1 /*
2 * Copyright (c) 1997, 2016, 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 "prims/jvm.h"
30 #include "runtime/extendedPC.hpp"
31 #include "runtime/handles.hpp"
32 #include "utilities/macros.hpp"
33 #ifndef _WINDOWS
34 # include <setjmp.h>
35 #endif
36 #ifdef __APPLE__
37 # include <mach/mach_time.h>
38 #endif
39
40 class AgentLibrary;
41
42 // os defines the interface to operating system; this includes traditional
43 // OS services (time, I/O) as well as other functionality with system-
44 // dependent code.
45
46 typedef void (*dll_func)(...);
47
48 class Thread;
49 class JavaThread;
50 class Event;
51 class DLL;
52 class FileHandle;
53 class NativeCallStack;
54
55 template<class E> class GrowableArray;
56
57 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
58
59 // Platform-independent error return values from OS functions
60 enum OSReturn {
61 OS_OK = 0, // Operation was successful
62 OS_ERR = -1, // Operation failed
63 OS_INTRPT = -2, // Operation was interrupted
64 OS_TIMEOUT = -3, // Operation timed out
65 OS_NOMEM = -5, // Operation failed for lack of memory
66 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
67 };
68
69 enum ThreadPriority { // JLS 20.20.1-3
70 NoPriority = -1, // Initial non-priority value
71 MinPriority = 1, // Minimum priority
72 NormPriority = 5, // Normal (non-daemon) priority
73 NearMaxPriority = 9, // High priority, used for VMThread
74 MaxPriority = 10, // Highest priority, used for WatcherThread
75 // ensures that VMThread doesn't starve profiler
76 CriticalPriority = 11 // Critical thread priority
77 };
78
79 // Executable parameter flag for os::commit_memory() and
80 // os::commit_memory_or_exit().
81 const bool ExecMem = true;
82
83 // Typedef for structured exception handling support
84 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
85
86 class MallocTracker;
87
88 class os: AllStatic {
89 friend class VMStructs;
90 friend class JVMCIVMStructs;
91 friend class MallocTracker;
92 public:
93 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
94
95 private:
96 static OSThread* _starting_thread;
97 static address _polling_page;
98 static volatile int32_t * _mem_serialize_page;
99 static uintptr_t _serialize_page_mask;
100 public:
101 static size_t _page_sizes[page_sizes_max];
102
103 private:
104 static void init_page_sizes(size_t default_page_size) {
105 _page_sizes[0] = default_page_size;
106 _page_sizes[1] = 0; // sentinel
107 }
108
109 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
110 size_t alignment_hint = 0);
111 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
112 static void pd_split_reserved_memory(char *base, size_t size,
113 size_t split, bool realloc);
114 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
115 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
116 bool executable);
117 // Same as pd_commit_memory() that either succeeds or calls
118 // vm_exit_out_of_memory() with the specified mesg.
119 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
120 bool executable, const char* mesg);
121 static void pd_commit_memory_or_exit(char* addr, size_t size,
122 size_t alignment_hint,
123 bool executable, const char* mesg);
124 static bool pd_uncommit_memory(char* addr, size_t bytes);
125 static bool pd_release_memory(char* addr, size_t bytes);
126
127 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
128 char *addr, size_t bytes, bool read_only = false,
129 bool allow_exec = false);
130 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
131 char *addr, size_t bytes, bool read_only,
132 bool allow_exec);
133 static bool pd_unmap_memory(char *addr, size_t bytes);
134 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
135 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
136
137 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
138
139 // Get summary strings for system information in buffer provided
140 static void get_summary_cpu_info(char* buf, size_t buflen);
141 static void get_summary_os_info(char* buf, size_t buflen);
142
143 public:
144 static void init(void); // Called before command line parsing
145 static void init_before_ergo(void); // Called after command line parsing
146 // before VM ergonomics processing.
147 static jint init_2(void); // Called after command line parsing
148 // and VM ergonomics processing
149 static void init_globals(void) { // Called from init_globals() in init.cpp
150 init_globals_ext();
151 }
152
153 // File names are case-insensitive on windows only
154 // Override me as needed
155 static int file_name_strcmp(const char* s1, const char* s2);
156
157 // unset environment variable
158 static bool unsetenv(const char* name);
159
160 static bool have_special_privileges();
161
162 static jlong javaTimeMillis();
163 static jlong javaTimeNanos();
164 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
165 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
166 static void run_periodic_checks();
167 static bool supports_monotonic_clock();
168
169 // Returns the elapsed time in seconds since the vm started.
170 static double elapsedTime();
171
172 // Returns real time in seconds since an arbitrary point
173 // in the past.
174 static bool getTimesSecs(double* process_real_time,
175 double* process_user_time,
176 double* process_system_time);
177
178 // Interface to the performance counter
179 static jlong elapsed_counter();
180 static jlong elapsed_frequency();
181
182 // The "virtual time" of a thread is the amount of time a thread has
183 // actually run. The first function indicates whether the OS supports
184 // this functionality for the current thread, and if so:
185 // * the second enables vtime tracking (if that is required).
186 // * the third tells whether vtime is enabled.
187 // * the fourth returns the elapsed virtual time for the current
188 // thread.
189 static bool supports_vtime();
190 static bool enable_vtime();
191 static bool vtime_enabled();
192 static double elapsedVTime();
193
194 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
195 // It is MT safe, but not async-safe, as reading time zone
196 // information may require a lock on some platforms.
197 static char* local_time_string(char *buf, size_t buflen);
198 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
199 // Fill in buffer with current local time as an ISO-8601 string.
200 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
201 // Returns buffer, or NULL if it failed.
202 static char* iso8601_time(char* buffer, size_t buffer_length);
203
204 // Interface for detecting multiprocessor system
205 static inline bool is_MP() {
206 // During bootstrap if _processor_count is not yet initialized
207 // we claim to be MP as that is safest. If any platform has a
208 // stub generator that might be triggered in this phase and for
209 // which being declared MP when in fact not, is a problem - then
210 // the bootstrap routine for the stub generator needs to check
211 // the processor count directly and leave the bootstrap routine
212 // in place until called after initialization has ocurred.
213 return (_processor_count != 1) || AssumeMP;
214 }
215 static julong available_memory();
216 static julong physical_memory();
217 static bool has_allocatable_memory_limit(julong* limit);
218 static bool is_server_class_machine();
219
220 // number of CPUs
221 static int processor_count() {
222 return _processor_count;
223 }
224 static void set_processor_count(int count) { _processor_count = count; }
225
226 // Returns the number of CPUs this process is currently allowed to run on.
227 // Note that on some OSes this can change dynamically.
228 static int active_processor_count();
229
230 // Bind processes to processors.
231 // This is a two step procedure:
232 // first you generate a distribution of processes to processors,
233 // then you bind processes according to that distribution.
234 // Compute a distribution for number of processes to processors.
235 // Stores the processor id's into the distribution array argument.
236 // Returns true if it worked, false if it didn't.
237 static bool distribute_processes(uint length, uint* distribution);
238 // Binds the current process to a processor.
239 // Returns true if it worked, false if it didn't.
240 static bool bind_to_processor(uint processor_id);
241
242 // Give a name to the current thread.
243 static void set_native_thread_name(const char *name);
244
245 // Interface for stack banging (predetect possible stack overflow for
246 // exception processing) There are guard pages, and above that shadow
247 // pages for stack overflow checking.
248 static bool uses_stack_guard_pages();
249 static bool must_commit_stack_guard_pages();
250 static void map_stack_shadow_pages(address sp);
251 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
252
253 // OS interface to Virtual Memory
254
255 // Return the default page size.
256 static int vm_page_size();
257
258 // Returns the page size to use for a region of memory.
259 // region_size / min_pages will always be greater than or equal to the
260 // returned value. The returned value will divide region_size.
261 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
262
263 // Returns the page size to use for a region of memory.
264 // region_size / min_pages will always be greater than or equal to the
265 // returned value. The returned value might not divide region_size.
266 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
267
268 // Return the largest page size that can be used
269 static size_t max_page_size() {
270 // The _page_sizes array is sorted in descending order.
271 return _page_sizes[0];
272 }
273
274 // Methods for tracing page sizes returned by the above method.
275 // The region_{min,max}_size parameters should be the values
276 // passed to page_size_for_region() and page_size should be the result of that
277 // call. The (optional) base and size parameters should come from the
278 // ReservedSpace base() and size() methods.
279 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
280 static void trace_page_sizes(const char* str,
281 const size_t region_min_size,
282 const size_t region_max_size,
283 const size_t page_size,
284 const char* base,
285 const size_t size);
286 static void trace_page_sizes_for_requested_size(const char* str,
287 const size_t requested_size,
288 const size_t page_size,
289 const size_t alignment,
290 const char* base,
291 const size_t size);
292
293 static int vm_allocation_granularity();
294 static char* reserve_memory(size_t bytes, char* addr = 0,
295 size_t alignment_hint = 0);
296 static char* reserve_memory(size_t bytes, char* addr,
297 size_t alignment_hint, MEMFLAGS flags);
298 static char* reserve_memory_aligned(size_t size, size_t alignment);
299 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
300 static void split_reserved_memory(char *base, size_t size,
301 size_t split, bool realloc);
302 static bool commit_memory(char* addr, size_t bytes, bool executable);
303 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
304 bool executable);
305 // Same as commit_memory() that either succeeds or calls
306 // vm_exit_out_of_memory() with the specified mesg.
307 static void commit_memory_or_exit(char* addr, size_t bytes,
308 bool executable, const char* mesg);
309 static void commit_memory_or_exit(char* addr, size_t size,
310 size_t alignment_hint,
311 bool executable, const char* mesg);
312 static bool uncommit_memory(char* addr, size_t bytes);
313 static bool release_memory(char* addr, size_t bytes);
314
315 // Touch memory pages that cover the memory range from start to end (exclusive)
316 // to make the OS back the memory range with actual memory.
317 // Current implementation may not touch the last page if unaligned addresses
318 // are passed.
319 static void pretouch_memory(void* start, void* end);
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 behavior.
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 naked_yield () ;
457 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
458 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
459
460 static void interrupt(Thread* thread);
461 static bool is_interrupted(Thread* thread, bool clear_interrupted);
462
463 static int pd_self_suspend_thread(Thread* thread);
464
465 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
466 static frame fetch_frame_from_context(const void* ucVoid);
467 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
468
469 static ExtendedPC get_thread_pc(Thread *thread);
470 static void breakpoint();
471 static bool start_debugging(char *buf, int buflen);
472
473 static address current_stack_pointer();
474 static address current_stack_base();
475 static size_t current_stack_size();
476
477 static void verify_stack_alignment() PRODUCT_RETURN;
478
479 static bool message_box(const char* title, const char* message);
480 static char* do_you_want_to_debug(const char* message);
481
482 // run cmd in a separate process and return its exit code; or -1 on failures
483 static int fork_and_exec(char *cmd);
484
485 // Call ::exit() on all platforms but Windows
486 static void exit(int num);
487
488 // Terminate the VM, but don't exit the process
489 static void shutdown();
490
491 // Terminate with an error. Default is to generate a core file on platforms
492 // that support such things. This calls shutdown() and then aborts.
493 static void abort(bool dump_core, void *siginfo, const void *context);
494 static void abort(bool dump_core = true);
495
496 // Die immediately, no exit hook, no abort hook, no cleanup.
497 static void die();
498
499 // File i/o operations
500 static const int default_file_open_flags();
501 static int open(const char *path, int oflag, int mode);
502 static FILE* open(int fd, const char* mode);
503 static int close(int fd);
504 static jlong lseek(int fd, jlong offset, int whence);
505 static char* native_path(char *path);
506 static int ftruncate(int fd, jlong length);
507 static int fsync(int fd);
508 static int available(int fd, jlong *bytes);
509 static int get_fileno(FILE* fp);
510 static void flockfile(FILE* fp);
511 static void funlockfile(FILE* fp);
512
513 static int compare_file_modified_times(const char* file1, const char* file2);
514
515 //File i/o operations
516
517 static size_t read(int fd, void *buf, unsigned int nBytes);
518 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
519 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
520 static size_t write(int fd, const void *buf, unsigned int nBytes);
521
522 // Reading directories.
523 static DIR* opendir(const char* dirname);
524 static int readdir_buf_size(const char *path);
525 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
526 static int closedir(DIR* dirp);
527
528 // Dynamic library extension
529 static const char* dll_file_extension();
530
531 static const char* get_temp_directory();
532 static const char* get_current_directory(char *buf, size_t buflen);
533
534 // Builds a platform-specific full library path given a ld path and lib name
535 // Returns true if buffer contains full path to existing file, false otherwise
536 static bool dll_build_name(char* buffer, size_t size,
537 const char* pathname, const char* fname);
538
539 // Symbol lookup, find nearest function name; basically it implements
540 // dladdr() for all platforms. Name of the nearest function is copied
541 // to buf. Distance from its base address is optionally returned as offset.
542 // If function name is not found, buf[0] is set to '\0' and offset is
543 // set to -1 (if offset is non-NULL).
544 static bool dll_address_to_function_name(address addr, char* buf,
545 int buflen, int* offset,
546 bool demangle = true);
547
548 // Locate DLL/DSO. On success, full path of the library is copied to
549 // buf, and offset is optionally set to be the distance between addr
550 // and the library's base address. On failure, buf[0] is set to '\0'
551 // and offset is set to -1 (if offset is non-NULL).
552 static bool dll_address_to_library_name(address addr, char* buf,
553 int buflen, int* offset);
554
555 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
556 static bool address_is_in_vm(address addr);
557
558 // Loads .dll/.so and
559 // in case of error it checks if .dll/.so was built for the
560 // same architecture as HotSpot is running on
561 static void* dll_load(const char *name, char *ebuf, int ebuflen);
562
563 // lookup symbol in a shared library
564 static void* dll_lookup(void* handle, const char* name);
565
566 // Unload library
567 static void dll_unload(void *lib);
568
569 // Callback for loaded module information
570 // Input parameters:
571 // char* module_file_name,
572 // address module_base_addr,
573 // address module_top_addr,
574 // void* param
575 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
576
577 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
578
579 // Return the handle of this process
580 static void* get_default_process_handle();
581
582 // Check for static linked agent library
583 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
584 size_t syms_len);
585
586 // Find agent entry point
587 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
588 const char *syms[], size_t syms_len);
589
590 // Write to stream
591 static int log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
592
593 // Get host name in buffer provided
594 static bool get_host_name(char* buf, size_t buflen);
595
596 // Print out system information; they are called by fatal error handler.
597 // Output format may be different on different platforms.
598 static void print_os_info(outputStream* st);
599 static void print_os_info_brief(outputStream* st);
600 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
601 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
602 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
603 static void print_memory_info(outputStream* st);
604 static void print_dll_info(outputStream* st);
605 static void print_environment_variables(outputStream* st, const char** env_list);
606 static void print_context(outputStream* st, const void* context);
607 static void print_register_info(outputStream* st, const void* context);
608 static void print_siginfo(outputStream* st, const void* siginfo);
609 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
610 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
611
612 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
613 static size_t lasterror(char *buf, size_t len);
614 static int get_last_error();
615
616 // Replacement for strerror().
617 // Will return the english description of the error (e.g. "File not found", as
618 // suggested in the POSIX standard.
619 // Will return "Unknown error" for an unknown errno value.
620 // Will not attempt to localize the returned string.
621 // Will always return a valid string which is a static constant.
622 // Will not change the value of errno.
623 static const char* strerror(int e);
624
625 // Will return the literalized version of the given errno (e.g. "EINVAL"
626 // for EINVAL).
627 // Will return "Unknown error" for an unknown errno value.
628 // Will always return a valid string which is a static constant.
629 // Will not change the value of errno.
630 static const char* errno_name(int e);
631
632 // Determines whether the calling process is being debugged by a user-mode debugger.
633 static bool is_debugger_attached();
634
635 // wait for a key press if PauseAtExit is set
636 static void wait_for_keypress_at_exit(void);
637
638 // The following two functions are used by fatal error handler to trace
639 // native (C) frames. They are not part of frame.hpp/frame.cpp because
640 // frame.hpp/cpp assume thread is JavaThread, and also because different
641 // OS/compiler may have different convention or provide different API to
642 // walk C frames.
643 //
644 // We don't attempt to become a debugger, so we only follow frames if that
645 // does not require a lookup in the unwind table, which is part of the binary
646 // file but may be unsafe to read after a fatal error. So on x86, we can
647 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
648 // possible to walk C stack without having the unwind table.
649 static bool is_first_C_frame(frame *fr);
650 static frame get_sender_for_C_frame(frame *fr);
651
652 // return current frame. pc() and sp() are set to NULL on failure.
653 static frame current_frame();
654
655 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
656
657 // returns a string to describe the exception/signal;
658 // returns NULL if exception_code is not an OS exception/signal.
659 static const char* exception_name(int exception_code, char* buf, size_t buflen);
660
661 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
662 static int get_signal_number(const char* signal_name);
663
664 // Returns native Java library, loads if necessary
665 static void* native_java_library();
666
667 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
668 static void jvm_path(char *buf, jint buflen);
669
670 // Returns true if we are running in a headless jre.
671 static bool is_headless_jre();
672
673 // JNI names
674 static void print_jni_name_prefix_on(outputStream* st, int args_size);
675 static void print_jni_name_suffix_on(outputStream* st, int args_size);
676
677 // Init os specific system properties values
678 static void init_system_properties_values();
679
680 // IO operations, non-JVM_ version.
681 static int stat(const char* path, struct stat* sbuf);
682 static bool dir_is_empty(const char* path);
683
684 // IO operations on binary files
685 static int create_binary_file(const char* path, bool rewrite_existing);
686 static jlong current_file_offset(int fd);
687 static jlong seek_to_file_offset(int fd, jlong offset);
688
689 // Retrieve native stack frames.
690 // Parameter:
691 // stack: an array to storage stack pointers.
692 // frames: size of above array.
693 // toSkip: number of stack frames to skip at the beginning.
694 // Return: number of stack frames captured.
695 static int get_native_stack(address* stack, int size, int toSkip = 0);
696
697 // General allocation (must be MT-safe)
698 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
699 static void* malloc (size_t size, MEMFLAGS flags);
700 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
701 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
702
703 static void free (void *memblock);
704 static bool check_heap(bool force = false); // verify C heap integrity
705 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
706 // Like strdup, but exit VM when strdup() returns NULL
707 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
708
709 #ifndef PRODUCT
710 static julong num_mallocs; // # of calls to malloc/realloc
711 static julong alloc_bytes; // # of bytes allocated
712 static julong num_frees; // # of calls to free
713 static julong free_bytes; // # of bytes freed
714 #endif
715
716 // SocketInterface (ex HPI SocketInterface )
717 static int socket(int domain, int type, int protocol);
718 static int socket_close(int fd);
719 static int recv(int fd, char* buf, size_t nBytes, uint flags);
720 static int send(int fd, char* buf, size_t nBytes, uint flags);
721 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
722 static int connect(int fd, struct sockaddr* him, socklen_t len);
723 static struct hostent* get_host_by_name(char* name);
724
725 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
726 static void signal_init();
727 static void signal_init_pd();
728 static void signal_notify(int signal_number);
729 static void* signal(int signal_number, void* handler);
730 static void signal_raise(int signal_number);
731 static int signal_wait();
732 static int signal_lookup();
733 static void* user_handler();
734 static void terminate_signal_thread();
735 static int sigexitnum_pd();
736
737 // random number generation
738 static long random(); // return 32bit pseudorandom number
739 static void init_random(long initval); // initialize random sequence
740
741 // Structured OS Exception support
742 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
743
744 // On Posix compatible OS it will simply check core dump limits while on Windows
745 // it will check if dump file can be created. Check or prepare a core dump to be
746 // taken at a later point in the same thread in os::abort(). Use the caller
747 // provided buffer as a scratch buffer. The status message which will be written
748 // into the error log either is file location or a short error message, depending
749 // on the checking result.
750 static void check_dump_limit(char* buffer, size_t bufferSize);
751
752 // Get the default path to the core file
753 // Returns the length of the string
754 static int get_core_path(char* buffer, size_t bufferSize);
755
756 // JVMTI & JVM monitoring and management support
757 // The thread_cpu_time() and current_thread_cpu_time() are only
758 // supported if is_thread_cpu_time_supported() returns true.
759 // They are not supported on Solaris T1.
760
761 // Thread CPU Time - return the fast estimate on a platform
762 // On Solaris - call gethrvtime (fast) - user time only
763 // On Linux - fast clock_gettime where available - user+sys
764 // - otherwise: very slow /proc fs - user+sys
765 // On Windows - GetThreadTimes - user+sys
766 static jlong current_thread_cpu_time();
767 static jlong thread_cpu_time(Thread* t);
768
769 // Thread CPU Time with user_sys_cpu_time parameter.
770 //
771 // If user_sys_cpu_time is true, user+sys time is returned.
772 // Otherwise, only user time is returned
773 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
774 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
775
776 // Return a bunch of info about the timers.
777 // Note that the returned info for these two functions may be different
778 // on some platforms
779 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
780 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
781
782 static bool is_thread_cpu_time_supported();
783
784 // System loadavg support. Returns -1 if load average cannot be obtained.
785 static int loadavg(double loadavg[], int nelem);
786
787 // Hook for os specific jvm options that we don't want to abort on seeing
788 static bool obsolete_option(const JavaVMOption *option);
789
790 // Amount beyond the callee frame size that we bang the stack.
791 static int extra_bang_size_in_bytes();
792
793 static char** split_path(const char* path, int* n);
794
795 // Extensions
796 #include "runtime/os_ext.hpp"
797
798 public:
799 class CrashProtectionCallback : public StackObj {
800 public:
801 virtual void call() = 0;
802 };
803
804 // Platform dependent stuff
805 #ifndef _WINDOWS
806 # include "os_posix.hpp"
807 #endif
808 #include OS_CPU_HEADER(os)
809 #include OS_HEADER(os)
810
811 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
812 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
813 #endif
814
815 public:
816 #ifndef PLATFORM_PRINT_NATIVE_STACK
817 // No platform-specific code for printing the native stack.
818 static bool platform_print_native_stack(outputStream* st, const void* context,
819 char *buf, int buf_size) {
820 return false;
821 }
822 #endif
823
824 // debugging support (mostly used by debug.cpp but also fatal error handler)
825 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
826
827 static bool dont_yield(); // when true, JVM_Yield() is nop
828 static void print_statistics();
829
830 // Thread priority helpers (implemented in OS-specific part)
831 static OSReturn set_native_priority(Thread* thread, int native_prio);
832 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
833 static int java_to_os_priority[CriticalPriority + 1];
834 // Hint to the underlying OS that a task switch would not be good.
835 // Void return because it's a hint and can fail.
836 static void hint_no_preempt();
837 static const char* native_thread_creation_failed_msg() {
838 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
839 }
840
841 // Used at creation if requested by the diagnostic flag PauseAtStartup.
842 // Causes the VM to wait until an external stimulus has been applied
843 // (for Unix, that stimulus is a signal, for Windows, an external
844 // ResumeThread call)
845 static void pause();
846
847 // Builds a platform dependent Agent_OnLoad_<libname> function name
848 // which is used to find statically linked in agents.
849 static char* build_agent_function_name(const char *sym, const char *cname,
850 bool is_absolute_path);
851
852 class SuspendedThreadTaskContext {
853 public:
854 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
855 Thread* thread() const { return _thread; }
856 void* ucontext() const { return _ucontext; }
857 private:
858 Thread* _thread;
859 void* _ucontext;
860 };
861
862 class SuspendedThreadTask {
863 public:
864 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
865 virtual ~SuspendedThreadTask() {}
866 void run();
867 bool is_done() { return _done; }
868 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
869 protected:
870 private:
871 void internal_do_task();
872 Thread* _thread;
873 bool _done;
874 };
875
876 #ifndef _WINDOWS
877 // Suspend/resume support
878 // Protocol:
879 //
880 // a thread starts in SR_RUNNING
881 //
882 // SR_RUNNING can go to
883 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
884 // SR_SUSPEND_REQUEST can go to
885 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
886 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
887 // SR_SUSPENDED can go to
888 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
889 // SR_WAKEUP_REQUEST can go to
890 // * SR_RUNNING when the stopped thread receives the signal
891 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
892 class SuspendResume {
893 public:
894 enum State {
895 SR_RUNNING,
896 SR_SUSPEND_REQUEST,
897 SR_SUSPENDED,
898 SR_WAKEUP_REQUEST
899 };
900
901 private:
902 volatile State _state;
903
904 private:
905 /* try to switch state from state "from" to state "to"
906 * returns the state set after the method is complete
907 */
908 State switch_state(State from, State to);
909
910 public:
911 SuspendResume() : _state(SR_RUNNING) { }
912
913 State state() const { return _state; }
914
915 State request_suspend() {
916 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
917 }
918
919 State cancel_suspend() {
920 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
921 }
922
923 State suspended() {
924 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
925 }
926
927 State request_wakeup() {
928 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
929 }
930
931 State running() {
932 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
933 }
934
935 bool is_running() const {
936 return _state == SR_RUNNING;
937 }
938
939 bool is_suspend_request() const {
940 return _state == SR_SUSPEND_REQUEST;
941 }
942
943 bool is_suspended() const {
944 return _state == SR_SUSPENDED;
945 }
946 };
947 #endif // !WINDOWS
948
949
950 protected:
951 static long _rand_seed; // seed for random number generator
952 static int _processor_count; // number of processors
953
954 static char* format_boot_path(const char* format_string,
955 const char* home,
956 int home_len,
957 char fileSep,
958 char pathSep);
959 static bool set_boot_path(char fileSep, char pathSep);
960
961 };
962
963 // Note that "PAUSE" is almost always used with synchronization
964 // so arguably we should provide Atomic::SpinPause() instead
965 // of the global SpinPause() with C linkage.
966 // It'd also be eligible for inlining on many platforms.
967
968 extern "C" int SpinPause();
969
970 #endif // SHARE_VM_RUNTIME_OS_HPP