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