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 };
79
80 // Typedef for structured exception handling support
81 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
82
83 class os: AllStatic {
84 public:
85 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
86
87 private:
88 static OSThread* _starting_thread;
89 static address _polling_page;
90 static volatile int32_t * _mem_serialize_page;
91 static uintptr_t _serialize_page_mask;
92 public:
93 static size_t _page_sizes[page_sizes_max];
94
95 private:
96 static void init_page_sizes(size_t default_page_size) {
97 _page_sizes[0] = default_page_size;
98 _page_sizes[1] = 0; // sentinel
99 }
100
101 public:
102
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_3(void); // Called at the end of vm init
106
107 // File names are case-insensitive on windows only
108 // Override me as needed
109 static int file_name_strcmp(const char* s1, const char* s2);
110
111 static bool getenv(const char* name, char* buffer, int len);
112 static bool have_special_privileges();
113
114 static jlong javaTimeMillis();
115 static jlong javaTimeNanos();
116 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
117 static void run_periodic_checks();
118
119
120 // Returns the elapsed time in seconds since the vm started.
121 static double elapsedTime();
122
123 // Returns real time in seconds since an arbitrary point
124 // in the past.
125 static bool getTimesSecs(double* process_real_time,
126 double* process_user_time,
127 double* process_system_time);
128
129 // Interface to the performance counter
130 static jlong elapsed_counter();
131 static jlong elapsed_frequency();
132
133 // The "virtual time" of a thread is the amount of time a thread has
134 // actually run. The first function indicates whether the OS supports
135 // this functionality for the current thread, and if so:
136 // * the second enables vtime tracking (if that is required).
137 // * the third tells whether vtime is enabled.
138 // * the fourth returns the elapsed virtual time for the current
139 // thread.
140 static bool supports_vtime();
141 static bool enable_vtime();
142 static bool vtime_enabled();
143 static double elapsedVTime();
144
145 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
146 // It is MT safe, but not async-safe, as reading time zone
147 // information may require a lock on some platforms.
148 static char* local_time_string(char *buf, size_t buflen);
149 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
150 // Fill in buffer with current local time as an ISO-8601 string.
151 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
152 // Returns buffer, or NULL if it failed.
153 static char* iso8601_time(char* buffer, size_t buffer_length);
154
155 // Interface for detecting multiprocessor system
156 static inline bool is_MP() {
157 assert(_processor_count > 0, "invalid processor count");
158 return _processor_count > 1;
159 }
160 static julong available_memory();
161 static julong physical_memory();
162 static julong allocatable_physical_memory(julong size);
163 static bool is_server_class_machine();
164
165 // number of CPUs
166 static int processor_count() {
167 return _processor_count;
168 }
169 static void set_processor_count(int count) { _processor_count = count; }
170
171 // Returns the number of CPUs this process is currently allowed to run on.
172 // Note that on some OSes this can change dynamically.
173 static int active_processor_count();
174
175 // Bind processes to processors.
176 // This is a two step procedure:
177 // first you generate a distribution of processes to processors,
178 // then you bind processes according to that distribution.
179 // Compute a distribution for number of processes to processors.
180 // Stores the processor id's into the distribution array argument.
181 // Returns true if it worked, false if it didn't.
182 static bool distribute_processes(uint length, uint* distribution);
183 // Binds the current process to a processor.
184 // Returns true if it worked, false if it didn't.
185 static bool bind_to_processor(uint processor_id);
186
187 // Give a name to the current thread.
188 static void set_native_thread_name(const char *name);
189
190 // Interface for stack banging (predetect possible stack overflow for
191 // exception processing) There are guard pages, and above that shadow
192 // pages for stack overflow checking.
193 static bool uses_stack_guard_pages();
194 static bool allocate_stack_guard_pages();
195 static void bang_stack_shadow_pages();
196 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
197
198 // OS interface to Virtual Memory
199
200 // Return the default page size.
201 static int vm_page_size();
202
203 // Return the page size to use for a region of memory. The min_pages argument
204 // is a hint intended to limit fragmentation; it says the returned page size
205 // should be <= region_max_size / min_pages. Because min_pages is a hint,
206 // this routine may return a size larger than region_max_size / min_pages.
207 //
208 // The current implementation ignores min_pages if a larger page size is an
209 // exact multiple of both region_min_size and region_max_size. This allows
210 // larger pages to be used when doing so would not cause fragmentation; in
211 // particular, a single page can be used when region_min_size ==
212 // region_max_size == a supported page size.
213 static size_t page_size_for_region(size_t region_min_size,
214 size_t region_max_size,
215 uint min_pages);
216
217 // Methods for tracing page sizes returned by the above method; enabled by
218 // TracePageSizes. The region_{min,max}_size parameters should be the values
219 // passed to page_size_for_region() and page_size should be the result of that
220 // call. The (optional) base and size parameters should come from the
221 // ReservedSpace base() and size() methods.
222 static void trace_page_sizes(const char* str, const size_t* page_sizes,
223 int count) PRODUCT_RETURN;
224 static void trace_page_sizes(const char* str, const size_t region_min_size,
225 const size_t region_max_size,
226 const size_t page_size,
227 const char* base = NULL,
228 const size_t size = 0) PRODUCT_RETURN;
229
230 static int vm_allocation_granularity();
231 static char* reserve_memory(size_t bytes, char* addr = 0,
232 size_t alignment_hint = 0);
233 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
234 static void split_reserved_memory(char *base, size_t size,
235 size_t split, bool realloc);
236 static bool commit_memory(char* addr, size_t bytes,
237 bool executable = false);
238 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
239 bool executable = false);
240 static bool uncommit_memory(char* addr, size_t bytes);
241 static bool release_memory(char* addr, size_t bytes);
242
243 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
244 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
245 bool is_committed = true);
246
247 static bool guard_memory(char* addr, size_t bytes);
248 static bool unguard_memory(char* addr, size_t bytes);
249 static bool create_stack_guard_pages(char* addr, size_t bytes);
250 static bool remove_stack_guard_pages(char* addr, size_t bytes);
251
252 static char* map_memory(int fd, const char* file_name, size_t file_offset,
253 char *addr, size_t bytes, bool read_only = false,
254 bool allow_exec = false);
255 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
256 char *addr, size_t bytes, bool read_only,
257 bool allow_exec);
258 static bool unmap_memory(char *addr, size_t bytes);
259 static void free_memory(char *addr, size_t bytes);
260 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
261
262 // NUMA-specific interface
263 static bool numa_has_static_binding();
264 static bool numa_has_group_homing();
265 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
266 static void numa_make_global(char *addr, size_t bytes);
267 static size_t numa_get_groups_num();
268 static size_t numa_get_leaf_groups(int *ids, size_t size);
269 static bool numa_topology_changed();
270 static int numa_get_group_id();
271
272 // Page manipulation
273 struct page_info {
274 size_t size;
275 int lgrp_id;
276 };
277 static bool get_page_info(char *start, page_info* info);
278 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
279
280 static char* non_memory_address_word();
281 // reserve, commit and pin the entire memory region
282 static char* reserve_memory_special(size_t size, char* addr = NULL,
283 bool executable = false);
284 static bool release_memory_special(char* addr, size_t bytes);
285 static void large_page_init();
286 static size_t large_page_size();
287 static bool can_commit_large_page_memory();
288 static bool can_execute_large_page_memory();
289
290 // OS interface to polling page
291 static address get_polling_page() { return _polling_page; }
292 static void set_polling_page(address page) { _polling_page = page; }
293 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
294 static void make_polling_page_unreadable();
295 static void make_polling_page_readable();
296
297 // Routines used to serialize the thread state without using membars
298 static void serialize_thread_states();
299
300 // Since we write to the serialize page from every thread, we
301 // want stores to be on unique cache lines whenever possible
302 // in order to minimize CPU cross talk. We pre-compute the
303 // amount to shift the thread* to make this offset unique to
304 // each thread.
305 static int get_serialize_page_shift_count() {
306 return SerializePageShiftCount;
307 }
308
309 static void set_serialize_page_mask(uintptr_t mask) {
310 _serialize_page_mask = mask;
311 }
312
313 static unsigned int get_serialize_page_mask() {
314 return _serialize_page_mask;
315 }
316
317 static void set_memory_serialize_page(address page);
318
319 static address get_memory_serialize_page() {
320 return (address)_mem_serialize_page;
321 }
322
323 static inline void write_memory_serialize_page(JavaThread *thread) {
324 uintptr_t page_offset = ((uintptr_t)thread >>
325 get_serialize_page_shift_count()) &
326 get_serialize_page_mask();
327 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
328 }
329
330 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
331 if (UseMembar) return false;
332 // Previously this function calculated the exact address of this
333 // thread's serialize page, and checked if the faulting address
334 // was equal. However, some platforms mask off faulting addresses
335 // to the page size, so now we just check that the address is
336 // within the page. This makes the thread argument unnecessary,
337 // but we retain the NULL check to preserve existing behaviour.
338 if (thread == NULL) return false;
339 address page = (address) _mem_serialize_page;
340 return addr >= page && addr < (page + os::vm_page_size());
341 }
342
343 static void block_on_serialize_page_trap();
344
345 // threads
346
347 enum ThreadType {
348 vm_thread,
349 cgc_thread, // Concurrent GC thread
350 pgc_thread, // Parallel GC thread
351 java_thread,
352 compiler_thread,
353 watcher_thread,
354 os_thread
355 };
356
357 static bool create_thread(Thread* thread,
358 ThreadType thr_type,
359 size_t stack_size = 0);
360 static bool create_main_thread(JavaThread* thread);
361 static bool create_attached_thread(JavaThread* thread);
362 static void pd_start_thread(Thread* thread);
363 static void start_thread(Thread* thread);
364
365 static void initialize_thread();
366 static void free_thread(OSThread* osthread);
367
368 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
369 static intx current_thread_id();
370 static int current_process_id();
371 static int sleep(Thread* thread, jlong ms, bool interruptable);
372 static int naked_sleep();
373 static void infinite_sleep(); // never returns, use with CAUTION
374 static void yield(); // Yields to all threads with same priority
375 enum YieldResult {
376 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
377 YIELD_NONEREADY = 0, // No other runnable/ready threads.
378 // platform-specific yield return immediately
379 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
380 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
381 // yield that can be used in lieu of blocking.
382 } ;
383 static YieldResult NakedYield () ;
384 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
385 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
386 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
387 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
388
389 static void interrupt(Thread* thread);
390 static bool is_interrupted(Thread* thread, bool clear_interrupted);
391
392 static int pd_self_suspend_thread(Thread* thread);
393
394 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
395 static frame fetch_frame_from_context(void* ucVoid);
396
397 static ExtendedPC get_thread_pc(Thread *thread);
398 static void breakpoint();
399
400 static address current_stack_pointer();
401 static address current_stack_base();
402 static size_t current_stack_size();
403
404 static int message_box(const char* title, const char* message);
405 static char* do_you_want_to_debug(const char* message);
406
407 // run cmd in a separate process and return its exit code; or -1 on failures
408 static int fork_and_exec(char *cmd);
409
410 // Set file to send error reports.
411 static void set_error_file(const char *logfile);
412
413 // os::exit() is merged with vm_exit()
414 // static void exit(int num);
415
416 // Terminate the VM, but don't exit the process
417 static void shutdown();
418
419 // Terminate with an error. Default is to generate a core file on platforms
420 // that support such things. This calls shutdown() and then aborts.
421 static void abort(bool dump_core = true);
422
423 // Die immediately, no exit hook, no abort hook, no cleanup.
424 static void die();
425
426 // File i/o operations
427 static const int default_file_open_flags();
428 static int open(const char *path, int oflag, int mode);
429 static int close(int fd);
430 static jlong lseek(int fd, jlong offset, int whence);
431 static char* native_path(char *path);
432 static int ftruncate(int fd, jlong length);
433 static int fsync(int fd);
434 static int available(int fd, jlong *bytes);
435
436 //File i/o operations
437
438 static size_t read(int fd, void *buf, unsigned int nBytes);
439 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
440 static size_t write(int fd, const void *buf, unsigned int nBytes);
441
442 // Reading directories.
443 static DIR* opendir(const char* dirname);
444 static int readdir_buf_size(const char *path);
445 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
446 static int closedir(DIR* dirp);
447
448 // Dynamic library extension
449 static const char* dll_file_extension();
450
451 static const char* get_temp_directory();
452 static const char* get_current_directory(char *buf, int buflen);
453
454 // Builds a platform-specific full library path given a ld path and lib name
455 static void dll_build_name(char* buffer, size_t size,
456 const char* pathname, const char* fname);
457
458 // Symbol lookup, find nearest function name; basically it implements
459 // dladdr() for all platforms. Name of the nearest function is copied
460 // to buf. Distance from its base address is returned as offset.
461 // If function name is not found, buf[0] is set to '\0' and offset is
462 // set to -1.
463 static bool dll_address_to_function_name(address addr, char* buf,
464 int buflen, int* offset);
465
466 // Locate DLL/DSO. On success, full path of the library is copied to
467 // buf, and offset is set to be the distance between addr and the
468 // library's base address. On failure, buf[0] is set to '\0' and
469 // offset is set to -1.
470 static bool dll_address_to_library_name(address addr, char* buf,
471 int buflen, int* offset);
472
473 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
474 static bool address_is_in_vm(address addr);
475
476 // Loads .dll/.so and
477 // in case of error it checks if .dll/.so was built for the
478 // same architecture as Hotspot is running on
479 static void* dll_load(const char *name, char *ebuf, int ebuflen);
480
481 // lookup symbol in a shared library
482 static void* dll_lookup(void* handle, const char* name);
483
484 // Unload library
485 static void dll_unload(void *lib);
486
487 // Print out system information; they are called by fatal error handler.
488 // Output format may be different on different platforms.
489 static void print_os_info(outputStream* st);
490 static void print_cpu_info(outputStream* st);
491 static void pd_print_cpu_info(outputStream* st);
492 static void print_memory_info(outputStream* st);
493 static void print_dll_info(outputStream* st);
494 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
495 static void print_context(outputStream* st, void* context);
496 static void print_register_info(outputStream* st, void* context);
497 static void print_siginfo(outputStream* st, void* siginfo);
498 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
499 static void print_date_and_time(outputStream* st);
500
501 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
502 static size_t lasterror(char *buf, size_t len);
503
504 // Determines whether the calling process is being debugged by a user-mode debugger.
505 static bool is_debugger_attached();
506
507 // wait for a key press if PauseAtExit is set
508 static void wait_for_keypress_at_exit(void);
509
510 // The following two functions are used by fatal error handler to trace
511 // native (C) frames. They are not part of frame.hpp/frame.cpp because
512 // frame.hpp/cpp assume thread is JavaThread, and also because different
513 // OS/compiler may have different convention or provide different API to
514 // walk C frames.
515 //
516 // We don't attempt to become a debugger, so we only follow frames if that
517 // does not require a lookup in the unwind table, which is part of the binary
518 // file but may be unsafe to read after a fatal error. So on x86, we can
519 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
520 // possible to walk C stack without having the unwind table.
521 static bool is_first_C_frame(frame *fr);
522 static frame get_sender_for_C_frame(frame *fr);
523
524 // return current frame. pc() and sp() are set to NULL on failure.
525 static frame current_frame();
526
527 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
528
529 // returns a string to describe the exception/signal;
530 // returns NULL if exception_code is not an OS exception/signal.
531 static const char* exception_name(int exception_code, char* buf, size_t buflen);
532
533 // Returns native Java library, loads if necessary
534 static void* native_java_library();
535
536 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
537 static void jvm_path(char *buf, jint buflen);
538
539 // Returns true if we are running in a headless jre.
540 static bool is_headless_jre();
541
542 // JNI names
543 static void print_jni_name_prefix_on(outputStream* st, int args_size);
544 static void print_jni_name_suffix_on(outputStream* st, int args_size);
545
546 // File conventions
547 static const char* file_separator();
548 static const char* line_separator();
549 static const char* path_separator();
550
551 // Init os specific system properties values
552 static void init_system_properties_values();
553
554 // IO operations, non-JVM_ version.
555 static int stat(const char* path, struct stat* sbuf);
556 static bool dir_is_empty(const char* path);
557
558 // IO operations on binary files
559 static int create_binary_file(const char* path, bool rewrite_existing);
560 static jlong current_file_offset(int fd);
561 static jlong seek_to_file_offset(int fd, jlong offset);
562
563 // Thread Local Storage
564 static int allocate_thread_local_storage();
565 static void thread_local_storage_at_put(int index, void* value);
566 static void* thread_local_storage_at(int index);
567 static void free_thread_local_storage(int index);
568
569 // General allocation (must be MT-safe)
570 static void* malloc (size_t size);
571 static void* realloc (void *memblock, size_t size);
572 static void free (void *memblock);
573 static bool check_heap(bool force = false); // verify C heap integrity
574 static char* strdup(const char *); // Like strdup
575
576 #ifndef PRODUCT
577 static julong num_mallocs; // # of calls to malloc/realloc
578 static julong alloc_bytes; // # of bytes allocated
579 static julong num_frees; // # of calls to free
580 static julong free_bytes; // # of bytes freed
581 #endif
582
583 // SocketInterface (ex HPI SocketInterface )
584 static int socket(int domain, int type, int protocol);
585 static int socket_close(int fd);
586 static int socket_shutdown(int fd, int howto);
587 static int recv(int fd, char *buf, int nBytes, int flags);
588 static int send(int fd, char *buf, int nBytes, int flags);
589 static int raw_send(int fd, char *buf, int nBytes, int flags);
590 static int timeout(int fd, long timeout);
591 static int listen(int fd, int count);
592 static int connect(int fd, struct sockaddr *him, int len);
593 static int bind(int fd, struct sockaddr *him, int len);
594 static int accept(int fd, struct sockaddr *him, int *len);
595 static int recvfrom(int fd, char *buf, int nbytes, int flags,
596 struct sockaddr *from, int *fromlen);
597 static int get_sock_name(int fd, struct sockaddr *him, int *len);
598 static int sendto(int fd, char *buf, int len, int flags,
599 struct sockaddr *to, int tolen);
600 static int socket_available(int fd, jint *pbytes);
601
602 static int get_sock_opt(int fd, int level, int optname,
603 char *optval, int* optlen);
604 static int set_sock_opt(int fd, int level, int optname,
605 const char *optval, int optlen);
606 static int get_host_name(char* name, int namelen);
607
608 static struct hostent* get_host_by_name(char* name);
609
610 // Printing 64 bit integers
611 static const char* jlong_format_specifier();
612 static const char* julong_format_specifier();
613
614 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
615 static void signal_init();
616 static void signal_init_pd();
617 static void signal_notify(int signal_number);
618 static void* signal(int signal_number, void* handler);
619 static void signal_raise(int signal_number);
620 static int signal_wait();
621 static int signal_lookup();
622 static void* user_handler();
623 static void terminate_signal_thread();
624 static int sigexitnum_pd();
625
626 // random number generation
627 static long random(); // return 32bit pseudorandom number
628 static void init_random(long initval); // initialize random sequence
629
630 // Structured OS Exception support
631 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
632
633 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
634 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
635
636 // JVMTI & JVM monitoring and management support
637 // The thread_cpu_time() and current_thread_cpu_time() are only
638 // supported if is_thread_cpu_time_supported() returns true.
639 // They are not supported on Solaris T1.
640
641 // Thread CPU Time - return the fast estimate on a platform
642 // On Solaris - call gethrvtime (fast) - user time only
643 // On Linux - fast clock_gettime where available - user+sys
644 // - otherwise: very slow /proc fs - user+sys
645 // On Windows - GetThreadTimes - user+sys
646 static jlong current_thread_cpu_time();
647 static jlong thread_cpu_time(Thread* t);
648
649 // Thread CPU Time with user_sys_cpu_time parameter.
650 //
651 // If user_sys_cpu_time is true, user+sys time is returned.
652 // Otherwise, only user time is returned
653 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
654 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
655
656 // Return a bunch of info about the timers.
657 // Note that the returned info for these two functions may be different
658 // on some platforms
659 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
660 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
661
662 static bool is_thread_cpu_time_supported();
663
664 // System loadavg support. Returns -1 if load average cannot be obtained.
665 static int loadavg(double loadavg[], int nelem);
666
667 // Hook for os specific jvm options that we don't want to abort on seeing
668 static bool obsolete_option(const JavaVMOption *option);
669
670 // Read file line by line. If line is longer than bsize,
671 // rest of line is skipped. Returns number of bytes read or -1 on EOF
672 static int get_line_chars(int fd, char *buf, const size_t bsize);
673
674 // Platform dependent stuff
675 #ifdef TARGET_OS_FAMILY_linux
676 # include "os_linux.hpp"
677 #endif
678 #ifdef TARGET_OS_FAMILY_solaris
679 # include "os_solaris.hpp"
680 #endif
681 #ifdef TARGET_OS_FAMILY_windows
682 # include "os_windows.hpp"
683 #endif
684 #ifdef TARGET_OS_FAMILY_bsd
685 # include "os_bsd.hpp"
686 #endif
687 #ifdef TARGET_OS_ARCH_linux_x86
688 # include "os_linux_x86.hpp"
689 #endif
690 #ifdef TARGET_OS_ARCH_linux_sparc
691 # include "os_linux_sparc.hpp"
692 #endif
693 #ifdef TARGET_OS_ARCH_linux_zero
694 # include "os_linux_zero.hpp"
695 #endif
696 #ifdef TARGET_OS_ARCH_solaris_x86
697 # include "os_solaris_x86.hpp"
698 #endif
699 #ifdef TARGET_OS_ARCH_solaris_sparc
700 # include "os_solaris_sparc.hpp"
701 #endif
702 #ifdef TARGET_OS_ARCH_windows_x86
703 # include "os_windows_x86.hpp"
704 #endif
705 #ifdef TARGET_OS_ARCH_linux_arm
706 # include "os_linux_arm.hpp"
707 #endif
708 #ifdef TARGET_OS_ARCH_linux_ppc
709 # include "os_linux_ppc.hpp"
710 #endif
711 #ifdef TARGET_OS_ARCH_bsd_x86
712 # include "os_bsd_x86.hpp"
713 #endif
714 #ifdef TARGET_OS_ARCH_bsd_zero
715 # include "os_bsd_zero.hpp"
716 #endif
717
718
719 // debugging support (mostly used by debug.cpp but also fatal error handler)
720 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
721
722 static bool dont_yield(); // when true, JVM_Yield() is nop
723 static void print_statistics();
724
725 // Thread priority helpers (implemented in OS-specific part)
726 static OSReturn set_native_priority(Thread* thread, int native_prio);
727 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
728 static int java_to_os_priority[MaxPriority + 1];
729 // Hint to the underlying OS that a task switch would not be good.
730 // Void return because it's a hint and can fail.
731 static void hint_no_preempt();
732
733 // Used at creation if requested by the diagnostic flag PauseAtStartup.
734 // Causes the VM to wait until an external stimulus has been applied
735 // (for Unix, that stimulus is a signal, for Windows, an external
736 // ResumeThread call)
737 static void pause();
738
739 protected:
740 static long _rand_seed; // seed for random number generator
741 static int _processor_count; // number of processors
742
743 static char* format_boot_path(const char* format_string,
744 const char* home,
745 int home_len,
746 char fileSep,
747 char pathSep);
748 static bool set_boot_path(char fileSep, char pathSep);
749 static char** split_path(const char* path, int* n);
750 };
751
752 // Note that "PAUSE" is almost always used with synchronization
753 // so arguably we should provide Atomic::SpinPause() instead
754 // of the global SpinPause() with C linkage.
755 // It'd also be eligible for inlining on many platforms.
756
757 extern "C" int SpinPause () ;
758 extern "C" int SafeFetch32 (int * adr, int errValue) ;
759 extern "C" intptr_t SafeFetchN (intptr_t * adr, intptr_t errValue) ;
760
761 #endif // SHARE_VM_RUNTIME_OS_HPP