1 /*
2 * Copyright (c) 1997, 2013, 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/atomic.hpp"
30 #include "runtime/extendedPC.hpp"
31 #include "runtime/handles.hpp"
32 #include "utilities/top.hpp"
33 #ifdef TARGET_OS_FAMILY_linux
34 # include "jvm_linux.h"
35 # include <setjmp.h>
36 #endif
37 #ifdef TARGET_OS_FAMILY_solaris
38 # include "jvm_solaris.h"
39 # include <setjmp.h>
40 #endif
41 #ifdef TARGET_OS_FAMILY_windows
42 # include "jvm_windows.h"
43 #endif
44 #ifdef TARGET_OS_FAMILY_bsd
45 # include "jvm_bsd.h"
46 # include <setjmp.h>
47 #endif
48
49 class AgentLibrary;
50
51 // os defines the interface to operating system; this includes traditional
52 // OS services (time, I/O) as well as other functionality with system-
53 // dependent code.
54
55 typedef void (*dll_func)(...);
56
57 class Thread;
58 class JavaThread;
59 class Event;
60 class DLL;
61 class FileHandle;
62 template<class E> class GrowableArray;
63
64 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
65
66 // Platform-independent error return values from OS functions
67 enum OSReturn {
68 OS_OK = 0, // Operation was successful
69 OS_ERR = -1, // Operation failed
70 OS_INTRPT = -2, // Operation was interrupted
71 OS_TIMEOUT = -3, // Operation timed out
72 OS_NOMEM = -5, // Operation failed for lack of memory
73 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
74 };
75
76 enum ThreadPriority { // JLS 20.20.1-3
77 NoPriority = -1, // Initial non-priority value
78 MinPriority = 1, // Minimum priority
79 NormPriority = 5, // Normal (non-daemon) priority
80 NearMaxPriority = 9, // High priority, used for VMThread
81 MaxPriority = 10, // Highest priority, used for WatcherThread
82 // ensures that VMThread doesn't starve profiler
83 CriticalPriority = 11 // Critical thread priority
84 };
85
86 // Executable parameter flag for os::commit_memory() and
87 // os::commit_memory_or_exit().
88 const bool ExecMem = true;
89
90 // Typedef for structured exception handling support
91 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
92
93 class os: AllStatic {
94 friend class VMStructs;
95
96 public:
97 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
98
99 private:
100 static OSThread* _starting_thread;
101 static address _polling_page;
102 static volatile int32_t * _mem_serialize_page;
103 static uintptr_t _serialize_page_mask;
104 public:
105 static size_t _page_sizes[page_sizes_max];
106
107 private:
108 static void init_page_sizes(size_t default_page_size) {
109 _page_sizes[0] = default_page_size;
110 _page_sizes[1] = 0; // sentinel
111 }
112
113 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
114 size_t alignment_hint = 0);
115 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
116 static void pd_split_reserved_memory(char *base, size_t size,
117 size_t split, bool realloc);
118 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
119 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
120 bool executable);
121 // Same as pd_commit_memory() that either succeeds or calls
122 // vm_exit_out_of_memory() with the specified mesg.
123 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
124 bool executable, const char* mesg);
125 static void pd_commit_memory_or_exit(char* addr, size_t size,
126 size_t alignment_hint,
127 bool executable, const char* mesg);
128 static bool pd_uncommit_memory(char* addr, size_t bytes);
129 static bool pd_release_memory(char* addr, size_t bytes);
130
131 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
132 char *addr, size_t bytes, bool read_only = false,
133 bool allow_exec = false);
134 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
135 char *addr, size_t bytes, bool read_only,
136 bool allow_exec);
137 static bool pd_unmap_memory(char *addr, size_t bytes);
138 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
139 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
140
141
142 public:
143 static void init(void); // Called before command line parsing
144 static void init_before_ergo(void); // Called after command line parsing
145 // before VM ergonomics processing.
146 static jint init_2(void); // Called after command line parsing
147 // and VM ergonomics processing
148 static void init_globals(void) { // Called from init_globals() in init.cpp
149 init_globals_ext();
150 }
151 static void init_3(void); // Called at the end of vm init
152
153 // File names are case-insensitive on windows only
154 // Override me as needed
155 static int file_name_strcmp(const char* s1, const char* s2);
156
157 static bool getenv(const char* name, char* buffer, int len);
158 static bool have_special_privileges();
159
160 static jlong javaTimeMillis();
161 static jlong javaTimeNanos();
162 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
163 static void run_periodic_checks();
164
165
166 // Returns the elapsed time in seconds since the vm started.
167 static double elapsedTime();
168
169 // Returns real time in seconds since an arbitrary point
170 // in the past.
171 static bool getTimesSecs(double* process_real_time,
172 double* process_user_time,
173 double* process_system_time);
174
175 // Interface to the performance counter
176 static jlong elapsed_counter();
177 static jlong elapsed_frequency();
178
179 // The "virtual time" of a thread is the amount of time a thread has
180 // actually run. The first function indicates whether the OS supports
181 // this functionality for the current thread, and if so:
182 // * the second enables vtime tracking (if that is required).
183 // * the third tells whether vtime is enabled.
184 // * the fourth returns the elapsed virtual time for the current
185 // thread.
186 static bool supports_vtime();
187 static bool enable_vtime();
188 static bool vtime_enabled();
189 static double elapsedVTime();
190
191 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
192 // It is MT safe, but not async-safe, as reading time zone
193 // information may require a lock on some platforms.
194 static char* local_time_string(char *buf, size_t buflen);
195 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
196 // Fill in buffer with current local time as an ISO-8601 string.
197 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
198 // Returns buffer, or NULL if it failed.
199 static char* iso8601_time(char* buffer, size_t buffer_length);
200
201 // Interface for detecting multiprocessor system
202 static inline bool is_MP() {
203 assert(_processor_count > 0, "invalid processor count");
204 return _processor_count > 1 || AssumeMP;
205 }
206 static julong available_memory();
207 static julong physical_memory();
208 static bool has_allocatable_memory_limit(julong* limit);
209 static bool is_server_class_machine();
210
211 // number of CPUs
212 static int processor_count() {
213 return _processor_count;
214 }
215 static void set_processor_count(int count) { _processor_count = count; }
216
217 // Returns the number of CPUs this process is currently allowed to run on.
218 // Note that on some OSes this can change dynamically.
219 static int active_processor_count();
220
221 // Bind processes to processors.
222 // This is a two step procedure:
223 // first you generate a distribution of processes to processors,
224 // then you bind processes according to that distribution.
225 // Compute a distribution for number of processes to processors.
226 // Stores the processor id's into the distribution array argument.
227 // Returns true if it worked, false if it didn't.
228 static bool distribute_processes(uint length, uint* distribution);
229 // Binds the current process to a processor.
230 // Returns true if it worked, false if it didn't.
231 static bool bind_to_processor(uint processor_id);
232
233 // Give a name to the current thread.
234 static void set_native_thread_name(const char *name);
235
236 // Interface for stack banging (predetect possible stack overflow for
237 // exception processing) There are guard pages, and above that shadow
238 // pages for stack overflow checking.
239 static bool uses_stack_guard_pages();
240 static bool allocate_stack_guard_pages();
241 static void bang_stack_shadow_pages();
242 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
243
244 // OS interface to Virtual Memory
245
246 // Return the default page size.
247 static int vm_page_size();
248
249 // Return the page size to use for a region of memory. The min_pages argument
250 // is a hint intended to limit fragmentation; it says the returned page size
251 // should be <= region_max_size / min_pages. Because min_pages is a hint,
252 // this routine may return a size larger than region_max_size / min_pages.
253 //
254 // The current implementation ignores min_pages if a larger page size is an
255 // exact multiple of both region_min_size and region_max_size. This allows
256 // larger pages to be used when doing so would not cause fragmentation; in
257 // particular, a single page can be used when region_min_size ==
258 // region_max_size == a supported page size.
259 static size_t page_size_for_region(size_t region_min_size,
260 size_t region_max_size,
261 uint min_pages);
262 // Return the largest page size that can be used
263 static size_t max_page_size() {
264 // The _page_sizes array is sorted in descending order.
265 return _page_sizes[0];
266 }
267
268 // Methods for tracing page sizes returned by the above method; enabled by
269 // TracePageSizes. The region_{min,max}_size parameters should be the values
270 // passed to page_size_for_region() and page_size should be the result of that
271 // call. The (optional) base and size parameters should come from the
272 // ReservedSpace base() and size() methods.
273 static void trace_page_sizes(const char* str, const size_t* page_sizes,
274 int count) PRODUCT_RETURN;
275 static void trace_page_sizes(const char* str, const size_t region_min_size,
276 const size_t region_max_size,
277 const size_t page_size,
278 const char* base = NULL,
279 const size_t size = 0) PRODUCT_RETURN;
280
281 static int vm_allocation_granularity();
282 static char* reserve_memory(size_t bytes, char* addr = 0,
283 size_t alignment_hint = 0);
284 static char* reserve_memory(size_t bytes, char* addr,
285 size_t alignment_hint, MEMFLAGS flags);
286 static char* reserve_memory_aligned(size_t size, size_t alignment);
287 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
288 static void split_reserved_memory(char *base, size_t size,
289 size_t split, bool realloc);
290 static bool commit_memory(char* addr, size_t bytes, bool executable);
291 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
292 bool executable);
293 // Same as commit_memory() that either succeeds or calls
294 // vm_exit_out_of_memory() with the specified mesg.
295 static void commit_memory_or_exit(char* addr, size_t bytes,
296 bool executable, const char* mesg);
297 static void commit_memory_or_exit(char* addr, size_t size,
298 size_t alignment_hint,
299 bool executable, const char* mesg);
300 static bool uncommit_memory(char* addr, size_t bytes);
301 static bool release_memory(char* addr, size_t bytes);
302
303 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
304 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
305 bool is_committed = true);
306
307 static bool guard_memory(char* addr, size_t bytes);
308 static bool unguard_memory(char* addr, size_t bytes);
309 static bool create_stack_guard_pages(char* addr, size_t bytes);
310 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
311 static bool remove_stack_guard_pages(char* addr, size_t bytes);
312
313 static char* map_memory(int fd, const char* file_name, size_t file_offset,
314 char *addr, size_t bytes, bool read_only = false,
315 bool allow_exec = false);
316 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
317 char *addr, size_t bytes, bool read_only,
318 bool allow_exec);
319 static bool unmap_memory(char *addr, size_t bytes);
320 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
321 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
322
323 // NUMA-specific interface
324 static bool numa_has_static_binding();
325 static bool numa_has_group_homing();
326 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
327 static void numa_make_global(char *addr, size_t bytes);
328 static size_t numa_get_groups_num();
329 static size_t numa_get_leaf_groups(int *ids, size_t size);
330 static bool numa_topology_changed();
331 static int numa_get_group_id();
332
333 // Page manipulation
334 struct page_info {
335 size_t size;
336 int lgrp_id;
337 };
338 static bool get_page_info(char *start, page_info* info);
339 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
340
341 static char* non_memory_address_word();
342 // reserve, commit and pin the entire memory region
343 static char* reserve_memory_special(size_t size, size_t alignment,
344 char* addr, bool executable);
345 static bool release_memory_special(char* addr, size_t bytes);
346 static void large_page_init();
347 static size_t large_page_size();
348 static bool can_commit_large_page_memory();
349 static bool can_execute_large_page_memory();
350
351 // OS interface to polling page
352 static address get_polling_page() { return _polling_page; }
353 static void set_polling_page(address page) { _polling_page = page; }
354 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
355 static void make_polling_page_unreadable();
356 static void make_polling_page_readable();
357
358 // Routines used to serialize the thread state without using membars
359 static void serialize_thread_states();
360
361 // Since we write to the serialize page from every thread, we
362 // want stores to be on unique cache lines whenever possible
363 // in order to minimize CPU cross talk. We pre-compute the
364 // amount to shift the thread* to make this offset unique to
365 // each thread.
366 static int get_serialize_page_shift_count() {
367 return SerializePageShiftCount;
368 }
369
370 static void set_serialize_page_mask(uintptr_t mask) {
371 _serialize_page_mask = mask;
372 }
373
374 static unsigned int get_serialize_page_mask() {
375 return _serialize_page_mask;
376 }
377
378 static void set_memory_serialize_page(address page);
379
380 static address get_memory_serialize_page() {
381 return (address)_mem_serialize_page;
382 }
383
384 static inline void write_memory_serialize_page(JavaThread *thread) {
385 uintptr_t page_offset = ((uintptr_t)thread >>
386 get_serialize_page_shift_count()) &
387 get_serialize_page_mask();
388 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
389 }
390
391 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
392 if (UseMembar) return false;
393 // Previously this function calculated the exact address of this
394 // thread's serialize page, and checked if the faulting address
395 // was equal. However, some platforms mask off faulting addresses
396 // to the page size, so now we just check that the address is
397 // within the page. This makes the thread argument unnecessary,
398 // but we retain the NULL check to preserve existing behaviour.
399 if (thread == NULL) return false;
400 address page = (address) _mem_serialize_page;
401 return addr >= page && addr < (page + os::vm_page_size());
402 }
403
404 static void block_on_serialize_page_trap();
405
406 // threads
407
408 enum ThreadType {
409 vm_thread,
410 cgc_thread, // Concurrent GC thread
411 pgc_thread, // Parallel GC thread
412 java_thread,
413 compiler_thread,
414 watcher_thread,
415 os_thread
416 };
417
418 static bool create_thread(Thread* thread,
419 ThreadType thr_type,
420 size_t stack_size = 0);
421 static bool create_main_thread(JavaThread* thread);
422 static bool create_attached_thread(JavaThread* thread);
423 static void pd_start_thread(Thread* thread);
424 static void start_thread(Thread* thread);
425
426 static void initialize_thread(Thread* thr);
427 static void free_thread(OSThread* osthread);
428
429 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
430 static intx current_thread_id();
431 static int current_process_id();
432 static int sleep(Thread* thread, jlong ms, bool interruptable);
433 static int naked_sleep();
434 static void infinite_sleep(); // never returns, use with CAUTION
435 static void yield(); // Yields to all threads with same priority
436 enum YieldResult {
437 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
438 YIELD_NONEREADY = 0, // No other runnable/ready threads.
439 // platform-specific yield return immediately
440 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
441 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
442 // yield that can be used in lieu of blocking.
443 } ;
444 static YieldResult NakedYield () ;
445 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
446 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
447 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
448 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
449
450 static void interrupt(Thread* thread);
451 static bool is_interrupted(Thread* thread, bool clear_interrupted);
452
453 static int pd_self_suspend_thread(Thread* thread);
454
455 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
456 static frame fetch_frame_from_context(void* ucVoid);
457
458 static ExtendedPC get_thread_pc(Thread *thread);
459 static void breakpoint();
460
461 static address current_stack_pointer();
462 static address current_stack_base();
463 static size_t current_stack_size();
464
465 static void verify_stack_alignment() PRODUCT_RETURN;
466
467 static int message_box(const char* title, const char* message);
468 static char* do_you_want_to_debug(const char* message);
469
470 // run cmd in a separate process and return its exit code; or -1 on failures
471 static int fork_and_exec(char *cmd);
472
473 // Set file to send error reports.
474 static void set_error_file(const char *logfile);
475
476 // os::exit() is merged with vm_exit()
477 // static void exit(int num);
478
479 // Terminate the VM, but don't exit the process
480 static void shutdown();
481
482 // Terminate with an error. Default is to generate a core file on platforms
483 // that support such things. This calls shutdown() and then aborts.
484 static void abort(bool dump_core = true);
485
486 // Die immediately, no exit hook, no abort hook, no cleanup.
487 static void die();
488
489 // File i/o operations
490 static const int default_file_open_flags();
491 static int open(const char *path, int oflag, int mode);
492 static FILE* open(int fd, const char* mode);
493 static int close(int fd);
494 static jlong lseek(int fd, jlong offset, int whence);
495 static char* native_path(char *path);
496 static int ftruncate(int fd, jlong length);
497 static int fsync(int fd);
498 static int available(int fd, jlong *bytes);
499
500 //File i/o operations
501
502 static size_t read(int fd, void *buf, unsigned int nBytes);
503 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
504 static size_t write(int fd, const void *buf, unsigned int nBytes);
505
506 // Reading directories.
507 static DIR* opendir(const char* dirname);
508 static int readdir_buf_size(const char *path);
509 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
510 static int closedir(DIR* dirp);
511
512 // Dynamic library extension
513 static const char* dll_file_extension();
514
515 static const char* get_temp_directory();
516 static const char* get_current_directory(char *buf, size_t buflen);
517
518 // Builds a platform-specific full library path given a ld path and lib name
519 // Returns true if buffer contains full path to existing file, false otherwise
520 static bool dll_build_name(char* buffer, size_t size,
521 const char* pathname, const char* fname);
522
523 // Symbol lookup, find nearest function name; basically it implements
524 // dladdr() for all platforms. Name of the nearest function is copied
525 // to buf. Distance from its base address is optionally returned as offset.
526 // If function name is not found, buf[0] is set to '\0' and offset is
527 // set to -1 (if offset is non-NULL).
528 static bool dll_address_to_function_name(address addr, char* buf,
529 int buflen, int* offset);
530
531 // Locate DLL/DSO. On success, full path of the library is copied to
532 // buf, and offset is optionally set to be the distance between addr
533 // and the library's base address. On failure, buf[0] is set to '\0'
534 // and offset is set to -1 (if offset is non-NULL).
535 static bool dll_address_to_library_name(address addr, char* buf,
536 int buflen, int* offset);
537
538 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
539 static bool address_is_in_vm(address addr);
540
541 // Loads .dll/.so and
542 // in case of error it checks if .dll/.so was built for the
543 // same architecture as Hotspot is running on
544 static void* dll_load(const char *name, char *ebuf, int ebuflen);
545
546 // lookup symbol in a shared library
547 static void* dll_lookup(void* handle, const char* name);
548
549 // Unload library
550 static void dll_unload(void *lib);
551
552 // Return the handle of this process
553 static void* get_default_process_handle();
554
555 // Check for static linked agent library
556 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
557 size_t syms_len);
558
559 // Find agent entry point
560 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
561 const char *syms[], size_t syms_len);
562
563 // Print out system information; they are called by fatal error handler.
564 // Output format may be different on different platforms.
565 static void print_os_info(outputStream* st);
566 static void print_os_info_brief(outputStream* st);
567 static void print_cpu_info(outputStream* st);
568 static void pd_print_cpu_info(outputStream* st);
569 static void print_memory_info(outputStream* st);
570 static void print_dll_info(outputStream* st);
571 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
572 static void print_context(outputStream* st, void* context);
573 static void print_register_info(outputStream* st, void* context);
574 static void print_siginfo(outputStream* st, void* siginfo);
575 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
576 static void print_date_and_time(outputStream* st);
577
578 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
579 static size_t lasterror(char *buf, size_t len);
580 static int get_last_error();
581
582 // Determines whether the calling process is being debugged by a user-mode debugger.
583 static bool is_debugger_attached();
584
585 // wait for a key press if PauseAtExit is set
586 static void wait_for_keypress_at_exit(void);
587
588 // The following two functions are used by fatal error handler to trace
589 // native (C) frames. They are not part of frame.hpp/frame.cpp because
590 // frame.hpp/cpp assume thread is JavaThread, and also because different
591 // OS/compiler may have different convention or provide different API to
592 // walk C frames.
593 //
594 // We don't attempt to become a debugger, so we only follow frames if that
595 // does not require a lookup in the unwind table, which is part of the binary
596 // file but may be unsafe to read after a fatal error. So on x86, we can
597 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
598 // possible to walk C stack without having the unwind table.
599 static bool is_first_C_frame(frame *fr);
600 static frame get_sender_for_C_frame(frame *fr);
601
602 // return current frame. pc() and sp() are set to NULL on failure.
603 static frame current_frame();
604
605 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
606
607 // returns a string to describe the exception/signal;
608 // returns NULL if exception_code is not an OS exception/signal.
609 static const char* exception_name(int exception_code, char* buf, size_t buflen);
610
611 // Returns native Java library, loads if necessary
612 static void* native_java_library();
613
614 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
615 static void jvm_path(char *buf, jint buflen);
616
617 // Returns true if we are running in a headless jre.
618 static bool is_headless_jre();
619
620 // JNI names
621 static void print_jni_name_prefix_on(outputStream* st, int args_size);
622 static void print_jni_name_suffix_on(outputStream* st, int args_size);
623
624 // File conventions
625 static const char* file_separator();
626 static const char* line_separator();
627 static const char* path_separator();
628
629 // Init os specific system properties values
630 static void init_system_properties_values();
631
632 // IO operations, non-JVM_ version.
633 static int stat(const char* path, struct stat* sbuf);
634 static bool dir_is_empty(const char* path);
635
636 // IO operations on binary files
637 static int create_binary_file(const char* path, bool rewrite_existing);
638 static jlong current_file_offset(int fd);
639 static jlong seek_to_file_offset(int fd, jlong offset);
640
641 // Thread Local Storage
642 static int allocate_thread_local_storage();
643 static void thread_local_storage_at_put(int index, void* value);
644 static void* thread_local_storage_at(int index);
645 static void free_thread_local_storage(int index);
646
647 // Stack walk
648 static address get_caller_pc(int n = 0);
649
650 // General allocation (must be MT-safe)
651 static void* malloc (size_t size, MEMFLAGS flags, address caller_pc = 0);
652 static void* realloc (void *memblock, size_t size, MEMFLAGS flags, address caller_pc = 0);
653 static void free (void *memblock, MEMFLAGS flags = mtNone);
654 static bool check_heap(bool force = false); // verify C heap integrity
655 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
656
657 #ifndef PRODUCT
658 static julong num_mallocs; // # of calls to malloc/realloc
659 static julong alloc_bytes; // # of bytes allocated
660 static julong num_frees; // # of calls to free
661 static julong free_bytes; // # of bytes freed
662 #endif
663
664 // SocketInterface (ex HPI SocketInterface )
665 static int socket(int domain, int type, int protocol);
666 static int socket_close(int fd);
667 static int socket_shutdown(int fd, int howto);
668 static int recv(int fd, char* buf, size_t nBytes, uint flags);
669 static int send(int fd, char* buf, size_t nBytes, uint flags);
670 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
671 static int timeout(int fd, long timeout);
672 static int listen(int fd, int count);
673 static int connect(int fd, struct sockaddr* him, socklen_t len);
674 static int bind(int fd, struct sockaddr* him, socklen_t len);
675 static int accept(int fd, struct sockaddr* him, socklen_t* len);
676 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
677 struct sockaddr* from, socklen_t* fromlen);
678 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
679 static int sendto(int fd, char* buf, size_t len, uint flags,
680 struct sockaddr* to, socklen_t tolen);
681 static int socket_available(int fd, jint* pbytes);
682
683 static int get_sock_opt(int fd, int level, int optname,
684 char* optval, socklen_t* optlen);
685 static int set_sock_opt(int fd, int level, int optname,
686 const char* optval, socklen_t optlen);
687 static int get_host_name(char* name, int namelen);
688
689 static struct hostent* get_host_by_name(char* name);
690
691 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
692 static void signal_init();
693 static void signal_init_pd();
694 static void signal_notify(int signal_number);
695 static void* signal(int signal_number, void* handler);
696 static void signal_raise(int signal_number);
697 static int signal_wait();
698 static int signal_lookup();
699 static void* user_handler();
700 static void terminate_signal_thread();
701 static int sigexitnum_pd();
702
703 // random number generation
704 static long random(); // return 32bit pseudorandom number
705 static void init_random(long initval); // initialize random sequence
706
707 // Structured OS Exception support
708 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
709
710 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
711 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
712
713 // Get the default path to the core file
714 // Returns the length of the string
715 static int get_core_path(char* buffer, size_t bufferSize);
716
717 // JVMTI & JVM monitoring and management support
718 // The thread_cpu_time() and current_thread_cpu_time() are only
719 // supported if is_thread_cpu_time_supported() returns true.
720 // They are not supported on Solaris T1.
721
722 // Thread CPU Time - return the fast estimate on a platform
723 // On Solaris - call gethrvtime (fast) - user time only
724 // On Linux - fast clock_gettime where available - user+sys
725 // - otherwise: very slow /proc fs - user+sys
726 // On Windows - GetThreadTimes - user+sys
727 static jlong current_thread_cpu_time();
728 static jlong thread_cpu_time(Thread* t);
729
730 // Thread CPU Time with user_sys_cpu_time parameter.
731 //
732 // If user_sys_cpu_time is true, user+sys time is returned.
733 // Otherwise, only user time is returned
734 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
735 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
736
737 // Return a bunch of info about the timers.
738 // Note that the returned info for these two functions may be different
739 // on some platforms
740 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
741 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
742
743 static bool is_thread_cpu_time_supported();
744
745 // System loadavg support. Returns -1 if load average cannot be obtained.
746 static int loadavg(double loadavg[], int nelem);
747
748 // Hook for os specific jvm options that we don't want to abort on seeing
749 static bool obsolete_option(const JavaVMOption *option);
750
751 // Extensions
752 #include "runtime/os_ext.hpp"
753
754 public:
755 class CrashProtectionCallback : public StackObj {
756 public:
757 virtual void call() = 0;
758 };
759
760 // Platform dependent stuff
761 #ifdef TARGET_OS_FAMILY_linux
762 # include "os_linux.hpp"
763 # include "os_posix.hpp"
764 #endif
765 #ifdef TARGET_OS_FAMILY_solaris
766 # include "os_solaris.hpp"
767 # include "os_posix.hpp"
768 #endif
769 #ifdef TARGET_OS_FAMILY_windows
770 # include "os_windows.hpp"
771 #endif
772 #ifdef TARGET_OS_FAMILY_bsd
773 # include "os_posix.hpp"
774 # include "os_bsd.hpp"
775 #endif
776 #ifdef TARGET_OS_ARCH_linux_x86
777 # include "os_linux_x86.hpp"
778 #endif
779 #ifdef TARGET_OS_ARCH_linux_sparc
780 # include "os_linux_sparc.hpp"
781 #endif
782 #ifdef TARGET_OS_ARCH_linux_zero
783 # include "os_linux_zero.hpp"
784 #endif
785 #ifdef TARGET_OS_ARCH_solaris_x86
786 # include "os_solaris_x86.hpp"
787 #endif
788 #ifdef TARGET_OS_ARCH_solaris_sparc
789 # include "os_solaris_sparc.hpp"
790 #endif
791 #ifdef TARGET_OS_ARCH_windows_x86
792 # include "os_windows_x86.hpp"
793 #endif
794 #ifdef TARGET_OS_ARCH_linux_arm
795 # include "os_linux_arm.hpp"
796 #endif
797 #ifdef TARGET_OS_ARCH_linux_ppc
798 # include "os_linux_ppc.hpp"
799 #endif
800 #ifdef TARGET_OS_ARCH_bsd_x86
801 # include "os_bsd_x86.hpp"
802 #endif
803 #ifdef TARGET_OS_ARCH_bsd_zero
804 # include "os_bsd_zero.hpp"
805 #endif
806
807 public:
808 #ifndef PLATFORM_PRINT_NATIVE_STACK
809 // No platform-specific code for printing the native stack.
810 static bool platform_print_native_stack(outputStream* st, void* context,
811 char *buf, int buf_size) {
812 return false;
813 }
814 #endif
815
816 // debugging support (mostly used by debug.cpp but also fatal error handler)
817 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
818
819 static bool dont_yield(); // when true, JVM_Yield() is nop
820 static void print_statistics();
821
822 // Thread priority helpers (implemented in OS-specific part)
823 static OSReturn set_native_priority(Thread* thread, int native_prio);
824 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
825 static int java_to_os_priority[CriticalPriority + 1];
826 // Hint to the underlying OS that a task switch would not be good.
827 // Void return because it's a hint and can fail.
828 static void hint_no_preempt();
829
830 // Used at creation if requested by the diagnostic flag PauseAtStartup.
831 // Causes the VM to wait until an external stimulus has been applied
832 // (for Unix, that stimulus is a signal, for Windows, an external
833 // ResumeThread call)
834 static void pause();
835
836 // Builds a platform dependent Agent_OnLoad_<libname> function name
837 // which is used to find statically linked in agents.
838 static char* build_agent_function_name(const char *sym, const char *cname,
839 bool is_absolute_path);
840
841 class SuspendedThreadTaskContext {
842 public:
843 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
844 Thread* thread() const { return _thread; }
845 void* ucontext() const { return _ucontext; }
846 private:
847 Thread* _thread;
848 void* _ucontext;
849 };
850
851 class SuspendedThreadTask {
852 public:
853 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
854 virtual ~SuspendedThreadTask() {}
855 void run();
856 bool is_done() { return _done; }
857 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
858 protected:
859 private:
860 void internal_do_task();
861 Thread* _thread;
862 bool _done;
863 };
864
865 #ifndef TARGET_OS_FAMILY_windows
866 // Suspend/resume support
867 // Protocol:
868 //
869 // a thread starts in SR_RUNNING
870 //
871 // SR_RUNNING can go to
872 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
873 // SR_SUSPEND_REQUEST can go to
874 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
875 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
876 // SR_SUSPENDED can go to
877 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
878 // SR_WAKEUP_REQUEST can go to
879 // * SR_RUNNING when the stopped thread receives the signal
880 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
881 class SuspendResume {
882 public:
883 enum State {
884 SR_RUNNING,
885 SR_SUSPEND_REQUEST,
886 SR_SUSPENDED,
887 SR_WAKEUP_REQUEST
888 };
889
890 private:
891 volatile State _state;
892
893 private:
894 /* try to switch state from state "from" to state "to"
895 * returns the state set after the method is complete
896 */
897 State switch_state(State from, State to);
898
899 public:
900 SuspendResume() : _state(SR_RUNNING) { }
901
902 State state() const { return _state; }
903
904 State request_suspend() {
905 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
906 }
907
908 State cancel_suspend() {
909 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
910 }
911
912 State suspended() {
913 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
914 }
915
916 State request_wakeup() {
917 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
918 }
919
920 State running() {
921 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
922 }
923
924 bool is_running() const {
925 return _state == SR_RUNNING;
926 }
927
928 bool is_suspend_request() const {
929 return _state == SR_SUSPEND_REQUEST;
930 }
931
932 bool is_suspended() const {
933 return _state == SR_SUSPENDED;
934 }
935 };
936 #endif
937
938
939 protected:
940 static long _rand_seed; // seed for random number generator
941 static int _processor_count; // number of processors
942
943 static char* format_boot_path(const char* format_string,
944 const char* home,
945 int home_len,
946 char fileSep,
947 char pathSep);
948 static bool set_boot_path(char fileSep, char pathSep);
949 static char** split_path(const char* path, int* n);
950
951 };
952
953 // Note that "PAUSE" is almost always used with synchronization
954 // so arguably we should provide Atomic::SpinPause() instead
955 // of the global SpinPause() with C linkage.
956 // It'd also be eligible for inlining on many platforms.
957
958 extern "C" int SpinPause();
959
960 #endif // SHARE_VM_RUNTIME_OS_HPP