1 /*
2 * Copyright (c) 1997, 2014, 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 template<class E> class GrowableArray;
69
70 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
71
72 // Platform-independent error return values from OS functions
73 enum OSReturn {
74 OS_OK = 0, // Operation was successful
75 OS_ERR = -1, // Operation failed
76 OS_INTRPT = -2, // Operation was interrupted
77 OS_TIMEOUT = -3, // Operation timed out
78 OS_NOMEM = -5, // Operation failed for lack of memory
79 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
80 };
81
82 enum ThreadPriority { // JLS 20.20.1-3
83 NoPriority = -1, // Initial non-priority value
84 MinPriority = 1, // Minimum priority
85 NormPriority = 5, // Normal (non-daemon) priority
86 NearMaxPriority = 9, // High priority, used for VMThread
87 MaxPriority = 10, // Highest priority, used for WatcherThread
88 // ensures that VMThread doesn't starve profiler
89 CriticalPriority = 11 // Critical thread priority
90 };
91
92 // Executable parameter flag for os::commit_memory() and
93 // os::commit_memory_or_exit().
94 const bool ExecMem = true;
95
96 // Typedef for structured exception handling support
97 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
98
99 class os: AllStatic {
100 friend class VMStructs;
101
102 public:
103 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
104
105 private:
106 static OSThread* _starting_thread;
107 static address _polling_page;
108 static volatile int32_t * _mem_serialize_page;
109 static uintptr_t _serialize_page_mask;
110 public:
111 static size_t _page_sizes[page_sizes_max];
112
113 private:
114 static void init_page_sizes(size_t default_page_size) {
115 _page_sizes[0] = default_page_size;
116 _page_sizes[1] = 0; // sentinel
117 }
118
119 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
120 size_t alignment_hint = 0);
121 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
122 static void pd_split_reserved_memory(char *base, size_t size,
123 size_t split, bool realloc);
124 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
125 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
126 bool executable);
127 // Same as pd_commit_memory() that either succeeds or calls
128 // vm_exit_out_of_memory() with the specified mesg.
129 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
130 bool executable, const char* mesg);
131 static void pd_commit_memory_or_exit(char* addr, size_t size,
132 size_t alignment_hint,
133 bool executable, const char* mesg);
134 static bool pd_uncommit_memory(char* addr, size_t bytes);
135 static bool pd_release_memory(char* addr, size_t bytes);
136
137 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
138 char *addr, size_t bytes, bool read_only = false,
139 bool allow_exec = false);
140 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
141 char *addr, size_t bytes, bool read_only,
142 bool allow_exec);
143 static bool pd_unmap_memory(char *addr, size_t bytes);
144 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
145 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
146
147
148 public:
149 static void init(void); // Called before command line parsing
150 static void init_before_ergo(void); // Called after command line parsing
151 // before VM ergonomics processing.
152 static jint init_2(void); // Called after command line parsing
153 // and VM ergonomics processing
154 static void init_globals(void) { // Called from init_globals() in init.cpp
155 init_globals_ext();
156 }
157 static void init_3(void); // Called at the end of vm init
158
159 // File names are case-insensitive on windows only
160 // Override me as needed
161 static int file_name_strcmp(const char* s1, const char* s2);
162
163 static bool getenv(const char* name, char* buffer, int len);
164 static bool have_special_privileges();
165
166 static jlong javaTimeMillis();
167 static jlong javaTimeNanos();
168 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
169 static void run_periodic_checks();
170 static bool supports_monotonic_clock();
171
172
173 // Returns the elapsed time in seconds since the vm started.
174 static double elapsedTime();
175
176 // Returns real time in seconds since an arbitrary point
177 // in the past.
178 static bool getTimesSecs(double* process_real_time,
179 double* process_user_time,
180 double* process_system_time);
181
182 // Interface to the performance counter
183 static jlong elapsed_counter();
184 static jlong elapsed_frequency();
185
186 // The "virtual time" of a thread is the amount of time a thread has
187 // actually run. The first function indicates whether the OS supports
188 // this functionality for the current thread, and if so:
189 // * the second enables vtime tracking (if that is required).
190 // * the third tells whether vtime is enabled.
191 // * the fourth returns the elapsed virtual time for the current
192 // thread.
193 static bool supports_vtime();
194 static bool enable_vtime();
195 static bool vtime_enabled();
196 static double elapsedVTime();
197
198 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
199 // It is MT safe, but not async-safe, as reading time zone
200 // information may require a lock on some platforms.
201 static char* local_time_string(char *buf, size_t buflen);
202 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
203 // Fill in buffer with current local time as an ISO-8601 string.
204 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
205 // Returns buffer, or NULL if it failed.
206 static char* iso8601_time(char* buffer, size_t buffer_length);
207
208 // Interface for detecting multiprocessor system
209 static inline bool is_MP() {
210 assert(_processor_count > 0, "invalid processor count");
211 return _processor_count > 1 || AssumeMP;
212 }
213 static julong available_memory();
214 static julong physical_memory();
215 static bool has_allocatable_memory_limit(julong* limit);
216 static bool is_server_class_machine();
217
218 // number of CPUs
219 static int processor_count() {
220 return _processor_count;
221 }
222 static void set_processor_count(int count) { _processor_count = count; }
223
224 // Returns the number of CPUs this process is currently allowed to run on.
225 // Note that on some OSes this can change dynamically.
226 static int active_processor_count();
227
228 // Bind processes to processors.
229 // This is a two step procedure:
230 // first you generate a distribution of processes to processors,
231 // then you bind processes according to that distribution.
232 // Compute a distribution for number of processes to processors.
233 // Stores the processor id's into the distribution array argument.
234 // Returns true if it worked, false if it didn't.
235 static bool distribute_processes(uint length, uint* distribution);
236 // Binds the current process to a processor.
237 // Returns true if it worked, false if it didn't.
238 static bool bind_to_processor(uint processor_id);
239
240 // Give a name to the current thread.
241 static void set_native_thread_name(const char *name);
242
243 // Interface for stack banging (predetect possible stack overflow for
244 // exception processing) There are guard pages, and above that shadow
245 // pages for stack overflow checking.
246 static bool uses_stack_guard_pages();
247 static bool allocate_stack_guard_pages();
248 static void bang_stack_shadow_pages();
249 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
250
251 // OS interface to Virtual Memory
252
253 // Return the default page size.
254 static int vm_page_size();
255
256 // Returns the page size to use for a region of memory.
257 // region_size / min_pages will always be greater than or equal to the
258 // returned value.
259 static size_t page_size_for_region(size_t region_size, size_t min_pages);
260
261 // Return the largest page size that can be used
262 static size_t max_page_size() {
263 // The _page_sizes array is sorted in descending order.
264 return _page_sizes[0];
265 }
266
267 // Methods for tracing page sizes returned by the above method; enabled by
268 // TracePageSizes. The region_{min,max}_size parameters should be the values
269 // passed to page_size_for_region() and page_size should be the result of that
270 // call. The (optional) base and size parameters should come from the
271 // ReservedSpace base() and size() methods.
272 static void trace_page_sizes(const char* str, const size_t* page_sizes,
273 int count) PRODUCT_RETURN;
274 static void trace_page_sizes(const char* str, const size_t region_min_size,
275 const size_t region_max_size,
276 const size_t page_size,
277 const char* base = NULL,
278 const size_t size = 0) PRODUCT_RETURN;
279
280 static int vm_allocation_granularity();
281 static char* reserve_memory(size_t bytes, char* addr = 0,
282 size_t alignment_hint = 0);
283 static char* reserve_memory(size_t bytes, char* addr,
284 size_t alignment_hint, MEMFLAGS flags);
285 static char* reserve_memory_aligned(size_t size, size_t alignment);
286 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
287 static void split_reserved_memory(char *base, size_t size,
288 size_t split, bool realloc);
289 static bool commit_memory(char* addr, size_t bytes, bool executable);
290 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
291 bool executable);
292 // Same as commit_memory() that either succeeds or calls
293 // vm_exit_out_of_memory() with the specified mesg.
294 static void commit_memory_or_exit(char* addr, size_t bytes,
295 bool executable, const char* mesg);
296 static void commit_memory_or_exit(char* addr, size_t size,
297 size_t alignment_hint,
298 bool executable, const char* mesg);
299 static bool uncommit_memory(char* addr, size_t bytes);
300 static bool release_memory(char* addr, size_t bytes);
301
302 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
303 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
304 bool is_committed = true);
305
306 static bool guard_memory(char* addr, size_t bytes);
307 static bool unguard_memory(char* addr, size_t bytes);
308 static bool create_stack_guard_pages(char* addr, size_t bytes);
309 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
310 static bool remove_stack_guard_pages(char* addr, size_t bytes);
311
312 static char* map_memory(int fd, const char* file_name, size_t file_offset,
313 char *addr, size_t bytes, bool read_only = false,
314 bool allow_exec = false);
315 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
316 char *addr, size_t bytes, bool read_only,
317 bool allow_exec);
318 static bool unmap_memory(char *addr, size_t bytes);
319 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
320 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
321
322 // NUMA-specific interface
323 static bool numa_has_static_binding();
324 static bool numa_has_group_homing();
325 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
326 static void numa_make_global(char *addr, size_t bytes);
327 static size_t numa_get_groups_num();
328 static size_t numa_get_leaf_groups(int *ids, size_t size);
329 static bool numa_topology_changed();
330 static int numa_get_group_id();
331
332 // Page manipulation
333 struct page_info {
334 size_t size;
335 int lgrp_id;
336 };
337 static bool get_page_info(char *start, page_info* info);
338 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
339
340 static char* non_memory_address_word();
341 // reserve, commit and pin the entire memory region
342 static char* reserve_memory_special(size_t size, size_t alignment,
343 char* addr, bool executable);
344 static bool release_memory_special(char* addr, size_t bytes);
345 static void large_page_init();
346 static size_t large_page_size();
347 static bool can_commit_large_page_memory();
348 static bool can_execute_large_page_memory();
349
350 // OS interface to polling page
351 static address get_polling_page() { return _polling_page; }
352 static void set_polling_page(address page) { _polling_page = page; }
353 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
354 static void make_polling_page_unreadable();
355 static void make_polling_page_readable();
356
357 // Routines used to serialize the thread state without using membars
358 static void serialize_thread_states();
359
360 // Since we write to the serialize page from every thread, we
361 // want stores to be on unique cache lines whenever possible
362 // in order to minimize CPU cross talk. We pre-compute the
363 // amount to shift the thread* to make this offset unique to
364 // each thread.
365 static int get_serialize_page_shift_count() {
366 return SerializePageShiftCount;
367 }
368
369 static void set_serialize_page_mask(uintptr_t mask) {
370 _serialize_page_mask = mask;
371 }
372
373 static unsigned int get_serialize_page_mask() {
374 return _serialize_page_mask;
375 }
376
377 static void set_memory_serialize_page(address page);
378
379 static address get_memory_serialize_page() {
380 return (address)_mem_serialize_page;
381 }
382
383 static inline void write_memory_serialize_page(JavaThread *thread) {
384 uintptr_t page_offset = ((uintptr_t)thread >>
385 get_serialize_page_shift_count()) &
386 get_serialize_page_mask();
387 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
388 }
389
390 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
391 if (UseMembar) return false;
392 // Previously this function calculated the exact address of this
393 // thread's serialize page, and checked if the faulting address
394 // was equal. However, some platforms mask off faulting addresses
395 // to the page size, so now we just check that the address is
396 // within the page. This makes the thread argument unnecessary,
397 // but we retain the NULL check to preserve existing behavior.
398 if (thread == NULL) return false;
399 address page = (address) _mem_serialize_page;
400 return addr >= page && addr < (page + os::vm_page_size());
401 }
402
403 static void block_on_serialize_page_trap();
404
405 // threads
406
407 enum ThreadType {
408 vm_thread,
409 cgc_thread, // Concurrent GC thread
410 pgc_thread, // Parallel GC thread
411 java_thread,
412 compiler_thread,
413 watcher_thread,
414 os_thread
415 };
416
417 static bool create_thread(Thread* thread,
418 ThreadType thr_type,
419 size_t stack_size = 0);
420 static bool create_main_thread(JavaThread* thread);
421 static bool create_attached_thread(JavaThread* thread);
422 static void pd_start_thread(Thread* thread);
423 static void start_thread(Thread* thread);
424
425 static void initialize_thread(Thread* thr);
426 static void free_thread(OSThread* osthread);
427
428 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
429 static intx current_thread_id();
430 static int current_process_id();
431 static int sleep(Thread* thread, jlong ms, bool interruptable);
432 // Short standalone OS sleep suitable for slow path spin loop.
433 // Ignores Thread.interrupt() (so keep it short).
434 // ms = 0, will sleep for the least amount of time allowed by the OS.
435 static void naked_short_sleep(jlong ms);
436 static void infinite_sleep(); // never returns, use with CAUTION
437 static void yield(); // Yields to all threads with same priority
438 enum YieldResult {
439 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
440 YIELD_NONEREADY = 0, // No other runnable/ready threads.
441 // platform-specific yield return immediately
442 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
443 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
444 // yield that can be used in lieu of blocking.
445 } ;
446 static YieldResult NakedYield () ;
447 static void yield_all(); // Yields to all other threads including lower priority
448 // (for the default scheduling policy)
449 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
450 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
451
452 static void interrupt(Thread* thread);
453 static bool is_interrupted(Thread* thread, bool clear_interrupted);
454
455 static int pd_self_suspend_thread(Thread* thread);
456
457 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
458 static frame fetch_frame_from_context(void* ucVoid);
459
460 static ExtendedPC get_thread_pc(Thread *thread);
461 static void breakpoint();
462
463 static address current_stack_pointer();
464 static address current_stack_base();
465 static size_t current_stack_size();
466
467 static void verify_stack_alignment() PRODUCT_RETURN;
468
469 static int message_box(const char* title, const char* message);
470 static char* do_you_want_to_debug(const char* message);
471
472 // run cmd in a separate process and return its exit code; or -1 on failures
473 static int fork_and_exec(char *cmd);
474
475 // Set file to send error reports.
476 static void set_error_file(const char *logfile);
477
478 // os::exit() is merged with vm_exit()
479 // static void exit(int num);
480
481 // Terminate the VM, but don't exit the process
482 static void shutdown();
483
484 // Terminate with an error. Default is to generate a core file on platforms
485 // that support such things. This calls shutdown() and then aborts.
486 static void abort(bool dump_core = true);
487
488 // Die immediately, no exit hook, no abort hook, no cleanup.
489 static void die();
490
491 // File i/o operations
492 static const int default_file_open_flags();
493 static int open(const char *path, int oflag, int mode);
494 static FILE* open(int fd, const char* mode);
495 static int close(int fd);
496 static jlong lseek(int fd, jlong offset, int whence);
497 static char* native_path(char *path);
498 static int ftruncate(int fd, jlong length);
499 static int fsync(int fd);
500 static int available(int fd, jlong *bytes);
501
502 //File i/o operations
503
504 static size_t read(int fd, void *buf, unsigned int nBytes);
505 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
506 static size_t write(int fd, const void *buf, unsigned int nBytes);
507
508 // Reading directories.
509 static DIR* opendir(const char* dirname);
510 static int readdir_buf_size(const char *path);
511 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
512 static int closedir(DIR* dirp);
513
514 // Dynamic library extension
515 static const char* dll_file_extension();
516
517 static const char* get_temp_directory();
518 static const char* get_current_directory(char *buf, size_t buflen);
519
520 // Builds a platform-specific full library path given a ld path and lib name
521 // Returns true if buffer contains full path to existing file, false otherwise
522 static bool dll_build_name(char* buffer, size_t size,
523 const char* pathname, const char* fname);
524
525 // Symbol lookup, find nearest function name; basically it implements
526 // dladdr() for all platforms. Name of the nearest function is copied
527 // to buf. Distance from its base address is optionally returned as offset.
528 // If function name is not found, buf[0] is set to '\0' and offset is
529 // set to -1 (if offset is non-NULL).
530 static bool dll_address_to_function_name(address addr, char* buf,
531 int buflen, int* offset);
532
533 // Locate DLL/DSO. On success, full path of the library is copied to
534 // buf, and offset is optionally set to be the distance between addr
535 // and the library's base address. On failure, buf[0] is set to '\0'
536 // and offset is set to -1 (if offset is non-NULL).
537 static bool dll_address_to_library_name(address addr, char* buf,
538 int buflen, int* offset);
539
540 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
541 static bool address_is_in_vm(address addr);
542
543 // Loads .dll/.so and
544 // in case of error it checks if .dll/.so was built for the
545 // same architecture as HotSpot is running on
546 static void* dll_load(const char *name, char *ebuf, int ebuflen);
547
548 // lookup symbol in a shared library
549 static void* dll_lookup(void* handle, const char* name);
550
551 // Unload library
552 static void dll_unload(void *lib);
553
554 // Return the handle of this process
555 static void* get_default_process_handle();
556
557 // Check for static linked agent library
558 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
559 size_t syms_len);
560
561 // Find agent entry point
562 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
563 const char *syms[], size_t syms_len);
564
565 // Print out system information; they are called by fatal error handler.
566 // Output format may be different on different platforms.
567 static void print_os_info(outputStream* st);
568 static void print_os_info_brief(outputStream* st);
569 static void print_cpu_info(outputStream* st);
570 static void pd_print_cpu_info(outputStream* st);
571 static void print_memory_info(outputStream* st);
572 static void print_dll_info(outputStream* st);
573 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
574 static void print_context(outputStream* st, void* context);
575 static void print_register_info(outputStream* st, void* context);
576 static void print_siginfo(outputStream* st, void* siginfo);
577 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
578 static void print_date_and_time(outputStream* st);
579
580 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
581 static size_t lasterror(char *buf, size_t len);
582 static int get_last_error();
583
584 // Determines whether the calling process is being debugged by a user-mode debugger.
585 static bool is_debugger_attached();
586
587 // wait for a key press if PauseAtExit is set
588 static void wait_for_keypress_at_exit(void);
589
590 // The following two functions are used by fatal error handler to trace
591 // native (C) frames. They are not part of frame.hpp/frame.cpp because
592 // frame.hpp/cpp assume thread is JavaThread, and also because different
593 // OS/compiler may have different convention or provide different API to
594 // walk C frames.
595 //
596 // We don't attempt to become a debugger, so we only follow frames if that
597 // does not require a lookup in the unwind table, which is part of the binary
598 // file but may be unsafe to read after a fatal error. So on x86, we can
599 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
600 // possible to walk C stack without having the unwind table.
601 static bool is_first_C_frame(frame *fr);
602 static frame get_sender_for_C_frame(frame *fr);
603
604 // return current frame. pc() and sp() are set to NULL on failure.
605 static frame current_frame();
606
607 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
608
609 // returns a string to describe the exception/signal;
610 // returns NULL if exception_code is not an OS exception/signal.
611 static const char* exception_name(int exception_code, char* buf, size_t buflen);
612
613 // Returns native Java library, loads if necessary
614 static void* native_java_library();
615
616 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
617 static void jvm_path(char *buf, jint buflen);
618
619 // Returns true if we are running in a headless jre.
620 static bool is_headless_jre();
621
622 // JNI names
623 static void print_jni_name_prefix_on(outputStream* st, int args_size);
624 static void print_jni_name_suffix_on(outputStream* st, int args_size);
625
626 // File conventions
627 static const char* file_separator();
628 static const char* line_separator();
629 static const char* path_separator();
630
631 // Init os specific system properties values
632 static void init_system_properties_values();
633
634 // IO operations, non-JVM_ version.
635 static int stat(const char* path, struct stat* sbuf);
636 static bool dir_is_empty(const char* path);
637
638 // IO operations on binary files
639 static int create_binary_file(const char* path, bool rewrite_existing);
640 static jlong current_file_offset(int fd);
641 static jlong seek_to_file_offset(int fd, jlong offset);
642
643 // Thread Local Storage
644 static int allocate_thread_local_storage();
645 static void thread_local_storage_at_put(int index, void* value);
646 static void* thread_local_storage_at(int index);
647 static void free_thread_local_storage(int index);
648
649 // Stack walk
650 static address get_caller_pc(int n = 0);
651
652 // General allocation (must be MT-safe)
653 static void* malloc (size_t size, MEMFLAGS flags, address caller_pc = 0);
654 static void* realloc (void *memblock, size_t size, MEMFLAGS flags, address caller_pc = 0);
655 static void free (void *memblock, MEMFLAGS flags = mtNone);
656 static bool check_heap(bool force = false); // verify C heap integrity
657 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
658
659 #ifndef PRODUCT
660 static julong num_mallocs; // # of calls to malloc/realloc
661 static julong alloc_bytes; // # of bytes allocated
662 static julong num_frees; // # of calls to free
663 static julong free_bytes; // # of bytes freed
664 #endif
665
666 // SocketInterface (ex HPI SocketInterface )
667 static int socket(int domain, int type, int protocol);
668 static int socket_close(int fd);
669 static int socket_shutdown(int fd, int howto);
670 static int recv(int fd, char* buf, size_t nBytes, uint flags);
671 static int send(int fd, char* buf, size_t nBytes, uint flags);
672 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
673 static int timeout(int fd, long timeout);
674 static int listen(int fd, int count);
675 static int connect(int fd, struct sockaddr* him, socklen_t len);
676 static int bind(int fd, struct sockaddr* him, socklen_t len);
677 static int accept(int fd, struct sockaddr* him, socklen_t* len);
678 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
679 struct sockaddr* from, socklen_t* fromlen);
680 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
681 static int sendto(int fd, char* buf, size_t len, uint flags,
682 struct sockaddr* to, socklen_t tolen);
683 static int socket_available(int fd, jint* pbytes);
684
685 static int get_sock_opt(int fd, int level, int optname,
686 char* optval, socklen_t* optlen);
687 static int set_sock_opt(int fd, int level, int optname,
688 const char* optval, socklen_t optlen);
689 static int get_host_name(char* name, int namelen);
690
691 static struct hostent* get_host_by_name(char* name);
692
693 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
694 static void signal_init();
695 static void signal_init_pd();
696 static void signal_notify(int signal_number);
697 static void* signal(int signal_number, void* handler);
698 static void signal_raise(int signal_number);
699 static int signal_wait();
700 static int signal_lookup();
701 static void* user_handler();
702 static void terminate_signal_thread();
703 static int sigexitnum_pd();
704
705 // random number generation
706 static long random(); // return 32bit pseudorandom number
707 static void init_random(long initval); // initialize random sequence
708
709 // Structured OS Exception support
710 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
711
712 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
713 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
714
715 // Get the default path to the core file
716 // Returns the length of the string
717 static int get_core_path(char* buffer, size_t bufferSize);
718
719 // JVMTI & JVM monitoring and management support
720 // The thread_cpu_time() and current_thread_cpu_time() are only
721 // supported if is_thread_cpu_time_supported() returns true.
722 // They are not supported on Solaris T1.
723
724 // Thread CPU Time - return the fast estimate on a platform
725 // On Solaris - call gethrvtime (fast) - user time only
726 // On Linux - fast clock_gettime where available - user+sys
727 // - otherwise: very slow /proc fs - user+sys
728 // On Windows - GetThreadTimes - user+sys
729 static jlong current_thread_cpu_time();
730 static jlong thread_cpu_time(Thread* t);
731
732 // Thread CPU Time with user_sys_cpu_time parameter.
733 //
734 // If user_sys_cpu_time is true, user+sys time is returned.
735 // Otherwise, only user time is returned
736 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
737 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
738
739 // Return a bunch of info about the timers.
740 // Note that the returned info for these two functions may be different
741 // on some platforms
742 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
743 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
744
745 static bool is_thread_cpu_time_supported();
746
747 // System loadavg support. Returns -1 if load average cannot be obtained.
748 static int loadavg(double loadavg[], int nelem);
749
750 // Hook for os specific jvm options that we don't want to abort on seeing
751 static bool obsolete_option(const JavaVMOption *option);
752
753 // Extensions
754 #include "runtime/os_ext.hpp"
755
756 public:
757 class CrashProtectionCallback : public StackObj {
758 public:
759 virtual void call() = 0;
760 };
761
762 // Platform dependent stuff
763 #ifdef TARGET_OS_FAMILY_linux
764 # include "os_linux.hpp"
765 # include "os_posix.hpp"
766 #endif
767 #ifdef TARGET_OS_FAMILY_solaris
768 # include "os_solaris.hpp"
769 # include "os_posix.hpp"
770 #endif
771 #ifdef TARGET_OS_FAMILY_windows
772 # include "os_windows.hpp"
773 #endif
774 #ifdef TARGET_OS_FAMILY_aix
775 # include "os_aix.hpp"
776 # include "os_posix.hpp"
777 #endif
778 #ifdef TARGET_OS_FAMILY_bsd
779 # include "os_posix.hpp"
780 # include "os_bsd.hpp"
781 #endif
782 #ifdef TARGET_OS_ARCH_linux_x86
783 # include "os_linux_x86.hpp"
784 #endif
785 #ifdef TARGET_OS_ARCH_linux_sparc
786 # include "os_linux_sparc.hpp"
787 #endif
788 #ifdef TARGET_OS_ARCH_linux_zero
789 # include "os_linux_zero.hpp"
790 #endif
791 #ifdef TARGET_OS_ARCH_solaris_x86
792 # include "os_solaris_x86.hpp"
793 #endif
794 #ifdef TARGET_OS_ARCH_solaris_sparc
795 # include "os_solaris_sparc.hpp"
796 #endif
797 #ifdef TARGET_OS_ARCH_windows_x86
798 # include "os_windows_x86.hpp"
799 #endif
800 #ifdef TARGET_OS_ARCH_linux_arm
801 # include "os_linux_arm.hpp"
802 #endif
803 #ifdef TARGET_OS_ARCH_linux_ppc
804 # include "os_linux_ppc.hpp"
805 #endif
806 #ifdef TARGET_OS_ARCH_aix_ppc
807 # include "os_aix_ppc.hpp"
808 #endif
809 #ifdef TARGET_OS_ARCH_bsd_x86
810 # include "os_bsd_x86.hpp"
811 #endif
812 #ifdef TARGET_OS_ARCH_bsd_zero
813 # include "os_bsd_zero.hpp"
814 #endif
815
816 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
817 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
818 #endif
819
820 public:
821 #ifndef PLATFORM_PRINT_NATIVE_STACK
822 // No platform-specific code for printing the native stack.
823 static bool platform_print_native_stack(outputStream* st, void* context,
824 char *buf, int buf_size) {
825 return false;
826 }
827 #endif
828
829 // debugging support (mostly used by debug.cpp but also fatal error handler)
830 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
831
832 static bool dont_yield(); // when true, JVM_Yield() is nop
833 static void print_statistics();
834
835 // Thread priority helpers (implemented in OS-specific part)
836 static OSReturn set_native_priority(Thread* thread, int native_prio);
837 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
838 static int java_to_os_priority[CriticalPriority + 1];
839 // Hint to the underlying OS that a task switch would not be good.
840 // Void return because it's a hint and can fail.
841 static void hint_no_preempt();
842 static const char* native_thread_creation_failed_msg() {
843 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
844 }
845
846 // Used at creation if requested by the diagnostic flag PauseAtStartup.
847 // Causes the VM to wait until an external stimulus has been applied
848 // (for Unix, that stimulus is a signal, for Windows, an external
849 // ResumeThread call)
850 static void pause();
851
852 // Builds a platform dependent Agent_OnLoad_<libname> function name
853 // which is used to find statically linked in agents.
854 static char* build_agent_function_name(const char *sym, const char *cname,
855 bool is_absolute_path);
856
857 class SuspendedThreadTaskContext {
858 public:
859 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
860 Thread* thread() const { return _thread; }
861 void* ucontext() const { return _ucontext; }
862 private:
863 Thread* _thread;
864 void* _ucontext;
865 };
866
867 class SuspendedThreadTask {
868 public:
869 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
870 virtual ~SuspendedThreadTask() {}
871 void run();
872 bool is_done() { return _done; }
873 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
874 protected:
875 private:
876 void internal_do_task();
877 Thread* _thread;
878 bool _done;
879 };
880
881 #ifndef TARGET_OS_FAMILY_windows
882 // Suspend/resume support
883 // Protocol:
884 //
885 // a thread starts in SR_RUNNING
886 //
887 // SR_RUNNING can go to
888 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
889 // SR_SUSPEND_REQUEST can go to
890 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
891 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
892 // SR_SUSPENDED can go to
893 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
894 // SR_WAKEUP_REQUEST can go to
895 // * SR_RUNNING when the stopped thread receives the signal
896 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
897 class SuspendResume {
898 public:
899 enum State {
900 SR_RUNNING,
901 SR_SUSPEND_REQUEST,
902 SR_SUSPENDED,
903 SR_WAKEUP_REQUEST
904 };
905
906 private:
907 volatile State _state;
908
909 private:
910 /* try to switch state from state "from" to state "to"
911 * returns the state set after the method is complete
912 */
913 State switch_state(State from, State to);
914
915 public:
916 SuspendResume() : _state(SR_RUNNING) { }
917
918 State state() const { return _state; }
919
920 State request_suspend() {
921 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
922 }
923
924 State cancel_suspend() {
925 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
926 }
927
928 State suspended() {
929 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
930 }
931
932 State request_wakeup() {
933 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
934 }
935
936 State running() {
937 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
938 }
939
940 bool is_running() const {
941 return _state == SR_RUNNING;
942 }
943
944 bool is_suspend_request() const {
945 return _state == SR_SUSPEND_REQUEST;
946 }
947
948 bool is_suspended() const {
949 return _state == SR_SUSPENDED;
950 }
951 };
952 #endif
953
954
955 protected:
956 static long _rand_seed; // seed for random number generator
957 static int _processor_count; // number of processors
958
959 static char* format_boot_path(const char* format_string,
960 const char* home,
961 int home_len,
962 char fileSep,
963 char pathSep);
964 static bool set_boot_path(char fileSep, char pathSep);
965 static char** split_path(const char* path, int* n);
966
967 };
968
969 // Note that "PAUSE" is almost always used with synchronization
970 // so arguably we should provide Atomic::SpinPause() instead
971 // of the global SpinPause() with C linkage.
972 // It'd also be eligible for inlining on many platforms.
973
974 extern "C" int SpinPause();
975
976 #endif // SHARE_VM_RUNTIME_OS_HPP