1 /*
2 * Copyright (c) 1997, 2015, 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 // unset environment variable
168 static bool unsetenv(const char* name);
169
170 static bool have_special_privileges();
171
172 static jlong javaTimeMillis();
173 static jlong javaTimeNanos();
174 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
175 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
176 static void run_periodic_checks();
177 static bool supports_monotonic_clock();
178
179 // Returns the elapsed time in seconds since the vm started.
180 static double elapsedTime();
181
182 // Returns real time in seconds since an arbitrary point
183 // in the past.
184 static bool getTimesSecs(double* process_real_time,
185 double* process_user_time,
186 double* process_system_time);
187
188 // Interface to the performance counter
189 static jlong elapsed_counter();
190 static jlong elapsed_frequency();
191
192 // The "virtual time" of a thread is the amount of time a thread has
193 // actually run. The first function indicates whether the OS supports
194 // this functionality for the current thread, and if so:
195 // * the second enables vtime tracking (if that is required).
196 // * the third tells whether vtime is enabled.
197 // * the fourth returns the elapsed virtual time for the current
198 // thread.
199 static bool supports_vtime();
200 static bool enable_vtime();
201 static bool vtime_enabled();
202 static double elapsedVTime();
203
204 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
205 // It is MT safe, but not async-safe, as reading time zone
206 // information may require a lock on some platforms.
207 static char* local_time_string(char *buf, size_t buflen);
208 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
209 // Fill in buffer with current local time as an ISO-8601 string.
210 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
211 // Returns buffer, or NULL if it failed.
212 static char* iso8601_time(char* buffer, size_t buffer_length);
213
214 // Interface for detecting multiprocessor system
215 static inline bool is_MP() {
216 // During bootstrap if _processor_count is not yet initialized
217 // we claim to be MP as that is safest. If any platform has a
218 // stub generator that might be triggered in this phase and for
219 // which being declared MP when in fact not, is a problem - then
220 // the bootstrap routine for the stub generator needs to check
221 // the processor count directly and leave the bootstrap routine
222 // in place until called after initialization has ocurred.
223 return (_processor_count != 1) || AssumeMP;
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 // Returns the page size to use for a region of memory.
269 // region_size / min_pages will always be greater than or equal to the
270 // returned value. The returned value will divide region_size.
271 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
272
273 // Returns the page size to use for a region of memory.
274 // region_size / min_pages will always be greater than or equal to the
275 // returned value. The returned value might not divide region_size.
276 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
277
278 // Return the largest page size that can be used
279 static size_t max_page_size() {
280 // The _page_sizes array is sorted in descending order.
281 return _page_sizes[0];
282 }
283
284 // Methods for tracing page sizes returned by the above method; enabled by
285 // TracePageSizes. The region_{min,max}_size parameters should be the values
286 // passed to page_size_for_region() and page_size should be the result of that
287 // call. The (optional) base and size parameters should come from the
288 // ReservedSpace base() and size() methods.
289 static void trace_page_sizes(const char* str, const size_t* page_sizes,
290 int count) PRODUCT_RETURN;
291 static void trace_page_sizes(const char* str, const size_t region_min_size,
292 const size_t region_max_size,
293 const size_t page_size,
294 const char* base = NULL,
295 const size_t size = 0) PRODUCT_RETURN;
296
297 static int vm_allocation_granularity();
298 static char* reserve_memory(size_t bytes, char* addr = 0,
299 size_t alignment_hint = 0);
300 static char* reserve_memory(size_t bytes, char* addr,
301 size_t alignment_hint, MEMFLAGS flags);
302 static char* reserve_memory_aligned(size_t size, size_t alignment);
303 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
304 static void split_reserved_memory(char *base, size_t size,
305 size_t split, bool realloc);
306 static bool commit_memory(char* addr, size_t bytes, bool executable);
307 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
308 bool executable);
309 // Same as commit_memory() that either succeeds or calls
310 // vm_exit_out_of_memory() with the specified mesg.
311 static void commit_memory_or_exit(char* addr, size_t bytes,
312 bool executable, const char* mesg);
313 static void commit_memory_or_exit(char* addr, size_t size,
314 size_t alignment_hint,
315 bool executable, const char* mesg);
316 static bool uncommit_memory(char* addr, size_t bytes);
317 static bool release_memory(char* addr, size_t bytes);
318
319 // Touch memory pages that cover the memory range from start to end (exclusive)
320 // to make the OS back the memory range with actual memory.
321 // Current implementation may not touch the last page if unaligned addresses
322 // are passed.
323 static void pretouch_memory(char* start, char* end);
324
325 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
326 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
327 bool is_committed = true);
328
329 static bool guard_memory(char* addr, size_t bytes);
330 static bool unguard_memory(char* addr, size_t bytes);
331 static bool create_stack_guard_pages(char* addr, size_t bytes);
332 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
333 static bool remove_stack_guard_pages(char* addr, size_t bytes);
334
335 static char* map_memory(int fd, const char* file_name, size_t file_offset,
336 char *addr, size_t bytes, bool read_only = false,
337 bool allow_exec = false);
338 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
339 char *addr, size_t bytes, bool read_only,
340 bool allow_exec);
341 static bool unmap_memory(char *addr, size_t bytes);
342 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
343 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
344
345 // NUMA-specific interface
346 static bool numa_has_static_binding();
347 static bool numa_has_group_homing();
348 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
349 static void numa_make_global(char *addr, size_t bytes);
350 static size_t numa_get_groups_num();
351 static size_t numa_get_leaf_groups(int *ids, size_t size);
352 static bool numa_topology_changed();
353 static int numa_get_group_id();
354
355 // Page manipulation
356 struct page_info {
357 size_t size;
358 int lgrp_id;
359 };
360 static bool get_page_info(char *start, page_info* info);
361 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
362
363 static char* non_memory_address_word();
364 // reserve, commit and pin the entire memory region
365 static char* reserve_memory_special(size_t size, size_t alignment,
366 char* addr, bool executable);
367 static bool release_memory_special(char* addr, size_t bytes);
368 static void large_page_init();
369 static size_t large_page_size();
370 static bool can_commit_large_page_memory();
371 static bool can_execute_large_page_memory();
372
373 // OS interface to polling page
374 static address get_polling_page() { return _polling_page; }
375 static void set_polling_page(address page) { _polling_page = page; }
376 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
377 static void make_polling_page_unreadable();
378 static void make_polling_page_readable();
379
380 // Routines used to serialize the thread state without using membars
381 static void serialize_thread_states();
382
383 // Since we write to the serialize page from every thread, we
384 // want stores to be on unique cache lines whenever possible
385 // in order to minimize CPU cross talk. We pre-compute the
386 // amount to shift the thread* to make this offset unique to
387 // each thread.
388 static int get_serialize_page_shift_count() {
389 return SerializePageShiftCount;
390 }
391
392 static void set_serialize_page_mask(uintptr_t mask) {
393 _serialize_page_mask = mask;
394 }
395
396 static unsigned int get_serialize_page_mask() {
397 return _serialize_page_mask;
398 }
399
400 static void set_memory_serialize_page(address page);
401
402 static address get_memory_serialize_page() {
403 return (address)_mem_serialize_page;
404 }
405
406 static inline void write_memory_serialize_page(JavaThread *thread) {
407 uintptr_t page_offset = ((uintptr_t)thread >>
408 get_serialize_page_shift_count()) &
409 get_serialize_page_mask();
410 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
411 }
412
413 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
414 if (UseMembar) return false;
415 // Previously this function calculated the exact address of this
416 // thread's serialize page, and checked if the faulting address
417 // was equal. However, some platforms mask off faulting addresses
418 // to the page size, so now we just check that the address is
419 // within the page. This makes the thread argument unnecessary,
420 // but we retain the NULL check to preserve existing behavior.
421 if (thread == NULL) return false;
422 address page = (address) _mem_serialize_page;
423 return addr >= page && addr < (page + os::vm_page_size());
424 }
425
426 static void block_on_serialize_page_trap();
427
428 // threads
429
430 enum ThreadType {
431 vm_thread,
432 cgc_thread, // Concurrent GC thread
433 pgc_thread, // Parallel GC thread
434 java_thread,
435 compiler_thread,
436 watcher_thread,
437 os_thread
438 };
439
440 static bool create_thread(Thread* thread,
441 ThreadType thr_type,
442 size_t stack_size = 0);
443 static bool create_main_thread(JavaThread* thread);
444 static bool create_attached_thread(JavaThread* thread);
445 static void pd_start_thread(Thread* thread);
446 static void start_thread(Thread* thread);
447
448 static void initialize_thread(Thread* thr);
449 static void free_thread(OSThread* osthread);
450
451 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
452 static intx current_thread_id();
453 static int current_process_id();
454 static int sleep(Thread* thread, jlong ms, bool interruptable);
455 // Short standalone OS sleep suitable for slow path spin loop.
456 // Ignores Thread.interrupt() (so keep it short).
457 // ms = 0, will sleep for the least amount of time allowed by the OS.
458 static void naked_short_sleep(jlong ms);
459 static void infinite_sleep(); // never returns, use with CAUTION
460 static void naked_yield () ;
461 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
462 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
463
464 static void interrupt(Thread* thread);
465 static bool is_interrupted(Thread* thread, bool clear_interrupted);
466
467 static int pd_self_suspend_thread(Thread* thread);
468
469 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
470 static frame fetch_frame_from_context(void* ucVoid);
471
472 static ExtendedPC get_thread_pc(Thread *thread);
473 static void breakpoint();
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 int message_box(const char* title, const char* message);
482 static char* do_you_want_to_debug(const char* message);
483
484 // run cmd in a separate process and return its exit code; or -1 on failures
485 static int fork_and_exec(char *cmd);
486
487 // Call ::exit() on all platforms but Windows
488 static void exit(int num);
489
490 // Terminate the VM, but don't exit the process
491 static void shutdown();
492
493 // Terminate with an error. Default is to generate a core file on platforms
494 // that support such things. This calls shutdown() and then aborts.
495 static void abort(bool dump_core = true);
496
497 // Die immediately, no exit hook, no abort hook, no cleanup.
498 static void die();
499
500 // File i/o operations
501 static const int default_file_open_flags();
502 static int open(const char *path, int oflag, int mode);
503 static FILE* open(int fd, const char* mode);
504 static int close(int fd);
505 static jlong lseek(int fd, jlong offset, int whence);
506 static char* native_path(char *path);
507 static int ftruncate(int fd, jlong length);
508 static int fsync(int fd);
509 static int available(int fd, jlong *bytes);
510
511 //File i/o operations
512
513 static size_t read(int fd, void *buf, unsigned int nBytes);
514 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
515 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
516 static size_t write(int fd, const void *buf, unsigned int nBytes);
517
518 // Reading directories.
519 static DIR* opendir(const char* dirname);
520 static int readdir_buf_size(const char *path);
521 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
522 static int closedir(DIR* dirp);
523
524 // Dynamic library extension
525 static const char* dll_file_extension();
526
527 static const char* get_temp_directory();
528 static const char* get_current_directory(char *buf, size_t buflen);
529
530 // Builds a platform-specific full library path given a ld path and lib name
531 // Returns true if buffer contains full path to existing file, false otherwise
532 static bool dll_build_name(char* buffer, size_t size,
533 const char* pathname, const char* fname);
534
535 // Symbol lookup, find nearest function name; basically it implements
536 // dladdr() for all platforms. Name of the nearest function is copied
537 // to buf. Distance from its base address is optionally returned as offset.
538 // If function name is not found, buf[0] is set to '\0' and offset is
539 // set to -1 (if offset is non-NULL).
540 static bool dll_address_to_function_name(address addr, char* buf,
541 int buflen, int* offset);
542
543 // Locate DLL/DSO. On success, full path of the library is copied to
544 // buf, and offset is optionally set to be the distance between addr
545 // and the library's base address. On failure, buf[0] is set to '\0'
546 // and offset is set to -1 (if offset is non-NULL).
547 static bool dll_address_to_library_name(address addr, char* buf,
548 int buflen, int* offset);
549
550 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
551 static bool address_is_in_vm(address addr);
552
553 // Loads .dll/.so and
554 // in case of error it checks if .dll/.so was built for the
555 // same architecture as HotSpot is running on
556 static void* dll_load(const char *name, char *ebuf, int ebuflen);
557
558 // lookup symbol in a shared library
559 static void* dll_lookup(void* handle, const char* name);
560
561 // Unload library
562 static void dll_unload(void *lib);
563
564 // Callback for loaded module information
565 // Input parameters:
566 // char* module_file_name,
567 // address module_base_addr,
568 // address module_top_addr,
569 // void* param
570 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
571
572 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
573
574 // Return the handle of this process
575 static void* get_default_process_handle();
576
577 // Check for static linked agent library
578 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
579 size_t syms_len);
580
581 // Find agent entry point
582 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
583 const char *syms[], size_t syms_len);
584
585 // Print out system information; they are called by fatal error handler.
586 // Output format may be different on different platforms.
587 static void print_os_info(outputStream* st);
588 static void print_os_info_brief(outputStream* st);
589 static void print_cpu_info(outputStream* st);
590 static void pd_print_cpu_info(outputStream* st);
591 static void print_memory_info(outputStream* st);
592 static void print_dll_info(outputStream* st);
593 static void print_environment_variables(outputStream* st, const char** env_list);
594 static void print_context(outputStream* st, void* context);
595 static void print_register_info(outputStream* st, void* context);
596 static void print_siginfo(outputStream* st, void* siginfo);
597 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
598 static void print_date_and_time(outputStream* st);
599
600 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
601 static size_t lasterror(char *buf, size_t len);
602 static int get_last_error();
603
604 // Determines whether the calling process is being debugged by a user-mode debugger.
605 static bool is_debugger_attached();
606
607 // wait for a key press if PauseAtExit is set
608 static void wait_for_keypress_at_exit(void);
609
610 // The following two functions are used by fatal error handler to trace
611 // native (C) frames. They are not part of frame.hpp/frame.cpp because
612 // frame.hpp/cpp assume thread is JavaThread, and also because different
613 // OS/compiler may have different convention or provide different API to
614 // walk C frames.
615 //
616 // We don't attempt to become a debugger, so we only follow frames if that
617 // does not require a lookup in the unwind table, which is part of the binary
618 // file but may be unsafe to read after a fatal error. So on x86, we can
619 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
620 // possible to walk C stack without having the unwind table.
621 static bool is_first_C_frame(frame *fr);
622 static frame get_sender_for_C_frame(frame *fr);
623
624 // return current frame. pc() and sp() are set to NULL on failure.
625 static frame current_frame();
626
627 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
628
629 // returns a string to describe the exception/signal;
630 // returns NULL if exception_code is not an OS exception/signal.
631 static const char* exception_name(int exception_code, char* buf, size_t buflen);
632
633 // Returns native Java library, loads if necessary
634 static void* native_java_library();
635
636 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
637 static void jvm_path(char *buf, jint buflen);
638
639 // Returns true if we are running in a headless jre.
640 static bool is_headless_jre();
641
642 // JNI names
643 static void print_jni_name_prefix_on(outputStream* st, int args_size);
644 static void print_jni_name_suffix_on(outputStream* st, int args_size);
645
646 // Init os specific system properties values
647 static void init_system_properties_values();
648
649 // IO operations, non-JVM_ version.
650 static int stat(const char* path, struct stat* sbuf);
651 static bool dir_is_empty(const char* path);
652
653 // IO operations on binary files
654 static int create_binary_file(const char* path, bool rewrite_existing);
655 static jlong current_file_offset(int fd);
656 static jlong seek_to_file_offset(int fd, jlong offset);
657
658 // Thread Local Storage
659 static int allocate_thread_local_storage();
660 static void thread_local_storage_at_put(int index, void* value);
661 static void* thread_local_storage_at(int index);
662 static void free_thread_local_storage(int index);
663
664 // Retrieve native stack frames.
665 // Parameter:
666 // stack: an array to storage stack pointers.
667 // frames: size of above array.
668 // toSkip: number of stack frames to skip at the beginning.
669 // Return: number of stack frames captured.
670 static int get_native_stack(address* stack, int size, int toSkip = 0);
671
672 // General allocation (must be MT-safe)
673 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
674 static void* malloc (size_t size, MEMFLAGS flags);
675 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
676 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
677
678 static void free (void *memblock);
679 static bool check_heap(bool force = false); // verify C heap integrity
680 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
681 // Like strdup, but exit VM when strdup() returns NULL
682 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
683
684 #ifndef PRODUCT
685 static julong num_mallocs; // # of calls to malloc/realloc
686 static julong alloc_bytes; // # of bytes allocated
687 static julong num_frees; // # of calls to free
688 static julong free_bytes; // # of bytes freed
689 #endif
690
691 // SocketInterface (ex HPI SocketInterface )
692 static int socket(int domain, int type, int protocol);
693 static int socket_close(int fd);
694 static int recv(int fd, char* buf, size_t nBytes, uint flags);
695 static int send(int fd, char* buf, size_t nBytes, uint flags);
696 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
697 static int connect(int fd, struct sockaddr* him, socklen_t len);
698 static struct hostent* get_host_by_name(char* name);
699
700 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
701 static void signal_init();
702 static void signal_init_pd();
703 static void signal_notify(int signal_number);
704 static void* signal(int signal_number, void* handler);
705 static void signal_raise(int signal_number);
706 static int signal_wait();
707 static int signal_lookup();
708 static void* user_handler();
709 static void terminate_signal_thread();
710 static int sigexitnum_pd();
711
712 // random number generation
713 static long random(); // return 32bit pseudorandom number
714 static void init_random(long initval); // initialize random sequence
715
716 // Structured OS Exception support
717 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
718
719 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
720 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
721
722 // Get the default path to the core file
723 // Returns the length of the string
724 static int get_core_path(char* buffer, size_t bufferSize);
725
726 // JVMTI & JVM monitoring and management support
727 // The thread_cpu_time() and current_thread_cpu_time() are only
728 // supported if is_thread_cpu_time_supported() returns true.
729 // They are not supported on Solaris T1.
730
731 // Thread CPU Time - return the fast estimate on a platform
732 // On Solaris - call gethrvtime (fast) - user time only
733 // On Linux - fast clock_gettime where available - user+sys
734 // - otherwise: very slow /proc fs - user+sys
735 // On Windows - GetThreadTimes - user+sys
736 static jlong current_thread_cpu_time();
737 static jlong thread_cpu_time(Thread* t);
738
739 // Thread CPU Time with user_sys_cpu_time parameter.
740 //
741 // If user_sys_cpu_time is true, user+sys time is returned.
742 // Otherwise, only user time is returned
743 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
744 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
745
746 // Return a bunch of info about the timers.
747 // Note that the returned info for these two functions may be different
748 // on some platforms
749 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
750 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
751
752 static bool is_thread_cpu_time_supported();
753
754 // System loadavg support. Returns -1 if load average cannot be obtained.
755 static int loadavg(double loadavg[], int nelem);
756
757 // Hook for os specific jvm options that we don't want to abort on seeing
758 static bool obsolete_option(const JavaVMOption *option);
759
760 // Amount beyond the callee frame size that we bang the stack.
761 static int extra_bang_size_in_bytes();
762
763 // Extensions
764 #include "runtime/os_ext.hpp"
765
766 public:
767 class CrashProtectionCallback : public StackObj {
768 public:
769 virtual void call() = 0;
770 };
771
772 // Platform dependent stuff
773 #ifdef TARGET_OS_FAMILY_linux
774 # include "os_linux.hpp"
775 # include "os_posix.hpp"
776 #endif
777 #ifdef TARGET_OS_FAMILY_solaris
778 # include "os_solaris.hpp"
779 # include "os_posix.hpp"
780 #endif
781 #ifdef TARGET_OS_FAMILY_windows
782 # include "os_windows.hpp"
783 #endif
784 #ifdef TARGET_OS_FAMILY_aix
785 # include "os_aix.hpp"
786 # include "os_posix.hpp"
787 #endif
788 #ifdef TARGET_OS_FAMILY_bsd
789 # include "os_posix.hpp"
790 # include "os_bsd.hpp"
791 #endif
792 #ifdef TARGET_OS_ARCH_linux_x86
793 # include "os_linux_x86.hpp"
794 #endif
795 #ifdef TARGET_OS_ARCH_linux_sparc
796 # include "os_linux_sparc.hpp"
797 #endif
798 #ifdef TARGET_OS_ARCH_linux_zero
799 # include "os_linux_zero.hpp"
800 #endif
801 #ifdef TARGET_OS_ARCH_solaris_x86
802 # include "os_solaris_x86.hpp"
803 #endif
804 #ifdef TARGET_OS_ARCH_solaris_sparc
805 # include "os_solaris_sparc.hpp"
806 #endif
807 #ifdef TARGET_OS_ARCH_windows_x86
808 # include "os_windows_x86.hpp"
809 #endif
810 #ifdef TARGET_OS_ARCH_linux_arm
811 # include "os_linux_arm.hpp"
812 #endif
813 #ifdef TARGET_OS_ARCH_linux_ppc
814 # include "os_linux_ppc.hpp"
815 #endif
816 #ifdef TARGET_OS_ARCH_aix_ppc
817 # include "os_aix_ppc.hpp"
818 #endif
819 #ifdef TARGET_OS_ARCH_bsd_x86
820 # include "os_bsd_x86.hpp"
821 #endif
822 #ifdef TARGET_OS_ARCH_bsd_zero
823 # include "os_bsd_zero.hpp"
824 #endif
825
826 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
827 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
828 #endif
829
830 public:
831 #ifndef PLATFORM_PRINT_NATIVE_STACK
832 // No platform-specific code for printing the native stack.
833 static bool platform_print_native_stack(outputStream* st, void* context,
834 char *buf, int buf_size) {
835 return false;
836 }
837 #endif
838
839 // debugging support (mostly used by debug.cpp but also fatal error handler)
840 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
841
842 static bool dont_yield(); // when true, JVM_Yield() is nop
843 static void print_statistics();
844
845 // Thread priority helpers (implemented in OS-specific part)
846 static OSReturn set_native_priority(Thread* thread, int native_prio);
847 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
848 static int java_to_os_priority[CriticalPriority + 1];
849 // Hint to the underlying OS that a task switch would not be good.
850 // Void return because it's a hint and can fail.
851 static void hint_no_preempt();
852 static const char* native_thread_creation_failed_msg() {
853 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
854 }
855
856 // Used at creation if requested by the diagnostic flag PauseAtStartup.
857 // Causes the VM to wait until an external stimulus has been applied
858 // (for Unix, that stimulus is a signal, for Windows, an external
859 // ResumeThread call)
860 static void pause();
861
862 // Builds a platform dependent Agent_OnLoad_<libname> function name
863 // which is used to find statically linked in agents.
864 static char* build_agent_function_name(const char *sym, const char *cname,
865 bool is_absolute_path);
866
867 class SuspendedThreadTaskContext {
868 public:
869 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
870 Thread* thread() const { return _thread; }
871 void* ucontext() const { return _ucontext; }
872 private:
873 Thread* _thread;
874 void* _ucontext;
875 };
876
877 class SuspendedThreadTask {
878 public:
879 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
880 virtual ~SuspendedThreadTask() {}
881 void run();
882 bool is_done() { return _done; }
883 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
884 protected:
885 private:
886 void internal_do_task();
887 Thread* _thread;
888 bool _done;
889 };
890
891 #ifndef TARGET_OS_FAMILY_windows
892 // Suspend/resume support
893 // Protocol:
894 //
895 // a thread starts in SR_RUNNING
896 //
897 // SR_RUNNING can go to
898 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
899 // SR_SUSPEND_REQUEST can go to
900 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
901 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
902 // SR_SUSPENDED can go to
903 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
904 // SR_WAKEUP_REQUEST can go to
905 // * SR_RUNNING when the stopped thread receives the signal
906 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
907 class SuspendResume {
908 public:
909 enum State {
910 SR_RUNNING,
911 SR_SUSPEND_REQUEST,
912 SR_SUSPENDED,
913 SR_WAKEUP_REQUEST
914 };
915
916 private:
917 volatile State _state;
918
919 private:
920 /* try to switch state from state "from" to state "to"
921 * returns the state set after the method is complete
922 */
923 State switch_state(State from, State to);
924
925 public:
926 SuspendResume() : _state(SR_RUNNING) { }
927
928 State state() const { return _state; }
929
930 State request_suspend() {
931 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
932 }
933
934 State cancel_suspend() {
935 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
936 }
937
938 State suspended() {
939 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
940 }
941
942 State request_wakeup() {
943 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
944 }
945
946 State running() {
947 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
948 }
949
950 bool is_running() const {
951 return _state == SR_RUNNING;
952 }
953
954 bool is_suspend_request() const {
955 return _state == SR_SUSPEND_REQUEST;
956 }
957
958 bool is_suspended() const {
959 return _state == SR_SUSPENDED;
960 }
961 };
962 #endif
963
964
965 protected:
966 static long _rand_seed; // seed for random number generator
967 static int _processor_count; // number of processors
968
969 static char* format_boot_path(const char* format_string,
970 const char* home,
971 int home_len,
972 char fileSep,
973 char pathSep);
974 static bool set_boot_path(char fileSep, char pathSep);
975 static char** split_path(const char* path, int* n);
976
977 };
978
979 // Note that "PAUSE" is almost always used with synchronization
980 // so arguably we should provide Atomic::SpinPause() instead
981 // of the global SpinPause() with C linkage.
982 // It'd also be eligible for inlining on many platforms.
983
984 extern "C" int SpinPause();
985
986 #endif // SHARE_VM_RUNTIME_OS_HPP