1 /*
2 * Copyright (c) 1997, 2017, 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 class frame;
42
43 // os defines the interface to operating system; this includes traditional
44 // OS services (time, I/O) as well as other functionality with system-
45 // dependent code.
46
47 typedef void (*dll_func)(...);
48
49 class Thread;
50 class JavaThread;
51 class Event;
52 class DLL;
53 class FileHandle;
54 class NativeCallStack;
55
56 template<class E> class GrowableArray;
57
58 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
59
60 // Platform-independent error return values from OS functions
61 enum OSReturn {
62 OS_OK = 0, // Operation was successful
63 OS_ERR = -1, // Operation failed
64 OS_INTRPT = -2, // Operation was interrupted
65 OS_TIMEOUT = -3, // Operation timed out
66 OS_NOMEM = -5, // Operation failed for lack of memory
67 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
68 };
69
70 enum ThreadPriority { // JLS 20.20.1-3
71 NoPriority = -1, // Initial non-priority value
72 MinPriority = 1, // Minimum priority
73 NormPriority = 5, // Normal (non-daemon) priority
74 NearMaxPriority = 9, // High priority, used for VMThread
75 MaxPriority = 10, // Highest priority, used for WatcherThread
76 // ensures that VMThread doesn't starve profiler
77 CriticalPriority = 11 // Critical thread priority
78 };
79
80 // Executable parameter flag for os::commit_memory() and
81 // os::commit_memory_or_exit().
82 const bool ExecMem = true;
83
84 // Typedef for structured exception handling support
85 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
86
87 class MallocTracker;
88
89 class os: AllStatic {
90 friend class VMStructs;
91 friend class JVMCIVMStructs;
92 friend class MallocTracker;
93 public:
94 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
95
96 private:
97 static OSThread* _starting_thread;
98 static address _polling_page;
99 static volatile int32_t * _mem_serialize_page;
100 static uintptr_t _serialize_page_mask;
101 public:
102 static size_t _page_sizes[page_sizes_max];
103
104 private:
105 static void init_page_sizes(size_t default_page_size) {
106 _page_sizes[0] = default_page_size;
107 _page_sizes[1] = 0; // sentinel
108 }
109
110 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
111 size_t alignment_hint = 0);
112 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
113 static void pd_split_reserved_memory(char *base, size_t size,
114 size_t split, bool realloc);
115 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
116 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
117 bool executable);
118 // Same as pd_commit_memory() that either succeeds or calls
119 // vm_exit_out_of_memory() with the specified mesg.
120 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
121 bool executable, const char* mesg);
122 static void pd_commit_memory_or_exit(char* addr, size_t size,
123 size_t alignment_hint,
124 bool executable, const char* mesg);
125 static bool pd_uncommit_memory(char* addr, size_t bytes);
126 static bool pd_release_memory(char* addr, size_t bytes);
127
128 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
129 char *addr, size_t bytes, bool read_only = false,
130 bool allow_exec = false);
131 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
132 char *addr, size_t bytes, bool read_only,
133 bool allow_exec);
134 static bool pd_unmap_memory(char *addr, size_t bytes);
135 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
136 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
137
138 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
139
140 // Get summary strings for system information in buffer provided
141 static void get_summary_cpu_info(char* buf, size_t buflen);
142 static void get_summary_os_info(char* buf, size_t buflen);
143
144 static void initialize_initial_active_processor_count();
145
146 #ifdef LINUX
147 // Container support is currently limited to Linux
148 static void pd_initialize_container_support();
149 #endif
150
151 public:
152 static void init(void); // Called before command line parsing
153 static void init_before_ergo(void); // Called after command line parsing
154 // before VM ergonomics processing.
155 static jint init_2(void); // Called after command line parsing
156 // and VM ergonomics processing
157 static void init_globals(void) { // Called from init_globals() in init.cpp
158 init_globals_ext();
159 }
160
161 #ifdef LINUX
162 // Container support is currently limited to Linux
163 static void initialize_container_support() {
164 pd_initialize_container_support();
165 }
166 #else
167 static void initialize_container_support() {}
168 #endif
169
170
171 // File names are case-insensitive on windows only
172 // Override me as needed
173 static int file_name_strcmp(const char* s1, const char* s2);
174
175 // unset environment variable
176 static bool unsetenv(const char* name);
177
178 static bool have_special_privileges();
179
180 static jlong javaTimeMillis();
181 static jlong javaTimeNanos();
182 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
183 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
184 static void run_periodic_checks();
185 static bool supports_monotonic_clock();
186
187 // Returns the elapsed time in seconds since the vm started.
188 static double elapsedTime();
189
190 // Returns real time in seconds since an arbitrary point
191 // in the past.
192 static bool getTimesSecs(double* process_real_time,
193 double* process_user_time,
194 double* process_system_time);
195
196 // Interface to the performance counter
197 static jlong elapsed_counter();
198 static jlong elapsed_frequency();
199
200 // The "virtual time" of a thread is the amount of time a thread has
201 // actually run. The first function indicates whether the OS supports
202 // this functionality for the current thread, and if so:
203 // * the second enables vtime tracking (if that is required).
204 // * the third tells whether vtime is enabled.
205 // * the fourth returns the elapsed virtual time for the current
206 // thread.
207 static bool supports_vtime();
208 static bool enable_vtime();
209 static bool vtime_enabled();
210 static double elapsedVTime();
211
212 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
213 // It is MT safe, but not async-safe, as reading time zone
214 // information may require a lock on some platforms.
215 static char* local_time_string(char *buf, size_t buflen);
216 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
217 static struct tm* gmtime_pd (const time_t* clock, struct tm* res);
218 // Fill in buffer with current local time as an ISO-8601 string.
219 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
220 // Returns buffer, or NULL if it failed.
221 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false);
222
223 // Interface for detecting multiprocessor system
224 static inline bool is_MP() {
225 // During bootstrap if _processor_count is not yet initialized
226 // we claim to be MP as that is safest. If any platform has a
227 // stub generator that might be triggered in this phase and for
228 // which being declared MP when in fact not, is a problem - then
229 // the bootstrap routine for the stub generator needs to check
230 // the processor count directly and leave the bootstrap routine
231 // in place until called after initialization has ocurred.
232 return (_processor_count != 1) || AssumeMP;
233 }
234 static julong available_memory();
235 static julong physical_memory();
236 static bool has_allocatable_memory_limit(julong* limit);
237 static bool is_server_class_machine();
238
239 // number of CPUs
240 static int processor_count() {
241 return _processor_count;
242 }
243 static void set_processor_count(int count) { _processor_count = count; }
244
245 // Returns the number of CPUs this process is currently allowed to run on.
246 // Note that on some OSes this can change dynamically.
247 static int active_processor_count();
248
249 // At startup the number of active CPUs this process is allowed to run on.
250 // This value does not change dynamically. May be different from active_processor_count().
251 static int initial_active_processor_count() {
252 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
253 return _initial_active_processor_count;
254 }
255
256 // Bind processes to processors.
257 // This is a two step procedure:
258 // first you generate a distribution of processes to processors,
259 // then you bind processes according to that distribution.
260 // Compute a distribution for number of processes to processors.
261 // Stores the processor id's into the distribution array argument.
262 // Returns true if it worked, false if it didn't.
263 static bool distribute_processes(uint length, uint* distribution);
264 // Binds the current process to a processor.
265 // Returns true if it worked, false if it didn't.
266 static bool bind_to_processor(uint processor_id);
267
268 // Give a name to the current thread.
269 static void set_native_thread_name(const char *name);
270
271 // Interface for stack banging (predetect possible stack overflow for
272 // exception processing) There are guard pages, and above that shadow
273 // pages for stack overflow checking.
274 static bool uses_stack_guard_pages();
275 static bool must_commit_stack_guard_pages();
276 static void map_stack_shadow_pages(address sp);
277 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
278
279 // OS interface to Virtual Memory
280
281 // Return the default page size.
282 static int vm_page_size();
283
284 // Returns the page size to use for a region of memory.
285 // region_size / min_pages will always be greater than or equal to the
286 // returned value. The returned value will divide region_size.
287 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
288
289 // Returns the page size to use for a region of memory.
290 // region_size / min_pages will always be greater than or equal to the
291 // returned value. The returned value might not divide region_size.
292 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
293
294 // Return the largest page size that can be used
295 static size_t max_page_size() {
296 // The _page_sizes array is sorted in descending order.
297 return _page_sizes[0];
298 }
299
300 // Methods for tracing page sizes returned by the above method.
301 // The region_{min,max}_size parameters should be the values
302 // passed to page_size_for_region() and page_size should be the result of that
303 // call. The (optional) base and size parameters should come from the
304 // ReservedSpace base() and size() methods.
305 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
306 static void trace_page_sizes(const char* str,
307 const size_t region_min_size,
308 const size_t region_max_size,
309 const size_t page_size,
310 const char* base,
311 const size_t size);
312 static void trace_page_sizes_for_requested_size(const char* str,
313 const size_t requested_size,
314 const size_t page_size,
315 const size_t alignment,
316 const char* base,
317 const size_t size);
318
319 static int vm_allocation_granularity();
320 static char* reserve_memory(size_t bytes, char* addr = 0,
321 size_t alignment_hint = 0);
322 static char* reserve_memory(size_t bytes, char* addr,
323 size_t alignment_hint, MEMFLAGS flags);
324 static char* reserve_memory_aligned(size_t size, size_t alignment);
325 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
326 static void split_reserved_memory(char *base, size_t size,
327 size_t split, bool realloc);
328 static bool commit_memory(char* addr, size_t bytes, bool executable);
329 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
330 bool executable);
331 // Same as commit_memory() that either succeeds or calls
332 // vm_exit_out_of_memory() with the specified mesg.
333 static void commit_memory_or_exit(char* addr, size_t bytes,
334 bool executable, const char* mesg);
335 static void commit_memory_or_exit(char* addr, size_t size,
336 size_t alignment_hint,
337 bool executable, const char* mesg);
338 static bool uncommit_memory(char* addr, size_t bytes);
339 static bool release_memory(char* addr, size_t bytes);
340
341 // Touch memory pages that cover the memory range from start to end (exclusive)
342 // to make the OS back the memory range with actual memory.
343 // Current implementation may not touch the last page if unaligned addresses
344 // are passed.
345 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
346
347 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
348 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
349 bool is_committed = true);
350
351 static bool guard_memory(char* addr, size_t bytes);
352 static bool unguard_memory(char* addr, size_t bytes);
353 static bool create_stack_guard_pages(char* addr, size_t bytes);
354 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
355 static bool remove_stack_guard_pages(char* addr, size_t bytes);
356
357 static char* map_memory(int fd, const char* file_name, size_t file_offset,
358 char *addr, size_t bytes, bool read_only = false,
359 bool allow_exec = false);
360 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
361 char *addr, size_t bytes, bool read_only,
362 bool allow_exec);
363 static bool unmap_memory(char *addr, size_t bytes);
364 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
365 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
366
367 // NUMA-specific interface
368 static bool numa_has_static_binding();
369 static bool numa_has_group_homing();
370 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
371 static void numa_make_global(char *addr, size_t bytes);
372 static size_t numa_get_groups_num();
373 static size_t numa_get_leaf_groups(int *ids, size_t size);
374 static bool numa_topology_changed();
375 static int numa_get_group_id();
376
377 // Page manipulation
378 struct page_info {
379 size_t size;
380 int lgrp_id;
381 };
382 static bool get_page_info(char *start, page_info* info);
383 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
384
385 static char* non_memory_address_word();
386 // reserve, commit and pin the entire memory region
387 static char* reserve_memory_special(size_t size, size_t alignment,
388 char* addr, bool executable);
389 static bool release_memory_special(char* addr, size_t bytes);
390 static void large_page_init();
391 static size_t large_page_size();
392 static bool can_commit_large_page_memory();
393 static bool can_execute_large_page_memory();
394
395 // OS interface to polling page
396 static address get_polling_page() { return _polling_page; }
397 static void set_polling_page(address page) { _polling_page = page; }
398 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
399 static void make_polling_page_unreadable();
400 static void make_polling_page_readable();
401
402 // Routines used to serialize the thread state without using membars
403 static void serialize_thread_states();
404
405 // Since we write to the serialize page from every thread, we
406 // want stores to be on unique cache lines whenever possible
407 // in order to minimize CPU cross talk. We pre-compute the
408 // amount to shift the thread* to make this offset unique to
409 // each thread.
410 static int get_serialize_page_shift_count() {
411 return SerializePageShiftCount;
412 }
413
414 static void set_serialize_page_mask(uintptr_t mask) {
415 _serialize_page_mask = mask;
416 }
417
418 static unsigned int get_serialize_page_mask() {
419 return _serialize_page_mask;
420 }
421
422 static void set_memory_serialize_page(address page);
423
424 static address get_memory_serialize_page() {
425 return (address)_mem_serialize_page;
426 }
427
428 static inline void write_memory_serialize_page(JavaThread *thread) {
429 uintptr_t page_offset = ((uintptr_t)thread >>
430 get_serialize_page_shift_count()) &
431 get_serialize_page_mask();
432 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
433 }
434
435 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
436 if (UseMembar) return false;
437 // Previously this function calculated the exact address of this
438 // thread's serialize page, and checked if the faulting address
439 // was equal. However, some platforms mask off faulting addresses
440 // to the page size, so now we just check that the address is
441 // within the page. This makes the thread argument unnecessary,
442 // but we retain the NULL check to preserve existing behavior.
443 if (thread == NULL) return false;
444 address page = (address) _mem_serialize_page;
445 return addr >= page && addr < (page + os::vm_page_size());
446 }
447
448 static void block_on_serialize_page_trap();
449
450 // threads
451
452 enum ThreadType {
453 vm_thread,
454 cgc_thread, // Concurrent GC thread
455 pgc_thread, // Parallel GC thread
456 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads.
457 compiler_thread,
458 watcher_thread,
459 os_thread
460 };
461
462 static bool create_thread(Thread* thread,
463 ThreadType thr_type,
464 size_t req_stack_size = 0);
465 static bool create_main_thread(JavaThread* thread);
466 static bool create_attached_thread(JavaThread* thread);
467 static void pd_start_thread(Thread* thread);
468 static void start_thread(Thread* thread);
469
470 static void initialize_thread(Thread* thr);
471 static void free_thread(OSThread* osthread);
472
473 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
474 static intx current_thread_id();
475 static int current_process_id();
476 static int sleep(Thread* thread, jlong ms, bool interruptable);
477 // Short standalone OS sleep suitable for slow path spin loop.
478 // Ignores Thread.interrupt() (so keep it short).
479 // ms = 0, will sleep for the least amount of time allowed by the OS.
480 static void naked_short_sleep(jlong ms);
481 static void infinite_sleep(); // never returns, use with CAUTION
482 static void naked_yield () ;
483 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
484 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
485
486 static void interrupt(Thread* thread);
487 static bool is_interrupted(Thread* thread, bool clear_interrupted);
488
489 static int pd_self_suspend_thread(Thread* thread);
490
491 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
492 static frame fetch_frame_from_context(const void* ucVoid);
493 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
494
495 static void breakpoint();
496 static bool start_debugging(char *buf, int buflen);
497
498 static address current_stack_pointer();
499 static address current_stack_base();
500 static size_t current_stack_size();
501
502 static void verify_stack_alignment() PRODUCT_RETURN;
503
504 static bool message_box(const char* title, const char* message);
505 static char* do_you_want_to_debug(const char* message);
506
507 // run cmd in a separate process and return its exit code; or -1 on failures
508 static int fork_and_exec(char *cmd);
509
510 // Call ::exit() on all platforms but Windows
511 static void exit(int num);
512
513 // Terminate the VM, but don't exit the process
514 static void shutdown();
515
516 // Terminate with an error. Default is to generate a core file on platforms
517 // that support such things. This calls shutdown() and then aborts.
518 static void abort(bool dump_core, void *siginfo, const void *context);
519 static void abort(bool dump_core = true);
520
521 // Die immediately, no exit hook, no abort hook, no cleanup.
522 static void die();
523
524 // File i/o operations
525 static const int default_file_open_flags();
526 static int open(const char *path, int oflag, int mode);
527 static FILE* open(int fd, const char* mode);
528 static int close(int fd);
529 static jlong lseek(int fd, jlong offset, int whence);
530 static char* native_path(char *path);
531 static int ftruncate(int fd, jlong length);
532 static int fsync(int fd);
533 static int available(int fd, jlong *bytes);
534 static int get_fileno(FILE* fp);
535 static void flockfile(FILE* fp);
536 static void funlockfile(FILE* fp);
537
538 static int compare_file_modified_times(const char* file1, const char* file2);
539
540 //File i/o operations
541
542 static size_t read(int fd, void *buf, unsigned int nBytes);
543 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
544 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
545 static size_t write(int fd, const void *buf, unsigned int nBytes);
546
547 // Reading directories.
548 static DIR* opendir(const char* dirname);
549 static int readdir_buf_size(const char *path);
550 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
551 static int closedir(DIR* dirp);
552
553 // Dynamic library extension
554 static const char* dll_file_extension();
555
556 static const char* get_temp_directory();
557 static const char* get_current_directory(char *buf, size_t buflen);
558
559 // Builds the platform-specific name of a library.
560 // Returns false if the buffer is too small.
561 static bool dll_build_name(char* buffer, size_t size,
562 const char* fname);
563
564 // Builds a platform-specific full library path given an ld path and
565 // unadorned library name. Returns true if the buffer contains a full
566 // path to an existing file, false otherwise. If pathname is empty,
567 // uses the path to the current directory.
568 static bool dll_locate_lib(char* buffer, size_t size,
569 const char* pathname, const char* fname);
570
571 // Symbol lookup, find nearest function name; basically it implements
572 // dladdr() for all platforms. Name of the nearest function is copied
573 // to buf. Distance from its base address is optionally returned as offset.
574 // If function name is not found, buf[0] is set to '\0' and offset is
575 // set to -1 (if offset is non-NULL).
576 static bool dll_address_to_function_name(address addr, char* buf,
577 int buflen, int* offset,
578 bool demangle = true);
579
580 // Locate DLL/DSO. On success, full path of the library is copied to
581 // buf, and offset is optionally set to be the distance between addr
582 // and the library's base address. On failure, buf[0] is set to '\0'
583 // and offset is set to -1 (if offset is non-NULL).
584 static bool dll_address_to_library_name(address addr, char* buf,
585 int buflen, int* offset);
586
587 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
588 static bool address_is_in_vm(address addr);
589
590 // Loads .dll/.so and
591 // in case of error it checks if .dll/.so was built for the
592 // same architecture as HotSpot is running on
593 static void* dll_load(const char *name, char *ebuf, int ebuflen);
594
595 // lookup symbol in a shared library
596 static void* dll_lookup(void* handle, const char* name);
597
598 // Unload library
599 static void dll_unload(void *lib);
600
601 // Callback for loaded module information
602 // Input parameters:
603 // char* module_file_name,
604 // address module_base_addr,
605 // address module_top_addr,
606 // void* param
607 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
608
609 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
610
611 // Return the handle of this process
612 static void* get_default_process_handle();
613
614 // Check for static linked agent library
615 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
616 size_t syms_len);
617
618 // Find agent entry point
619 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
620 const char *syms[], size_t syms_len);
621
622 // Write to stream
623 static int log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
624
625 // Get host name in buffer provided
626 static bool get_host_name(char* buf, size_t buflen);
627
628 // Print out system information; they are called by fatal error handler.
629 // Output format may be different on different platforms.
630 static void print_os_info(outputStream* st);
631 static void print_os_info_brief(outputStream* st);
632 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
633 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
634 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
635 static void print_memory_info(outputStream* st);
636 static void print_dll_info(outputStream* st);
637 static void print_environment_variables(outputStream* st, const char** env_list);
638 static void print_context(outputStream* st, const void* context);
639 static void print_register_info(outputStream* st, const void* context);
640 static void print_siginfo(outputStream* st, const void* siginfo);
641 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
642 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
643
644 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
645 static size_t lasterror(char *buf, size_t len);
646 static int get_last_error();
647
648 // Replacement for strerror().
649 // Will return the english description of the error (e.g. "File not found", as
650 // suggested in the POSIX standard.
651 // Will return "Unknown error" for an unknown errno value.
652 // Will not attempt to localize the returned string.
653 // Will always return a valid string which is a static constant.
654 // Will not change the value of errno.
655 static const char* strerror(int e);
656
657 // Will return the literalized version of the given errno (e.g. "EINVAL"
658 // for EINVAL).
659 // Will return "Unknown error" for an unknown errno value.
660 // Will always return a valid string which is a static constant.
661 // Will not change the value of errno.
662 static const char* errno_name(int e);
663
664 // Determines whether the calling process is being debugged by a user-mode debugger.
665 static bool is_debugger_attached();
666
667 // wait for a key press if PauseAtExit is set
668 static void wait_for_keypress_at_exit(void);
669
670 // The following two functions are used by fatal error handler to trace
671 // native (C) frames. They are not part of frame.hpp/frame.cpp because
672 // frame.hpp/cpp assume thread is JavaThread, and also because different
673 // OS/compiler may have different convention or provide different API to
674 // walk C frames.
675 //
676 // We don't attempt to become a debugger, so we only follow frames if that
677 // does not require a lookup in the unwind table, which is part of the binary
678 // file but may be unsafe to read after a fatal error. So on x86, we can
679 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
680 // possible to walk C stack without having the unwind table.
681 static bool is_first_C_frame(frame *fr);
682 static frame get_sender_for_C_frame(frame *fr);
683
684 // return current frame. pc() and sp() are set to NULL on failure.
685 static frame current_frame();
686
687 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
688
689 // returns a string to describe the exception/signal;
690 // returns NULL if exception_code is not an OS exception/signal.
691 static const char* exception_name(int exception_code, char* buf, size_t buflen);
692
693 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
694 static int get_signal_number(const char* signal_name);
695
696 // Returns native Java library, loads if necessary
697 static void* native_java_library();
698
699 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
700 static void jvm_path(char *buf, jint buflen);
701
702 // Returns true if we are running in a headless jre.
703 static bool is_headless_jre();
704
705 // JNI names
706 static void print_jni_name_prefix_on(outputStream* st, int args_size);
707 static void print_jni_name_suffix_on(outputStream* st, int args_size);
708
709 // Init os specific system properties values
710 static void init_system_properties_values();
711
712 // IO operations, non-JVM_ version.
713 static int stat(const char* path, struct stat* sbuf);
714 static bool dir_is_empty(const char* path);
715
716 // IO operations on binary files
717 static int create_binary_file(const char* path, bool rewrite_existing);
718 static jlong current_file_offset(int fd);
719 static jlong seek_to_file_offset(int fd, jlong offset);
720
721 // Retrieve native stack frames.
722 // Parameter:
723 // stack: an array to storage stack pointers.
724 // frames: size of above array.
725 // toSkip: number of stack frames to skip at the beginning.
726 // Return: number of stack frames captured.
727 static int get_native_stack(address* stack, int size, int toSkip = 0);
728
729 // General allocation (must be MT-safe)
730 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
731 static void* malloc (size_t size, MEMFLAGS flags);
732 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
733 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
734
735 static void free (void *memblock);
736 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
737 // Like strdup, but exit VM when strdup() returns NULL
738 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
739
740 #ifndef PRODUCT
741 static julong num_mallocs; // # of calls to malloc/realloc
742 static julong alloc_bytes; // # of bytes allocated
743 static julong num_frees; // # of calls to free
744 static julong free_bytes; // # of bytes freed
745 #endif
746
747 // SocketInterface (ex HPI SocketInterface )
748 static int socket(int domain, int type, int protocol);
749 static int socket_close(int fd);
750 static int recv(int fd, char* buf, size_t nBytes, uint flags);
751 static int send(int fd, char* buf, size_t nBytes, uint flags);
752 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
753 static int connect(int fd, struct sockaddr* him, socklen_t len);
754 static struct hostent* get_host_by_name(char* name);
755
756 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
757 static void signal_init(TRAPS);
758 static void signal_init_pd();
759 static void signal_notify(int signal_number);
760 static void* signal(int signal_number, void* handler);
761 static void signal_raise(int signal_number);
762 static int signal_wait();
763 static int signal_lookup();
764 static void* user_handler();
765 static void terminate_signal_thread();
766 static int sigexitnum_pd();
767
768 // random number generation
769 static int random(); // return 32bit pseudorandom number
770 static void init_random(unsigned int initval); // initialize random sequence
771
772 // Structured OS Exception support
773 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
774
775 // On Posix compatible OS it will simply check core dump limits while on Windows
776 // it will check if dump file can be created. Check or prepare a core dump to be
777 // taken at a later point in the same thread in os::abort(). Use the caller
778 // provided buffer as a scratch buffer. The status message which will be written
779 // into the error log either is file location or a short error message, depending
780 // on the checking result.
781 static void check_dump_limit(char* buffer, size_t bufferSize);
782
783 // Get the default path to the core file
784 // Returns the length of the string
785 static int get_core_path(char* buffer, size_t bufferSize);
786
787 // JVMTI & JVM monitoring and management support
788 // The thread_cpu_time() and current_thread_cpu_time() are only
789 // supported if is_thread_cpu_time_supported() returns true.
790 // They are not supported on Solaris T1.
791
792 // Thread CPU Time - return the fast estimate on a platform
793 // On Solaris - call gethrvtime (fast) - user time only
794 // On Linux - fast clock_gettime where available - user+sys
795 // - otherwise: very slow /proc fs - user+sys
796 // On Windows - GetThreadTimes - user+sys
797 static jlong current_thread_cpu_time();
798 static jlong thread_cpu_time(Thread* t);
799
800 // Thread CPU Time with user_sys_cpu_time parameter.
801 //
802 // If user_sys_cpu_time is true, user+sys time is returned.
803 // Otherwise, only user time is returned
804 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
805 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
806
807 // Return a bunch of info about the timers.
808 // Note that the returned info for these two functions may be different
809 // on some platforms
810 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
811 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
812
813 static bool is_thread_cpu_time_supported();
814
815 // System loadavg support. Returns -1 if load average cannot be obtained.
816 static int loadavg(double loadavg[], int nelem);
817
818 // Hook for os specific jvm options that we don't want to abort on seeing
819 static bool obsolete_option(const JavaVMOption *option);
820
821 // Amount beyond the callee frame size that we bang the stack.
822 static int extra_bang_size_in_bytes();
823
824 static char** split_path(const char* path, int* n);
825
826 // Extensions
827 #include "runtime/os_ext.hpp"
828
829 public:
830 class CrashProtectionCallback : public StackObj {
831 public:
832 virtual void call() = 0;
833 };
834
835 // Platform dependent stuff
836 #ifndef _WINDOWS
837 # include "os_posix.hpp"
838 #endif
839 #include OS_CPU_HEADER(os)
840 #include OS_HEADER(os)
841
842 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
843 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
844 #endif
845
846 public:
847 #ifndef PLATFORM_PRINT_NATIVE_STACK
848 // No platform-specific code for printing the native stack.
849 static bool platform_print_native_stack(outputStream* st, const void* context,
850 char *buf, int buf_size) {
851 return false;
852 }
853 #endif
854
855 // debugging support (mostly used by debug.cpp but also fatal error handler)
856 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
857
858 static bool dont_yield(); // when true, JVM_Yield() is nop
859 static void print_statistics();
860
861 // Thread priority helpers (implemented in OS-specific part)
862 static OSReturn set_native_priority(Thread* thread, int native_prio);
863 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
864 static int java_to_os_priority[CriticalPriority + 1];
865 // Hint to the underlying OS that a task switch would not be good.
866 // Void return because it's a hint and can fail.
867 static void hint_no_preempt();
868 static const char* native_thread_creation_failed_msg() {
869 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
870 }
871
872 // Used at creation if requested by the diagnostic flag PauseAtStartup.
873 // Causes the VM to wait until an external stimulus has been applied
874 // (for Unix, that stimulus is a signal, for Windows, an external
875 // ResumeThread call)
876 static void pause();
877
878 // Builds a platform dependent Agent_OnLoad_<libname> function name
879 // which is used to find statically linked in agents.
880 static char* build_agent_function_name(const char *sym, const char *cname,
881 bool is_absolute_path);
882
883 class SuspendedThreadTaskContext {
884 public:
885 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
886 Thread* thread() const { return _thread; }
887 void* ucontext() const { return _ucontext; }
888 private:
889 Thread* _thread;
890 void* _ucontext;
891 };
892
893 class SuspendedThreadTask {
894 public:
895 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
896 virtual ~SuspendedThreadTask() {}
897 void run();
898 bool is_done() { return _done; }
899 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
900 protected:
901 private:
902 void internal_do_task();
903 Thread* _thread;
904 bool _done;
905 };
906
907 #ifndef _WINDOWS
908 // Suspend/resume support
909 // Protocol:
910 //
911 // a thread starts in SR_RUNNING
912 //
913 // SR_RUNNING can go to
914 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
915 // SR_SUSPEND_REQUEST can go to
916 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
917 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
918 // SR_SUSPENDED can go to
919 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
920 // SR_WAKEUP_REQUEST can go to
921 // * SR_RUNNING when the stopped thread receives the signal
922 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
923 class SuspendResume {
924 public:
925 enum State {
926 SR_RUNNING,
927 SR_SUSPEND_REQUEST,
928 SR_SUSPENDED,
929 SR_WAKEUP_REQUEST
930 };
931
932 private:
933 volatile State _state;
934
935 private:
936 /* try to switch state from state "from" to state "to"
937 * returns the state set after the method is complete
938 */
939 State switch_state(State from, State to);
940
941 public:
942 SuspendResume() : _state(SR_RUNNING) { }
943
944 State state() const { return _state; }
945
946 State request_suspend() {
947 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
948 }
949
950 State cancel_suspend() {
951 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
952 }
953
954 State suspended() {
955 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
956 }
957
958 State request_wakeup() {
959 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
960 }
961
962 State running() {
963 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
964 }
965
966 bool is_running() const {
967 return _state == SR_RUNNING;
968 }
969
970 bool is_suspend_request() const {
971 return _state == SR_SUSPEND_REQUEST;
972 }
973
974 bool is_suspended() const {
975 return _state == SR_SUSPENDED;
976 }
977 };
978 #endif // !WINDOWS
979
980
981 protected:
982 static volatile unsigned int _rand_seed; // seed for random number generator
983 static int _processor_count; // number of processors
984 static int _initial_active_processor_count; // number of active processors during initialization.
985
986 static char* format_boot_path(const char* format_string,
987 const char* home,
988 int home_len,
989 char fileSep,
990 char pathSep);
991 static bool set_boot_path(char fileSep, char pathSep);
992
993 };
994
995 // Note that "PAUSE" is almost always used with synchronization
996 // so arguably we should provide Atomic::SpinPause() instead
997 // of the global SpinPause() with C linkage.
998 // It'd also be eligible for inlining on many platforms.
999
1000 extern "C" int SpinPause();
1001
1002 #endif // SHARE_VM_RUNTIME_OS_HPP