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