1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_OS_HPP
26 #define SHARE_VM_RUNTIME_OS_HPP
27
28 #include "jvmtifiles/jvmti.h"
29 #include "runtime/extendedPC.hpp"
30 #include "runtime/handles.hpp"
31 #include "utilities/top.hpp"
32 #ifdef TARGET_OS_FAMILY_linux
33 # include "jvm_linux.h"
34 # include <setjmp.h>
35 #endif
36 #ifdef TARGET_OS_FAMILY_solaris
37 # include "jvm_solaris.h"
38 # include <setjmp.h>
39 #endif
40 #ifdef TARGET_OS_FAMILY_windows
41 # include "jvm_windows.h"
42 #endif
43 #ifdef TARGET_OS_FAMILY_aix
44 # include "jvm_aix.h"
45 # include <setjmp.h>
46 #endif
47 #ifdef TARGET_OS_FAMILY_bsd
48 # include "jvm_bsd.h"
49 # include <setjmp.h>
50 # ifdef __APPLE__
51 # include <mach/mach_time.h>
52 # endif
53 #endif
54
55 class AgentLibrary;
56
57 // os defines the interface to operating system; this includes traditional
58 // OS services (time, I/O) as well as other functionality with system-
59 // dependent code.
60
61 typedef void (*dll_func)(...);
62
63 class Thread;
64 class JavaThread;
65 class Event;
66 class DLL;
67 class FileHandle;
68 class NativeCallStack;
69
70 template<class E> class GrowableArray;
71
72 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
73
74 // Platform-independent error return values from OS functions
75 enum OSReturn {
76 OS_OK = 0, // Operation was successful
77 OS_ERR = -1, // Operation failed
78 OS_INTRPT = -2, // Operation was interrupted
79 OS_TIMEOUT = -3, // Operation timed out
80 OS_NOMEM = -5, // Operation failed for lack of memory
81 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
82 };
83
84 enum ThreadPriority { // JLS 20.20.1-3
85 NoPriority = -1, // Initial non-priority value
86 MinPriority = 1, // Minimum priority
87 NormPriority = 5, // Normal (non-daemon) priority
88 NearMaxPriority = 9, // High priority, used for VMThread
89 MaxPriority = 10, // Highest priority, used for WatcherThread
90 // ensures that VMThread doesn't starve profiler
91 CriticalPriority = 11 // Critical thread priority
92 };
93
94 // Executable parameter flag for os::commit_memory() and
95 // os::commit_memory_or_exit().
96 const bool ExecMem = true;
97
98 // Typedef for structured exception handling support
99 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
100
101 class MallocTracker;
102
103 class os: AllStatic {
104 friend class VMStructs;
105 friend class MallocTracker;
106 public:
107 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
108
109 private:
110 static OSThread* _starting_thread;
111 static address _polling_page;
112 static volatile int32_t * _mem_serialize_page;
113 static uintptr_t _serialize_page_mask;
114 public:
115 static size_t _page_sizes[page_sizes_max];
116
117 private:
118 static void init_page_sizes(size_t default_page_size) {
119 _page_sizes[0] = default_page_size;
120 _page_sizes[1] = 0; // sentinel
121 }
122
123 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
124 size_t alignment_hint = 0);
125 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
126 static void pd_split_reserved_memory(char *base, size_t size,
127 size_t split, bool realloc);
128 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
129 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
130 bool executable);
131 // Same as pd_commit_memory() that either succeeds or calls
132 // vm_exit_out_of_memory() with the specified mesg.
133 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
134 bool executable, const char* mesg);
135 static void pd_commit_memory_or_exit(char* addr, size_t size,
136 size_t alignment_hint,
137 bool executable, const char* mesg);
138 static bool pd_uncommit_memory(char* addr, size_t bytes);
139 static bool pd_release_memory(char* addr, size_t bytes);
140
141 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
142 char *addr, size_t bytes, bool read_only = false,
143 bool allow_exec = false);
144 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
145 char *addr, size_t bytes, bool read_only,
146 bool allow_exec);
147 static bool pd_unmap_memory(char *addr, size_t bytes);
148 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
149 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
150
151
152 public:
153 static void init(void); // Called before command line parsing
154 static void init_before_ergo(void); // Called after command line parsing
155 // before VM ergonomics processing.
156 static jint init_2(void); // Called after command line parsing
157 // and VM ergonomics processing
158 static void init_globals(void) { // Called from init_globals() in init.cpp
159 init_globals_ext();
160 }
161 static void init_3(void); // Called at the end of vm init
162
163 // File names are case-insensitive on windows only
164 // Override me as needed
165 static int file_name_strcmp(const char* s1, const char* s2);
166
167 // get/unset environment variable
168 static bool getenv(const char* name, char* buffer, int len);
169 static bool unsetenv(const char* name);
170
171 static bool have_special_privileges();
172
173 static jlong javaTimeMillis();
174 static jlong javaTimeNanos();
175 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
176 static void run_periodic_checks();
177
178
179 // Returns the elapsed time in seconds since the vm started.
180 static double elapsedTime();
181
182 // Returns real time in seconds since an arbitrary point
183 // in the past.
184 static bool getTimesSecs(double* process_real_time,
185 double* process_user_time,
186 double* process_system_time);
187
188 // Interface to the performance counter
189 static jlong elapsed_counter();
190 static jlong elapsed_frequency();
191
192 // The "virtual time" of a thread is the amount of time a thread has
193 // actually run. The first function indicates whether the OS supports
194 // this functionality for the current thread, and if so:
195 // * the second enables vtime tracking (if that is required).
196 // * the third tells whether vtime is enabled.
197 // * the fourth returns the elapsed virtual time for the current
198 // thread.
199 static bool supports_vtime();
200 static bool enable_vtime();
201 static bool vtime_enabled();
202 static double elapsedVTime();
203
204 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
205 // It is MT safe, but not async-safe, as reading time zone
206 // information may require a lock on some platforms.
207 static char* local_time_string(char *buf, size_t buflen);
208 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
209 // Fill in buffer with current local time as an ISO-8601 string.
210 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
211 // Returns buffer, or NULL if it failed.
212 static char* iso8601_time(char* buffer, size_t buffer_length);
213
214 // Interface for detecting multiprocessor system
215 static inline bool is_MP() {
216 #if !INCLUDE_NMT
217 assert(_processor_count > 0, "invalid processor count");
218 return _processor_count > 1 || AssumeMP;
219 #else
220 // NMT needs atomic operations before this initialization.
221 return true;
222 #endif
223 }
224 static julong available_memory();
225 static julong physical_memory();
226 static bool has_allocatable_memory_limit(julong* limit);
227 static bool is_server_class_machine();
228
229 // number of CPUs
230 static int processor_count() {
231 return _processor_count;
232 }
233 static void set_processor_count(int count) { _processor_count = count; }
234
235 // Returns the number of CPUs this process is currently allowed to run on.
236 // Note that on some OSes this can change dynamically.
237 static int active_processor_count();
238
239 // Bind processes to processors.
240 // This is a two step procedure:
241 // first you generate a distribution of processes to processors,
242 // then you bind processes according to that distribution.
243 // Compute a distribution for number of processes to processors.
244 // Stores the processor id's into the distribution array argument.
245 // Returns true if it worked, false if it didn't.
246 static bool distribute_processes(uint length, uint* distribution);
247 // Binds the current process to a processor.
248 // Returns true if it worked, false if it didn't.
249 static bool bind_to_processor(uint processor_id);
250
251 // Give a name to the current thread.
252 static void set_native_thread_name(const char *name);
253
254 // Interface for stack banging (predetect possible stack overflow for
255 // exception processing) There are guard pages, and above that shadow
256 // pages for stack overflow checking.
257 static bool uses_stack_guard_pages();
258 static bool allocate_stack_guard_pages();
259 static void bang_stack_shadow_pages();
260 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
261
262 // OS interface to Virtual Memory
263
264 // Return the default page size.
265 static int vm_page_size();
266
267 // Return the page size to use for a region of memory. The min_pages argument
268 // is a hint intended to limit fragmentation; it says the returned page size
269 // should be <= region_max_size / min_pages. Because min_pages is a hint,
270 // this routine may return a size larger than region_max_size / min_pages.
271 //
272 // The current implementation ignores min_pages if a larger page size is an
273 // exact multiple of both region_min_size and region_max_size. This allows
274 // larger pages to be used when doing so would not cause fragmentation; in
275 // particular, a single page can be used when region_min_size ==
276 // region_max_size == a supported page size.
277 static size_t page_size_for_region(size_t region_min_size,
278 size_t region_max_size,
279 uint min_pages);
280 // Return the largest page size that can be used
281 static size_t max_page_size() {
282 // The _page_sizes array is sorted in descending order.
283 return _page_sizes[0];
284 }
285
286 // Methods for tracing page sizes returned by the above method; enabled by
287 // TracePageSizes. The region_{min,max}_size parameters should be the values
288 // passed to page_size_for_region() and page_size should be the result of that
289 // call. The (optional) base and size parameters should come from the
290 // ReservedSpace base() and size() methods.
291 static void trace_page_sizes(const char* str, const size_t* page_sizes,
292 int count) PRODUCT_RETURN;
293 static void trace_page_sizes(const char* str, const size_t region_min_size,
294 const size_t region_max_size,
295 const size_t page_size,
296 const char* base = NULL,
297 const size_t size = 0) PRODUCT_RETURN;
298
299 static int vm_allocation_granularity();
300 static char* reserve_memory(size_t bytes, char* addr = 0,
301 size_t alignment_hint = 0);
302 static char* reserve_memory(size_t bytes, char* addr,
303 size_t alignment_hint, MEMFLAGS flags);
304 static char* reserve_memory_aligned(size_t size, size_t alignment);
305 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
306 static void split_reserved_memory(char *base, size_t size,
307 size_t split, bool realloc);
308 static bool commit_memory(char* addr, size_t bytes, bool executable);
309 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
310 bool executable);
311 // Same as commit_memory() that either succeeds or calls
312 // vm_exit_out_of_memory() with the specified mesg.
313 static void commit_memory_or_exit(char* addr, size_t bytes,
314 bool executable, const char* mesg);
315 static void commit_memory_or_exit(char* addr, size_t size,
316 size_t alignment_hint,
317 bool executable, const char* mesg);
318 static bool uncommit_memory(char* addr, size_t bytes);
319 static bool release_memory(char* addr, size_t bytes);
320
321 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
322 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
323 bool is_committed = true);
324
325 static bool guard_memory(char* addr, size_t bytes);
326 static bool unguard_memory(char* addr, size_t bytes);
327 static bool create_stack_guard_pages(char* addr, size_t bytes);
328 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
329 static bool remove_stack_guard_pages(char* addr, size_t bytes);
330
331 static char* map_memory(int fd, const char* file_name, size_t file_offset,
332 char *addr, size_t bytes, bool read_only = false,
333 bool allow_exec = false);
334 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
335 char *addr, size_t bytes, bool read_only,
336 bool allow_exec);
337 static bool unmap_memory(char *addr, size_t bytes);
338 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
339 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
340
341 // NUMA-specific interface
342 static bool numa_has_static_binding();
343 static bool numa_has_group_homing();
344 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
345 static void numa_make_global(char *addr, size_t bytes);
346 static size_t numa_get_groups_num();
347 static size_t numa_get_leaf_groups(int *ids, size_t size);
348 static bool numa_topology_changed();
349 static int numa_get_group_id();
350
351 // Page manipulation
352 struct page_info {
353 size_t size;
354 int lgrp_id;
355 };
356 static bool get_page_info(char *start, page_info* info);
357 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
358
359 static char* non_memory_address_word();
360 // reserve, commit and pin the entire memory region
361 static char* reserve_memory_special(size_t size, size_t alignment,
362 char* addr, bool executable);
363 static bool release_memory_special(char* addr, size_t bytes);
364 static void large_page_init();
365 static size_t large_page_size();
366 static bool can_commit_large_page_memory();
367 static bool can_execute_large_page_memory();
368
369 // OS interface to polling page
370 static address get_polling_page() { return _polling_page; }
371 static void set_polling_page(address page) { _polling_page = page; }
372 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
373 static void make_polling_page_unreadable();
374 static void make_polling_page_readable();
375
376 // Routines used to serialize the thread state without using membars
377 static void serialize_thread_states();
378
379 // Since we write to the serialize page from every thread, we
380 // want stores to be on unique cache lines whenever possible
381 // in order to minimize CPU cross talk. We pre-compute the
382 // amount to shift the thread* to make this offset unique to
383 // each thread.
384 static int get_serialize_page_shift_count() {
385 return SerializePageShiftCount;
386 }
387
388 static void set_serialize_page_mask(uintptr_t mask) {
389 _serialize_page_mask = mask;
390 }
391
392 static unsigned int get_serialize_page_mask() {
393 return _serialize_page_mask;
394 }
395
396 static void set_memory_serialize_page(address page);
397
398 static address get_memory_serialize_page() {
399 return (address)_mem_serialize_page;
400 }
401
402 static inline void write_memory_serialize_page(JavaThread *thread) {
403 uintptr_t page_offset = ((uintptr_t)thread >>
404 get_serialize_page_shift_count()) &
405 get_serialize_page_mask();
406 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
407 }
408
409 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
410 if (UseMembar) return false;
411 // Previously this function calculated the exact address of this
412 // thread's serialize page, and checked if the faulting address
413 // was equal. However, some platforms mask off faulting addresses
414 // to the page size, so now we just check that the address is
415 // within the page. This makes the thread argument unnecessary,
416 // but we retain the NULL check to preserve existing behaviour.
417 if (thread == NULL) return false;
418 address page = (address) _mem_serialize_page;
419 return addr >= page && addr < (page + os::vm_page_size());
420 }
421
422 static void block_on_serialize_page_trap();
423
424 // threads
425
426 enum ThreadType {
427 vm_thread,
428 cgc_thread, // Concurrent GC thread
429 pgc_thread, // Parallel GC thread
430 java_thread,
431 compiler_thread,
432 watcher_thread,
433 os_thread
434 };
435
436 static bool create_thread(Thread* thread,
437 ThreadType thr_type,
438 size_t stack_size = 0);
439 static bool create_main_thread(JavaThread* thread);
440 static bool create_attached_thread(JavaThread* thread);
441 static void pd_start_thread(Thread* thread);
442 static void start_thread(Thread* thread);
443
444 static void initialize_thread(Thread* thr);
445 static void free_thread(OSThread* osthread);
446
447 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
448 static intx current_thread_id();
449 static int current_process_id();
450 static int sleep(Thread* thread, jlong ms, bool interruptable);
451 // Short standalone OS sleep suitable for slow path spin loop.
452 // Ignores Thread.interrupt() (so keep it short).
453 // ms = 0, will sleep for the least amount of time allowed by the OS.
454 static void naked_short_sleep(jlong ms);
455 static void infinite_sleep(); // never returns, use with CAUTION
456 static void yield(); // Yields to all threads with same priority
457 enum YieldResult {
458 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
459 YIELD_NONEREADY = 0, // No other runnable/ready threads.
460 // platform-specific yield return immediately
461 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
462 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
463 // yield that can be used in lieu of blocking.
464 } ;
465 static YieldResult NakedYield () ;
466 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
467 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
468 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
469 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
470
471 static void interrupt(Thread* thread);
472 static bool is_interrupted(Thread* thread, bool clear_interrupted);
473
474 static int pd_self_suspend_thread(Thread* thread);
475
476 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
477 static frame fetch_frame_from_context(void* ucVoid);
478
479 static ExtendedPC get_thread_pc(Thread *thread);
480 static void breakpoint();
481
482 static address current_stack_pointer();
483 static address current_stack_base();
484 static size_t current_stack_size();
485
486 static void verify_stack_alignment() PRODUCT_RETURN;
487
488 static int message_box(const char* title, const char* message);
489 static char* do_you_want_to_debug(const char* message);
490
491 // run cmd in a separate process and return its exit code; or -1 on failures
492 static int fork_and_exec(char *cmd);
493
494 // os::exit() is merged with vm_exit()
495 // static void exit(int num);
496
497 // Terminate the VM, but don't exit the process
498 static void shutdown();
499
500 // Terminate with an error. Default is to generate a core file on platforms
501 // that support such things. This calls shutdown() and then aborts.
502 static void abort(bool dump_core = true);
503
504 // Die immediately, no exit hook, no abort hook, no cleanup.
505 static void die();
506
507 // File i/o operations
508 static const int default_file_open_flags();
509 static int open(const char *path, int oflag, int mode);
510 static FILE* open(int fd, const char* mode);
511 static int close(int fd);
512 static jlong lseek(int fd, jlong offset, int whence);
513 static char* native_path(char *path);
514 static int ftruncate(int fd, jlong length);
515 static int fsync(int fd);
516 static int available(int fd, jlong *bytes);
517
518 //File i/o operations
519
520 static size_t read(int fd, void *buf, unsigned int nBytes);
521 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
522 static size_t write(int fd, const void *buf, unsigned int nBytes);
523
524 // Reading directories.
525 static DIR* opendir(const char* dirname);
526 static int readdir_buf_size(const char *path);
527 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
528 static int closedir(DIR* dirp);
529
530 // Dynamic library extension
531 static const char* dll_file_extension();
532
533 static const char* get_temp_directory();
534 static const char* get_current_directory(char *buf, size_t buflen);
535
536 // Builds a platform-specific full library path given a ld path and lib name
537 // Returns true if buffer contains full path to existing file, false otherwise
538 static bool dll_build_name(char* buffer, size_t size,
539 const char* pathname, const char* fname);
540
541 // Symbol lookup, find nearest function name; basically it implements
542 // dladdr() for all platforms. Name of the nearest function is copied
543 // to buf. Distance from its base address is optionally returned as offset.
544 // If function name is not found, buf[0] is set to '\0' and offset is
545 // set to -1 (if offset is non-NULL).
546 static bool dll_address_to_function_name(address addr, char* buf,
547 int buflen, int* offset);
548
549 // Locate DLL/DSO. On success, full path of the library is copied to
550 // buf, and offset is optionally set to be the distance between addr
551 // and the library's base address. On failure, buf[0] is set to '\0'
552 // and offset is set to -1 (if offset is non-NULL).
553 static bool dll_address_to_library_name(address addr, char* buf,
554 int buflen, int* offset);
555
556 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
557 static bool address_is_in_vm(address addr);
558
559 // Loads .dll/.so and
560 // in case of error it checks if .dll/.so was built for the
561 // same architecture as Hotspot is running on
562 static void* dll_load(const char *name, char *ebuf, int ebuflen);
563
564 // lookup symbol in a shared library
565 static void* dll_lookup(void* handle, const char* name);
566
567 // Unload library
568 static void dll_unload(void *lib);
569
570 // Return the handle of this process
571 static void* get_default_process_handle();
572
573 // Check for static linked agent library
574 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
575 size_t syms_len);
576
577 // Find agent entry point
578 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
579 const char *syms[], size_t syms_len);
580
581 // Print out system information; they are called by fatal error handler.
582 // Output format may be different on different platforms.
583 static void print_os_info(outputStream* st);
584 static void print_os_info_brief(outputStream* st);
585 static void print_cpu_info(outputStream* st);
586 static void pd_print_cpu_info(outputStream* st);
587 static void print_memory_info(outputStream* st);
588 static void print_dll_info(outputStream* st);
589 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
590 static void print_context(outputStream* st, void* context);
591 static void print_register_info(outputStream* st, void* context);
592 static void print_siginfo(outputStream* st, void* siginfo);
593 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
594 static void print_date_and_time(outputStream* st);
595
596 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
597 static size_t lasterror(char *buf, size_t len);
598 static int get_last_error();
599
600 // Determines whether the calling process is being debugged by a user-mode debugger.
601 static bool is_debugger_attached();
602
603 // wait for a key press if PauseAtExit is set
604 static void wait_for_keypress_at_exit(void);
605
606 // The following two functions are used by fatal error handler to trace
607 // native (C) frames. They are not part of frame.hpp/frame.cpp because
608 // frame.hpp/cpp assume thread is JavaThread, and also because different
609 // OS/compiler may have different convention or provide different API to
610 // walk C frames.
611 //
612 // We don't attempt to become a debugger, so we only follow frames if that
613 // does not require a lookup in the unwind table, which is part of the binary
614 // file but may be unsafe to read after a fatal error. So on x86, we can
615 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
616 // possible to walk C stack without having the unwind table.
617 static bool is_first_C_frame(frame *fr);
618 static frame get_sender_for_C_frame(frame *fr);
619
620 // return current frame. pc() and sp() are set to NULL on failure.
621 static frame current_frame();
622
623 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
624
625 // returns a string to describe the exception/signal;
626 // returns NULL if exception_code is not an OS exception/signal.
627 static const char* exception_name(int exception_code, char* buf, size_t buflen);
628
629 // Returns native Java library, loads if necessary
630 static void* native_java_library();
631
632 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
633 static void jvm_path(char *buf, jint buflen);
634
635 // Returns true if we are running in a headless jre.
636 static bool is_headless_jre();
637
638 // JNI names
639 static void print_jni_name_prefix_on(outputStream* st, int args_size);
640 static void print_jni_name_suffix_on(outputStream* st, int args_size);
641
642 // File conventions
643 static const char* file_separator();
644 static const char* line_separator();
645 static const char* path_separator();
646
647 // Init os specific system properties values
648 static void init_system_properties_values();
649
650 // IO operations, non-JVM_ version.
651 static int stat(const char* path, struct stat* sbuf);
652 static bool dir_is_empty(const char* path);
653
654 // IO operations on binary files
655 static int create_binary_file(const char* path, bool rewrite_existing);
656 static jlong current_file_offset(int fd);
657 static jlong seek_to_file_offset(int fd, jlong offset);
658
659 // Thread Local Storage
660 static int allocate_thread_local_storage();
661 static void thread_local_storage_at_put(int index, void* value);
662 static void* thread_local_storage_at(int index);
663 static void free_thread_local_storage(int index);
664
665 // Retrieve native stack frames.
666 // Parameter:
667 // stack: an array to storage stack pointers.
668 // frames: size of above array.
669 // toSkip: number of stack frames to skip at the beginning.
670 // Return: number of stack frames captured.
671 static int get_native_stack(address* stack, int size, int toSkip = 0);
672
673 // General allocation (must be MT-safe)
674 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
675 static void* malloc (size_t size, MEMFLAGS flags);
676 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
677 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
678
679 static void free (void *memblock, MEMFLAGS flags = mtNone);
680 static bool check_heap(bool force = false); // verify C heap integrity
681 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
682
683 #ifndef PRODUCT
684 static julong num_mallocs; // # of calls to malloc/realloc
685 static julong alloc_bytes; // # of bytes allocated
686 static julong num_frees; // # of calls to free
687 static julong free_bytes; // # of bytes freed
688 #endif
689
690 // SocketInterface (ex HPI SocketInterface )
691 static int socket(int domain, int type, int protocol);
692 static int socket_close(int fd);
693 static int socket_shutdown(int fd, int howto);
694 static int recv(int fd, char* buf, size_t nBytes, uint flags);
695 static int send(int fd, char* buf, size_t nBytes, uint flags);
696 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
697 static int timeout(int fd, long timeout);
698 static int listen(int fd, int count);
699 static int connect(int fd, struct sockaddr* him, socklen_t len);
700 static int bind(int fd, struct sockaddr* him, socklen_t len);
701 static int accept(int fd, struct sockaddr* him, socklen_t* len);
702 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
703 struct sockaddr* from, socklen_t* fromlen);
704 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
705 static int sendto(int fd, char* buf, size_t len, uint flags,
706 struct sockaddr* to, socklen_t tolen);
707 static int socket_available(int fd, jint* pbytes);
708
709 static int get_sock_opt(int fd, int level, int optname,
710 char* optval, socklen_t* optlen);
711 static int set_sock_opt(int fd, int level, int optname,
712 const char* optval, socklen_t optlen);
713 static int get_host_name(char* name, int namelen);
714
715 static struct hostent* get_host_by_name(char* name);
716
717 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
718 static void signal_init();
719 static void signal_init_pd();
720 static void signal_notify(int signal_number);
721 static void* signal(int signal_number, void* handler);
722 static void signal_raise(int signal_number);
723 static int signal_wait();
724 static int signal_lookup();
725 static void* user_handler();
726 static void terminate_signal_thread();
727 static int sigexitnum_pd();
728
729 // random number generation
730 static long random(); // return 32bit pseudorandom number
731 static void init_random(long initval); // initialize random sequence
732
733 // Structured OS Exception support
734 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
735
736 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
737 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
738
739 // Get the default path to the core file
740 // Returns the length of the string
741 static int get_core_path(char* buffer, size_t bufferSize);
742
743 // JVMTI & JVM monitoring and management support
744 // The thread_cpu_time() and current_thread_cpu_time() are only
745 // supported if is_thread_cpu_time_supported() returns true.
746 // They are not supported on Solaris T1.
747
748 // Thread CPU Time - return the fast estimate on a platform
749 // On Solaris - call gethrvtime (fast) - user time only
750 // On Linux - fast clock_gettime where available - user+sys
751 // - otherwise: very slow /proc fs - user+sys
752 // On Windows - GetThreadTimes - user+sys
753 static jlong current_thread_cpu_time();
754 static jlong thread_cpu_time(Thread* t);
755
756 // Thread CPU Time with user_sys_cpu_time parameter.
757 //
758 // If user_sys_cpu_time is true, user+sys time is returned.
759 // Otherwise, only user time is returned
760 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
761 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
762
763 // Return a bunch of info about the timers.
764 // Note that the returned info for these two functions may be different
765 // on some platforms
766 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
767 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
768
769 static bool is_thread_cpu_time_supported();
770
771 // System loadavg support. Returns -1 if load average cannot be obtained.
772 static int loadavg(double loadavg[], int nelem);
773
774 // Hook for os specific jvm options that we don't want to abort on seeing
775 static bool obsolete_option(const JavaVMOption *option);
776
777 // Extensions
778 #include "runtime/os_ext.hpp"
779
780 public:
781 class CrashProtectionCallback : public StackObj {
782 public:
783 virtual void call() = 0;
784 };
785
786 // Platform dependent stuff
787 #ifdef TARGET_OS_FAMILY_linux
788 # include "os_linux.hpp"
789 # include "os_posix.hpp"
790 #endif
791 #ifdef TARGET_OS_FAMILY_solaris
792 # include "os_solaris.hpp"
793 # include "os_posix.hpp"
794 #endif
795 #ifdef TARGET_OS_FAMILY_windows
796 # include "os_windows.hpp"
797 #endif
798 #ifdef TARGET_OS_FAMILY_aix
799 # include "os_aix.hpp"
800 # include "os_posix.hpp"
801 #endif
802 #ifdef TARGET_OS_FAMILY_bsd
803 # include "os_posix.hpp"
804 # include "os_bsd.hpp"
805 #endif
806 #ifdef TARGET_OS_ARCH_linux_x86
807 # include "os_linux_x86.hpp"
808 #endif
809 #ifdef TARGET_OS_ARCH_linux_sparc
810 # include "os_linux_sparc.hpp"
811 #endif
812 #ifdef TARGET_OS_ARCH_linux_zero
813 # include "os_linux_zero.hpp"
814 #endif
815 #ifdef TARGET_OS_ARCH_solaris_x86
816 # include "os_solaris_x86.hpp"
817 #endif
818 #ifdef TARGET_OS_ARCH_solaris_sparc
819 # include "os_solaris_sparc.hpp"
820 #endif
821 #ifdef TARGET_OS_ARCH_windows_x86
822 # include "os_windows_x86.hpp"
823 #endif
824 #ifdef TARGET_OS_ARCH_linux_arm
825 # include "os_linux_arm.hpp"
826 #endif
827 #ifdef TARGET_OS_ARCH_linux_ppc
828 # include "os_linux_ppc.hpp"
829 #endif
830 #ifdef TARGET_OS_ARCH_aix_ppc
831 # include "os_aix_ppc.hpp"
832 #endif
833 #ifdef TARGET_OS_ARCH_bsd_x86
834 # include "os_bsd_x86.hpp"
835 #endif
836 #ifdef TARGET_OS_ARCH_bsd_zero
837 # include "os_bsd_zero.hpp"
838 #endif
839
840 public:
841 #ifndef PLATFORM_PRINT_NATIVE_STACK
842 // No platform-specific code for printing the native stack.
843 static bool platform_print_native_stack(outputStream* st, void* context,
844 char *buf, int buf_size) {
845 return false;
846 }
847 #endif
848
849 // debugging support (mostly used by debug.cpp but also fatal error handler)
850 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
851
852 static bool dont_yield(); // when true, JVM_Yield() is nop
853 static void print_statistics();
854
855 // Thread priority helpers (implemented in OS-specific part)
856 static OSReturn set_native_priority(Thread* thread, int native_prio);
857 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
858 static int java_to_os_priority[CriticalPriority + 1];
859 // Hint to the underlying OS that a task switch would not be good.
860 // Void return because it's a hint and can fail.
861 static void hint_no_preempt();
862
863 // Used at creation if requested by the diagnostic flag PauseAtStartup.
864 // Causes the VM to wait until an external stimulus has been applied
865 // (for Unix, that stimulus is a signal, for Windows, an external
866 // ResumeThread call)
867 static void pause();
868
869 // Builds a platform dependent Agent_OnLoad_<libname> function name
870 // which is used to find statically linked in agents.
871 static char* build_agent_function_name(const char *sym, const char *cname,
872 bool is_absolute_path);
873
874 class SuspendedThreadTaskContext {
875 public:
876 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
877 Thread* thread() const { return _thread; }
878 void* ucontext() const { return _ucontext; }
879 private:
880 Thread* _thread;
881 void* _ucontext;
882 };
883
884 class SuspendedThreadTask {
885 public:
886 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
887 virtual ~SuspendedThreadTask() {}
888 void run();
889 bool is_done() { return _done; }
890 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
891 protected:
892 private:
893 void internal_do_task();
894 Thread* _thread;
895 bool _done;
896 };
897
898 #ifndef TARGET_OS_FAMILY_windows
899 // Suspend/resume support
900 // Protocol:
901 //
902 // a thread starts in SR_RUNNING
903 //
904 // SR_RUNNING can go to
905 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
906 // SR_SUSPEND_REQUEST can go to
907 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
908 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
909 // SR_SUSPENDED can go to
910 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
911 // SR_WAKEUP_REQUEST can go to
912 // * SR_RUNNING when the stopped thread receives the signal
913 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
914 class SuspendResume {
915 public:
916 enum State {
917 SR_RUNNING,
918 SR_SUSPEND_REQUEST,
919 SR_SUSPENDED,
920 SR_WAKEUP_REQUEST
921 };
922
923 private:
924 volatile State _state;
925
926 private:
927 /* try to switch state from state "from" to state "to"
928 * returns the state set after the method is complete
929 */
930 State switch_state(State from, State to);
931
932 public:
933 SuspendResume() : _state(SR_RUNNING) { }
934
935 State state() const { return _state; }
936
937 State request_suspend() {
938 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
939 }
940
941 State cancel_suspend() {
942 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
943 }
944
945 State suspended() {
946 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
947 }
948
949 State request_wakeup() {
950 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
951 }
952
953 State running() {
954 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
955 }
956
957 bool is_running() const {
958 return _state == SR_RUNNING;
959 }
960
961 bool is_suspend_request() const {
962 return _state == SR_SUSPEND_REQUEST;
963 }
964
965 bool is_suspended() const {
966 return _state == SR_SUSPENDED;
967 }
968 };
969 #endif
970
971
972 protected:
973 static long _rand_seed; // seed for random number generator
974 static int _processor_count; // number of processors
975
976 static char* format_boot_path(const char* format_string,
977 const char* home,
978 int home_len,
979 char fileSep,
980 char pathSep);
981 static bool set_boot_path(char fileSep, char pathSep);
982 static char** split_path(const char* path, int* n);
983
984 };
985
986 // Note that "PAUSE" is almost always used with synchronization
987 // so arguably we should provide Atomic::SpinPause() instead
988 // of the global SpinPause() with C linkage.
989 // It'd also be eligible for inlining on many platforms.
990
991 extern "C" int SpinPause();
992
993 #endif // SHARE_VM_RUNTIME_OS_HPP