1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_OS_HPP
26 #define SHARE_VM_RUNTIME_OS_HPP
27
28 #include "jvm.h"
29 #include "jvmtifiles/jvmti.h"
30 #include "metaprogramming/isRegisteredEnum.hpp"
31 #include "metaprogramming/integralConstant.hpp"
32 #include "runtime/extendedPC.hpp"
33 #include "utilities/exceptions.hpp"
34 #include "utilities/ostream.hpp"
35 #include "utilities/macros.hpp"
36 #ifndef _WINDOWS
37 # include <setjmp.h>
38 #endif
39 #ifdef __APPLE__
40 # include <mach/mach_time.h>
41 #endif
42
43 class AgentLibrary;
44 class frame;
45
46 // os defines the interface to operating system; this includes traditional
47 // OS services (time, I/O) as well as other functionality with system-
48 // dependent code.
49
50 typedef void (*dll_func)(...);
51
52 class Thread;
53 class JavaThread;
54 class Event;
55 class DLL;
56 class FileHandle;
57 class NativeCallStack;
58 class methodHandle;
59
60 template<class E> class GrowableArray;
61
62 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
63
64 // Platform-independent error return values from OS functions
65 enum OSReturn {
66 OS_OK = 0, // Operation was successful
67 OS_ERR = -1, // Operation failed
68 OS_INTRPT = -2, // Operation was interrupted
69 OS_TIMEOUT = -3, // Operation timed out
70 OS_NOMEM = -5, // Operation failed for lack of memory
71 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
72 };
73
74 enum ThreadPriority { // JLS 20.20.1-3
75 NoPriority = -1, // Initial non-priority value
76 MinPriority = 1, // Minimum priority
77 NormPriority = 5, // Normal (non-daemon) priority
78 NearMaxPriority = 9, // High priority, used for VMThread
79 MaxPriority = 10, // Highest priority, used for WatcherThread
80 // ensures that VMThread doesn't starve profiler
81 CriticalPriority = 11 // Critical thread priority
82 };
83
84 // Executable parameter flag for os::commit_memory() and
85 // os::commit_memory_or_exit().
86 const bool ExecMem = true;
87
88 // Typedef for structured exception handling support
89 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
90
91 class MallocTracker;
92
93 class os: AllStatic {
94 friend class VMStructs;
95 friend class JVMCIVMStructs;
96 friend class MallocTracker;
97 public:
98 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
99
100 private:
101 static OSThread* _starting_thread;
102 static address _polling_page;
103 static volatile int32_t * _mem_serialize_page;
104 static uintptr_t _serialize_page_mask;
105 public:
106 static size_t _page_sizes[page_sizes_max];
107
108 private:
109 static void init_page_sizes(size_t default_page_size) {
110 _page_sizes[0] = default_page_size;
111 _page_sizes[1] = 0; // sentinel
112 }
113
114 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
115 size_t alignment_hint = 0);
116 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
117 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc);
118 static void pd_split_reserved_memory(char *base, size_t size,
119 size_t split, bool realloc);
120 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
121 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
122 bool executable);
123 // Same as pd_commit_memory() that either succeeds or calls
124 // vm_exit_out_of_memory() with the specified mesg.
125 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
126 bool executable, const char* mesg);
127 static void pd_commit_memory_or_exit(char* addr, size_t size,
128 size_t alignment_hint,
129 bool executable, const char* mesg);
130 static bool pd_uncommit_memory(char* addr, size_t bytes);
131 static bool pd_release_memory(char* addr, size_t bytes);
132
133 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
134 char *addr, size_t bytes, bool read_only = false,
135 bool allow_exec = false);
136 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
137 char *addr, size_t bytes, bool read_only,
138 bool allow_exec);
139 static bool pd_unmap_memory(char *addr, size_t bytes);
140 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
141 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
142
143 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
144
145 // Get summary strings for system information in buffer provided
146 static void get_summary_cpu_info(char* buf, size_t buflen);
147 static void get_summary_os_info(char* buf, size_t buflen);
148
149 static void initialize_initial_active_processor_count();
150
151 LINUX_ONLY(static void pd_init_container_support();)
152
153 public:
154 static void init(void); // Called before command line parsing
155
156 static void init_container_support() { // Called during command line parsing.
157 LINUX_ONLY(pd_init_container_support();)
158 }
159
160 static void init_before_ergo(void); // Called after command line parsing
161 // before VM ergonomics processing.
162 static jint init_2(void); // Called after command line parsing
163 // and VM ergonomics processing
164 static void init_globals(void) { // Called from init_globals() in init.cpp
165 init_globals_ext();
166 }
167
168 // File names are case-insensitive on windows only
169 // Override me as needed
170 static int file_name_strncmp(const char* s1, const char* s2, size_t num);
171
172 // unset environment variable
173 static bool unsetenv(const char* name);
174
175 static bool have_special_privileges();
176
177 static jlong javaTimeMillis();
178 static jlong javaTimeNanos();
179 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
180 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
181 static void run_periodic_checks();
182 static bool supports_monotonic_clock();
183
184 // Returns the elapsed time in seconds since the vm started.
185 static double elapsedTime();
186
187 // Returns real time in seconds since an arbitrary point
188 // in the past.
189 static bool getTimesSecs(double* process_real_time,
190 double* process_user_time,
191 double* process_system_time);
192
193 // Interface to the performance counter
194 static jlong elapsed_counter();
195 static jlong elapsed_frequency();
196
197 // The "virtual time" of a thread is the amount of time a thread has
198 // actually run. The first function indicates whether the OS supports
199 // this functionality for the current thread, and if so:
200 // * the second enables vtime tracking (if that is required).
201 // * the third tells whether vtime is enabled.
202 // * the fourth returns the elapsed virtual time for the current
203 // thread.
204 static bool supports_vtime();
205 static bool enable_vtime();
206 static bool vtime_enabled();
207 static double elapsedVTime();
208
209 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
210 // It is MT safe, but not async-safe, as reading time zone
211 // information may require a lock on some platforms.
212 static char* local_time_string(char *buf, size_t buflen);
213 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
214 static struct tm* gmtime_pd (const time_t* clock, struct tm* res);
215 // Fill in buffer with current local time as an ISO-8601 string.
216 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
217 // Returns buffer, or NULL if it failed.
218 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false);
219
220 // Interface for detecting multiprocessor system
221 static inline bool is_MP() {
222 // During bootstrap if _processor_count is not yet initialized
223 // we claim to be MP as that is safest. If any platform has a
224 // stub generator that might be triggered in this phase and for
225 // which being declared MP when in fact not, is a problem - then
226 // the bootstrap routine for the stub generator needs to check
227 // the processor count directly and leave the bootstrap routine
228 // in place until called after initialization has ocurred.
229 return AssumeMP || (_processor_count != 1);
230 }
231 static inline bool has_nvdimm() {
232 // This is set AFTER memory is successfully mapped on NVDIMM's
233 // DAX filesystem
234 return _nvdimm_present;
235 }
236 static inline int nvdimm_fd() {
237 // ParallelOldGC adaptive sizing requires nvdimm fd.
238 return _nvdimm_fd;
239 }
240 static inline address dram_heapbase() {
241 return _dram_heap_base;
242 }
243 static inline address nvdimm_heapbase() {
244 return _nvdimm_heap_base;
245 }
246 static inline uint nvdimm_regionlength() {
247 return _nvdimm_region_length;
248 }
249 static julong available_memory();
250 static julong physical_memory();
251 static bool has_allocatable_memory_limit(julong* limit);
252 static bool is_server_class_machine();
253
254 // Returns the id of the processor on which the calling thread is currently executing.
255 // The returned value is guaranteed to be between 0 and (os::processor_count() - 1).
256 static uint processor_id();
257
258 // number of CPUs
259 static int processor_count() {
260 return _processor_count;
261 }
262 static void set_processor_count(int count) { _processor_count = count; }
263
264 static void set_nvdimm_present(bool status) { _nvdimm_present = status; }
265 static void set_nvdimm_fd(int fd) { _nvdimm_fd = fd; }
266 static void set_dram_heapbase(address base) {_dram_heap_base = base; }
267 static void set_nvdimm_heapbase(address base) {_nvdimm_heap_base = base; }
268 static void set_nvdimm_regionlength(uint length) {_nvdimm_region_length = length; }
269
270 // Returns the number of CPUs this process is currently allowed to run on.
271 // Note that on some OSes this can change dynamically.
272 static int active_processor_count();
273
274 // At startup the number of active CPUs this process is allowed to run on.
275 // This value does not change dynamically. May be different from active_processor_count().
276 static int initial_active_processor_count() {
277 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
278 return _initial_active_processor_count;
279 }
280
281 // Bind processes to processors.
282 // This is a two step procedure:
283 // first you generate a distribution of processes to processors,
284 // then you bind processes according to that distribution.
285 // Compute a distribution for number of processes to processors.
286 // Stores the processor id's into the distribution array argument.
287 // Returns true if it worked, false if it didn't.
288 static bool distribute_processes(uint length, uint* distribution);
289 // Binds the current process to a processor.
290 // Returns true if it worked, false if it didn't.
291 static bool bind_to_processor(uint processor_id);
292
293 // Give a name to the current thread.
294 static void set_native_thread_name(const char *name);
295
296 // Interface for stack banging (predetect possible stack overflow for
297 // exception processing) There are guard pages, and above that shadow
298 // pages for stack overflow checking.
299 static bool uses_stack_guard_pages();
300 static bool must_commit_stack_guard_pages();
301 static void map_stack_shadow_pages(address sp);
302 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
303
304 // Find committed memory region within specified range (start, start + size),
305 // return true if found any
306 static bool committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size);
307
308 // OS interface to Virtual Memory
309
310 // Return the default page size.
311 static int vm_page_size();
312
313 // Returns the page size to use for a region of memory.
314 // region_size / min_pages will always be greater than or equal to the
315 // returned value. The returned value will divide region_size.
316 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
317
318 // Returns the page size to use for a region of memory.
319 // region_size / min_pages will always be greater than or equal to the
320 // returned value. The returned value might not divide region_size.
321 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
322
323 // Return the largest page size that can be used
324 static size_t max_page_size() {
325 // The _page_sizes array is sorted in descending order.
326 return _page_sizes[0];
327 }
328
329 // Methods for tracing page sizes returned by the above method.
330 // The region_{min,max}_size parameters should be the values
331 // passed to page_size_for_region() and page_size should be the result of that
332 // call. The (optional) base and size parameters should come from the
333 // ReservedSpace base() and size() methods.
334 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
335 static void trace_page_sizes(const char* str,
336 const size_t region_min_size,
337 const size_t region_max_size,
338 const size_t page_size,
339 const char* base,
340 const size_t size);
341 static void trace_page_sizes_for_requested_size(const char* str,
342 const size_t requested_size,
343 const size_t page_size,
344 const size_t alignment,
345 const char* base,
346 const size_t size);
347
348 static int vm_allocation_granularity();
349 static char* reserve_memory(size_t bytes, char* addr = 0,
350 size_t alignment_hint = 0, int file_desc = -1);
351 static char* reserve_memory(size_t bytes, char* addr,
352 size_t alignment_hint, MEMFLAGS flags);
353 static char* reserve_memory_aligned(size_t size, size_t alignment, int file_desc = -1);
354 static char* attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc = -1);
355 static void split_reserved_memory(char *base, size_t size,
356 size_t split, bool realloc);
357 static bool commit_memory(char* addr, size_t bytes, bool executable);
358 static bool commit_memory(char* addr, size_t bytes, bool executable, int file_desc, size_t offset = 0);
359 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
360 bool executable);
361 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
362 bool executable, int file_desc, size_t offset = 0);
363 // Same as commit_memory() that either succeeds or calls
364 // vm_exit_out_of_memory() with the specified mesg.
365 static void commit_memory_or_exit(char* addr, size_t bytes,
366 bool executable, const char* mesg);
367 static void commit_memory_or_exit(char* addr, size_t size,
368 size_t alignment_hint,
369 bool executable, const char* mesg);
370 static bool uncommit_memory(char* addr, size_t bytes);
371 static bool release_memory(char* addr, size_t bytes);
372
373 // Touch memory pages that cover the memory range from start to end (exclusive)
374 // to make the OS back the memory range with actual memory.
375 // Current implementation may not touch the last page if unaligned addresses
376 // are passed.
377 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
378
379 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
380 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
381 bool is_committed = true);
382
383 static bool guard_memory(char* addr, size_t bytes);
384 static bool unguard_memory(char* addr, size_t bytes);
385 static bool create_stack_guard_pages(char* addr, size_t bytes);
386 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
387 static bool remove_stack_guard_pages(char* addr, size_t bytes);
388 // Helper function to create a new file with template jvmheap.XXXXXX.
389 // Returns a valid fd on success or else returns -1
390 static int create_file_for_heap(const char* dir);
391 // Map memory to the file referred by fd. This function is slightly different from map_memory()
392 // and is added to be used for implementation of -XX:AllocateHeapAt
393 static char* map_memory_to_file(char* base, size_t size, int fd, int offset = 0, bool exec = false, bool allocate = true);
394 static int allocate_file(int file_desc, size_t size);
395 // Replace existing reserved memory with file mapping
396 static char* replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd);
397
398 static char* map_memory(int fd, const char* file_name, size_t file_offset,
399 char *addr, size_t bytes, bool read_only = false,
400 bool allow_exec = false);
401 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
402 char *addr, size_t bytes, bool read_only,
403 bool allow_exec);
404 static bool unmap_memory(char *addr, size_t bytes);
405 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
406 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
407
408 // NUMA-specific interface
409 static bool numa_has_static_binding();
410 static bool numa_has_group_homing();
411 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
412 static void numa_make_global(char *addr, size_t bytes);
413 static size_t numa_get_groups_num();
414 static size_t numa_get_leaf_groups(int *ids, size_t size);
415 static bool numa_topology_changed();
416 static int numa_get_group_id();
417
418 // Page manipulation
419 struct page_info {
420 size_t size;
421 int lgrp_id;
422 };
423 static bool get_page_info(char *start, page_info* info);
424 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
425
426 static char* non_memory_address_word();
427 // reserve, commit and pin the entire memory region
428 static char* reserve_memory_special(size_t size, size_t alignment,
429 char* addr, bool executable);
430 static bool release_memory_special(char* addr, size_t bytes);
431 static void large_page_init();
432 static size_t large_page_size();
433 static bool can_commit_large_page_memory();
434 static bool can_execute_large_page_memory();
435
436 // OS interface to polling page
437 static address get_polling_page() { return _polling_page; }
438 static void set_polling_page(address page) { _polling_page = page; }
439 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
440 static void make_polling_page_unreadable();
441 static void make_polling_page_readable();
442
443 // Routines used to serialize the thread state without using membars
444 static void serialize_thread_states();
445
446 // Since we write to the serialize page from every thread, we
447 // want stores to be on unique cache lines whenever possible
448 // in order to minimize CPU cross talk. We pre-compute the
449 // amount to shift the thread* to make this offset unique to
450 // each thread.
451 static int get_serialize_page_shift_count() {
452 return SerializePageShiftCount;
453 }
454
455 static void set_serialize_page_mask(uintptr_t mask) {
456 _serialize_page_mask = mask;
457 }
458
459 static unsigned int get_serialize_page_mask() {
460 return _serialize_page_mask;
461 }
462
463 static void set_memory_serialize_page(address page);
464
465 static address get_memory_serialize_page() {
466 return (address)_mem_serialize_page;
467 }
468
469 static inline void write_memory_serialize_page(JavaThread *thread) {
470 uintptr_t page_offset = ((uintptr_t)thread >>
471 get_serialize_page_shift_count()) &
472 get_serialize_page_mask();
473 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
474 }
475
476 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
477 if (UseMembar) return false;
478 // Previously this function calculated the exact address of this
479 // thread's serialize page, and checked if the faulting address
480 // was equal. However, some platforms mask off faulting addresses
481 // to the page size, so now we just check that the address is
482 // within the page. This makes the thread argument unnecessary,
483 // but we retain the NULL check to preserve existing behavior.
484 if (thread == NULL) return false;
485 address page = (address) _mem_serialize_page;
486 return addr >= page && addr < (page + os::vm_page_size());
487 }
488
489 static void block_on_serialize_page_trap();
490
491 // threads
492
493 enum ThreadType {
494 vm_thread,
495 cgc_thread, // Concurrent GC thread
496 pgc_thread, // Parallel GC thread
497 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads.
498 compiler_thread,
499 watcher_thread,
500 os_thread
501 };
502
503 static bool create_thread(Thread* thread,
504 ThreadType thr_type,
505 size_t req_stack_size = 0);
506
507 // The "main thread", also known as "starting thread", is the thread
508 // that loads/creates the JVM via JNI_CreateJavaVM.
509 static bool create_main_thread(JavaThread* thread);
510
511 // The primordial thread is the initial process thread. The java
512 // launcher never uses the primordial thread as the main thread, but
513 // applications that host the JVM directly may do so. Some platforms
514 // need special-case handling of the primordial thread if it attaches
515 // to the VM.
516 static bool is_primordial_thread(void)
517 #if defined(_WINDOWS) || defined(BSD)
518 // No way to identify the primordial thread.
519 { return false; }
520 #else
521 ;
522 #endif
523
524 static bool create_attached_thread(JavaThread* thread);
525 static void pd_start_thread(Thread* thread);
526 static void start_thread(Thread* thread);
527
528 static void initialize_thread(Thread* thr);
529 static void free_thread(OSThread* osthread);
530
531 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
532 static intx current_thread_id();
533 static int current_process_id();
534 static int sleep(Thread* thread, jlong ms, bool interruptable);
535 // Short standalone OS sleep suitable for slow path spin loop.
536 // Ignores Thread.interrupt() (so keep it short).
537 // ms = 0, will sleep for the least amount of time allowed by the OS.
538 static void naked_short_sleep(jlong ms);
539 static void infinite_sleep(); // never returns, use with CAUTION
540 static void naked_yield () ;
541 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
542 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
543
544 static void interrupt(Thread* thread);
545 static bool is_interrupted(Thread* thread, bool clear_interrupted);
546
547 static int pd_self_suspend_thread(Thread* thread);
548
549 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
550 static frame fetch_frame_from_context(const void* ucVoid);
551 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
552
553 static void breakpoint();
554 static bool start_debugging(char *buf, int buflen);
555
556 static address current_stack_pointer();
557 static address current_stack_base();
558 static size_t current_stack_size();
559
560 static void verify_stack_alignment() PRODUCT_RETURN;
561
562 static bool message_box(const char* title, const char* message);
563 static char* do_you_want_to_debug(const char* message);
564
565 // run cmd in a separate process and return its exit code; or -1 on failures
566 static int fork_and_exec(char *cmd);
567
568 // Call ::exit() on all platforms but Windows
569 static void exit(int num);
570
571 // Terminate the VM, but don't exit the process
572 static void shutdown();
573
574 // Terminate with an error. Default is to generate a core file on platforms
575 // that support such things. This calls shutdown() and then aborts.
576 static void abort(bool dump_core, void *siginfo, const void *context);
577 static void abort(bool dump_core = true);
578
579 // Die immediately, no exit hook, no abort hook, no cleanup.
580 static void die();
581
582 // File i/o operations
583 static const int default_file_open_flags();
584 static int open(const char *path, int oflag, int mode);
585 static FILE* open(int fd, const char* mode);
586 static FILE* fopen(const char* path, const char* mode);
587 static int close(int fd);
588 static jlong lseek(int fd, jlong offset, int whence);
589 static char* native_path(char *path);
590 static int ftruncate(int fd, jlong length);
591 static int fsync(int fd);
592 static int available(int fd, jlong *bytes);
593 static int get_fileno(FILE* fp);
594 static void flockfile(FILE* fp);
595 static void funlockfile(FILE* fp);
596
597 static int compare_file_modified_times(const char* file1, const char* file2);
598
599 //File i/o operations
600
601 static size_t read(int fd, void *buf, unsigned int nBytes);
602 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
603 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
604 static size_t write(int fd, const void *buf, unsigned int nBytes);
605
606 // Reading directories.
607 static DIR* opendir(const char* dirname);
608 static int readdir_buf_size(const char *path);
609 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
610 static int closedir(DIR* dirp);
611
612 // Dynamic library extension
613 static const char* dll_file_extension();
614
615 static const char* get_temp_directory();
616 static const char* get_current_directory(char *buf, size_t buflen);
617
618 // Builds the platform-specific name of a library.
619 // Returns false if the buffer is too small.
620 static bool dll_build_name(char* buffer, size_t size,
621 const char* fname);
622
623 // Builds a platform-specific full library path given an ld path and
624 // unadorned library name. Returns true if the buffer contains a full
625 // path to an existing file, false otherwise. If pathname is empty,
626 // uses the path to the current directory.
627 static bool dll_locate_lib(char* buffer, size_t size,
628 const char* pathname, const char* fname);
629
630 // Symbol lookup, find nearest function name; basically it implements
631 // dladdr() for all platforms. Name of the nearest function is copied
632 // to buf. Distance from its base address is optionally returned as offset.
633 // If function name is not found, buf[0] is set to '\0' and offset is
634 // set to -1 (if offset is non-NULL).
635 static bool dll_address_to_function_name(address addr, char* buf,
636 int buflen, int* offset,
637 bool demangle = true);
638
639 // Locate DLL/DSO. On success, full path of the library is copied to
640 // buf, and offset is optionally set to be the distance between addr
641 // and the library's base address. On failure, buf[0] is set to '\0'
642 // and offset is set to -1 (if offset is non-NULL).
643 static bool dll_address_to_library_name(address addr, char* buf,
644 int buflen, int* offset);
645
646 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
647 static bool address_is_in_vm(address addr);
648
649 // Loads .dll/.so and
650 // in case of error it checks if .dll/.so was built for the
651 // same architecture as HotSpot is running on
652 static void* dll_load(const char *name, char *ebuf, int ebuflen);
653
654 // lookup symbol in a shared library
655 static void* dll_lookup(void* handle, const char* name);
656
657 // Unload library
658 static void dll_unload(void *lib);
659
660 // Callback for loaded module information
661 // Input parameters:
662 // char* module_file_name,
663 // address module_base_addr,
664 // address module_top_addr,
665 // void* param
666 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
667
668 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
669
670 // Return the handle of this process
671 static void* get_default_process_handle();
672
673 // Check for static linked agent library
674 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
675 size_t syms_len);
676
677 // Find agent entry point
678 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
679 const char *syms[], size_t syms_len);
680
681 // Provide C99 compliant versions of these functions, since some versions
682 // of some platforms don't.
683 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
684 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
685
686 // Get host name in buffer provided
687 static bool get_host_name(char* buf, size_t buflen);
688
689 // Print out system information; they are called by fatal error handler.
690 // Output format may be different on different platforms.
691 static void print_os_info(outputStream* st);
692 static void print_os_info_brief(outputStream* st);
693 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
694 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
695 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
696 static void print_memory_info(outputStream* st);
697 static void print_dll_info(outputStream* st);
698 static void print_environment_variables(outputStream* st, const char** env_list);
699 static void print_context(outputStream* st, const void* context);
700 static void print_register_info(outputStream* st, const void* context);
701 static void print_siginfo(outputStream* st, const void* siginfo);
702 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
703 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
704
705 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
706 static size_t lasterror(char *buf, size_t len);
707 static int get_last_error();
708
709 // Replacement for strerror().
710 // Will return the english description of the error (e.g. "File not found", as
711 // suggested in the POSIX standard.
712 // Will return "Unknown error" for an unknown errno value.
713 // Will not attempt to localize the returned string.
714 // Will always return a valid string which is a static constant.
715 // Will not change the value of errno.
716 static const char* strerror(int e);
717
718 // Will return the literalized version of the given errno (e.g. "EINVAL"
719 // for EINVAL).
720 // Will return "Unknown error" for an unknown errno value.
721 // Will always return a valid string which is a static constant.
722 // Will not change the value of errno.
723 static const char* errno_name(int e);
724
725 // Determines whether the calling process is being debugged by a user-mode debugger.
726 static bool is_debugger_attached();
727
728 // wait for a key press if PauseAtExit is set
729 static void wait_for_keypress_at_exit(void);
730
731 // The following two functions are used by fatal error handler to trace
732 // native (C) frames. They are not part of frame.hpp/frame.cpp because
733 // frame.hpp/cpp assume thread is JavaThread, and also because different
734 // OS/compiler may have different convention or provide different API to
735 // walk C frames.
736 //
737 // We don't attempt to become a debugger, so we only follow frames if that
738 // does not require a lookup in the unwind table, which is part of the binary
739 // file but may be unsafe to read after a fatal error. So on x86, we can
740 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
741 // possible to walk C stack without having the unwind table.
742 static bool is_first_C_frame(frame *fr);
743 static frame get_sender_for_C_frame(frame *fr);
744
745 // return current frame. pc() and sp() are set to NULL on failure.
746 static frame current_frame();
747
748 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
749
750 // returns a string to describe the exception/signal;
751 // returns NULL if exception_code is not an OS exception/signal.
752 static const char* exception_name(int exception_code, char* buf, size_t buflen);
753
754 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
755 static int get_signal_number(const char* signal_name);
756
757 // Returns native Java library, loads if necessary
758 static void* native_java_library();
759
760 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
761 static void jvm_path(char *buf, jint buflen);
762
763 // JNI names
764 static void print_jni_name_prefix_on(outputStream* st, int args_size);
765 static void print_jni_name_suffix_on(outputStream* st, int args_size);
766
767 // Init os specific system properties values
768 static void init_system_properties_values();
769
770 // IO operations, non-JVM_ version.
771 static int stat(const char* path, struct stat* sbuf);
772 static bool dir_is_empty(const char* path);
773
774 // IO operations on binary files
775 static int create_binary_file(const char* path, bool rewrite_existing);
776 static jlong current_file_offset(int fd);
777 static jlong seek_to_file_offset(int fd, jlong offset);
778
779 // Retrieve native stack frames.
780 // Parameter:
781 // stack: an array to storage stack pointers.
782 // frames: size of above array.
783 // toSkip: number of stack frames to skip at the beginning.
784 // Return: number of stack frames captured.
785 static int get_native_stack(address* stack, int size, int toSkip = 0);
786
787 // General allocation (must be MT-safe)
788 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
789 static void* malloc (size_t size, MEMFLAGS flags);
790 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
791 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
792
793 static void free (void *memblock);
794 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
795 // Like strdup, but exit VM when strdup() returns NULL
796 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
797
798 #ifndef PRODUCT
799 static julong num_mallocs; // # of calls to malloc/realloc
800 static julong alloc_bytes; // # of bytes allocated
801 static julong num_frees; // # of calls to free
802 static julong free_bytes; // # of bytes freed
803 #endif
804
805 // SocketInterface (ex HPI SocketInterface )
806 static int socket(int domain, int type, int protocol);
807 static int socket_close(int fd);
808 static int recv(int fd, char* buf, size_t nBytes, uint flags);
809 static int send(int fd, char* buf, size_t nBytes, uint flags);
810 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
811 static int connect(int fd, struct sockaddr* him, socklen_t len);
812 static struct hostent* get_host_by_name(char* name);
813
814 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
815 static void initialize_jdk_signal_support(TRAPS);
816 static void signal_notify(int signal_number);
817 static void* signal(int signal_number, void* handler);
818 static void signal_raise(int signal_number);
819 static int signal_wait();
820 static void* user_handler();
821 static void terminate_signal_thread();
822 static int sigexitnum_pd();
823
824 // random number generation
825 static int random(); // return 32bit pseudorandom number
826 static void init_random(unsigned int initval); // initialize random sequence
827
828 // Structured OS Exception support
829 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
830
831 // On Posix compatible OS it will simply check core dump limits while on Windows
832 // it will check if dump file can be created. Check or prepare a core dump to be
833 // taken at a later point in the same thread in os::abort(). Use the caller
834 // provided buffer as a scratch buffer. The status message which will be written
835 // into the error log either is file location or a short error message, depending
836 // on the checking result.
837 static void check_dump_limit(char* buffer, size_t bufferSize);
838
839 // Get the default path to the core file
840 // Returns the length of the string
841 static int get_core_path(char* buffer, size_t bufferSize);
842
843 // JVMTI & JVM monitoring and management support
844 // The thread_cpu_time() and current_thread_cpu_time() are only
845 // supported if is_thread_cpu_time_supported() returns true.
846 // They are not supported on Solaris T1.
847
848 // Thread CPU Time - return the fast estimate on a platform
849 // On Solaris - call gethrvtime (fast) - user time only
850 // On Linux - fast clock_gettime where available - user+sys
851 // - otherwise: very slow /proc fs - user+sys
852 // On Windows - GetThreadTimes - user+sys
853 static jlong current_thread_cpu_time();
854 static jlong thread_cpu_time(Thread* t);
855
856 // Thread CPU Time with user_sys_cpu_time parameter.
857 //
858 // If user_sys_cpu_time is true, user+sys time is returned.
859 // Otherwise, only user time is returned
860 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
861 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
862
863 // Return a bunch of info about the timers.
864 // Note that the returned info for these two functions may be different
865 // on some platforms
866 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
867 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
868
869 static bool is_thread_cpu_time_supported();
870
871 // System loadavg support. Returns -1 if load average cannot be obtained.
872 static int loadavg(double loadavg[], int nelem);
873
874 // Hook for os specific jvm options that we don't want to abort on seeing
875 static bool obsolete_option(const JavaVMOption *option);
876
877 // Amount beyond the callee frame size that we bang the stack.
878 static int extra_bang_size_in_bytes();
879
880 static char** split_path(const char* path, int* n);
881
882 // Extensions
883 #include "runtime/os_ext.hpp"
884
885 public:
886 class CrashProtectionCallback : public StackObj {
887 public:
888 virtual void call() = 0;
889 };
890
891 // Platform dependent stuff
892 #ifndef _WINDOWS
893 # include "os_posix.hpp"
894 #endif
895 #include OS_CPU_HEADER(os)
896 #include OS_HEADER(os)
897
898 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
899 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
900 #endif
901
902 public:
903 #ifndef PLATFORM_PRINT_NATIVE_STACK
904 // No platform-specific code for printing the native stack.
905 static bool platform_print_native_stack(outputStream* st, const void* context,
906 char *buf, int buf_size) {
907 return false;
908 }
909 #endif
910
911 // debugging support (mostly used by debug.cpp but also fatal error handler)
912 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
913
914 static bool dont_yield(); // when true, JVM_Yield() is nop
915 static void print_statistics();
916
917 // Thread priority helpers (implemented in OS-specific part)
918 static OSReturn set_native_priority(Thread* thread, int native_prio);
919 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
920 static int java_to_os_priority[CriticalPriority + 1];
921 // Hint to the underlying OS that a task switch would not be good.
922 // Void return because it's a hint and can fail.
923 static void hint_no_preempt();
924 static const char* native_thread_creation_failed_msg() {
925 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
926 }
927
928 // Used at creation if requested by the diagnostic flag PauseAtStartup.
929 // Causes the VM to wait until an external stimulus has been applied
930 // (for Unix, that stimulus is a signal, for Windows, an external
931 // ResumeThread call)
932 static void pause();
933
934 // Builds a platform dependent Agent_OnLoad_<libname> function name
935 // which is used to find statically linked in agents.
936 static char* build_agent_function_name(const char *sym, const char *cname,
937 bool is_absolute_path);
938
939 class SuspendedThreadTaskContext {
940 public:
941 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
942 Thread* thread() const { return _thread; }
943 void* ucontext() const { return _ucontext; }
944 private:
945 Thread* _thread;
946 void* _ucontext;
947 };
948
949 class SuspendedThreadTask {
950 public:
951 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
952 void run();
953 bool is_done() { return _done; }
954 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
955 protected:
956 ~SuspendedThreadTask() {}
957 private:
958 void internal_do_task();
959 Thread* _thread;
960 bool _done;
961 };
962
963 #ifndef _WINDOWS
964 // Suspend/resume support
965 // Protocol:
966 //
967 // a thread starts in SR_RUNNING
968 //
969 // SR_RUNNING can go to
970 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
971 // SR_SUSPEND_REQUEST can go to
972 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
973 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
974 // SR_SUSPENDED can go to
975 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
976 // SR_WAKEUP_REQUEST can go to
977 // * SR_RUNNING when the stopped thread receives the signal
978 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
979 class SuspendResume {
980 public:
981 enum State {
982 SR_RUNNING,
983 SR_SUSPEND_REQUEST,
984 SR_SUSPENDED,
985 SR_WAKEUP_REQUEST
986 };
987
988 private:
989 volatile State _state;
990
991 private:
992 /* try to switch state from state "from" to state "to"
993 * returns the state set after the method is complete
994 */
995 State switch_state(State from, State to);
996
997 public:
998 SuspendResume() : _state(SR_RUNNING) { }
999
1000 State state() const { return _state; }
1001
1002 State request_suspend() {
1003 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
1004 }
1005
1006 State cancel_suspend() {
1007 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
1008 }
1009
1010 State suspended() {
1011 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
1012 }
1013
1014 State request_wakeup() {
1015 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
1016 }
1017
1018 State running() {
1019 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
1020 }
1021
1022 bool is_running() const {
1023 return _state == SR_RUNNING;
1024 }
1025
1026 bool is_suspend_request() const {
1027 return _state == SR_SUSPEND_REQUEST;
1028 }
1029
1030 bool is_suspended() const {
1031 return _state == SR_SUSPENDED;
1032 }
1033 };
1034 #endif // !WINDOWS
1035
1036
1037 protected:
1038 static volatile unsigned int _rand_seed; // seed for random number generator
1039 static int _processor_count; // number of processors
1040 static int _initial_active_processor_count; // number of active processors during initialization.
1041
1042 static char* format_boot_path(const char* format_string,
1043 const char* home,
1044 int home_len,
1045 char fileSep,
1046 char pathSep);
1047 static bool set_boot_path(char fileSep, char pathSep);
1048 static bool _nvdimm_present;
1049 static int _nvdimm_fd;
1050 static address _dram_heap_base;
1051 static address _nvdimm_heap_base;
1052 static uint _nvdimm_region_length;
1053 };
1054
1055 #ifndef _WINDOWS
1056 template<> struct IsRegisteredEnum<os::SuspendResume::State> : public TrueType {};
1057 #endif // !_WINDOWS
1058
1059 // Note that "PAUSE" is almost always used with synchronization
1060 // so arguably we should provide Atomic::SpinPause() instead
1061 // of the global SpinPause() with C linkage.
1062 // It'd also be eligible for inlining on many platforms.
1063
1064 extern "C" int SpinPause();
1065
1066 #endif // SHARE_VM_RUNTIME_OS_HPP