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