1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_OS_HPP
26 #define SHARE_VM_RUNTIME_OS_HPP
27
28 #include "jvmtifiles/jvmti.h"
29 #include "runtime/atomic.hpp"
30 #include "runtime/extendedPC.hpp"
31 #include "runtime/handles.hpp"
32 #include "utilities/top.hpp"
33 #ifdef TARGET_OS_FAMILY_linux
34 # include "jvm_linux.h"
35 # include <setjmp.h>
36 #endif
37 #ifdef TARGET_OS_FAMILY_solaris
38 # include "jvm_solaris.h"
39 # include <setjmp.h>
40 #endif
41 #ifdef TARGET_OS_FAMILY_windows
42 # include "jvm_windows.h"
43 #endif
44 #ifdef TARGET_OS_FAMILY_aix
45 # include "jvm_aix.h"
46 # include <setjmp.h>
47 #endif
48 #ifdef TARGET_OS_FAMILY_bsd
49 # include "jvm_bsd.h"
50 # include <setjmp.h>
51 #endif
52
53 class AgentLibrary;
54
55 // os defines the interface to operating system; this includes traditional
56 // OS services (time, I/O) as well as other functionality with system-
57 // dependent code.
58
59 typedef void (*dll_func)(...);
60
61 class Thread;
62 class JavaThread;
63 class Event;
64 class DLL;
65 class FileHandle;
66 template<class E> class GrowableArray;
67
68 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
69
70 // Platform-independent error return values from OS functions
71 enum OSReturn {
72 OS_OK = 0, // Operation was successful
73 OS_ERR = -1, // Operation failed
74 OS_INTRPT = -2, // Operation was interrupted
75 OS_TIMEOUT = -3, // Operation timed out
76 OS_NOMEM = -5, // Operation failed for lack of memory
77 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
78 };
79
80 enum ThreadPriority { // JLS 20.20.1-3
81 NoPriority = -1, // Initial non-priority value
82 MinPriority = 1, // Minimum priority
83 NormPriority = 5, // Normal (non-daemon) priority
84 NearMaxPriority = 9, // High priority, used for VMThread
85 MaxPriority = 10, // Highest priority, used for WatcherThread
86 // ensures that VMThread doesn't starve profiler
87 CriticalPriority = 11 // Critical thread priority
88 };
89
90 // Executable parameter flag for os::commit_memory() and
91 // os::commit_memory_or_exit().
92 const bool ExecMem = true;
93
94 // Typedef for structured exception handling support
95 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
96
97 class os: AllStatic {
98 friend class VMStructs;
99
100 public:
101 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
102
103 private:
104 static OSThread* _starting_thread;
105 static address _polling_page;
106 static volatile int32_t * _mem_serialize_page;
107 static uintptr_t _serialize_page_mask;
108 public:
109 static size_t _page_sizes[page_sizes_max];
110
111 private:
112 static void init_page_sizes(size_t default_page_size) {
113 _page_sizes[0] = default_page_size;
114 _page_sizes[1] = 0; // sentinel
115 }
116
117 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
118 size_t alignment_hint = 0);
119 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
120 static void pd_split_reserved_memory(char *base, size_t size,
121 size_t split, bool realloc);
122 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
123 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
124 bool executable);
125 // Same as pd_commit_memory() that either succeeds or calls
126 // vm_exit_out_of_memory() with the specified mesg.
127 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
128 bool executable, const char* mesg);
129 static void pd_commit_memory_or_exit(char* addr, size_t size,
130 size_t alignment_hint,
131 bool executable, const char* mesg);
132 static bool pd_uncommit_memory(char* addr, size_t bytes);
133 static bool pd_release_memory(char* addr, size_t bytes);
134
135 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
136 char *addr, size_t bytes, bool read_only = false,
137 bool allow_exec = false);
138 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
139 char *addr, size_t bytes, bool read_only,
140 bool allow_exec);
141 static bool pd_unmap_memory(char *addr, size_t bytes);
142 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
143 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
144
145
146 public:
147 static void init(void); // Called before command line parsing
148 static void init_before_ergo(void); // Called after command line parsing
149 // before VM ergonomics processing.
150 static jint init_2(void); // Called after command line parsing
151 // and VM ergonomics processing
152 static void init_globals(void) { // Called from init_globals() in init.cpp
153 init_globals_ext();
154 }
155 static void init_3(void); // Called at the end of vm init
156
157 // File names are case-insensitive on windows only
158 // Override me as needed
159 static int file_name_strcmp(const char* s1, const char* s2);
160
161 static bool getenv(const char* name, char* buffer, int len);
162 static bool have_special_privileges();
163
164 static jlong javaTimeMillis();
165 static jlong javaTimeNanos();
166 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
167 static void run_periodic_checks();
168
169
170 // Returns the elapsed time in seconds since the vm started.
171 static double elapsedTime();
172
173 // Returns real time in seconds since an arbitrary point
174 // in the past.
175 static bool getTimesSecs(double* process_real_time,
176 double* process_user_time,
177 double* process_system_time);
178
179 // Interface to the performance counter
180 static jlong elapsed_counter();
181 static jlong elapsed_frequency();
182
183 // The "virtual time" of a thread is the amount of time a thread has
184 // actually run. The first function indicates whether the OS supports
185 // this functionality for the current thread, and if so:
186 // * the second enables vtime tracking (if that is required).
187 // * the third tells whether vtime is enabled.
188 // * the fourth returns the elapsed virtual time for the current
189 // thread.
190 static bool supports_vtime();
191 static bool enable_vtime();
192 static bool vtime_enabled();
193 static double elapsedVTime();
194
195 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
196 // It is MT safe, but not async-safe, as reading time zone
197 // information may require a lock on some platforms.
198 static char* local_time_string(char *buf, size_t buflen);
199 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
200 // Fill in buffer with current local time as an ISO-8601 string.
201 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
202 // Returns buffer, or NULL if it failed.
203 static char* iso8601_time(char* buffer, size_t buffer_length);
204
205 // Interface for detecting multiprocessor system
206 static inline bool is_MP() {
207 assert(_processor_count > 0, "invalid processor count");
208 return _processor_count > 1 || AssumeMP;
209 }
210 static julong available_memory();
211 static julong physical_memory();
212 static bool has_allocatable_memory_limit(julong* limit);
213 static bool is_server_class_machine();
214
215 // number of CPUs
216 static int processor_count() {
217 return _processor_count;
218 }
219 static void set_processor_count(int count) { _processor_count = count; }
220
221 // Returns the number of CPUs this process is currently allowed to run on.
222 // Note that on some OSes this can change dynamically.
223 static int active_processor_count();
224
225 // Bind processes to processors.
226 // This is a two step procedure:
227 // first you generate a distribution of processes to processors,
228 // then you bind processes according to that distribution.
229 // Compute a distribution for number of processes to processors.
230 // Stores the processor id's into the distribution array argument.
231 // Returns true if it worked, false if it didn't.
232 static bool distribute_processes(uint length, uint* distribution);
233 // Binds the current process to a processor.
234 // Returns true if it worked, false if it didn't.
235 static bool bind_to_processor(uint processor_id);
236
237 // Give a name to the current thread.
238 static void set_native_thread_name(const char *name);
239
240 // Interface for stack banging (predetect possible stack overflow for
241 // exception processing) There are guard pages, and above that shadow
242 // pages for stack overflow checking.
243 static bool uses_stack_guard_pages();
244 static bool allocate_stack_guard_pages();
245 static void bang_stack_shadow_pages();
246 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
247
248 // OS interface to Virtual Memory
249
250 // Return the default page size.
251 static int vm_page_size();
252
253 // Return the page size to use for a region of memory. The min_pages argument
254 // is a hint intended to limit fragmentation; it says the returned page size
255 // should be <= region_max_size / min_pages. Because min_pages is a hint,
256 // this routine may return a size larger than region_max_size / min_pages.
257 //
258 // The current implementation ignores min_pages if a larger page size is an
259 // exact multiple of both region_min_size and region_max_size. This allows
260 // larger pages to be used when doing so would not cause fragmentation; in
261 // particular, a single page can be used when region_min_size ==
262 // region_max_size == a supported page size.
263 static size_t page_size_for_region(size_t region_min_size,
264 size_t region_max_size,
265 uint min_pages);
266 // Return the largest page size that can be used
267 static size_t max_page_size() {
268 // The _page_sizes array is sorted in descending order.
269 return _page_sizes[0];
270 }
271
272 // Methods for tracing page sizes returned by the above method; enabled by
273 // TracePageSizes. The region_{min,max}_size parameters should be the values
274 // passed to page_size_for_region() and page_size should be the result of that
275 // call. The (optional) base and size parameters should come from the
276 // ReservedSpace base() and size() methods.
277 static void trace_page_sizes(const char* str, const size_t* page_sizes,
278 int count) PRODUCT_RETURN;
279 static void trace_page_sizes(const char* str, const size_t region_min_size,
280 const size_t region_max_size,
281 const size_t page_size,
282 const char* base = NULL,
283 const size_t size = 0) PRODUCT_RETURN;
284
285 static int vm_allocation_granularity();
286 static char* reserve_memory(size_t bytes, char* addr = 0,
287 size_t alignment_hint = 0);
288 static char* reserve_memory(size_t bytes, char* addr,
289 size_t alignment_hint, MEMFLAGS flags);
290 static char* reserve_memory_aligned(size_t size, size_t alignment);
291 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
292 static void split_reserved_memory(char *base, size_t size,
293 size_t split, bool realloc);
294 static bool commit_memory(char* addr, size_t bytes, bool executable);
295 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
296 bool executable);
297 // Same as commit_memory() that either succeeds or calls
298 // vm_exit_out_of_memory() with the specified mesg.
299 static void commit_memory_or_exit(char* addr, size_t bytes,
300 bool executable, const char* mesg);
301 static void commit_memory_or_exit(char* addr, size_t size,
302 size_t alignment_hint,
303 bool executable, const char* mesg);
304 static bool uncommit_memory(char* addr, size_t bytes);
305 static bool release_memory(char* addr, size_t bytes);
306
307 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
308 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
309 bool is_committed = true);
310
311 static bool guard_memory(char* addr, size_t bytes);
312 static bool unguard_memory(char* addr, size_t bytes);
313 static bool create_stack_guard_pages(char* addr, size_t bytes);
314 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
315 static bool remove_stack_guard_pages(char* addr, size_t bytes);
316
317 static char* map_memory(int fd, const char* file_name, size_t file_offset,
318 char *addr, size_t bytes, bool read_only = false,
319 bool allow_exec = false);
320 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
321 char *addr, size_t bytes, bool read_only,
322 bool allow_exec);
323 static bool unmap_memory(char *addr, size_t bytes);
324 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
325 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
326
327 // NUMA-specific interface
328 static bool numa_has_static_binding();
329 static bool numa_has_group_homing();
330 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
331 static void numa_make_global(char *addr, size_t bytes);
332 static size_t numa_get_groups_num();
333 static size_t numa_get_leaf_groups(int *ids, size_t size);
334 static bool numa_topology_changed();
335 static int numa_get_group_id();
336
337 // Page manipulation
338 struct page_info {
339 size_t size;
340 int lgrp_id;
341 };
342 static bool get_page_info(char *start, page_info* info);
343 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
344
345 static char* non_memory_address_word();
346 // reserve, commit and pin the entire memory region
347 static char* reserve_memory_special(size_t size, size_t alignment,
348 char* addr, bool executable);
349 static bool release_memory_special(char* addr, size_t bytes);
350 static void large_page_init();
351 static size_t large_page_size();
352 static bool can_commit_large_page_memory();
353 static bool can_execute_large_page_memory();
354
355 // OS interface to polling page
356 static address get_polling_page() { return _polling_page; }
357 static void set_polling_page(address page) { _polling_page = page; }
358 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
359 static void make_polling_page_unreadable();
360 static void make_polling_page_readable();
361
362 // Routines used to serialize the thread state without using membars
363 static void serialize_thread_states();
364
365 // Since we write to the serialize page from every thread, we
366 // want stores to be on unique cache lines whenever possible
367 // in order to minimize CPU cross talk. We pre-compute the
368 // amount to shift the thread* to make this offset unique to
369 // each thread.
370 static int get_serialize_page_shift_count() {
371 return SerializePageShiftCount;
372 }
373
374 static void set_serialize_page_mask(uintptr_t mask) {
375 _serialize_page_mask = mask;
376 }
377
378 static unsigned int get_serialize_page_mask() {
379 return _serialize_page_mask;
380 }
381
382 static void set_memory_serialize_page(address page);
383
384 static address get_memory_serialize_page() {
385 return (address)_mem_serialize_page;
386 }
387
388 static inline void write_memory_serialize_page(JavaThread *thread) {
389 uintptr_t page_offset = ((uintptr_t)thread >>
390 get_serialize_page_shift_count()) &
391 get_serialize_page_mask();
392 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
393 }
394
395 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
396 if (UseMembar) return false;
397 // Previously this function calculated the exact address of this
398 // thread's serialize page, and checked if the faulting address
399 // was equal. However, some platforms mask off faulting addresses
400 // to the page size, so now we just check that the address is
401 // within the page. This makes the thread argument unnecessary,
402 // but we retain the NULL check to preserve existing behaviour.
403 if (thread == NULL) return false;
404 address page = (address) _mem_serialize_page;
405 return addr >= page && addr < (page + os::vm_page_size());
406 }
407
408 static void block_on_serialize_page_trap();
409
410 // threads
411
412 enum ThreadType {
413 vm_thread,
414 cgc_thread, // Concurrent GC thread
415 pgc_thread, // Parallel GC thread
416 java_thread,
417 compiler_thread,
418 watcher_thread,
419 os_thread
420 };
421
422 static bool create_thread(Thread* thread,
423 ThreadType thr_type,
424 size_t stack_size = 0);
425 static bool create_main_thread(JavaThread* thread);
426 static bool create_attached_thread(JavaThread* thread);
427 static void pd_start_thread(Thread* thread);
428 static void start_thread(Thread* thread);
429
430 static void initialize_thread(Thread* thr);
431 static void free_thread(OSThread* osthread);
432
433 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
434 static intx current_thread_id();
435 static int current_process_id();
436 static int sleep(Thread* thread, jlong ms, bool interruptable);
437 // Short standalone OS sleep suitable for slow path spin loop.
438 // Ignores Thread.interrupt() (so keep it short).
439 // ms = 0, will sleep for the least amount of time allowed by the OS.
440 static void naked_short_sleep(jlong ms);
441 static void infinite_sleep(); // never returns, use with CAUTION
442 static void yield(); // Yields to all threads with same priority
443 enum YieldResult {
444 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
445 YIELD_NONEREADY = 0, // No other runnable/ready threads.
446 // platform-specific yield return immediately
447 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
448 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
449 // yield that can be used in lieu of blocking.
450 } ;
451 static YieldResult NakedYield () ;
452 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
453 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
454 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
455 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
456
457 static void interrupt(Thread* thread);
458 static bool is_interrupted(Thread* thread, bool clear_interrupted);
459
460 static int pd_self_suspend_thread(Thread* thread);
461
462 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
463 static frame fetch_frame_from_context(void* ucVoid);
464
465 static ExtendedPC get_thread_pc(Thread *thread);
466 static void breakpoint();
467
468 static address current_stack_pointer();
469 static address current_stack_base();
470 static size_t current_stack_size();
471
472 static void verify_stack_alignment() PRODUCT_RETURN;
473
474 static int message_box(const char* title, const char* message);
475 static char* do_you_want_to_debug(const char* message);
476
477 // run cmd in a separate process and return its exit code; or -1 on failures
478 static int fork_and_exec(char *cmd);
479
480 // Set file to send error reports.
481 static void set_error_file(const char *logfile);
482
483 // os::exit() is merged with vm_exit()
484 // static void exit(int num);
485
486 // Terminate the VM, but don't exit the process
487 static void shutdown();
488
489 // Terminate with an error. Default is to generate a core file on platforms
490 // that support such things. This calls shutdown() and then aborts.
491 static void abort(bool dump_core = true);
492
493 // Die immediately, no exit hook, no abort hook, no cleanup.
494 static void die();
495
496 // File i/o operations
497 static const int default_file_open_flags();
498 static int open(const char *path, int oflag, int mode);
499 static FILE* open(int fd, const char* mode);
500 static int close(int fd);
501 static jlong lseek(int fd, jlong offset, int whence);
502 static char* native_path(char *path);
503 static int ftruncate(int fd, jlong length);
504 static int fsync(int fd);
505 static int available(int fd, jlong *bytes);
506
507 //File i/o operations
508
509 static size_t read(int fd, void *buf, unsigned int nBytes);
510 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
511 static size_t write(int fd, const void *buf, unsigned int nBytes);
512
513 // Reading directories.
514 static DIR* opendir(const char* dirname);
515 static int readdir_buf_size(const char *path);
516 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
517 static int closedir(DIR* dirp);
518
519 // Dynamic library extension
520 static const char* dll_file_extension();
521
522 static const char* get_temp_directory();
523 static const char* get_current_directory(char *buf, size_t buflen);
524
525 // Builds a platform-specific full library path given a ld path and lib name
526 // Returns true if buffer contains full path to existing file, false otherwise
527 static bool dll_build_name(char* buffer, size_t size,
528 const char* pathname, const char* fname);
529
530 // Symbol lookup, find nearest function name; basically it implements
531 // dladdr() for all platforms. Name of the nearest function is copied
532 // to buf. Distance from its base address is optionally returned as offset.
533 // If function name is not found, buf[0] is set to '\0' and offset is
534 // set to -1 (if offset is non-NULL).
535 static bool dll_address_to_function_name(address addr, char* buf,
536 int buflen, int* offset);
537
538 // Locate DLL/DSO. On success, full path of the library is copied to
539 // buf, and offset is optionally set to be the distance between addr
540 // and the library's base address. On failure, buf[0] is set to '\0'
541 // and offset is set to -1 (if offset is non-NULL).
542 static bool dll_address_to_library_name(address addr, char* buf,
543 int buflen, int* offset);
544
545 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
546 static bool address_is_in_vm(address addr);
547
548 // Loads .dll/.so and
549 // in case of error it checks if .dll/.so was built for the
550 // same architecture as Hotspot is running on
551 static void* dll_load(const char *name, char *ebuf, int ebuflen);
552
553 // lookup symbol in a shared library
554 static void* dll_lookup(void* handle, const char* name);
555
556 // Unload library
557 static void dll_unload(void *lib);
558
559 // Return the handle of this process
560 static void* get_default_process_handle();
561
562 // Check for static linked agent library
563 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
564 size_t syms_len);
565
566 // Find agent entry point
567 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
568 const char *syms[], size_t syms_len);
569
570 // Print out system information; they are called by fatal error handler.
571 // Output format may be different on different platforms.
572 static void print_os_info(outputStream* st);
573 static void print_os_info_brief(outputStream* st);
574 static void print_cpu_info(outputStream* st);
575 static void pd_print_cpu_info(outputStream* st);
576 static void print_memory_info(outputStream* st);
577 static void print_dll_info(outputStream* st);
578 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
579 static void print_context(outputStream* st, void* context);
580 static void print_register_info(outputStream* st, void* context);
581 static void print_siginfo(outputStream* st, void* siginfo);
582 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
583 static void print_date_and_time(outputStream* st);
584
585 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
586 static size_t lasterror(char *buf, size_t len);
587 static int get_last_error();
588
589 // Determines whether the calling process is being debugged by a user-mode debugger.
590 static bool is_debugger_attached();
591
592 // wait for a key press if PauseAtExit is set
593 static void wait_for_keypress_at_exit(void);
594
595 // The following two functions are used by fatal error handler to trace
596 // native (C) frames. They are not part of frame.hpp/frame.cpp because
597 // frame.hpp/cpp assume thread is JavaThread, and also because different
598 // OS/compiler may have different convention or provide different API to
599 // walk C frames.
600 //
601 // We don't attempt to become a debugger, so we only follow frames if that
602 // does not require a lookup in the unwind table, which is part of the binary
603 // file but may be unsafe to read after a fatal error. So on x86, we can
604 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
605 // possible to walk C stack without having the unwind table.
606 static bool is_first_C_frame(frame *fr);
607 static frame get_sender_for_C_frame(frame *fr);
608
609 // return current frame. pc() and sp() are set to NULL on failure.
610 static frame current_frame();
611
612 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
613
614 // returns a string to describe the exception/signal;
615 // returns NULL if exception_code is not an OS exception/signal.
616 static const char* exception_name(int exception_code, char* buf, size_t buflen);
617
618 // Returns native Java library, loads if necessary
619 static void* native_java_library();
620
621 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
622 static void jvm_path(char *buf, jint buflen);
623
624 // Returns true if we are running in a headless jre.
625 static bool is_headless_jre();
626
627 // JNI names
628 static void print_jni_name_prefix_on(outputStream* st, int args_size);
629 static void print_jni_name_suffix_on(outputStream* st, int args_size);
630
631 // File conventions
632 static const char* file_separator();
633 static const char* line_separator();
634 static const char* path_separator();
635
636 // Init os specific system properties values
637 static void init_system_properties_values();
638
639 // IO operations, non-JVM_ version.
640 static int stat(const char* path, struct stat* sbuf);
641 static bool dir_is_empty(const char* path);
642
643 // IO operations on binary files
644 static int create_binary_file(const char* path, bool rewrite_existing);
645 static jlong current_file_offset(int fd);
646 static jlong seek_to_file_offset(int fd, jlong offset);
647
648 // Thread Local Storage
649 static int allocate_thread_local_storage();
650 static void thread_local_storage_at_put(int index, void* value);
651 static void* thread_local_storage_at(int index);
652 static void free_thread_local_storage(int index);
653
654 // Stack walk
655 static address get_caller_pc(int n = 0);
656
657 // General allocation (must be MT-safe)
658 static void* malloc (size_t size, MEMFLAGS flags, address caller_pc = 0);
659 static void* realloc (void *memblock, size_t size, MEMFLAGS flags, address caller_pc = 0);
660 static void free (void *memblock, MEMFLAGS flags = mtNone);
661 static bool check_heap(bool force = false); // verify C heap integrity
662 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
663
664 #ifndef PRODUCT
665 static julong num_mallocs; // # of calls to malloc/realloc
666 static julong alloc_bytes; // # of bytes allocated
667 static julong num_frees; // # of calls to free
668 static julong free_bytes; // # of bytes freed
669 #endif
670
671 // SocketInterface (ex HPI SocketInterface )
672 static int socket(int domain, int type, int protocol);
673 static int socket_close(int fd);
674 static int socket_shutdown(int fd, int howto);
675 static int recv(int fd, char* buf, size_t nBytes, uint flags);
676 static int send(int fd, char* buf, size_t nBytes, uint flags);
677 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
678 static int timeout(int fd, long timeout);
679 static int listen(int fd, int count);
680 static int connect(int fd, struct sockaddr* him, socklen_t len);
681 static int bind(int fd, struct sockaddr* him, socklen_t len);
682 static int accept(int fd, struct sockaddr* him, socklen_t* len);
683 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
684 struct sockaddr* from, socklen_t* fromlen);
685 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
686 static int sendto(int fd, char* buf, size_t len, uint flags,
687 struct sockaddr* to, socklen_t tolen);
688 static int socket_available(int fd, jint* pbytes);
689
690 static int get_sock_opt(int fd, int level, int optname,
691 char* optval, socklen_t* optlen);
692 static int set_sock_opt(int fd, int level, int optname,
693 const char* optval, socklen_t optlen);
694 static int get_host_name(char* name, int namelen);
695
696 static struct hostent* get_host_by_name(char* name);
697
698 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
699 static void signal_init();
700 static void signal_init_pd();
701 static void signal_notify(int signal_number);
702 static void* signal(int signal_number, void* handler);
703 static void signal_raise(int signal_number);
704 static int signal_wait();
705 static int signal_lookup();
706 static void* user_handler();
707 static void terminate_signal_thread();
708 static int sigexitnum_pd();
709
710 // random number generation
711 static long random(); // return 32bit pseudorandom number
712 static void init_random(long initval); // initialize random sequence
713
714 // Structured OS Exception support
715 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
716
717 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
718 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
719
720 // Get the default path to the core file
721 // Returns the length of the string
722 static int get_core_path(char* buffer, size_t bufferSize);
723
724 // JVMTI & JVM monitoring and management support
725 // The thread_cpu_time() and current_thread_cpu_time() are only
726 // supported if is_thread_cpu_time_supported() returns true.
727 // They are not supported on Solaris T1.
728
729 // Thread CPU Time - return the fast estimate on a platform
730 // On Solaris - call gethrvtime (fast) - user time only
731 // On Linux - fast clock_gettime where available - user+sys
732 // - otherwise: very slow /proc fs - user+sys
733 // On Windows - GetThreadTimes - user+sys
734 static jlong current_thread_cpu_time();
735 static jlong thread_cpu_time(Thread* t);
736
737 // Thread CPU Time with user_sys_cpu_time parameter.
738 //
739 // If user_sys_cpu_time is true, user+sys time is returned.
740 // Otherwise, only user time is returned
741 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
742 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
743
744 // Return a bunch of info about the timers.
745 // Note that the returned info for these two functions may be different
746 // on some platforms
747 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
748 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
749
750 static bool is_thread_cpu_time_supported();
751
752 // System loadavg support. Returns -1 if load average cannot be obtained.
753 static int loadavg(double loadavg[], int nelem);
754
755 // Hook for os specific jvm options that we don't want to abort on seeing
756 static bool obsolete_option(const JavaVMOption *option);
757
758 // Extensions
759 #include "runtime/os_ext.hpp"
760
761 public:
762 class CrashProtectionCallback : public StackObj {
763 public:
764 virtual void call() = 0;
765 };
766
767 // Platform dependent stuff
768 #ifdef TARGET_OS_FAMILY_linux
769 # include "os_linux.hpp"
770 # include "os_posix.hpp"
771 #endif
772 #ifdef TARGET_OS_FAMILY_solaris
773 # include "os_solaris.hpp"
774 # include "os_posix.hpp"
775 #endif
776 #ifdef TARGET_OS_FAMILY_windows
777 # include "os_windows.hpp"
778 #endif
779 #ifdef TARGET_OS_FAMILY_aix
780 # include "os_aix.hpp"
781 # include "os_posix.hpp"
782 #endif
783 #ifdef TARGET_OS_FAMILY_bsd
784 # include "os_posix.hpp"
785 # include "os_bsd.hpp"
786 #endif
787 #ifdef TARGET_OS_ARCH_linux_x86
788 # include "os_linux_x86.hpp"
789 #endif
790 #ifdef TARGET_OS_ARCH_linux_sparc
791 # include "os_linux_sparc.hpp"
792 #endif
793 #ifdef TARGET_OS_ARCH_linux_zero
794 # include "os_linux_zero.hpp"
795 #endif
796 #ifdef TARGET_OS_ARCH_solaris_x86
797 # include "os_solaris_x86.hpp"
798 #endif
799 #ifdef TARGET_OS_ARCH_solaris_sparc
800 # include "os_solaris_sparc.hpp"
801 #endif
802 #ifdef TARGET_OS_ARCH_windows_x86
803 # include "os_windows_x86.hpp"
804 #endif
805 #ifdef TARGET_OS_ARCH_linux_arm
806 # include "os_linux_arm.hpp"
807 #endif
808 #ifdef TARGET_OS_ARCH_linux_ppc
809 # include "os_linux_ppc.hpp"
810 #endif
811 #ifdef TARGET_OS_ARCH_aix_ppc
812 # include "os_aix_ppc.hpp"
813 #endif
814 #ifdef TARGET_OS_ARCH_bsd_x86
815 # include "os_bsd_x86.hpp"
816 #endif
817 #ifdef TARGET_OS_ARCH_bsd_zero
818 # include "os_bsd_zero.hpp"
819 #endif
820
821 public:
822 #ifndef PLATFORM_PRINT_NATIVE_STACK
823 // No platform-specific code for printing the native stack.
824 static bool platform_print_native_stack(outputStream* st, void* context,
825 char *buf, int buf_size) {
826 return false;
827 }
828 #endif
829
830 // debugging support (mostly used by debug.cpp but also fatal error handler)
831 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
832
833 static bool dont_yield(); // when true, JVM_Yield() is nop
834 static void print_statistics();
835
836 // Thread priority helpers (implemented in OS-specific part)
837 static OSReturn set_native_priority(Thread* thread, int native_prio);
838 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
839 static int java_to_os_priority[CriticalPriority + 1];
840 // Hint to the underlying OS that a task switch would not be good.
841 // Void return because it's a hint and can fail.
842 static void hint_no_preempt();
843
844 // Used at creation if requested by the diagnostic flag PauseAtStartup.
845 // Causes the VM to wait until an external stimulus has been applied
846 // (for Unix, that stimulus is a signal, for Windows, an external
847 // ResumeThread call)
848 static void pause();
849
850 // Builds a platform dependent Agent_OnLoad_<libname> function name
851 // which is used to find statically linked in agents.
852 static char* build_agent_function_name(const char *sym, const char *cname,
853 bool is_absolute_path);
854
855 class SuspendedThreadTaskContext {
856 public:
857 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
858 Thread* thread() const { return _thread; }
859 void* ucontext() const { return _ucontext; }
860 private:
861 Thread* _thread;
862 void* _ucontext;
863 };
864
865 class SuspendedThreadTask {
866 public:
867 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
868 virtual ~SuspendedThreadTask() {}
869 void run();
870 bool is_done() { return _done; }
871 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
872 protected:
873 private:
874 void internal_do_task();
875 Thread* _thread;
876 bool _done;
877 };
878
879 #ifndef TARGET_OS_FAMILY_windows
880 // Suspend/resume support
881 // Protocol:
882 //
883 // a thread starts in SR_RUNNING
884 //
885 // SR_RUNNING can go to
886 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
887 // SR_SUSPEND_REQUEST can go to
888 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
889 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
890 // SR_SUSPENDED can go to
891 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
892 // SR_WAKEUP_REQUEST can go to
893 // * SR_RUNNING when the stopped thread receives the signal
894 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
895 class SuspendResume {
896 public:
897 enum State {
898 SR_RUNNING,
899 SR_SUSPEND_REQUEST,
900 SR_SUSPENDED,
901 SR_WAKEUP_REQUEST
902 };
903
904 private:
905 volatile State _state;
906
907 private:
908 /* try to switch state from state "from" to state "to"
909 * returns the state set after the method is complete
910 */
911 State switch_state(State from, State to);
912
913 public:
914 SuspendResume() : _state(SR_RUNNING) { }
915
916 State state() const { return _state; }
917
918 State request_suspend() {
919 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
920 }
921
922 State cancel_suspend() {
923 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
924 }
925
926 State suspended() {
927 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
928 }
929
930 State request_wakeup() {
931 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
932 }
933
934 State running() {
935 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
936 }
937
938 bool is_running() const {
939 return _state == SR_RUNNING;
940 }
941
942 bool is_suspend_request() const {
943 return _state == SR_SUSPEND_REQUEST;
944 }
945
946 bool is_suspended() const {
947 return _state == SR_SUSPENDED;
948 }
949 };
950 #endif
951
952
953 protected:
954 static long _rand_seed; // seed for random number generator
955 static int _processor_count; // number of processors
956
957 static char* format_boot_path(const char* format_string,
958 const char* home,
959 int home_len,
960 char fileSep,
961 char pathSep);
962 static bool set_boot_path(char fileSep, char pathSep);
963 static char** split_path(const char* path, int* n);
964
965 };
966
967 // Note that "PAUSE" is almost always used with synchronization
968 // so arguably we should provide Atomic::SpinPause() instead
969 // of the global SpinPause() with C linkage.
970 // It'd also be eligible for inlining on many platforms.
971
972 extern "C" int SpinPause();
973
974 #endif // SHARE_VM_RUNTIME_OS_HPP