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 static void init_globals(void) { // Called from init_globals() in init.cpp
171 init_globals_ext();
172 }
173
174 // File names are case-insensitive on windows only
175 // Override me as needed
176 static int file_name_strncmp(const char* s1, const char* s2, size_t num);
177
178 // unset environment variable
179 static bool unsetenv(const char* name);
180
181 static bool have_special_privileges();
182
183 static jlong javaTimeMillis();
184 static jlong javaTimeNanos();
185 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
186 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
187 static void run_periodic_checks();
188 static bool supports_monotonic_clock();
189
190 // Returns the elapsed time in seconds since the vm started.
191 static double elapsedTime();
192
193 // Returns real time in seconds since an arbitrary point
194 // in the past.
195 static bool getTimesSecs(double* process_real_time,
196 double* process_user_time,
197 double* process_system_time);
198
199 // Interface to the performance counter
200 static jlong elapsed_counter();
201 static jlong elapsed_frequency();
202
203 // The "virtual time" of a thread is the amount of time a thread has
204 // actually run. The first function indicates whether the OS supports
205 // this functionality for the current thread, and if so:
206 // * the second enables vtime tracking (if that is required).
207 // * the third tells whether vtime is enabled.
208 // * the fourth returns the elapsed virtual time for the current
209 // thread.
210 static bool supports_vtime();
211 static bool enable_vtime();
212 static bool vtime_enabled();
213 static double elapsedVTime();
214
215 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
216 // It is MT safe, but not async-safe, as reading time zone
217 // information may require a lock on some platforms.
218 static char* local_time_string(char *buf, size_t buflen);
219 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
220 static struct tm* gmtime_pd (const time_t* clock, struct tm* res);
221 // Fill in buffer with current local time as an ISO-8601 string.
222 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
223 // Returns buffer, or NULL if it failed.
224 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false);
225
226 // Interface for detecting multiprocessor system
227 static inline bool is_MP() {
228 // During bootstrap if _processor_count is not yet initialized
229 // we claim to be MP as that is safest. If any platform has a
230 // stub generator that might be triggered in this phase and for
231 // which being declared MP when in fact not, is a problem - then
232 // the bootstrap routine for the stub generator needs to check
233 // the processor count directly and leave the bootstrap routine
234 // in place until called after initialization has ocurred.
235 return (_processor_count != 1);
236 }
237
238 static julong available_memory();
239 static julong physical_memory();
240 static bool has_allocatable_memory_limit(julong* limit);
241 static bool is_server_class_machine();
242
243 // Returns the id of the processor on which the calling thread is currently executing.
244 // The returned value is guaranteed to be between 0 and (os::processor_count() - 1).
245 static uint processor_id();
246
247 // number of CPUs
248 static int processor_count() {
249 return _processor_count;
250 }
251 static void set_processor_count(int count) { _processor_count = count; }
252
253 // Returns the number of CPUs this process is currently allowed to run on.
254 // Note that on some OSes this can change dynamically.
255 static int active_processor_count();
256
257 // At startup the number of active CPUs this process is allowed to run on.
258 // This value does not change dynamically. May be different from active_processor_count().
259 static int initial_active_processor_count() {
260 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
261 return _initial_active_processor_count;
262 }
263
264 // Bind processes to processors.
265 // This is a two step procedure:
266 // first you generate a distribution of processes to processors,
267 // then you bind processes according to that distribution.
268 // Compute a distribution for number of processes to processors.
269 // Stores the processor id's into the distribution array argument.
270 // Returns true if it worked, false if it didn't.
271 static bool distribute_processes(uint length, uint* distribution);
272 // Binds the current process to a processor.
273 // Returns true if it worked, false if it didn't.
274 static bool bind_to_processor(uint processor_id);
275
276 // Give a name to the current thread.
277 static void set_native_thread_name(const char *name);
278
279 // Interface for stack banging (predetect possible stack overflow for
280 // exception processing) There are guard pages, and above that shadow
281 // pages for stack overflow checking.
282 static bool uses_stack_guard_pages();
283 static bool must_commit_stack_guard_pages();
284 static void map_stack_shadow_pages(address sp);
285 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
286
287 // Find committed memory region within specified range (start, start + size),
288 // return true if found any
289 static bool committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size);
290
291 // OS interface to Virtual Memory
292
293 // Return the default page size.
294 static int vm_page_size();
295
296 // Returns the page size to use for a region of memory.
297 // region_size / min_pages will always be greater than or equal to the
298 // returned value. The returned value will divide region_size.
299 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
300
301 // Returns the page size to use for a region of memory.
302 // region_size / min_pages will always be greater than or equal to the
303 // returned value. The returned value might not divide region_size.
304 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
305
306 // Return the largest page size that can be used
307 static size_t max_page_size() {
308 // The _page_sizes array is sorted in descending order.
309 return _page_sizes[0];
310 }
311
312 // Return a lower bound for page sizes. Also works before os::init completed.
313 static size_t min_page_size() { return 4 * K; }
314
315 // Methods for tracing page sizes returned by the above method.
316 // The region_{min,max}_size parameters should be the values
317 // passed to page_size_for_region() and page_size should be the result of that
318 // call. The (optional) base and size parameters should come from the
319 // ReservedSpace base() and size() methods.
320 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
321 static void trace_page_sizes(const char* str,
322 const size_t region_min_size,
323 const size_t region_max_size,
324 const size_t page_size,
325 const char* base,
326 const size_t size);
327 static void trace_page_sizes_for_requested_size(const char* str,
328 const size_t requested_size,
329 const size_t page_size,
330 const size_t alignment,
331 const char* base,
332 const size_t size);
333
334 static int vm_allocation_granularity();
335 static char* reserve_memory(size_t bytes, char* addr = 0,
336 size_t alignment_hint = 0, int file_desc = -1);
337 static char* reserve_memory(size_t bytes, char* addr,
338 size_t alignment_hint, MEMFLAGS flags);
339 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1);
340 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1);
341 static void split_reserved_memory(char *base, size_t size,
342 size_t split, bool realloc);
343 static bool commit_memory(char* addr, size_t bytes, bool executable);
344 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
345 bool executable);
346 // Same as commit_memory() that either succeeds or calls
347 // vm_exit_out_of_memory() with the specified mesg.
348 static void commit_memory_or_exit(char* addr, size_t bytes,
349 bool executable, const char* mesg);
350 static void commit_memory_or_exit(char* addr, size_t size,
351 size_t alignment_hint,
352 bool executable, const char* mesg);
353 static bool uncommit_memory(char* addr, size_t bytes);
354 static bool release_memory(char* addr, size_t bytes);
355
356 // Touch memory pages that cover the memory range from start to end (exclusive)
357 // to make the OS back the memory range with actual memory.
358 // Current implementation may not touch the last page if unaligned addresses
359 // are passed.
360 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
361
362 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
363 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
364 bool is_committed = true);
365
366 static bool guard_memory(char* addr, size_t bytes);
367 static bool unguard_memory(char* addr, size_t bytes);
368 static bool create_stack_guard_pages(char* addr, size_t bytes);
369 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
370 static bool remove_stack_guard_pages(char* addr, size_t bytes);
371 // Helper function to create a new file with template jvmheap.XXXXXX.
372 // Returns a valid fd on success or else returns -1
373 static int create_file_for_heap(const char* dir);
374 // Map memory to the file referred by fd. This function is slightly different from map_memory()
375 // and is added to be used for implementation of -XX:AllocateHeapAt
376 static char* map_memory_to_file(char* base, size_t size, int fd);
377 // Replace existing reserved memory with file mapping
378 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd);
379
380 static char* map_memory(int fd, const char* file_name, size_t file_offset,
381 char *addr, size_t bytes, bool read_only = false,
382 bool allow_exec = false);
383 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
384 char *addr, size_t bytes, bool read_only,
385 bool allow_exec);
386 static bool unmap_memory(char *addr, size_t bytes);
387 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
388 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
389
390 // NUMA-specific interface
391 static bool numa_has_static_binding();
392 static bool numa_has_group_homing();
393 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
394 static void numa_make_global(char *addr, size_t bytes);
395 static size_t numa_get_groups_num();
396 static size_t numa_get_leaf_groups(int *ids, size_t size);
397 static bool numa_topology_changed();
398 static int numa_get_group_id();
399
400 // Page manipulation
401 struct page_info {
402 size_t size;
403 int lgrp_id;
404 };
405 static bool get_page_info(char *start, page_info* info);
406 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
407
408 static char* non_memory_address_word();
409 // reserve, commit and pin the entire memory region
410 static char* reserve_memory_special(size_t size, size_t alignment,
411 char* addr, bool executable);
412 static bool release_memory_special(char* addr, size_t bytes);
413 static void large_page_init();
414 static size_t large_page_size();
415 static bool can_commit_large_page_memory();
416 static bool can_execute_large_page_memory();
417
418 // OS interface to polling page
419 static address get_polling_page() { return _polling_page; }
420 static void set_polling_page(address page) { _polling_page = page; }
421 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
422 static void make_polling_page_unreadable();
423 static void make_polling_page_readable();
424
425 // Check if pointer points to readable memory (by 4-byte read access)
426 static bool is_readable_pointer(const void* p);
427 static bool is_readable_range(const void* from, const void* to);
428
429 // threads
430
431 enum ThreadType {
432 vm_thread,
433 cgc_thread, // Concurrent GC thread
434 pgc_thread, // Parallel GC thread
435 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads.
436 compiler_thread,
437 watcher_thread,
438 os_thread
439 };
440
441 static bool create_thread(Thread* thread,
442 ThreadType thr_type,
443 size_t req_stack_size = 0);
444
445 // The "main thread", also known as "starting thread", is the thread
446 // that loads/creates the JVM via JNI_CreateJavaVM.
447 static bool create_main_thread(JavaThread* thread);
448
449 // The primordial thread is the initial process thread. The java
450 // launcher never uses the primordial thread as the main thread, but
451 // applications that host the JVM directly may do so. Some platforms
452 // need special-case handling of the primordial thread if it attaches
453 // to the VM.
454 static bool is_primordial_thread(void)
455 #if defined(_WINDOWS) || defined(BSD)
456 // No way to identify the primordial thread.
457 { return false; }
458 #else
459 ;
460 #endif
461
462 static bool create_attached_thread(JavaThread* thread);
463 static void pd_start_thread(Thread* thread);
464 static void start_thread(Thread* thread);
465
466 // Returns true if successful.
467 static bool signal_thread(Thread* thread, int sig, const char* reason);
468
469 static void free_thread(OSThread* osthread);
470
471 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
472 static intx current_thread_id();
473 static int current_process_id();
474 static int sleep(Thread* thread, jlong ms, bool interruptable);
475 // Short standalone OS sleep suitable for slow path spin loop.
476 // Ignores Thread.interrupt() (so keep it short).
477 // ms = 0, will sleep for the least amount of time allowed by the OS.
478 static void naked_short_sleep(jlong ms);
479 static void naked_short_nanosleep(jlong ns);
480 static void infinite_sleep(); // never returns, use with CAUTION
481 static void naked_yield () ;
482 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
483 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
484
485 static void interrupt(Thread* thread);
486 static bool is_interrupted(Thread* thread, bool clear_interrupted);
487
488 static int pd_self_suspend_thread(Thread* thread);
489
490 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
491 static frame fetch_frame_from_context(const void* ucVoid);
492 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
493
494 static void breakpoint();
495 static bool start_debugging(char *buf, int buflen);
496
497 static address current_stack_pointer();
498 static address current_stack_base();
499 static size_t current_stack_size();
500
501 static void verify_stack_alignment() PRODUCT_RETURN;
502
503 static bool message_box(const char* title, const char* message);
504 static char* do_you_want_to_debug(const char* message);
505
506 // run cmd in a separate process and return its exit code; or -1 on failures
507 static int fork_and_exec(char *cmd, bool use_vfork_if_available = false);
508
509 // Call ::exit() on all platforms but Windows
510 static void exit(int num);
511
512 // Terminate the VM, but don't exit the process
513 static void shutdown();
514
515 // Terminate with an error. Default is to generate a core file on platforms
516 // that support such things. This calls shutdown() and then aborts.
517 static void abort(bool dump_core, void *siginfo, const void *context);
518 static void abort(bool dump_core = true);
519
520 // Die immediately, no exit hook, no abort hook, no cleanup.
521 // Dump a core file, if possible, for debugging. os::abort() is the
522 // preferred means to abort the VM on error. os::die() should only
523 // be called if something has gone badly wrong. CreateCoredumpOnCrash
524 // is intentionally not honored by this function.
525 static void die();
526
527 // File i/o operations
528 static const int default_file_open_flags();
529 static int open(const char *path, int oflag, int mode);
530 static FILE* open(int fd, const char* mode);
531 static FILE* fopen(const char* path, const char* mode);
532 static int close(int fd);
533 static jlong lseek(int fd, jlong offset, int whence);
534 // This function, on Windows, canonicalizes a given path (see os_windows.cpp for details).
535 // On Posix, this function is a noop: it does not change anything and just returns
536 // the input pointer.
537 static char* native_path(char *path);
538 static int ftruncate(int fd, jlong length);
539 static int fsync(int fd);
540 static int available(int fd, jlong *bytes);
541 static int get_fileno(FILE* fp);
542 static void flockfile(FILE* fp);
543 static void funlockfile(FILE* fp);
544
545 static int compare_file_modified_times(const char* file1, const char* file2);
546
547 //File i/o operations
548
549 static ssize_t read(int fd, void *buf, unsigned int nBytes);
550 static ssize_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
551 static size_t write(int fd, const void *buf, unsigned int nBytes);
552
553 // Reading directories.
554 static DIR* opendir(const char* dirname);
555 static struct dirent* readdir(DIR* dirp);
556 static int closedir(DIR* dirp);
557
558 // Dynamic library extension
559 static const char* dll_file_extension();
560
561 static const char* get_temp_directory();
562 static const char* get_current_directory(char *buf, size_t buflen);
563
564 // Builds the platform-specific name of a library.
565 // Returns false if the buffer is too small.
566 static bool dll_build_name(char* buffer, size_t size,
567 const char* fname);
568
569 // Builds a platform-specific full library path given an ld path and
570 // unadorned library name. Returns true if the buffer contains a full
571 // path to an existing file, false otherwise. If pathname is empty,
572 // uses the path to the current directory.
573 static bool dll_locate_lib(char* buffer, size_t size,
574 const char* pathname, const char* fname);
575
576 // Symbol lookup, find nearest function name; basically it implements
577 // dladdr() for all platforms. Name of the nearest function is copied
578 // to buf. Distance from its base address is optionally returned as offset.
579 // If function name is not found, buf[0] is set to '\0' and offset is
580 // set to -1 (if offset is non-NULL).
581 static bool dll_address_to_function_name(address addr, char* buf,
582 int buflen, int* offset,
583 bool demangle = true);
584
585 // Locate DLL/DSO. On success, full path of the library is copied to
586 // buf, and offset is optionally set to be the distance between addr
587 // and the library's base address. On failure, buf[0] is set to '\0'
588 // and offset is set to -1 (if offset is non-NULL).
589 static bool dll_address_to_library_name(address addr, char* buf,
590 int buflen, int* offset);
591
592 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
593 static bool address_is_in_vm(address addr);
594
595 // Loads .dll/.so and
596 // in case of error it checks if .dll/.so was built for the
597 // same architecture as HotSpot is running on
598 // in case of an error NULL is returned and an error message is stored in ebuf
599 static void* dll_load(const char *name, char *ebuf, int ebuflen);
600
601 // lookup symbol in a shared library
602 static void* dll_lookup(void* handle, const char* name);
603
604 // Unload library
605 static void dll_unload(void *lib);
606
607 // Callback for loaded module information
608 // Input parameters:
609 // char* module_file_name,
610 // address module_base_addr,
611 // address module_top_addr,
612 // void* param
613 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
614
615 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
616
617 // Return the handle of this process
618 static void* get_default_process_handle();
619
620 // Check for static linked agent library
621 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
622 size_t syms_len);
623
624 // Find agent entry point
625 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
626 const char *syms[], size_t syms_len);
627
628 // Provide C99 compliant versions of these functions, since some versions
629 // of some platforms don't.
630 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
631 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
632
633 // Get host name in buffer provided
634 static bool get_host_name(char* buf, size_t buflen);
635
636 // Print out system information; they are called by fatal error handler.
637 // Output format may be different on different platforms.
638 static void print_os_info(outputStream* st);
639 static void print_os_info_brief(outputStream* st);
640 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
641 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
642 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
643 static void print_memory_info(outputStream* st);
644 static void print_dll_info(outputStream* st);
645 static void print_environment_variables(outputStream* st, const char** env_list);
646 static void print_context(outputStream* st, const void* context);
647 static void print_register_info(outputStream* st, const void* context);
648 static bool signal_sent_by_kill(const void* siginfo);
649 static void print_siginfo(outputStream* st, const void* siginfo);
650 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
651 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
652 static void print_instructions(outputStream* st, address pc, int unitsize);
653
654 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
655 static size_t lasterror(char *buf, size_t len);
656 static int get_last_error();
657
658 // Replacement for strerror().
659 // Will return the english description of the error (e.g. "File not found", as
660 // suggested in the POSIX standard.
661 // Will return "Unknown error" for an unknown errno value.
662 // Will not attempt to localize the returned string.
663 // Will always return a valid string which is a static constant.
664 // Will not change the value of errno.
665 static const char* strerror(int e);
666
667 // Will return the literalized version of the given errno (e.g. "EINVAL"
668 // for EINVAL).
669 // Will return "Unknown error" for an unknown errno value.
670 // Will always return a valid string which is a static constant.
671 // Will not change the value of errno.
672 static const char* errno_name(int e);
673
674 // Determines whether the calling process is being debugged by a user-mode debugger.
675 static bool is_debugger_attached();
676
677 // wait for a key press if PauseAtExit is set
678 static void wait_for_keypress_at_exit(void);
679
680 // The following two functions are used by fatal error handler to trace
681 // native (C) frames. They are not part of frame.hpp/frame.cpp because
682 // frame.hpp/cpp assume thread is JavaThread, and also because different
683 // OS/compiler may have different convention or provide different API to
684 // walk C frames.
685 //
686 // We don't attempt to become a debugger, so we only follow frames if that
687 // does not require a lookup in the unwind table, which is part of the binary
688 // file but may be unsafe to read after a fatal error. So on x86, we can
689 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
690 // possible to walk C stack without having the unwind table.
691 static bool is_first_C_frame(frame *fr);
692 static frame get_sender_for_C_frame(frame *fr);
693
694 // return current frame. pc() and sp() are set to NULL on failure.
695 static frame current_frame();
696
697 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
698
699 // returns a string to describe the exception/signal;
700 // returns NULL if exception_code is not an OS exception/signal.
701 static const char* exception_name(int exception_code, char* buf, size_t buflen);
702
703 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
704 static int get_signal_number(const char* signal_name);
705
706 // Returns native Java library, loads if necessary
707 static void* native_java_library();
708
709 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
710 static void jvm_path(char *buf, jint buflen);
711
712 // JNI names
713 static void print_jni_name_prefix_on(outputStream* st, int args_size);
714 static void print_jni_name_suffix_on(outputStream* st, int args_size);
715
716 // Init os specific system properties values
717 static void init_system_properties_values();
718
719 // IO operations, non-JVM_ version.
720 static int stat(const char* path, struct stat* sbuf);
721 static bool dir_is_empty(const char* path);
722
723 // IO operations on binary files
724 static int create_binary_file(const char* path, bool rewrite_existing);
725 static jlong current_file_offset(int fd);
726 static jlong seek_to_file_offset(int fd, jlong offset);
727
728 // Retrieve native stack frames.
729 // Parameter:
730 // stack: an array to storage stack pointers.
731 // frames: size of above array.
732 // toSkip: number of stack frames to skip at the beginning.
733 // Return: number of stack frames captured.
734 static int get_native_stack(address* stack, int size, int toSkip = 0);
735
736 // General allocation (must be MT-safe)
737 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
738 static void* malloc (size_t size, MEMFLAGS flags);
739 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
740 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
741
742 static void free (void *memblock);
743 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
744 // Like strdup, but exit VM when strdup() returns NULL
745 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
746
747 #ifndef PRODUCT
748 static julong num_mallocs; // # of calls to malloc/realloc
749 static julong alloc_bytes; // # of bytes allocated
750 static julong num_frees; // # of calls to free
751 static julong free_bytes; // # of bytes freed
752 #endif
753
754 // SocketInterface (ex HPI SocketInterface )
755 static int socket(int domain, int type, int protocol);
756 static int socket_close(int fd);
757 static int recv(int fd, char* buf, size_t nBytes, uint flags);
758 static int send(int fd, char* buf, size_t nBytes, uint flags);
759 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
760 static int connect(int fd, struct sockaddr* him, socklen_t len);
761 static struct hostent* get_host_by_name(char* name);
762
763 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
764 static void initialize_jdk_signal_support(TRAPS);
765 static void signal_notify(int signal_number);
766 static void* signal(int signal_number, void* handler);
767 static void signal_raise(int signal_number);
768 static int signal_wait();
769 static void* user_handler();
770 static void terminate_signal_thread();
771 static int sigexitnum_pd();
772
773 // random number generation
774 static int random(); // return 32bit pseudorandom number
775 static void init_random(unsigned int initval); // initialize random sequence
776
777 // Structured OS Exception support
778 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
779
780 // On Posix compatible OS it will simply check core dump limits while on Windows
781 // it will check if dump file can be created. Check or prepare a core dump to be
782 // taken at a later point in the same thread in os::abort(). Use the caller
783 // provided buffer as a scratch buffer. The status message which will be written
784 // into the error log either is file location or a short error message, depending
785 // on the checking result.
786 static void check_dump_limit(char* buffer, size_t bufferSize);
787
788 // Get the default path to the core file
789 // Returns the length of the string
790 static int get_core_path(char* buffer, size_t bufferSize);
791
792 // JVMTI & JVM monitoring and management support
793 // The thread_cpu_time() and current_thread_cpu_time() are only
794 // supported if is_thread_cpu_time_supported() returns true.
795 // They are not supported on Solaris T1.
796
797 // Thread CPU Time - return the fast estimate on a platform
798 // On Solaris - call gethrvtime (fast) - user time only
799 // On Linux - fast clock_gettime where available - user+sys
800 // - otherwise: very slow /proc fs - user+sys
801 // On Windows - GetThreadTimes - user+sys
802 static jlong current_thread_cpu_time();
803 static jlong thread_cpu_time(Thread* t);
804
805 // Thread CPU Time with user_sys_cpu_time parameter.
806 //
807 // If user_sys_cpu_time is true, user+sys time is returned.
808 // Otherwise, only user time is returned
809 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
810 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
811
812 // Return a bunch of info about the timers.
813 // Note that the returned info for these two functions may be different
814 // on some platforms
815 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
816 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
817
818 static bool is_thread_cpu_time_supported();
819
820 // System loadavg support. Returns -1 if load average cannot be obtained.
821 static int loadavg(double loadavg[], int nelem);
822
823 // Amount beyond the callee frame size that we bang the stack.
824 static int extra_bang_size_in_bytes();
825
826 static char** split_path(const char* path, int* n);
827
828 // Extensions
829 #include "runtime/os_ext.hpp"
830
831 public:
832 class CrashProtectionCallback : public StackObj {
833 public:
834 virtual void call() = 0;
835 };
836
837 // Platform dependent stuff
838 #ifndef _WINDOWS
839 # include "os_posix.hpp"
840 #endif
841 #include OS_CPU_HEADER(os)
842 #include OS_HEADER(os)
843
844 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
845 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
846 #endif
847
848 public:
849 #ifndef PLATFORM_PRINT_NATIVE_STACK
850 // No platform-specific code for printing the native stack.
851 static bool platform_print_native_stack(outputStream* st, const void* context,
852 char *buf, int buf_size) {
853 return false;
854 }
855 #endif
856
857 // debugging support (mostly used by debug.cpp but also fatal error handler)
858 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
859
860 static bool dont_yield(); // when true, JVM_Yield() is nop
861 static void print_statistics();
862
863 // Thread priority helpers (implemented in OS-specific part)
864 static OSReturn set_native_priority(Thread* thread, int native_prio);
865 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
866 static int java_to_os_priority[CriticalPriority + 1];
867 // Hint to the underlying OS that a task switch would not be good.
868 // Void return because it's a hint and can fail.
869 static const char* native_thread_creation_failed_msg() {
870 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
871 }
872
873 // Used at creation if requested by the diagnostic flag PauseAtStartup.
874 // Causes the VM to wait until an external stimulus has been applied
875 // (for Unix, that stimulus is a signal, for Windows, an external
876 // ResumeThread call)
877 static void pause();
878
879 // Builds a platform dependent Agent_OnLoad_<libname> function name
880 // which is used to find statically linked in agents.
881 static char* build_agent_function_name(const char *sym, const char *cname,
882 bool is_absolute_path);
883
884 class SuspendedThreadTaskContext {
885 public:
886 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
887 Thread* thread() const { return _thread; }
888 void* ucontext() const { return _ucontext; }
889 private:
890 Thread* _thread;
891 void* _ucontext;
892 };
893
894 class SuspendedThreadTask {
895 public:
896 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
897 void run();
898 bool is_done() { return _done; }
899 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
900 protected:
901 ~SuspendedThreadTask() {}
902 private:
903 void internal_do_task();
904 Thread* _thread;
905 bool _done;
906 };
907
908 #ifndef _WINDOWS
909 // Suspend/resume support
910 // Protocol:
911 //
912 // a thread starts in SR_RUNNING
913 //
914 // SR_RUNNING can go to
915 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
916 // SR_SUSPEND_REQUEST can go to
917 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
918 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
919 // SR_SUSPENDED can go to
920 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
921 // SR_WAKEUP_REQUEST can go to
922 // * SR_RUNNING when the stopped thread receives the signal
923 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
924 class SuspendResume {
925 public:
926 enum State {
927 SR_RUNNING,
928 SR_SUSPEND_REQUEST,
929 SR_SUSPENDED,
930 SR_WAKEUP_REQUEST
931 };
932
933 private:
934 volatile State _state;
935
936 private:
937 /* try to switch state from state "from" to state "to"
938 * returns the state set after the method is complete
939 */
940 State switch_state(State from, State to);
941
942 public:
943 SuspendResume() : _state(SR_RUNNING) { }
944
945 State state() const { return _state; }
946
947 State request_suspend() {
948 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
949 }
950
951 State cancel_suspend() {
952 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
953 }
954
955 State suspended() {
956 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
957 }
958
959 State request_wakeup() {
960 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
961 }
962
963 State running() {
964 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
965 }
966
967 bool is_running() const {
968 return _state == SR_RUNNING;
969 }
970
971 bool is_suspend_request() const {
972 return _state == SR_SUSPEND_REQUEST;
973 }
974
975 bool is_suspended() const {
976 return _state == SR_SUSPENDED;
977 }
978 };
979 #endif // !WINDOWS
980
981
982 protected:
983 static volatile unsigned int _rand_seed; // seed for random number generator
984 static int _processor_count; // number of processors
985 static int _initial_active_processor_count; // number of active processors during initialization.
986
987 static char* format_boot_path(const char* format_string,
988 const char* home,
989 int home_len,
990 char fileSep,
991 char pathSep);
992 static bool set_boot_path(char fileSep, char pathSep);
993
994 };
995
996 #ifndef _WINDOWS
997 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {};
998 #endif // !_WINDOWS
999
1000 // Note that "PAUSE" is almost always used with synchronization
1001 // so arguably we should provide Atomic::SpinPause() instead
1002 // of the global SpinPause() with C linkage.
1003 // It'd also be eligible for inlining on many platforms.
1004
1005 extern "C" int SpinPause();
1006
1007 #endif // SHARE_RUNTIME_OS_HPP