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/atomic.hpp"
30 #include "runtime/extendedPC.hpp"
31 #include "runtime/handles.hpp"
32 #include "utilities/top.hpp"
33 #ifdef TARGET_OS_FAMILY_linux
34 # include "jvm_linux.h"
35 # include <setjmp.h>
36 #endif
37 #ifdef TARGET_OS_FAMILY_solaris
38 # include "jvm_solaris.h"
39 # include <setjmp.h>
40 #endif
41 #ifdef TARGET_OS_FAMILY_windows
42 # include "jvm_windows.h"
43 #endif
44 #ifdef TARGET_OS_FAMILY_aix
45 # include "jvm_aix.h"
46 # include <setjmp.h>
47 #endif
48 #ifdef TARGET_OS_FAMILY_bsd
49 # include "jvm_bsd.h"
50 # include <setjmp.h>
51 # ifdef __APPLE__
52 # include <mach/mach_time.h>
53 # endif
54 #endif
55
56 class AgentLibrary;
57
58 // os defines the interface to operating system; this includes traditional
59 // OS services (time, I/O) as well as other functionality with system-
60 // dependent code.
61
62 typedef void (*dll_func)(...);
63
64 class Thread;
65 class JavaThread;
66 class Event;
67 class DLL;
68 class FileHandle;
69 class NativeCallStack;
70
71 template<class E> class GrowableArray;
72
73 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
74
75 // Platform-independent error return values from OS functions
76 enum OSReturn {
77 OS_OK = 0, // Operation was successful
78 OS_ERR = -1, // Operation failed
79 OS_INTRPT = -2, // Operation was interrupted
80 OS_TIMEOUT = -3, // Operation timed out
81 OS_NOMEM = -5, // Operation failed for lack of memory
82 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
83 };
84
85 enum ThreadPriority { // JLS 20.20.1-3
86 NoPriority = -1, // Initial non-priority value
87 MinPriority = 1, // Minimum priority
88 NormPriority = 5, // Normal (non-daemon) priority
89 NearMaxPriority = 9, // High priority, used for VMThread
90 MaxPriority = 10, // Highest priority, used for WatcherThread
91 // ensures that VMThread doesn't starve profiler
92 CriticalPriority = 11 // Critical thread priority
93 };
94
95 // Executable parameter flag for os::commit_memory() and
96 // os::commit_memory_or_exit().
97 const bool ExecMem = true;
98
99 // Typedef for structured exception handling support
100 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
101
102 class MallocTracker;
103
104 class os: AllStatic {
105 friend class VMStructs;
106 friend class MallocTracker;
107 public:
108 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
109
110 private:
111 static OSThread* _starting_thread;
112 static address _polling_page;
113 static volatile int32_t * _mem_serialize_page;
114 static uintptr_t _serialize_page_mask;
115 public:
116 static size_t _page_sizes[page_sizes_max];
117
118 private:
119 static void init_page_sizes(size_t default_page_size) {
120 _page_sizes[0] = default_page_size;
121 _page_sizes[1] = 0; // sentinel
122 }
123
124 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
125 size_t alignment_hint = 0);
126 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
127 static void pd_split_reserved_memory(char *base, size_t size,
128 size_t split, bool realloc);
129 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
130 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
131 bool executable);
132 // Same as pd_commit_memory() that either succeeds or calls
133 // vm_exit_out_of_memory() with the specified mesg.
134 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
135 bool executable, const char* mesg);
136 static void pd_commit_memory_or_exit(char* addr, size_t size,
137 size_t alignment_hint,
138 bool executable, const char* mesg);
139 static bool pd_uncommit_memory(char* addr, size_t bytes);
140 static bool pd_release_memory(char* addr, size_t bytes);
141
142 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
143 char *addr, size_t bytes, bool read_only = false,
144 bool allow_exec = false);
145 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
146 char *addr, size_t bytes, bool read_only,
147 bool allow_exec);
148 static bool pd_unmap_memory(char *addr, size_t bytes);
149 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
150 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
151
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
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 // Return the page size to use for a region of memory. The min_pages argument
269 // is a hint intended to limit fragmentation; it says the returned page size
270 // should be <= region_max_size / min_pages. Because min_pages is a hint,
271 // this routine may return a size larger than region_max_size / min_pages.
272 //
273 // The current implementation ignores min_pages if a larger page size is an
274 // exact multiple of both region_min_size and region_max_size. This allows
275 // larger pages to be used when doing so would not cause fragmentation; in
276 // particular, a single page can be used when region_min_size ==
277 // region_max_size == a supported page size.
278 static size_t page_size_for_region(size_t region_min_size,
279 size_t region_max_size,
280 uint min_pages);
281 // Return the largest page size that can be used
282 static size_t max_page_size() {
283 // The _page_sizes array is sorted in descending order.
284 return _page_sizes[0];
285 }
286
287 // Methods for tracing page sizes returned by the above method; enabled by
288 // TracePageSizes. The region_{min,max}_size parameters should be the values
289 // passed to page_size_for_region() and page_size should be the result of that
290 // call. The (optional) base and size parameters should come from the
291 // ReservedSpace base() and size() methods.
292 static void trace_page_sizes(const char* str, const size_t* page_sizes,
293 int count) PRODUCT_RETURN;
294 static void trace_page_sizes(const char* str, const size_t region_min_size,
295 const size_t region_max_size,
296 const size_t page_size,
297 const char* base = NULL,
298 const size_t size = 0) PRODUCT_RETURN;
299
300 static int vm_allocation_granularity();
301 static char* reserve_memory(size_t bytes, char* addr = 0,
302 size_t alignment_hint = 0);
303 static char* reserve_memory(size_t bytes, char* addr,
304 size_t alignment_hint, MEMFLAGS flags);
305 static char* reserve_memory_aligned(size_t size, size_t alignment);
306 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
307 static void split_reserved_memory(char *base, size_t size,
308 size_t split, bool realloc);
309 static bool commit_memory(char* addr, size_t bytes, bool executable);
310 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
311 bool executable);
312 // Same as commit_memory() that either succeeds or calls
313 // vm_exit_out_of_memory() with the specified mesg.
314 static void commit_memory_or_exit(char* addr, size_t bytes,
315 bool executable, const char* mesg);
316 static void commit_memory_or_exit(char* addr, size_t size,
317 size_t alignment_hint,
318 bool executable, const char* mesg);
319 static bool uncommit_memory(char* addr, size_t bytes);
320 static bool release_memory(char* addr, size_t bytes);
321
322 // Touch memory pages that cover the memory range from start to end (exclusive)
323 // to make the OS back the memory range with actual memory.
324 // Current implementation may not touch the last page if unaligned addresses
325 // are passed.
326 static void pretouch_memory(char* start, char* end);
327
328 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
329 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
330 bool is_committed = true);
331
332 static bool guard_memory(char* addr, size_t bytes);
333 static bool unguard_memory(char* addr, size_t bytes);
334 static bool create_stack_guard_pages(char* addr, size_t bytes);
335 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
336 static bool remove_stack_guard_pages(char* addr, size_t bytes);
337
338 static char* map_memory(int fd, const char* file_name, size_t file_offset,
339 char *addr, size_t bytes, bool read_only = false,
340 bool allow_exec = false);
341 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
342 char *addr, size_t bytes, bool read_only,
343 bool allow_exec);
344 static bool unmap_memory(char *addr, size_t bytes);
345 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
346 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
347
348 // NUMA-specific interface
349 static bool numa_has_static_binding();
350 static bool numa_has_group_homing();
351 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
352 static void numa_make_global(char *addr, size_t bytes);
353 static size_t numa_get_groups_num();
354 static size_t numa_get_leaf_groups(int *ids, size_t size);
355 static bool numa_topology_changed();
356 static int numa_get_group_id();
357
358 // Page manipulation
359 struct page_info {
360 size_t size;
361 int lgrp_id;
362 };
363 static bool get_page_info(char *start, page_info* info);
364 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
365
366 static char* non_memory_address_word();
367 // reserve, commit and pin the entire memory region
368 static char* reserve_memory_special(size_t size, size_t alignment,
369 char* addr, bool executable);
370 static bool release_memory_special(char* addr, size_t bytes);
371 static void large_page_init();
372 static size_t large_page_size();
373 static bool can_commit_large_page_memory();
374 static bool can_execute_large_page_memory();
375
376 // OS interface to polling page
377 static address get_polling_page() { return _polling_page; }
378 static void set_polling_page(address page) { _polling_page = page; }
379 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
380 static void make_polling_page_unreadable();
381 static void make_polling_page_readable();
382
383 // Routines used to serialize the thread state without using membars
384 static void serialize_thread_states();
385
386 // Since we write to the serialize page from every thread, we
387 // want stores to be on unique cache lines whenever possible
388 // in order to minimize CPU cross talk. We pre-compute the
389 // amount to shift the thread* to make this offset unique to
390 // each thread.
391 static int get_serialize_page_shift_count() {
392 return SerializePageShiftCount;
393 }
394
395 static void set_serialize_page_mask(uintptr_t mask) {
396 _serialize_page_mask = mask;
397 }
398
399 static unsigned int get_serialize_page_mask() {
400 return _serialize_page_mask;
401 }
402
403 static void set_memory_serialize_page(address page);
404
405 static address get_memory_serialize_page() {
406 return (address)_mem_serialize_page;
407 }
408
409 static inline void write_memory_serialize_page(JavaThread *thread) {
410 uintptr_t page_offset = ((uintptr_t)thread >>
411 get_serialize_page_shift_count()) &
412 get_serialize_page_mask();
413 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
414 }
415
416 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
417 if (UseMembar) return false;
418 // Previously this function calculated the exact address of this
419 // thread's serialize page, and checked if the faulting address
420 // was equal. However, some platforms mask off faulting addresses
421 // to the page size, so now we just check that the address is
422 // within the page. This makes the thread argument unnecessary,
423 // but we retain the NULL check to preserve existing behaviour.
424 if (thread == NULL) return false;
425 address page = (address) _mem_serialize_page;
426 return addr >= page && addr < (page + os::vm_page_size());
427 }
428
429 static void block_on_serialize_page_trap();
430
431 // threads
432
433 enum ThreadType {
434 vm_thread,
435 cgc_thread, // Concurrent GC thread
436 pgc_thread, // Parallel GC thread
437 java_thread,
438 compiler_thread,
439 watcher_thread,
440 os_thread
441 };
442
443 static bool create_thread(Thread* thread,
444 ThreadType thr_type,
445 size_t stack_size = 0);
446 static bool create_main_thread(JavaThread* thread);
447 static bool create_attached_thread(JavaThread* thread);
448 static void pd_start_thread(Thread* thread);
449 static void start_thread(Thread* thread);
450
451 static void initialize_thread(Thread* thr);
452 static void free_thread(OSThread* osthread);
453
454 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
455 static intx current_thread_id();
456 static int current_process_id();
457 static int sleep(Thread* thread, jlong ms, bool interruptable);
458 // Short standalone OS sleep suitable for slow path spin loop.
459 // Ignores Thread.interrupt() (so keep it short).
460 // ms = 0, will sleep for the least amount of time allowed by the OS.
461 static void naked_short_sleep(jlong ms);
462 static void infinite_sleep(); // never returns, use with CAUTION
463 static void yield(); // Yields to all threads with same priority
464 enum YieldResult {
465 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
466 YIELD_NONEREADY = 0, // No other runnable/ready threads.
467 // platform-specific yield return immediately
468 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
469 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
470 // yield that can be used in lieu of blocking.
471 } ;
472 static YieldResult NakedYield () ;
473 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
474 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
475 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
476 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
477
478 static void interrupt(Thread* thread);
479 static bool is_interrupted(Thread* thread, bool clear_interrupted);
480
481 static int pd_self_suspend_thread(Thread* thread);
482
483 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
484 static frame fetch_frame_from_context(void* ucVoid);
485
486 static ExtendedPC get_thread_pc(Thread *thread);
487 static void breakpoint();
488
489 static address current_stack_pointer();
490 static address current_stack_base();
491 static size_t current_stack_size();
492
493 static void verify_stack_alignment() PRODUCT_RETURN;
494
495 static int message_box(const char* title, const char* message);
496 static char* do_you_want_to_debug(const char* message);
497
498 // run cmd in a separate process and return its exit code; or -1 on failures
499 static int fork_and_exec(char *cmd);
500
501 // os::exit() is merged with vm_exit()
502 // static void exit(int num);
503
504 // Terminate the VM, but don't exit the process
505 static void shutdown();
506
507 // Terminate with an error. Default is to generate a core file on platforms
508 // that support such things. This calls shutdown() and then aborts.
509 static void abort(bool dump_core = true);
510
511 // Die immediately, no exit hook, no abort hook, no cleanup.
512 static void die();
513
514 // File i/o operations
515 static const int default_file_open_flags();
516 static int open(const char *path, int oflag, int mode);
517 static FILE* open(int fd, const char* mode);
518 static int close(int fd);
519 static jlong lseek(int fd, jlong offset, int whence);
520 static char* native_path(char *path);
521 static int ftruncate(int fd, jlong length);
522 static int fsync(int fd);
523 static int available(int fd, jlong *bytes);
524
525 //File i/o operations
526
527 static size_t read(int fd, void *buf, unsigned int nBytes);
528 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
529 static size_t write(int fd, const void *buf, unsigned int nBytes);
530
531 // Reading directories.
532 static DIR* opendir(const char* dirname);
533 static int readdir_buf_size(const char *path);
534 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
535 static int closedir(DIR* dirp);
536
537 // Dynamic library extension
538 static const char* dll_file_extension();
539
540 static const char* get_temp_directory();
541 static const char* get_current_directory(char *buf, size_t buflen);
542
543 // Builds a platform-specific full library path given a ld path and lib name
544 // Returns true if buffer contains full path to existing file, false otherwise
545 static bool dll_build_name(char* buffer, size_t size,
546 const char* pathname, const char* fname);
547
548 // Symbol lookup, find nearest function name; basically it implements
549 // dladdr() for all platforms. Name of the nearest function is copied
550 // to buf. Distance from its base address is optionally returned as offset.
551 // If function name is not found, buf[0] is set to '\0' and offset is
552 // set to -1 (if offset is non-NULL).
553 static bool dll_address_to_function_name(address addr, char* buf,
554 int buflen, int* offset);
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 // Return the handle of this process
578 static void* get_default_process_handle();
579
580 // Check for static linked agent library
581 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
582 size_t syms_len);
583
584 // Find agent entry point
585 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
586 const char *syms[], size_t syms_len);
587
588 // Print out system information; they are called by fatal error handler.
589 // Output format may be different on different platforms.
590 static void print_os_info(outputStream* st);
591 static void print_os_info_brief(outputStream* st);
592 static void print_cpu_info(outputStream* st);
593 static void pd_print_cpu_info(outputStream* st);
594 static void print_memory_info(outputStream* st);
595 static void print_dll_info(outputStream* st);
596 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
597 static void print_context(outputStream* st, void* context);
598 static void print_register_info(outputStream* st, void* context);
599 static void print_siginfo(outputStream* st, void* siginfo);
600 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
601 static void print_date_and_time(outputStream* st);
602
603 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
604 static size_t lasterror(char *buf, size_t len);
605 static int get_last_error();
606
607 // Determines whether the calling process is being debugged by a user-mode debugger.
608 static bool is_debugger_attached();
609
610 // wait for a key press if PauseAtExit is set
611 static void wait_for_keypress_at_exit(void);
612
613 // The following two functions are used by fatal error handler to trace
614 // native (C) frames. They are not part of frame.hpp/frame.cpp because
615 // frame.hpp/cpp assume thread is JavaThread, and also because different
616 // OS/compiler may have different convention or provide different API to
617 // walk C frames.
618 //
619 // We don't attempt to become a debugger, so we only follow frames if that
620 // does not require a lookup in the unwind table, which is part of the binary
621 // file but may be unsafe to read after a fatal error. So on x86, we can
622 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
623 // possible to walk C stack without having the unwind table.
624 static bool is_first_C_frame(frame *fr);
625 static frame get_sender_for_C_frame(frame *fr);
626
627 // return current frame. pc() and sp() are set to NULL on failure.
628 static frame current_frame();
629
630 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
631
632 // returns a string to describe the exception/signal;
633 // returns NULL if exception_code is not an OS exception/signal.
634 static const char* exception_name(int exception_code, char* buf, size_t buflen);
635
636 // Returns native Java library, loads if necessary
637 static void* native_java_library();
638
639 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
640 static void jvm_path(char *buf, jint buflen);
641
642 // Returns true if we are running in a headless jre.
643 static bool is_headless_jre();
644
645 // JNI names
646 static void print_jni_name_prefix_on(outputStream* st, int args_size);
647 static void print_jni_name_suffix_on(outputStream* st, int args_size);
648
649 // File conventions
650 static const char* file_separator();
651 static const char* line_separator();
652 static const char* path_separator();
653
654 // Init os specific system properties values
655 static void init_system_properties_values();
656
657 // IO operations, non-JVM_ version.
658 static int stat(const char* path, struct stat* sbuf);
659 static bool dir_is_empty(const char* path);
660
661 // IO operations on binary files
662 static int create_binary_file(const char* path, bool rewrite_existing);
663 static jlong current_file_offset(int fd);
664 static jlong seek_to_file_offset(int fd, jlong offset);
665
666 // Thread Local Storage
667 static int allocate_thread_local_storage();
668 static void thread_local_storage_at_put(int index, void* value);
669 static void* thread_local_storage_at(int index);
670 static void free_thread_local_storage(int index);
671
672 // Retrieve native stack frames.
673 // Parameter:
674 // stack: an array to storage stack pointers.
675 // frames: size of above array.
676 // toSkip: number of stack frames to skip at the beginning.
677 // Return: number of stack frames captured.
678 static int get_native_stack(address* stack, int size, int toSkip = 0);
679
680 // General allocation (must be MT-safe)
681 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
682 static void* malloc (size_t size, MEMFLAGS flags);
683 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
684 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
685
686 static void free (void *memblock, MEMFLAGS flags = mtNone);
687 static bool check_heap(bool force = false); // verify C heap integrity
688 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
689
690 #ifndef PRODUCT
691 static julong num_mallocs; // # of calls to malloc/realloc
692 static julong alloc_bytes; // # of bytes allocated
693 static julong num_frees; // # of calls to free
694 static julong free_bytes; // # of bytes freed
695 #endif
696
697 // SocketInterface (ex HPI SocketInterface )
698 static int socket(int domain, int type, int protocol);
699 static int socket_close(int fd);
700 static int socket_shutdown(int fd, int howto);
701 static int recv(int fd, char* buf, size_t nBytes, uint flags);
702 static int send(int fd, char* buf, size_t nBytes, uint flags);
703 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
704 static int timeout(int fd, long timeout);
705 static int listen(int fd, int count);
706 static int connect(int fd, struct sockaddr* him, socklen_t len);
707 static int bind(int fd, struct sockaddr* him, socklen_t len);
708 static int accept(int fd, struct sockaddr* him, socklen_t* len);
709 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
710 struct sockaddr* from, socklen_t* fromlen);
711 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
712 static int sendto(int fd, char* buf, size_t len, uint flags,
713 struct sockaddr* to, socklen_t tolen);
714 static int socket_available(int fd, jint* pbytes);
715
716 static int get_sock_opt(int fd, int level, int optname,
717 char* optval, socklen_t* optlen);
718 static int set_sock_opt(int fd, int level, int optname,
719 const char* optval, socklen_t optlen);
720 static int get_host_name(char* name, int namelen);
721
722 static struct hostent* get_host_by_name(char* name);
723
724 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
725 static void signal_init();
726 static void signal_init_pd();
727 static void signal_notify(int signal_number);
728 static void* signal(int signal_number, void* handler);
729 static void signal_raise(int signal_number);
730 static int signal_wait();
731 static int signal_lookup();
732 static void* user_handler();
733 static void terminate_signal_thread();
734 static int sigexitnum_pd();
735
736 // random number generation
737 static long random(); // return 32bit pseudorandom number
738 static void init_random(long initval); // initialize random sequence
739
740 // Structured OS Exception support
741 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
742
743 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
744 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
745
746 // Get the default path to the core file
747 // Returns the length of the string
748 static int get_core_path(char* buffer, size_t bufferSize);
749
750 // JVMTI & JVM monitoring and management support
751 // The thread_cpu_time() and current_thread_cpu_time() are only
752 // supported if is_thread_cpu_time_supported() returns true.
753 // They are not supported on Solaris T1.
754
755 // Thread CPU Time - return the fast estimate on a platform
756 // On Solaris - call gethrvtime (fast) - user time only
757 // On Linux - fast clock_gettime where available - user+sys
758 // - otherwise: very slow /proc fs - user+sys
759 // On Windows - GetThreadTimes - user+sys
760 static jlong current_thread_cpu_time();
761 static jlong thread_cpu_time(Thread* t);
762
763 // Thread CPU Time with user_sys_cpu_time parameter.
764 //
765 // If user_sys_cpu_time is true, user+sys time is returned.
766 // Otherwise, only user time is returned
767 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
768 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
769
770 // Return a bunch of info about the timers.
771 // Note that the returned info for these two functions may be different
772 // on some platforms
773 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
774 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
775
776 static bool is_thread_cpu_time_supported();
777
778 // System loadavg support. Returns -1 if load average cannot be obtained.
779 static int loadavg(double loadavg[], int nelem);
780
781 // Hook for os specific jvm options that we don't want to abort on seeing
782 static bool obsolete_option(const JavaVMOption *option);
783
784 // Extensions
785 #include "runtime/os_ext.hpp"
786
787 public:
788 class CrashProtectionCallback : public StackObj {
789 public:
790 virtual void call() = 0;
791 };
792
793 // Platform dependent stuff
794 #ifdef TARGET_OS_FAMILY_linux
795 # include "os_linux.hpp"
796 # include "os_posix.hpp"
797 #endif
798 #ifdef TARGET_OS_FAMILY_solaris
799 # include "os_solaris.hpp"
800 # include "os_posix.hpp"
801 #endif
802 #ifdef TARGET_OS_FAMILY_windows
803 # include "os_windows.hpp"
804 #endif
805 #ifdef TARGET_OS_FAMILY_aix
806 # include "os_aix.hpp"
807 # include "os_posix.hpp"
808 #endif
809 #ifdef TARGET_OS_FAMILY_bsd
810 # include "os_posix.hpp"
811 # include "os_bsd.hpp"
812 #endif
813 #ifdef TARGET_OS_ARCH_linux_x86
814 # include "os_linux_x86.hpp"
815 #endif
816 #ifdef TARGET_OS_ARCH_linux_sparc
817 # include "os_linux_sparc.hpp"
818 #endif
819 #ifdef TARGET_OS_ARCH_linux_zero
820 # include "os_linux_zero.hpp"
821 #endif
822 #ifdef TARGET_OS_ARCH_solaris_x86
823 # include "os_solaris_x86.hpp"
824 #endif
825 #ifdef TARGET_OS_ARCH_solaris_sparc
826 # include "os_solaris_sparc.hpp"
827 #endif
828 #ifdef TARGET_OS_ARCH_windows_x86
829 # include "os_windows_x86.hpp"
830 #endif
831 #ifdef TARGET_OS_ARCH_linux_arm
832 # include "os_linux_arm.hpp"
833 #endif
834 #ifdef TARGET_OS_ARCH_linux_ppc
835 # include "os_linux_ppc.hpp"
836 #endif
837 #ifdef TARGET_OS_ARCH_aix_ppc
838 # include "os_aix_ppc.hpp"
839 #endif
840 #ifdef TARGET_OS_ARCH_bsd_x86
841 # include "os_bsd_x86.hpp"
842 #endif
843 #ifdef TARGET_OS_ARCH_bsd_zero
844 # include "os_bsd_zero.hpp"
845 #endif
846
847 public:
848 #ifndef PLATFORM_PRINT_NATIVE_STACK
849 // No platform-specific code for printing the native stack.
850 static bool platform_print_native_stack(outputStream* st, void* context,
851 char *buf, int buf_size) {
852 return false;
853 }
854 #endif
855
856 // debugging support (mostly used by debug.cpp but also fatal error handler)
857 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
858
859 static bool dont_yield(); // when true, JVM_Yield() is nop
860 static void print_statistics();
861
862 // Thread priority helpers (implemented in OS-specific part)
863 static OSReturn set_native_priority(Thread* thread, int native_prio);
864 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
865 static int java_to_os_priority[CriticalPriority + 1];
866 // Hint to the underlying OS that a task switch would not be good.
867 // Void return because it's a hint and can fail.
868 static void hint_no_preempt();
869
870 // Used at creation if requested by the diagnostic flag PauseAtStartup.
871 // Causes the VM to wait until an external stimulus has been applied
872 // (for Unix, that stimulus is a signal, for Windows, an external
873 // ResumeThread call)
874 static void pause();
875
876 // Builds a platform dependent Agent_OnLoad_<libname> function name
877 // which is used to find statically linked in agents.
878 static char* build_agent_function_name(const char *sym, const char *cname,
879 bool is_absolute_path);
880
881 class SuspendedThreadTaskContext {
882 public:
883 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
884 Thread* thread() const { return _thread; }
885 void* ucontext() const { return _ucontext; }
886 private:
887 Thread* _thread;
888 void* _ucontext;
889 };
890
891 class SuspendedThreadTask {
892 public:
893 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
894 virtual ~SuspendedThreadTask() {}
895 void run();
896 bool is_done() { return _done; }
897 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
898 protected:
899 private:
900 void internal_do_task();
901 Thread* _thread;
902 bool _done;
903 };
904
905 #ifndef TARGET_OS_FAMILY_windows
906 // Suspend/resume support
907 // Protocol:
908 //
909 // a thread starts in SR_RUNNING
910 //
911 // SR_RUNNING can go to
912 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
913 // SR_SUSPEND_REQUEST can go to
914 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
915 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
916 // SR_SUSPENDED can go to
917 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
918 // SR_WAKEUP_REQUEST can go to
919 // * SR_RUNNING when the stopped thread receives the signal
920 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
921 class SuspendResume {
922 public:
923 enum State {
924 SR_RUNNING,
925 SR_SUSPEND_REQUEST,
926 SR_SUSPENDED,
927 SR_WAKEUP_REQUEST
928 };
929
930 private:
931 volatile State _state;
932
933 private:
934 /* try to switch state from state "from" to state "to"
935 * returns the state set after the method is complete
936 */
937 State switch_state(State from, State to);
938
939 public:
940 SuspendResume() : _state(SR_RUNNING) { }
941
942 State state() const { return _state; }
943
944 State request_suspend() {
945 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
946 }
947
948 State cancel_suspend() {
949 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
950 }
951
952 State suspended() {
953 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
954 }
955
956 State request_wakeup() {
957 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
958 }
959
960 State running() {
961 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
962 }
963
964 bool is_running() const {
965 return _state == SR_RUNNING;
966 }
967
968 bool is_suspend_request() const {
969 return _state == SR_SUSPEND_REQUEST;
970 }
971
972 bool is_suspended() const {
973 return _state == SR_SUSPENDED;
974 }
975 };
976 #endif
977
978
979 protected:
980 static long _rand_seed; // seed for random number generator
981 static int _processor_count; // number of processors
982
983 static char* format_boot_path(const char* format_string,
984 const char* home,
985 int home_len,
986 char fileSep,
987 char pathSep);
988 static bool set_boot_path(char fileSep, char pathSep);
989 static char** split_path(const char* path, int* n);
990
991 };
992
993 // Note that "PAUSE" is almost always used with synchronization
994 // so arguably we should provide Atomic::SpinPause() instead
995 // of the global SpinPause() with C linkage.
996 // It'd also be eligible for inlining on many platforms.
997
998 extern "C" int SpinPause();
999
1000 #endif // SHARE_VM_RUNTIME_OS_HPP