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 "runtime/handles.hpp"
32 #include "utilities/top.hpp"
33 #ifdef TARGET_OS_FAMILY_linux
34 # include "jvm_linux.h"
35 # include <setjmp.h>
36 #endif
37 #ifdef TARGET_OS_FAMILY_solaris
38 # include "jvm_solaris.h"
39 # include <setjmp.h>
40 #endif
41 #ifdef TARGET_OS_FAMILY_windows
42 # include "jvm_windows.h"
43 #endif
44 #ifdef TARGET_OS_FAMILY_aix
45 # include "jvm_aix.h"
46 # include <setjmp.h>
47 #endif
48 #ifdef TARGET_OS_FAMILY_bsd
49 # include "jvm_bsd.h"
50 # include <setjmp.h>
51 # ifdef __APPLE__
52 # include <mach/mach_time.h>
53 # endif
54 #endif
55
56 class AgentLibrary;
57
58 // os defines the interface to operating system; this includes traditional
59 // OS services (time, I/O) as well as other functionality with system-
60 // dependent code.
61
62 typedef void (*dll_func)(...);
63
64 class Thread;
65 class JavaThread;
66 class Event;
67 class DLL;
68 class FileHandle;
69 class NativeCallStack;
70
71 template<class E> class GrowableArray;
72
73 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
74
75 // Platform-independent error return values from OS functions
76 enum OSReturn {
77 OS_OK = 0, // Operation was successful
78 OS_ERR = -1, // Operation failed
79 OS_INTRPT = -2, // Operation was interrupted
80 OS_TIMEOUT = -3, // Operation timed out
81 OS_NOMEM = -5, // Operation failed for lack of memory
82 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
83 };
84
85 enum ThreadPriority { // JLS 20.20.1-3
86 NoPriority = -1, // Initial non-priority value
87 MinPriority = 1, // Minimum priority
88 NormPriority = 5, // Normal (non-daemon) priority
89 NearMaxPriority = 9, // High priority, used for VMThread
90 MaxPriority = 10, // Highest priority, used for WatcherThread
91 // ensures that VMThread doesn't starve profiler
92 CriticalPriority = 11 // Critical thread priority
93 };
94
95 // Executable parameter flag for os::commit_memory() and
96 // os::commit_memory_or_exit().
97 const bool ExecMem = true;
98
99 // Typedef for structured exception handling support
100 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
101
102 class MallocTracker;
103
104 class os: AllStatic {
105 friend class VMStructs;
106 friend class MallocTracker;
107 public:
108 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
109
110 private:
111 static OSThread* _starting_thread;
112 static address _polling_page;
113 static volatile int32_t * _mem_serialize_page;
114 static uintptr_t _serialize_page_mask;
115 public:
116 static size_t _page_sizes[page_sizes_max];
117
118 private:
119 static void init_page_sizes(size_t default_page_size) {
120 _page_sizes[0] = default_page_size;
121 _page_sizes[1] = 0; // sentinel
122 }
123
124 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
125 size_t alignment_hint = 0);
126 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
127 static void pd_split_reserved_memory(char *base, size_t size,
128 size_t split, bool realloc);
129 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
130 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
131 bool executable);
132 // Same as pd_commit_memory() that either succeeds or calls
133 // vm_exit_out_of_memory() with the specified mesg.
134 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
135 bool executable, const char* mesg);
136 static void pd_commit_memory_or_exit(char* addr, size_t size,
137 size_t alignment_hint,
138 bool executable, const char* mesg);
139 static bool pd_uncommit_memory(char* addr, size_t bytes);
140 static bool pd_release_memory(char* addr, size_t bytes);
141
142 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
143 char *addr, size_t bytes, bool read_only = false,
144 bool allow_exec = false);
145 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
146 char *addr, size_t bytes, bool read_only,
147 bool allow_exec);
148 static bool pd_unmap_memory(char *addr, size_t bytes);
149 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
150 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
151
152 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
153
154 static void initialize_initial_active_processor_count();
155
156 LINUX_ONLY(static void pd_init_container_support();)
157
158 public:
159 static void init(void); // Called before command line parsing
160
161 static void init_container_support() { // Called during command line parsing.
162 LINUX_ONLY(pd_init_container_support();)
163 }
164
165 static void init_before_ergo(void); // Called after command line parsing
166 // before VM ergonomics processing.
167 static jint init_2(void); // Called after command line parsing
168 // and VM ergonomics processing
169 static void init_globals(void) { // Called from init_globals() in init.cpp
170 init_globals_ext();
171 }
172
173 // File names are case-insensitive on windows only
174 // Override me as needed
175 static int file_name_strcmp(const char* s1, const char* s2);
176
177 // get/unset environment variable
178 static bool getenv(const char* name, char* buffer, int len);
179 static bool unsetenv(const char* name);
180
181 static bool have_special_privileges();
182
183 static jlong javaTimeMillis();
184 static jlong javaTimeNanos();
185 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
186 static void run_periodic_checks();
187
188
189 // Returns the elapsed time in seconds since the vm started.
190 static double elapsedTime();
191
192 // Returns real time in seconds since an arbitrary point
193 // in the past.
194 static bool getTimesSecs(double* process_real_time,
195 double* process_user_time,
196 double* process_system_time);
197
198 // Interface to the performance counter
199 static jlong elapsed_counter();
200 static jlong elapsed_frequency();
201
202 // The "virtual time" of a thread is the amount of time a thread has
203 // actually run. The first function indicates whether the OS supports
204 // this functionality for the current thread, and if so:
205 // * the second enables vtime tracking (if that is required).
206 // * the third tells whether vtime is enabled.
207 // * the fourth returns the elapsed virtual time for the current
208 // thread.
209 static bool supports_vtime();
210 static bool enable_vtime();
211 static bool vtime_enabled();
212 static double elapsedVTime();
213
214 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
215 // It is MT safe, but not async-safe, as reading time zone
216 // information may require a lock on some platforms.
217 static char* local_time_string(char *buf, size_t buflen);
218 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
219 // Fill in buffer with current local time as an ISO-8601 string.
220 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
221 // Returns buffer, or NULL if it failed.
222 static char* iso8601_time(char* buffer, size_t buffer_length);
223
224 // Interface for detecting multiprocessor system
225 static inline bool is_MP() {
226 // During bootstrap if _processor_count is not yet initialized
227 // we claim to be MP as that is safest. If any platform has a
228 // stub generator that might be triggered in this phase and for
229 // which being declared MP when in fact not, is a problem - then
230 // the bootstrap routine for the stub generator needs to check
231 // the processor count directly and leave the bootstrap routine
232 // in place until called after initialization has ocurred.
233 return (_processor_count != 1) || AssumeMP;
234 }
235 static julong available_memory();
236 static julong physical_memory();
237 static bool has_allocatable_memory_limit(julong* limit);
238 static bool is_server_class_machine();
239
240 // number of CPUs
241 static int processor_count() {
242 return _processor_count;
243 }
244 static void set_processor_count(int count) { _processor_count = count; }
245
246 // Returns the number of CPUs this process is currently allowed to run on.
247 // Note that on some OSes this can change dynamically.
248 static int active_processor_count();
249
250 // At startup the number of active CPUs this process is allowed to run on.
251 // This value does not change dynamically. May be different from active_processor_count().
252 static int initial_active_processor_count() {
253 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
254 return _initial_active_processor_count;
255 }
256
257 // Bind processes to processors.
258 // This is a two step procedure:
259 // first you generate a distribution of processes to processors,
260 // then you bind processes according to that distribution.
261 // Compute a distribution for number of processes to processors.
262 // Stores the processor id's into the distribution array argument.
263 // Returns true if it worked, false if it didn't.
264 static bool distribute_processes(uint length, uint* distribution);
265 // Binds the current process to a processor.
266 // Returns true if it worked, false if it didn't.
267 static bool bind_to_processor(uint processor_id);
268
269 // Give a name to the current thread.
270 static void set_native_thread_name(const char *name);
271
272 // Interface for stack banging (predetect possible stack overflow for
273 // exception processing) There are guard pages, and above that shadow
274 // pages for stack overflow checking.
275 static bool uses_stack_guard_pages();
276 static bool allocate_stack_guard_pages();
277 static void bang_stack_shadow_pages();
278 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
279
280 // OS interface to Virtual Memory
281
282 // Return the default page size.
283 static int vm_page_size();
284
285 // Returns the page size to use for a region of memory.
286 // region_size / min_pages will always be greater than or equal to the
287 // returned value. The returned value will divide region_size.
288 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
289
290 // Returns the page size to use for a region of memory.
291 // region_size / min_pages will always be greater than or equal to the
292 // returned value. The returned value might not divide region_size.
293 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
294
295 // Return the largest page size that can be used
296 static size_t max_page_size() {
297 // The _page_sizes array is sorted in descending order.
298 return _page_sizes[0];
299 }
300
301 // Methods for tracing page sizes returned by the above method; enabled by
302 // TracePageSizes. The region_{min,max}_size parameters should be the values
303 // passed to page_size_for_region() and page_size should be the result of that
304 // call. The (optional) base and size parameters should come from the
305 // ReservedSpace base() and size() methods.
306 static void trace_page_sizes(const char* str, const size_t* page_sizes,
307 int count) PRODUCT_RETURN;
308 static void trace_page_sizes(const char* str, const size_t region_min_size,
309 const size_t region_max_size,
310 const size_t page_size,
311 const char* base = NULL,
312 const size_t size = 0) PRODUCT_RETURN;
313
314 static int vm_allocation_granularity();
315 static char* reserve_memory(size_t bytes, char* addr = 0,
316 size_t alignment_hint = 0);
317 static char* reserve_memory(size_t bytes, char* addr,
318 size_t alignment_hint, MEMFLAGS flags);
319 static char* reserve_memory_aligned(size_t size, size_t alignment);
320 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
321 static void split_reserved_memory(char *base, size_t size,
322 size_t split, bool realloc);
323 static bool commit_memory(char* addr, size_t bytes, bool executable);
324 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
325 bool executable);
326 // Same as commit_memory() that either succeeds or calls
327 // vm_exit_out_of_memory() with the specified mesg.
328 static void commit_memory_or_exit(char* addr, size_t bytes,
329 bool executable, const char* mesg);
330 static void commit_memory_or_exit(char* addr, size_t size,
331 size_t alignment_hint,
332 bool executable, const char* mesg);
333 static bool uncommit_memory(char* addr, size_t bytes);
334 static bool release_memory(char* addr, size_t bytes);
335
336 // Touch memory pages that cover the memory range from start to end (exclusive)
337 // to make the OS back the memory range with actual memory.
338 // Current implementation may not touch the last page if unaligned addresses
339 // are passed.
340 static void pretouch_memory(char* start, char* end);
341
342 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
343 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
344 bool is_committed = true);
345
346 static bool guard_memory(char* addr, size_t bytes);
347 static bool unguard_memory(char* addr, size_t bytes);
348 static bool create_stack_guard_pages(char* addr, size_t bytes);
349 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
350 static bool remove_stack_guard_pages(char* addr, size_t bytes);
351
352 static char* map_memory(int fd, const char* file_name, size_t file_offset,
353 char *addr, size_t bytes, bool read_only = false,
354 bool allow_exec = false);
355 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
356 char *addr, size_t bytes, bool read_only,
357 bool allow_exec);
358 static bool unmap_memory(char *addr, size_t bytes);
359 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
360 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
361
362 // NUMA-specific interface
363 static bool numa_has_static_binding();
364 static bool numa_has_group_homing();
365 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
366 static void numa_make_global(char *addr, size_t bytes);
367 static size_t numa_get_groups_num();
368 static size_t numa_get_leaf_groups(int *ids, size_t size);
369 static bool numa_topology_changed();
370 static int numa_get_group_id();
371
372 // Page manipulation
373 struct page_info {
374 size_t size;
375 int lgrp_id;
376 };
377 static bool get_page_info(char *start, page_info* info);
378 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
379
380 static char* non_memory_address_word();
381 // reserve, commit and pin the entire memory region
382 static char* reserve_memory_special(size_t size, size_t alignment,
383 char* addr, bool executable);
384 static bool release_memory_special(char* addr, size_t bytes);
385 static void large_page_init();
386 static size_t large_page_size();
387 static bool can_commit_large_page_memory();
388 static bool can_execute_large_page_memory();
389
390 // OS interface to polling page
391 static address get_polling_page() { return _polling_page; }
392 static void set_polling_page(address page) { _polling_page = page; }
393 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
394 static void make_polling_page_unreadable();
395 static void make_polling_page_readable();
396
397 // Routines used to serialize the thread state without using membars
398 static void serialize_thread_states();
399
400 // Since we write to the serialize page from every thread, we
401 // want stores to be on unique cache lines whenever possible
402 // in order to minimize CPU cross talk. We pre-compute the
403 // amount to shift the thread* to make this offset unique to
404 // each thread.
405 static int get_serialize_page_shift_count() {
406 return SerializePageShiftCount;
407 }
408
409 static void set_serialize_page_mask(uintptr_t mask) {
410 _serialize_page_mask = mask;
411 }
412
413 static unsigned int get_serialize_page_mask() {
414 return _serialize_page_mask;
415 }
416
417 static void set_memory_serialize_page(address page);
418
419 static address get_memory_serialize_page() {
420 return (address)_mem_serialize_page;
421 }
422
423 static inline void write_memory_serialize_page(JavaThread *thread) {
424 uintptr_t page_offset = ((uintptr_t)thread >>
425 get_serialize_page_shift_count()) &
426 get_serialize_page_mask();
427 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
428 }
429
430 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
431 if (UseMembar) return false;
432 // Previously this function calculated the exact address of this
433 // thread's serialize page, and checked if the faulting address
434 // was equal. However, some platforms mask off faulting addresses
435 // to the page size, so now we just check that the address is
436 // within the page. This makes the thread argument unnecessary,
437 // but we retain the NULL check to preserve existing behaviour.
438 if (thread == NULL) return false;
439 address page = (address) _mem_serialize_page;
440 return addr >= page && addr < (page + os::vm_page_size());
441 }
442
443 static void block_on_serialize_page_trap();
444
445 // threads
446
447 enum ThreadType {
448 vm_thread,
449 cgc_thread, // Concurrent GC thread
450 pgc_thread, // Parallel GC thread
451 java_thread,
452 compiler_thread,
453 watcher_thread,
454 os_thread
455 };
456
457 static bool create_thread(Thread* thread,
458 ThreadType thr_type,
459 size_t stack_size = 0);
460
461 // The "main thread", also known as "starting thread", is the thread
462 // that loads/creates the JVM via JNI_CreateJavaVM.
463 static bool create_main_thread(JavaThread* thread);
464
465 // The primordial thread is the initial process thread. The java
466 // launcher never uses the primordial thread as the main thread, but
467 // applications that host the JVM directly may do so. Some platforms
468 // need special-case handling of the primordial thread if it attaches
469 // to the VM.
470 static bool is_primordial_thread(void)
471 #if defined(_WINDOWS) || defined(BSD)
472 // No way to identify the primordial thread.
473 { return false; }
474 #else
475 ;
476 #endif
477
478 static bool create_attached_thread(JavaThread* thread);
479 static void pd_start_thread(Thread* thread);
480 static void start_thread(Thread* thread);
481
482 static void initialize_thread(Thread* thr);
483 static void free_thread(OSThread* osthread);
484
485 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
486 static intx current_thread_id();
487 static int current_process_id();
488 static int sleep(Thread* thread, jlong ms, bool interruptable);
489 // Short standalone OS sleep suitable for slow path spin loop.
490 // Ignores Thread.interrupt() (so keep it short).
491 // ms = 0, will sleep for the least amount of time allowed by the OS.
492 static void naked_short_sleep(jlong ms);
493 static void infinite_sleep(); // never returns, use with CAUTION
494 static void yield(); // Yields to all threads with same priority
495 enum YieldResult {
496 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
497 YIELD_NONEREADY = 0, // No other runnable/ready threads.
498 // platform-specific yield return immediately
499 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
500 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
501 // yield that can be used in lieu of blocking.
502 } ;
503 static YieldResult NakedYield () ;
504 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
505 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
506 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
507 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
508
509 static void interrupt(Thread* thread);
510 static bool is_interrupted(Thread* thread, bool clear_interrupted);
511
512 static int pd_self_suspend_thread(Thread* thread);
513
514 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
515 static frame fetch_frame_from_context(void* ucVoid);
516
517 static ExtendedPC get_thread_pc(Thread *thread);
518 static void breakpoint();
519
520 static address current_stack_pointer();
521 static address current_stack_base();
522 static size_t current_stack_size();
523
524 static void verify_stack_alignment() PRODUCT_RETURN;
525
526 static int message_box(const char* title, const char* message);
527 static char* do_you_want_to_debug(const char* message);
528
529 // run cmd in a separate process and return its exit code; or -1 on failures
530 static int fork_and_exec(char *cmd, bool use_vfork_if_available = false);
531
532 // os::exit() is merged with vm_exit()
533 // static void exit(int num);
534
535 // Terminate the VM, but don't exit the process
536 static void shutdown();
537
538 // Terminate with an error. Default is to generate a core file on platforms
539 // that support such things. This calls shutdown() and then aborts.
540 static void abort(bool dump_core = true);
541
542 // Die immediately, no exit hook, no abort hook, no cleanup.
543 static void die();
544
545 // File i/o operations
546 static const int default_file_open_flags();
547 static int open(const char *path, int oflag, int mode);
548 static FILE* open(int fd, const char* mode);
549 static int close(int fd);
550 static jlong lseek(int fd, jlong offset, int whence);
551 static char* native_path(char *path);
552 static int ftruncate(int fd, jlong length);
553 static int fsync(int fd);
554 static int available(int fd, jlong *bytes);
555
556 //File i/o operations
557
558 static size_t read(int fd, void *buf, unsigned int nBytes);
559 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
560 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
561 static size_t write(int fd, const void *buf, unsigned int nBytes);
562
563 // Reading directories.
564 static DIR* opendir(const char* dirname);
565 static struct dirent* readdir(DIR* dirp);
566 static int closedir(DIR* dirp);
567
568 // Dynamic library extension
569 static const char* dll_file_extension();
570
571 static const char* get_temp_directory();
572 static const char* get_current_directory(char *buf, size_t buflen);
573
574 // Builds a platform-specific full library path given a ld path and lib name
575 // Returns true if buffer contains full path to existing file, false otherwise
576 static bool dll_build_name(char* buffer, size_t size,
577 const char* pathname, const char* fname);
578
579 // Symbol lookup, find nearest function name; basically it implements
580 // dladdr() for all platforms. Name of the nearest function is copied
581 // to buf. Distance from its base address is optionally returned as offset.
582 // If function name is not found, buf[0] is set to '\0' and offset is
583 // set to -1 (if offset is non-NULL).
584 static bool dll_address_to_function_name(address addr, char* buf,
585 int buflen, int* offset);
586
587 // Locate DLL/DSO. On success, full path of the library is copied to
588 // buf, and offset is optionally set to be the distance between addr
589 // and the library's base address. On failure, buf[0] is set to '\0'
590 // and offset is set to -1 (if offset is non-NULL).
591 static bool dll_address_to_library_name(address addr, char* buf,
592 int buflen, int* offset);
593
594 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
595 static bool address_is_in_vm(address addr);
596
597 // Loads .dll/.so and
598 // in case of error it checks if .dll/.so was built for the
599 // same architecture as Hotspot is running on
600 static void* dll_load(const char *name, char *ebuf, int ebuflen);
601
602 // lookup symbol in a shared library
603 static void* dll_lookup(void* handle, const char* name);
604
605 // Unload library
606 static void dll_unload(void *lib);
607
608 // Callback for loaded module information
609 // Input parameters:
610 // char* module_file_name,
611 // address module_base_addr,
612 // address module_top_addr,
613 // void* param
614 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
615
616 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
617
618 // Return the handle of this process
619 static void* get_default_process_handle();
620
621 // Check for static linked agent library
622 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
623 size_t syms_len);
624
625 // Find agent entry point
626 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
627 const char *syms[], size_t syms_len);
628
629 static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
630 static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
631
632 // Print out system information; they are called by fatal error handler.
633 // Output format may be different on different platforms.
634 static void print_os_info(outputStream* st);
635 static void print_os_info_brief(outputStream* st);
636 static void print_cpu_info(outputStream* st);
637 static void pd_print_cpu_info(outputStream* st);
638 static void print_memory_info(outputStream* st);
639 static void print_dll_info(outputStream* st);
640 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
641 static void print_context(outputStream* st, void* context);
642 static void print_register_info(outputStream* st, void* context);
643 static void print_siginfo(outputStream* st, void* siginfo);
644 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
645 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
646
647 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
648 static size_t lasterror(char *buf, size_t len);
649 static int get_last_error();
650
651 // Determines whether the calling process is being debugged by a user-mode debugger.
652 static bool is_debugger_attached();
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 native Java library, loads if necessary
681 static void* native_java_library();
682
683 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
684 static void jvm_path(char *buf, jint buflen);
685
686 // Returns true if we are running in a headless jre.
687 static bool is_headless_jre();
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 // File conventions
694 static const char* file_separator();
695 static const char* line_separator();
696 static const char* path_separator();
697
698 // Init os specific system properties values
699 static void init_system_properties_values();
700
701 // IO operations, non-JVM_ version.
702 static int stat(const char* path, struct stat* sbuf);
703 static bool dir_is_empty(const char* path);
704
705 // IO operations on binary files
706 static int create_binary_file(const char* path, bool rewrite_existing);
707 static jlong current_file_offset(int fd);
708 static jlong seek_to_file_offset(int fd, jlong offset);
709
710 // Thread Local Storage
711 static int allocate_thread_local_storage();
712 static void thread_local_storage_at_put(int index, void* value);
713 static void* thread_local_storage_at(int index);
714 static void free_thread_local_storage(int index);
715
716 // Retrieve native stack frames.
717 // Parameter:
718 // stack: an array to storage stack pointers.
719 // frames: size of above array.
720 // toSkip: number of stack frames to skip at the beginning.
721 // Return: number of stack frames captured.
722 static int get_native_stack(address* stack, int size, int toSkip = 0);
723
724 // General allocation (must be MT-safe)
725 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
726 static void* malloc (size_t size, MEMFLAGS flags);
727 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
728 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
729
730 static void free (void *memblock, MEMFLAGS flags = mtNone);
731 static bool check_heap(bool force = false); // verify C heap integrity
732 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
733
734 #ifndef PRODUCT
735 static julong num_mallocs; // # of calls to malloc/realloc
736 static julong alloc_bytes; // # of bytes allocated
737 static julong num_frees; // # of calls to free
738 static julong free_bytes; // # of bytes freed
739 #endif
740
741 // SocketInterface (ex HPI SocketInterface )
742 static int socket(int domain, int type, int protocol);
743 static int socket_close(int fd);
744 static int socket_shutdown(int fd, int howto);
745 static int recv(int fd, char* buf, size_t nBytes, uint flags);
746 static int send(int fd, char* buf, size_t nBytes, uint flags);
747 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
748 static int timeout(int fd, long timeout);
749 static int listen(int fd, int count);
750 static int connect(int fd, struct sockaddr* him, socklen_t len);
751 static int bind(int fd, struct sockaddr* him, socklen_t len);
752 static int accept(int fd, struct sockaddr* him, socklen_t* len);
753 static int recvfrom(int fd, char* buf, size_t nbytes, uint flags,
754 struct sockaddr* from, socklen_t* fromlen);
755 static int get_sock_name(int fd, struct sockaddr* him, socklen_t* len);
756 static int sendto(int fd, char* buf, size_t len, uint flags,
757 struct sockaddr* to, socklen_t tolen);
758 static int socket_available(int fd, jint* pbytes);
759
760 static int get_sock_opt(int fd, int level, int optname,
761 char* optval, socklen_t* optlen);
762 static int set_sock_opt(int fd, int level, int optname,
763 const char* optval, socklen_t optlen);
764 static int get_host_name(char* name, int namelen);
765
766 static struct hostent* get_host_by_name(char* name);
767
768 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
769 static void signal_init();
770 static void signal_init_pd();
771 static void signal_notify(int signal_number);
772 static void* signal(int signal_number, void* handler);
773 static void signal_raise(int signal_number);
774 static int signal_wait();
775 static int signal_lookup();
776 static void* user_handler();
777 static void terminate_signal_thread();
778 static int sigexitnum_pd();
779
780 // random number generation
781 static long random(); // return 32bit pseudorandom number
782 static void init_random(long initval); // initialize random sequence
783
784 // Structured OS Exception support
785 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
786
787 // On Windows this will create an actual minidump, on Linux/Solaris it will simply check core dump limits
788 static void check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize);
789
790 // Get the default path to the core file
791 // Returns the length of the string
792 static int get_core_path(char* buffer, size_t bufferSize);
793
794 // JVMTI & JVM monitoring and management support
795 // The thread_cpu_time() and current_thread_cpu_time() are only
796 // supported if is_thread_cpu_time_supported() returns true.
797 // They are not supported on Solaris T1.
798
799 // Thread CPU Time - return the fast estimate on a platform
800 // On Solaris - call gethrvtime (fast) - user time only
801 // On Linux - fast clock_gettime where available - user+sys
802 // - otherwise: very slow /proc fs - user+sys
803 // On Windows - GetThreadTimes - user+sys
804 static jlong current_thread_cpu_time();
805 static jlong thread_cpu_time(Thread* t);
806
807 // Thread CPU Time with user_sys_cpu_time parameter.
808 //
809 // If user_sys_cpu_time is true, user+sys time is returned.
810 // Otherwise, only user time is returned
811 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
812 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
813
814 // Return a bunch of info about the timers.
815 // Note that the returned info for these two functions may be different
816 // on some platforms
817 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
818 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
819
820 static bool is_thread_cpu_time_supported();
821
822 // System loadavg support. Returns -1 if load average cannot be obtained.
823 static int loadavg(double loadavg[], int nelem);
824
825 // Hook for os specific jvm options that we don't want to abort on seeing
826 static bool obsolete_option(const JavaVMOption *option);
827
828 // Extensions
829 #include "runtime/os_ext.hpp"
830
831 public:
832 class CrashProtectionCallback : public StackObj {
833 public:
834 virtual void call() = 0;
835 };
836
837 // Platform dependent stuff
838 #ifdef TARGET_OS_FAMILY_linux
839 # include "os_linux.hpp"
840 # include "os_posix.hpp"
841 #endif
842 #ifdef TARGET_OS_FAMILY_solaris
843 # include "os_solaris.hpp"
844 # include "os_posix.hpp"
845 #endif
846 #ifdef TARGET_OS_FAMILY_windows
847 # include "os_windows.hpp"
848 #endif
849 #ifdef TARGET_OS_FAMILY_aix
850 # include "os_aix.hpp"
851 # include "os_posix.hpp"
852 #endif
853 #ifdef TARGET_OS_FAMILY_bsd
854 # include "os_posix.hpp"
855 # include "os_bsd.hpp"
856 #endif
857 #ifdef TARGET_OS_ARCH_linux_x86
858 # include "os_linux_x86.hpp"
859 #endif
860 #ifdef TARGET_OS_ARCH_linux_sparc
861 # include "os_linux_sparc.hpp"
862 #endif
863 #ifdef TARGET_OS_ARCH_linux_zero
864 # include "os_linux_zero.hpp"
865 #endif
866 #ifdef TARGET_OS_ARCH_solaris_x86
867 # include "os_solaris_x86.hpp"
868 #endif
869 #ifdef TARGET_OS_ARCH_solaris_sparc
870 # include "os_solaris_sparc.hpp"
871 #endif
872 #ifdef TARGET_OS_ARCH_windows_x86
873 # include "os_windows_x86.hpp"
874 #endif
875 #ifdef TARGET_OS_ARCH_linux_arm
876 # include "os_linux_arm.hpp"
877 #endif
878 #ifdef TARGET_OS_ARCH_linux_ppc
879 # include "os_linux_ppc.hpp"
880 #endif
881 #ifdef TARGET_OS_ARCH_aix_ppc
882 # include "os_aix_ppc.hpp"
883 #endif
884 #ifdef TARGET_OS_ARCH_bsd_x86
885 # include "os_bsd_x86.hpp"
886 #endif
887 #ifdef TARGET_OS_ARCH_bsd_zero
888 # include "os_bsd_zero.hpp"
889 #endif
890
891 public:
892 #ifndef PLATFORM_PRINT_NATIVE_STACK
893 // No platform-specific code for printing the native stack.
894 static bool platform_print_native_stack(outputStream* st, void* context,
895 char *buf, int buf_size) {
896 return false;
897 }
898 #endif
899
900 // debugging support (mostly used by debug.cpp but also fatal error handler)
901 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
902
903 static bool dont_yield(); // when true, JVM_Yield() is nop
904 static void print_statistics();
905
906 // Thread priority helpers (implemented in OS-specific part)
907 static OSReturn set_native_priority(Thread* thread, int native_prio);
908 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
909 static int java_to_os_priority[CriticalPriority + 1];
910 // Hint to the underlying OS that a task switch would not be good.
911 // Void return because it's a hint and can fail.
912 static void hint_no_preempt();
913
914 // Used at creation if requested by the diagnostic flag PauseAtStartup.
915 // Causes the VM to wait until an external stimulus has been applied
916 // (for Unix, that stimulus is a signal, for Windows, an external
917 // ResumeThread call)
918 static void pause();
919
920 // Builds a platform dependent Agent_OnLoad_<libname> function name
921 // which is used to find statically linked in agents.
922 static char* build_agent_function_name(const char *sym, const char *cname,
923 bool is_absolute_path);
924
925 class SuspendedThreadTaskContext {
926 public:
927 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
928 Thread* thread() const { return _thread; }
929 void* ucontext() const { return _ucontext; }
930 private:
931 Thread* _thread;
932 void* _ucontext;
933 };
934
935 class SuspendedThreadTask {
936 public:
937 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
938 virtual ~SuspendedThreadTask() {}
939 void run();
940 bool is_done() { return _done; }
941 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
942 protected:
943 private:
944 void internal_do_task();
945 Thread* _thread;
946 bool _done;
947 };
948
949 #ifndef TARGET_OS_FAMILY_windows
950 // Suspend/resume support
951 // Protocol:
952 //
953 // a thread starts in SR_RUNNING
954 //
955 // SR_RUNNING can go to
956 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
957 // SR_SUSPEND_REQUEST can go to
958 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
959 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
960 // SR_SUSPENDED can go to
961 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
962 // SR_WAKEUP_REQUEST can go to
963 // * SR_RUNNING when the stopped thread receives the signal
964 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
965 class SuspendResume {
966 public:
967 enum State {
968 SR_RUNNING,
969 SR_SUSPEND_REQUEST,
970 SR_SUSPENDED,
971 SR_WAKEUP_REQUEST
972 };
973
974 private:
975 volatile State _state;
976
977 private:
978 /* try to switch state from state "from" to state "to"
979 * returns the state set after the method is complete
980 */
981 State switch_state(State from, State to);
982
983 public:
984 SuspendResume() : _state(SR_RUNNING) { }
985
986 State state() const { return _state; }
987
988 State request_suspend() {
989 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
990 }
991
992 State cancel_suspend() {
993 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
994 }
995
996 State suspended() {
997 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
998 }
999
1000 State request_wakeup() {
1001 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
1002 }
1003
1004 State running() {
1005 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
1006 }
1007
1008 bool is_running() const {
1009 return _state == SR_RUNNING;
1010 }
1011
1012 bool is_suspend_request() const {
1013 return _state == SR_SUSPEND_REQUEST;
1014 }
1015
1016 bool is_suspended() const {
1017 return _state == SR_SUSPENDED;
1018 }
1019 };
1020 #endif
1021
1022
1023 protected:
1024 static long _rand_seed; // seed for random number generator
1025 static int _processor_count; // number of processors
1026 static int _initial_active_processor_count; // number of active processors during initialization.
1027
1028 static char* format_boot_path(const char* format_string,
1029 const char* home,
1030 int home_len,
1031 char fileSep,
1032 char pathSep);
1033 static bool set_boot_path(char fileSep, char pathSep);
1034 static char** split_path(const char* path, int* n);
1035
1036 };
1037
1038 // Note that "PAUSE" is almost always used with synchronization
1039 // so arguably we should provide Atomic::SpinPause() instead
1040 // of the global SpinPause() with C linkage.
1041 // It'd also be eligible for inlining on many platforms.
1042
1043 extern "C" int SpinPause();
1044
1045 #endif // SHARE_VM_RUNTIME_OS_HPP