1 /*
2 * Copyright (c) 1997, 2016, 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 "prims/jvm.h"
30 #include "runtime/extendedPC.hpp"
31 #include "runtime/handles.hpp"
32 #include "utilities/macros.hpp"
33 #ifndef _WINDOWS
34 # include <setjmp.h>
35 #endif
36 #ifdef __APPLE__
37 # include <mach/mach_time.h>
38 #endif
39
40 class AgentLibrary;
41
42 // os defines the interface to operating system; this includes traditional
43 // OS services (time, I/O) as well as other functionality with system-
44 // dependent code.
45
46 typedef void (*dll_func)(...);
47
48 class Thread;
49 class JavaThread;
50 class Event;
51 class DLL;
52 class FileHandle;
53 class NativeCallStack;
54
55 template<class E> class GrowableArray;
56
57 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
58
59 // Platform-independent error return values from OS functions
60 enum OSReturn {
61 OS_OK = 0, // Operation was successful
62 OS_ERR = -1, // Operation failed
63 OS_INTRPT = -2, // Operation was interrupted
64 OS_TIMEOUT = -3, // Operation timed out
65 OS_NOMEM = -5, // Operation failed for lack of memory
66 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
67 };
68
69 enum ThreadPriority { // JLS 20.20.1-3
70 NoPriority = -1, // Initial non-priority value
71 MinPriority = 1, // Minimum priority
72 NormPriority = 5, // Normal (non-daemon) priority
73 NearMaxPriority = 9, // High priority, used for VMThread
74 MaxPriority = 10, // Highest priority, used for WatcherThread
75 // ensures that VMThread doesn't starve profiler
76 CriticalPriority = 11 // Critical thread priority
77 };
78
79 // Executable parameter flag for os::commit_memory() and
80 // os::commit_memory_or_exit().
81 const bool ExecMem = true;
82
83 // Typedef for structured exception handling support
84 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
85
86 class MallocTracker;
87
88 class os: AllStatic {
89 friend class VMStructs;
90 friend class JVMCIVMStructs;
91 friend class MallocTracker;
92 public:
93 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
94
95 private:
96 static OSThread* _starting_thread;
97 static address _polling_page;
98 static volatile int32_t * _mem_serialize_page;
99 static uintptr_t _serialize_page_mask;
100 public:
101 static size_t _page_sizes[page_sizes_max];
102
103 private:
104 static void init_page_sizes(size_t default_page_size) {
105 _page_sizes[0] = default_page_size;
106 _page_sizes[1] = 0; // sentinel
107 }
108
109 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
110 size_t alignment_hint = 0);
111 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
112 static void pd_split_reserved_memory(char *base, size_t size,
113 size_t split, bool realloc);
114 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
115 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
116 bool executable);
117 // Same as pd_commit_memory() that either succeeds or calls
118 // vm_exit_out_of_memory() with the specified mesg.
119 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
120 bool executable, const char* mesg);
121 static void pd_commit_memory_or_exit(char* addr, size_t size,
122 size_t alignment_hint,
123 bool executable, const char* mesg);
124 static bool pd_uncommit_memory(char* addr, size_t bytes);
125 static bool pd_release_memory(char* addr, size_t bytes);
126
127 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
128 char *addr, size_t bytes, bool read_only = false,
129 bool allow_exec = false);
130 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
131 char *addr, size_t bytes, bool read_only,
132 bool allow_exec);
133 static bool pd_unmap_memory(char *addr, size_t bytes);
134 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
135 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
136
137 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
138
139 // Get summary strings for system information in buffer provided
140 static void get_summary_cpu_info(char* buf, size_t buflen);
141 static void get_summary_os_info(char* buf, size_t buflen);
142
143 static void initialize_initial_active_processor_count();
144 public:
145 static void init(void); // Called before command line parsing
146 static void init_before_ergo(void); // Called after command line parsing
147 // before VM ergonomics processing.
148 static jint init_2(void); // Called after command line parsing
149 // and VM ergonomics processing
150 static void init_globals(void) { // Called from init_globals() in init.cpp
151 init_globals_ext();
152 }
153
154 // File names are case-insensitive on windows only
155 // Override me as needed
156 static int file_name_strcmp(const char* s1, const char* s2);
157
158 // unset environment variable
159 static bool unsetenv(const char* name);
160
161 static bool have_special_privileges();
162
163 static jlong javaTimeMillis();
164 static jlong javaTimeNanos();
165 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
166 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
167 static void run_periodic_checks();
168 static bool supports_monotonic_clock();
169
170 // Returns the elapsed time in seconds since the vm started.
171 static double elapsedTime();
172
173 // Returns real time in seconds since an arbitrary point
174 // in the past.
175 static bool getTimesSecs(double* process_real_time,
176 double* process_user_time,
177 double* process_system_time);
178
179 // Interface to the performance counter
180 static jlong elapsed_counter();
181 static jlong elapsed_frequency();
182
183 // The "virtual time" of a thread is the amount of time a thread has
184 // actually run. The first function indicates whether the OS supports
185 // this functionality for the current thread, and if so:
186 // * the second enables vtime tracking (if that is required).
187 // * the third tells whether vtime is enabled.
188 // * the fourth returns the elapsed virtual time for the current
189 // thread.
190 static bool supports_vtime();
191 static bool enable_vtime();
192 static bool vtime_enabled();
193 static double elapsedVTime();
194
195 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
196 // It is MT safe, but not async-safe, as reading time zone
197 // information may require a lock on some platforms.
198 static char* local_time_string(char *buf, size_t buflen);
199 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
200 // Fill in buffer with current local time as an ISO-8601 string.
201 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
202 // Returns buffer, or NULL if it failed.
203 static char* iso8601_time(char* buffer, size_t buffer_length);
204
205 // Interface for detecting multiprocessor system
206 static inline bool is_MP() {
207 // During bootstrap if _processor_count is not yet initialized
208 // we claim to be MP as that is safest. If any platform has a
209 // stub generator that might be triggered in this phase and for
210 // which being declared MP when in fact not, is a problem - then
211 // the bootstrap routine for the stub generator needs to check
212 // the processor count directly and leave the bootstrap routine
213 // in place until called after initialization has ocurred.
214 return (_processor_count != 1) || AssumeMP;
215 }
216 static julong available_memory();
217 static julong physical_memory();
218 static bool has_allocatable_memory_limit(julong* limit);
219 static bool is_server_class_machine();
220
221 // number of CPUs
222 static int processor_count() {
223 return _processor_count;
224 }
225 static void set_processor_count(int count) { _processor_count = count; }
226
227 // Returns the number of CPUs this process is currently allowed to run on.
228 // Note that on some OSes this can change dynamically.
229 static int active_processor_count();
230
231 // At startup the number of active CPUs this process is allowed to run on.
232 // This value does not change dynamically. May be different from active_processor_count().
233 static int initial_active_processor_count() {
234 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
235 return _initial_active_processor_count;
236 }
237
238 // Bind processes to processors.
239 // This is a two step procedure:
240 // first you generate a distribution of processes to processors,
241 // then you bind processes according to that distribution.
242 // Compute a distribution for number of processes to processors.
243 // Stores the processor id's into the distribution array argument.
244 // Returns true if it worked, false if it didn't.
245 static bool distribute_processes(uint length, uint* distribution);
246 // Binds the current process to a processor.
247 // Returns true if it worked, false if it didn't.
248 static bool bind_to_processor(uint processor_id);
249
250 // Give a name to the current thread.
251 static void set_native_thread_name(const char *name);
252
253 // Interface for stack banging (predetect possible stack overflow for
254 // exception processing) There are guard pages, and above that shadow
255 // pages for stack overflow checking.
256 static bool uses_stack_guard_pages();
257 static bool must_commit_stack_guard_pages();
258 static void map_stack_shadow_pages(address sp);
259 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
260
261 // OS interface to Virtual Memory
262
263 // Return the default page size.
264 static int vm_page_size();
265
266 // Returns the page size to use for a region of memory.
267 // region_size / min_pages will always be greater than or equal to the
268 // returned value. The returned value will divide region_size.
269 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
270
271 // Returns the page size to use for a region of memory.
272 // region_size / min_pages will always be greater than or equal to the
273 // returned value. The returned value might not divide region_size.
274 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
275
276 // Return the largest page size that can be used
277 static size_t max_page_size() {
278 // The _page_sizes array is sorted in descending order.
279 return _page_sizes[0];
280 }
281
282 // Methods for tracing page sizes returned by the above method.
283 // The region_{min,max}_size parameters should be the values
284 // passed to page_size_for_region() and page_size should be the result of that
285 // call. The (optional) base and size parameters should come from the
286 // ReservedSpace base() and size() methods.
287 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
288 static void trace_page_sizes(const char* str,
289 const size_t region_min_size,
290 const size_t region_max_size,
291 const size_t page_size,
292 const char* base,
293 const size_t size);
294 static void trace_page_sizes_for_requested_size(const char* str,
295 const size_t requested_size,
296 const size_t page_size,
297 const size_t alignment,
298 const char* base,
299 const size_t size);
300
301 static int vm_allocation_granularity();
302 static char* reserve_memory(size_t bytes, char* addr = 0,
303 size_t alignment_hint = 0);
304 static char* reserve_memory(size_t bytes, char* addr,
305 size_t alignment_hint, MEMFLAGS flags);
306 static char* reserve_memory_aligned(size_t size, size_t alignment);
307 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
308 static void split_reserved_memory(char *base, size_t size,
309 size_t split, bool realloc);
310 static bool commit_memory(char* addr, size_t bytes, bool executable);
311 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
312 bool executable);
313 // Same as commit_memory() that either succeeds or calls
314 // vm_exit_out_of_memory() with the specified mesg.
315 static void commit_memory_or_exit(char* addr, size_t bytes,
316 bool executable, const char* mesg);
317 static void commit_memory_or_exit(char* addr, size_t size,
318 size_t alignment_hint,
319 bool executable, const char* mesg);
320 static bool uncommit_memory(char* addr, size_t bytes);
321 static bool release_memory(char* addr, size_t bytes);
322
323 // Touch memory pages that cover the memory range from start to end (exclusive)
324 // to make the OS back the memory range with actual memory.
325 // Current implementation may not touch the last page if unaligned addresses
326 // are passed.
327 static void pretouch_memory(void* start, void* end);
328
329 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
330 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
331 bool is_committed = true);
332
333 static bool guard_memory(char* addr, size_t bytes);
334 static bool unguard_memory(char* addr, size_t bytes);
335 static bool create_stack_guard_pages(char* addr, size_t bytes);
336 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
337 static bool remove_stack_guard_pages(char* addr, size_t bytes);
338
339 static char* map_memory(int fd, const char* file_name, size_t file_offset,
340 char *addr, size_t bytes, bool read_only = false,
341 bool allow_exec = false);
342 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
343 char *addr, size_t bytes, bool read_only,
344 bool allow_exec);
345 static bool unmap_memory(char *addr, size_t bytes);
346 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
347 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
348
349 // NUMA-specific interface
350 static bool numa_has_static_binding();
351 static bool numa_has_group_homing();
352 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
353 static void numa_make_global(char *addr, size_t bytes);
354 static size_t numa_get_groups_num();
355 static size_t numa_get_leaf_groups(int *ids, size_t size);
356 static bool numa_topology_changed();
357 static int numa_get_group_id();
358
359 // Page manipulation
360 struct page_info {
361 size_t size;
362 int lgrp_id;
363 };
364 static bool get_page_info(char *start, page_info* info);
365 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
366
367 static char* non_memory_address_word();
368 // reserve, commit and pin the entire memory region
369 static char* reserve_memory_special(size_t size, size_t alignment,
370 char* addr, bool executable);
371 static bool release_memory_special(char* addr, size_t bytes);
372 static void large_page_init();
373 static size_t large_page_size();
374 static bool can_commit_large_page_memory();
375 static bool can_execute_large_page_memory();
376
377 // OS interface to polling page
378 static address get_polling_page() { return _polling_page; }
379 static void set_polling_page(address page) { _polling_page = page; }
380 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
381 static void make_polling_page_unreadable();
382 static void make_polling_page_readable();
383
384 // Routines used to serialize the thread state without using membars
385 static void serialize_thread_states();
386
387 // Since we write to the serialize page from every thread, we
388 // want stores to be on unique cache lines whenever possible
389 // in order to minimize CPU cross talk. We pre-compute the
390 // amount to shift the thread* to make this offset unique to
391 // each thread.
392 static int get_serialize_page_shift_count() {
393 return SerializePageShiftCount;
394 }
395
396 static void set_serialize_page_mask(uintptr_t mask) {
397 _serialize_page_mask = mask;
398 }
399
400 static unsigned int get_serialize_page_mask() {
401 return _serialize_page_mask;
402 }
403
404 static void set_memory_serialize_page(address page);
405
406 static address get_memory_serialize_page() {
407 return (address)_mem_serialize_page;
408 }
409
410 static inline void write_memory_serialize_page(JavaThread *thread) {
411 uintptr_t page_offset = ((uintptr_t)thread >>
412 get_serialize_page_shift_count()) &
413 get_serialize_page_mask();
414 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
415 }
416
417 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
418 if (UseMembar) return false;
419 // Previously this function calculated the exact address of this
420 // thread's serialize page, and checked if the faulting address
421 // was equal. However, some platforms mask off faulting addresses
422 // to the page size, so now we just check that the address is
423 // within the page. This makes the thread argument unnecessary,
424 // but we retain the NULL check to preserve existing behavior.
425 if (thread == NULL) return false;
426 address page = (address) _mem_serialize_page;
427 return addr >= page && addr < (page + os::vm_page_size());
428 }
429
430 static void block_on_serialize_page_trap();
431
432 // threads
433
434 enum ThreadType {
435 vm_thread,
436 cgc_thread, // Concurrent GC thread
437 pgc_thread, // Parallel GC thread
438 java_thread,
439 compiler_thread,
440 watcher_thread,
441 os_thread
442 };
443
444 static bool create_thread(Thread* thread,
445 ThreadType thr_type,
446 size_t stack_size = 0);
447 static bool create_main_thread(JavaThread* thread);
448 static bool create_attached_thread(JavaThread* thread);
449 static void pd_start_thread(Thread* thread);
450 static void start_thread(Thread* thread);
451
452 static void initialize_thread(Thread* thr);
453 static void free_thread(OSThread* osthread);
454
455 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
456 static intx current_thread_id();
457 static int current_process_id();
458 static int sleep(Thread* thread, jlong ms, bool interruptable);
459 // Short standalone OS sleep suitable for slow path spin loop.
460 // Ignores Thread.interrupt() (so keep it short).
461 // ms = 0, will sleep for the least amount of time allowed by the OS.
462 static void naked_short_sleep(jlong ms);
463 static void infinite_sleep(); // never returns, use with CAUTION
464 static void naked_yield () ;
465 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
466 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
467
468 static void interrupt(Thread* thread);
469 static bool is_interrupted(Thread* thread, bool clear_interrupted);
470
471 static int pd_self_suspend_thread(Thread* thread);
472
473 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
474 static frame fetch_frame_from_context(const void* ucVoid);
475 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
476
477 static ExtendedPC get_thread_pc(Thread *thread);
478 static void breakpoint();
479 static bool start_debugging(char *buf, int buflen);
480
481 static address current_stack_pointer();
482 static address current_stack_base();
483 static size_t current_stack_size();
484
485 static void verify_stack_alignment() PRODUCT_RETURN;
486
487 static bool message_box(const char* title, const char* message);
488 static char* do_you_want_to_debug(const char* message);
489
490 // run cmd in a separate process and return its exit code; or -1 on failures
491 static int fork_and_exec(char *cmd);
492
493 // Call ::exit() on all platforms but Windows
494 static void exit(int num);
495
496 // Terminate the VM, but don't exit the process
497 static void shutdown();
498
499 // Terminate with an error. Default is to generate a core file on platforms
500 // that support such things. This calls shutdown() and then aborts.
501 static void abort(bool dump_core, void *siginfo, const void *context);
502 static void abort(bool dump_core = true);
503
504 // Die immediately, no exit hook, no abort hook, no cleanup.
505 static void die();
506
507 // File i/o operations
508 static const int default_file_open_flags();
509 static int open(const char *path, int oflag, int mode);
510 static FILE* open(int fd, const char* mode);
511 static int close(int fd);
512 static jlong lseek(int fd, jlong offset, int whence);
513 static char* native_path(char *path);
514 static int ftruncate(int fd, jlong length);
515 static int fsync(int fd);
516 static int available(int fd, jlong *bytes);
517 static int get_fileno(FILE* fp);
518 static void flockfile(FILE* fp);
519 static void funlockfile(FILE* fp);
520
521 static int compare_file_modified_times(const char* file1, const char* file2);
522
523 //File i/o operations
524
525 static size_t read(int fd, void *buf, unsigned int nBytes);
526 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
527 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
528 static size_t write(int fd, const void *buf, unsigned int nBytes);
529
530 // Reading directories.
531 static DIR* opendir(const char* dirname);
532 static int readdir_buf_size(const char *path);
533 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
534 static int closedir(DIR* dirp);
535
536 // Dynamic library extension
537 static const char* dll_file_extension();
538
539 static const char* get_temp_directory();
540 static const char* get_current_directory(char *buf, size_t buflen);
541
542 // Builds a platform-specific full library path given a ld path and lib name
543 // Returns true if buffer contains full path to existing file, false otherwise
544 static bool dll_build_name(char* buffer, size_t size,
545 const char* pathname, const char* fname);
546
547 // Symbol lookup, find nearest function name; basically it implements
548 // dladdr() for all platforms. Name of the nearest function is copied
549 // to buf. Distance from its base address is optionally returned as offset.
550 // If function name is not found, buf[0] is set to '\0' and offset is
551 // set to -1 (if offset is non-NULL).
552 static bool dll_address_to_function_name(address addr, char* buf,
553 int buflen, int* offset,
554 bool demangle = true);
555
556 // Locate DLL/DSO. On success, full path of the library is copied to
557 // buf, and offset is optionally set to be the distance between addr
558 // and the library's base address. On failure, buf[0] is set to '\0'
559 // and offset is set to -1 (if offset is non-NULL).
560 static bool dll_address_to_library_name(address addr, char* buf,
561 int buflen, int* offset);
562
563 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
564 static bool address_is_in_vm(address addr);
565
566 // Loads .dll/.so and
567 // in case of error it checks if .dll/.so was built for the
568 // same architecture as HotSpot is running on
569 static void* dll_load(const char *name, char *ebuf, int ebuflen);
570
571 // lookup symbol in a shared library
572 static void* dll_lookup(void* handle, const char* name);
573
574 // Unload library
575 static void dll_unload(void *lib);
576
577 // Callback for loaded module information
578 // Input parameters:
579 // char* module_file_name,
580 // address module_base_addr,
581 // address module_top_addr,
582 // void* param
583 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
584
585 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
586
587 // Return the handle of this process
588 static void* get_default_process_handle();
589
590 // Check for static linked agent library
591 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
592 size_t syms_len);
593
594 // Find agent entry point
595 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
596 const char *syms[], size_t syms_len);
597
598 // Write to stream
599 static int log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
600
601 // Get host name in buffer provided
602 static bool get_host_name(char* buf, size_t buflen);
603
604 // Print out system information; they are called by fatal error handler.
605 // Output format may be different on different platforms.
606 static void print_os_info(outputStream* st);
607 static void print_os_info_brief(outputStream* st);
608 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
609 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
610 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
611 static void print_memory_info(outputStream* st);
612 static void print_dll_info(outputStream* st);
613 static void print_environment_variables(outputStream* st, const char** env_list);
614 static void print_context(outputStream* st, const void* context);
615 static void print_register_info(outputStream* st, const void* context);
616 static void print_siginfo(outputStream* st, const void* siginfo);
617 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
618 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
619
620 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
621 static size_t lasterror(char *buf, size_t len);
622 static int get_last_error();
623
624 // Replacement for strerror().
625 // Will return the english description of the error (e.g. "File not found", as
626 // suggested in the POSIX standard.
627 // Will return "Unknown error" for an unknown errno value.
628 // Will not attempt to localize the returned string.
629 // Will always return a valid string which is a static constant.
630 // Will not change the value of errno.
631 static const char* strerror(int e);
632
633 // Will return the literalized version of the given errno (e.g. "EINVAL"
634 // for EINVAL).
635 // Will return "Unknown error" for an unknown errno value.
636 // Will always return a valid string which is a static constant.
637 // Will not change the value of errno.
638 static const char* errno_name(int e);
639
640 // Determines whether the calling process is being debugged by a user-mode debugger.
641 static bool is_debugger_attached();
642
643 // wait for a key press if PauseAtExit is set
644 static void wait_for_keypress_at_exit(void);
645
646 // The following two functions are used by fatal error handler to trace
647 // native (C) frames. They are not part of frame.hpp/frame.cpp because
648 // frame.hpp/cpp assume thread is JavaThread, and also because different
649 // OS/compiler may have different convention or provide different API to
650 // walk C frames.
651 //
652 // We don't attempt to become a debugger, so we only follow frames if that
653 // does not require a lookup in the unwind table, which is part of the binary
654 // file but may be unsafe to read after a fatal error. So on x86, we can
655 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
656 // possible to walk C stack without having the unwind table.
657 static bool is_first_C_frame(frame *fr);
658 static frame get_sender_for_C_frame(frame *fr);
659
660 // return current frame. pc() and sp() are set to NULL on failure.
661 static frame current_frame();
662
663 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
664
665 // returns a string to describe the exception/signal;
666 // returns NULL if exception_code is not an OS exception/signal.
667 static const char* exception_name(int exception_code, char* buf, size_t buflen);
668
669 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
670 static int get_signal_number(const char* signal_name);
671
672 // Returns native Java library, loads if necessary
673 static void* native_java_library();
674
675 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
676 static void jvm_path(char *buf, jint buflen);
677
678 // Returns true if we are running in a headless jre.
679 static bool is_headless_jre();
680
681 // JNI names
682 static void print_jni_name_prefix_on(outputStream* st, int args_size);
683 static void print_jni_name_suffix_on(outputStream* st, int args_size);
684
685 // Init os specific system properties values
686 static void init_system_properties_values();
687
688 // IO operations, non-JVM_ version.
689 static int stat(const char* path, struct stat* sbuf);
690 static bool dir_is_empty(const char* path);
691
692 // IO operations on binary files
693 static int create_binary_file(const char* path, bool rewrite_existing);
694 static jlong current_file_offset(int fd);
695 static jlong seek_to_file_offset(int fd, jlong offset);
696
697 // Retrieve native stack frames.
698 // Parameter:
699 // stack: an array to storage stack pointers.
700 // frames: size of above array.
701 // toSkip: number of stack frames to skip at the beginning.
702 // Return: number of stack frames captured.
703 static int get_native_stack(address* stack, int size, int toSkip = 0);
704
705 // General allocation (must be MT-safe)
706 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
707 static void* malloc (size_t size, MEMFLAGS flags);
708 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
709 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
710
711 static void free (void *memblock);
712 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
713 // Like strdup, but exit VM when strdup() returns NULL
714 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
715
716 #ifndef PRODUCT
717 static julong num_mallocs; // # of calls to malloc/realloc
718 static julong alloc_bytes; // # of bytes allocated
719 static julong num_frees; // # of calls to free
720 static julong free_bytes; // # of bytes freed
721 #endif
722
723 // SocketInterface (ex HPI SocketInterface )
724 static int socket(int domain, int type, int protocol);
725 static int socket_close(int fd);
726 static int recv(int fd, char* buf, size_t nBytes, uint flags);
727 static int send(int fd, char* buf, size_t nBytes, uint flags);
728 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
729 static int connect(int fd, struct sockaddr* him, socklen_t len);
730 static struct hostent* get_host_by_name(char* name);
731
732 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
733 static void signal_init();
734 static void signal_init_pd();
735 static void signal_notify(int signal_number);
736 static void* signal(int signal_number, void* handler);
737 static void signal_raise(int signal_number);
738 static int signal_wait();
739 static int signal_lookup();
740 static void* user_handler();
741 static void terminate_signal_thread();
742 static int sigexitnum_pd();
743
744 // random number generation
745 static long random(); // return 32bit pseudorandom number
746 static void init_random(long initval); // initialize random sequence
747
748 // Structured OS Exception support
749 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
750
751 // On Posix compatible OS it will simply check core dump limits while on Windows
752 // it will check if dump file can be created. Check or prepare a core dump to be
753 // taken at a later point in the same thread in os::abort(). Use the caller
754 // provided buffer as a scratch buffer. The status message which will be written
755 // into the error log either is file location or a short error message, depending
756 // on the checking result.
757 static void check_dump_limit(char* buffer, size_t bufferSize);
758
759 // Get the default path to the core file
760 // Returns the length of the string
761 static int get_core_path(char* buffer, size_t bufferSize);
762
763 // JVMTI & JVM monitoring and management support
764 // The thread_cpu_time() and current_thread_cpu_time() are only
765 // supported if is_thread_cpu_time_supported() returns true.
766 // They are not supported on Solaris T1.
767
768 // Thread CPU Time - return the fast estimate on a platform
769 // On Solaris - call gethrvtime (fast) - user time only
770 // On Linux - fast clock_gettime where available - user+sys
771 // - otherwise: very slow /proc fs - user+sys
772 // On Windows - GetThreadTimes - user+sys
773 static jlong current_thread_cpu_time();
774 static jlong thread_cpu_time(Thread* t);
775
776 // Thread CPU Time with user_sys_cpu_time parameter.
777 //
778 // If user_sys_cpu_time is true, user+sys time is returned.
779 // Otherwise, only user time is returned
780 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
781 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
782
783 // Return a bunch of info about the timers.
784 // Note that the returned info for these two functions may be different
785 // on some platforms
786 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
787 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
788
789 static bool is_thread_cpu_time_supported();
790
791 // System loadavg support. Returns -1 if load average cannot be obtained.
792 static int loadavg(double loadavg[], int nelem);
793
794 // Hook for os specific jvm options that we don't want to abort on seeing
795 static bool obsolete_option(const JavaVMOption *option);
796
797 // Amount beyond the callee frame size that we bang the stack.
798 static int extra_bang_size_in_bytes();
799
800 static char** split_path(const char* path, int* n);
801
802 // Extensions
803 #include "runtime/os_ext.hpp"
804
805 public:
806 class CrashProtectionCallback : public StackObj {
807 public:
808 virtual void call() = 0;
809 };
810
811 // Platform dependent stuff
812 #ifndef _WINDOWS
813 # include "os_posix.hpp"
814 #endif
815 #include OS_CPU_HEADER(os)
816 #include OS_HEADER(os)
817
818 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
819 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
820 #endif
821
822 public:
823 #ifndef PLATFORM_PRINT_NATIVE_STACK
824 // No platform-specific code for printing the native stack.
825 static bool platform_print_native_stack(outputStream* st, const void* context,
826 char *buf, int buf_size) {
827 return false;
828 }
829 #endif
830
831 // debugging support (mostly used by debug.cpp but also fatal error handler)
832 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
833
834 static bool dont_yield(); // when true, JVM_Yield() is nop
835 static void print_statistics();
836
837 // Thread priority helpers (implemented in OS-specific part)
838 static OSReturn set_native_priority(Thread* thread, int native_prio);
839 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
840 static int java_to_os_priority[CriticalPriority + 1];
841 // Hint to the underlying OS that a task switch would not be good.
842 // Void return because it's a hint and can fail.
843 static void hint_no_preempt();
844 static const char* native_thread_creation_failed_msg() {
845 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
846 }
847
848 // Used at creation if requested by the diagnostic flag PauseAtStartup.
849 // Causes the VM to wait until an external stimulus has been applied
850 // (for Unix, that stimulus is a signal, for Windows, an external
851 // ResumeThread call)
852 static void pause();
853
854 // Builds a platform dependent Agent_OnLoad_<libname> function name
855 // which is used to find statically linked in agents.
856 static char* build_agent_function_name(const char *sym, const char *cname,
857 bool is_absolute_path);
858
859 class SuspendedThreadTaskContext {
860 public:
861 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
862 Thread* thread() const { return _thread; }
863 void* ucontext() const { return _ucontext; }
864 private:
865 Thread* _thread;
866 void* _ucontext;
867 };
868
869 class SuspendedThreadTask {
870 public:
871 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
872 virtual ~SuspendedThreadTask() {}
873 void run();
874 bool is_done() { return _done; }
875 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
876 protected:
877 private:
878 void internal_do_task();
879 Thread* _thread;
880 bool _done;
881 };
882
883 #ifndef _WINDOWS
884 // Suspend/resume support
885 // Protocol:
886 //
887 // a thread starts in SR_RUNNING
888 //
889 // SR_RUNNING can go to
890 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
891 // SR_SUSPEND_REQUEST can go to
892 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
893 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
894 // SR_SUSPENDED can go to
895 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
896 // SR_WAKEUP_REQUEST can go to
897 // * SR_RUNNING when the stopped thread receives the signal
898 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
899 class SuspendResume {
900 public:
901 enum State {
902 SR_RUNNING,
903 SR_SUSPEND_REQUEST,
904 SR_SUSPENDED,
905 SR_WAKEUP_REQUEST
906 };
907
908 private:
909 volatile State _state;
910
911 private:
912 /* try to switch state from state "from" to state "to"
913 * returns the state set after the method is complete
914 */
915 State switch_state(State from, State to);
916
917 public:
918 SuspendResume() : _state(SR_RUNNING) { }
919
920 State state() const { return _state; }
921
922 State request_suspend() {
923 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
924 }
925
926 State cancel_suspend() {
927 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
928 }
929
930 State suspended() {
931 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
932 }
933
934 State request_wakeup() {
935 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
936 }
937
938 State running() {
939 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
940 }
941
942 bool is_running() const {
943 return _state == SR_RUNNING;
944 }
945
946 bool is_suspend_request() const {
947 return _state == SR_SUSPEND_REQUEST;
948 }
949
950 bool is_suspended() const {
951 return _state == SR_SUSPENDED;
952 }
953 };
954 #endif // !WINDOWS
955
956
957 protected:
958 static long _rand_seed; // seed for random number generator
959 static int _processor_count; // number of processors
960 static int _initial_active_processor_count; // number of active processors during initialization.
961
962 static char* format_boot_path(const char* format_string,
963 const char* home,
964 int home_len,
965 char fileSep,
966 char pathSep);
967 static bool set_boot_path(char fileSep, char pathSep);
968
969 };
970
971 // Note that "PAUSE" is almost always used with synchronization
972 // so arguably we should provide Atomic::SpinPause() instead
973 // of the global SpinPause() with C linkage.
974 // It'd also be eligible for inlining on many platforms.
975
976 extern "C" int SpinPause();
977
978 #endif // SHARE_VM_RUNTIME_OS_HPP