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_VM_RUNTIME_OS_HPP
26 #define SHARE_VM_RUNTIME_OS_HPP
27
28 #include "jvmtifiles/jvmti.h"
29 #include "runtime/atomic.hpp"
30 #include "runtime/extendedPC.hpp"
31 #include "utilities/top.hpp"
32 #ifdef TARGET_OS_FAMILY_linux
33 # include "jvm_linux.h"
34 # include <setjmp.h>
35 #endif
36 #ifdef TARGET_OS_FAMILY_solaris
37 # include "jvm_solaris.h"
38 # include <setjmp.h>
39 #endif
40 #ifdef TARGET_OS_FAMILY_windows
41 # include "jvm_windows.h"
42 #endif
43 #ifdef TARGET_OS_FAMILY_aix
44 # include "jvm_aix.h"
45 # include <setjmp.h>
46 #endif
47 #ifdef TARGET_OS_FAMILY_bsd
48 # include "jvm_bsd.h"
49 # include <setjmp.h>
50 # ifdef __APPLE__
51 # include <mach/mach_time.h>
52 # endif
53 #endif
54
55 class AgentLibrary;
56 class methodHandle;
57 class instanceKlassHandle;
58
59 // os defines the interface to operating system; this includes traditional
60 // OS services (time, I/O) as well as other functionality with system-
61 // dependent code.
62
63 typedef void (*dll_func)(...);
64
65 class Thread;
66 class JavaThread;
67 class Event;
68 class DLL;
69 class FileHandle;
70 class NativeCallStack;
71
72 template<class E> class GrowableArray;
73
74 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
75
76 // Platform-independent error return values from OS functions
77 enum OSReturn {
78 OS_OK = 0, // Operation was successful
79 OS_ERR = -1, // Operation failed
80 OS_INTRPT = -2, // Operation was interrupted
81 OS_TIMEOUT = -3, // Operation timed out
82 OS_NOMEM = -5, // Operation failed for lack of memory
83 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
84 };
85
86 enum ThreadPriority { // JLS 20.20.1-3
87 NoPriority = -1, // Initial non-priority value
88 MinPriority = 1, // Minimum priority
89 NormPriority = 5, // Normal (non-daemon) priority
90 NearMaxPriority = 9, // High priority, used for VMThread
91 MaxPriority = 10, // Highest priority, used for WatcherThread
92 // ensures that VMThread doesn't starve profiler
93 CriticalPriority = 11 // Critical thread priority
94 };
95
96 // Executable parameter flag for os::commit_memory() and
97 // os::commit_memory_or_exit().
98 const bool ExecMem = true;
99
100 // Typedef for structured exception handling support
101 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
102
103 class MallocTracker;
104
105 class os: AllStatic {
106 friend class VMStructs;
107 friend class MallocTracker;
108 public:
109 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
110
111 private:
112 static OSThread* _starting_thread;
113 static address _polling_page;
114 static volatile int32_t * _mem_serialize_page;
115 static uintptr_t _serialize_page_mask;
116 public:
117 static size_t _page_sizes[page_sizes_max];
118
119 private:
120 static void init_page_sizes(size_t default_page_size) {
121 _page_sizes[0] = default_page_size;
122 _page_sizes[1] = 0; // sentinel
123 }
124
125 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
126 size_t alignment_hint = 0);
127 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
128 static void pd_split_reserved_memory(char *base, size_t size,
129 size_t split, bool realloc);
130 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
131 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
132 bool executable);
133 // Same as pd_commit_memory() that either succeeds or calls
134 // vm_exit_out_of_memory() with the specified mesg.
135 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
136 bool executable, const char* mesg);
137 static void pd_commit_memory_or_exit(char* addr, size_t size,
138 size_t alignment_hint,
139 bool executable, const char* mesg);
140 static bool pd_uncommit_memory(char* addr, size_t bytes);
141 static bool pd_release_memory(char* addr, size_t bytes);
142
143 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
144 char *addr, size_t bytes, bool read_only = false,
145 bool allow_exec = false);
146 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
147 char *addr, size_t bytes, bool read_only,
148 bool allow_exec);
149 static bool pd_unmap_memory(char *addr, size_t bytes);
150 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
151 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
152
153 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
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_strcmp(const char* s1, const char* s2);
177
178 // get/unset environment variable
179 static bool getenv(const char* name, char* buffer, int len);
180 static bool unsetenv(const char* name);
181
182 static bool have_special_privileges();
183
184 static jlong javaTimeMillis();
185 static jlong javaTimeNanos();
186 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
187 static void run_periodic_checks();
188
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 // Fill in buffer with current local time as an ISO-8601 string.
221 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
222 // Returns buffer, or NULL if it failed.
223 static char* iso8601_time(char* buffer, size_t buffer_length);
224
225 // Interface for detecting multiprocessor system
226 static inline bool is_MP() {
227 // During bootstrap if _processor_count is not yet initialized
228 // we claim to be MP as that is safest. If any platform has a
229 // stub generator that might be triggered in this phase and for
230 // which being declared MP when in fact not, is a problem - then
231 // the bootstrap routine for the stub generator needs to check
232 // the processor count directly and leave the bootstrap routine
233 // in place until called after initialization has ocurred.
234 return (_processor_count != 1) || AssumeMP;
235 }
236 static julong available_memory();
237 static julong physical_memory();
238 static bool has_allocatable_memory_limit(julong* limit);
239 static bool is_server_class_machine();
240
241 // number of CPUs
242 static int processor_count() {
243 return _processor_count;
244 }
245 static void set_processor_count(int count) { _processor_count = count; }
246
247 // Returns the number of CPUs this process is currently allowed to run on.
248 // Note that on some OSes this can change dynamically.
249 static int active_processor_count();
250
251 // At startup the number of active CPUs this process is allowed to run on.
252 // This value does not change dynamically. May be different from active_processor_count().
253 static int initial_active_processor_count() {
254 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
255 return _initial_active_processor_count;
256 }
257
258 // Bind processes to processors.
259 // This is a two step procedure:
260 // first you generate a distribution of processes to processors,
261 // then you bind processes according to that distribution.
262 // Compute a distribution for number of processes to processors.
263 // Stores the processor id's into the distribution array argument.
264 // Returns true if it worked, false if it didn't.
265 static bool distribute_processes(uint length, uint* distribution);
266 // Binds the current process to a processor.
267 // Returns true if it worked, false if it didn't.
268 static bool bind_to_processor(uint processor_id);
269
270 // Give a name to the current thread.
271 static void set_native_thread_name(const char *name);
272
273 // Interface for stack banging (predetect possible stack overflow for
274 // exception processing) There are guard pages, and above that shadow
275 // pages for stack overflow checking.
276 static bool uses_stack_guard_pages();
277 static bool allocate_stack_guard_pages();
278 static void bang_stack_shadow_pages();
279 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
280
281 // OS interface to Virtual Memory
282
283 // Return the default page size.
284 static int vm_page_size();
285
286 // Returns the page size to use for a region of memory.
287 // region_size / min_pages will always be greater than or equal to the
288 // returned value. The returned value will divide region_size.
289 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
290
291 // Returns the page size to use for a region of memory.
292 // region_size / min_pages will always be greater than or equal to the
293 // returned value. The returned value might not divide region_size.
294 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
295
296 // Return the largest page size that can be used
297 static size_t max_page_size() {
298 // The _page_sizes array is sorted in descending order.
299 return _page_sizes[0];
300 }
301
302 // Methods for tracing page sizes returned by the above method; enabled by
303 // TracePageSizes. The region_{min,max}_size parameters should be the values
304 // passed to page_size_for_region() and page_size should be the result of that
305 // call. The (optional) base and size parameters should come from the
306 // ReservedSpace base() and size() methods.
307 static void trace_page_sizes(const char* str, const size_t* page_sizes,
308 int count) PRODUCT_RETURN;
309 static void trace_page_sizes(const char* str, const size_t region_min_size,
310 const size_t region_max_size,
311 const size_t page_size,
312 const char* base = NULL,
313 const size_t size = 0) PRODUCT_RETURN;
314
315 static int vm_allocation_granularity();
316 static char* reserve_memory(size_t bytes, char* addr = 0,
317 size_t alignment_hint = 0);
318 static char* reserve_memory(size_t bytes, char* addr,
319 size_t alignment_hint, MEMFLAGS flags);
320 static char* reserve_memory_aligned(size_t size, size_t alignment);
321 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
322 static void split_reserved_memory(char *base, size_t size,
323 size_t split, bool realloc);
324 static bool commit_memory(char* addr, size_t bytes, bool executable);
325 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
326 bool executable);
327 // Same as commit_memory() that either succeeds or calls
328 // vm_exit_out_of_memory() with the specified mesg.
329 static void commit_memory_or_exit(char* addr, size_t bytes,
330 bool executable, const char* mesg);
331 static void commit_memory_or_exit(char* addr, size_t size,
332 size_t alignment_hint,
333 bool executable, const char* mesg);
334 static bool uncommit_memory(char* addr, size_t bytes);
335 static bool release_memory(char* addr, size_t bytes);
336
337 // Touch memory pages that cover the memory range from start to end (exclusive)
338 // to make the OS back the memory range with actual memory.
339 // Current implementation may not touch the last page if unaligned addresses
340 // are passed.
341 static void pretouch_memory(char* start, char* end);
342
343 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
344 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
345 bool is_committed = true);
346
347 static bool guard_memory(char* addr, size_t bytes);
348 static bool unguard_memory(char* addr, size_t bytes);
349 static bool create_stack_guard_pages(char* addr, size_t bytes);
350 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
351 static bool remove_stack_guard_pages(char* addr, size_t bytes);
352
353 static char* map_memory(int fd, const char* file_name, size_t file_offset,
354 char *addr, size_t bytes, bool read_only = false,
355 bool allow_exec = false);
356 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
357 char *addr, size_t bytes, bool read_only,
358 bool allow_exec);
359 static bool unmap_memory(char *addr, size_t bytes);
360 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
361 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
362
363 // NUMA-specific interface
364 static bool numa_has_static_binding();
365 static bool numa_has_group_homing();
366 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
367 static void numa_make_global(char *addr, size_t bytes);
368 static size_t numa_get_groups_num();
369 static size_t numa_get_leaf_groups(int *ids, size_t size);
370 static bool numa_topology_changed();
371 static int numa_get_group_id();
372
373 // Page manipulation
374 struct page_info {
375 size_t size;
376 int lgrp_id;
377 };
378 static bool get_page_info(char *start, page_info* info);
379 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
380
381 static char* non_memory_address_word();
382 // reserve, commit and pin the entire memory region
383 static char* reserve_memory_special(size_t size, size_t alignment,
384 char* addr, bool executable);
385 static bool release_memory_special(char* addr, size_t bytes);
386 static void large_page_init();
387 static size_t large_page_size();
388 static bool can_commit_large_page_memory();
389 static bool can_execute_large_page_memory();
390
391 // OS interface to polling page
392 static address get_polling_page() { return _polling_page; }
393 static void set_polling_page(address page) { _polling_page = page; }
394 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
395 static void make_polling_page_unreadable();
396 static void make_polling_page_readable();
397
398 // Routines used to serialize the thread state without using membars
399 static void serialize_thread_states();
400
401 // Since we write to the serialize page from every thread, we
402 // want stores to be on unique cache lines whenever possible
403 // in order to minimize CPU cross talk. We pre-compute the
404 // amount to shift the thread* to make this offset unique to
405 // each thread.
406 static int get_serialize_page_shift_count() {
407 return SerializePageShiftCount;
408 }
409
410 static void set_serialize_page_mask(uintptr_t mask) {
411 _serialize_page_mask = mask;
412 }
413
414 static unsigned int get_serialize_page_mask() {
415 return _serialize_page_mask;
416 }
417
418 static void set_memory_serialize_page(address page);
419
420 static address get_memory_serialize_page() {
421 return (address)_mem_serialize_page;
422 }
423
424 static inline void write_memory_serialize_page(JavaThread *thread) {
425 uintptr_t page_offset = ((uintptr_t)thread >>
426 get_serialize_page_shift_count()) &
427 get_serialize_page_mask();
428 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
429 }
430
431 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
432 if (UseMembar) return false;
433 // Previously this function calculated the exact address of this
434 // thread's serialize page, and checked if the faulting address
435 // was equal. However, some platforms mask off faulting addresses
436 // to the page size, so now we just check that the address is
437 // within the page. This makes the thread argument unnecessary,
438 // but we retain the NULL check to preserve existing behaviour.
439 if (thread == NULL) return false;
440 address page = (address) _mem_serialize_page;
441 return addr >= page && addr < (page + os::vm_page_size());
442 }
443
444 static void block_on_serialize_page_trap();
445
446 // threads
447
448 enum ThreadType {
449 vm_thread,
450 cgc_thread, // Concurrent GC thread
451 pgc_thread, // Parallel GC thread
452 java_thread,
453 compiler_thread,
454 watcher_thread,
455 os_thread
456 };
457
458 static bool create_thread(Thread* thread,
459 ThreadType thr_type,
460 size_t stack_size = 0);
461
462 // The "main thread", also known as "starting thread", is the thread
463 // that loads/creates the JVM via JNI_CreateJavaVM.
464 static bool create_main_thread(JavaThread* thread);
465
466 // The primordial thread is the initial process thread. The java
467 // launcher never uses the primordial thread as the main thread, but
468 // applications that host the JVM directly may do so. Some platforms
469 // need special-case handling of the primordial thread if it attaches
470 // to the VM.
471 static bool is_primordial_thread(void)
472 #if defined(_WINDOWS) || defined(BSD)
473 // No way to identify the primordial thread.
474 { return false; }
475 #else
476 ;
477 #endif
478
479 static bool create_attached_thread(JavaThread* thread);
480 static void pd_start_thread(Thread* thread);
481 static void start_thread(Thread* thread);
482
483 static void initialize_thread(Thread* thr);
484 static void free_thread(OSThread* osthread);
485
486 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
487 static intx current_thread_id();
488 static int current_process_id();
489 static int sleep(Thread* thread, jlong ms, bool interruptable);
490 // Short standalone OS sleep suitable for slow path spin loop.
491 // Ignores Thread.interrupt() (so keep it short).
492 // ms = 0, will sleep for the least amount of time allowed by the OS.
493 static void naked_short_sleep(jlong ms);
494 static void infinite_sleep(); // never returns, use with CAUTION
495 static void yield(); // Yields to all threads with same priority
496 enum YieldResult {
497 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
498 YIELD_NONEREADY = 0, // No other runnable/ready threads.
499 // platform-specific yield return immediately
500 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
501 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
502 // yield that can be used in lieu of blocking.
503 } ;
504 static YieldResult NakedYield () ;
505 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
506 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
507 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
508 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
509
510 static void interrupt(Thread* thread);
511 static bool is_interrupted(Thread* thread, bool clear_interrupted);
512
513 static int pd_self_suspend_thread(Thread* thread);
514
515 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
516 static frame fetch_frame_from_context(void* ucVoid);
517
518 static ExtendedPC get_thread_pc(Thread *thread);
519 static void breakpoint();
520
521 static address current_stack_pointer();
522 static address current_stack_base();
523 static size_t current_stack_size();
524
525 static void verify_stack_alignment() PRODUCT_RETURN;
526
527 static int message_box(const char* title, const char* message);
528 static char* do_you_want_to_debug(const char* message);
529
530 // run cmd in a separate process and return its exit code; or -1 on failures
531 static int fork_and_exec(char *cmd, bool use_vfork_if_available = false);
532
533 // os::exit() is merged with vm_exit()
534 // static void exit(int num);
535
536 // Terminate the VM, but don't exit the process
537 static void shutdown();
538
539 // Terminate with an error. Default is to generate a core file on platforms
540 // that support such things. This calls shutdown() and then aborts.
541 static void abort(bool dump_core = true);
542
543 // Die immediately, no exit hook, no abort hook, no cleanup.
544 static void die();
545
546 // File i/o operations
547 static const int default_file_open_flags();
548 static int open(const char *path, int oflag, int mode);
549 static FILE* open(int fd, const char* mode);
550 static int close(int fd);
551 static jlong lseek(int fd, jlong offset, int whence);
552 static char* native_path(char *path);
553 static int ftruncate(int fd, jlong length);
554 static int fsync(int fd);
555 static int available(int fd, jlong *bytes);
556
557 //File i/o operations
558
559 static size_t read(int fd, void *buf, unsigned int nBytes);
560 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
561 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
562 static size_t write(int fd, const void *buf, unsigned int nBytes);
563
564 // Reading directories.
565 static DIR* opendir(const char* dirname);
566 static struct dirent* readdir(DIR* dirp);
567 static int closedir(DIR* dirp);
568
569 // Dynamic library extension
570 static const char* dll_file_extension();
571
572 static const char* get_temp_directory();
573 static const char* get_current_directory(char *buf, size_t buflen);
574
575 // Builds a platform-specific full library path given a ld path and lib name
576 // Returns true if buffer contains full path to existing file, false otherwise
577 static bool dll_build_name(char* buffer, size_t size,
578 const char* pathname, const char* fname);
579
580 // Symbol lookup, find nearest function name; basically it implements
581 // dladdr() for all platforms. Name of the nearest function is copied
582 // to buf. Distance from its base address is optionally returned as offset.
583 // If function name is not found, buf[0] is set to '\0' and offset is
584 // set to -1 (if offset is non-NULL).
585 static bool dll_address_to_function_name(address addr, char* buf,
586 int buflen, int* offset);
587
588 // Locate DLL/DSO. On success, full path of the library is copied to
589 // buf, and offset is optionally set to be the distance between addr
590 // and the library's base address. On failure, buf[0] is set to '\0'
591 // and offset is set to -1 (if offset is non-NULL).
592 static bool dll_address_to_library_name(address addr, char* buf,
593 int buflen, int* offset);
594
595 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
596 static bool address_is_in_vm(address addr);
597
598 // Loads .dll/.so and
599 // in case of error it checks if .dll/.so was built for the
600 // same architecture as Hotspot is running on
601 static void* dll_load(const char *name, char *ebuf, int ebuflen);
602
603 // lookup symbol in a shared library
604 static void* dll_lookup(void* handle, const char* name);
605
606 // Unload library
607 static void dll_unload(void *lib);
608
609 // Callback for loaded module information
610 // Input parameters:
611 // char* module_file_name,
612 // address module_base_addr,
613 // address module_top_addr,
614 // void* param
615 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
616
617 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
618
619 // Return the handle of this process
620 static void* get_default_process_handle();
621
622 // Check for static linked agent library
623 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
624 size_t syms_len);
625
626 // Find agent entry point
627 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
628 const char *syms[], size_t syms_len);
629
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 // Print out system information; they are called by fatal error handler.
634 // Output format may be different on different platforms.
635 static void print_os_info(outputStream* st);
636 static void print_os_info_brief(outputStream* st);
637 static void print_cpu_info(outputStream* st);
638 static void pd_print_cpu_info(outputStream* st);
639 static void print_memory_info(outputStream* st);
640 static void print_dll_info(outputStream* st);
641 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
642 static void print_context(outputStream* st, void* context);
643 static void print_register_info(outputStream* st, void* context);
644 static void print_siginfo(outputStream* st, void* siginfo);
645 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
646 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
647
648 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
649 static size_t lasterror(char *buf, size_t len);
650 static int get_last_error();
651
652 // Determines whether the calling process is being debugged by a user-mode debugger.
653 static bool is_debugger_attached();
654
655 // wait for a key press if PauseAtExit is set
656 static void wait_for_keypress_at_exit(void);
657
658 // The following two functions are used by fatal error handler to trace
659 // native (C) frames. They are not part of frame.hpp/frame.cpp because
660 // frame.hpp/cpp assume thread is JavaThread, and also because different
661 // OS/compiler may have different convention or provide different API to
662 // walk C frames.
663 //
664 // We don't attempt to become a debugger, so we only follow frames if that
665 // does not require a lookup in the unwind table, which is part of the binary
666 // file but may be unsafe to read after a fatal error. So on x86, we can
667 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
668 // possible to walk C stack without having the unwind table.
669 static bool is_first_C_frame(frame *fr);
670 static frame get_sender_for_C_frame(frame *fr);
671
672 // return current frame. pc() and sp() are set to NULL on failure.
673 static frame current_frame();
674
675 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
676
677 // returns a string to describe the exception/signal;
678 // returns NULL if exception_code is not an OS exception/signal.
679 static const char* exception_name(int exception_code, char* buf, size_t buflen);
680
681 // Returns native Java library, loads if necessary
682 static void* native_java_library();
683
684 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
685 static void jvm_path(char *buf, jint buflen);
686
687 // Returns true if we are running in a headless jre.
688 static bool is_headless_jre();
689
690 // JNI names
691 static void print_jni_name_prefix_on(outputStream* st, int args_size);
692 static void print_jni_name_suffix_on(outputStream* st, int args_size);
693
694 // File conventions
695 static const char* file_separator();
696 static const char* line_separator();
697 static const char* path_separator();
698
699 // Init os specific system properties values
700 static void init_system_properties_values();
701
702 // IO operations, non-JVM_ version.
703 static int stat(const char* path, struct stat* sbuf);
704 static bool dir_is_empty(const char* path);
705
706 // IO operations on binary files
707 static int create_binary_file(const char* path, bool rewrite_existing);
708 static jlong current_file_offset(int fd);
709 static jlong seek_to_file_offset(int fd, jlong offset);
710
711 // Thread Local Storage
712 static int allocate_thread_local_storage();
713 static void thread_local_storage_at_put(int index, void* value);
714 static void* thread_local_storage_at(int index);
715 static void free_thread_local_storage(int index);
716
717 // Retrieve native stack frames.
718 // Parameter:
719 // stack: an array to storage stack pointers.
720 // frames: size of above array.
721 // toSkip: number of stack frames to skip at the beginning.
722 // Return: number of stack frames captured.
723 static int get_native_stack(address* stack, int size, int toSkip = 0);
724
725 // General allocation (must be MT-safe)
726 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
727 static void* malloc (size_t size, MEMFLAGS flags);
728 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
729 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
730
731 static void free (void *memblock, MEMFLAGS flags = mtNone);
732 static bool check_heap(bool force = false); // verify C heap integrity
733 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
734
735 #ifndef PRODUCT
736 static julong num_mallocs; // # of calls to malloc/realloc
737 static julong alloc_bytes; // # of bytes allocated
738 static julong num_frees; // # of calls to free
739 static julong free_bytes; // # of bytes freed
740 #endif
741
742 // SocketInterface (ex HPI SocketInterface )
743 static int socket(int domain, int type, int protocol);
744 static int socket_close(int fd);
745 static int socket_shutdown(int fd, int howto);
746 static int recv(int fd, char* buf, size_t nBytes, uint flags);
747 static int send(int fd, char* buf, size_t nBytes, uint flags);
748 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
749 static int timeout(int fd, long timeout);
750 static int listen(int fd, int count);
751 static int connect(int fd, struct sockaddr* him, socklen_t len);
752 static int bind(int fd, struct sockaddr* him, socklen_t len);
753 static int accept(int fd, struct sockaddr* him, socklen_t* len);
754 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
755 struct sockaddr* from, socklen_t* fromlen);
756 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
757 static int sendto(int fd, char* buf, size_t len, uint flags,
758 struct sockaddr* to, socklen_t tolen);
759 static int socket_available(int fd, jint* pbytes);
760
761 static int get_sock_opt(int fd, int level, int optname,
762 char* optval, socklen_t* optlen);
763 static int set_sock_opt(int fd, int level, int optname,
764 const char* optval, socklen_t optlen);
765 static int get_host_name(char* name, int namelen);
766
767 static struct hostent* get_host_by_name(char* name);
768
769 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
770 static void signal_init();
771 static void signal_init_pd();
772 static void signal_notify(int signal_number);
773 static void* signal(int signal_number, void* handler);
774 static void signal_raise(int signal_number);
775 static int signal_wait();
776 static int signal_lookup();
777 static void* user_handler();
778 static void terminate_signal_thread();
779 static int sigexitnum_pd();
780
781 // random number generation
782 static long random(); // return 32bit pseudorandom number
783 static void init_random(long initval); // initialize random sequence
784
785 // Structured OS Exception support
786 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
787
788 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
789 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
790
791 // Get the default path to the core file
792 // Returns the length of the string
793 static int get_core_path(char* buffer, size_t bufferSize);
794
795 // JVMTI & JVM monitoring and management support
796 // The thread_cpu_time() and current_thread_cpu_time() are only
797 // supported if is_thread_cpu_time_supported() returns true.
798 // They are not supported on Solaris T1.
799
800 // Thread CPU Time - return the fast estimate on a platform
801 // On Solaris - call gethrvtime (fast) - user time only
802 // On Linux - fast clock_gettime where available - user+sys
803 // - otherwise: very slow /proc fs - user+sys
804 // On Windows - GetThreadTimes - user+sys
805 static jlong current_thread_cpu_time();
806 static jlong thread_cpu_time(Thread* t);
807
808 // Thread CPU Time with user_sys_cpu_time parameter.
809 //
810 // If user_sys_cpu_time is true, user+sys time is returned.
811 // Otherwise, only user time is returned
812 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
813 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
814
815 // Return a bunch of info about the timers.
816 // Note that the returned info for these two functions may be different
817 // on some platforms
818 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
819 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
820
821 static bool is_thread_cpu_time_supported();
822
823 // System loadavg support. Returns -1 if load average cannot be obtained.
824 static int loadavg(double loadavg[], int nelem);
825
826 // Hook for os specific jvm options that we don't want to abort on seeing
827 static bool obsolete_option(const JavaVMOption *option);
828
829 // Extensions
830 #include "runtime/os_ext.hpp"
831
832 public:
833 class CrashProtectionCallback : public StackObj {
834 public:
835 virtual void call() = 0;
836 };
837
838 // Platform dependent stuff
839 #ifdef TARGET_OS_FAMILY_linux
840 # include "os_linux.hpp"
841 # include "os_posix.hpp"
842 #endif
843 #ifdef TARGET_OS_FAMILY_solaris
844 # include "os_solaris.hpp"
845 # include "os_posix.hpp"
846 #endif
847 #ifdef TARGET_OS_FAMILY_windows
848 # include "os_windows.hpp"
849 #endif
850 #ifdef TARGET_OS_FAMILY_aix
851 # include "os_aix.hpp"
852 # include "os_posix.hpp"
853 #endif
854 #ifdef TARGET_OS_FAMILY_bsd
855 # include "os_posix.hpp"
856 # include "os_bsd.hpp"
857 #endif
858 #ifdef TARGET_OS_ARCH_linux_x86
859 # include "os_linux_x86.hpp"
860 #endif
861 #ifdef TARGET_OS_ARCH_linux_aarch64
862 # include "os_linux_aarch64.hpp"
863 #endif
864 #ifdef TARGET_OS_ARCH_linux_sparc
865 # include "os_linux_sparc.hpp"
866 #endif
867 #ifdef TARGET_OS_ARCH_linux_zero
868 # include "os_linux_zero.hpp"
869 #endif
870 #ifdef TARGET_OS_ARCH_solaris_x86
871 # include "os_solaris_x86.hpp"
872 #endif
873 #ifdef TARGET_OS_ARCH_solaris_sparc
874 # include "os_solaris_sparc.hpp"
875 #endif
876 #ifdef TARGET_OS_ARCH_windows_x86
877 # include "os_windows_x86.hpp"
878 #endif
879 #ifdef TARGET_OS_ARCH_linux_arm
880 # include "os_linux_arm.hpp"
881 #endif
882 #ifdef TARGET_OS_ARCH_linux_ppc
883 # include "os_linux_ppc.hpp"
884 #endif
885 #ifdef TARGET_OS_ARCH_aix_ppc
886 # include "os_aix_ppc.hpp"
887 #endif
888 #ifdef TARGET_OS_ARCH_bsd_x86
889 # include "os_bsd_x86.hpp"
890 #endif
891 #ifdef TARGET_OS_ARCH_bsd_zero
892 # include "os_bsd_zero.hpp"
893 #endif
894
895 public:
896 #ifndef PLATFORM_PRINT_NATIVE_STACK
897 // No platform-specific code for printing the native stack.
898 static bool platform_print_native_stack(outputStream* st, void* context,
899 char *buf, int buf_size) {
900 return false;
901 }
902 #endif
903
904 // debugging support (mostly used by debug.cpp but also fatal error handler)
905 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
906
907 static bool dont_yield(); // when true, JVM_Yield() is nop
908 static void print_statistics();
909
910 // Thread priority helpers (implemented in OS-specific part)
911 static OSReturn set_native_priority(Thread* thread, int native_prio);
912 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
913 static int java_to_os_priority[CriticalPriority + 1];
914 // Hint to the underlying OS that a task switch would not be good.
915 // Void return because it's a hint and can fail.
916 static void hint_no_preempt();
917
918 // Used at creation if requested by the diagnostic flag PauseAtStartup.
919 // Causes the VM to wait until an external stimulus has been applied
920 // (for Unix, that stimulus is a signal, for Windows, an external
921 // ResumeThread call)
922 static void pause();
923
924 // Builds a platform dependent Agent_OnLoad_<libname> function name
925 // which is used to find statically linked in agents.
926 static char* build_agent_function_name(const char *sym, const char *cname,
927 bool is_absolute_path);
928
929 class SuspendedThreadTaskContext {
930 public:
931 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
932 Thread* thread() const { return _thread; }
933 void* ucontext() const { return _ucontext; }
934 private:
935 Thread* _thread;
936 void* _ucontext;
937 };
938
939 class SuspendedThreadTask {
940 public:
941 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
942 virtual ~SuspendedThreadTask() {}
943 void run();
944 bool is_done() { return _done; }
945 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
946 protected:
947 private:
948 void internal_do_task();
949 Thread* _thread;
950 bool _done;
951 };
952
953 #ifndef TARGET_OS_FAMILY_windows
954 // Suspend/resume support
955 // Protocol:
956 //
957 // a thread starts in SR_RUNNING
958 //
959 // SR_RUNNING can go to
960 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
961 // SR_SUSPEND_REQUEST can go to
962 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
963 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
964 // SR_SUSPENDED can go to
965 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
966 // SR_WAKEUP_REQUEST can go to
967 // * SR_RUNNING when the stopped thread receives the signal
968 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
969 class SuspendResume {
970 public:
971 enum State {
972 SR_RUNNING,
973 SR_SUSPEND_REQUEST,
974 SR_SUSPENDED,
975 SR_WAKEUP_REQUEST
976 };
977
978 private:
979 volatile State _state;
980
981 private:
982 /* try to switch state from state "from" to state "to"
983 * returns the state set after the method is complete
984 */
985 State switch_state(State from, State to);
986
987 public:
988 SuspendResume() : _state(SR_RUNNING) { }
989
990 State state() const { return _state; }
991
992 State request_suspend() {
993 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
994 }
995
996 State cancel_suspend() {
997 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
998 }
999
1000 State suspended() {
1001 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
1002 }
1003
1004 State request_wakeup() {
1005 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
1006 }
1007
1008 State running() {
1009 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
1010 }
1011
1012 bool is_running() const {
1013 return _state == SR_RUNNING;
1014 }
1015
1016 bool is_suspend_request() const {
1017 return _state == SR_SUSPEND_REQUEST;
1018 }
1019
1020 bool is_suspended() const {
1021 return _state == SR_SUSPENDED;
1022 }
1023 };
1024 #endif
1025
1026
1027 protected:
1028 static long _rand_seed; // seed for random number generator
1029 static int _processor_count; // number of processors
1030 static int _initial_active_processor_count; // number of active processors during initialization.
1031
1032 static char* format_boot_path(const char* format_string,
1033 const char* home,
1034 int home_len,
1035 char fileSep,
1036 char pathSep);
1037 static bool set_boot_path(char fileSep, char pathSep);
1038 static char** split_path(const char* path, int* n);
1039
1040 };
1041
1042 // Note that "PAUSE" is almost always used with synchronization
1043 // so arguably we should provide Atomic::SpinPause() instead
1044 // of the global SpinPause() with C linkage.
1045 // It'd also be eligible for inlining on many platforms.
1046
1047 extern "C" int SpinPause();
1048
1049 #endif // SHARE_VM_RUNTIME_OS_HPP