1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_OS_HPP
26 #define SHARE_VM_RUNTIME_OS_HPP
27
28 #include "jvm.h"
29 #include "jvmtifiles/jvmti.h"
30 #include "metaprogramming/isRegisteredEnum.hpp"
31 #include "metaprogramming/integralConstant.hpp"
32 #include "runtime/extendedPC.hpp"
33 #include "utilities/exceptions.hpp"
34 #include "utilities/ostream.hpp"
35 #include "utilities/macros.hpp"
36 #ifndef _WINDOWS
37 # include <setjmp.h>
38 #endif
39 #ifdef __APPLE__
40 # include <mach/mach_time.h>
41 #endif
42
43 class AgentLibrary;
44 class frame;
45
46 // os defines the interface to operating system; this includes traditional
47 // OS services (time, I/O) as well as other functionality with system-
48 // dependent code.
49
50 typedef void (*dll_func)(...);
51
52 class Thread;
53 class JavaThread;
54 class Event;
55 class DLL;
56 class FileHandle;
57 class NativeCallStack;
58 class methodHandle;
59
60 template<class E> class GrowableArray;
61
62 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
63
64 // Platform-independent error return values from OS functions
65 enum OSReturn {
66 OS_OK = 0, // Operation was successful
67 OS_ERR = -1, // Operation failed
68 OS_INTRPT = -2, // Operation was interrupted
69 OS_TIMEOUT = -3, // Operation timed out
70 OS_NOMEM = -5, // Operation failed for lack of memory
71 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
72 };
73
74 enum ThreadPriority { // JLS 20.20.1-3
75 NoPriority = -1, // Initial non-priority value
76 MinPriority = 1, // Minimum priority
77 NormPriority = 5, // Normal (non-daemon) priority
78 NearMaxPriority = 9, // High priority, used for VMThread
79 MaxPriority = 10, // Highest priority, used for WatcherThread
80 // ensures that VMThread doesn't starve profiler
81 CriticalPriority = 11 // Critical thread priority
82 };
83
84 // Executable parameter flag for os::commit_memory() and
85 // os::commit_memory_or_exit().
86 const bool ExecMem = true;
87
88 // Typedef for structured exception handling support
89 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
90
91 class MallocTracker;
92
93 class os: AllStatic {
94 friend class VMStructs;
95 friend class JVMCIVMStructs;
96 friend class MallocTracker;
97
98 #ifdef ASSERT
99 private:
100 static bool _mutex_init_done;
101 public:
102 static void set_mutex_init_done() { _mutex_init_done = true; }
103 static bool mutex_init_done() { return _mutex_init_done; }
104 #endif
105
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 public:
113 static size_t _page_sizes[page_sizes_max];
114
115 private:
116 static void init_page_sizes(size_t default_page_size) {
117 _page_sizes[0] = default_page_size;
118 _page_sizes[1] = 0; // sentinel
119 }
120
121 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
122 size_t alignment_hint = 0);
123 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
124 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc);
125 static void pd_split_reserved_memory(char *base, size_t size,
126 size_t split, bool realloc);
127 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
128 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
129 bool executable);
130 // Same as pd_commit_memory() that either succeeds or calls
131 // vm_exit_out_of_memory() with the specified mesg.
132 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
133 bool executable, const char* mesg);
134 static void pd_commit_memory_or_exit(char* addr, size_t size,
135 size_t alignment_hint,
136 bool executable, const char* mesg);
137 static bool pd_uncommit_memory(char* addr, size_t bytes);
138 static bool pd_release_memory(char* addr, size_t bytes);
139
140 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
141 char *addr, size_t bytes, bool read_only = false,
142 bool allow_exec = false);
143 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
144 char *addr, size_t bytes, bool read_only,
145 bool allow_exec);
146 static bool pd_unmap_memory(char *addr, size_t bytes);
147 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
148 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
149
150 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
151
152 // Get summary strings for system information in buffer provided
153 static void get_summary_cpu_info(char* buf, size_t buflen);
154 static void get_summary_os_info(char* buf, size_t buflen);
155
156 static void initialize_initial_active_processor_count();
157
158 LINUX_ONLY(static void pd_init_container_support();)
159
160 public:
161 static void init(void); // Called before command line parsing
162
163 static void init_container_support() { // Called during command line parsing.
164 LINUX_ONLY(pd_init_container_support();)
165 }
166
167 static void init_before_ergo(void); // Called after command line parsing
168 // before VM ergonomics processing.
169 static jint init_2(void); // Called after command line parsing
170 // and VM ergonomics processing
171 static void init_globals(void) { // Called from init_globals() in init.cpp
172 init_globals_ext();
173 }
174
175 // File names are case-insensitive on windows only
176 // Override me as needed
177 static int file_name_strncmp(const char* s1, const char* s2, size_t num);
178
179 // unset environment variable
180 static bool unsetenv(const char* name);
181
182 static bool have_special_privileges();
183
184 static jlong javaTimeMillis();
185 static jlong javaTimeNanos();
186 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
187 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
188 static void run_periodic_checks();
189 static bool supports_monotonic_clock();
190
191 // Returns the elapsed time in seconds since the vm started.
192 static double elapsedTime();
193
194 // Returns real time in seconds since an arbitrary point
195 // in the past.
196 static bool getTimesSecs(double* process_real_time,
197 double* process_user_time,
198 double* process_system_time);
199
200 // Interface to the performance counter
201 static jlong elapsed_counter();
202 static jlong elapsed_frequency();
203
204 // The "virtual time" of a thread is the amount of time a thread has
205 // actually run. The first function indicates whether the OS supports
206 // this functionality for the current thread, and if so:
207 // * the second enables vtime tracking (if that is required).
208 // * the third tells whether vtime is enabled.
209 // * the fourth returns the elapsed virtual time for the current
210 // thread.
211 static bool supports_vtime();
212 static bool enable_vtime();
213 static bool vtime_enabled();
214 static double elapsedVTime();
215
216 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
217 // It is MT safe, but not async-safe, as reading time zone
218 // information may require a lock on some platforms.
219 static char* local_time_string(char *buf, size_t buflen);
220 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
221 static struct tm* gmtime_pd (const time_t* clock, struct tm* res);
222 // Fill in buffer with current local time as an ISO-8601 string.
223 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
224 // Returns buffer, or NULL if it failed.
225 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false);
226
227 // Interface for detecting multiprocessor system
228 static inline bool is_MP() {
229 // During bootstrap if _processor_count is not yet initialized
230 // we claim to be MP as that is safest. If any platform has a
231 // stub generator that might be triggered in this phase and for
232 // which being declared MP when in fact not, is a problem - then
233 // the bootstrap routine for the stub generator needs to check
234 // the processor count directly and leave the bootstrap routine
235 // in place until called after initialization has ocurred.
236 return (_processor_count != 1);
237 }
238
239 static julong available_memory();
240 static julong physical_memory();
241 static bool has_allocatable_memory_limit(julong* limit);
242 static bool is_server_class_machine();
243
244 // Returns the id of the processor on which the calling thread is currently executing.
245 // The returned value is guaranteed to be between 0 and (os::processor_count() - 1).
246 static uint processor_id();
247
248 // number of CPUs
249 static int processor_count() {
250 return _processor_count;
251 }
252 static void set_processor_count(int count) { _processor_count = count; }
253
254 // Returns the number of CPUs this process is currently allowed to run on.
255 // Note that on some OSes this can change dynamically.
256 static int active_processor_count();
257
258 // At startup the number of active CPUs this process is allowed to run on.
259 // This value does not change dynamically. May be different from active_processor_count().
260 static int initial_active_processor_count() {
261 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
262 return _initial_active_processor_count;
263 }
264
265 // Bind processes to processors.
266 // This is a two step procedure:
267 // first you generate a distribution of processes to processors,
268 // then you bind processes according to that distribution.
269 // Compute a distribution for number of processes to processors.
270 // Stores the processor id's into the distribution array argument.
271 // Returns true if it worked, false if it didn't.
272 static bool distribute_processes(uint length, uint* distribution);
273 // Binds the current process to a processor.
274 // Returns true if it worked, false if it didn't.
275 static bool bind_to_processor(uint processor_id);
276
277 // Give a name to the current thread.
278 static void set_native_thread_name(const char *name);
279
280 // Interface for stack banging (predetect possible stack overflow for
281 // exception processing) There are guard pages, and above that shadow
282 // pages for stack overflow checking.
283 static bool uses_stack_guard_pages();
284 static bool must_commit_stack_guard_pages();
285 static void map_stack_shadow_pages(address sp);
286 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
287
288 // Find committed memory region within specified range (start, start + size),
289 // return true if found any
290 static bool committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size);
291
292 // OS interface to Virtual Memory
293
294 // Return the default page size.
295 static int vm_page_size();
296
297 // Returns the page size to use for a region of memory.
298 // region_size / min_pages will always be greater than or equal to the
299 // returned value. The returned value will divide region_size.
300 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
301
302 // Returns the page size to use for a region of memory.
303 // region_size / min_pages will always be greater than or equal to the
304 // returned value. The returned value might not divide region_size.
305 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
306
307 // Return the largest page size that can be used
308 static size_t max_page_size() {
309 // The _page_sizes array is sorted in descending order.
310 return _page_sizes[0];
311 }
312
313 // Return a lower bound for page sizes. Also works before os::init completed.
314 static size_t min_page_size() { return 4 * K; }
315
316 // Methods for tracing page sizes returned by the above method.
317 // The region_{min,max}_size parameters should be the values
318 // passed to page_size_for_region() and page_size should be the result of that
319 // call. The (optional) base and size parameters should come from the
320 // ReservedSpace base() and size() methods.
321 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
322 static void trace_page_sizes(const char* str,
323 const size_t region_min_size,
324 const size_t region_max_size,
325 const size_t page_size,
326 const char* base,
327 const size_t size);
328 static void trace_page_sizes_for_requested_size(const char* str,
329 const size_t requested_size,
330 const size_t page_size,
331 const size_t alignment,
332 const char* base,
333 const size_t size);
334
335 static int vm_allocation_granularity();
336 static char* reserve_memory(size_t bytes, char* addr = 0,
337 size_t alignment_hint = 0, int file_desc = -1);
338 static char* reserve_memory(size_t bytes, char* addr,
339 size_t alignment_hint, MEMFLAGS flags);
340 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1);
341 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1);
342 static void split_reserved_memory(char *base, size_t size,
343 size_t split, bool realloc);
344 static bool commit_memory(char* addr, size_t bytes, bool executable);
345 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
346 bool executable);
347 // Same as commit_memory() that either succeeds or calls
348 // vm_exit_out_of_memory() with the specified mesg.
349 static void commit_memory_or_exit(char* addr, size_t bytes,
350 bool executable, const char* mesg);
351 static void commit_memory_or_exit(char* addr, size_t size,
352 size_t alignment_hint,
353 bool executable, const char* mesg);
354 static bool uncommit_memory(char* addr, size_t bytes);
355 static bool release_memory(char* addr, size_t bytes);
356
357 // Touch memory pages that cover the memory range from start to end (exclusive)
358 // to make the OS back the memory range with actual memory.
359 // Current implementation may not touch the last page if unaligned addresses
360 // are passed.
361 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
362
363 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
364 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
365 bool is_committed = true);
366
367 static bool guard_memory(char* addr, size_t bytes);
368 static bool unguard_memory(char* addr, size_t bytes);
369 static bool create_stack_guard_pages(char* addr, size_t bytes);
370 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
371 static bool remove_stack_guard_pages(char* addr, size_t bytes);
372 // Helper function to create a new file with template jvmheap.XXXXXX.
373 // Returns a valid fd on success or else returns -1
374 static int create_file_for_heap(const char* dir);
375 // Map memory to the file referred by fd. This function is slightly different from map_memory()
376 // and is added to be used for implementation of -XX:AllocateHeapAt
377 static char* map_memory_to_file(char* base, size_t size, int fd);
378 // Replace existing reserved memory with file mapping
379 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd);
380
381 static char* map_memory(int fd, const char* file_name, size_t file_offset,
382 char *addr, size_t bytes, bool read_only = false,
383 bool allow_exec = false);
384 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
385 char *addr, size_t bytes, bool read_only,
386 bool allow_exec);
387 static bool unmap_memory(char *addr, size_t bytes);
388 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
389 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
390
391 // NUMA-specific interface
392 static bool numa_has_static_binding();
393 static bool numa_has_group_homing();
394 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
395 static void numa_make_global(char *addr, size_t bytes);
396 static size_t numa_get_groups_num();
397 static size_t numa_get_leaf_groups(int *ids, size_t size);
398 static bool numa_topology_changed();
399 static int numa_get_group_id();
400
401 // Page manipulation
402 struct page_info {
403 size_t size;
404 int lgrp_id;
405 };
406 static bool get_page_info(char *start, page_info* info);
407 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
408
409 static char* non_memory_address_word();
410 // reserve, commit and pin the entire memory region
411 static char* reserve_memory_special(size_t size, size_t alignment,
412 char* addr, bool executable);
413 static bool release_memory_special(char* addr, size_t bytes);
414 static void large_page_init();
415 static size_t large_page_size();
416 static bool can_commit_large_page_memory();
417 static bool can_execute_large_page_memory();
418
419 // OS interface to polling page
420 static address get_polling_page() { return _polling_page; }
421 static void set_polling_page(address page) { _polling_page = page; }
422 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
423 static void make_polling_page_unreadable();
424 static void make_polling_page_readable();
425
426 // Check if pointer points to readable memory (by 4-byte read access)
427 static bool is_readable_pointer(const void* p);
428 static bool is_readable_range(const void* from, const void* to);
429
430 // threads
431
432 enum ThreadType {
433 vm_thread,
434 cgc_thread, // Concurrent GC thread
435 pgc_thread, // Parallel GC thread
436 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads.
437 compiler_thread,
438 watcher_thread,
439 os_thread
440 };
441
442 static bool create_thread(Thread* thread,
443 ThreadType thr_type,
444 size_t req_stack_size = 0);
445
446 // The "main thread", also known as "starting thread", is the thread
447 // that loads/creates the JVM via JNI_CreateJavaVM.
448 static bool create_main_thread(JavaThread* thread);
449
450 // The primordial thread is the initial process thread. The java
451 // launcher never uses the primordial thread as the main thread, but
452 // applications that host the JVM directly may do so. Some platforms
453 // need special-case handling of the primordial thread if it attaches
454 // to the VM.
455 static bool is_primordial_thread(void)
456 #if defined(_WINDOWS) || defined(BSD)
457 // No way to identify the primordial thread.
458 { return false; }
459 #else
460 ;
461 #endif
462
463 static bool create_attached_thread(JavaThread* thread);
464 static void pd_start_thread(Thread* thread);
465 static void start_thread(Thread* thread);
466
467 static void free_thread(OSThread* osthread);
468
469 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
470 static intx current_thread_id();
471 static int current_process_id();
472 static int sleep(Thread* thread, jlong ms, bool interruptable);
473 // Short standalone OS sleep suitable for slow path spin loop.
474 // Ignores Thread.interrupt() (so keep it short).
475 // ms = 0, will sleep for the least amount of time allowed by the OS.
476 static void naked_short_sleep(jlong ms);
477 static void infinite_sleep(); // never returns, use with CAUTION
478 static void naked_yield () ;
479 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
480 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
481
482 static void interrupt(Thread* thread);
483 static bool is_interrupted(Thread* thread, bool clear_interrupted);
484
485 static int pd_self_suspend_thread(Thread* thread);
486
487 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
488 static frame fetch_frame_from_context(const void* ucVoid);
489 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
490
491 static void breakpoint();
492 static bool start_debugging(char *buf, int buflen);
493
494 static address current_stack_pointer();
495 static address current_stack_base();
496 static size_t current_stack_size();
497
498 static void verify_stack_alignment() PRODUCT_RETURN;
499
500 static bool message_box(const char* title, const char* message);
501 static char* do_you_want_to_debug(const char* message);
502
503 // run cmd in a separate process and return its exit code; or -1 on failures
504 static int fork_and_exec(char *cmd, bool use_vfork_if_available = false);
505
506 // Call ::exit() on all platforms but Windows
507 static void exit(int num);
508
509 // Terminate the VM, but don't exit the process
510 static void shutdown();
511
512 // Terminate with an error. Default is to generate a core file on platforms
513 // that support such things. This calls shutdown() and then aborts.
514 static void abort(bool dump_core, void *siginfo, const void *context);
515 static void abort(bool dump_core = true);
516
517 // Die immediately, no exit hook, no abort hook, no cleanup.
518 static void die();
519
520 // File i/o operations
521 static const int default_file_open_flags();
522 static int open(const char *path, int oflag, int mode);
523 static FILE* open(int fd, const char* mode);
524 static FILE* fopen(const char* path, const char* mode);
525 static int close(int fd);
526 static jlong lseek(int fd, jlong offset, int whence);
527 // This function, on Windows, canonicalizes a given path (see os_windows.cpp for details).
528 // On Posix, this function is a noop: it does not change anything and just returns
529 // the input pointer.
530 static char* native_path(char *path);
531 static int ftruncate(int fd, jlong length);
532 static int fsync(int fd);
533 static int available(int fd, jlong *bytes);
534 static int get_fileno(FILE* fp);
535 static void flockfile(FILE* fp);
536 static void funlockfile(FILE* fp);
537
538 static int compare_file_modified_times(const char* file1, const char* file2);
539
540 //File i/o operations
541
542 static size_t read(int fd, void *buf, unsigned int nBytes);
543 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
544 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
545 static size_t write(int fd, const void *buf, unsigned int nBytes);
546
547 // Reading directories.
548 static DIR* opendir(const char* dirname);
549 static struct dirent* readdir(DIR* dirp);
550 static int closedir(DIR* dirp);
551
552 // Dynamic library extension
553 static const char* dll_file_extension();
554
555 static const char* get_temp_directory();
556 static const char* get_current_directory(char *buf, size_t buflen);
557
558 // Builds the platform-specific name of a library.
559 // Returns false if the buffer is too small.
560 static bool dll_build_name(char* buffer, size_t size,
561 const char* fname);
562
563 // Builds a platform-specific full library path given an ld path and
564 // unadorned library name. Returns true if the buffer contains a full
565 // path to an existing file, false otherwise. If pathname is empty,
566 // uses the path to the current directory.
567 static bool dll_locate_lib(char* buffer, size_t size,
568 const char* pathname, const char* fname);
569
570 // Symbol lookup, find nearest function name; basically it implements
571 // dladdr() for all platforms. Name of the nearest function is copied
572 // to buf. Distance from its base address is optionally returned as offset.
573 // If function name is not found, buf[0] is set to '\0' and offset is
574 // set to -1 (if offset is non-NULL).
575 static bool dll_address_to_function_name(address addr, char* buf,
576 int buflen, int* offset,
577 bool demangle = true);
578
579 // Locate DLL/DSO. On success, full path of the library is copied to
580 // buf, and offset is optionally set to be the distance between addr
581 // and the library's base address. On failure, buf[0] is set to '\0'
582 // and offset is set to -1 (if offset is non-NULL).
583 static bool dll_address_to_library_name(address addr, char* buf,
584 int buflen, int* offset);
585
586 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
587 static bool address_is_in_vm(address addr);
588
589 // Loads .dll/.so and
590 // in case of error it checks if .dll/.so was built for the
591 // same architecture as HotSpot is running on
592 static void* dll_load(const char *name, char *ebuf, int ebuflen);
593
594 // lookup symbol in a shared library
595 static void* dll_lookup(void* handle, const char* name);
596
597 // Unload library
598 static void dll_unload(void *lib);
599
600 // Callback for loaded module information
601 // Input parameters:
602 // char* module_file_name,
603 // address module_base_addr,
604 // address module_top_addr,
605 // void* param
606 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
607
608 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
609
610 // Return the handle of this process
611 static void* get_default_process_handle();
612
613 // Check for static linked agent library
614 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
615 size_t syms_len);
616
617 // Find agent entry point
618 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
619 const char *syms[], size_t syms_len);
620
621 // Provide C99 compliant versions of these functions, since some versions
622 // of some platforms don't.
623 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
624 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
625
626 // Get host name in buffer provided
627 static bool get_host_name(char* buf, size_t buflen);
628
629 // Print out system information; they are called by fatal error handler.
630 // Output format may be different on different platforms.
631 static void print_os_info(outputStream* st);
632 static void print_os_info_brief(outputStream* st);
633 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
634 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
635 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
636 static void print_memory_info(outputStream* st);
637 static void print_dll_info(outputStream* st);
638 static void print_environment_variables(outputStream* st, const char** env_list);
639 static void print_context(outputStream* st, const void* context);
640 static void print_register_info(outputStream* st, const void* context);
641 static void print_siginfo(outputStream* st, const void* siginfo);
642 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
643 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
644
645 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
646 static size_t lasterror(char *buf, size_t len);
647 static int get_last_error();
648
649 // Replacement for strerror().
650 // Will return the english description of the error (e.g. "File not found", as
651 // suggested in the POSIX standard.
652 // Will return "Unknown error" for an unknown errno value.
653 // Will not attempt to localize the returned string.
654 // Will always return a valid string which is a static constant.
655 // Will not change the value of errno.
656 static const char* strerror(int e);
657
658 // Will return the literalized version of the given errno (e.g. "EINVAL"
659 // for EINVAL).
660 // Will return "Unknown error" for an unknown errno value.
661 // Will always return a valid string which is a static constant.
662 // Will not change the value of errno.
663 static const char* errno_name(int e);
664
665 // Determines whether the calling process is being debugged by a user-mode debugger.
666 static bool is_debugger_attached();
667
668 // wait for a key press if PauseAtExit is set
669 static void wait_for_keypress_at_exit(void);
670
671 // The following two functions are used by fatal error handler to trace
672 // native (C) frames. They are not part of frame.hpp/frame.cpp because
673 // frame.hpp/cpp assume thread is JavaThread, and also because different
674 // OS/compiler may have different convention or provide different API to
675 // walk C frames.
676 //
677 // We don't attempt to become a debugger, so we only follow frames if that
678 // does not require a lookup in the unwind table, which is part of the binary
679 // file but may be unsafe to read after a fatal error. So on x86, we can
680 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
681 // possible to walk C stack without having the unwind table.
682 static bool is_first_C_frame(frame *fr);
683 static frame get_sender_for_C_frame(frame *fr);
684
685 // return current frame. pc() and sp() are set to NULL on failure.
686 static frame current_frame();
687
688 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
689
690 // returns a string to describe the exception/signal;
691 // returns NULL if exception_code is not an OS exception/signal.
692 static const char* exception_name(int exception_code, char* buf, size_t buflen);
693
694 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
695 static int get_signal_number(const char* signal_name);
696
697 // Returns native Java library, loads if necessary
698 static void* native_java_library();
699
700 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
701 static void jvm_path(char *buf, jint buflen);
702
703 // JNI names
704 static void print_jni_name_prefix_on(outputStream* st, int args_size);
705 static void print_jni_name_suffix_on(outputStream* st, int args_size);
706
707 // Init os specific system properties values
708 static void init_system_properties_values();
709
710 // IO operations, non-JVM_ version.
711 static int stat(const char* path, struct stat* sbuf);
712 static bool dir_is_empty(const char* path);
713
714 // IO operations on binary files
715 static int create_binary_file(const char* path, bool rewrite_existing);
716 static jlong current_file_offset(int fd);
717 static jlong seek_to_file_offset(int fd, jlong offset);
718
719 // Retrieve native stack frames.
720 // Parameter:
721 // stack: an array to storage stack pointers.
722 // frames: size of above array.
723 // toSkip: number of stack frames to skip at the beginning.
724 // Return: number of stack frames captured.
725 static int get_native_stack(address* stack, int size, int toSkip = 0);
726
727 // General allocation (must be MT-safe)
728 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
729 static void* malloc (size_t size, MEMFLAGS flags);
730 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
731 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
732
733 static void free (void *memblock);
734 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
735 // Like strdup, but exit VM when strdup() returns NULL
736 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
737
738 #ifndef PRODUCT
739 static julong num_mallocs; // # of calls to malloc/realloc
740 static julong alloc_bytes; // # of bytes allocated
741 static julong num_frees; // # of calls to free
742 static julong free_bytes; // # of bytes freed
743 #endif
744
745 // SocketInterface (ex HPI SocketInterface )
746 static int socket(int domain, int type, int protocol);
747 static int socket_close(int fd);
748 static int recv(int fd, char* buf, size_t nBytes, uint flags);
749 static int send(int fd, char* buf, size_t nBytes, uint flags);
750 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
751 static int connect(int fd, struct sockaddr* him, socklen_t len);
752 static struct hostent* get_host_by_name(char* name);
753
754 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
755 static void initialize_jdk_signal_support(TRAPS);
756 static void signal_notify(int signal_number);
757 static void* signal(int signal_number, void* handler);
758 static void signal_raise(int signal_number);
759 static int signal_wait();
760 static void* user_handler();
761 static void terminate_signal_thread();
762 static int sigexitnum_pd();
763
764 // random number generation
765 static int random(); // return 32bit pseudorandom number
766 static void init_random(unsigned int initval); // initialize random sequence
767
768 // Structured OS Exception support
769 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
770
771 // On Posix compatible OS it will simply check core dump limits while on Windows
772 // it will check if dump file can be created. Check or prepare a core dump to be
773 // taken at a later point in the same thread in os::abort(). Use the caller
774 // provided buffer as a scratch buffer. The status message which will be written
775 // into the error log either is file location or a short error message, depending
776 // on the checking result.
777 static void check_dump_limit(char* buffer, size_t bufferSize);
778
779 // Get the default path to the core file
780 // Returns the length of the string
781 static int get_core_path(char* buffer, size_t bufferSize);
782
783 // JVMTI & JVM monitoring and management support
784 // The thread_cpu_time() and current_thread_cpu_time() are only
785 // supported if is_thread_cpu_time_supported() returns true.
786 // They are not supported on Solaris T1.
787
788 // Thread CPU Time - return the fast estimate on a platform
789 // On Solaris - call gethrvtime (fast) - user time only
790 // On Linux - fast clock_gettime where available - user+sys
791 // - otherwise: very slow /proc fs - user+sys
792 // On Windows - GetThreadTimes - user+sys
793 static jlong current_thread_cpu_time();
794 static jlong thread_cpu_time(Thread* t);
795
796 // Thread CPU Time with user_sys_cpu_time parameter.
797 //
798 // If user_sys_cpu_time is true, user+sys time is returned.
799 // Otherwise, only user time is returned
800 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
801 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
802
803 // Return a bunch of info about the timers.
804 // Note that the returned info for these two functions may be different
805 // on some platforms
806 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
807 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
808
809 static bool is_thread_cpu_time_supported();
810
811 // System loadavg support. Returns -1 if load average cannot be obtained.
812 static int loadavg(double loadavg[], int nelem);
813
814 // Amount beyond the callee frame size that we bang the stack.
815 static int extra_bang_size_in_bytes();
816
817 static char** split_path(const char* path, int* n);
818
819 // Extensions
820 #include "runtime/os_ext.hpp"
821
822 public:
823 class CrashProtectionCallback : public StackObj {
824 public:
825 virtual void call() = 0;
826 };
827
828 // Platform dependent stuff
829 #ifndef _WINDOWS
830 # include "os_posix.hpp"
831 #endif
832 #include OS_CPU_HEADER(os)
833 #include OS_HEADER(os)
834
835 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
836 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
837 #endif
838
839 public:
840 #ifndef PLATFORM_PRINT_NATIVE_STACK
841 // No platform-specific code for printing the native stack.
842 static bool platform_print_native_stack(outputStream* st, const void* context,
843 char *buf, int buf_size) {
844 return false;
845 }
846 #endif
847
848 // debugging support (mostly used by debug.cpp but also fatal error handler)
849 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
850
851 static bool dont_yield(); // when true, JVM_Yield() is nop
852 static void print_statistics();
853
854 // Thread priority helpers (implemented in OS-specific part)
855 static OSReturn set_native_priority(Thread* thread, int native_prio);
856 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
857 static int java_to_os_priority[CriticalPriority + 1];
858 // Hint to the underlying OS that a task switch would not be good.
859 // Void return because it's a hint and can fail.
860 static const char* native_thread_creation_failed_msg() {
861 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
862 }
863
864 // Used at creation if requested by the diagnostic flag PauseAtStartup.
865 // Causes the VM to wait until an external stimulus has been applied
866 // (for Unix, that stimulus is a signal, for Windows, an external
867 // ResumeThread call)
868 static void pause();
869
870 // Builds a platform dependent Agent_OnLoad_<libname> function name
871 // which is used to find statically linked in agents.
872 static char* build_agent_function_name(const char *sym, const char *cname,
873 bool is_absolute_path);
874
875 class SuspendedThreadTaskContext {
876 public:
877 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
878 Thread* thread() const { return _thread; }
879 void* ucontext() const { return _ucontext; }
880 private:
881 Thread* _thread;
882 void* _ucontext;
883 };
884
885 class SuspendedThreadTask {
886 public:
887 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
888 void run();
889 bool is_done() { return _done; }
890 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
891 protected:
892 ~SuspendedThreadTask() {}
893 private:
894 void internal_do_task();
895 Thread* _thread;
896 bool _done;
897 };
898
899 #ifndef _WINDOWS
900 // Suspend/resume support
901 // Protocol:
902 //
903 // a thread starts in SR_RUNNING
904 //
905 // SR_RUNNING can go to
906 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
907 // SR_SUSPEND_REQUEST can go to
908 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
909 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
910 // SR_SUSPENDED can go to
911 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
912 // SR_WAKEUP_REQUEST can go to
913 // * SR_RUNNING when the stopped thread receives the signal
914 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
915 class SuspendResume {
916 public:
917 enum State {
918 SR_RUNNING,
919 SR_SUSPEND_REQUEST,
920 SR_SUSPENDED,
921 SR_WAKEUP_REQUEST
922 };
923
924 private:
925 volatile State _state;
926
927 private:
928 /* try to switch state from state "from" to state "to"
929 * returns the state set after the method is complete
930 */
931 State switch_state(State from, State to);
932
933 public:
934 SuspendResume() : _state(SR_RUNNING) { }
935
936 State state() const { return _state; }
937
938 State request_suspend() {
939 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
940 }
941
942 State cancel_suspend() {
943 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
944 }
945
946 State suspended() {
947 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
948 }
949
950 State request_wakeup() {
951 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
952 }
953
954 State running() {
955 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
956 }
957
958 bool is_running() const {
959 return _state == SR_RUNNING;
960 }
961
962 bool is_suspend_request() const {
963 return _state == SR_SUSPEND_REQUEST;
964 }
965
966 bool is_suspended() const {
967 return _state == SR_SUSPENDED;
968 }
969 };
970 #endif // !WINDOWS
971
972
973 protected:
974 static volatile unsigned int _rand_seed; // seed for random number generator
975 static int _processor_count; // number of processors
976 static int _initial_active_processor_count; // number of active processors during initialization.
977
978 static char* format_boot_path(const char* format_string,
979 const char* home,
980 int home_len,
981 char fileSep,
982 char pathSep);
983 static bool set_boot_path(char fileSep, char pathSep);
984
985 };
986
987 #ifndef _WINDOWS
988 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {};
989 #endif // !_WINDOWS
990
991 // Note that "PAUSE" is almost always used with synchronization
992 // so arguably we should provide Atomic::SpinPause() instead
993 // of the global SpinPause() with C linkage.
994 // It'd also be eligible for inlining on many platforms.
995
996 extern "C" int SpinPause();
997
998 #endif // SHARE_VM_RUNTIME_OS_HPP