1 /*
2 * Copyright (c) 1997, 2015, 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, methodHandle* method, JavaCallArguments* args, Thread* thread);
100
101 class MallocTracker;
102
103 class os: AllStatic {
104 friend class VMStructs;
105 friend class MallocTracker;
106 public:
107 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
108
109 private:
110 static OSThread* _starting_thread;
111 static address _polling_page;
112 static volatile int32_t * _mem_serialize_page;
113 static uintptr_t _serialize_page_mask;
114 public:
115 static size_t _page_sizes[page_sizes_max];
116
117 private:
118 static void init_page_sizes(size_t default_page_size) {
119 _page_sizes[0] = default_page_size;
120 _page_sizes[1] = 0; // sentinel
121 }
122
123 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
124 size_t alignment_hint = 0);
125 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
126 static void pd_split_reserved_memory(char *base, size_t size,
127 size_t split, bool realloc);
128 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
129 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
130 bool executable);
131 // Same as pd_commit_memory() that either succeeds or calls
132 // vm_exit_out_of_memory() with the specified mesg.
133 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
134 bool executable, const char* mesg);
135 static void pd_commit_memory_or_exit(char* addr, size_t size,
136 size_t alignment_hint,
137 bool executable, const char* mesg);
138 static bool pd_uncommit_memory(char* addr, size_t bytes);
139 static bool pd_release_memory(char* addr, size_t bytes);
140
141 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
142 char *addr, size_t bytes, bool read_only = false,
143 bool allow_exec = false);
144 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
145 char *addr, size_t bytes, bool read_only,
146 bool allow_exec);
147 static bool pd_unmap_memory(char *addr, size_t bytes);
148 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
149 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
150
151 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
152
153 public:
154 static void init(void); // Called before command line parsing
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 // A strlcat like API for safe string concatenation of 2 NULL limited C strings
168 // strlcat is not guranteed to exist on all platforms, so we implement our own
169 static void strlcat(char *dst, const char *src, size_t size) {
170 register char *_dst = dst;
171 register char *_src = (char *)src;
172 register int _size = (int)size;
173
174 while ((_size-- != 0) && (*_dst != '\0')) {
175 _dst++;
176 }
177 while ((_size-- != 0) && (*_src != '\0')) {
178 *_dst = *_src;
179 _dst++; _src++;
180 }
181 *_dst = '\0';
182 }
183
184 // unset environment variable
185 static bool unsetenv(const char* name);
186
187 static bool have_special_privileges();
188
189 static jlong javaTimeMillis();
190 static jlong javaTimeNanos();
191 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
192 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
193 static void run_periodic_checks();
194 static bool supports_monotonic_clock();
195
196 // Returns the elapsed time in seconds since the vm started.
197 static double elapsedTime();
198
199 // Returns real time in seconds since an arbitrary point
200 // in the past.
201 static bool getTimesSecs(double* process_real_time,
202 double* process_user_time,
203 double* process_system_time);
204
205 // Interface to the performance counter
206 static jlong elapsed_counter();
207 static jlong elapsed_frequency();
208
209 // The "virtual time" of a thread is the amount of time a thread has
210 // actually run. The first function indicates whether the OS supports
211 // this functionality for the current thread, and if so:
212 // * the second enables vtime tracking (if that is required).
213 // * the third tells whether vtime is enabled.
214 // * the fourth returns the elapsed virtual time for the current
215 // thread.
216 static bool supports_vtime();
217 static bool enable_vtime();
218 static bool vtime_enabled();
219 static double elapsedVTime();
220
221 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
222 // It is MT safe, but not async-safe, as reading time zone
223 // information may require a lock on some platforms.
224 static char* local_time_string(char *buf, size_t buflen);
225 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
226 // Fill in buffer with current local time as an ISO-8601 string.
227 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
228 // Returns buffer, or NULL if it failed.
229 static char* iso8601_time(char* buffer, size_t buffer_length);
230
231 // Interface for detecting multiprocessor system
232 static inline bool is_MP() {
233 // During bootstrap if _processor_count is not yet initialized
234 // we claim to be MP as that is safest. If any platform has a
235 // stub generator that might be triggered in this phase and for
236 // which being declared MP when in fact not, is a problem - then
237 // the bootstrap routine for the stub generator needs to check
238 // the processor count directly and leave the bootstrap routine
239 // in place until called after initialization has ocurred.
240 return (_processor_count != 1) || AssumeMP;
241 }
242 static julong available_memory();
243 static julong physical_memory();
244 static bool has_allocatable_memory_limit(julong* limit);
245 static bool is_server_class_machine();
246
247 // number of CPUs
248 static int processor_count() {
249 return _processor_count;
250 }
251 static void set_processor_count(int count) { _processor_count = count; }
252
253 // Returns the number of CPUs this process is currently allowed to run on.
254 // Note that on some OSes this can change dynamically.
255 static int active_processor_count();
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 allocate_stack_guard_pages();
277 static void bang_stack_shadow_pages();
278 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
279
280 // OS interface to Virtual Memory
281
282 // Return the default page size.
283 static int vm_page_size();
284
285 // Returns the page size to use for a region of memory.
286 // region_size / min_pages will always be greater than or equal to the
287 // returned value. The returned value will divide region_size.
288 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
289
290 // Returns the page size to use for a region of memory.
291 // region_size / min_pages will always be greater than or equal to the
292 // returned value. The returned value might not divide region_size.
293 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
294
295 // Return the largest page size that can be used
296 static size_t max_page_size() {
297 // The _page_sizes array is sorted in descending order.
298 return _page_sizes[0];
299 }
300
301 // Methods for tracing page sizes returned by the above method; enabled by
302 // TracePageSizes. The region_{min,max}_size parameters should be the values
303 // passed to page_size_for_region() and page_size should be the result of that
304 // call. The (optional) base and size parameters should come from the
305 // ReservedSpace base() and size() methods.
306 static void trace_page_sizes(const char* str, const size_t* page_sizes,
307 int count) PRODUCT_RETURN;
308 static void trace_page_sizes(const char* str, const size_t region_min_size,
309 const size_t region_max_size,
310 const size_t page_size,
311 const char* base = NULL,
312 const size_t size = 0) PRODUCT_RETURN;
313
314 static int vm_allocation_granularity();
315 static char* reserve_memory(size_t bytes, char* addr = 0,
316 size_t alignment_hint = 0);
317 static char* reserve_memory(size_t bytes, char* addr,
318 size_t alignment_hint, MEMFLAGS flags);
319 static char* reserve_memory_aligned(size_t size, size_t alignment);
320 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
321 static void split_reserved_memory(char *base, size_t size,
322 size_t split, bool realloc);
323 static bool commit_memory(char* addr, size_t bytes, bool executable);
324 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
325 bool executable);
326 // Same as commit_memory() that either succeeds or calls
327 // vm_exit_out_of_memory() with the specified mesg.
328 static void commit_memory_or_exit(char* addr, size_t bytes,
329 bool executable, const char* mesg);
330 static void commit_memory_or_exit(char* addr, size_t size,
331 size_t alignment_hint,
332 bool executable, const char* mesg);
333 static bool uncommit_memory(char* addr, size_t bytes);
334 static bool release_memory(char* addr, size_t bytes);
335
336 // Touch memory pages that cover the memory range from start to end (exclusive)
337 // to make the OS back the memory range with actual memory.
338 // Current implementation may not touch the last page if unaligned addresses
339 // are passed.
340 static void pretouch_memory(char* start, char* end);
341
342 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
343 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
344 bool is_committed = true);
345
346 static bool guard_memory(char* addr, size_t bytes);
347 static bool unguard_memory(char* addr, size_t bytes);
348 static bool create_stack_guard_pages(char* addr, size_t bytes);
349 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
350 static bool remove_stack_guard_pages(char* addr, size_t bytes);
351
352 static char* map_memory(int fd, const char* file_name, size_t file_offset,
353 char *addr, size_t bytes, bool read_only = false,
354 bool allow_exec = false);
355 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
356 char *addr, size_t bytes, bool read_only,
357 bool allow_exec);
358 static bool unmap_memory(char *addr, size_t bytes);
359 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
360 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
361
362 // NUMA-specific interface
363 static bool numa_has_static_binding();
364 static bool numa_has_group_homing();
365 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
366 static void numa_make_global(char *addr, size_t bytes);
367 static size_t numa_get_groups_num();
368 static size_t numa_get_leaf_groups(int *ids, size_t size);
369 static bool numa_topology_changed();
370 static int numa_get_group_id();
371
372 // Page manipulation
373 struct page_info {
374 size_t size;
375 int lgrp_id;
376 };
377 static bool get_page_info(char *start, page_info* info);
378 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
379
380 static char* non_memory_address_word();
381 // reserve, commit and pin the entire memory region
382 static char* reserve_memory_special(size_t size, size_t alignment,
383 char* addr, bool executable);
384 static bool release_memory_special(char* addr, size_t bytes);
385 static void large_page_init();
386 static size_t large_page_size();
387 static bool can_commit_large_page_memory();
388 static bool can_execute_large_page_memory();
389
390 // OS interface to polling page
391 static address get_polling_page() { return _polling_page; }
392 static void set_polling_page(address page) { _polling_page = page; }
393 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
394 static void make_polling_page_unreadable();
395 static void make_polling_page_readable();
396
397 // Routines used to serialize the thread state without using membars
398 static void serialize_thread_states();
399
400 // Since we write to the serialize page from every thread, we
401 // want stores to be on unique cache lines whenever possible
402 // in order to minimize CPU cross talk. We pre-compute the
403 // amount to shift the thread* to make this offset unique to
404 // each thread.
405 static int get_serialize_page_shift_count() {
406 return SerializePageShiftCount;
407 }
408
409 static void set_serialize_page_mask(uintptr_t mask) {
410 _serialize_page_mask = mask;
411 }
412
413 static unsigned int get_serialize_page_mask() {
414 return _serialize_page_mask;
415 }
416
417 static void set_memory_serialize_page(address page);
418
419 static address get_memory_serialize_page() {
420 return (address)_mem_serialize_page;
421 }
422
423 static inline void write_memory_serialize_page(JavaThread *thread) {
424 uintptr_t page_offset = ((uintptr_t)thread >>
425 get_serialize_page_shift_count()) &
426 get_serialize_page_mask();
427 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
428 }
429
430 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
431 if (UseMembar) return false;
432 // Previously this function calculated the exact address of this
433 // thread's serialize page, and checked if the faulting address
434 // was equal. However, some platforms mask off faulting addresses
435 // to the page size, so now we just check that the address is
436 // within the page. This makes the thread argument unnecessary,
437 // but we retain the NULL check to preserve existing behavior.
438 if (thread == NULL) return false;
439 address page = (address) _mem_serialize_page;
440 return addr >= page && addr < (page + os::vm_page_size());
441 }
442
443 static void block_on_serialize_page_trap();
444
445 // threads
446
447 enum ThreadType {
448 vm_thread,
449 cgc_thread, // Concurrent GC thread
450 pgc_thread, // Parallel GC thread
451 java_thread,
452 compiler_thread,
453 watcher_thread,
454 os_thread
455 };
456
457 static bool create_thread(Thread* thread,
458 ThreadType thr_type,
459 size_t stack_size = 0);
460 static bool create_main_thread(JavaThread* thread);
461 static bool create_attached_thread(JavaThread* thread);
462 static void pd_start_thread(Thread* thread);
463 static void start_thread(Thread* thread);
464
465 static void initialize_thread(Thread* thr);
466 static void free_thread(OSThread* osthread);
467
468 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
469 static intx current_thread_id();
470 static int current_process_id();
471 static int sleep(Thread* thread, jlong ms, bool interruptable);
472 // Short standalone OS sleep suitable for slow path spin loop.
473 // Ignores Thread.interrupt() (so keep it short).
474 // ms = 0, will sleep for the least amount of time allowed by the OS.
475 static void naked_short_sleep(jlong ms);
476 static void infinite_sleep(); // never returns, use with CAUTION
477 static void naked_yield () ;
478 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
479 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
480
481 static void interrupt(Thread* thread);
482 static bool is_interrupted(Thread* thread, bool clear_interrupted);
483
484 static int pd_self_suspend_thread(Thread* thread);
485
486 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
487 static frame fetch_frame_from_context(void* ucVoid);
488
489 static ExtendedPC get_thread_pc(Thread *thread);
490 static void breakpoint();
491
492 static address current_stack_pointer();
493 static address current_stack_base();
494 static size_t current_stack_size();
495
496 static void verify_stack_alignment() PRODUCT_RETURN;
497
498 static int message_box(const char* title, const char* message);
499 static char* do_you_want_to_debug(const char* message);
500
501 // run cmd in a separate process and return its exit code; or -1 on failures
502 static int fork_and_exec(char *cmd);
503
504 // Call ::exit() on all platforms but Windows
505 static void exit(int num);
506
507 // Terminate the VM, but don't exit the process
508 static void shutdown();
509
510 // Terminate with an error. Default is to generate a core file on platforms
511 // that support such things. This calls shutdown() and then aborts.
512 static void abort(bool dump_core, void *siginfo, void *context);
513 static void abort(bool dump_core = true);
514
515 // Die immediately, no exit hook, no abort hook, no cleanup.
516 static void die();
517
518 // File i/o operations
519 static const int default_file_open_flags();
520 static int open(const char *path, int oflag, int mode);
521 static FILE* open(int fd, const char* mode);
522 static int close(int fd);
523 static jlong lseek(int fd, jlong offset, int whence);
524 static char* native_path(char *path);
525 static int ftruncate(int fd, jlong length);
526 static int fsync(int fd);
527 static int available(int fd, jlong *bytes);
528
529 //File i/o operations
530
531 static size_t read(int fd, void *buf, unsigned int nBytes);
532 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
533 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
534 static size_t write(int fd, const void *buf, unsigned int nBytes);
535
536 // Reading directories.
537 static DIR* opendir(const char* dirname);
538 static int readdir_buf_size(const char *path);
539 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
540 static int closedir(DIR* dirp);
541
542 // Dynamic library extension
543 static const char* dll_file_extension();
544
545 static const char* get_temp_directory();
546 static const char* get_current_directory(char *buf, size_t buflen);
547
548 // Builds a platform-specific full library path given a ld path and lib name
549 // Returns true if buffer contains full path to existing file, false otherwise
550 static bool dll_build_name(char* buffer, size_t size,
551 const char* pathname, const char* fname);
552
553 // Symbol lookup, find nearest function name; basically it implements
554 // dladdr() for all platforms. Name of the nearest function is copied
555 // to buf. Distance from its base address is optionally returned as offset.
556 // If function name is not found, buf[0] is set to '\0' and offset is
557 // set to -1 (if offset is non-NULL).
558 static bool dll_address_to_function_name(address addr, char* buf,
559 int buflen, int* offset);
560
561 // Locate DLL/DSO. On success, full path of the library is copied to
562 // buf, and offset is optionally set to be the distance between addr
563 // and the library's base address. On failure, buf[0] is set to '\0'
564 // and offset is set to -1 (if offset is non-NULL).
565 static bool dll_address_to_library_name(address addr, char* buf,
566 int buflen, int* offset);
567
568 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
569 static bool address_is_in_vm(address addr);
570
571 // Loads .dll/.so and
572 // in case of error it checks if .dll/.so was built for the
573 // same architecture as HotSpot is running on
574 static void* dll_load(const char *name, char *ebuf, int ebuflen);
575
576 // lookup symbol in a shared library
577 static void* dll_lookup(void* handle, const char* name);
578
579 // Unload library
580 static void dll_unload(void *lib);
581
582 // Callback for loaded module information
583 // Input parameters:
584 // char* module_file_name,
585 // address module_base_addr,
586 // address module_top_addr,
587 // void* param
588 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
589
590 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
591
592 // Return the handle of this process
593 static void* get_default_process_handle();
594
595 // Check for static linked agent library
596 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
597 size_t syms_len);
598
599 // Find agent entry point
600 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
601 const char *syms[], size_t syms_len);
602
603 // Print out system information; they are called by fatal error handler.
604 // Output format may be different on different platforms.
605 static void print_os_info(outputStream* st);
606 static void print_os_info_brief(outputStream* st);
607 static void print_cpu_info(outputStream* st);
608 static void pd_print_cpu_info(outputStream* st);
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, void* context);
613 static void print_register_info(outputStream* st, void* context);
614 static void print_siginfo(outputStream* st, void* siginfo);
615 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
616 static void print_date_and_time(outputStream* st);
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 // Determines whether the calling process is being debugged by a user-mode debugger.
623 static bool is_debugger_attached();
624
625 // wait for a key press if PauseAtExit is set
626 static void wait_for_keypress_at_exit(void);
627
628 // The following two functions are used by fatal error handler to trace
629 // native (C) frames. They are not part of frame.hpp/frame.cpp because
630 // frame.hpp/cpp assume thread is JavaThread, and also because different
631 // OS/compiler may have different convention or provide different API to
632 // walk C frames.
633 //
634 // We don't attempt to become a debugger, so we only follow frames if that
635 // does not require a lookup in the unwind table, which is part of the binary
636 // file but may be unsafe to read after a fatal error. So on x86, we can
637 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
638 // possible to walk C stack without having the unwind table.
639 static bool is_first_C_frame(frame *fr);
640 static frame get_sender_for_C_frame(frame *fr);
641
642 // return current frame. pc() and sp() are set to NULL on failure.
643 static frame current_frame();
644
645 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
646
647 // returns a string to describe the exception/signal;
648 // returns NULL if exception_code is not an OS exception/signal.
649 static const char* exception_name(int exception_code, char* buf, size_t buflen);
650
651 // Returns native Java library, loads if necessary
652 static void* native_java_library();
653
654 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
655 static void jvm_path(char *buf, jint buflen);
656
657 // Returns true if we are running in a headless jre.
658 static bool is_headless_jre();
659
660 // JNI names
661 static void print_jni_name_prefix_on(outputStream* st, int args_size);
662 static void print_jni_name_suffix_on(outputStream* st, int args_size);
663
664 // Init os specific system properties values
665 static void init_system_properties_values();
666
667 // IO operations, non-JVM_ version.
668 static int stat(const char* path, struct stat* sbuf);
669 static bool dir_is_empty(const char* path);
670
671 // IO operations on binary files
672 static int create_binary_file(const char* path, bool rewrite_existing);
673 static jlong current_file_offset(int fd);
674 static jlong seek_to_file_offset(int fd, jlong offset);
675
676 // Thread Local Storage
677 static int allocate_thread_local_storage();
678 static void thread_local_storage_at_put(int index, void* value);
679 static void* thread_local_storage_at(int index);
680 static void free_thread_local_storage(int index);
681
682 // Retrieve native stack frames.
683 // Parameter:
684 // stack: an array to storage stack pointers.
685 // frames: size of above array.
686 // toSkip: number of stack frames to skip at the beginning.
687 // Return: number of stack frames captured.
688 static int get_native_stack(address* stack, int size, int toSkip = 0);
689
690 // General allocation (must be MT-safe)
691 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
692 static void* malloc (size_t size, MEMFLAGS flags);
693 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
694 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
695
696 static void free (void *memblock);
697 static bool check_heap(bool force = false); // verify C heap integrity
698 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
699 // Like strdup, but exit VM when strdup() returns NULL
700 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
701
702 #ifndef PRODUCT
703 static julong num_mallocs; // # of calls to malloc/realloc
704 static julong alloc_bytes; // # of bytes allocated
705 static julong num_frees; // # of calls to free
706 static julong free_bytes; // # of bytes freed
707 #endif
708
709 // SocketInterface (ex HPI SocketInterface )
710 static int socket(int domain, int type, int protocol);
711 static int socket_close(int fd);
712 static int recv(int fd, char* buf, size_t nBytes, uint flags);
713 static int send(int fd, char* buf, size_t nBytes, uint flags);
714 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
715 static int connect(int fd, struct sockaddr* him, socklen_t len);
716 static struct hostent* get_host_by_name(char* name);
717
718 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
719 static void signal_init();
720 static void signal_init_pd();
721 static void signal_notify(int signal_number);
722 static void* signal(int signal_number, void* handler);
723 static void signal_raise(int signal_number);
724 static int signal_wait();
725 static int signal_lookup();
726 static void* user_handler();
727 static void terminate_signal_thread();
728 static int sigexitnum_pd();
729
730 // random number generation
731 static long random(); // return 32bit pseudorandom number
732 static void init_random(long initval); // initialize random sequence
733
734 // Structured OS Exception support
735 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
736
737 // On Posix compatible OS it will simply check core dump limits while on Windows
738 // it will check if dump file can be created. Check or prepare a core dump to be
739 // taken at a later point in the same thread in os::abort(). Use the caller
740 // provided buffer as a scratch buffer. The status message which will be written
741 // into the error log either is file location or a short error message, depending
742 // on the checking result.
743 static void check_dump_limit(char* buffer, size_t bufferSize);
744
745 // Get the default path to the core file
746 // Returns the length of the string
747 static int get_core_path(char* buffer, size_t bufferSize);
748
749 // JVMTI & JVM monitoring and management support
750 // The thread_cpu_time() and current_thread_cpu_time() are only
751 // supported if is_thread_cpu_time_supported() returns true.
752 // They are not supported on Solaris T1.
753
754 // Thread CPU Time - return the fast estimate on a platform
755 // On Solaris - call gethrvtime (fast) - user time only
756 // On Linux - fast clock_gettime where available - user+sys
757 // - otherwise: very slow /proc fs - user+sys
758 // On Windows - GetThreadTimes - user+sys
759 static jlong current_thread_cpu_time();
760 static jlong thread_cpu_time(Thread* t);
761
762 // Thread CPU Time with user_sys_cpu_time parameter.
763 //
764 // If user_sys_cpu_time is true, user+sys time is returned.
765 // Otherwise, only user time is returned
766 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
767 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
768
769 // Return a bunch of info about the timers.
770 // Note that the returned info for these two functions may be different
771 // on some platforms
772 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
773 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
774
775 static bool is_thread_cpu_time_supported();
776
777 // System loadavg support. Returns -1 if load average cannot be obtained.
778 static int loadavg(double loadavg[], int nelem);
779
780 // Hook for os specific jvm options that we don't want to abort on seeing
781 static bool obsolete_option(const JavaVMOption *option);
782
783 // Amount beyond the callee frame size that we bang the stack.
784 static int extra_bang_size_in_bytes();
785
786 // Extensions
787 #include "runtime/os_ext.hpp"
788
789 public:
790 class CrashProtectionCallback : public StackObj {
791 public:
792 virtual void call() = 0;
793 };
794
795 // Platform dependent stuff
796 #ifdef TARGET_OS_FAMILY_linux
797 # include "os_linux.hpp"
798 # include "os_posix.hpp"
799 #endif
800 #ifdef TARGET_OS_FAMILY_solaris
801 # include "os_solaris.hpp"
802 # include "os_posix.hpp"
803 #endif
804 #ifdef TARGET_OS_FAMILY_windows
805 # include "os_windows.hpp"
806 #endif
807 #ifdef TARGET_OS_FAMILY_aix
808 # include "os_aix.hpp"
809 # include "os_posix.hpp"
810 #endif
811 #ifdef TARGET_OS_FAMILY_bsd
812 # include "os_posix.hpp"
813 # include "os_bsd.hpp"
814 #endif
815 #ifdef TARGET_OS_ARCH_linux_x86
816 # include "os_linux_x86.hpp"
817 #endif
818 #ifdef TARGET_OS_ARCH_linux_sparc
819 # include "os_linux_sparc.hpp"
820 #endif
821 #ifdef TARGET_OS_ARCH_linux_zero
822 # include "os_linux_zero.hpp"
823 #endif
824 #ifdef TARGET_OS_ARCH_solaris_x86
825 # include "os_solaris_x86.hpp"
826 #endif
827 #ifdef TARGET_OS_ARCH_solaris_sparc
828 # include "os_solaris_sparc.hpp"
829 #endif
830 #ifdef TARGET_OS_ARCH_windows_x86
831 # include "os_windows_x86.hpp"
832 #endif
833 #ifdef TARGET_OS_ARCH_linux_arm
834 # include "os_linux_arm.hpp"
835 #endif
836 #ifdef TARGET_OS_ARCH_linux_ppc
837 # include "os_linux_ppc.hpp"
838 #endif
839 #ifdef TARGET_OS_ARCH_aix_ppc
840 # include "os_aix_ppc.hpp"
841 #endif
842 #ifdef TARGET_OS_ARCH_linux_aarch64
843 # include "os_linux_aarch64.hpp"
844 #endif
845 #ifdef TARGET_OS_ARCH_bsd_x86
846 # include "os_bsd_x86.hpp"
847 #endif
848 #ifdef TARGET_OS_ARCH_bsd_zero
849 # include "os_bsd_zero.hpp"
850 #endif
851
852 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
853 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
854 #endif
855
856 public:
857 #ifndef PLATFORM_PRINT_NATIVE_STACK
858 // No platform-specific code for printing the native stack.
859 static bool platform_print_native_stack(outputStream* st, void* context,
860 char *buf, int buf_size) {
861 return false;
862 }
863 #endif
864
865 // debugging support (mostly used by debug.cpp but also fatal error handler)
866 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
867
868 static bool dont_yield(); // when true, JVM_Yield() is nop
869 static void print_statistics();
870
871 // Thread priority helpers (implemented in OS-specific part)
872 static OSReturn set_native_priority(Thread* thread, int native_prio);
873 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
874 static int java_to_os_priority[CriticalPriority + 1];
875 // Hint to the underlying OS that a task switch would not be good.
876 // Void return because it's a hint and can fail.
877 static void hint_no_preempt();
878 static const char* native_thread_creation_failed_msg() {
879 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
880 }
881
882 // Used at creation if requested by the diagnostic flag PauseAtStartup.
883 // Causes the VM to wait until an external stimulus has been applied
884 // (for Unix, that stimulus is a signal, for Windows, an external
885 // ResumeThread call)
886 static void pause();
887
888 // Builds a platform dependent Agent_OnLoad_<libname> function name
889 // which is used to find statically linked in agents.
890 static char* build_agent_function_name(const char *sym, const char *cname,
891 bool is_absolute_path);
892
893 class SuspendedThreadTaskContext {
894 public:
895 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
896 Thread* thread() const { return _thread; }
897 void* ucontext() const { return _ucontext; }
898 private:
899 Thread* _thread;
900 void* _ucontext;
901 };
902
903 class SuspendedThreadTask {
904 public:
905 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
906 virtual ~SuspendedThreadTask() {}
907 void run();
908 bool is_done() { return _done; }
909 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
910 protected:
911 private:
912 void internal_do_task();
913 Thread* _thread;
914 bool _done;
915 };
916
917 #ifndef TARGET_OS_FAMILY_windows
918 // Suspend/resume support
919 // Protocol:
920 //
921 // a thread starts in SR_RUNNING
922 //
923 // SR_RUNNING can go to
924 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
925 // SR_SUSPEND_REQUEST can go to
926 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
927 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
928 // SR_SUSPENDED can go to
929 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
930 // SR_WAKEUP_REQUEST can go to
931 // * SR_RUNNING when the stopped thread receives the signal
932 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
933 class SuspendResume {
934 public:
935 enum State {
936 SR_RUNNING,
937 SR_SUSPEND_REQUEST,
938 SR_SUSPENDED,
939 SR_WAKEUP_REQUEST
940 };
941
942 private:
943 volatile State _state;
944
945 private:
946 /* try to switch state from state "from" to state "to"
947 * returns the state set after the method is complete
948 */
949 State switch_state(State from, State to);
950
951 public:
952 SuspendResume() : _state(SR_RUNNING) { }
953
954 State state() const { return _state; }
955
956 State request_suspend() {
957 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
958 }
959
960 State cancel_suspend() {
961 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
962 }
963
964 State suspended() {
965 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
966 }
967
968 State request_wakeup() {
969 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
970 }
971
972 State running() {
973 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
974 }
975
976 bool is_running() const {
977 return _state == SR_RUNNING;
978 }
979
980 bool is_suspend_request() const {
981 return _state == SR_SUSPEND_REQUEST;
982 }
983
984 bool is_suspended() const {
985 return _state == SR_SUSPENDED;
986 }
987 };
988 #endif
989
990
991 protected:
992 static long _rand_seed; // seed for random number generator
993 static int _processor_count; // number of processors
994
995 static char* format_boot_path(const char* format_string,
996 const char* home,
997 int home_len,
998 char fileSep,
999 char pathSep);
1000 static bool set_boot_path(char fileSep, char pathSep);
1001 static char** split_path(const char* path, int* n);
1002
1003 };
1004
1005 // Note that "PAUSE" is almost always used with synchronization
1006 // so arguably we should provide Atomic::SpinPause() instead
1007 // of the global SpinPause() with C linkage.
1008 // It'd also be eligible for inlining on many platforms.
1009
1010 extern "C" int SpinPause();
1011
1012 #endif // SHARE_VM_RUNTIME_OS_HPP