1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_OS_HPP
26 #define SHARE_VM_RUNTIME_OS_HPP
27
28 #include "jvmtifiles/jvmti.h"
29 #include "runtime/extendedPC.hpp"
30 #include "runtime/handles.hpp"
31 #include "utilities/top.hpp"
32 #ifdef TARGET_OS_FAMILY_linux
33 # include "jvm_linux.h"
34 # include <setjmp.h>
35 #endif
36 #ifdef TARGET_OS_FAMILY_solaris
37 # include "jvm_solaris.h"
38 # include <setjmp.h>
39 #endif
40 #ifdef TARGET_OS_FAMILY_windows
41 # include "jvm_windows.h"
42 #endif
43 #ifdef TARGET_OS_FAMILY_aix
44 # include "jvm_aix.h"
45 # include <setjmp.h>
46 #endif
47 #ifdef TARGET_OS_FAMILY_bsd
48 # include "jvm_bsd.h"
49 # include <setjmp.h>
50 # ifdef __APPLE__
51 # include <mach/mach_time.h>
52 # endif
53 #endif
54
55 class AgentLibrary;
56
57 // os defines the interface to operating system; this includes traditional
58 // OS services (time, I/O) as well as other functionality with system-
59 // dependent code.
60
61 typedef void (*dll_func)(...);
62
63 class Thread;
64 class JavaThread;
65 class Event;
66 class DLL;
67 class FileHandle;
68 class NativeCallStack;
69
70 template<class E> class GrowableArray;
71
72 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
73
74 // Platform-independent error return values from OS functions
75 enum OSReturn {
76 OS_OK = 0, // Operation was successful
77 OS_ERR = -1, // Operation failed
78 OS_INTRPT = -2, // Operation was interrupted
79 OS_TIMEOUT = -3, // Operation timed out
80 OS_NOMEM = -5, // Operation failed for lack of memory
81 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
82 };
83
84 enum ThreadPriority { // JLS 20.20.1-3
85 NoPriority = -1, // Initial non-priority value
86 MinPriority = 1, // Minimum priority
87 NormPriority = 5, // Normal (non-daemon) priority
88 NearMaxPriority = 9, // High priority, used for VMThread
89 MaxPriority = 10, // Highest priority, used for WatcherThread
90 // ensures that VMThread doesn't starve profiler
91 CriticalPriority = 11 // Critical thread priority
92 };
93
94 // Executable parameter flag for os::commit_memory() and
95 // os::commit_memory_or_exit().
96 const bool ExecMem = true;
97
98 // Typedef for structured exception handling support
99 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
100
101 class MallocTracker;
102
103 class os: AllStatic {
104 friend class VMStructs;
105 friend class JVMCIVMStructs;
106 friend class MallocTracker;
107 public:
108 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
109
110 private:
111 static OSThread* _starting_thread;
112 static address _polling_page;
113 static volatile int32_t * _mem_serialize_page;
114 static uintptr_t _serialize_page_mask;
115 public:
116 static size_t _page_sizes[page_sizes_max];
117
118 private:
119 static void init_page_sizes(size_t default_page_size) {
120 _page_sizes[0] = default_page_size;
121 _page_sizes[1] = 0; // sentinel
122 }
123
124 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
125 size_t alignment_hint = 0);
126 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
127 static void pd_split_reserved_memory(char *base, size_t size,
128 size_t split, bool realloc);
129 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
130 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
131 bool executable);
132 // Same as pd_commit_memory() that either succeeds or calls
133 // vm_exit_out_of_memory() with the specified mesg.
134 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
135 bool executable, const char* mesg);
136 static void pd_commit_memory_or_exit(char* addr, size_t size,
137 size_t alignment_hint,
138 bool executable, const char* mesg);
139 static bool pd_uncommit_memory(char* addr, size_t bytes);
140 static bool pd_release_memory(char* addr, size_t bytes);
141
142 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
143 char *addr, size_t bytes, bool read_only = false,
144 bool allow_exec = false);
145 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
146 char *addr, size_t bytes, bool read_only,
147 bool allow_exec);
148 static bool pd_unmap_memory(char *addr, size_t bytes);
149 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
150 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
151
152 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
153
154 // Get summary strings for system information in buffer provided
155 static void get_summary_cpu_info(char* buf, size_t buflen);
156 static void get_summary_os_info(char* buf, size_t buflen);
157
158 public:
159 static void init(void); // Called before command line parsing
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 // Fill in buffer with current local time as an ISO-8601 string.
215 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
216 // Returns buffer, or NULL if it failed.
217 static char* iso8601_time(char* buffer, size_t buffer_length);
218
219 // Interface for detecting multiprocessor system
220 static inline bool is_MP() {
221 // During bootstrap if _processor_count is not yet initialized
222 // we claim to be MP as that is safest. If any platform has a
223 // stub generator that might be triggered in this phase and for
224 // which being declared MP when in fact not, is a problem - then
225 // the bootstrap routine for the stub generator needs to check
226 // the processor count directly and leave the bootstrap routine
227 // in place until called after initialization has ocurred.
228 return (_processor_count != 1) || AssumeMP;
229 }
230 static julong available_memory();
231 static julong physical_memory();
232 static bool has_allocatable_memory_limit(julong* limit);
233 static bool is_server_class_machine();
234
235 // number of CPUs
236 static int processor_count() {
237 return _processor_count;
238 }
239 static void set_processor_count(int count) { _processor_count = count; }
240
241 // Returns the number of CPUs this process is currently allowed to run on.
242 // Note that on some OSes this can change dynamically.
243 static int active_processor_count();
244
245 // Bind processes to processors.
246 // This is a two step procedure:
247 // first you generate a distribution of processes to processors,
248 // then you bind processes according to that distribution.
249 // Compute a distribution for number of processes to processors.
250 // Stores the processor id's into the distribution array argument.
251 // Returns true if it worked, false if it didn't.
252 static bool distribute_processes(uint length, uint* distribution);
253 // Binds the current process to a processor.
254 // Returns true if it worked, false if it didn't.
255 static bool bind_to_processor(uint processor_id);
256
257 // Give a name to the current thread.
258 static void set_native_thread_name(const char *name);
259
260 // Interface for stack banging (predetect possible stack overflow for
261 // exception processing) There are guard pages, and above that shadow
262 // pages for stack overflow checking.
263 static bool uses_stack_guard_pages();
264 static bool allocate_stack_guard_pages();
265 static void map_stack_shadow_pages();
266 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method);
267
268 // OS interface to Virtual Memory
269
270 // Return the default page size.
271 static int vm_page_size();
272
273 // Returns the page size to use for a region of memory.
274 // region_size / min_pages will always be greater than or equal to the
275 // returned value. The returned value will divide region_size.
276 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
277
278 // Returns the page size to use for a region of memory.
279 // region_size / min_pages will always be greater than or equal to the
280 // returned value. The returned value might not divide region_size.
281 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
282
283 // Return the largest page size that can be used
284 static size_t max_page_size() {
285 // The _page_sizes array is sorted in descending order.
286 return _page_sizes[0];
287 }
288
289 // Methods for tracing page sizes returned by the above method; enabled by
290 // TracePageSizes. The region_{min,max}_size parameters should be the values
291 // passed to page_size_for_region() and page_size should be the result of that
292 // call. The (optional) base and size parameters should come from the
293 // ReservedSpace base() and size() methods.
294 static void trace_page_sizes(const char* str, const size_t* page_sizes,
295 int count) PRODUCT_RETURN;
296 static void trace_page_sizes(const char* str, const size_t region_min_size,
297 const size_t region_max_size,
298 const size_t page_size,
299 const char* base = NULL,
300 const size_t size = 0) PRODUCT_RETURN;
301
302 static int vm_allocation_granularity();
303 static char* reserve_memory(size_t bytes, char* addr = 0,
304 size_t alignment_hint = 0);
305 static char* reserve_memory(size_t bytes, char* addr,
306 size_t alignment_hint, MEMFLAGS flags);
307 static char* reserve_memory_aligned(size_t size, size_t alignment);
308 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
309 static void split_reserved_memory(char *base, size_t size,
310 size_t split, bool realloc);
311 static bool commit_memory(char* addr, size_t bytes, bool executable);
312 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
313 bool executable);
314 // Same as commit_memory() that either succeeds or calls
315 // vm_exit_out_of_memory() with the specified mesg.
316 static void commit_memory_or_exit(char* addr, size_t bytes,
317 bool executable, const char* mesg);
318 static void commit_memory_or_exit(char* addr, size_t size,
319 size_t alignment_hint,
320 bool executable, const char* mesg);
321 static bool uncommit_memory(char* addr, size_t bytes);
322 static bool release_memory(char* addr, size_t bytes);
323
324 // Touch memory pages that cover the memory range from start to end (exclusive)
325 // to make the OS back the memory range with actual memory.
326 // Current implementation may not touch the last page if unaligned addresses
327 // are passed.
328 static void pretouch_memory(void* start, void* end);
329
330 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
331 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
332 bool is_committed = true);
333
334 static bool guard_memory(char* addr, size_t bytes);
335 static bool unguard_memory(char* addr, size_t bytes);
336 static bool create_stack_guard_pages(char* addr, size_t bytes);
337 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
338 static bool remove_stack_guard_pages(char* addr, size_t bytes);
339
340 static char* map_memory(int fd, const char* file_name, size_t file_offset,
341 char *addr, size_t bytes, bool read_only = false,
342 bool allow_exec = false);
343 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
344 char *addr, size_t bytes, bool read_only,
345 bool allow_exec);
346 static bool unmap_memory(char *addr, size_t bytes);
347 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
348 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
349
350 // NUMA-specific interface
351 static bool numa_has_static_binding();
352 static bool numa_has_group_homing();
353 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
354 static void numa_make_global(char *addr, size_t bytes);
355 static size_t numa_get_groups_num();
356 static size_t numa_get_leaf_groups(int *ids, size_t size);
357 static bool numa_topology_changed();
358 static int numa_get_group_id();
359
360 // Page manipulation
361 struct page_info {
362 size_t size;
363 int lgrp_id;
364 };
365 static bool get_page_info(char *start, page_info* info);
366 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
367
368 static char* non_memory_address_word();
369 // reserve, commit and pin the entire memory region
370 static char* reserve_memory_special(size_t size, size_t alignment,
371 char* addr, bool executable);
372 static bool release_memory_special(char* addr, size_t bytes);
373 static void large_page_init();
374 static size_t large_page_size();
375 static bool can_commit_large_page_memory();
376 static bool can_execute_large_page_memory();
377
378 // OS interface to polling page
379 static address get_polling_page() { return _polling_page; }
380 static void set_polling_page(address page) { _polling_page = page; }
381 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
382 static void make_polling_page_unreadable();
383 static void make_polling_page_readable();
384
385 // Routines used to serialize the thread state without using membars
386 static void serialize_thread_states();
387
388 // Since we write to the serialize page from every thread, we
389 // want stores to be on unique cache lines whenever possible
390 // in order to minimize CPU cross talk. We pre-compute the
391 // amount to shift the thread* to make this offset unique to
392 // each thread.
393 static int get_serialize_page_shift_count() {
394 return SerializePageShiftCount;
395 }
396
397 static void set_serialize_page_mask(uintptr_t mask) {
398 _serialize_page_mask = mask;
399 }
400
401 static unsigned int get_serialize_page_mask() {
402 return _serialize_page_mask;
403 }
404
405 static void set_memory_serialize_page(address page);
406
407 static address get_memory_serialize_page() {
408 return (address)_mem_serialize_page;
409 }
410
411 static inline void write_memory_serialize_page(JavaThread *thread) {
412 uintptr_t page_offset = ((uintptr_t)thread >>
413 get_serialize_page_shift_count()) &
414 get_serialize_page_mask();
415 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
416 }
417
418 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
419 if (UseMembar) return false;
420 // Previously this function calculated the exact address of this
421 // thread's serialize page, and checked if the faulting address
422 // was equal. However, some platforms mask off faulting addresses
423 // to the page size, so now we just check that the address is
424 // within the page. This makes the thread argument unnecessary,
425 // but we retain the NULL check to preserve existing behavior.
426 if (thread == NULL) return false;
427 address page = (address) _mem_serialize_page;
428 return addr >= page && addr < (page + os::vm_page_size());
429 }
430
431 static void block_on_serialize_page_trap();
432
433 // threads
434
435 enum ThreadType {
436 vm_thread,
437 cgc_thread, // Concurrent GC thread
438 pgc_thread, // Parallel GC thread
439 java_thread,
440 compiler_thread,
441 watcher_thread,
442 os_thread
443 };
444
445 static bool create_thread(Thread* thread,
446 ThreadType thr_type,
447 size_t stack_size = 0);
448 static bool create_main_thread(JavaThread* thread);
449 static bool create_attached_thread(JavaThread* thread);
450 static void pd_start_thread(Thread* thread);
451 static void start_thread(Thread* thread);
452
453 static void initialize_thread(Thread* thr);
454 static void free_thread(OSThread* osthread);
455
456 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
457 static intx current_thread_id();
458 static int current_process_id();
459 static int sleep(Thread* thread, jlong ms, bool interruptable);
460 // Short standalone OS sleep suitable for slow path spin loop.
461 // Ignores Thread.interrupt() (so keep it short).
462 // ms = 0, will sleep for the least amount of time allowed by the OS.
463 static void naked_short_sleep(jlong ms);
464 static void infinite_sleep(); // never returns, use with CAUTION
465 static void naked_yield () ;
466 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
467 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
468
469 static void interrupt(Thread* thread);
470 static bool is_interrupted(Thread* thread, bool clear_interrupted);
471
472 static int pd_self_suspend_thread(Thread* thread);
473
474 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
475 static frame fetch_frame_from_context(const void* ucVoid);
476 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
477
478 static ExtendedPC get_thread_pc(Thread *thread);
479 static void breakpoint();
480 static bool start_debugging(char *buf, int buflen);
481
482 static address current_stack_pointer();
483 static address current_stack_base();
484 static size_t current_stack_size();
485
486 static void verify_stack_alignment() PRODUCT_RETURN;
487
488 static bool message_box(const char* title, const char* message);
489 static char* do_you_want_to_debug(const char* message);
490
491 // run cmd in a separate process and return its exit code; or -1 on failures
492 static int fork_and_exec(char *cmd);
493
494 // Call ::exit() on all platforms but Windows
495 static void exit(int num);
496
497 // Terminate the VM, but don't exit the process
498 static void shutdown();
499
500 // Terminate with an error. Default is to generate a core file on platforms
501 // that support such things. This calls shutdown() and then aborts.
502 static void abort(bool dump_core, void *siginfo, const void *context);
503 static void abort(bool dump_core = true);
504
505 // Die immediately, no exit hook, no abort hook, no cleanup.
506 static void die();
507
508 // File i/o operations
509 static const int default_file_open_flags();
510 static int open(const char *path, int oflag, int mode);
511 static FILE* open(int fd, const char* mode);
512 static int close(int fd);
513 static jlong lseek(int fd, jlong offset, int whence);
514 static char* native_path(char *path);
515 static int ftruncate(int fd, jlong length);
516 static int fsync(int fd);
517 static int available(int fd, jlong *bytes);
518 static void flockfile(FILE* fp);
519 static void funlockfile(FILE* fp);
520
521 //File i/o operations
522
523 static size_t read(int fd, void *buf, unsigned int nBytes);
524 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
525 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
526 static size_t write(int fd, const void *buf, unsigned int nBytes);
527
528 // Reading directories.
529 static DIR* opendir(const char* dirname);
530 static int readdir_buf_size(const char *path);
531 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
532 static int closedir(DIR* dirp);
533
534 // Dynamic library extension
535 static const char* dll_file_extension();
536
537 static const char* get_temp_directory();
538 static const char* get_current_directory(char *buf, size_t buflen);
539
540 // Builds a platform-specific full library path given a ld path and lib name
541 // Returns true if buffer contains full path to existing file, false otherwise
542 static bool dll_build_name(char* buffer, size_t size,
543 const char* pathname, const char* fname);
544
545 // Symbol lookup, find nearest function name; basically it implements
546 // dladdr() for all platforms. Name of the nearest function is copied
547 // to buf. Distance from its base address is optionally returned as offset.
548 // If function name is not found, buf[0] is set to '\0' and offset is
549 // set to -1 (if offset is non-NULL).
550 static bool dll_address_to_function_name(address addr, char* buf,
551 int buflen, int* offset,
552 bool demangle = true);
553
554 // Locate DLL/DSO. On success, full path of the library is copied to
555 // buf, and offset is optionally set to be the distance between addr
556 // and the library's base address. On failure, buf[0] is set to '\0'
557 // and offset is set to -1 (if offset is non-NULL).
558 static bool dll_address_to_library_name(address addr, char* buf,
559 int buflen, int* offset);
560
561 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
562 static bool address_is_in_vm(address addr);
563
564 // Loads .dll/.so and
565 // in case of error it checks if .dll/.so was built for the
566 // same architecture as HotSpot is running on
567 static void* dll_load(const char *name, char *ebuf, int ebuflen);
568
569 // lookup symbol in a shared library
570 static void* dll_lookup(void* handle, const char* name);
571
572 // Unload library
573 static void dll_unload(void *lib);
574
575 // Callback for loaded module information
576 // Input parameters:
577 // char* module_file_name,
578 // address module_base_addr,
579 // address module_top_addr,
580 // void* param
581 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
582
583 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
584
585 // Return the handle of this process
586 static void* get_default_process_handle();
587
588 // Check for static linked agent library
589 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
590 size_t syms_len);
591
592 // Find agent entry point
593 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
594 const char *syms[], size_t syms_len);
595
596 // Write to stream
597 static int log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
598
599 // Get host name in buffer provided
600 static bool get_host_name(char* buf, size_t buflen);
601
602 // Print out system information; they are called by fatal error handler.
603 // Output format may be different on different platforms.
604 static void print_os_info(outputStream* st);
605 static void print_os_info_brief(outputStream* st);
606 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
607 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
608 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
609 static void print_memory_info(outputStream* st);
610 static void print_dll_info(outputStream* st);
611 static void print_environment_variables(outputStream* st, const char** env_list);
612 static void print_context(outputStream* st, const void* context);
613 static void print_register_info(outputStream* st, const void* context);
614 static void print_siginfo(outputStream* st, const void* siginfo);
615 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
616 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
617
618 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
619 static size_t lasterror(char *buf, size_t len);
620 static int get_last_error();
621
622 // Replacement for strerror().
623 // Will return the english description of the error (e.g. "File not found", as
624 // suggested in the POSIX standard.
625 // Will return "Unknown error" for an unknown errno value.
626 // Will not attempt to localize the returned string.
627 // Will always return a valid string which is a static constant.
628 // Will not change the value of errno.
629 static const char* strerror(int e);
630
631 // Will return the literalized version of the given errno (e.g. "EINVAL"
632 // for EINVAL).
633 // Will return "Unknown error" for an unknown errno value.
634 // Will always return a valid string which is a static constant.
635 // Will not change the value of errno.
636 static const char* errno_name(int e);
637
638 // Determines whether the calling process is being debugged by a user-mode debugger.
639 static bool is_debugger_attached();
640
641 // wait for a key press if PauseAtExit is set
642 static void wait_for_keypress_at_exit(void);
643
644 // The following two functions are used by fatal error handler to trace
645 // native (C) frames. They are not part of frame.hpp/frame.cpp because
646 // frame.hpp/cpp assume thread is JavaThread, and also because different
647 // OS/compiler may have different convention or provide different API to
648 // walk C frames.
649 //
650 // We don't attempt to become a debugger, so we only follow frames if that
651 // does not require a lookup in the unwind table, which is part of the binary
652 // file but may be unsafe to read after a fatal error. So on x86, we can
653 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
654 // possible to walk C stack without having the unwind table.
655 static bool is_first_C_frame(frame *fr);
656 static frame get_sender_for_C_frame(frame *fr);
657
658 // return current frame. pc() and sp() are set to NULL on failure.
659 static frame current_frame();
660
661 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
662
663 // returns a string to describe the exception/signal;
664 // returns NULL if exception_code is not an OS exception/signal.
665 static const char* exception_name(int exception_code, char* buf, size_t buflen);
666
667 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
668 static int get_signal_number(const char* signal_name);
669
670 // Returns native Java library, loads if necessary
671 static void* native_java_library();
672
673 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
674 static void jvm_path(char *buf, jint buflen);
675
676 // Returns true if we are running in a headless jre.
677 static bool is_headless_jre();
678
679 // JNI names
680 static void print_jni_name_prefix_on(outputStream* st, int args_size);
681 static void print_jni_name_suffix_on(outputStream* st, int args_size);
682
683 // Init os specific system properties values
684 static void init_system_properties_values();
685
686 // IO operations, non-JVM_ version.
687 static int stat(const char* path, struct stat* sbuf);
688 static bool dir_is_empty(const char* path);
689
690 // IO operations on binary files
691 static int create_binary_file(const char* path, bool rewrite_existing);
692 static jlong current_file_offset(int fd);
693 static jlong seek_to_file_offset(int fd, jlong offset);
694
695 // Retrieve native stack frames.
696 // Parameter:
697 // stack: an array to storage stack pointers.
698 // frames: size of above array.
699 // toSkip: number of stack frames to skip at the beginning.
700 // Return: number of stack frames captured.
701 static int get_native_stack(address* stack, int size, int toSkip = 0);
702
703 // General allocation (must be MT-safe)
704 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
705 static void* malloc (size_t size, MEMFLAGS flags);
706 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
707 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
708
709 static void free (void *memblock);
710 static bool check_heap(bool force = false); // verify C heap integrity
711 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
712 // Like strdup, but exit VM when strdup() returns NULL
713 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
714
715 #ifndef PRODUCT
716 static julong num_mallocs; // # of calls to malloc/realloc
717 static julong alloc_bytes; // # of bytes allocated
718 static julong num_frees; // # of calls to free
719 static julong free_bytes; // # of bytes freed
720 #endif
721
722 // SocketInterface (ex HPI SocketInterface )
723 static int socket(int domain, int type, int protocol);
724 static int socket_close(int fd);
725 static int recv(int fd, char* buf, size_t nBytes, uint flags);
726 static int send(int fd, char* buf, size_t nBytes, uint flags);
727 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
728 static int connect(int fd, struct sockaddr* him, socklen_t len);
729 static struct hostent* get_host_by_name(char* name);
730
731 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
732 static void signal_init();
733 static void signal_init_pd();
734 static void signal_notify(int signal_number);
735 static void* signal(int signal_number, void* handler);
736 static void signal_raise(int signal_number);
737 static int signal_wait();
738 static int signal_lookup();
739 static void* user_handler();
740 static void terminate_signal_thread();
741 static int sigexitnum_pd();
742
743 // random number generation
744 static long random(); // return 32bit pseudorandom number
745 static void init_random(long initval); // initialize random sequence
746
747 // Structured OS Exception support
748 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
749
750 // On Posix compatible OS it will simply check core dump limits while on Windows
751 // it will check if dump file can be created. Check or prepare a core dump to be
752 // taken at a later point in the same thread in os::abort(). Use the caller
753 // provided buffer as a scratch buffer. The status message which will be written
754 // into the error log either is file location or a short error message, depending
755 // on the checking result.
756 static void check_dump_limit(char* buffer, size_t bufferSize);
757
758 // Get the default path to the core file
759 // Returns the length of the string
760 static int get_core_path(char* buffer, size_t bufferSize);
761
762 // JVMTI & JVM monitoring and management support
763 // The thread_cpu_time() and current_thread_cpu_time() are only
764 // supported if is_thread_cpu_time_supported() returns true.
765 // They are not supported on Solaris T1.
766
767 // Thread CPU Time - return the fast estimate on a platform
768 // On Solaris - call gethrvtime (fast) - user time only
769 // On Linux - fast clock_gettime where available - user+sys
770 // - otherwise: very slow /proc fs - user+sys
771 // On Windows - GetThreadTimes - user+sys
772 static jlong current_thread_cpu_time();
773 static jlong thread_cpu_time(Thread* t);
774
775 // Thread CPU Time with user_sys_cpu_time parameter.
776 //
777 // If user_sys_cpu_time is true, user+sys time is returned.
778 // Otherwise, only user time is returned
779 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
780 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
781
782 // Return a bunch of info about the timers.
783 // Note that the returned info for these two functions may be different
784 // on some platforms
785 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
786 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
787
788 static bool is_thread_cpu_time_supported();
789
790 // System loadavg support. Returns -1 if load average cannot be obtained.
791 static int loadavg(double loadavg[], int nelem);
792
793 // Hook for os specific jvm options that we don't want to abort on seeing
794 static bool obsolete_option(const JavaVMOption *option);
795
796 // Amount beyond the callee frame size that we bang the stack.
797 static int extra_bang_size_in_bytes();
798
799 static char** split_path(const char* path, int* n);
800
801 // Extensions
802 #include "runtime/os_ext.hpp"
803
804 public:
805 class CrashProtectionCallback : public StackObj {
806 public:
807 virtual void call() = 0;
808 };
809
810 // Platform dependent stuff
811 #ifdef TARGET_OS_FAMILY_linux
812 # include "os_linux.hpp"
813 # include "os_posix.hpp"
814 #endif
815 #ifdef TARGET_OS_FAMILY_solaris
816 # include "os_solaris.hpp"
817 # include "os_posix.hpp"
818 #endif
819 #ifdef TARGET_OS_FAMILY_windows
820 # include "os_windows.hpp"
821 #endif
822 #ifdef TARGET_OS_FAMILY_aix
823 # include "os_aix.hpp"
824 # include "os_posix.hpp"
825 #endif
826 #ifdef TARGET_OS_FAMILY_bsd
827 # include "os_posix.hpp"
828 # include "os_bsd.hpp"
829 #endif
830 #ifdef TARGET_OS_ARCH_linux_x86
831 # include "os_linux_x86.hpp"
832 #endif
833 #ifdef TARGET_OS_ARCH_linux_sparc
834 # include "os_linux_sparc.hpp"
835 #endif
836 #ifdef TARGET_OS_ARCH_linux_zero
837 # include "os_linux_zero.hpp"
838 #endif
839 #ifdef TARGET_OS_ARCH_solaris_x86
840 # include "os_solaris_x86.hpp"
841 #endif
842 #ifdef TARGET_OS_ARCH_solaris_sparc
843 # include "os_solaris_sparc.hpp"
844 #endif
845 #ifdef TARGET_OS_ARCH_windows_x86
846 # include "os_windows_x86.hpp"
847 #endif
848 #ifdef TARGET_OS_ARCH_linux_arm
849 # include "os_linux_arm.hpp"
850 #endif
851 #ifdef TARGET_OS_ARCH_linux_ppc
852 # include "os_linux_ppc.hpp"
853 #endif
854 #ifdef TARGET_OS_ARCH_aix_ppc
855 # include "os_aix_ppc.hpp"
856 #endif
857 #ifdef TARGET_OS_ARCH_linux_aarch64
858 # include "os_linux_aarch64.hpp"
859 #endif
860 #ifdef TARGET_OS_ARCH_bsd_x86
861 # include "os_bsd_x86.hpp"
862 #endif
863 #ifdef TARGET_OS_ARCH_bsd_zero
864 # include "os_bsd_zero.hpp"
865 #endif
866
867 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
868 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
869 #endif
870
871 public:
872 #ifndef PLATFORM_PRINT_NATIVE_STACK
873 // No platform-specific code for printing the native stack.
874 static bool platform_print_native_stack(outputStream* st, const void* context,
875 char *buf, int buf_size) {
876 return false;
877 }
878 #endif
879
880 // debugging support (mostly used by debug.cpp but also fatal error handler)
881 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
882
883 static bool dont_yield(); // when true, JVM_Yield() is nop
884 static void print_statistics();
885
886 // Thread priority helpers (implemented in OS-specific part)
887 static OSReturn set_native_priority(Thread* thread, int native_prio);
888 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
889 static int java_to_os_priority[CriticalPriority + 1];
890 // Hint to the underlying OS that a task switch would not be good.
891 // Void return because it's a hint and can fail.
892 static void hint_no_preempt();
893 static const char* native_thread_creation_failed_msg() {
894 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
895 }
896
897 // Used at creation if requested by the diagnostic flag PauseAtStartup.
898 // Causes the VM to wait until an external stimulus has been applied
899 // (for Unix, that stimulus is a signal, for Windows, an external
900 // ResumeThread call)
901 static void pause();
902
903 // Builds a platform dependent Agent_OnLoad_<libname> function name
904 // which is used to find statically linked in agents.
905 static char* build_agent_function_name(const char *sym, const char *cname,
906 bool is_absolute_path);
907
908 class SuspendedThreadTaskContext {
909 public:
910 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
911 Thread* thread() const { return _thread; }
912 void* ucontext() const { return _ucontext; }
913 private:
914 Thread* _thread;
915 void* _ucontext;
916 };
917
918 class SuspendedThreadTask {
919 public:
920 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
921 virtual ~SuspendedThreadTask() {}
922 void run();
923 bool is_done() { return _done; }
924 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
925 protected:
926 private:
927 void internal_do_task();
928 Thread* _thread;
929 bool _done;
930 };
931
932 #ifndef TARGET_OS_FAMILY_windows
933 // Suspend/resume support
934 // Protocol:
935 //
936 // a thread starts in SR_RUNNING
937 //
938 // SR_RUNNING can go to
939 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
940 // SR_SUSPEND_REQUEST can go to
941 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
942 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
943 // SR_SUSPENDED can go to
944 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
945 // SR_WAKEUP_REQUEST can go to
946 // * SR_RUNNING when the stopped thread receives the signal
947 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
948 class SuspendResume {
949 public:
950 enum State {
951 SR_RUNNING,
952 SR_SUSPEND_REQUEST,
953 SR_SUSPENDED,
954 SR_WAKEUP_REQUEST
955 };
956
957 private:
958 volatile State _state;
959
960 private:
961 /* try to switch state from state "from" to state "to"
962 * returns the state set after the method is complete
963 */
964 State switch_state(State from, State to);
965
966 public:
967 SuspendResume() : _state(SR_RUNNING) { }
968
969 State state() const { return _state; }
970
971 State request_suspend() {
972 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
973 }
974
975 State cancel_suspend() {
976 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
977 }
978
979 State suspended() {
980 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
981 }
982
983 State request_wakeup() {
984 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
985 }
986
987 State running() {
988 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
989 }
990
991 bool is_running() const {
992 return _state == SR_RUNNING;
993 }
994
995 bool is_suspend_request() const {
996 return _state == SR_SUSPEND_REQUEST;
997 }
998
999 bool is_suspended() const {
1000 return _state == SR_SUSPENDED;
1001 }
1002 };
1003 #endif
1004
1005
1006 protected:
1007 static long _rand_seed; // seed for random number generator
1008 static int _processor_count; // number of processors
1009
1010 static char* format_boot_path(const char* format_string,
1011 const char* home,
1012 int home_len,
1013 char fileSep,
1014 char pathSep);
1015 static bool set_boot_path(char fileSep, char pathSep);
1016
1017 };
1018
1019 // Note that "PAUSE" is almost always used with synchronization
1020 // so arguably we should provide Atomic::SpinPause() instead
1021 // of the global SpinPause() with C linkage.
1022 // It'd also be eligible for inlining on many platforms.
1023
1024 extern "C" int SpinPause();
1025
1026 #endif // SHARE_VM_RUNTIME_OS_HPP