1 /*
2 * Copyright (c) 1997, 2019, 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_RUNTIME_OS_HPP
26 #define SHARE_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 NativeCallStack;
55 class methodHandle;
56 class OSThread;
57 class Mutex;
58
59 template<class E> class GrowableArray;
60
61 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
62
63 // Platform-independent error return values from OS functions
64 enum OSReturn {
65 OS_OK = 0, // Operation was successful
66 OS_ERR = -1, // Operation failed
67 OS_INTRPT = -2, // Operation was interrupted
68 OS_TIMEOUT = -3, // Operation timed out
69 OS_NOMEM = -5, // Operation failed for lack of memory
70 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
71 };
72
73 enum ThreadPriority { // JLS 20.20.1-3
74 NoPriority = -1, // Initial non-priority value
75 MinPriority = 1, // Minimum priority
76 NormPriority = 5, // Normal (non-daemon) priority
77 NearMaxPriority = 9, // High priority, used for VMThread
78 MaxPriority = 10, // Highest priority, used for WatcherThread
79 // ensures that VMThread doesn't starve profiler
80 CriticalPriority = 11 // Critical thread priority
81 };
82
83 // Executable parameter flag for os::commit_memory() and
84 // os::commit_memory_or_exit().
85 const bool ExecMem = true;
86
87 // Typedef for structured exception handling support
88 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
89
90 class MallocTracker;
91
92 class os: AllStatic {
93 friend class VMStructs;
94 friend class JVMCIVMStructs;
95 friend class MallocTracker;
96
97 #ifdef ASSERT
98 private:
99 static bool _mutex_init_done;
100 public:
101 static void set_mutex_init_done() { _mutex_init_done = true; }
102 static bool mutex_init_done() { return _mutex_init_done; }
103 #endif
104
105 public:
106 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
107
108 private:
109 static OSThread* _starting_thread;
110 static address _polling_page;
111 public:
112 static size_t _page_sizes[page_sizes_max];
113
114 private:
115 static void init_page_sizes(size_t default_page_size) {
116 _page_sizes[0] = default_page_size;
117 _page_sizes[1] = 0; // sentinel
118 }
119
120 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
121 size_t alignment_hint = 0);
122 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
123 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc);
124 static void pd_split_reserved_memory(char *base, size_t size,
125 size_t split, bool realloc);
126 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
127 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
128 bool executable);
129 // Same as pd_commit_memory() that either succeeds or calls
130 // vm_exit_out_of_memory() with the specified mesg.
131 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
132 bool executable, const char* mesg);
133 static void pd_commit_memory_or_exit(char* addr, size_t size,
134 size_t alignment_hint,
135 bool executable, const char* mesg);
136 static bool pd_uncommit_memory(char* addr, size_t bytes);
137 static bool pd_release_memory(char* addr, size_t bytes);
138
139 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
140 char *addr, size_t bytes, bool read_only = false,
141 bool allow_exec = false);
142 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
143 char *addr, size_t bytes, bool read_only,
144 bool allow_exec);
145 static bool pd_unmap_memory(char *addr, size_t bytes);
146 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
147 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
148
149 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
150
151 // Get summary strings for system information in buffer provided
152 static void get_summary_cpu_info(char* buf, size_t buflen);
153 static void get_summary_os_info(char* buf, size_t buflen);
154
155 static void initialize_initial_active_processor_count();
156
157 LINUX_ONLY(static void pd_init_container_support();)
158
159 public:
160 static void init(void); // Called before command line parsing
161
162 static void init_container_support() { // Called during command line parsing.
163 LINUX_ONLY(pd_init_container_support();)
164 }
165
166 static void init_before_ergo(void); // Called after command line parsing
167 // before VM ergonomics processing.
168 static jint init_2(void); // Called after command line parsing
169 // and VM ergonomics processing
170
171 // unset environment variable
172 static bool unsetenv(const char* name);
173
174 static bool have_special_privileges();
175
176 static jlong javaTimeMillis();
177 static jlong javaTimeNanos();
178 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
179 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
180 static void run_periodic_checks();
181 static bool supports_monotonic_clock();
182
183 // Returns the elapsed time in seconds since the vm started.
184 static double elapsedTime();
185
186 // Returns real time in seconds since an arbitrary point
187 // in the past.
188 static bool getTimesSecs(double* process_real_time,
189 double* process_user_time,
190 double* process_system_time);
191
192 // Interface to the performance counter
193 static jlong elapsed_counter();
194 static jlong elapsed_frequency();
195
196 // The "virtual time" of a thread is the amount of time a thread has
197 // actually run. The first function indicates whether the OS supports
198 // this functionality for the current thread, and if so:
199 // * the second enables vtime tracking (if that is required).
200 // * the third tells whether vtime is enabled.
201 // * the fourth returns the elapsed virtual time for the current
202 // thread.
203 static bool supports_vtime();
204 static bool enable_vtime();
205 static bool vtime_enabled();
206 static double elapsedVTime();
207
208 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
209 // It is MT safe, but not async-safe, as reading time zone
210 // information may require a lock on some platforms.
211 static char* local_time_string(char *buf, size_t buflen);
212 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
213 static struct tm* gmtime_pd (const time_t* clock, struct tm* res);
214 // Fill in buffer with current local time as an ISO-8601 string.
215 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
216 // Returns buffer, or NULL if it failed.
217 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false);
218
219 // Interface for detecting multiprocessor system
220 static inline bool is_MP() {
221 // During bootstrap if _processor_count is not yet initialized
222 // we claim to be MP as that is safest. If any platform has a
223 // stub generator that might be triggered in this phase and for
224 // which being declared MP when in fact not, is a problem - then
225 // the bootstrap routine for the stub generator needs to check
226 // the processor count directly and leave the bootstrap routine
227 // in place until called after initialization has ocurred.
228 return (_processor_count != 1);
229 }
230
231 static julong available_memory();
232 static julong physical_memory();
233 static bool has_allocatable_memory_limit(julong* limit);
234 static bool is_server_class_machine();
235
236 // Returns the id of the processor on which the calling thread is currently executing.
237 // The returned value is guaranteed to be between 0 and (os::processor_count() - 1).
238 static uint processor_id();
239
240 // number of CPUs
241 static int processor_count() {
242 return _processor_count;
243 }
244 static void set_processor_count(int count) { _processor_count = count; }
245
246 // Returns the number of CPUs this process is currently allowed to run on.
247 // Note that on some OSes this can change dynamically.
248 static int active_processor_count();
249
250 // At startup the number of active CPUs this process is allowed to run on.
251 // This value does not change dynamically. May be different from active_processor_count().
252 static int initial_active_processor_count() {
253 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
254 return _initial_active_processor_count;
255 }
256
257 // Bind processes to processors.
258 // This is a two step procedure:
259 // first you generate a distribution of processes to processors,
260 // then you bind processes according to that distribution.
261 // Compute a distribution for number of processes to processors.
262 // Stores the processor id's into the distribution array argument.
263 // Returns true if it worked, false if it didn't.
264 static bool distribute_processes(uint length, uint* distribution);
265 // Binds the current process to a processor.
266 // Returns true if it worked, false if it didn't.
267 static bool bind_to_processor(uint processor_id);
268
269 // Give a name to the current thread.
270 static void set_native_thread_name(const char *name);
271
272 // Interface for stack banging (predetect possible stack overflow for
273 // exception processing) There are guard pages, and above that shadow
274 // pages for stack overflow checking.
275 static bool uses_stack_guard_pages();
276 static bool must_commit_stack_guard_pages();
277 static void map_stack_shadow_pages(address sp);
278 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
279
280 // Find committed memory region within specified range (start, start + size),
281 // return true if found any
282 static bool committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size);
283
284 // OS interface to Virtual Memory
285
286 // Return the default page size.
287 static int vm_page_size();
288
289 // Returns the page size to use for a region of memory.
290 // region_size / min_pages will always be greater than or equal to the
291 // returned value. The returned value will divide region_size.
292 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
293
294 // Returns the page size to use for a region of memory.
295 // region_size / min_pages will always be greater than or equal to the
296 // returned value. The returned value might not divide region_size.
297 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
298
299 // Return the largest page size that can be used
300 static size_t max_page_size() {
301 // The _page_sizes array is sorted in descending order.
302 return _page_sizes[0];
303 }
304
305 // Return a lower bound for page sizes. Also works before os::init completed.
306 static size_t min_page_size() { return 4 * K; }
307
308 // Methods for tracing page sizes returned by the above method.
309 // The region_{min,max}_size parameters should be the values
310 // passed to page_size_for_region() and page_size should be the result of that
311 // call. The (optional) base and size parameters should come from the
312 // ReservedSpace base() and size() methods.
313 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
314 static void trace_page_sizes(const char* str,
315 const size_t region_min_size,
316 const size_t region_max_size,
317 const size_t page_size,
318 const char* base,
319 const size_t size);
320 static void trace_page_sizes_for_requested_size(const char* str,
321 const size_t requested_size,
322 const size_t page_size,
323 const size_t alignment,
324 const char* base,
325 const size_t size);
326
327 static int vm_allocation_granularity();
328 static char* reserve_memory(size_t bytes, char* addr = 0,
329 size_t alignment_hint = 0, int file_desc = -1);
330 static char* reserve_memory(size_t bytes, char* addr,
331 size_t alignment_hint, MEMFLAGS flags);
332 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1);
333 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1);
334 static void split_reserved_memory(char *base, size_t size,
335 size_t split, bool realloc);
336 static bool commit_memory(char* addr, size_t bytes, bool executable);
337 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
338 bool executable);
339 // Same as commit_memory() that either succeeds or calls
340 // vm_exit_out_of_memory() with the specified mesg.
341 static void commit_memory_or_exit(char* addr, size_t bytes,
342 bool executable, const char* mesg);
343 static void commit_memory_or_exit(char* addr, size_t size,
344 size_t alignment_hint,
345 bool executable, const char* mesg);
346 static bool uncommit_memory(char* addr, size_t bytes);
347 static bool release_memory(char* addr, size_t bytes);
348
349 // Touch memory pages that cover the memory range from start to end (exclusive)
350 // to make the OS back the memory range with actual memory.
351 // Current implementation may not touch the last page if unaligned addresses
352 // are passed.
353 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
354
355 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
356 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
357 bool is_committed = true);
358
359 static bool guard_memory(char* addr, size_t bytes);
360 static bool unguard_memory(char* addr, size_t bytes);
361 static bool create_stack_guard_pages(char* addr, size_t bytes);
362 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
363 static bool remove_stack_guard_pages(char* addr, size_t bytes);
364 // Helper function to create a new file with template jvmheap.XXXXXX.
365 // Returns a valid fd on success or else returns -1
366 static int create_file_for_heap(const char* dir);
367 // Map memory to the file referred by fd. This function is slightly different from map_memory()
368 // and is added to be used for implementation of -XX:AllocateHeapAt
369 static char* map_memory_to_file(char* base, size_t size, int fd);
370 // Replace existing reserved memory with file mapping
371 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd);
372
373 static char* map_memory(int fd, const char* file_name, size_t file_offset,
374 char *addr, size_t bytes, bool read_only = false,
375 bool allow_exec = false);
376 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
377 char *addr, size_t bytes, bool read_only,
378 bool allow_exec);
379 static bool unmap_memory(char *addr, size_t bytes);
380 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
381 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
382
383 // NUMA-specific interface
384 static bool numa_has_static_binding();
385 static bool numa_has_group_homing();
386 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
387 static void numa_make_global(char *addr, size_t bytes);
388 static size_t numa_get_groups_num();
389 static size_t numa_get_leaf_groups(int *ids, size_t size);
390 static bool numa_topology_changed();
391 static int numa_get_group_id();
392
393 // Page manipulation
394 struct page_info {
395 size_t size;
396 int lgrp_id;
397 };
398 static bool get_page_info(char *start, page_info* info);
399 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
400
401 static char* non_memory_address_word();
402 // reserve, commit and pin the entire memory region
403 static char* reserve_memory_special(size_t size, size_t alignment,
404 char* addr, bool executable);
405 static bool release_memory_special(char* addr, size_t bytes);
406 static void large_page_init();
407 static size_t large_page_size();
408 static bool can_commit_large_page_memory();
409 static bool can_execute_large_page_memory();
410
411 // OS interface to polling page
412 static address get_polling_page() { return _polling_page; }
413 static void set_polling_page(address page) { _polling_page = page; }
414 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
415 static void make_polling_page_unreadable();
416 static void make_polling_page_readable();
417
418 // Check if pointer points to readable memory (by 4-byte read access)
419 static bool is_readable_pointer(const void* p);
420 static bool is_readable_range(const void* from, const void* to);
421
422 // threads
423
424 enum ThreadType {
425 vm_thread,
426 cgc_thread, // Concurrent GC thread
427 pgc_thread, // Parallel GC thread
428 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads.
429 compiler_thread,
430 watcher_thread,
431 os_thread
432 };
433
434 static bool create_thread(Thread* thread,
435 ThreadType thr_type,
436 size_t req_stack_size = 0);
437
438 // The "main thread", also known as "starting thread", is the thread
439 // that loads/creates the JVM via JNI_CreateJavaVM.
440 static bool create_main_thread(JavaThread* thread);
441
442 // The primordial thread is the initial process thread. The java
443 // launcher never uses the primordial thread as the main thread, but
444 // applications that host the JVM directly may do so. Some platforms
445 // need special-case handling of the primordial thread if it attaches
446 // to the VM.
447 static bool is_primordial_thread(void)
448 #if defined(_WINDOWS) || defined(BSD)
449 // No way to identify the primordial thread.
450 { return false; }
451 #else
452 ;
453 #endif
454
455 static bool create_attached_thread(JavaThread* thread);
456 static void pd_start_thread(Thread* thread);
457 static void start_thread(Thread* thread);
458
459 // Returns true if successful.
460 static bool signal_thread(Thread* thread, int sig, const char* reason);
461
462 static void free_thread(OSThread* osthread);
463
464 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
465 static intx current_thread_id();
466 static int current_process_id();
467 // Implementation of java.lang.Thread.sleep for JavaThreads
468 static int sleep(JavaThread* thread, jlong ms);
469 // Short standalone OS sleep routines suitable for slow path spin loop.
470 // Ignores safepoints/suspension/Thread.interrupt() (so keep it short).
471 // ms/ns = 0, will sleep for the least amount of time allowed by the OS.
472 // Maximum sleep time is just under 1 second.
473 static void naked_short_sleep(jlong ms);
474 static void naked_short_nanosleep(jlong ns);
475 // Longer standalone OS sleep routine - a convenience wrapper around
476 // multiple calls to naked_short_sleep. Only for use by non-JavaThreads.
477 static void naked_sleep(jlong millis);
478 // Never returns, use with CAUTION
479 static void infinite_sleep();
480 static void naked_yield () ;
481 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
482 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
483
484 static void interrupt(Thread* thread);
485 static bool is_interrupted(Thread* thread, bool clear_interrupted);
486
487 static int pd_self_suspend_thread(Thread* thread);
488
489 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
490 static frame fetch_frame_from_context(const void* ucVoid);
491 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
492
493 static void breakpoint();
494 static bool start_debugging(char *buf, int buflen);
495
496 static address current_stack_pointer();
497 static address current_stack_base();
498 static size_t current_stack_size();
499
500 static void verify_stack_alignment() PRODUCT_RETURN;
501
502 static bool message_box(const char* title, const char* message);
503 static char* do_you_want_to_debug(const char* message);
504
505 // run cmd in a separate process and return its exit code; or -1 on failures
506 static int fork_and_exec(char *cmd, bool use_vfork_if_available = false);
507
508 // Call ::exit() on all platforms but Windows
509 static void exit(int num);
510
511 // Terminate the VM, but don't exit the process
512 static void shutdown();
513
514 // Terminate with an error. Default is to generate a core file on platforms
515 // that support such things. This calls shutdown() and then aborts.
516 static void abort(bool dump_core, void *siginfo, const void *context);
517 static void abort(bool dump_core = true);
518
519 // Die immediately, no exit hook, no abort hook, no cleanup.
520 // Dump a core file, if possible, for debugging. os::abort() is the
521 // preferred means to abort the VM on error. os::die() should only
522 // be called if something has gone badly wrong. CreateCoredumpOnCrash
523 // is intentionally not honored by this function.
524 static void die();
525
526 // File i/o operations
527 static const int default_file_open_flags();
528 static int open(const char *path, int oflag, int mode);
529 static FILE* open(int fd, const char* mode);
530 static FILE* fopen(const char* path, const char* mode);
531 static int close(int fd);
532 static jlong lseek(int fd, jlong offset, int whence);
533 // This function, on Windows, canonicalizes a given path (see os_windows.cpp for details).
534 // On Posix, this function is a noop: it does not change anything and just returns
535 // the input pointer.
536 static char* native_path(char *path);
537 static int ftruncate(int fd, jlong length);
538 static int fsync(int fd);
539 static int available(int fd, jlong *bytes);
540 static int get_fileno(FILE* fp);
541 static void flockfile(FILE* fp);
542 static void funlockfile(FILE* fp);
543
544 static int compare_file_modified_times(const char* file1, const char* file2);
545
546 static bool same_files(const char* file1, const char* file2);
547
548 //File i/o operations
549
550 static ssize_t read(int fd, void *buf, unsigned int nBytes);
551 static ssize_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
552 static size_t write(int fd, const void *buf, unsigned int nBytes);
553
554 // Reading directories.
555 static DIR* opendir(const char* dirname);
556 static struct dirent* readdir(DIR* dirp);
557 static int closedir(DIR* dirp);
558
559 // Dynamic library extension
560 static const char* dll_file_extension();
561
562 static const char* get_temp_directory();
563 static const char* get_current_directory(char *buf, size_t buflen);
564
565 // Builds the platform-specific name of a library.
566 // Returns false if the buffer is too small.
567 static bool dll_build_name(char* buffer, size_t size,
568 const char* fname);
569
570 // Builds a platform-specific full library path given an ld path and
571 // unadorned library name. Returns true if the buffer contains a full
572 // path to an existing file, false otherwise. If pathname is empty,
573 // uses the path to the current directory.
574 static bool dll_locate_lib(char* buffer, size_t size,
575 const char* pathname, const char* fname);
576
577 // Symbol lookup, find nearest function name; basically it implements
578 // dladdr() for all platforms. Name of the nearest function is copied
579 // to buf. Distance from its base address is optionally returned as offset.
580 // If function name is not found, buf[0] is set to '\0' and offset is
581 // set to -1 (if offset is non-NULL).
582 static bool dll_address_to_function_name(address addr, char* buf,
583 int buflen, int* offset,
584 bool demangle = true);
585
586 // Locate DLL/DSO. On success, full path of the library is copied to
587 // buf, and offset is optionally set to be the distance between addr
588 // and the library's base address. On failure, buf[0] is set to '\0'
589 // and offset is set to -1 (if offset is non-NULL).
590 static bool dll_address_to_library_name(address addr, char* buf,
591 int buflen, int* offset);
592
593 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
594 static bool address_is_in_vm(address addr);
595
596 // Loads .dll/.so and
597 // in case of error it checks if .dll/.so was built for the
598 // same architecture as HotSpot is running on
599 // in case of an error NULL is returned and an error message is stored in ebuf
600 static void* dll_load(const char *name, char *ebuf, int ebuflen);
601
602 // lookup symbol in a shared library
603 static void* dll_lookup(void* handle, const char* name);
604
605 // Unload library
606 static void dll_unload(void *lib);
607
608 // Callback for loaded module information
609 // Input parameters:
610 // char* module_file_name,
611 // address module_base_addr,
612 // address module_top_addr,
613 // void* param
614 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
615
616 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
617
618 // Return the handle of this process
619 static void* get_default_process_handle();
620
621 // Check for static linked agent library
622 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
623 size_t syms_len);
624
625 // Find agent entry point
626 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
627 const char *syms[], size_t syms_len);
628
629 // Provide C99 compliant versions of these functions, since some versions
630 // of some platforms don't.
631 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
632 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
633
634 // Get host name in buffer provided
635 static bool get_host_name(char* buf, size_t buflen);
636
637 // Print out system information; they are called by fatal error handler.
638 // Output format may be different on different platforms.
639 static void print_os_info(outputStream* st);
640 static void print_os_info_brief(outputStream* st);
641 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
642 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
643 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
644 static void print_memory_info(outputStream* st);
645 static void print_dll_info(outputStream* st);
646 static void print_environment_variables(outputStream* st, const char** env_list);
647 static void print_context(outputStream* st, const void* context);
648 static void print_register_info(outputStream* st, const void* context);
649 static bool signal_sent_by_kill(const void* siginfo);
650 static void print_siginfo(outputStream* st, const void* siginfo);
651 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
652 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
653 static void print_instructions(outputStream* st, address pc, int unitsize);
654
655 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
656 static size_t lasterror(char *buf, size_t len);
657 static int get_last_error();
658
659 // Replacement for strerror().
660 // Will return the english description of the error (e.g. "File not found", as
661 // suggested in the POSIX standard.
662 // Will return "Unknown error" for an unknown errno value.
663 // Will not attempt to localize the returned string.
664 // Will always return a valid string which is a static constant.
665 // Will not change the value of errno.
666 static const char* strerror(int e);
667
668 // Will return the literalized version of the given errno (e.g. "EINVAL"
669 // for EINVAL).
670 // Will return "Unknown error" for an unknown errno value.
671 // Will always return a valid string which is a static constant.
672 // Will not change the value of errno.
673 static const char* errno_name(int e);
674
675 // Determines whether the calling process is being debugged by a user-mode debugger.
676 static bool is_debugger_attached();
677
678 // wait for a key press if PauseAtExit is set
679 static void wait_for_keypress_at_exit(void);
680
681 // The following two functions are used by fatal error handler to trace
682 // native (C) frames. They are not part of frame.hpp/frame.cpp because
683 // frame.hpp/cpp assume thread is JavaThread, and also because different
684 // OS/compiler may have different convention or provide different API to
685 // walk C frames.
686 //
687 // We don't attempt to become a debugger, so we only follow frames if that
688 // does not require a lookup in the unwind table, which is part of the binary
689 // file but may be unsafe to read after a fatal error. So on x86, we can
690 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
691 // possible to walk C stack without having the unwind table.
692 static bool is_first_C_frame(frame *fr);
693 static frame get_sender_for_C_frame(frame *fr);
694
695 // return current frame. pc() and sp() are set to NULL on failure.
696 static frame current_frame();
697
698 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
699
700 // returns a string to describe the exception/signal;
701 // returns NULL if exception_code is not an OS exception/signal.
702 static const char* exception_name(int exception_code, char* buf, size_t buflen);
703
704 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
705 static int get_signal_number(const char* signal_name);
706
707 // Returns native Java library, loads if necessary
708 static void* native_java_library();
709
710 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
711 static void jvm_path(char *buf, jint buflen);
712
713 // JNI names
714 static void print_jni_name_prefix_on(outputStream* st, int args_size);
715 static void print_jni_name_suffix_on(outputStream* st, int args_size);
716
717 // Init os specific system properties values
718 static void init_system_properties_values();
719
720 // IO operations, non-JVM_ version.
721 static int stat(const char* path, struct stat* sbuf);
722 static bool dir_is_empty(const char* path);
723
724 // IO operations on binary files
725 static int create_binary_file(const char* path, bool rewrite_existing);
726 static jlong current_file_offset(int fd);
727 static jlong seek_to_file_offset(int fd, jlong offset);
728
729 // Retrieve native stack frames.
730 // Parameter:
731 // stack: an array to storage stack pointers.
732 // frames: size of above array.
733 // toSkip: number of stack frames to skip at the beginning.
734 // Return: number of stack frames captured.
735 static int get_native_stack(address* stack, int size, int toSkip = 0);
736
737 // General allocation (must be MT-safe)
738 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
739 static void* malloc (size_t size, MEMFLAGS flags);
740 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
741 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
742
743 static void free (void *memblock);
744 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
745 // Like strdup, but exit VM when strdup() returns NULL
746 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
747
748 #ifndef PRODUCT
749 static julong num_mallocs; // # of calls to malloc/realloc
750 static julong alloc_bytes; // # of bytes allocated
751 static julong num_frees; // # of calls to free
752 static julong free_bytes; // # of bytes freed
753 #endif
754
755 // SocketInterface (ex HPI SocketInterface )
756 static int socket(int domain, int type, int protocol);
757 static int socket_close(int fd);
758 static int recv(int fd, char* buf, size_t nBytes, uint flags);
759 static int send(int fd, char* buf, size_t nBytes, uint flags);
760 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
761 static int connect(int fd, struct sockaddr* him, socklen_t len);
762 static struct hostent* get_host_by_name(char* name);
763
764 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
765 static void initialize_jdk_signal_support(TRAPS);
766 static void signal_notify(int signal_number);
767 static void* signal(int signal_number, void* handler);
768 static void signal_raise(int signal_number);
769 static int signal_wait();
770 static void* user_handler();
771 static void terminate_signal_thread();
772 static int sigexitnum_pd();
773
774 // random number generation
775 static int random(); // return 32bit pseudorandom number
776 static void init_random(unsigned int initval); // initialize random sequence
777
778 // Structured OS Exception support
779 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
780
781 // On Posix compatible OS it will simply check core dump limits while on Windows
782 // it will check if dump file can be created. Check or prepare a core dump to be
783 // taken at a later point in the same thread in os::abort(). Use the caller
784 // provided buffer as a scratch buffer. The status message which will be written
785 // into the error log either is file location or a short error message, depending
786 // on the checking result.
787 static void check_dump_limit(char* buffer, size_t bufferSize);
788
789 // Get the default path to the core file
790 // Returns the length of the string
791 static int get_core_path(char* buffer, size_t bufferSize);
792
793 // JVMTI & JVM monitoring and management support
794 // The thread_cpu_time() and current_thread_cpu_time() are only
795 // supported if is_thread_cpu_time_supported() returns true.
796 // They are not supported on Solaris T1.
797
798 // Thread CPU Time - return the fast estimate on a platform
799 // On Solaris - call gethrvtime (fast) - user time only
800 // On Linux - fast clock_gettime where available - user+sys
801 // - otherwise: very slow /proc fs - user+sys
802 // On Windows - GetThreadTimes - user+sys
803 static jlong current_thread_cpu_time();
804 static jlong thread_cpu_time(Thread* t);
805
806 // Thread CPU Time with user_sys_cpu_time parameter.
807 //
808 // If user_sys_cpu_time is true, user+sys time is returned.
809 // Otherwise, only user time is returned
810 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
811 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
812
813 // Return a bunch of info about the timers.
814 // Note that the returned info for these two functions may be different
815 // on some platforms
816 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
817 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
818
819 static bool is_thread_cpu_time_supported();
820
821 // System loadavg support. Returns -1 if load average cannot be obtained.
822 static int loadavg(double loadavg[], int nelem);
823
824 // Amount beyond the callee frame size that we bang the stack.
825 static int extra_bang_size_in_bytes();
826
827 static char** split_path(const char* path, size_t* elements, size_t file_name_length);
828
829 // support for mapping non-volatile memory using MAP_SYNC
830 static bool supports_map_sync();
831
832 public:
833 class CrashProtectionCallback : public StackObj {
834 public:
835 virtual void call() = 0;
836 };
837
838 // Platform dependent stuff
839 #ifndef _WINDOWS
840 # include "os_posix.hpp"
841 #endif
842 #include OS_CPU_HEADER(os)
843 #include OS_HEADER(os)
844
845 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
846 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
847 #endif
848
849 public:
850 #ifndef PLATFORM_PRINT_NATIVE_STACK
851 // No platform-specific code for printing the native stack.
852 static bool platform_print_native_stack(outputStream* st, const void* context,
853 char *buf, int buf_size) {
854 return false;
855 }
856 #endif
857
858 // debugging support (mostly used by debug.cpp but also fatal error handler)
859 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
860
861 static bool dont_yield(); // when true, JVM_Yield() is nop
862 static void print_statistics();
863
864 // Thread priority helpers (implemented in OS-specific part)
865 static OSReturn set_native_priority(Thread* thread, int native_prio);
866 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
867 static int java_to_os_priority[CriticalPriority + 1];
868 // Hint to the underlying OS that a task switch would not be good.
869 // Void return because it's a hint and can fail.
870 static const char* native_thread_creation_failed_msg() {
871 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
872 }
873
874 // Used at creation if requested by the diagnostic flag PauseAtStartup.
875 // Causes the VM to wait until an external stimulus has been applied
876 // (for Unix, that stimulus is a signal, for Windows, an external
877 // ResumeThread call)
878 static void pause();
879
880 // Builds a platform dependent Agent_OnLoad_<libname> function name
881 // which is used to find statically linked in agents.
882 static char* build_agent_function_name(const char *sym, const char *cname,
883 bool is_absolute_path);
884
885 class SuspendedThreadTaskContext {
886 public:
887 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
888 Thread* thread() const { return _thread; }
889 void* ucontext() const { return _ucontext; }
890 private:
891 Thread* _thread;
892 void* _ucontext;
893 };
894
895 class SuspendedThreadTask {
896 public:
897 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
898 void run();
899 bool is_done() { return _done; }
900 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
901 protected:
902 ~SuspendedThreadTask() {}
903 private:
904 void internal_do_task();
905 Thread* _thread;
906 bool _done;
907 };
908
909 #ifndef _WINDOWS
910 // Suspend/resume support
911 // Protocol:
912 //
913 // a thread starts in SR_RUNNING
914 //
915 // SR_RUNNING can go to
916 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
917 // SR_SUSPEND_REQUEST can go to
918 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
919 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
920 // SR_SUSPENDED can go to
921 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
922 // SR_WAKEUP_REQUEST can go to
923 // * SR_RUNNING when the stopped thread receives the signal
924 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
925 class SuspendResume {
926 public:
927 enum State {
928 SR_RUNNING,
929 SR_SUSPEND_REQUEST,
930 SR_SUSPENDED,
931 SR_WAKEUP_REQUEST
932 };
933
934 private:
935 volatile State _state;
936
937 private:
938 /* try to switch state from state "from" to state "to"
939 * returns the state set after the method is complete
940 */
941 State switch_state(State from, State to);
942
943 public:
944 SuspendResume() : _state(SR_RUNNING) { }
945
946 State state() const { return _state; }
947
948 State request_suspend() {
949 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
950 }
951
952 State cancel_suspend() {
953 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
954 }
955
956 State suspended() {
957 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
958 }
959
960 State request_wakeup() {
961 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
962 }
963
964 State running() {
965 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
966 }
967
968 bool is_running() const {
969 return _state == SR_RUNNING;
970 }
971
972 bool is_suspend_request() const {
973 return _state == SR_SUSPEND_REQUEST;
974 }
975
976 bool is_suspended() const {
977 return _state == SR_SUSPENDED;
978 }
979 };
980 #endif // !WINDOWS
981
982
983 protected:
984 static volatile unsigned int _rand_seed; // seed for random number generator
985 static int _processor_count; // number of processors
986 static int _initial_active_processor_count; // number of active processors during initialization.
987
988 static char* format_boot_path(const char* format_string,
989 const char* home,
990 int home_len,
991 char fileSep,
992 char pathSep);
993 static bool set_boot_path(char fileSep, char pathSep);
994
995 };
996
997 #ifndef _WINDOWS
998 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {};
999 #endif // !_WINDOWS
1000
1001 // Note that "PAUSE" is almost always used with synchronization
1002 // so arguably we should provide Atomic::SpinPause() instead
1003 // of the global SpinPause() with C linkage.
1004 // It'd also be eligible for inlining on many platforms.
1005
1006 extern "C" int SpinPause();
1007
1008 #endif // SHARE_RUNTIME_OS_HPP