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, int file_desc = -1);
111 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1);
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 static void initialize_initial_active_processor_count();
144 public:
145 static void init(void); // Called before command line parsing
146 static void init_before_ergo(void); // Called after command line parsing
147 // before VM ergonomics processing.
148 static jint init_2(void); // Called after command line parsing
149 // and VM ergonomics processing
150 static void init_globals(void) { // Called from init_globals() in init.cpp
151 init_globals_ext();
152 }
153
154 // File names are case-insensitive on windows only
155 // Override me as needed
156 static int file_name_strcmp(const char* s1, const char* s2);
157
158 // unset environment variable
159 static bool unsetenv(const char* name);
160
161 static bool have_special_privileges();
162
163 static jlong javaTimeMillis();
164 static jlong javaTimeNanos();
165 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
166 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
167 static void run_periodic_checks();
168 static bool supports_monotonic_clock();
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 static struct tm* gmtime_pd (const time_t* clock, struct tm* res);
201 // Fill in buffer with current local time as an ISO-8601 string.
202 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
203 // Returns buffer, or NULL if it failed.
204 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false);
205
206 // Interface for detecting multiprocessor system
207 static inline bool is_MP() {
208 // During bootstrap if _processor_count is not yet initialized
209 // we claim to be MP as that is safest. If any platform has a
210 // stub generator that might be triggered in this phase and for
211 // which being declared MP when in fact not, is a problem - then
212 // the bootstrap routine for the stub generator needs to check
213 // the processor count directly and leave the bootstrap routine
214 // in place until called after initialization has ocurred.
215 return (_processor_count != 1) || AssumeMP;
216 }
217 static julong available_memory();
218 static julong physical_memory();
219 static bool has_allocatable_memory_limit(julong* limit);
220 static bool is_server_class_machine();
221
222 // number of CPUs
223 static int processor_count() {
224 return _processor_count;
225 }
226 static void set_processor_count(int count) { _processor_count = count; }
227
228 // Returns the number of CPUs this process is currently allowed to run on.
229 // Note that on some OSes this can change dynamically.
230 static int active_processor_count();
231
232 // At startup the number of active CPUs this process is allowed to run on.
233 // This value does not change dynamically. May be different from active_processor_count().
234 static int initial_active_processor_count() {
235 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
236 return _initial_active_processor_count;
237 }
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 must_commit_stack_guard_pages();
259 static void map_stack_shadow_pages(address sp);
260 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
261
262 // OS interface to Virtual Memory
263
264 // Return the default page size.
265 static int vm_page_size();
266
267 // Returns the page size to use for a region of memory.
268 // region_size / min_pages will always be greater than or equal to the
269 // returned value. The returned value will divide region_size.
270 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
271
272 // Returns the page size to use for a region of memory.
273 // region_size / min_pages will always be greater than or equal to the
274 // returned value. The returned value might not divide region_size.
275 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
276
277 // Return the largest page size that can be used
278 static size_t max_page_size() {
279 // The _page_sizes array is sorted in descending order.
280 return _page_sizes[0];
281 }
282
283 // Methods for tracing page sizes returned by the above method.
284 // The region_{min,max}_size parameters should be the values
285 // passed to page_size_for_region() and page_size should be the result of that
286 // call. The (optional) base and size parameters should come from the
287 // ReservedSpace base() and size() methods.
288 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
289 static void trace_page_sizes(const char* str,
290 const size_t region_min_size,
291 const size_t region_max_size,
292 const size_t page_size,
293 const char* base,
294 const size_t size);
295 static void trace_page_sizes_for_requested_size(const char* str,
296 const size_t requested_size,
297 const size_t page_size,
298 const size_t alignment,
299 const char* base,
300 const size_t size);
301
302 static int vm_allocation_granularity();
303 static char* reserve_memory(size_t bytes, char* addr = 0,
304 size_t alignment_hint = 0, int file_desc = -1);
305 static char* reserve_memory(size_t bytes, char* addr,
306 size_t alignment_hint, MEMFLAGS flags);
307 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1);
308 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1);
309
310 static void split_reserved_memory(char *base, size_t size,
311 size_t split, bool realloc);
312 static bool commit_memory(char* addr, size_t bytes, bool executable);
313 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
314 bool executable);
315 // Same as commit_memory() that either succeeds or calls
316 // vm_exit_out_of_memory() with the specified mesg.
317 static void commit_memory_or_exit(char* addr, size_t bytes,
318 bool executable, const char* mesg);
319 static void commit_memory_or_exit(char* addr, size_t size,
320 size_t alignment_hint,
321 bool executable, const char* mesg);
322 static bool uncommit_memory(char* addr, size_t bytes);
323 static bool release_memory(char* addr, size_t bytes);
324
325 // Touch memory pages that cover the memory range from start to end (exclusive)
326 // to make the OS back the memory range with actual memory.
327 // Current implementation may not touch the last page if unaligned addresses
328 // are passed.
329 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
330
331 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
332 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
333 bool is_committed = true);
334
335 static bool guard_memory(char* addr, size_t bytes);
336 static bool unguard_memory(char* addr, size_t bytes);
337 static bool create_stack_guard_pages(char* addr, size_t bytes);
338 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
339 static bool remove_stack_guard_pages(char* addr, size_t bytes);
340
341 // Map the given address to the file descriptor.
342 static char* map_memory_to_file(char* base, size_t size, int fd);
343
344 // Helper function to create a new file with template jvmheap.XXXXXX
345 static int create_file_for_heap(const char* dir, size_t size);
346
347 static char* map_memory(int fd, const char* file_name, size_t file_offset,
348 char *addr, size_t bytes, bool read_only = false,
349 bool allow_exec = false);
350 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
351 char *addr, size_t bytes, bool read_only,
352 bool allow_exec);
353 static bool unmap_memory(char *addr, size_t bytes);
354 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
355 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
356
357 // NUMA-specific interface
358 static bool numa_has_static_binding();
359 static bool numa_has_group_homing();
360 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
361 static void numa_make_global(char *addr, size_t bytes);
362 static size_t numa_get_groups_num();
363 static size_t numa_get_leaf_groups(int *ids, size_t size);
364 static bool numa_topology_changed();
365 static int numa_get_group_id();
366
367 // Page manipulation
368 struct page_info {
369 size_t size;
370 int lgrp_id;
371 };
372 static bool get_page_info(char *start, page_info* info);
373 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
374
375 static char* non_memory_address_word();
376 // reserve, commit and pin the entire memory region
377 static char* reserve_memory_special(size_t size, size_t alignment,
378 char* addr, bool executable);
379 static bool release_memory_special(char* addr, size_t bytes);
380 static void large_page_init();
381 static size_t large_page_size();
382 static bool can_commit_large_page_memory();
383 static bool can_execute_large_page_memory();
384
385 // OS interface to polling page
386 static address get_polling_page() { return _polling_page; }
387 static void set_polling_page(address page) { _polling_page = page; }
388 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
389 static void make_polling_page_unreadable();
390 static void make_polling_page_readable();
391
392 // Routines used to serialize the thread state without using membars
393 static void serialize_thread_states();
394
395 // Since we write to the serialize page from every thread, we
396 // want stores to be on unique cache lines whenever possible
397 // in order to minimize CPU cross talk. We pre-compute the
398 // amount to shift the thread* to make this offset unique to
399 // each thread.
400 static int get_serialize_page_shift_count() {
401 return SerializePageShiftCount;
402 }
403
404 static void set_serialize_page_mask(uintptr_t mask) {
405 _serialize_page_mask = mask;
406 }
407
408 static unsigned int get_serialize_page_mask() {
409 return _serialize_page_mask;
410 }
411
412 static void set_memory_serialize_page(address page);
413
414 static address get_memory_serialize_page() {
415 return (address)_mem_serialize_page;
416 }
417
418 static inline void write_memory_serialize_page(JavaThread *thread) {
419 uintptr_t page_offset = ((uintptr_t)thread >>
420 get_serialize_page_shift_count()) &
421 get_serialize_page_mask();
422 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
423 }
424
425 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
426 if (UseMembar) return false;
427 // Previously this function calculated the exact address of this
428 // thread's serialize page, and checked if the faulting address
429 // was equal. However, some platforms mask off faulting addresses
430 // to the page size, so now we just check that the address is
431 // within the page. This makes the thread argument unnecessary,
432 // but we retain the NULL check to preserve existing behavior.
433 if (thread == NULL) return false;
434 address page = (address) _mem_serialize_page;
435 return addr >= page && addr < (page + os::vm_page_size());
436 }
437
438 static void block_on_serialize_page_trap();
439
440 // threads
441
442 enum ThreadType {
443 vm_thread,
444 cgc_thread, // Concurrent GC thread
445 pgc_thread, // Parallel GC thread
446 java_thread,
447 compiler_thread,
448 watcher_thread,
449 os_thread
450 };
451
452 static bool create_thread(Thread* thread,
453 ThreadType thr_type,
454 size_t req_stack_size = 0);
455 static bool create_main_thread(JavaThread* thread);
456 static bool create_attached_thread(JavaThread* thread);
457 static void pd_start_thread(Thread* thread);
458 static void start_thread(Thread* thread);
459
460 static void initialize_thread(Thread* thr);
461 static void free_thread(OSThread* osthread);
462
463 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
464 static intx current_thread_id();
465 static int current_process_id();
466 static int sleep(Thread* thread, jlong ms, bool interruptable);
467 // Short standalone OS sleep suitable for slow path spin loop.
468 // Ignores Thread.interrupt() (so keep it short).
469 // ms = 0, will sleep for the least amount of time allowed by the OS.
470 static void naked_short_sleep(jlong ms);
471 static void infinite_sleep(); // never returns, use with CAUTION
472 static void naked_yield () ;
473 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
474 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
475
476 static void interrupt(Thread* thread);
477 static bool is_interrupted(Thread* thread, bool clear_interrupted);
478
479 static int pd_self_suspend_thread(Thread* thread);
480
481 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
482 static frame fetch_frame_from_context(const void* ucVoid);
483 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
484
485 static ExtendedPC get_thread_pc(Thread *thread);
486 static void breakpoint();
487 static bool start_debugging(char *buf, int buflen);
488
489 static address current_stack_pointer();
490 static address current_stack_base();
491 static size_t current_stack_size();
492
493 static void verify_stack_alignment() PRODUCT_RETURN;
494
495 static bool message_box(const char* title, const char* message);
496 static char* do_you_want_to_debug(const char* message);
497
498 // run cmd in a separate process and return its exit code; or -1 on failures
499 static int fork_and_exec(char *cmd);
500
501 // Call ::exit() on all platforms but Windows
502 static void exit(int num);
503
504 // Terminate the VM, but don't exit the process
505 static void shutdown();
506
507 // Terminate with an error. Default is to generate a core file on platforms
508 // that support such things. This calls shutdown() and then aborts.
509 static void abort(bool dump_core, void *siginfo, const void *context);
510 static void abort(bool dump_core = true);
511
512 // Die immediately, no exit hook, no abort hook, no cleanup.
513 static void die();
514
515 // File i/o operations
516 static const int default_file_open_flags();
517 static int open(const char *path, int oflag, int mode);
518 static FILE* open(int fd, const char* mode);
519 static int close(int fd);
520 static jlong lseek(int fd, jlong offset, int whence);
521 static char* native_path(char *path);
522 static int ftruncate(int fd, jlong length);
523 static int fsync(int fd);
524 static int available(int fd, jlong *bytes);
525 static int get_fileno(FILE* fp);
526 static void flockfile(FILE* fp);
527 static void funlockfile(FILE* fp);
528
529 static int compare_file_modified_times(const char* file1, const char* file2);
530
531 //File i/o operations
532
533 static size_t read(int fd, void *buf, unsigned int nBytes);
534 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
535 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
536 static size_t write(int fd, const void *buf, unsigned int nBytes);
537
538 // Reading directories.
539 static DIR* opendir(const char* dirname);
540 static int readdir_buf_size(const char *path);
541 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
542 static int closedir(DIR* dirp);
543
544 // Dynamic library extension
545 static const char* dll_file_extension();
546
547 static const char* get_temp_directory();
548 static const char* get_current_directory(char *buf, size_t buflen);
549
550 // Builds a platform-specific full library path given a ld path and lib name
551 // Returns true if buffer contains full path to existing file, false otherwise
552 static bool dll_build_name(char* buffer, size_t size,
553 const char* pathname, const char* fname);
554
555 // Symbol lookup, find nearest function name; basically it implements
556 // dladdr() for all platforms. Name of the nearest function is copied
557 // to buf. Distance from its base address is optionally returned as offset.
558 // If function name is not found, buf[0] is set to '\0' and offset is
559 // set to -1 (if offset is non-NULL).
560 static bool dll_address_to_function_name(address addr, char* buf,
561 int buflen, int* offset,
562 bool demangle = true);
563
564 // Locate DLL/DSO. On success, full path of the library is copied to
565 // buf, and offset is optionally set to be the distance between addr
566 // and the library's base address. On failure, buf[0] is set to '\0'
567 // and offset is set to -1 (if offset is non-NULL).
568 static bool dll_address_to_library_name(address addr, char* buf,
569 int buflen, int* offset);
570
571 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
572 static bool address_is_in_vm(address addr);
573
574 // Loads .dll/.so and
575 // in case of error it checks if .dll/.so was built for the
576 // same architecture as HotSpot is running on
577 static void* dll_load(const char *name, char *ebuf, int ebuflen);
578
579 // lookup symbol in a shared library
580 static void* dll_lookup(void* handle, const char* name);
581
582 // Unload library
583 static void dll_unload(void *lib);
584
585 // Callback for loaded module information
586 // Input parameters:
587 // char* module_file_name,
588 // address module_base_addr,
589 // address module_top_addr,
590 // void* param
591 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
592
593 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
594
595 // Return the handle of this process
596 static void* get_default_process_handle();
597
598 // Check for static linked agent library
599 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
600 size_t syms_len);
601
602 // Find agent entry point
603 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
604 const char *syms[], size_t syms_len);
605
606 // Write to stream
607 static int log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
608
609 // Get host name in buffer provided
610 static bool get_host_name(char* buf, size_t buflen);
611
612 // Print out system information; they are called by fatal error handler.
613 // Output format may be different on different platforms.
614 static void print_os_info(outputStream* st);
615 static void print_os_info_brief(outputStream* st);
616 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
617 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
618 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
619 static void print_memory_info(outputStream* st);
620 static void print_dll_info(outputStream* st);
621 static void print_environment_variables(outputStream* st, const char** env_list);
622 static void print_context(outputStream* st, const void* context);
623 static void print_register_info(outputStream* st, const void* context);
624 static void print_siginfo(outputStream* st, const void* siginfo);
625 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
626 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
627
628 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
629 static size_t lasterror(char *buf, size_t len);
630 static int get_last_error();
631
632 // Replacement for strerror().
633 // Will return the english description of the error (e.g. "File not found", as
634 // suggested in the POSIX standard.
635 // Will return "Unknown error" for an unknown errno value.
636 // Will not attempt to localize the returned string.
637 // Will always return a valid string which is a static constant.
638 // Will not change the value of errno.
639 static const char* strerror(int e);
640
641 // Will return the literalized version of the given errno (e.g. "EINVAL"
642 // for EINVAL).
643 // Will return "Unknown error" for an unknown errno value.
644 // Will always return a valid string which is a static constant.
645 // Will not change the value of errno.
646 static const char* errno_name(int e);
647
648 // Determines whether the calling process is being debugged by a user-mode debugger.
649 static bool is_debugger_attached();
650
651 // wait for a key press if PauseAtExit is set
652 static void wait_for_keypress_at_exit(void);
653
654 // The following two functions are used by fatal error handler to trace
655 // native (C) frames. They are not part of frame.hpp/frame.cpp because
656 // frame.hpp/cpp assume thread is JavaThread, and also because different
657 // OS/compiler may have different convention or provide different API to
658 // walk C frames.
659 //
660 // We don't attempt to become a debugger, so we only follow frames if that
661 // does not require a lookup in the unwind table, which is part of the binary
662 // file but may be unsafe to read after a fatal error. So on x86, we can
663 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
664 // possible to walk C stack without having the unwind table.
665 static bool is_first_C_frame(frame *fr);
666 static frame get_sender_for_C_frame(frame *fr);
667
668 // return current frame. pc() and sp() are set to NULL on failure.
669 static frame current_frame();
670
671 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
672
673 // returns a string to describe the exception/signal;
674 // returns NULL if exception_code is not an OS exception/signal.
675 static const char* exception_name(int exception_code, char* buf, size_t buflen);
676
677 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
678 static int get_signal_number(const char* signal_name);
679
680 // Returns native Java library, loads if necessary
681 static void* native_java_library();
682
683 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
684 static void jvm_path(char *buf, jint buflen);
685
686 // Returns true if we are running in a headless jre.
687 static bool is_headless_jre();
688
689 // JNI names
690 static void print_jni_name_prefix_on(outputStream* st, int args_size);
691 static void print_jni_name_suffix_on(outputStream* st, int args_size);
692
693 // Init os specific system properties values
694 static void init_system_properties_values();
695
696 // IO operations, non-JVM_ version.
697 static int stat(const char* path, struct stat* sbuf);
698 static bool dir_is_empty(const char* path);
699
700 // IO operations on binary files
701 static int create_binary_file(const char* path, bool rewrite_existing);
702 static jlong current_file_offset(int fd);
703 static jlong seek_to_file_offset(int fd, jlong offset);
704
705 // Retrieve native stack frames.
706 // Parameter:
707 // stack: an array to storage stack pointers.
708 // frames: size of above array.
709 // toSkip: number of stack frames to skip at the beginning.
710 // Return: number of stack frames captured.
711 static int get_native_stack(address* stack, int size, int toSkip = 0);
712
713 // General allocation (must be MT-safe)
714 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
715 static void* malloc (size_t size, MEMFLAGS flags);
716 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
717 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
718
719 static void free (void *memblock);
720 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
721 // Like strdup, but exit VM when strdup() returns NULL
722 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
723
724 #ifndef PRODUCT
725 static julong num_mallocs; // # of calls to malloc/realloc
726 static julong alloc_bytes; // # of bytes allocated
727 static julong num_frees; // # of calls to free
728 static julong free_bytes; // # of bytes freed
729 #endif
730
731 // SocketInterface (ex HPI SocketInterface )
732 static int socket(int domain, int type, int protocol);
733 static int socket_close(int fd);
734 static int recv(int fd, char* buf, size_t nBytes, uint flags);
735 static int send(int fd, char* buf, size_t nBytes, uint flags);
736 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
737 static int connect(int fd, struct sockaddr* him, socklen_t len);
738 static struct hostent* get_host_by_name(char* name);
739
740 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
741 static void signal_init();
742 static void signal_init_pd();
743 static void signal_notify(int signal_number);
744 static void* signal(int signal_number, void* handler);
745 static void signal_raise(int signal_number);
746 static int signal_wait();
747 static int signal_lookup();
748 static void* user_handler();
749 static void terminate_signal_thread();
750 static int sigexitnum_pd();
751
752 // random number generation
753 static long random(); // return 32bit pseudorandom number
754 static void init_random(long initval); // initialize random sequence
755
756 // Structured OS Exception support
757 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
758
759 // On Posix compatible OS it will simply check core dump limits while on Windows
760 // it will check if dump file can be created. Check or prepare a core dump to be
761 // taken at a later point in the same thread in os::abort(). Use the caller
762 // provided buffer as a scratch buffer. The status message which will be written
763 // into the error log either is file location or a short error message, depending
764 // on the checking result.
765 static void check_dump_limit(char* buffer, size_t bufferSize);
766
767 // Get the default path to the core file
768 // Returns the length of the string
769 static int get_core_path(char* buffer, size_t bufferSize);
770
771 // JVMTI & JVM monitoring and management support
772 // The thread_cpu_time() and current_thread_cpu_time() are only
773 // supported if is_thread_cpu_time_supported() returns true.
774 // They are not supported on Solaris T1.
775
776 // Thread CPU Time - return the fast estimate on a platform
777 // On Solaris - call gethrvtime (fast) - user time only
778 // On Linux - fast clock_gettime where available - user+sys
779 // - otherwise: very slow /proc fs - user+sys
780 // On Windows - GetThreadTimes - user+sys
781 static jlong current_thread_cpu_time();
782 static jlong thread_cpu_time(Thread* t);
783
784 // Thread CPU Time with user_sys_cpu_time parameter.
785 //
786 // If user_sys_cpu_time is true, user+sys time is returned.
787 // Otherwise, only user time is returned
788 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
789 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
790
791 // Return a bunch of info about the timers.
792 // Note that the returned info for these two functions may be different
793 // on some platforms
794 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
795 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
796
797 static bool is_thread_cpu_time_supported();
798
799 // System loadavg support. Returns -1 if load average cannot be obtained.
800 static int loadavg(double loadavg[], int nelem);
801
802 // Hook for os specific jvm options that we don't want to abort on seeing
803 static bool obsolete_option(const JavaVMOption *option);
804
805 // Amount beyond the callee frame size that we bang the stack.
806 static int extra_bang_size_in_bytes();
807
808 static char** split_path(const char* path, int* n);
809
810 // Extensions
811 #include "runtime/os_ext.hpp"
812
813 public:
814 class CrashProtectionCallback : public StackObj {
815 public:
816 virtual void call() = 0;
817 };
818
819 // Platform dependent stuff
820 #ifndef _WINDOWS
821 # include "os_posix.hpp"
822 #endif
823 #include OS_CPU_HEADER(os)
824 #include OS_HEADER(os)
825
826 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
827 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
828 #endif
829
830 public:
831 #ifndef PLATFORM_PRINT_NATIVE_STACK
832 // No platform-specific code for printing the native stack.
833 static bool platform_print_native_stack(outputStream* st, const void* context,
834 char *buf, int buf_size) {
835 return false;
836 }
837 #endif
838
839 // debugging support (mostly used by debug.cpp but also fatal error handler)
840 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
841
842 static bool dont_yield(); // when true, JVM_Yield() is nop
843 static void print_statistics();
844
845 // Thread priority helpers (implemented in OS-specific part)
846 static OSReturn set_native_priority(Thread* thread, int native_prio);
847 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
848 static int java_to_os_priority[CriticalPriority + 1];
849 // Hint to the underlying OS that a task switch would not be good.
850 // Void return because it's a hint and can fail.
851 static void hint_no_preempt();
852 static const char* native_thread_creation_failed_msg() {
853 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
854 }
855
856 // Used at creation if requested by the diagnostic flag PauseAtStartup.
857 // Causes the VM to wait until an external stimulus has been applied
858 // (for Unix, that stimulus is a signal, for Windows, an external
859 // ResumeThread call)
860 static void pause();
861
862 // Builds a platform dependent Agent_OnLoad_<libname> function name
863 // which is used to find statically linked in agents.
864 static char* build_agent_function_name(const char *sym, const char *cname,
865 bool is_absolute_path);
866
867 class SuspendedThreadTaskContext {
868 public:
869 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
870 Thread* thread() const { return _thread; }
871 void* ucontext() const { return _ucontext; }
872 private:
873 Thread* _thread;
874 void* _ucontext;
875 };
876
877 class SuspendedThreadTask {
878 public:
879 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
880 virtual ~SuspendedThreadTask() {}
881 void run();
882 bool is_done() { return _done; }
883 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
884 protected:
885 private:
886 void internal_do_task();
887 Thread* _thread;
888 bool _done;
889 };
890
891 #ifndef _WINDOWS
892 // Suspend/resume support
893 // Protocol:
894 //
895 // a thread starts in SR_RUNNING
896 //
897 // SR_RUNNING can go to
898 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
899 // SR_SUSPEND_REQUEST can go to
900 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
901 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
902 // SR_SUSPENDED can go to
903 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
904 // SR_WAKEUP_REQUEST can go to
905 // * SR_RUNNING when the stopped thread receives the signal
906 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
907 class SuspendResume {
908 public:
909 enum State {
910 SR_RUNNING,
911 SR_SUSPEND_REQUEST,
912 SR_SUSPENDED,
913 SR_WAKEUP_REQUEST
914 };
915
916 private:
917 volatile State _state;
918
919 private:
920 /* try to switch state from state "from" to state "to"
921 * returns the state set after the method is complete
922 */
923 State switch_state(State from, State to);
924
925 public:
926 SuspendResume() : _state(SR_RUNNING) { }
927
928 State state() const { return _state; }
929
930 State request_suspend() {
931 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
932 }
933
934 State cancel_suspend() {
935 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
936 }
937
938 State suspended() {
939 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
940 }
941
942 State request_wakeup() {
943 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
944 }
945
946 State running() {
947 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
948 }
949
950 bool is_running() const {
951 return _state == SR_RUNNING;
952 }
953
954 bool is_suspend_request() const {
955 return _state == SR_SUSPEND_REQUEST;
956 }
957
958 bool is_suspended() const {
959 return _state == SR_SUSPENDED;
960 }
961 };
962 #endif // !WINDOWS
963
964
965 protected:
966 static long _rand_seed; // seed for random number generator
967 static int _processor_count; // number of processors
968 static int _initial_active_processor_count; // number of active processors during initialization.
969
970 static char* format_boot_path(const char* format_string,
971 const char* home,
972 int home_len,
973 char fileSep,
974 char pathSep);
975 static bool set_boot_path(char fileSep, char pathSep);
976
977 };
978
979 // Note that "PAUSE" is almost always used with synchronization
980 // so arguably we should provide Atomic::SpinPause() instead
981 // of the global SpinPause() with C linkage.
982 // It'd also be eligible for inlining on many platforms.
983
984 extern "C" int SpinPause();
985
986 #endif // SHARE_VM_RUNTIME_OS_HPP