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