1 /*
2 * Copyright (c) 1997, 2018, 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 "jvm.h"
29 #include "jvmtifiles/jvmti.h"
30 #include "metaprogramming/isRegisteredEnum.hpp"
31 #include "metaprogramming/integralConstant.hpp"
32 #include "runtime/extendedPC.hpp"
33 #include "utilities/exceptions.hpp"
34 #include "utilities/ostream.hpp"
35 #include "utilities/macros.hpp"
36 #ifndef _WINDOWS
37 # include <setjmp.h>
38 #endif
39 #ifdef __APPLE__
40 # include <mach/mach_time.h>
41 #endif
42
43 class AgentLibrary;
44 class frame;
45
46 // os defines the interface to operating system; this includes traditional
47 // OS services (time, I/O) as well as other functionality with system-
48 // dependent code.
49
50 typedef void (*dll_func)(...);
51
52 class Thread;
53 class JavaThread;
54 class Event;
55 class DLL;
56 class FileHandle;
57 class NativeCallStack;
58 class methodHandle;
59
60 template<class E> class GrowableArray;
61
62 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
63
64 // Platform-independent error return values from OS functions
65 enum OSReturn {
66 OS_OK = 0, // Operation was successful
67 OS_ERR = -1, // Operation failed
68 OS_INTRPT = -2, // Operation was interrupted
69 OS_TIMEOUT = -3, // Operation timed out
70 OS_NOMEM = -5, // Operation failed for lack of memory
71 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
72 };
73
74 enum ThreadPriority { // JLS 20.20.1-3
75 NoPriority = -1, // Initial non-priority value
76 MinPriority = 1, // Minimum priority
77 NormPriority = 5, // Normal (non-daemon) priority
78 NearMaxPriority = 9, // High priority, used for VMThread
79 MaxPriority = 10, // Highest priority, used for WatcherThread
80 // ensures that VMThread doesn't starve profiler
81 CriticalPriority = 11 // Critical thread priority
82 };
83
84 // Executable parameter flag for os::commit_memory() and
85 // os::commit_memory_or_exit().
86 const bool ExecMem = true;
87
88 // Typedef for structured exception handling support
89 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
90
91 class MallocTracker;
92
93 class os: AllStatic {
94 friend class VMStructs;
95 friend class JVMCIVMStructs;
96 friend class MallocTracker;
97 public:
98 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
99
100 private:
101 static OSThread* _starting_thread;
102 static address _polling_page;
103 static volatile int32_t * _mem_serialize_page;
104 static uintptr_t _serialize_page_mask;
105 public:
106 static size_t _page_sizes[page_sizes_max];
107
108 private:
109 static void init_page_sizes(size_t default_page_size) {
110 _page_sizes[0] = default_page_size;
111 _page_sizes[1] = 0; // sentinel
112 }
113
114 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
115 size_t alignment_hint = 0);
116 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
117 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc);
118 static void pd_split_reserved_memory(char *base, size_t size,
119 size_t split, bool realloc);
120 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
121 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
122 bool executable);
123 // Same as pd_commit_memory() that either succeeds or calls
124 // vm_exit_out_of_memory() with the specified mesg.
125 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
126 bool executable, const char* mesg);
127 static void pd_commit_memory_or_exit(char* addr, size_t size,
128 size_t alignment_hint,
129 bool executable, const char* mesg);
130 static bool pd_uncommit_memory(char* addr, size_t bytes);
131 static bool pd_release_memory(char* addr, size_t bytes);
132
133 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
134 char *addr, size_t bytes, bool read_only = false,
135 bool allow_exec = false);
136 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
137 char *addr, size_t bytes, bool read_only,
138 bool allow_exec);
139 static bool pd_unmap_memory(char *addr, size_t bytes);
140 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
141 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
142
143 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
144
145 // Get summary strings for system information in buffer provided
146 static void get_summary_cpu_info(char* buf, size_t buflen);
147 static void get_summary_os_info(char* buf, size_t buflen);
148
149 static void initialize_initial_active_processor_count();
150
151 LINUX_ONLY(static void pd_init_container_support();)
152
153 public:
154 static void init(void); // Called before command line parsing
155
156 static void init_container_support() { // Called during command line parsing.
157 LINUX_ONLY(pd_init_container_support();)
158 }
159
160 static void init_before_ergo(void); // Called after command line parsing
161 // before VM ergonomics processing.
162 static jint init_2(void); // Called after command line parsing
163 // and VM ergonomics processing
164 static void init_globals(void) { // Called from init_globals() in init.cpp
165 init_globals_ext();
166 }
167
168 // File names are case-insensitive on windows only
169 // Override me as needed
170 static int file_name_strcmp(const char* s1, const char* s2);
171
172 // unset environment variable
173 static bool unsetenv(const char* name);
174
175 static bool have_special_privileges();
176
177 static jlong javaTimeMillis();
178 static jlong javaTimeNanos();
179 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
180 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
181 static void run_periodic_checks();
182 static bool supports_monotonic_clock();
183
184 // Returns the elapsed time in seconds since the vm started.
185 static double elapsedTime();
186
187 // Returns real time in seconds since an arbitrary point
188 // in the past.
189 static bool getTimesSecs(double* process_real_time,
190 double* process_user_time,
191 double* process_system_time);
192
193 // Interface to the performance counter
194 static jlong elapsed_counter();
195 static jlong elapsed_frequency();
196
197 // The "virtual time" of a thread is the amount of time a thread has
198 // actually run. The first function indicates whether the OS supports
199 // this functionality for the current thread, and if so:
200 // * the second enables vtime tracking (if that is required).
201 // * the third tells whether vtime is enabled.
202 // * the fourth returns the elapsed virtual time for the current
203 // thread.
204 static bool supports_vtime();
205 static bool enable_vtime();
206 static bool vtime_enabled();
207 static double elapsedVTime();
208
209 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
210 // It is MT safe, but not async-safe, as reading time zone
211 // information may require a lock on some platforms.
212 static char* local_time_string(char *buf, size_t buflen);
213 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
214 static struct tm* gmtime_pd (const time_t* clock, struct tm* res);
215 // Fill in buffer with current local time as an ISO-8601 string.
216 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
217 // Returns buffer, or NULL if it failed.
218 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false);
219
220 // Interface for detecting multiprocessor system
221 static inline bool is_MP() {
222 // During bootstrap if _processor_count is not yet initialized
223 // we claim to be MP as that is safest. If any platform has a
224 // stub generator that might be triggered in this phase and for
225 // which being declared MP when in fact not, is a problem - then
226 // the bootstrap routine for the stub generator needs to check
227 // the processor count directly and leave the bootstrap routine
228 // in place until called after initialization has ocurred.
229 return AssumeMP || (_processor_count != 1);
230 }
231 static julong available_memory();
232 static julong physical_memory();
233 static bool has_allocatable_memory_limit(julong* limit);
234 static bool is_server_class_machine();
235
236 // number of CPUs
237 static int processor_count() {
238 return _processor_count;
239 }
240 static void set_processor_count(int count) { _processor_count = count; }
241
242 // Returns the number of CPUs this process is currently allowed to run on.
243 // Note that on some OSes this can change dynamically.
244 static int active_processor_count();
245
246 // At startup the number of active CPUs this process is allowed to run on.
247 // This value does not change dynamically. May be different from active_processor_count().
248 static int initial_active_processor_count() {
249 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
250 return _initial_active_processor_count;
251 }
252
253 // Bind processes to processors.
254 // This is a two step procedure:
255 // first you generate a distribution of processes to processors,
256 // then you bind processes according to that distribution.
257 // Compute a distribution for number of processes to processors.
258 // Stores the processor id's into the distribution array argument.
259 // Returns true if it worked, false if it didn't.
260 static bool distribute_processes(uint length, uint* distribution);
261 // Binds the current process to a processor.
262 // Returns true if it worked, false if it didn't.
263 static bool bind_to_processor(uint processor_id);
264
265 // Give a name to the current thread.
266 static void set_native_thread_name(const char *name);
267
268 // Interface for stack banging (predetect possible stack overflow for
269 // exception processing) There are guard pages, and above that shadow
270 // pages for stack overflow checking.
271 static bool uses_stack_guard_pages();
272 static bool must_commit_stack_guard_pages();
273 static void map_stack_shadow_pages(address sp);
274 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
275
276 // OS interface to Virtual Memory
277
278 // Return the default page size.
279 static int vm_page_size();
280
281 // Returns the page size to use for a region of memory.
282 // region_size / min_pages will always be greater than or equal to the
283 // returned value. The returned value will divide region_size.
284 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
285
286 // Returns the page size to use for a region of memory.
287 // region_size / min_pages will always be greater than or equal to the
288 // returned value. The returned value might not divide region_size.
289 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
290
291 // Return the largest page size that can be used
292 static size_t max_page_size() {
293 // The _page_sizes array is sorted in descending order.
294 return _page_sizes[0];
295 }
296
297 // Methods for tracing page sizes returned by the above method.
298 // The region_{min,max}_size parameters should be the values
299 // passed to page_size_for_region() and page_size should be the result of that
300 // call. The (optional) base and size parameters should come from the
301 // ReservedSpace base() and size() methods.
302 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
303 static void trace_page_sizes(const char* str,
304 const size_t region_min_size,
305 const size_t region_max_size,
306 const size_t page_size,
307 const char* base,
308 const size_t size);
309 static void trace_page_sizes_for_requested_size(const char* str,
310 const size_t requested_size,
311 const size_t page_size,
312 const size_t alignment,
313 const char* base,
314 const size_t size);
315
316 static int vm_allocation_granularity();
317 static char* reserve_memory(size_t bytes, char* addr = 0,
318 size_t alignment_hint = 0, int file_desc = -1);
319 static char* reserve_memory(size_t bytes, char* addr,
320 size_t alignment_hint, MEMFLAGS flags);
321 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1);
322 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1);
323 static void split_reserved_memory(char *base, size_t size,
324 size_t split, bool realloc);
325 static bool commit_memory(char* addr, size_t bytes, bool executable);
326 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
327 bool executable);
328 // Same as commit_memory() that either succeeds or calls
329 // vm_exit_out_of_memory() with the specified mesg.
330 static void commit_memory_or_exit(char* addr, size_t bytes,
331 bool executable, const char* mesg);
332 static void commit_memory_or_exit(char* addr, size_t size,
333 size_t alignment_hint,
334 bool executable, const char* mesg);
335 static bool uncommit_memory(char* addr, size_t bytes);
336 static bool release_memory(char* addr, size_t bytes);
337
338 // Touch memory pages that cover the memory range from start to end (exclusive)
339 // to make the OS back the memory range with actual memory.
340 // Current implementation may not touch the last page if unaligned addresses
341 // are passed.
342 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
343
344 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
345 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
346 bool is_committed = true);
347
348 static bool guard_memory(char* addr, size_t bytes);
349 static bool unguard_memory(char* addr, size_t bytes);
350 static bool create_stack_guard_pages(char* addr, size_t bytes);
351 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
352 static bool remove_stack_guard_pages(char* addr, size_t bytes);
353 // Helper function to create a new file with template jvmheap.XXXXXX.
354 // Returns a valid fd on success or else returns -1
355 static int create_file_for_heap(const char* dir);
356 // Map memory to the file referred by fd. This function is slightly different from map_memory()
357 // and is added to be used for implementation of -XX:AllocateHeapAt
358 static char* map_memory_to_file(char* base, size_t size, int fd);
359 // Replace existing reserved memory with file mapping
360 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd);
361
362 static char* map_memory(int fd, const char* file_name, size_t file_offset,
363 char *addr, size_t bytes, bool read_only = false,
364 bool allow_exec = false);
365 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
366 char *addr, size_t bytes, bool read_only,
367 bool allow_exec);
368 static bool unmap_memory(char *addr, size_t bytes);
369 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
370 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
371
372 // NUMA-specific interface
373 static bool numa_has_static_binding();
374 static bool numa_has_group_homing();
375 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
376 static void numa_make_global(char *addr, size_t bytes);
377 static size_t numa_get_groups_num();
378 static size_t numa_get_leaf_groups(int *ids, size_t size);
379 static bool numa_topology_changed();
380 static int numa_get_group_id();
381
382 // Page manipulation
383 struct page_info {
384 size_t size;
385 int lgrp_id;
386 };
387 static bool get_page_info(char *start, page_info* info);
388 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
389
390 static char* non_memory_address_word();
391 // reserve, commit and pin the entire memory region
392 static char* reserve_memory_special(size_t size, size_t alignment,
393 char* addr, bool executable);
394 static bool release_memory_special(char* addr, size_t bytes);
395 static void large_page_init();
396 static size_t large_page_size();
397 static bool can_commit_large_page_memory();
398 static bool can_execute_large_page_memory();
399
400 // OS interface to polling page
401 static address get_polling_page() { return _polling_page; }
402 static void set_polling_page(address page) { _polling_page = page; }
403 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
404 static void make_polling_page_unreadable();
405 static void make_polling_page_readable();
406
407 // Routines used to serialize the thread state without using membars
408 static void serialize_thread_states();
409
410 // Since we write to the serialize page from every thread, we
411 // want stores to be on unique cache lines whenever possible
412 // in order to minimize CPU cross talk. We pre-compute the
413 // amount to shift the thread* to make this offset unique to
414 // each thread.
415 static int get_serialize_page_shift_count() {
416 return SerializePageShiftCount;
417 }
418
419 static void set_serialize_page_mask(uintptr_t mask) {
420 _serialize_page_mask = mask;
421 }
422
423 static unsigned int get_serialize_page_mask() {
424 return _serialize_page_mask;
425 }
426
427 static void set_memory_serialize_page(address page);
428
429 static address get_memory_serialize_page() {
430 return (address)_mem_serialize_page;
431 }
432
433 static inline void write_memory_serialize_page(JavaThread *thread) {
434 uintptr_t page_offset = ((uintptr_t)thread >>
435 get_serialize_page_shift_count()) &
436 get_serialize_page_mask();
437 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
438 }
439
440 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
441 if (UseMembar) return false;
442 // Previously this function calculated the exact address of this
443 // thread's serialize page, and checked if the faulting address
444 // was equal. However, some platforms mask off faulting addresses
445 // to the page size, so now we just check that the address is
446 // within the page. This makes the thread argument unnecessary,
447 // but we retain the NULL check to preserve existing behavior.
448 if (thread == NULL) return false;
449 address page = (address) _mem_serialize_page;
450 return addr >= page && addr < (page + os::vm_page_size());
451 }
452
453 static void block_on_serialize_page_trap();
454
455 // threads
456
457 enum ThreadType {
458 vm_thread,
459 cgc_thread, // Concurrent GC thread
460 pgc_thread, // Parallel GC thread
461 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads.
462 compiler_thread,
463 watcher_thread,
464 os_thread
465 };
466
467 static bool create_thread(Thread* thread,
468 ThreadType thr_type,
469 size_t req_stack_size = 0);
470
471 // The "main thread", also known as "starting thread", is the thread
472 // that loads/creates the JVM via JNI_CreateJavaVM.
473 static bool create_main_thread(JavaThread* thread);
474
475 // The primordial thread is the initial process thread. The java
476 // launcher never uses the primordial thread as the main thread, but
477 // applications that host the JVM directly may do so. Some platforms
478 // need special-case handling of the primordial thread if it attaches
479 // to the VM.
480 static bool is_primordial_thread(void)
481 #if defined(_WINDOWS) || defined(BSD)
482 // No way to identify the primordial thread.
483 { return false; }
484 #else
485 ;
486 #endif
487
488 static bool create_attached_thread(JavaThread* thread);
489 static void pd_start_thread(Thread* thread);
490 static void start_thread(Thread* thread);
491
492 static void initialize_thread(Thread* thr);
493 static void free_thread(OSThread* osthread);
494
495 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
496 static intx current_thread_id();
497 static int current_process_id();
498 static int sleep(Thread* thread, jlong ms, bool interruptable);
499 // Short standalone OS sleep suitable for slow path spin loop.
500 // Ignores Thread.interrupt() (so keep it short).
501 // ms = 0, will sleep for the least amount of time allowed by the OS.
502 static void naked_short_sleep(jlong ms);
503 static void infinite_sleep(); // never returns, use with CAUTION
504 static void naked_yield () ;
505 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
506 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
507
508 static void interrupt(Thread* thread);
509 static bool is_interrupted(Thread* thread, bool clear_interrupted);
510
511 static int pd_self_suspend_thread(Thread* thread);
512
513 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
514 static frame fetch_frame_from_context(const void* ucVoid);
515 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
516
517 static void breakpoint();
518 static bool start_debugging(char *buf, int buflen);
519
520 static address current_stack_pointer();
521 static address current_stack_base();
522 static size_t current_stack_size();
523
524 static void verify_stack_alignment() PRODUCT_RETURN;
525
526 static bool message_box(const char* title, const char* message);
527 static char* do_you_want_to_debug(const char* message);
528
529 // run cmd in a separate process and return its exit code; or -1 on failures
530 static int fork_and_exec(char *cmd);
531
532 // Call ::exit() on all platforms but Windows
533 static void exit(int num);
534
535 // Terminate the VM, but don't exit the process
536 static void shutdown();
537
538 // Terminate with an error. Default is to generate a core file on platforms
539 // that support such things. This calls shutdown() and then aborts.
540 static void abort(bool dump_core, void *siginfo, const void *context);
541 static void abort(bool dump_core = true);
542
543 // Die immediately, no exit hook, no abort hook, no cleanup.
544 static void die();
545
546 // File i/o operations
547 static const int default_file_open_flags();
548 static int open(const char *path, int oflag, int mode);
549 static FILE* open(int fd, const char* mode);
550 static FILE* fopen(const char* path, const char* mode);
551 static int close(int fd);
552 static jlong lseek(int fd, jlong offset, int whence);
553 static char* native_path(char *path);
554 static int ftruncate(int fd, jlong length);
555 static int fsync(int fd);
556 static int available(int fd, jlong *bytes);
557 static int get_fileno(FILE* fp);
558 static void flockfile(FILE* fp);
559 static void funlockfile(FILE* fp);
560
561 static int compare_file_modified_times(const char* file1, const char* file2);
562
563 //File i/o operations
564
565 static size_t read(int fd, void *buf, unsigned int nBytes);
566 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
567 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
568 static size_t write(int fd, const void *buf, unsigned int nBytes);
569
570 // Reading directories.
571 static DIR* opendir(const char* dirname);
572 static int readdir_buf_size(const char *path);
573 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
574 static int closedir(DIR* dirp);
575
576 // Dynamic library extension
577 static const char* dll_file_extension();
578
579 static const char* get_temp_directory();
580 static const char* get_current_directory(char *buf, size_t buflen);
581
582 // Builds the platform-specific name of a library.
583 // Returns false if the buffer is too small.
584 static bool dll_build_name(char* buffer, size_t size,
585 const char* fname);
586
587 // Builds a platform-specific full library path given an ld path and
588 // unadorned library name. Returns true if the buffer contains a full
589 // path to an existing file, false otherwise. If pathname is empty,
590 // uses the path to the current directory.
591 static bool dll_locate_lib(char* buffer, size_t size,
592 const char* pathname, const char* fname);
593
594 // Symbol lookup, find nearest function name; basically it implements
595 // dladdr() for all platforms. Name of the nearest function is copied
596 // to buf. Distance from its base address is optionally returned as offset.
597 // If function name is not found, buf[0] is set to '\0' and offset is
598 // set to -1 (if offset is non-NULL).
599 static bool dll_address_to_function_name(address addr, char* buf,
600 int buflen, int* offset,
601 bool demangle = true);
602
603 // Locate DLL/DSO. On success, full path of the library is copied to
604 // buf, and offset is optionally set to be the distance between addr
605 // and the library's base address. On failure, buf[0] is set to '\0'
606 // and offset is set to -1 (if offset is non-NULL).
607 static bool dll_address_to_library_name(address addr, char* buf,
608 int buflen, int* offset);
609
610 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
611 static bool address_is_in_vm(address addr);
612
613 // Loads .dll/.so and
614 // in case of error it checks if .dll/.so was built for the
615 // same architecture as HotSpot is running on
616 static void* dll_load(const char *name, char *ebuf, int ebuflen);
617
618 // lookup symbol in a shared library
619 static void* dll_lookup(void* handle, const char* name);
620
621 // Unload library
622 static void dll_unload(void *lib);
623
624 // Callback for loaded module information
625 // Input parameters:
626 // char* module_file_name,
627 // address module_base_addr,
628 // address module_top_addr,
629 // void* param
630 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
631
632 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
633
634 // Return the handle of this process
635 static void* get_default_process_handle();
636
637 // Check for static linked agent library
638 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
639 size_t syms_len);
640
641 // Find agent entry point
642 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
643 const char *syms[], size_t syms_len);
644
645 // Provide C99 compliant versions of these functions, since some versions
646 // of some platforms don't.
647 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
648 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
649
650 // Get host name in buffer provided
651 static bool get_host_name(char* buf, size_t buflen);
652
653 // Print out system information; they are called by fatal error handler.
654 // Output format may be different on different platforms.
655 static void print_os_info(outputStream* st);
656 static void print_os_info_brief(outputStream* st);
657 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
658 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
659 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
660 static void print_memory_info(outputStream* st);
661 static void print_dll_info(outputStream* st);
662 static void print_environment_variables(outputStream* st, const char** env_list);
663 static void print_context(outputStream* st, const void* context);
664 static void print_register_info(outputStream* st, const void* context);
665 static void print_siginfo(outputStream* st, const void* siginfo);
666 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
667 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
668
669 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
670 static size_t lasterror(char *buf, size_t len);
671 static int get_last_error();
672
673 // Replacement for strerror().
674 // Will return the english description of the error (e.g. "File not found", as
675 // suggested in the POSIX standard.
676 // Will return "Unknown error" for an unknown errno value.
677 // Will not attempt to localize the returned string.
678 // Will always return a valid string which is a static constant.
679 // Will not change the value of errno.
680 static const char* strerror(int e);
681
682 // Will return the literalized version of the given errno (e.g. "EINVAL"
683 // for EINVAL).
684 // Will return "Unknown error" for an unknown errno value.
685 // Will always return a valid string which is a static constant.
686 // Will not change the value of errno.
687 static const char* errno_name(int e);
688
689 // Determines whether the calling process is being debugged by a user-mode debugger.
690 static bool is_debugger_attached();
691
692 // wait for a key press if PauseAtExit is set
693 static void wait_for_keypress_at_exit(void);
694
695 // The following two functions are used by fatal error handler to trace
696 // native (C) frames. They are not part of frame.hpp/frame.cpp because
697 // frame.hpp/cpp assume thread is JavaThread, and also because different
698 // OS/compiler may have different convention or provide different API to
699 // walk C frames.
700 //
701 // We don't attempt to become a debugger, so we only follow frames if that
702 // does not require a lookup in the unwind table, which is part of the binary
703 // file but may be unsafe to read after a fatal error. So on x86, we can
704 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
705 // possible to walk C stack without having the unwind table.
706 static bool is_first_C_frame(frame *fr);
707 static frame get_sender_for_C_frame(frame *fr);
708
709 // return current frame. pc() and sp() are set to NULL on failure.
710 static frame current_frame();
711
712 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
713
714 // returns a string to describe the exception/signal;
715 // returns NULL if exception_code is not an OS exception/signal.
716 static const char* exception_name(int exception_code, char* buf, size_t buflen);
717
718 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
719 static int get_signal_number(const char* signal_name);
720
721 // Returns native Java library, loads if necessary
722 static void* native_java_library();
723
724 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
725 static void jvm_path(char *buf, jint buflen);
726
727 // JNI names
728 static void print_jni_name_prefix_on(outputStream* st, int args_size);
729 static void print_jni_name_suffix_on(outputStream* st, int args_size);
730
731 // Init os specific system properties values
732 static void init_system_properties_values();
733
734 // IO operations, non-JVM_ version.
735 static int stat(const char* path, struct stat* sbuf);
736 static bool dir_is_empty(const char* path);
737
738 // IO operations on binary files
739 static int create_binary_file(const char* path, bool rewrite_existing);
740 static jlong current_file_offset(int fd);
741 static jlong seek_to_file_offset(int fd, jlong offset);
742
743 // Retrieve native stack frames.
744 // Parameter:
745 // stack: an array to storage stack pointers.
746 // frames: size of above array.
747 // toSkip: number of stack frames to skip at the beginning.
748 // Return: number of stack frames captured.
749 static int get_native_stack(address* stack, int size, int toSkip = 0);
750
751 // General allocation (must be MT-safe)
752 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
753 static void* malloc (size_t size, MEMFLAGS flags);
754 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
755 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
756
757 static void free (void *memblock);
758 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
759 // Like strdup, but exit VM when strdup() returns NULL
760 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
761
762 #ifndef PRODUCT
763 static julong num_mallocs; // # of calls to malloc/realloc
764 static julong alloc_bytes; // # of bytes allocated
765 static julong num_frees; // # of calls to free
766 static julong free_bytes; // # of bytes freed
767 #endif
768
769 // SocketInterface (ex HPI SocketInterface )
770 static int socket(int domain, int type, int protocol);
771 static int socket_close(int fd);
772 static int recv(int fd, char* buf, size_t nBytes, uint flags);
773 static int send(int fd, char* buf, size_t nBytes, uint flags);
774 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
775 static int connect(int fd, struct sockaddr* him, socklen_t len);
776 static struct hostent* get_host_by_name(char* name);
777
778 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
779 static void signal_init(TRAPS);
780 static void signal_init_pd();
781 static void signal_notify(int signal_number);
782 static void* signal(int signal_number, void* handler);
783 static void signal_raise(int signal_number);
784 static int signal_wait();
785 static void* user_handler();
786 static void terminate_signal_thread();
787 static int sigexitnum_pd();
788
789 // random number generation
790 static int random(); // return 32bit pseudorandom number
791 static void init_random(unsigned int initval); // initialize random sequence
792
793 // Structured OS Exception support
794 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
795
796 // On Posix compatible OS it will simply check core dump limits while on Windows
797 // it will check if dump file can be created. Check or prepare a core dump to be
798 // taken at a later point in the same thread in os::abort(). Use the caller
799 // provided buffer as a scratch buffer. The status message which will be written
800 // into the error log either is file location or a short error message, depending
801 // on the checking result.
802 static void check_dump_limit(char* buffer, size_t bufferSize);
803
804 // Get the default path to the core file
805 // Returns the length of the string
806 static int get_core_path(char* buffer, size_t bufferSize);
807
808 // JVMTI & JVM monitoring and management support
809 // The thread_cpu_time() and current_thread_cpu_time() are only
810 // supported if is_thread_cpu_time_supported() returns true.
811 // They are not supported on Solaris T1.
812
813 // Thread CPU Time - return the fast estimate on a platform
814 // On Solaris - call gethrvtime (fast) - user time only
815 // On Linux - fast clock_gettime where available - user+sys
816 // - otherwise: very slow /proc fs - user+sys
817 // On Windows - GetThreadTimes - user+sys
818 static jlong current_thread_cpu_time();
819 static jlong thread_cpu_time(Thread* t);
820
821 // Thread CPU Time with user_sys_cpu_time parameter.
822 //
823 // If user_sys_cpu_time is true, user+sys time is returned.
824 // Otherwise, only user time is returned
825 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
826 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
827
828 // Return a bunch of info about the timers.
829 // Note that the returned info for these two functions may be different
830 // on some platforms
831 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
832 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
833
834 static bool is_thread_cpu_time_supported();
835
836 // System loadavg support. Returns -1 if load average cannot be obtained.
837 static int loadavg(double loadavg[], int nelem);
838
839 // Hook for os specific jvm options that we don't want to abort on seeing
840 static bool obsolete_option(const JavaVMOption *option);
841
842 // Amount beyond the callee frame size that we bang the stack.
843 static int extra_bang_size_in_bytes();
844
845 static char** split_path(const char* path, int* n);
846
847 // Extensions
848 #include "runtime/os_ext.hpp"
849
850 public:
851 class CrashProtectionCallback : public StackObj {
852 public:
853 virtual void call() = 0;
854 };
855
856 // Platform dependent stuff
857 #ifndef _WINDOWS
858 # include "os_posix.hpp"
859 #endif
860 #include OS_CPU_HEADER(os)
861 #include OS_HEADER(os)
862
863 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
864 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
865 #endif
866
867 public:
868 #ifndef PLATFORM_PRINT_NATIVE_STACK
869 // No platform-specific code for printing the native stack.
870 static bool platform_print_native_stack(outputStream* st, const void* context,
871 char *buf, int buf_size) {
872 return false;
873 }
874 #endif
875
876 // debugging support (mostly used by debug.cpp but also fatal error handler)
877 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
878
879 static bool dont_yield(); // when true, JVM_Yield() is nop
880 static void print_statistics();
881
882 // Thread priority helpers (implemented in OS-specific part)
883 static OSReturn set_native_priority(Thread* thread, int native_prio);
884 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
885 static int java_to_os_priority[CriticalPriority + 1];
886 // Hint to the underlying OS that a task switch would not be good.
887 // Void return because it's a hint and can fail.
888 static void hint_no_preempt();
889 static const char* native_thread_creation_failed_msg() {
890 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
891 }
892
893 // Used at creation if requested by the diagnostic flag PauseAtStartup.
894 // Causes the VM to wait until an external stimulus has been applied
895 // (for Unix, that stimulus is a signal, for Windows, an external
896 // ResumeThread call)
897 static void pause();
898
899 // Builds a platform dependent Agent_OnLoad_<libname> function name
900 // which is used to find statically linked in agents.
901 static char* build_agent_function_name(const char *sym, const char *cname,
902 bool is_absolute_path);
903
904 class SuspendedThreadTaskContext {
905 public:
906 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
907 Thread* thread() const { return _thread; }
908 void* ucontext() const { return _ucontext; }
909 private:
910 Thread* _thread;
911 void* _ucontext;
912 };
913
914 class SuspendedThreadTask {
915 public:
916 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
917 void run();
918 bool is_done() { return _done; }
919 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
920 protected:
921 ~SuspendedThreadTask() {}
922 private:
923 void internal_do_task();
924 Thread* _thread;
925 bool _done;
926 };
927
928 #ifndef _WINDOWS
929 // Suspend/resume support
930 // Protocol:
931 //
932 // a thread starts in SR_RUNNING
933 //
934 // SR_RUNNING can go to
935 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
936 // SR_SUSPEND_REQUEST can go to
937 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
938 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
939 // SR_SUSPENDED can go to
940 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
941 // SR_WAKEUP_REQUEST can go to
942 // * SR_RUNNING when the stopped thread receives the signal
943 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
944 class SuspendResume {
945 public:
946 enum State {
947 SR_RUNNING,
948 SR_SUSPEND_REQUEST,
949 SR_SUSPENDED,
950 SR_WAKEUP_REQUEST
951 };
952
953 private:
954 volatile State _state;
955
956 private:
957 /* try to switch state from state "from" to state "to"
958 * returns the state set after the method is complete
959 */
960 State switch_state(State from, State to);
961
962 public:
963 SuspendResume() : _state(SR_RUNNING) { }
964
965 State state() const { return _state; }
966
967 State request_suspend() {
968 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
969 }
970
971 State cancel_suspend() {
972 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
973 }
974
975 State suspended() {
976 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
977 }
978
979 State request_wakeup() {
980 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
981 }
982
983 State running() {
984 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
985 }
986
987 bool is_running() const {
988 return _state == SR_RUNNING;
989 }
990
991 bool is_suspend_request() const {
992 return _state == SR_SUSPEND_REQUEST;
993 }
994
995 bool is_suspended() const {
996 return _state == SR_SUSPENDED;
997 }
998 };
999 #endif // !WINDOWS
1000
1001
1002 protected:
1003 static volatile unsigned int _rand_seed; // seed for random number generator
1004 static int _processor_count; // number of processors
1005 static int _initial_active_processor_count; // number of active processors during initialization.
1006
1007 static char* format_boot_path(const char* format_string,
1008 const char* home,
1009 int home_len,
1010 char fileSep,
1011 char pathSep);
1012 static bool set_boot_path(char fileSep, char pathSep);
1013
1014 };
1015
1016 #ifndef _WINDOWS
1017 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {};
1018 #endif // !_WINDOWS
1019
1020 // Note that "PAUSE" is almost always used with synchronization
1021 // so arguably we should provide Atomic::SpinPause() instead
1022 // of the global SpinPause() with C linkage.
1023 // It'd also be eligible for inlining on many platforms.
1024
1025 extern "C" int SpinPause();
1026
1027 #endif // SHARE_VM_RUNTIME_OS_HPP