 static inline void write_memory_serialize_page(JavaThread *thread) { 404 uintptr_t page_offset = ((uintptr_t)thread >> 405 get_serialize_page_shift_count()) & 406 get_serialize_page_mask(); 407 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1; 408 } 409 410 static bool is_memory_serialize_page(JavaThread *thread, address addr) { 411 if (UseMembar) return false; 412 // Previously this function calculated the exact address of this 413 // thread's serialize page, and checked if the faulting address 414 // was equal. However, some platforms mask off faulting addresses 415 // to the page size, so now we just check that the address is 416 // within the page. This makes the thread argument unnecessary, 417 // but we retain the NULL check to preserve existing behavior. 418 if (thread == NULL) return false; 419 address page = (address) _mem_serialize_page; 420 return addr >= page && addr < (page + os::vm_page_size()); 421 } 422 423 static void block_on_serialize_page_trap(); 424 425 // threads 426 427 enum ThreadType { 428 vm_thread, 429 cgc_thread, // Concurrent GC thread 430 pgc_thread, // Parallel GC thread 431 java_thread, 432 compiler_thread, 433 watcher_thread, 434 os_thread 435 }; 436 437 static bool create_thread(Thread* thread, 438 ThreadType thr_type, 439 size_t stack_size = 0); 440 static bool create_main_thread(JavaThread* thread); 441 static bool create_attached_thread(JavaThread* thread); 442 static void pd_start_thread(Thread* thread); 443 static void start_thread(Thread* thread); 444 445 static void initialize_thread(Thread* thr); 446 static void free_thread(OSThread* osthread); 447 448 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit 449 static intx current_thread_id(); 450 static int current_process_id(); 451 static int sleep(Thread* thread, jlong ms, bool interruptable); 452 // Short standalone OS sleep suitable for slow path spin loop. 453 // Ignores Thread.interrupt() (so keep it short). 454 // ms = 0, will sleep for the least amount of time allowed by the OS. 455 static void naked_short_sleep(jlong ms); 456 static void infinite_sleep(); // never returns, use with CAUTION 457 static void naked_yield () ; 458 static OSReturn set_priority(Thread* thread, ThreadPriority priority); 459 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority); 460 461 static void interrupt(Thread* thread); 462 static bool is_interrupted(Thread* thread, bool clear_interrupted); 463 464 static int pd_self_suspend_thread(Thread* thread); 465 466 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp); 467 static frame fetch_frame_from_context(void* ucVoid); 468 469 static ExtendedPC get_thread_pc(Thread *thread); 470 static void breakpoint(); 471 472 static address current_stack_pointer(); 473 static address current_stack_base(); 474 static size_t current_stack_size(); 475 476 static void verify_stack_alignment() PRODUCT_RETURN; 477 478 static int message_box(const char* title, const char* message); 479 static char* do_you_want_to_debug(const char* message); 480 481 // run cmd in a separate process and return its exit code; or -1 on failures 482 static int fork_and_exec(char *cmd); 483 484 // os::exit() is merged with vm_exit() 485 // static void exit(int num); 486 487 // Terminate the VM, but don't exit the process 488 static void shutdown(); 489 490 // Terminate with an error. Default is to generate a core file on platforms 491 // that support such things. This calls shutdown() and then aborts. 492 static void abort(bool dump_core = true); 493 494 // Die immediately, no exit hook, no abort hook, no cleanup. 495 static void die(); 496 497 // File i/o operations 498 static const int default_file_open_flags(); 499 static int open(const char *path, int oflag, int mode); 500 static FILE* open(int fd, const char* mode); 501 static int close(int fd); 502 static jlong lseek(int fd, jlong offset, int whence); 503 static char* native_path(char *path); 504 static int ftruncate(int fd, jlong length); 505 static int fsync(int fd); 506 static int available(int fd, jlong *bytes); 507 508 //File i/o operations 509 510 static size_t read(int fd, void *buf, unsigned int nBytes); 511 static size_t restartable_read(int fd, void *buf, unsigned int nBytes); 512 static size_t write(int fd, const void *buf, unsigned int nBytes); 513 514 // Reading directories. 515 static DIR* opendir(const char* dirname); 516 static int readdir_buf_size(const char *path); 517 static struct dirent* readdir(DIR* dirp, dirent* dbuf); 518 static int closedir(DIR* dirp); 519 520 // Dynamic library extension 521 static const char* dll_file_extension(); 522 523 static const char* get_temp_directory(); 524 static const char* get_current_directory(char *buf, size_t buflen); 525 526 // Builds a platform-specific full library path given a ld path and lib name 527 // Returns true if buffer contains full path to existing file, false otherwise 528 static bool dll_build_name(char* buffer, size_t size, 529 const char* pathname, const char* fname); 530 531 // Symbol lookup, find nearest function name; basically it implements 532 // dladdr() for all platforms. Name of the nearest function is copied 533 // to buf. Distance from its base address is optionally returned as offset. 534 // If function name is not found, buf[0] is set to '\0' and offset is 535 // set to -1 (if offset is non-NULL). 536 static bool dll_address_to_function_name(address addr, char* buf, 537 int buflen, int* offset); 538 539 // Locate DLL/DSO. On success, full path of the library is copied to 540 // buf, and offset is optionally set to be the distance between addr 541 // and the library's base address. On failure, buf[0] is set to '\0' 542 // and offset is set to -1 (if offset is non-NULL). 543 static bool dll_address_to_library_name(address addr, char* buf, 544 int buflen, int* offset); 545 546 // Find out whether the pc is in the static code for jvm.dll/libjvm.so. 547 static bool address_is_in_vm(address addr); 548 549 // Loads .dll/.so and 550 // in case of error it checks if .dll/.so was built for the 551 // same architecture as HotSpot is running on 552 static void* dll_load(const char *name, char *ebuf, int ebuflen); 553 554 // lookup symbol in a shared library 555 static void* dll_lookup(void* handle, const char* name); 556 557 // Unload library 558 static void dll_unload(void *lib); 559 560 // Callback for loaded module information 561 // Input parameters: 562 // char* module_file_name, 563 // address module_base_addr, 564 // address module_top_addr, 565 // void* param 566 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *); 567 568 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param); 569 570 // Return the handle of this process 571 static void* get_default_process_handle(); 572 573 // Check for static linked agent library 574 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], 575 size_t syms_len); 576 577 // Find agent entry point 578 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib, 579 const char *syms[], size_t syms_len); 580 581 // Print out system information; they are called by fatal error handler. 582 // Output format may be different on different platforms. 583 static void print_os_info(outputStream* st); 584 static void print_os_info_brief(outputStream* st); 585 static void print_cpu_info(outputStream* st); 586 static void pd_print_cpu_info(outputStream* st); 587 static void print_memory_info(outputStream* st); 588 static void print_dll_info(outputStream* st); 589 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len); 590 static void print_context(outputStream* st, void* context); 591 static void print_register_info(outputStream* st, void* context); 592 static void print_siginfo(outputStream* st, void* siginfo); 593 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen); 594 static void print_date_and_time(outputStream* st); 595 596 static void print_location(outputStream* st, intptr_t x, bool verbose = false); 597 static size_t lasterror(char *buf, size_t len); 598 static int get_last_error(); 599 600 // Determines whether the calling process is being debugged by a user-mode debugger. 601 static bool is_debugger_attached(); 602 603 // wait for a key press if PauseAtExit is set 604 static void wait_for_keypress_at_exit(void); 605 606 // The following two functions are used by fatal error handler to trace 607 // native (C) frames. They are not part of frame.hpp/frame.cpp because 608 // frame.hpp/cpp assume thread is JavaThread, and also because different 609 // OS/compiler may have different convention or provide different API to 610 // walk C frames. 611 // 612 // We don't attempt to become a debugger, so we only follow frames if that 613 // does not require a lookup in the unwind table, which is part of the binary 614 // file but may be unsafe to read after a fatal error. So on x86, we can 615 // only walk stack if %ebp is used as frame pointer; on ia64, it's not 616 // possible to walk C stack without having the unwind table. 617 static bool is_first_C_frame(frame *fr); 618 static frame get_sender_for_C_frame(frame *fr); 619 620 // return current frame. pc() and sp() are set to NULL on failure. 621 static frame current_frame(); 622 623 static void print_hex_dump(outputStream* st, address start, address end, int unitsize); 624 625 // returns a string to describe the exception/signal; 626 // returns NULL if exception_code is not an OS exception/signal. 627 static const char* exception_name(int exception_code, char* buf, size_t buflen); 628 629 // Returns native Java library, loads if necessary 630 static void* native_java_library(); 631 632 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler) 633 static void jvm_path(char *buf, jint buflen); 634 635 // Returns true if we are running in a headless jre. 636 static bool is_headless_jre(); 637 638 // JNI names 639 static void print_jni_name_prefix_on(outputStream* st, int args_size); 640 static void print_jni_name_suffix_on(outputStream* st, int args_size); 641 642 // Init os specific system properties values 643 static void init_system_properties_values(); 644 645 // IO operations, non-JVM_ version. 646 static int stat(const char* path, struct stat* sbuf); 647 static bool dir_is_empty(const char* path); 648 649 // IO operations on binary files 650 static int create_binary_file(const char* path, bool rewrite_existing); 651 static jlong current_file_offset(int fd); 652 static jlong seek_to_file_offset(int fd, jlong offset); 653 654 // Thread Local Storage 655 static int allocate_thread_local_storage(); 656 static void thread_local_storage_at_put(int index, void* value); 657 static void* thread_local_storage_at(int index); 658 static void free_thread_local_storage(int index); 659 660 // Retrieve native stack frames. 661 // Parameter: 662 // stack: an array to storage stack pointers. 663 // frames: size of above array. 664 // toSkip: number of stack frames to skip at the beginning. 665 // Return: number of stack frames captured. 666 static int get_native_stack(address* stack, int size, int toSkip = 0); 667 668 // General allocation (must be MT-safe) 669 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack); 670 static void* malloc (size_t size, MEMFLAGS flags); 671 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack); 672 static void* realloc (void *memblock, size_t size, MEMFLAGS flag); 673 674 static void free (void *memblock, MEMFLAGS flags = mtNone); 675 static bool check_heap(bool force = false); // verify C heap integrity 676 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup 677 // Like strdup, but exit VM when strdup() returns NULL 678 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal); 679 680 #ifndef PRODUCT 681 static julong num_mallocs; // # of calls to malloc/realloc 682 static julong alloc_bytes; // # of bytes allocated 683 static julong num_frees; // # of calls to free 684 static julong free_bytes; // # of bytes freed 685 #endif 686 687 // SocketInterface (ex HPI SocketInterface ) 688 static int socket(int domain, int type, int protocol); 689 static int socket_close(int fd); 690 static int socket_shutdown(int fd, int howto); 691 static int recv(int fd, char* buf, size_t nBytes, uint flags); 692 static int send(int fd, char* buf, size_t nBytes, uint flags); 693 static int raw_send(int fd, char* buf, size_t nBytes, uint flags); 694 static int timeout(int fd, long timeout); 695 static int listen(int fd, int count); 696 static int connect(int fd, struct sockaddr* him, socklen_t len); 697 static int bind(int fd, struct sockaddr* him, socklen_t len); 698 static int accept(int fd, struct sockaddr* him, socklen_t* len); 699 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags, 700 struct sockaddr* from, socklen_t* fromlen); 701 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len); 702 static int sendto(int fd, char* buf, size_t len, uint flags, 703 struct sockaddr* to, socklen_t tolen); 704 static int socket_available(int fd, jint* pbytes); 705 706 static int get_sock_opt(int fd, int level, int optname, 707 char* optval, socklen_t* optlen); 708 static int set_sock_opt(int fd, int level, int optname, 709 const char* optval, socklen_t optlen); 710 static int get_host_name(char* name, int namelen); 711 712 static struct hostent* get_host_by_name(char* name); 713 714 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal) 715 static void signal_init(); 716 static void signal_init_pd(); 717 static void signal_notify(int signal_number); 718 static void* signal(int signal_number, void* handler); 719 static void signal_raise(int signal_number); 720 static int signal_wait(); 721 static int signal_lookup(); 722 static void* user_handler(); 723 static void terminate_signal_thread(); 724 static int sigexitnum_pd(); 725 726 // random number generation 727 static long random(); // return 32bit pseudorandom number 728 static void init_random(long initval); // initialize random sequence 729 730 // Structured OS Exception support 731 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread); 732 733 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits 734 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize); 735 736 // Get the default path to the core file 737 // Returns the length of the string 738 static int get_core_path(char* buffer, size_t bufferSize); 739 740 // JVMTI & JVM monitoring and management support 741 // The thread_cpu_time() and current_thread_cpu_time() are only 742 // supported if is_thread_cpu_time_supported() returns true. 743 // They are not supported on Solaris T1. 744 745 // Thread CPU Time - return the fast estimate on a platform 746 // On Solaris - call gethrvtime (fast) - user time only 747 // On Linux - fast clock_gettime where available - user+sys 748 // - otherwise: very slow /proc fs - user+sys 749 // On Windows - GetThreadTimes - user+sys 750 static jlong current_thread_cpu_time(); 751 static jlong thread_cpu_time(Thread* t); 752 753 // Thread CPU Time with user_sys_cpu_time parameter. 754 // 755 // If user_sys_cpu_time is true, user+sys time is returned. 756 // Otherwise, only user time is returned 757 static jlong current_thread_cpu_time(bool user_sys_cpu_time); 758 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time); 759 760 // Return a bunch of info about the timers. 761 // Note that the returned info for these two functions may be different 762 // on some platforms 763 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 764 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr); 765 766 static bool is_thread_cpu_time_supported(); 767 768 // System loadavg support. Returns -1 if load average cannot be obtained. 769 static int loadavg(double loadavg[], int nelem); 770 771 // Hook for os specific jvm options that we don't want to abort on seeing 772 static bool obsolete_option(const JavaVMOption *option); 773 774 // Extensions 775 #include "runtime/os_ext.hpp" 776 777 public: 778 class CrashProtectionCallback : public StackObj { 779 public: 780 virtual void call() = 0; 781 }; 782 783 // Platform dependent stuff 784 #ifdef TARGET_OS_FAMILY_linux 785 # include "os_linux.hpp" 786 # include "os_posix.hpp" 787 #endif 788 #ifdef TARGET_OS_FAMILY_solaris 789 # include "os_solaris.hpp" 790 # include "os_posix.hpp" 791 #endif 792 #ifdef TARGET_OS_FAMILY_windows 793 # include "os_windows.hpp" 794 #endif 795 #ifdef TARGET_OS_FAMILY_aix 796 # include "os_aix.hpp" 797 # include "os_posix.hpp" 798 #endif 799 #ifdef TARGET_OS_FAMILY_bsd 800 # include "os_posix.hpp" 801 # include "os_bsd.hpp" 802 #endif 803 #ifdef TARGET_OS_ARCH_linux_x86 804 # include "os_linux_x86.hpp" 805 #endif 806 #ifdef TARGET_OS_ARCH_linux_sparc 807 # include "os_linux_sparc.hpp" 808 #endif 809 #ifdef TARGET_OS_ARCH_linux_zero 810 # include "os_linux_zero.hpp" 811 #endif 812 #ifdef TARGET_OS_ARCH_solaris_x86 813 # include "os_solaris_x86.hpp" 814 #endif 815 #ifdef TARGET_OS_ARCH_solaris_sparc 816 # include "os_solaris_sparc.hpp" 817 #endif 818 #ifdef TARGET_OS_ARCH_windows_x86 819 # include "os_windows_x86.hpp" 820 #endif 821 #ifdef TARGET_OS_ARCH_linux_arm 822 # include "os_linux_arm.hpp" 823 #endif 824 #ifdef TARGET_OS_ARCH_linux_ppc 825 # include "os_linux_ppc.hpp" 826 #endif 827 #ifdef TARGET_OS_ARCH_aix_ppc 828 # include "os_aix_ppc.hpp" 829 #endif 830 #ifdef TARGET_OS_ARCH_bsd_x86 831 # include "os_bsd_x86.hpp" 832 #endif 833 #ifdef TARGET_OS_ARCH_bsd_zero 834 # include "os_bsd_zero.hpp" 835 #endif 836 837 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG 838 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached" 839 #endif 840 841 public: 842 #ifndef PLATFORM_PRINT_NATIVE_STACK 843 // No platform-specific code for printing the native stack. 844 static bool platform_print_native_stack(outputStream* st, void* context, 845 char *buf, int buf_size) { 846 return false; 847 } 848 #endif 849 850 // debugging support (mostly used by debug.cpp but also fatal error handler) 851 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address 852 853 static bool dont_yield(); // when true, JVM_Yield() is nop 854 static void print_statistics(); 855 856 // Thread priority helpers (implemented in OS-specific part) 857 static OSReturn set_native_priority(Thread* thread, int native_prio); 858 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr); 859 static int java_to_os_priority[CriticalPriority + 1]; 860 // Hint to the underlying OS that a task switch would not be good. 861 // Void return because it's a hint and can fail. 862 static void hint_no_preempt(); 863 static const char* native_thread_creation_failed_msg() { 864 return OS_NATIVE_THREAD_CREATION_FAILED_MSG; 865 } 866 867 // Used at creation if requested by the diagnostic flag PauseAtStartup. 868 // Causes the VM to wait until an external stimulus has been applied 869 // (for Unix, that stimulus is a signal, for Windows, an external 870 // ResumeThread call) 871 static void pause(); 872 873 // Builds a platform dependent Agent_OnLoad_<libname> function name 874 // which is used to find statically linked in agents. 875 static char* build_agent_function_name(const char *sym, const char *cname, 876 bool is_absolute_path); 877 878 class SuspendedThreadTaskContext { 879 public: 880 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {} 881 Thread* thread() const { return _thread; } 882 void* ucontext() const { return _ucontext; } 883 private: 884 Thread* _thread; 885 void* _ucontext; 886 }; 887 888 class SuspendedThreadTask { 889 public: 890 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {} 891 virtual ~SuspendedThreadTask() {} 892 void run(); 893 bool is_done() { return _done; } 894 virtual void do_task(const SuspendedThreadTaskContext& context) = 0; 895 protected: 896 private: 897 void internal_do_task(); 898 Thread* _thread; 899 bool _done; 900 }; 901 902 #ifndef TARGET_OS_FAMILY_windows 903 // Suspend/resume support 904 // Protocol: 905 // 906 // a thread starts in SR_RUNNING 907 // 908 // SR_RUNNING can go to 909 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it 910 // SR_SUSPEND_REQUEST can go to 911 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout) 912 // * SR_SUSPENDED if the stopped thread receives the signal and switches state 913 // SR_SUSPENDED can go to 914 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume 915 // SR_WAKEUP_REQUEST can go to 916 // * SR_RUNNING when the stopped thread receives the signal 917 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again) 918 class SuspendResume { 919 public: 920 enum State { 921 SR_RUNNING, 922 SR_SUSPEND_REQUEST, 923 SR_SUSPENDED, 924 SR_WAKEUP_REQUEST 925 }; 926 927 private: 928 volatile State _state; 929 930 private: 931 /* try to switch state from state "from" to state "to" 932 * returns the state set after the method is complete 933 */ 934 State switch_state(State from, State to); 935 936 public: 937 SuspendResume() : _state(SR_RUNNING) { } 938 939 State state() const { return _state; } 940 941 State request_suspend() { 942 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST); 943 } 944 945 State cancel_suspend() { 946 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING); 947 } 948 949 State suspended() { 950 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED); 951 } 952 953 State request_wakeup() { 954 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST); 955 } 956 957 State running() { 958 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING); 959 } 960 961 bool is_running() const { 962 return _state == SR_RUNNING; 963 } 964 965 bool is_suspend_request() const { 966 return _state == SR_SUSPEND_REQUEST; 967 } 968 969 bool is_suspended() const { 970 return _state == SR_SUSPENDED; 971 } 972 }; 973 #endif 974 975 976 protected: 977 static long _rand_seed; // seed for random number generator 978 static int _processor_count; // number of processors 979 980 static char* format_boot_path(const char* format_string, 981 const char* home, 982 int home_len, 983 char fileSep, 984 char pathSep); 985 static bool set_boot_path(char fileSep, char pathSep); 986 static char** split_path(const char* path, int* n); 987 988 }; 989 990 // Note that "PAUSE" is almost always used with synchronization 991 // so arguably we should provide Atomic::SpinPause() instead 992 // of the global SpinPause() with C linkage. 993 // It'd also be eligible for inlining on many platforms. 994 995 extern "C" int SpinPause(); 996 997 #endif // SHARE_VM_RUNTIME_OS_HPP