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_strncmp(const char* s1, const char* s2, size_t num);
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 // Returns the id of the processor on which the calling thread is currently executing.
237 // The returned value is guaranteed to be between 0 and (os::processor_count() - 1).
238 static uint processor_id();
239
240 // number of CPUs
241 static int processor_count() {
242 return _processor_count;
243 }
244 static void set_processor_count(int count) { _processor_count = count; }
245
246 // Returns the number of CPUs this process is currently allowed to run on.
247 // Note that on some OSes this can change dynamically.
248 static int active_processor_count();
249
250 // At startup the number of active CPUs this process is allowed to run on.
251 // This value does not change dynamically. May be different from active_processor_count().
252 static int initial_active_processor_count() {
253 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
254 return _initial_active_processor_count;
255 }
256
257 // Bind processes to processors.
258 // This is a two step procedure:
259 // first you generate a distribution of processes to processors,
260 // then you bind processes according to that distribution.
261 // Compute a distribution for number of processes to processors.
262 // Stores the processor id's into the distribution array argument.
263 // Returns true if it worked, false if it didn't.
264 static bool distribute_processes(uint length, uint* distribution);
265 // Binds the current process to a processor.
266 // Returns true if it worked, false if it didn't.
267 static bool bind_to_processor(uint processor_id);
268
269 // Give a name to the current thread.
270 static void set_native_thread_name(const char *name);
271
272 // Interface for stack banging (predetect possible stack overflow for
273 // exception processing) There are guard pages, and above that shadow
274 // pages for stack overflow checking.
275 static bool uses_stack_guard_pages();
276 static bool must_commit_stack_guard_pages();
277 static void map_stack_shadow_pages(address sp);
278 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
279
280 // Find committed memory region within specified range (start, start + size),
281 // return true if found any
282 static bool committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size);
283
284 // OS interface to Virtual Memory
285
286 // Return the default page size.
287 static int vm_page_size();
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 will divide region_size.
292 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
293
294 // Returns the page size to use for a region of memory.
295 // region_size / min_pages will always be greater than or equal to the
296 // returned value. The returned value might not divide region_size.
297 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
298
299 // Return the largest page size that can be used
300 static size_t max_page_size() {
301 // The _page_sizes array is sorted in descending order.
302 return _page_sizes[0];
303 }
304
305 // Methods for tracing page sizes returned by the above method.
306 // The region_{min,max}_size parameters should be the values
307 // passed to page_size_for_region() and page_size should be the result of that
308 // call. The (optional) base and size parameters should come from the
309 // ReservedSpace base() and size() methods.
310 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
311 static void trace_page_sizes(const char* str,
312 const size_t region_min_size,
313 const size_t region_max_size,
314 const size_t page_size,
315 const char* base,
316 const size_t size);
317 static void trace_page_sizes_for_requested_size(const char* str,
318 const size_t requested_size,
319 const size_t page_size,
320 const size_t alignment,
321 const char* base,
322 const size_t size);
323
324 static int vm_allocation_granularity();
325 static char* reserve_memory(size_t bytes, char* addr = 0,
326 size_t alignment_hint = 0, int file_desc = -1);
327 static char* reserve_memory(size_t bytes, char* addr,
328 size_t alignment_hint, MEMFLAGS flags);
329 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1);
330 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1);
331 static void split_reserved_memory(char *base, size_t size,
332 size_t split, bool realloc);
333 static bool commit_memory(char* addr, size_t bytes, bool executable);
334 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
335 bool executable);
336 // Same as commit_memory() that either succeeds or calls
337 // vm_exit_out_of_memory() with the specified mesg.
338 static void commit_memory_or_exit(char* addr, size_t bytes,
339 bool executable, const char* mesg);
340 static void commit_memory_or_exit(char* addr, size_t size,
341 size_t alignment_hint,
342 bool executable, const char* mesg);
343 static bool uncommit_memory(char* addr, size_t bytes);
344 static bool release_memory(char* addr, size_t bytes);
345
346 // Touch memory pages that cover the memory range from start to end (exclusive)
347 // to make the OS back the memory range with actual memory.
348 // Current implementation may not touch the last page if unaligned addresses
349 // are passed.
350 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
351
352 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
353 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
354 bool is_committed = true);
355
356 static bool guard_memory(char* addr, size_t bytes);
357 static bool unguard_memory(char* addr, size_t bytes);
358 static bool create_stack_guard_pages(char* addr, size_t bytes);
359 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
360 static bool remove_stack_guard_pages(char* addr, size_t bytes);
361 // Helper function to create a new file with template jvmheap.XXXXXX.
362 // Returns a valid fd on success or else returns -1
363 static int create_file_for_heap(const char* dir);
364 // Map memory to the file referred by fd. This function is slightly different from map_memory()
365 // and is added to be used for implementation of -XX:AllocateHeapAt
366 static char* map_memory_to_file(char* base, size_t size, int fd);
367 // Replace existing reserved memory with file mapping
368 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd);
369
370 static char* map_memory(int fd, const char* file_name, size_t file_offset,
371 char *addr, size_t bytes, bool read_only = false,
372 bool allow_exec = false);
373 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
374 char *addr, size_t bytes, bool read_only,
375 bool allow_exec);
376 static bool unmap_memory(char *addr, size_t bytes);
377 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
378 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
379
380 // NUMA-specific interface
381 static bool numa_has_static_binding();
382 static bool numa_has_group_homing();
383 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
384 static void numa_make_global(char *addr, size_t bytes);
385 static size_t numa_get_groups_num();
386 static size_t numa_get_leaf_groups(int *ids, size_t size);
387 static bool numa_topology_changed();
388 static int numa_get_group_id();
389
390 // Page manipulation
391 struct page_info {
392 size_t size;
393 int lgrp_id;
394 };
395 static bool get_page_info(char *start, page_info* info);
396 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
397
398 static char* non_memory_address_word();
399 // reserve, commit and pin the entire memory region
400 static char* reserve_memory_special(size_t size, size_t alignment,
401 char* addr, bool executable);
402 static bool release_memory_special(char* addr, size_t bytes);
403 static void large_page_init();
404 static size_t large_page_size();
405 static bool can_commit_large_page_memory();
406 static bool can_execute_large_page_memory();
407
408 // OS interface to polling page
409 static address get_polling_page() { return _polling_page; }
410 static void set_polling_page(address page) { _polling_page = page; }
411 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
412 static void make_polling_page_unreadable();
413 static void make_polling_page_readable();
414
415 // Check if pointer points to readable memory (by 4-byte read access)
416 static bool is_readable_pointer(const void* p);
417
418 // Routines used to serialize the thread state without using membars
419 static void serialize_thread_states();
420
421 // Since we write to the serialize page from every thread, we
422 // want stores to be on unique cache lines whenever possible
423 // in order to minimize CPU cross talk. We pre-compute the
424 // amount to shift the thread* to make this offset unique to
425 // each thread.
426 static int get_serialize_page_shift_count() {
427 return SerializePageShiftCount;
428 }
429
430 static void set_serialize_page_mask(uintptr_t mask) {
431 _serialize_page_mask = mask;
432 }
433
434 static unsigned int get_serialize_page_mask() {
435 return _serialize_page_mask;
436 }
437
438 static void set_memory_serialize_page(address page);
439
440 static address get_memory_serialize_page() {
441 return (address)_mem_serialize_page;
442 }
443
444 static inline void write_memory_serialize_page(JavaThread *thread) {
445 uintptr_t page_offset = ((uintptr_t)thread >>
446 get_serialize_page_shift_count()) &
447 get_serialize_page_mask();
448 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
449 }
450
451 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
452 if (UseMembar) return false;
453 // Previously this function calculated the exact address of this
454 // thread's serialize page, and checked if the faulting address
455 // was equal. However, some platforms mask off faulting addresses
456 // to the page size, so now we just check that the address is
457 // within the page. This makes the thread argument unnecessary,
458 // but we retain the NULL check to preserve existing behavior.
459 if (thread == NULL) return false;
460 address page = (address) _mem_serialize_page;
461 return addr >= page && addr < (page + os::vm_page_size());
462 }
463
464 static void block_on_serialize_page_trap();
465
466 // threads
467
468 enum ThreadType {
469 vm_thread,
470 cgc_thread, // Concurrent GC thread
471 pgc_thread, // Parallel GC thread
472 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads.
473 compiler_thread,
474 watcher_thread,
475 os_thread
476 };
477
478 static bool create_thread(Thread* thread,
479 ThreadType thr_type,
480 size_t req_stack_size = 0);
481
482 // The "main thread", also known as "starting thread", is the thread
483 // that loads/creates the JVM via JNI_CreateJavaVM.
484 static bool create_main_thread(JavaThread* thread);
485
486 // The primordial thread is the initial process thread. The java
487 // launcher never uses the primordial thread as the main thread, but
488 // applications that host the JVM directly may do so. Some platforms
489 // need special-case handling of the primordial thread if it attaches
490 // to the VM.
491 static bool is_primordial_thread(void)
492 #if defined(_WINDOWS) || defined(BSD)
493 // No way to identify the primordial thread.
494 { return false; }
495 #else
496 ;
497 #endif
498
499 static bool create_attached_thread(JavaThread* thread);
500 static void pd_start_thread(Thread* thread);
501 static void start_thread(Thread* thread);
502
503 static void initialize_thread(Thread* thr);
504 static void free_thread(OSThread* osthread);
505
506 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
507 static intx current_thread_id();
508 static int current_process_id();
509 static int sleep(Thread* thread, jlong ms, bool interruptable);
510 // Short standalone OS sleep suitable for slow path spin loop.
511 // Ignores Thread.interrupt() (so keep it short).
512 // ms = 0, will sleep for the least amount of time allowed by the OS.
513 static void naked_short_sleep(jlong ms);
514 static void infinite_sleep(); // never returns, use with CAUTION
515 static void naked_yield () ;
516 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
517 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
518
519 static void interrupt(Thread* thread);
520 static bool is_interrupted(Thread* thread, bool clear_interrupted);
521
522 static int pd_self_suspend_thread(Thread* thread);
523
524 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
525 static frame fetch_frame_from_context(const void* ucVoid);
526 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
527
528 static void breakpoint();
529 static bool start_debugging(char *buf, int buflen);
530
531 static address current_stack_pointer();
532 static address current_stack_base();
533 static size_t current_stack_size();
534
535 static void verify_stack_alignment() PRODUCT_RETURN;
536
537 static bool message_box(const char* title, const char* message);
538 static char* do_you_want_to_debug(const char* message);
539
540 // run cmd in a separate process and return its exit code; or -1 on failures
541 static int fork_and_exec(char *cmd);
542
543 // Call ::exit() on all platforms but Windows
544 static void exit(int num);
545
546 // Terminate the VM, but don't exit the process
547 static void shutdown();
548
549 // Terminate with an error. Default is to generate a core file on platforms
550 // that support such things. This calls shutdown() and then aborts.
551 static void abort(bool dump_core, void *siginfo, const void *context);
552 static void abort(bool dump_core = true);
553
554 // Die immediately, no exit hook, no abort hook, no cleanup.
555 static void die();
556
557 // File i/o operations
558 static const int default_file_open_flags();
559 static int open(const char *path, int oflag, int mode);
560 static FILE* open(int fd, const char* mode);
561 static FILE* fopen(const char* path, const char* mode);
562 static int close(int fd);
563 static jlong lseek(int fd, jlong offset, int whence);
564 // This function, on Windows, canonicalizes a given path (see os_windows.cpp for details).
565 // On Posix, this function is a noop: it does not change anything and just returns
566 // the input pointer.
567 static char* native_path(char *path);
568 static int ftruncate(int fd, jlong length);
569 static int fsync(int fd);
570 static int available(int fd, jlong *bytes);
571 static int get_fileno(FILE* fp);
572 static void flockfile(FILE* fp);
573 static void funlockfile(FILE* fp);
574
575 static int compare_file_modified_times(const char* file1, const char* file2);
576
577 //File i/o operations
578
579 static size_t read(int fd, void *buf, unsigned int nBytes);
580 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
581 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
582 static size_t write(int fd, const void *buf, unsigned int nBytes);
583
584 // Reading directories.
585 static DIR* opendir(const char* dirname);
586 static struct dirent* readdir(DIR* dirp);
587 static int closedir(DIR* dirp);
588
589 // Dynamic library extension
590 static const char* dll_file_extension();
591
592 static const char* get_temp_directory();
593 static const char* get_current_directory(char *buf, size_t buflen);
594
595 // Builds the platform-specific name of a library.
596 // Returns false if the buffer is too small.
597 static bool dll_build_name(char* buffer, size_t size,
598 const char* fname);
599
600 // Builds a platform-specific full library path given an ld path and
601 // unadorned library name. Returns true if the buffer contains a full
602 // path to an existing file, false otherwise. If pathname is empty,
603 // uses the path to the current directory.
604 static bool dll_locate_lib(char* buffer, size_t size,
605 const char* pathname, const char* fname);
606
607 // Symbol lookup, find nearest function name; basically it implements
608 // dladdr() for all platforms. Name of the nearest function is copied
609 // to buf. Distance from its base address is optionally returned as offset.
610 // If function name is not found, buf[0] is set to '\0' and offset is
611 // set to -1 (if offset is non-NULL).
612 static bool dll_address_to_function_name(address addr, char* buf,
613 int buflen, int* offset,
614 bool demangle = true);
615
616 // Locate DLL/DSO. On success, full path of the library is copied to
617 // buf, and offset is optionally set to be the distance between addr
618 // and the library's base address. On failure, buf[0] is set to '\0'
619 // and offset is set to -1 (if offset is non-NULL).
620 static bool dll_address_to_library_name(address addr, char* buf,
621 int buflen, int* offset);
622
623 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
624 static bool address_is_in_vm(address addr);
625
626 // Loads .dll/.so and
627 // in case of error it checks if .dll/.so was built for the
628 // same architecture as HotSpot is running on
629 static void* dll_load(const char *name, char *ebuf, int ebuflen);
630
631 // lookup symbol in a shared library
632 static void* dll_lookup(void* handle, const char* name);
633
634 // Unload library
635 static void dll_unload(void *lib);
636
637 // Callback for loaded module information
638 // Input parameters:
639 // char* module_file_name,
640 // address module_base_addr,
641 // address module_top_addr,
642 // void* param
643 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
644
645 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
646
647 // Return the handle of this process
648 static void* get_default_process_handle();
649
650 // Check for static linked agent library
651 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
652 size_t syms_len);
653
654 // Find agent entry point
655 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
656 const char *syms[], size_t syms_len);
657
658 // Provide C99 compliant versions of these functions, since some versions
659 // of some platforms don't.
660 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
661 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
662
663 // Get host name in buffer provided
664 static bool get_host_name(char* buf, size_t buflen);
665
666 // Print out system information; they are called by fatal error handler.
667 // Output format may be different on different platforms.
668 static void print_os_info(outputStream* st);
669 static void print_os_info_brief(outputStream* st);
670 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
671 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
672 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
673 static void print_memory_info(outputStream* st);
674 static void print_dll_info(outputStream* st);
675 static void print_environment_variables(outputStream* st, const char** env_list);
676 static void print_context(outputStream* st, const void* context);
677 static void print_register_info(outputStream* st, const void* context);
678 static void print_siginfo(outputStream* st, const void* siginfo);
679 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
680 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
681
682 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
683 static size_t lasterror(char *buf, size_t len);
684 static int get_last_error();
685
686 // Replacement for strerror().
687 // Will return the english description of the error (e.g. "File not found", as
688 // suggested in the POSIX standard.
689 // Will return "Unknown error" for an unknown errno value.
690 // Will not attempt to localize the returned string.
691 // Will always return a valid string which is a static constant.
692 // Will not change the value of errno.
693 static const char* strerror(int e);
694
695 // Will return the literalized version of the given errno (e.g. "EINVAL"
696 // for EINVAL).
697 // Will return "Unknown error" for an unknown errno value.
698 // Will always return a valid string which is a static constant.
699 // Will not change the value of errno.
700 static const char* errno_name(int e);
701
702 // Determines whether the calling process is being debugged by a user-mode debugger.
703 static bool is_debugger_attached();
704
705 // wait for a key press if PauseAtExit is set
706 static void wait_for_keypress_at_exit(void);
707
708 // The following two functions are used by fatal error handler to trace
709 // native (C) frames. They are not part of frame.hpp/frame.cpp because
710 // frame.hpp/cpp assume thread is JavaThread, and also because different
711 // OS/compiler may have different convention or provide different API to
712 // walk C frames.
713 //
714 // We don't attempt to become a debugger, so we only follow frames if that
715 // does not require a lookup in the unwind table, which is part of the binary
716 // file but may be unsafe to read after a fatal error. So on x86, we can
717 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
718 // possible to walk C stack without having the unwind table.
719 static bool is_first_C_frame(frame *fr);
720 static frame get_sender_for_C_frame(frame *fr);
721
722 // return current frame. pc() and sp() are set to NULL on failure.
723 static frame current_frame();
724
725 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
726
727 // returns a string to describe the exception/signal;
728 // returns NULL if exception_code is not an OS exception/signal.
729 static const char* exception_name(int exception_code, char* buf, size_t buflen);
730
731 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
732 static int get_signal_number(const char* signal_name);
733
734 // Returns native Java library, loads if necessary
735 static void* native_java_library();
736
737 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
738 static void jvm_path(char *buf, jint buflen);
739
740 // JNI names
741 static void print_jni_name_prefix_on(outputStream* st, int args_size);
742 static void print_jni_name_suffix_on(outputStream* st, int args_size);
743
744 // Init os specific system properties values
745 static void init_system_properties_values();
746
747 // IO operations, non-JVM_ version.
748 static int stat(const char* path, struct stat* sbuf);
749 static bool dir_is_empty(const char* path);
750
751 // IO operations on binary files
752 static int create_binary_file(const char* path, bool rewrite_existing);
753 static jlong current_file_offset(int fd);
754 static jlong seek_to_file_offset(int fd, jlong offset);
755
756 // Retrieve native stack frames.
757 // Parameter:
758 // stack: an array to storage stack pointers.
759 // frames: size of above array.
760 // toSkip: number of stack frames to skip at the beginning.
761 // Return: number of stack frames captured.
762 static int get_native_stack(address* stack, int size, int toSkip = 0);
763
764 // General allocation (must be MT-safe)
765 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
766 static void* malloc (size_t size, MEMFLAGS flags);
767 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
768 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
769
770 static void free (void *memblock);
771 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
772 // Like strdup, but exit VM when strdup() returns NULL
773 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
774
775 #ifndef PRODUCT
776 static julong num_mallocs; // # of calls to malloc/realloc
777 static julong alloc_bytes; // # of bytes allocated
778 static julong num_frees; // # of calls to free
779 static julong free_bytes; // # of bytes freed
780 #endif
781
782 // SocketInterface (ex HPI SocketInterface )
783 static int socket(int domain, int type, int protocol);
784 static int socket_close(int fd);
785 static int recv(int fd, char* buf, size_t nBytes, uint flags);
786 static int send(int fd, char* buf, size_t nBytes, uint flags);
787 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
788 static int connect(int fd, struct sockaddr* him, socklen_t len);
789 static struct hostent* get_host_by_name(char* name);
790
791 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
792 static void initialize_jdk_signal_support(TRAPS);
793 static void signal_notify(int signal_number);
794 static void* signal(int signal_number, void* handler);
795 static void signal_raise(int signal_number);
796 static int signal_wait();
797 static void* user_handler();
798 static void terminate_signal_thread();
799 static int sigexitnum_pd();
800
801 // random number generation
802 static int random(); // return 32bit pseudorandom number
803 static void init_random(unsigned int initval); // initialize random sequence
804
805 // Structured OS Exception support
806 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
807
808 // On Posix compatible OS it will simply check core dump limits while on Windows
809 // it will check if dump file can be created. Check or prepare a core dump to be
810 // taken at a later point in the same thread in os::abort(). Use the caller
811 // provided buffer as a scratch buffer. The status message which will be written
812 // into the error log either is file location or a short error message, depending
813 // on the checking result.
814 static void check_dump_limit(char* buffer, size_t bufferSize);
815
816 // Get the default path to the core file
817 // Returns the length of the string
818 static int get_core_path(char* buffer, size_t bufferSize);
819
820 // JVMTI & JVM monitoring and management support
821 // The thread_cpu_time() and current_thread_cpu_time() are only
822 // supported if is_thread_cpu_time_supported() returns true.
823 // They are not supported on Solaris T1.
824
825 // Thread CPU Time - return the fast estimate on a platform
826 // On Solaris - call gethrvtime (fast) - user time only
827 // On Linux - fast clock_gettime where available - user+sys
828 // - otherwise: very slow /proc fs - user+sys
829 // On Windows - GetThreadTimes - user+sys
830 static jlong current_thread_cpu_time();
831 static jlong thread_cpu_time(Thread* t);
832
833 // Thread CPU Time with user_sys_cpu_time parameter.
834 //
835 // If user_sys_cpu_time is true, user+sys time is returned.
836 // Otherwise, only user time is returned
837 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
838 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
839
840 // Return a bunch of info about the timers.
841 // Note that the returned info for these two functions may be different
842 // on some platforms
843 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
844 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
845
846 static bool is_thread_cpu_time_supported();
847
848 // System loadavg support. Returns -1 if load average cannot be obtained.
849 static int loadavg(double loadavg[], int nelem);
850
851 // Hook for os specific jvm options that we don't want to abort on seeing
852 static bool obsolete_option(const JavaVMOption *option);
853
854 // Amount beyond the callee frame size that we bang the stack.
855 static int extra_bang_size_in_bytes();
856
857 static char** split_path(const char* path, int* n);
858
859 // Extensions
860 #include "runtime/os_ext.hpp"
861
862 public:
863 class CrashProtectionCallback : public StackObj {
864 public:
865 virtual void call() = 0;
866 };
867
868 // Platform dependent stuff
869 #ifndef _WINDOWS
870 # include "os_posix.hpp"
871 #endif
872 #include OS_CPU_HEADER(os)
873 #include OS_HEADER(os)
874
875 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
876 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
877 #endif
878
879 public:
880 #ifndef PLATFORM_PRINT_NATIVE_STACK
881 // No platform-specific code for printing the native stack.
882 static bool platform_print_native_stack(outputStream* st, const void* context,
883 char *buf, int buf_size) {
884 return false;
885 }
886 #endif
887
888 // debugging support (mostly used by debug.cpp but also fatal error handler)
889 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
890
891 static bool dont_yield(); // when true, JVM_Yield() is nop
892 static void print_statistics();
893
894 // Thread priority helpers (implemented in OS-specific part)
895 static OSReturn set_native_priority(Thread* thread, int native_prio);
896 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
897 static int java_to_os_priority[CriticalPriority + 1];
898 // Hint to the underlying OS that a task switch would not be good.
899 // Void return because it's a hint and can fail.
900 static void hint_no_preempt();
901 static const char* native_thread_creation_failed_msg() {
902 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
903 }
904
905 // Used at creation if requested by the diagnostic flag PauseAtStartup.
906 // Causes the VM to wait until an external stimulus has been applied
907 // (for Unix, that stimulus is a signal, for Windows, an external
908 // ResumeThread call)
909 static void pause();
910
911 // Builds a platform dependent Agent_OnLoad_<libname> function name
912 // which is used to find statically linked in agents.
913 static char* build_agent_function_name(const char *sym, const char *cname,
914 bool is_absolute_path);
915
916 class SuspendedThreadTaskContext {
917 public:
918 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
919 Thread* thread() const { return _thread; }
920 void* ucontext() const { return _ucontext; }
921 private:
922 Thread* _thread;
923 void* _ucontext;
924 };
925
926 class SuspendedThreadTask {
927 public:
928 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
929 void run();
930 bool is_done() { return _done; }
931 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
932 protected:
933 ~SuspendedThreadTask() {}
934 private:
935 void internal_do_task();
936 Thread* _thread;
937 bool _done;
938 };
939
940 #ifndef _WINDOWS
941 // Suspend/resume support
942 // Protocol:
943 //
944 // a thread starts in SR_RUNNING
945 //
946 // SR_RUNNING can go to
947 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
948 // SR_SUSPEND_REQUEST can go to
949 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
950 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
951 // SR_SUSPENDED can go to
952 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
953 // SR_WAKEUP_REQUEST can go to
954 // * SR_RUNNING when the stopped thread receives the signal
955 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
956 class SuspendResume {
957 public:
958 enum State {
959 SR_RUNNING,
960 SR_SUSPEND_REQUEST,
961 SR_SUSPENDED,
962 SR_WAKEUP_REQUEST
963 };
964
965 private:
966 volatile State _state;
967
968 private:
969 /* try to switch state from state "from" to state "to"
970 * returns the state set after the method is complete
971 */
972 State switch_state(State from, State to);
973
974 public:
975 SuspendResume() : _state(SR_RUNNING) { }
976
977 State state() const { return _state; }
978
979 State request_suspend() {
980 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
981 }
982
983 State cancel_suspend() {
984 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
985 }
986
987 State suspended() {
988 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
989 }
990
991 State request_wakeup() {
992 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
993 }
994
995 State running() {
996 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
997 }
998
999 bool is_running() const {
1000 return _state == SR_RUNNING;
1001 }
1002
1003 bool is_suspend_request() const {
1004 return _state == SR_SUSPEND_REQUEST;
1005 }
1006
1007 bool is_suspended() const {
1008 return _state == SR_SUSPENDED;
1009 }
1010 };
1011 #endif // !WINDOWS
1012
1013
1014 protected:
1015 static volatile unsigned int _rand_seed; // seed for random number generator
1016 static int _processor_count; // number of processors
1017 static int _initial_active_processor_count; // number of active processors during initialization.
1018
1019 static char* format_boot_path(const char* format_string,
1020 const char* home,
1021 int home_len,
1022 char fileSep,
1023 char pathSep);
1024 static bool set_boot_path(char fileSep, char pathSep);
1025
1026 };
1027
1028 #ifndef _WINDOWS
1029 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {};
1030 #endif // !_WINDOWS
1031
1032 // Note that "PAUSE" is almost always used with synchronization
1033 // so arguably we should provide Atomic::SpinPause() instead
1034 // of the global SpinPause() with C linkage.
1035 // It'd also be eligible for inlining on many platforms.
1036
1037 #if defined(X86) && !defined(_WINDOWS)
1038 extern "C" int inline SpinPause() {
1039 __asm__ __volatile__ ("pause");
1040 return 1;
1041 }
1042 #else
1043 extern "C" int SpinPause();
1044 #endif
1045
1046 #endif // SHARE_VM_RUNTIME_OS_HPP