1 /*
2 * Copyright (c) 1997, 2011, 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 #endif
36 #ifdef TARGET_OS_FAMILY_solaris
37 # include "jvm_solaris.h"
38 #endif
39 #ifdef TARGET_OS_FAMILY_windows
40 # include "jvm_windows.h"
41 #endif
42 #ifdef TARGET_OS_FAMILY_bsd
43 # include "jvm_bsd.h"
44 #endif
45
46 // os defines the interface to operating system; this includes traditional
47 // OS services (time, I/O) as well as other functionality with system-
48 // dependent code.
49
50 typedef void (*dll_func)(...);
51
52 class Thread;
53 class JavaThread;
54 class Event;
55 class DLL;
56 class FileHandle;
57 template<class E> class GrowableArray;
58
59 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
60
61 // Platform-independent error return values from OS functions
62 enum OSReturn {
63 OS_OK = 0, // Operation was successful
64 OS_ERR = -1, // Operation failed
65 OS_INTRPT = -2, // Operation was interrupted
66 OS_TIMEOUT = -3, // Operation timed out
67 OS_NOMEM = -5, // Operation failed for lack of memory
68 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
69 };
70
71 enum ThreadPriority { // JLS 20.20.1-3
72 NoPriority = -1, // Initial non-priority value
73 MinPriority = 1, // Minimum priority
74 NormPriority = 5, // Normal (non-daemon) priority
75 NearMaxPriority = 9, // High priority, used for VMThread
76 MaxPriority = 10, // Highest priority, used for WatcherThread
77 // ensures that VMThread doesn't starve profiler
78 CriticalPriority = 11 // Critical thread priority
79 };
80
81 // Typedef for structured exception handling support
82 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
83
84 class os: AllStatic {
85 public:
86 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
87
88 private:
89 static OSThread* _starting_thread;
90 static address _polling_page;
91 static volatile int32_t * _mem_serialize_page;
92 static uintptr_t _serialize_page_mask;
93 public:
94 static size_t _page_sizes[page_sizes_max];
95
96 private:
97 static void init_page_sizes(size_t default_page_size) {
98 _page_sizes[0] = default_page_size;
99 _page_sizes[1] = 0; // sentinel
100 }
101
102 public:
103 static void init(void); // Called before command line parsing
104 static jint init_2(void); // Called after command line parsing
105 static void init_globals(void) { // Called from init_globals() in init.cpp
106 init_globals_ext();
107 }
108 static void init_3(void); // Called at the end of vm init
109
110 // File names are case-insensitive on windows only
111 // Override me as needed
112 static int file_name_strcmp(const char* s1, const char* s2);
113
114 static bool getenv(const char* name, char* buffer, int len);
115 static bool have_special_privileges();
116
117 static jlong javaTimeMillis();
118 static jlong javaTimeNanos();
119 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
120 static void run_periodic_checks();
121
122
123 // Returns the elapsed time in seconds since the vm started.
124 static double elapsedTime();
125
126 // Returns real time in seconds since an arbitrary point
127 // in the past.
128 static bool getTimesSecs(double* process_real_time,
129 double* process_user_time,
130 double* process_system_time);
131
132 // Interface to the performance counter
133 static jlong elapsed_counter();
134 static jlong elapsed_frequency();
135
136 // The "virtual time" of a thread is the amount of time a thread has
137 // actually run. The first function indicates whether the OS supports
138 // this functionality for the current thread, and if so:
139 // * the second enables vtime tracking (if that is required).
140 // * the third tells whether vtime is enabled.
141 // * the fourth returns the elapsed virtual time for the current
142 // thread.
143 static bool supports_vtime();
144 static bool enable_vtime();
145 static bool vtime_enabled();
146 static double elapsedVTime();
147
148 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
149 // It is MT safe, but not async-safe, as reading time zone
150 // information may require a lock on some platforms.
151 static char* local_time_string(char *buf, size_t buflen);
152 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
153 // Fill in buffer with current local time as an ISO-8601 string.
154 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
155 // Returns buffer, or NULL if it failed.
156 static char* iso8601_time(char* buffer, size_t buffer_length);
157
158 // Interface for detecting multiprocessor system
159 static inline bool is_MP() {
160 assert(_processor_count > 0, "invalid processor count");
161 return _processor_count > 1;
162 }
163 static julong available_memory();
164 static julong physical_memory();
165 static julong allocatable_physical_memory(julong size);
166 static bool is_server_class_machine();
167
168 // number of CPUs
169 static int processor_count() {
170 return _processor_count;
171 }
172 static void set_processor_count(int count) { _processor_count = count; }
173
174 // Returns the number of CPUs this process is currently allowed to run on.
175 // Note that on some OSes this can change dynamically.
176 static int active_processor_count();
177
178 // Bind processes to processors.
179 // This is a two step procedure:
180 // first you generate a distribution of processes to processors,
181 // then you bind processes according to that distribution.
182 // Compute a distribution for number of processes to processors.
183 // Stores the processor id's into the distribution array argument.
184 // Returns true if it worked, false if it didn't.
185 static bool distribute_processes(uint length, uint* distribution);
186 // Binds the current process to a processor.
187 // Returns true if it worked, false if it didn't.
188 static bool bind_to_processor(uint processor_id);
189
190 // Give a name to the current thread.
191 static void set_native_thread_name(const char *name);
192
193 // Interface for stack banging (predetect possible stack overflow for
194 // exception processing) There are guard pages, and above that shadow
195 // pages for stack overflow checking.
196 static bool uses_stack_guard_pages();
197 static bool allocate_stack_guard_pages();
198 static void bang_stack_shadow_pages();
199 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
200
201 // OS interface to Virtual Memory
202
203 // Return the default page size.
204 static int vm_page_size();
205
206 // Return the page size to use for a region of memory. The min_pages argument
207 // is a hint intended to limit fragmentation; it says the returned page size
208 // should be <= region_max_size / min_pages. Because min_pages is a hint,
209 // this routine may return a size larger than region_max_size / min_pages.
210 //
211 // The current implementation ignores min_pages if a larger page size is an
212 // exact multiple of both region_min_size and region_max_size. This allows
213 // larger pages to be used when doing so would not cause fragmentation; in
214 // particular, a single page can be used when region_min_size ==
215 // region_max_size == a supported page size.
216 static size_t page_size_for_region(size_t region_min_size,
217 size_t region_max_size,
218 uint min_pages);
219
220 // Methods for tracing page sizes returned by the above method; enabled by
221 // TracePageSizes. The region_{min,max}_size parameters should be the values
222 // passed to page_size_for_region() and page_size should be the result of that
223 // call. The (optional) base and size parameters should come from the
224 // ReservedSpace base() and size() methods.
225 static void trace_page_sizes(const char* str, const size_t* page_sizes,
226 int count) PRODUCT_RETURN;
227 static void trace_page_sizes(const char* str, const size_t region_min_size,
228 const size_t region_max_size,
229 const size_t page_size,
230 const char* base = NULL,
231 const size_t size = 0) PRODUCT_RETURN;
232
233 static int vm_allocation_granularity();
234 static char* reserve_memory(size_t bytes, char* addr = 0,
235 size_t alignment_hint = 0);
236 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
237 static void split_reserved_memory(char *base, size_t size,
238 size_t split, bool realloc);
239 static bool commit_memory(char* addr, size_t bytes,
240 bool executable = false);
241 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
242 bool executable = false);
243 static bool uncommit_memory(char* addr, size_t bytes);
244 static bool release_memory(char* addr, size_t bytes);
245
246 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
247 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
248 bool is_committed = true);
249
250 static bool guard_memory(char* addr, size_t bytes);
251 static bool unguard_memory(char* addr, size_t bytes);
252 static bool create_stack_guard_pages(char* addr, size_t bytes);
253 static bool remove_stack_guard_pages(char* addr, size_t bytes);
254
255 static char* map_memory(int fd, const char* file_name, size_t file_offset,
256 char *addr, size_t bytes, bool read_only = false,
257 bool allow_exec = false);
258 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
259 char *addr, size_t bytes, bool read_only,
260 bool allow_exec);
261 static bool unmap_memory(char *addr, size_t bytes);
262 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
263 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
264
265 // NUMA-specific interface
266 static bool numa_has_static_binding();
267 static bool numa_has_group_homing();
268 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
269 static void numa_make_global(char *addr, size_t bytes);
270 static size_t numa_get_groups_num();
271 static size_t numa_get_leaf_groups(int *ids, size_t size);
272 static bool numa_topology_changed();
273 static int numa_get_group_id();
274
275 // Page manipulation
276 struct page_info {
277 size_t size;
278 int lgrp_id;
279 };
280 static bool get_page_info(char *start, page_info* info);
281 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
282
283 static char* non_memory_address_word();
284 // reserve, commit and pin the entire memory region
285 static char* reserve_memory_special(size_t size, char* addr = NULL,
286 bool executable = false);
287 static bool release_memory_special(char* addr, size_t bytes);
288 static void large_page_init();
289 static size_t large_page_size();
290 static bool can_commit_large_page_memory();
291 static bool can_execute_large_page_memory();
292
293 // OS interface to polling page
294 static address get_polling_page() { return _polling_page; }
295 static void set_polling_page(address page) { _polling_page = page; }
296 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
297 static void make_polling_page_unreadable();
298 static void make_polling_page_readable();
299
300 // Routines used to serialize the thread state without using membars
301 static void serialize_thread_states();
302
303 // Since we write to the serialize page from every thread, we
304 // want stores to be on unique cache lines whenever possible
305 // in order to minimize CPU cross talk. We pre-compute the
306 // amount to shift the thread* to make this offset unique to
307 // each thread.
308 static int get_serialize_page_shift_count() {
309 return SerializePageShiftCount;
310 }
311
312 static void set_serialize_page_mask(uintptr_t mask) {
313 _serialize_page_mask = mask;
314 }
315
316 static unsigned int get_serialize_page_mask() {
317 return _serialize_page_mask;
318 }
319
320 static void set_memory_serialize_page(address page);
321
322 static address get_memory_serialize_page() {
323 return (address)_mem_serialize_page;
324 }
325
326 static inline void write_memory_serialize_page(JavaThread *thread) {
327 uintptr_t page_offset = ((uintptr_t)thread >>
328 get_serialize_page_shift_count()) &
329 get_serialize_page_mask();
330 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
331 }
332
333 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
334 if (UseMembar) return false;
335 // Previously this function calculated the exact address of this
336 // thread's serialize page, and checked if the faulting address
337 // was equal. However, some platforms mask off faulting addresses
338 // to the page size, so now we just check that the address is
339 // within the page. This makes the thread argument unnecessary,
340 // but we retain the NULL check to preserve existing behaviour.
341 if (thread == NULL) return false;
342 address page = (address) _mem_serialize_page;
343 return addr >= page && addr < (page + os::vm_page_size());
344 }
345
346 static void block_on_serialize_page_trap();
347
348 // threads
349
350 enum ThreadType {
351 vm_thread,
352 cgc_thread, // Concurrent GC thread
353 pgc_thread, // Parallel GC thread
354 java_thread,
355 compiler_thread,
356 watcher_thread,
357 os_thread
358 };
359
360 static bool create_thread(Thread* thread,
361 ThreadType thr_type,
362 size_t stack_size = 0);
363 static bool create_main_thread(JavaThread* thread);
364 static bool create_attached_thread(JavaThread* thread);
365 static void pd_start_thread(Thread* thread);
366 static void start_thread(Thread* thread);
367
368 static void initialize_thread();
369 static void free_thread(OSThread* osthread);
370
371 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
372 static intx current_thread_id();
373 static int current_process_id();
374 static int sleep(Thread* thread, jlong ms, bool interruptable);
375 static int naked_sleep();
376 static void infinite_sleep(); // never returns, use with CAUTION
377 static void yield(); // Yields to all threads with same priority
378 enum YieldResult {
379 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
380 YIELD_NONEREADY = 0, // No other runnable/ready threads.
381 // platform-specific yield return immediately
382 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
383 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
384 // yield that can be used in lieu of blocking.
385 } ;
386 static YieldResult NakedYield () ;
387 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
388 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
389 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
390 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
391
392 static void interrupt(Thread* thread);
393 static bool is_interrupted(Thread* thread, bool clear_interrupted);
394
395 static int pd_self_suspend_thread(Thread* thread);
396
397 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
398 static frame fetch_frame_from_context(void* ucVoid);
399
400 static ExtendedPC get_thread_pc(Thread *thread);
401 static void breakpoint();
402
403 static address current_stack_pointer();
404 static address current_stack_base();
405 static size_t current_stack_size();
406
407 static int message_box(const char* title, const char* message);
408 static char* do_you_want_to_debug(const char* message);
409
410 // run cmd in a separate process and return its exit code; or -1 on failures
411 static int fork_and_exec(char *cmd);
412
413 // Set file to send error reports.
414 static void set_error_file(const char *logfile);
415
416 // os::exit() is merged with vm_exit()
417 // static void exit(int num);
418
419 // Terminate the VM, but don't exit the process
420 static void shutdown();
421
422 // Terminate with an error. Default is to generate a core file on platforms
423 // that support such things. This calls shutdown() and then aborts.
424 static void abort(bool dump_core = true);
425
426 // Die immediately, no exit hook, no abort hook, no cleanup.
427 static void die();
428
429 // File i/o operations
430 static const int default_file_open_flags();
431 static int open(const char *path, int oflag, int mode);
432 static int close(int fd);
433 static jlong lseek(int fd, jlong offset, int whence);
434 static char* native_path(char *path);
435 static int ftruncate(int fd, jlong length);
436 static int fsync(int fd);
437 static int available(int fd, jlong *bytes);
438
439 //File i/o operations
440
441 static size_t read(int fd, void *buf, unsigned int nBytes);
442 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
443 static size_t write(int fd, const void *buf, unsigned int nBytes);
444
445 // Reading directories.
446 static DIR* opendir(const char* dirname);
447 static int readdir_buf_size(const char *path);
448 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
449 static int closedir(DIR* dirp);
450
451 // Dynamic library extension
452 static const char* dll_file_extension();
453
454 static const char* get_temp_directory();
455 static const char* get_current_directory(char *buf, int buflen);
456
457 // Builds a platform-specific full library path given a ld path and lib name
458 static void dll_build_name(char* buffer, size_t size,
459 const char* pathname, const char* fname);
460
461 // Symbol lookup, find nearest function name; basically it implements
462 // dladdr() for all platforms. Name of the nearest function is copied
463 // to buf. Distance from its base address is returned as offset.
464 // If function name is not found, buf[0] is set to '\0' and offset is
465 // set to -1.
466 static bool dll_address_to_function_name(address addr, char* buf,
467 int buflen, int* offset);
468
469 // Locate DLL/DSO. On success, full path of the library is copied to
470 // buf, and offset is set to be the distance between addr and the
471 // library's base address. On failure, buf[0] is set to '\0' and
472 // offset is set to -1.
473 static bool dll_address_to_library_name(address addr, char* buf,
474 int buflen, int* offset);
475
476 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
477 static bool address_is_in_vm(address addr);
478
479 // Loads .dll/.so and
480 // in case of error it checks if .dll/.so was built for the
481 // same architecture as Hotspot is running on
482 static void* dll_load(const char *name, char *ebuf, int ebuflen);
483
484 // lookup symbol in a shared library
485 static void* dll_lookup(void* handle, const char* name);
486
487 // Unload library
488 static void dll_unload(void *lib);
489
490 // Print out system information; they are called by fatal error handler.
491 // Output format may be different on different platforms.
492 static void print_os_info(outputStream* st);
493 static void print_cpu_info(outputStream* st);
494 static void pd_print_cpu_info(outputStream* st);
495 static void print_memory_info(outputStream* st);
496 static void print_dll_info(outputStream* st);
497 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
498 static void print_context(outputStream* st, void* context);
499 static void print_register_info(outputStream* st, void* context);
500 static void print_siginfo(outputStream* st, void* siginfo);
501 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
502 static void print_date_and_time(outputStream* st);
503
504 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
505 static size_t lasterror(char *buf, size_t len);
506 static int get_last_error();
507
508 // Determines whether the calling process is being debugged by a user-mode debugger.
509 static bool is_debugger_attached();
510
511 // wait for a key press if PauseAtExit is set
512 static void wait_for_keypress_at_exit(void);
513
514 // The following two functions are used by fatal error handler to trace
515 // native (C) frames. They are not part of frame.hpp/frame.cpp because
516 // frame.hpp/cpp assume thread is JavaThread, and also because different
517 // OS/compiler may have different convention or provide different API to
518 // walk C frames.
519 //
520 // We don't attempt to become a debugger, so we only follow frames if that
521 // does not require a lookup in the unwind table, which is part of the binary
522 // file but may be unsafe to read after a fatal error. So on x86, we can
523 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
524 // possible to walk C stack without having the unwind table.
525 static bool is_first_C_frame(frame *fr);
526 static frame get_sender_for_C_frame(frame *fr);
527
528 // return current frame. pc() and sp() are set to NULL on failure.
529 static frame current_frame();
530
531 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
532
533 // returns a string to describe the exception/signal;
534 // returns NULL if exception_code is not an OS exception/signal.
535 static const char* exception_name(int exception_code, char* buf, size_t buflen);
536
537 // Returns native Java library, loads if necessary
538 static void* native_java_library();
539
540 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
541 static void jvm_path(char *buf, jint buflen);
542
543 // Returns true if we are running in a headless jre.
544 static bool is_headless_jre();
545
546 // JNI names
547 static void print_jni_name_prefix_on(outputStream* st, int args_size);
548 static void print_jni_name_suffix_on(outputStream* st, int args_size);
549
550 // File conventions
551 static const char* file_separator();
552 static const char* line_separator();
553 static const char* path_separator();
554
555 // Init os specific system properties values
556 static void init_system_properties_values();
557
558 // IO operations, non-JVM_ version.
559 static int stat(const char* path, struct stat* sbuf);
560 static bool dir_is_empty(const char* path);
561
562 // IO operations on binary files
563 static int create_binary_file(const char* path, bool rewrite_existing);
564 static jlong current_file_offset(int fd);
565 static jlong seek_to_file_offset(int fd, jlong offset);
566
567 // Thread Local Storage
568 static int allocate_thread_local_storage();
569 static void thread_local_storage_at_put(int index, void* value);
570 static void* thread_local_storage_at(int index);
571 static void free_thread_local_storage(int index);
572
573 // General allocation (must be MT-safe)
574 static void* malloc (size_t size);
575 static void* realloc (void *memblock, size_t size);
576 static void free (void *memblock);
577 static bool check_heap(bool force = false); // verify C heap integrity
578 static char* strdup(const char *); // Like strdup
579
580 #ifndef PRODUCT
581 static julong num_mallocs; // # of calls to malloc/realloc
582 static julong alloc_bytes; // # of bytes allocated
583 static julong num_frees; // # of calls to free
584 static julong free_bytes; // # of bytes freed
585 #endif
586
587 // SocketInterface (ex HPI SocketInterface )
588 static int socket(int domain, int type, int protocol);
589 static int socket_close(int fd);
590 static int socket_shutdown(int fd, int howto);
591 static int recv(int fd, char* buf, size_t nBytes, uint flags);
592 static int send(int fd, char* buf, size_t nBytes, uint flags);
593 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
594 static int timeout(int fd, long timeout);
595 static int listen(int fd, int count);
596 static int connect(int fd, struct sockaddr* him, socklen_t len);
597 static int bind(int fd, struct sockaddr* him, socklen_t len);
598 static int accept(int fd, struct sockaddr* him, socklen_t* len);
599 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
600 struct sockaddr* from, socklen_t* fromlen);
601 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
602 static int sendto(int fd, char* buf, size_t len, uint flags,
603 struct sockaddr* to, socklen_t tolen);
604 static int socket_available(int fd, jint* pbytes);
605
606 static int get_sock_opt(int fd, int level, int optname,
607 char* optval, socklen_t* optlen);
608 static int set_sock_opt(int fd, int level, int optname,
609 const char* optval, socklen_t optlen);
610 static int get_host_name(char* name, int namelen);
611
612 static struct hostent* get_host_by_name(char* name);
613
614 // Printing 64 bit integers
615 static const char* jlong_format_specifier();
616 static const char* julong_format_specifier();
617
618 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
619 static void signal_init();
620 static void signal_init_pd();
621 static void signal_notify(int signal_number);
622 static void* signal(int signal_number, void* handler);
623 static void signal_raise(int signal_number);
624 static int signal_wait();
625 static int signal_lookup();
626 static void* user_handler();
627 static void terminate_signal_thread();
628 static int sigexitnum_pd();
629
630 // random number generation
631 static long random(); // return 32bit pseudorandom number
632 static void init_random(long initval); // initialize random sequence
633
634 // Structured OS Exception support
635 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
636
637 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
638 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
639
640 // JVMTI & JVM monitoring and management support
641 // The thread_cpu_time() and current_thread_cpu_time() are only
642 // supported if is_thread_cpu_time_supported() returns true.
643 // They are not supported on Solaris T1.
644
645 // Thread CPU Time - return the fast estimate on a platform
646 // On Solaris - call gethrvtime (fast) - user time only
647 // On Linux - fast clock_gettime where available - user+sys
648 // - otherwise: very slow /proc fs - user+sys
649 // On Windows - GetThreadTimes - user+sys
650 static jlong current_thread_cpu_time();
651 static jlong thread_cpu_time(Thread* t);
652
653 // Thread CPU Time with user_sys_cpu_time parameter.
654 //
655 // If user_sys_cpu_time is true, user+sys time is returned.
656 // Otherwise, only user time is returned
657 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
658 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
659
660 // Return a bunch of info about the timers.
661 // Note that the returned info for these two functions may be different
662 // on some platforms
663 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
664 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
665
666 static bool is_thread_cpu_time_supported();
667
668 // System loadavg support. Returns -1 if load average cannot be obtained.
669 static int loadavg(double loadavg[], int nelem);
670
671 // Hook for os specific jvm options that we don't want to abort on seeing
672 static bool obsolete_option(const JavaVMOption *option);
673
674 // Read file line by line. If line is longer than bsize,
675 // rest of line is skipped. Returns number of bytes read or -1 on EOF
676 static int get_line_chars(int fd, char *buf, const size_t bsize);
677
678 // Extensions
679 #include "runtime/os_ext.hpp"
680
681 public:
682
683 // Platform dependent stuff
684 #ifdef TARGET_OS_FAMILY_linux
685 # include "os_linux.hpp"
686 #endif
687 #ifdef TARGET_OS_FAMILY_solaris
688 # include "os_solaris.hpp"
689 #endif
690 #ifdef TARGET_OS_FAMILY_windows
691 # include "os_windows.hpp"
692 #endif
693 #ifdef TARGET_OS_FAMILY_bsd
694 # include "os_bsd.hpp"
695 #endif
696 #ifdef TARGET_OS_ARCH_linux_x86
697 # include "os_linux_x86.hpp"
698 #endif
699 #ifdef TARGET_OS_ARCH_linux_sparc
700 # include "os_linux_sparc.hpp"
701 #endif
702 #ifdef TARGET_OS_ARCH_linux_zero
703 # include "os_linux_zero.hpp"
704 #endif
705 #ifdef TARGET_OS_ARCH_solaris_x86
706 # include "os_solaris_x86.hpp"
707 #endif
708 #ifdef TARGET_OS_ARCH_solaris_sparc
709 # include "os_solaris_sparc.hpp"
710 #endif
711 #ifdef TARGET_OS_ARCH_windows_x86
712 # include "os_windows_x86.hpp"
713 #endif
714 #ifdef TARGET_OS_ARCH_linux_arm
715 # include "os_linux_arm.hpp"
716 #endif
717 #ifdef TARGET_OS_ARCH_linux_ppc
718 # include "os_linux_ppc.hpp"
719 #endif
720 #ifdef TARGET_OS_ARCH_bsd_x86
721 # include "os_bsd_x86.hpp"
722 #endif
723 #ifdef TARGET_OS_ARCH_bsd_zero
724 # include "os_bsd_zero.hpp"
725 #endif
726
727 public:
728 // debugging support (mostly used by debug.cpp but also fatal error handler)
729 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
730
731 static bool dont_yield(); // when true, JVM_Yield() is nop
732 static void print_statistics();
733
734 // Thread priority helpers (implemented in OS-specific part)
735 static OSReturn set_native_priority(Thread* thread, int native_prio);
736 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
737 static int java_to_os_priority[CriticalPriority + 1];
738 // Hint to the underlying OS that a task switch would not be good.
739 // Void return because it's a hint and can fail.
740 static void hint_no_preempt();
741
742 // Used at creation if requested by the diagnostic flag PauseAtStartup.
743 // Causes the VM to wait until an external stimulus has been applied
744 // (for Unix, that stimulus is a signal, for Windows, an external
745 // ResumeThread call)
746 static void pause();
747
748 protected:
749 static long _rand_seed; // seed for random number generator
750 static int _processor_count; // number of processors
751
752 static char* format_boot_path(const char* format_string,
753 const char* home,
754 int home_len,
755 char fileSep,
756 char pathSep);
757 static bool set_boot_path(char fileSep, char pathSep);
758 static char** split_path(const char* path, int* n);
759 };
760
761 // Note that "PAUSE" is almost always used with synchronization
762 // so arguably we should provide Atomic::SpinPause() instead
763 // of the global SpinPause() with C linkage.
764 // It'd also be eligible for inlining on many platforms.
765
766 extern "C" int SpinPause () ;
767 extern "C" int SafeFetch32 (int * adr, int errValue) ;
768 extern "C" intptr_t SafeFetchN (intptr_t * adr, intptr_t errValue) ;
769
770 #endif // SHARE_VM_RUNTIME_OS_HPP