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 #if defined(AIX)
112 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr, bool use_SHM = true);
113 #else
114 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
115 #endif
116 static void pd_split_reserved_memory(char *base, size_t size,
117 size_t split, bool realloc);
118 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
119 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
120 bool executable);
121 // Same as pd_commit_memory() that either succeeds or calls
122 // vm_exit_out_of_memory() with the specified mesg.
123 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
124 bool executable, const char* mesg);
125 static void pd_commit_memory_or_exit(char* addr, size_t size,
126 size_t alignment_hint,
127 bool executable, const char* mesg);
128 static bool pd_uncommit_memory(char* addr, size_t bytes);
129 static bool pd_release_memory(char* addr, size_t bytes);
130
131 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
132 char *addr, size_t bytes, bool read_only = false,
133 bool allow_exec = false);
134 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
135 char *addr, size_t bytes, bool read_only,
136 bool allow_exec);
137 static bool pd_unmap_memory(char *addr, size_t bytes);
138 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
139 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
140
141 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
142
143 // Get summary strings for system information in buffer provided
144 static void get_summary_cpu_info(char* buf, size_t buflen);
145 static void get_summary_os_info(char* buf, size_t buflen);
146
147 static void initialize_initial_active_processor_count();
148 public:
149 static void init(void); // Called before command line parsing
150 static void init_before_ergo(void); // Called after command line parsing
151 // before VM ergonomics processing.
152 static jint init_2(void); // Called after command line parsing
153 // and VM ergonomics processing
154 static void init_globals(void) { // Called from init_globals() in init.cpp
155 init_globals_ext();
156 }
157
158 // File names are case-insensitive on windows only
159 // Override me as needed
160 static int file_name_strcmp(const char* s1, const char* s2);
161
162 // unset environment variable
163 static bool unsetenv(const char* name);
164
165 static bool have_special_privileges();
166
167 static jlong javaTimeMillis();
168 static jlong javaTimeNanos();
169 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
170 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
171 static void run_periodic_checks();
172 static bool supports_monotonic_clock();
173
174 // Returns the elapsed time in seconds since the vm started.
175 static double elapsedTime();
176
177 // Returns real time in seconds since an arbitrary point
178 // in the past.
179 static bool getTimesSecs(double* process_real_time,
180 double* process_user_time,
181 double* process_system_time);
182
183 // Interface to the performance counter
184 static jlong elapsed_counter();
185 static jlong elapsed_frequency();
186
187 // The "virtual time" of a thread is the amount of time a thread has
188 // actually run. The first function indicates whether the OS supports
189 // this functionality for the current thread, and if so:
190 // * the second enables vtime tracking (if that is required).
191 // * the third tells whether vtime is enabled.
192 // * the fourth returns the elapsed virtual time for the current
193 // thread.
194 static bool supports_vtime();
195 static bool enable_vtime();
196 static bool vtime_enabled();
197 static double elapsedVTime();
198
199 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
200 // It is MT safe, but not async-safe, as reading time zone
201 // information may require a lock on some platforms.
202 static char* local_time_string(char *buf, size_t buflen);
203 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
204 static struct tm* gmtime_pd (const time_t* clock, struct tm* res);
205 // Fill in buffer with current local time as an ISO-8601 string.
206 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
207 // Returns buffer, or NULL if it failed.
208 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false);
209
210 // Interface for detecting multiprocessor system
211 static inline bool is_MP() {
212 // During bootstrap if _processor_count is not yet initialized
213 // we claim to be MP as that is safest. If any platform has a
214 // stub generator that might be triggered in this phase and for
215 // which being declared MP when in fact not, is a problem - then
216 // the bootstrap routine for the stub generator needs to check
217 // the processor count directly and leave the bootstrap routine
218 // in place until called after initialization has ocurred.
219 return (_processor_count != 1) || AssumeMP;
220 }
221 static julong available_memory();
222 static julong physical_memory();
223 static bool has_allocatable_memory_limit(julong* limit);
224 static bool is_server_class_machine();
225
226 // number of CPUs
227 static int processor_count() {
228 return _processor_count;
229 }
230 static void set_processor_count(int count) { _processor_count = count; }
231
232 // Returns the number of CPUs this process is currently allowed to run on.
233 // Note that on some OSes this can change dynamically.
234 static int active_processor_count();
235
236 // At startup the number of active CPUs this process is allowed to run on.
237 // This value does not change dynamically. May be different from active_processor_count().
238 static int initial_active_processor_count() {
239 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
240 return _initial_active_processor_count;
241 }
242
243 // Bind processes to processors.
244 // This is a two step procedure:
245 // first you generate a distribution of processes to processors,
246 // then you bind processes according to that distribution.
247 // Compute a distribution for number of processes to processors.
248 // Stores the processor id's into the distribution array argument.
249 // Returns true if it worked, false if it didn't.
250 static bool distribute_processes(uint length, uint* distribution);
251 // Binds the current process to a processor.
252 // Returns true if it worked, false if it didn't.
253 static bool bind_to_processor(uint processor_id);
254
255 // Give a name to the current thread.
256 static void set_native_thread_name(const char *name);
257
258 // Interface for stack banging (predetect possible stack overflow for
259 // exception processing) There are guard pages, and above that shadow
260 // pages for stack overflow checking.
261 static bool uses_stack_guard_pages();
262 static bool must_commit_stack_guard_pages();
263 static void map_stack_shadow_pages(address sp);
264 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
265
266 // OS interface to Virtual Memory
267
268 // Return the default page size.
269 static int vm_page_size();
270
271 // Returns the page size to use for a region of memory.
272 // region_size / min_pages will always be greater than or equal to the
273 // returned value. The returned value will divide region_size.
274 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
275
276 // Returns the page size to use for a region of memory.
277 // region_size / min_pages will always be greater than or equal to the
278 // returned value. The returned value might not divide region_size.
279 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
280
281 // Return the largest page size that can be used
282 static size_t max_page_size() {
283 // The _page_sizes array is sorted in descending order.
284 return _page_sizes[0];
285 }
286
287 // Methods for tracing page sizes returned by the above method.
288 // The region_{min,max}_size parameters should be the values
289 // passed to page_size_for_region() and page_size should be the result of that
290 // call. The (optional) base and size parameters should come from the
291 // ReservedSpace base() and size() methods.
292 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
293 static void trace_page_sizes(const char* str,
294 const size_t region_min_size,
295 const size_t region_max_size,
296 const size_t page_size,
297 const char* base,
298 const size_t size);
299 static void trace_page_sizes_for_requested_size(const char* str,
300 const size_t requested_size,
301 const size_t page_size,
302 const size_t alignment,
303 const char* base,
304 const size_t size);
305
306 static int vm_allocation_granularity();
307 static char* reserve_memory(size_t bytes, char* addr = 0,
308 size_t alignment_hint = 0, int file_desc = -1);
309 static char* reserve_memory(size_t bytes, char* addr,
310 size_t alignment_hint, MEMFLAGS flags);
311 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1);
312 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1);
313
314 static void split_reserved_memory(char *base, size_t size,
315 size_t split, bool realloc);
316 static bool commit_memory(char* addr, size_t bytes, bool executable);
317 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
318 bool executable);
319 // Same as commit_memory() that either succeeds or calls
320 // vm_exit_out_of_memory() with the specified mesg.
321 static void commit_memory_or_exit(char* addr, size_t bytes,
322 bool executable, const char* mesg);
323 static void commit_memory_or_exit(char* addr, size_t size,
324 size_t alignment_hint,
325 bool executable, const char* mesg);
326 static bool uncommit_memory(char* addr, size_t bytes);
327 static bool release_memory(char* addr, size_t bytes);
328
329 // Touch memory pages that cover the memory range from start to end (exclusive)
330 // to make the OS back the memory range with actual memory.
331 // Current implementation may not touch the last page if unaligned addresses
332 // are passed.
333 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
334
335 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
336 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
337 bool is_committed = true);
338
339 static bool guard_memory(char* addr, size_t bytes);
340 static bool unguard_memory(char* addr, size_t bytes);
341 static bool create_stack_guard_pages(char* addr, size_t bytes);
342 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
343 static bool remove_stack_guard_pages(char* addr, size_t bytes);
344
345 // Helper function to create a new file with template jvmheap.XXXXXX
346 static int create_file_for_heap(const char* dir, size_t size);
347 // map memory to the dax (direct access) file referred by fd
348 static char* map_memory_to_dax_file(char* base, size_t size, int fd);
349 // replace existing reserved memory with file mapping
350 static char* replace_existing_mapping_with_dax_file_mapping(char* base, size_t size, int fd);
351
352 static char* map_memory(int fd, const char* file_name, size_t file_offset,
353 char *addr, size_t bytes, bool read_only = false,
354 bool allow_exec = false);
355 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
356 char *addr, size_t bytes, bool read_only,
357 bool allow_exec);
358 static bool unmap_memory(char *addr, size_t bytes);
359 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
360 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
361
362 // NUMA-specific interface
363 static bool numa_has_static_binding();
364 static bool numa_has_group_homing();
365 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
366 static void numa_make_global(char *addr, size_t bytes);
367 static size_t numa_get_groups_num();
368 static size_t numa_get_leaf_groups(int *ids, size_t size);
369 static bool numa_topology_changed();
370 static int numa_get_group_id();
371
372 // Page manipulation
373 struct page_info {
374 size_t size;
375 int lgrp_id;
376 };
377 static bool get_page_info(char *start, page_info* info);
378 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
379
380 static char* non_memory_address_word();
381 // reserve, commit and pin the entire memory region
382 static char* reserve_memory_special(size_t size, size_t alignment,
383 char* addr, bool executable);
384 static bool release_memory_special(char* addr, size_t bytes);
385 static void large_page_init();
386 static size_t large_page_size();
387 static bool can_commit_large_page_memory();
388 static bool can_execute_large_page_memory();
389
390 // OS interface to polling page
391 static address get_polling_page() { return _polling_page; }
392 static void set_polling_page(address page) { _polling_page = page; }
393 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
394 static void make_polling_page_unreadable();
395 static void make_polling_page_readable();
396
397 // Routines used to serialize the thread state without using membars
398 static void serialize_thread_states();
399
400 // Since we write to the serialize page from every thread, we
401 // want stores to be on unique cache lines whenever possible
402 // in order to minimize CPU cross talk. We pre-compute the
403 // amount to shift the thread* to make this offset unique to
404 // each thread.
405 static int get_serialize_page_shift_count() {
406 return SerializePageShiftCount;
407 }
408
409 static void set_serialize_page_mask(uintptr_t mask) {
410 _serialize_page_mask = mask;
411 }
412
413 static unsigned int get_serialize_page_mask() {
414 return _serialize_page_mask;
415 }
416
417 static void set_memory_serialize_page(address page);
418
419 static address get_memory_serialize_page() {
420 return (address)_mem_serialize_page;
421 }
422
423 static inline void write_memory_serialize_page(JavaThread *thread) {
424 uintptr_t page_offset = ((uintptr_t)thread >>
425 get_serialize_page_shift_count()) &
426 get_serialize_page_mask();
427 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
428 }
429
430 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
431 if (UseMembar) return false;
432 // Previously this function calculated the exact address of this
433 // thread's serialize page, and checked if the faulting address
434 // was equal. However, some platforms mask off faulting addresses
435 // to the page size, so now we just check that the address is
436 // within the page. This makes the thread argument unnecessary,
437 // but we retain the NULL check to preserve existing behavior.
438 if (thread == NULL) return false;
439 address page = (address) _mem_serialize_page;
440 return addr >= page && addr < (page + os::vm_page_size());
441 }
442
443 static void block_on_serialize_page_trap();
444
445 // threads
446
447 enum ThreadType {
448 vm_thread,
449 cgc_thread, // Concurrent GC thread
450 pgc_thread, // Parallel GC thread
451 java_thread,
452 compiler_thread,
453 watcher_thread,
454 os_thread
455 };
456
457 static bool create_thread(Thread* thread,
458 ThreadType thr_type,
459 size_t req_stack_size = 0);
460 static bool create_main_thread(JavaThread* thread);
461 static bool create_attached_thread(JavaThread* thread);
462 static void pd_start_thread(Thread* thread);
463 static void start_thread(Thread* thread);
464
465 static void initialize_thread(Thread* thr);
466 static void free_thread(OSThread* osthread);
467
468 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
469 static intx current_thread_id();
470 static int current_process_id();
471 static int sleep(Thread* thread, jlong ms, bool interruptable);
472 // Short standalone OS sleep suitable for slow path spin loop.
473 // Ignores Thread.interrupt() (so keep it short).
474 // ms = 0, will sleep for the least amount of time allowed by the OS.
475 static void naked_short_sleep(jlong ms);
476 static void infinite_sleep(); // never returns, use with CAUTION
477 static void naked_yield () ;
478 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
479 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
480
481 static void interrupt(Thread* thread);
482 static bool is_interrupted(Thread* thread, bool clear_interrupted);
483
484 static int pd_self_suspend_thread(Thread* thread);
485
486 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
487 static frame fetch_frame_from_context(const void* ucVoid);
488 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
489
490 static ExtendedPC get_thread_pc(Thread *thread);
491 static void breakpoint();
492 static bool start_debugging(char *buf, int buflen);
493
494 static address current_stack_pointer();
495 static address current_stack_base();
496 static size_t current_stack_size();
497
498 static void verify_stack_alignment() PRODUCT_RETURN;
499
500 static bool message_box(const char* title, const char* message);
501 static char* do_you_want_to_debug(const char* message);
502
503 // run cmd in a separate process and return its exit code; or -1 on failures
504 static int fork_and_exec(char *cmd);
505
506 // Call ::exit() on all platforms but Windows
507 static void exit(int num);
508
509 // Terminate the VM, but don't exit the process
510 static void shutdown();
511
512 // Terminate with an error. Default is to generate a core file on platforms
513 // that support such things. This calls shutdown() and then aborts.
514 static void abort(bool dump_core, void *siginfo, const void *context);
515 static void abort(bool dump_core = true);
516
517 // Die immediately, no exit hook, no abort hook, no cleanup.
518 static void die();
519
520 // File i/o operations
521 static const int default_file_open_flags();
522 static int open(const char *path, int oflag, int mode);
523 static FILE* open(int fd, const char* mode);
524 static int close(int fd);
525 static jlong lseek(int fd, jlong offset, int whence);
526 static char* native_path(char *path);
527 static int ftruncate(int fd, jlong length);
528 static int fsync(int fd);
529 static int available(int fd, jlong *bytes);
530 static int get_fileno(FILE* fp);
531 static void flockfile(FILE* fp);
532 static void funlockfile(FILE* fp);
533
534 static int compare_file_modified_times(const char* file1, const char* file2);
535
536 //File i/o operations
537
538 static size_t read(int fd, void *buf, unsigned int nBytes);
539 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
540 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
541 static size_t write(int fd, const void *buf, unsigned int nBytes);
542
543 // Reading directories.
544 static DIR* opendir(const char* dirname);
545 static int readdir_buf_size(const char *path);
546 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
547 static int closedir(DIR* dirp);
548
549 // Dynamic library extension
550 static const char* dll_file_extension();
551
552 static const char* get_temp_directory();
553 static const char* get_current_directory(char *buf, size_t buflen);
554
555 // Builds a platform-specific full library path given a ld path and lib name
556 // Returns true if buffer contains full path to existing file, false otherwise
557 static bool dll_build_name(char* buffer, size_t size,
558 const char* pathname, const char* fname);
559
560 // Symbol lookup, find nearest function name; basically it implements
561 // dladdr() for all platforms. Name of the nearest function is copied
562 // to buf. Distance from its base address is optionally returned as offset.
563 // If function name is not found, buf[0] is set to '\0' and offset is
564 // set to -1 (if offset is non-NULL).
565 static bool dll_address_to_function_name(address addr, char* buf,
566 int buflen, int* offset,
567 bool demangle = true);
568
569 // Locate DLL/DSO. On success, full path of the library is copied to
570 // buf, and offset is optionally set to be the distance between addr
571 // and the library's base address. On failure, buf[0] is set to '\0'
572 // and offset is set to -1 (if offset is non-NULL).
573 static bool dll_address_to_library_name(address addr, char* buf,
574 int buflen, int* offset);
575
576 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
577 static bool address_is_in_vm(address addr);
578
579 // Loads .dll/.so and
580 // in case of error it checks if .dll/.so was built for the
581 // same architecture as HotSpot is running on
582 static void* dll_load(const char *name, char *ebuf, int ebuflen);
583
584 // lookup symbol in a shared library
585 static void* dll_lookup(void* handle, const char* name);
586
587 // Unload library
588 static void dll_unload(void *lib);
589
590 // Callback for loaded module information
591 // Input parameters:
592 // char* module_file_name,
593 // address module_base_addr,
594 // address module_top_addr,
595 // void* param
596 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
597
598 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
599
600 // Return the handle of this process
601 static void* get_default_process_handle();
602
603 // Check for static linked agent library
604 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
605 size_t syms_len);
606
607 // Find agent entry point
608 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
609 const char *syms[], size_t syms_len);
610
611 // Write to stream
612 static int log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
613
614 // Get host name in buffer provided
615 static bool get_host_name(char* buf, size_t buflen);
616
617 // Print out system information; they are called by fatal error handler.
618 // Output format may be different on different platforms.
619 static void print_os_info(outputStream* st);
620 static void print_os_info_brief(outputStream* st);
621 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
622 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
623 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
624 static void print_memory_info(outputStream* st);
625 static void print_dll_info(outputStream* st);
626 static void print_environment_variables(outputStream* st, const char** env_list);
627 static void print_context(outputStream* st, const void* context);
628 static void print_register_info(outputStream* st, const void* context);
629 static void print_siginfo(outputStream* st, const void* siginfo);
630 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
631 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
632
633 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
634 static size_t lasterror(char *buf, size_t len);
635 static int get_last_error();
636
637 // Replacement for strerror().
638 // Will return the english description of the error (e.g. "File not found", as
639 // suggested in the POSIX standard.
640 // Will return "Unknown error" for an unknown errno value.
641 // Will not attempt to localize the returned string.
642 // Will always return a valid string which is a static constant.
643 // Will not change the value of errno.
644 static const char* strerror(int e);
645
646 // Will return the literalized version of the given errno (e.g. "EINVAL"
647 // for EINVAL).
648 // Will return "Unknown error" for an unknown errno value.
649 // Will always return a valid string which is a static constant.
650 // Will not change the value of errno.
651 static const char* errno_name(int e);
652
653 // Determines whether the calling process is being debugged by a user-mode debugger.
654 static bool is_debugger_attached();
655
656 // wait for a key press if PauseAtExit is set
657 static void wait_for_keypress_at_exit(void);
658
659 // The following two functions are used by fatal error handler to trace
660 // native (C) frames. They are not part of frame.hpp/frame.cpp because
661 // frame.hpp/cpp assume thread is JavaThread, and also because different
662 // OS/compiler may have different convention or provide different API to
663 // walk C frames.
664 //
665 // We don't attempt to become a debugger, so we only follow frames if that
666 // does not require a lookup in the unwind table, which is part of the binary
667 // file but may be unsafe to read after a fatal error. So on x86, we can
668 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
669 // possible to walk C stack without having the unwind table.
670 static bool is_first_C_frame(frame *fr);
671 static frame get_sender_for_C_frame(frame *fr);
672
673 // return current frame. pc() and sp() are set to NULL on failure.
674 static frame current_frame();
675
676 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
677
678 // returns a string to describe the exception/signal;
679 // returns NULL if exception_code is not an OS exception/signal.
680 static const char* exception_name(int exception_code, char* buf, size_t buflen);
681
682 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
683 static int get_signal_number(const char* signal_name);
684
685 // Returns native Java library, loads if necessary
686 static void* native_java_library();
687
688 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
689 static void jvm_path(char *buf, jint buflen);
690
691 // Returns true if we are running in a headless jre.
692 static bool is_headless_jre();
693
694 // JNI names
695 static void print_jni_name_prefix_on(outputStream* st, int args_size);
696 static void print_jni_name_suffix_on(outputStream* st, int args_size);
697
698 // Init os specific system properties values
699 static void init_system_properties_values();
700
701 // IO operations, non-JVM_ version.
702 static int stat(const char* path, struct stat* sbuf);
703 static bool dir_is_empty(const char* path);
704
705 // IO operations on binary files
706 static int create_binary_file(const char* path, bool rewrite_existing);
707 static jlong current_file_offset(int fd);
708 static jlong seek_to_file_offset(int fd, jlong offset);
709
710 // Retrieve native stack frames.
711 // Parameter:
712 // stack: an array to storage stack pointers.
713 // frames: size of above array.
714 // toSkip: number of stack frames to skip at the beginning.
715 // Return: number of stack frames captured.
716 static int get_native_stack(address* stack, int size, int toSkip = 0);
717
718 // General allocation (must be MT-safe)
719 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
720 static void* malloc (size_t size, MEMFLAGS flags);
721 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
722 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
723
724 static void free (void *memblock);
725 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
726 // Like strdup, but exit VM when strdup() returns NULL
727 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
728
729 #ifndef PRODUCT
730 static julong num_mallocs; // # of calls to malloc/realloc
731 static julong alloc_bytes; // # of bytes allocated
732 static julong num_frees; // # of calls to free
733 static julong free_bytes; // # of bytes freed
734 #endif
735
736 // SocketInterface (ex HPI SocketInterface )
737 static int socket(int domain, int type, int protocol);
738 static int socket_close(int fd);
739 static int recv(int fd, char* buf, size_t nBytes, uint flags);
740 static int send(int fd, char* buf, size_t nBytes, uint flags);
741 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
742 static int connect(int fd, struct sockaddr* him, socklen_t len);
743 static struct hostent* get_host_by_name(char* name);
744
745 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
746 static void signal_init();
747 static void signal_init_pd();
748 static void signal_notify(int signal_number);
749 static void* signal(int signal_number, void* handler);
750 static void signal_raise(int signal_number);
751 static int signal_wait();
752 static int signal_lookup();
753 static void* user_handler();
754 static void terminate_signal_thread();
755 static int sigexitnum_pd();
756
757 // random number generation
758 static long random(); // return 32bit pseudorandom number
759 static void init_random(long initval); // initialize random sequence
760
761 // Structured OS Exception support
762 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
763
764 // On Posix compatible OS it will simply check core dump limits while on Windows
765 // it will check if dump file can be created. Check or prepare a core dump to be
766 // taken at a later point in the same thread in os::abort(). Use the caller
767 // provided buffer as a scratch buffer. The status message which will be written
768 // into the error log either is file location or a short error message, depending
769 // on the checking result.
770 static void check_dump_limit(char* buffer, size_t bufferSize);
771
772 // Get the default path to the core file
773 // Returns the length of the string
774 static int get_core_path(char* buffer, size_t bufferSize);
775
776 // JVMTI & JVM monitoring and management support
777 // The thread_cpu_time() and current_thread_cpu_time() are only
778 // supported if is_thread_cpu_time_supported() returns true.
779 // They are not supported on Solaris T1.
780
781 // Thread CPU Time - return the fast estimate on a platform
782 // On Solaris - call gethrvtime (fast) - user time only
783 // On Linux - fast clock_gettime where available - user+sys
784 // - otherwise: very slow /proc fs - user+sys
785 // On Windows - GetThreadTimes - user+sys
786 static jlong current_thread_cpu_time();
787 static jlong thread_cpu_time(Thread* t);
788
789 // Thread CPU Time with user_sys_cpu_time parameter.
790 //
791 // If user_sys_cpu_time is true, user+sys time is returned.
792 // Otherwise, only user time is returned
793 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
794 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
795
796 // Return a bunch of info about the timers.
797 // Note that the returned info for these two functions may be different
798 // on some platforms
799 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
800 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
801
802 static bool is_thread_cpu_time_supported();
803
804 // System loadavg support. Returns -1 if load average cannot be obtained.
805 static int loadavg(double loadavg[], int nelem);
806
807 // Hook for os specific jvm options that we don't want to abort on seeing
808 static bool obsolete_option(const JavaVMOption *option);
809
810 // Amount beyond the callee frame size that we bang the stack.
811 static int extra_bang_size_in_bytes();
812
813 static char** split_path(const char* path, int* n);
814
815 // Extensions
816 #include "runtime/os_ext.hpp"
817
818 public:
819 class CrashProtectionCallback : public StackObj {
820 public:
821 virtual void call() = 0;
822 };
823
824 // Platform dependent stuff
825 #ifndef _WINDOWS
826 # include "os_posix.hpp"
827 #endif
828 #include OS_CPU_HEADER(os)
829 #include OS_HEADER(os)
830
831 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
832 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
833 #endif
834
835 public:
836 #ifndef PLATFORM_PRINT_NATIVE_STACK
837 // No platform-specific code for printing the native stack.
838 static bool platform_print_native_stack(outputStream* st, const void* context,
839 char *buf, int buf_size) {
840 return false;
841 }
842 #endif
843
844 // debugging support (mostly used by debug.cpp but also fatal error handler)
845 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
846
847 static bool dont_yield(); // when true, JVM_Yield() is nop
848 static void print_statistics();
849
850 // Thread priority helpers (implemented in OS-specific part)
851 static OSReturn set_native_priority(Thread* thread, int native_prio);
852 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
853 static int java_to_os_priority[CriticalPriority + 1];
854 // Hint to the underlying OS that a task switch would not be good.
855 // Void return because it's a hint and can fail.
856 static void hint_no_preempt();
857 static const char* native_thread_creation_failed_msg() {
858 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
859 }
860
861 // Used at creation if requested by the diagnostic flag PauseAtStartup.
862 // Causes the VM to wait until an external stimulus has been applied
863 // (for Unix, that stimulus is a signal, for Windows, an external
864 // ResumeThread call)
865 static void pause();
866
867 // Builds a platform dependent Agent_OnLoad_<libname> function name
868 // which is used to find statically linked in agents.
869 static char* build_agent_function_name(const char *sym, const char *cname,
870 bool is_absolute_path);
871
872 class SuspendedThreadTaskContext {
873 public:
874 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
875 Thread* thread() const { return _thread; }
876 void* ucontext() const { return _ucontext; }
877 private:
878 Thread* _thread;
879 void* _ucontext;
880 };
881
882 class SuspendedThreadTask {
883 public:
884 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
885 virtual ~SuspendedThreadTask() {}
886 void run();
887 bool is_done() { return _done; }
888 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
889 protected:
890 private:
891 void internal_do_task();
892 Thread* _thread;
893 bool _done;
894 };
895
896 #ifndef _WINDOWS
897 // Suspend/resume support
898 // Protocol:
899 //
900 // a thread starts in SR_RUNNING
901 //
902 // SR_RUNNING can go to
903 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
904 // SR_SUSPEND_REQUEST can go to
905 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
906 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
907 // SR_SUSPENDED can go to
908 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
909 // SR_WAKEUP_REQUEST can go to
910 // * SR_RUNNING when the stopped thread receives the signal
911 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
912 class SuspendResume {
913 public:
914 enum State {
915 SR_RUNNING,
916 SR_SUSPEND_REQUEST,
917 SR_SUSPENDED,
918 SR_WAKEUP_REQUEST
919 };
920
921 private:
922 volatile State _state;
923
924 private:
925 /* try to switch state from state "from" to state "to"
926 * returns the state set after the method is complete
927 */
928 State switch_state(State from, State to);
929
930 public:
931 SuspendResume() : _state(SR_RUNNING) { }
932
933 State state() const { return _state; }
934
935 State request_suspend() {
936 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
937 }
938
939 State cancel_suspend() {
940 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
941 }
942
943 State suspended() {
944 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
945 }
946
947 State request_wakeup() {
948 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
949 }
950
951 State running() {
952 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
953 }
954
955 bool is_running() const {
956 return _state == SR_RUNNING;
957 }
958
959 bool is_suspend_request() const {
960 return _state == SR_SUSPEND_REQUEST;
961 }
962
963 bool is_suspended() const {
964 return _state == SR_SUSPENDED;
965 }
966 };
967 #endif // !WINDOWS
968
969
970 protected:
971 static long _rand_seed; // seed for random number generator
972 static int _processor_count; // number of processors
973 static int _initial_active_processor_count; // number of active processors during initialization.
974
975 static char* format_boot_path(const char* format_string,
976 const char* home,
977 int home_len,
978 char fileSep,
979 char pathSep);
980 static bool set_boot_path(char fileSep, char pathSep);
981
982 };
983
984 // Note that "PAUSE" is almost always used with synchronization
985 // so arguably we should provide Atomic::SpinPause() instead
986 // of the global SpinPause() with C linkage.
987 // It'd also be eligible for inlining on many platforms.
988
989 extern "C" int SpinPause();
990
991 #endif // SHARE_VM_RUNTIME_OS_HPP