Thu, 25 Sep 2008 12:50:51 -0700
6744783: HotSpot segfaults if given -XX options with an empty string argument
Reviewed-by: kamg, kvn
Contributed-by: volker.simonis@gmail.com
1 /*
2 * Copyright 1997-2008 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 // os defines the interface to operating system; this includes traditional
26 // OS services (time, I/O) as well as other functionality with system-
27 // dependent code.
29 typedef void (*dll_func)(...);
31 class Thread;
32 class JavaThread;
33 class Event;
34 class DLL;
35 class FileHandle;
36 template<class E> class GrowableArray;
38 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
40 // Platform-independent error return values from OS functions
41 enum OSReturn {
42 OS_OK = 0, // Operation was successful
43 OS_ERR = -1, // Operation failed
44 OS_INTRPT = -2, // Operation was interrupted
45 OS_TIMEOUT = -3, // Operation timed out
46 OS_NOMEM = -5, // Operation failed for lack of memory
47 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
48 };
50 enum ThreadPriority { // JLS 20.20.1-3
51 NoPriority = -1, // Initial non-priority value
52 MinPriority = 1, // Minimum priority
53 NormPriority = 5, // Normal (non-daemon) priority
54 NearMaxPriority = 9, // High priority, used for VMThread
55 MaxPriority = 10 // Highest priority, used for WatcherThread
56 // ensures that VMThread doesn't starve profiler
57 };
59 // Typedef for structured exception handling support
60 typedef void (*java_call_t)(JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
62 class os: AllStatic {
63 private:
64 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
66 static OSThread* _starting_thread;
67 static address _polling_page;
68 static volatile int32_t * _mem_serialize_page;
69 static uintptr_t _serialize_page_mask;
70 static size_t _page_sizes[page_sizes_max];
72 static void init_page_sizes(size_t default_page_size) {
73 _page_sizes[0] = default_page_size;
74 _page_sizes[1] = 0; // sentinel
75 }
77 public:
79 static void init(void); // Called before command line parsing
80 static jint init_2(void); // Called after command line parsing
82 // File names are case-insensitive on windows only
83 // Override me as needed
84 static int file_name_strcmp(const char* s1, const char* s2);
86 static bool getenv(const char* name, char* buffer, int len);
87 static bool have_special_privileges();
89 static jlong javaTimeMillis();
90 static jlong javaTimeNanos();
91 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
92 static void run_periodic_checks();
95 // Returns the elapsed time in seconds since the vm started.
96 static double elapsedTime();
98 // Returns real time in seconds since an arbitrary point
99 // in the past.
100 static bool getTimesSecs(double* process_real_time,
101 double* process_user_time,
102 double* process_system_time);
104 // Interface to the performance counter
105 static jlong elapsed_counter();
106 static jlong elapsed_frequency();
108 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
109 // It is MT safe, but not async-safe, as reading time zone
110 // information may require a lock on some platforms.
111 static char* local_time_string(char *buf, size_t buflen);
112 // Fill in buffer with current local time as an ISO-8601 string.
113 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
114 // Returns buffer, or NULL if it failed.
115 static char* iso8601_time(char* buffer, size_t buffer_length);
117 // Interface for detecting multiprocessor system
118 static inline bool is_MP() {
119 assert(_processor_count > 0, "invalid processor count");
120 return _processor_count > 1;
121 }
122 static julong available_memory();
123 static julong physical_memory();
124 static julong allocatable_physical_memory(julong size);
125 static bool is_server_class_machine();
127 // number of CPUs
128 static int processor_count() {
129 return _processor_count;
130 }
132 // Returns the number of CPUs this process is currently allowed to run on.
133 // Note that on some OSes this can change dynamically.
134 static int active_processor_count();
136 // Bind processes to processors.
137 // This is a two step procedure:
138 // first you generate a distribution of processes to processors,
139 // then you bind processes according to that distribution.
140 // Compute a distribution for number of processes to processors.
141 // Stores the processor id's into the distribution array argument.
142 // Returns true if it worked, false if it didn't.
143 static bool distribute_processes(uint length, uint* distribution);
144 // Binds the current process to a processor.
145 // Returns true if it worked, false if it didn't.
146 static bool bind_to_processor(uint processor_id);
148 // Interface for stack banging (predetect possible stack overflow for
149 // exception processing) There are guard pages, and above that shadow
150 // pages for stack overflow checking.
151 static bool uses_stack_guard_pages();
152 static bool allocate_stack_guard_pages();
153 static void bang_stack_shadow_pages();
154 static bool stack_shadow_pages_available(Thread *thread, methodHandle method);
156 // OS interface to Virtual Memory
158 // Return the default page size.
159 static int vm_page_size();
161 // Return the page size to use for a region of memory. The min_pages argument
162 // is a hint intended to limit fragmentation; it says the returned page size
163 // should be <= region_max_size / min_pages. Because min_pages is a hint,
164 // this routine may return a size larger than region_max_size / min_pages.
165 //
166 // The current implementation ignores min_pages if a larger page size is an
167 // exact multiple of both region_min_size and region_max_size. This allows
168 // larger pages to be used when doing so would not cause fragmentation; in
169 // particular, a single page can be used when region_min_size ==
170 // region_max_size == a supported page size.
171 static size_t page_size_for_region(size_t region_min_size,
172 size_t region_max_size,
173 uint min_pages);
175 // Method for tracing page sizes returned by the above method; enabled by
176 // TracePageSizes. The region_{min,max}_size parameters should be the values
177 // passed to page_size_for_region() and page_size should be the result of that
178 // call. The (optional) base and size parameters should come from the
179 // ReservedSpace base() and size() methods.
180 static void trace_page_sizes(const char* str, const size_t region_min_size,
181 const size_t region_max_size,
182 const size_t page_size,
183 const char* base = NULL,
184 const size_t size = 0) PRODUCT_RETURN;
186 static int vm_allocation_granularity();
187 static char* reserve_memory(size_t bytes, char* addr = 0,
188 size_t alignment_hint = 0);
189 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
190 static void split_reserved_memory(char *base, size_t size,
191 size_t split, bool realloc);
192 static bool commit_memory(char* addr, size_t bytes);
193 static bool commit_memory(char* addr, size_t size, size_t alignment_hint);
194 static bool uncommit_memory(char* addr, size_t bytes);
195 static bool release_memory(char* addr, size_t bytes);
197 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
198 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
199 bool is_committed = false);
201 static bool guard_memory(char* addr, size_t bytes);
202 static bool unguard_memory(char* addr, size_t bytes);
203 static char* map_memory(int fd, const char* file_name, size_t file_offset,
204 char *addr, size_t bytes, bool read_only = false,
205 bool allow_exec = false);
206 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
207 char *addr, size_t bytes, bool read_only,
208 bool allow_exec);
209 static bool unmap_memory(char *addr, size_t bytes);
210 static void free_memory(char *addr, size_t bytes);
211 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
213 // NUMA-specific interface
214 static bool numa_has_static_binding();
215 static bool numa_has_group_homing();
216 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
217 static void numa_make_global(char *addr, size_t bytes);
218 static size_t numa_get_groups_num();
219 static size_t numa_get_leaf_groups(int *ids, size_t size);
220 static bool numa_topology_changed();
221 static int numa_get_group_id();
223 // Page manipulation
224 struct page_info {
225 size_t size;
226 int lgrp_id;
227 };
228 static bool get_page_info(char *start, page_info* info);
229 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
231 static char* non_memory_address_word();
232 // reserve, commit and pin the entire memory region
233 static char* reserve_memory_special(size_t size);
234 static bool release_memory_special(char* addr, size_t bytes);
235 static bool large_page_init();
236 static size_t large_page_size();
237 static bool can_commit_large_page_memory();
238 static bool can_execute_large_page_memory();
240 // OS interface to polling page
241 static address get_polling_page() { return _polling_page; }
242 static void set_polling_page(address page) { _polling_page = page; }
243 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
244 static void make_polling_page_unreadable();
245 static void make_polling_page_readable();
247 // Routines used to serialize the thread state without using membars
248 static void serialize_thread_states();
250 // Since we write to the serialize page from every thread, we
251 // want stores to be on unique cache lines whenever possible
252 // in order to minimize CPU cross talk. We pre-compute the
253 // amount to shift the thread* to make this offset unique to
254 // each thread.
255 static int get_serialize_page_shift_count() {
256 return SerializePageShiftCount;
257 }
259 static void set_serialize_page_mask(uintptr_t mask) {
260 _serialize_page_mask = mask;
261 }
263 static unsigned int get_serialize_page_mask() {
264 return _serialize_page_mask;
265 }
267 static void set_memory_serialize_page(address page);
269 static address get_memory_serialize_page() {
270 return (address)_mem_serialize_page;
271 }
273 static inline void write_memory_serialize_page(JavaThread *thread) {
274 uintptr_t page_offset = ((uintptr_t)thread >>
275 get_serialize_page_shift_count()) &
276 get_serialize_page_mask();
277 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
278 }
280 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
281 address thr_addr;
282 if (UseMembar) return false;
283 // Calculate thread specific address
284 if (thread == NULL) return false;
285 // TODO-FIXME: some platforms mask off faulting addresses to the base pagesize.
286 // Instead of using a test for equality we should probably use something
287 // of the form:
288 // return ((_mem_serialize_page ^ addr) & -pagesize) == 0
289 //
290 thr_addr = (address)(((uintptr_t)thread >>
291 get_serialize_page_shift_count()) &
292 get_serialize_page_mask()) + (uintptr_t)_mem_serialize_page;
293 return (thr_addr == addr);
294 }
296 static void block_on_serialize_page_trap();
298 // threads
300 enum ThreadType {
301 vm_thread,
302 cgc_thread, // Concurrent GC thread
303 pgc_thread, // Parallel GC thread
304 java_thread,
305 compiler_thread,
306 watcher_thread
307 };
309 static bool create_thread(Thread* thread,
310 ThreadType thr_type,
311 size_t stack_size = 0);
312 static bool create_main_thread(JavaThread* thread);
313 static bool create_attached_thread(JavaThread* thread);
314 static void pd_start_thread(Thread* thread);
315 static void start_thread(Thread* thread);
317 static void initialize_thread();
318 static void free_thread(OSThread* osthread);
320 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
321 static intx current_thread_id();
322 static int current_process_id();
323 // hpi::read for calls from non native state
324 // For performance, hpi::read is only callable from _thread_in_native
325 static size_t read(int fd, void *buf, unsigned int nBytes);
326 static int sleep(Thread* thread, jlong ms, bool interruptable);
327 static int naked_sleep();
328 static void infinite_sleep(); // never returns, use with CAUTION
329 static void yield(); // Yields to all threads with same priority
330 enum YieldResult {
331 YIELD_SWITCHED = 1, // caller descheduled, other ready threads exist & ran
332 YIELD_NONEREADY = 0, // No other runnable/ready threads.
333 // platform-specific yield return immediately
334 YIELD_UNKNOWN = -1 // Unknown: platform doesn't support _SWITCHED or _NONEREADY
335 // YIELD_SWITCHED and YIELD_NONREADY imply the platform supports a "strong"
336 // yield that can be used in lieu of blocking.
337 } ;
338 static YieldResult NakedYield () ;
339 static void yield_all(int attempts = 0); // Yields to all other threads including lower priority
340 static void loop_breaker(int attempts); // called from within tight loops to possibly influence time-sharing
341 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
342 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
344 static void interrupt(Thread* thread);
345 static bool is_interrupted(Thread* thread, bool clear_interrupted);
347 static int pd_self_suspend_thread(Thread* thread);
349 static ExtendedPC fetch_frame_from_context(void* ucVoid, intptr_t** sp, intptr_t** fp);
350 static frame fetch_frame_from_context(void* ucVoid);
352 static ExtendedPC get_thread_pc(Thread *thread);
353 static void breakpoint();
355 static address current_stack_pointer();
356 static address current_stack_base();
357 static size_t current_stack_size();
359 static int message_box(const char* title, const char* message);
360 static char* do_you_want_to_debug(const char* message);
362 // run cmd in a separate process and return its exit code; or -1 on failures
363 static int fork_and_exec(char *cmd);
365 // Set file to send error reports.
366 static void set_error_file(const char *logfile);
368 // os::exit() is merged with vm_exit()
369 // static void exit(int num);
371 // Terminate the VM, but don't exit the process
372 static void shutdown();
374 // Terminate with an error. Default is to generate a core file on platforms
375 // that support such things. This calls shutdown() and then aborts.
376 static void abort(bool dump_core = true);
378 // Die immediately, no exit hook, no abort hook, no cleanup.
379 static void die();
381 // Reading directories.
382 static DIR* opendir(const char* dirname);
383 static int readdir_buf_size(const char *path);
384 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
385 static int closedir(DIR* dirp);
387 // Dynamic library extension
388 static const char* dll_file_extension();
390 static const char* get_temp_directory();
391 static const char* get_current_directory(char *buf, int buflen);
393 // Builds a platform-specific full library path given a ld path and lib name
394 static void dll_build_name(char* buffer, size_t size,
395 const char* pathname, const char* fname);
397 // Symbol lookup, find nearest function name; basically it implements
398 // dladdr() for all platforms. Name of the nearest function is copied
399 // to buf. Distance from its base address is returned as offset.
400 // If function name is not found, buf[0] is set to '\0' and offset is
401 // set to -1.
402 static bool dll_address_to_function_name(address addr, char* buf,
403 int buflen, int* offset);
405 // Locate DLL/DSO. On success, full path of the library is copied to
406 // buf, and offset is set to be the distance between addr and the
407 // library's base address. On failure, buf[0] is set to '\0' and
408 // offset is set to -1.
409 static bool dll_address_to_library_name(address addr, char* buf,
410 int buflen, int* offset);
412 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
413 static bool address_is_in_vm(address addr);
415 // Loads .dll/.so and
416 // in case of error it checks if .dll/.so was built for the
417 // same architecture as Hotspot is running on
418 static void* dll_load(const char *name, char *ebuf, int ebuflen);
420 // lookup symbol in a shared library
421 static void* dll_lookup(void* handle, const char* name);
423 // Print out system information; they are called by fatal error handler.
424 // Output format may be different on different platforms.
425 static void print_os_info(outputStream* st);
426 static void print_cpu_info(outputStream* st);
427 static void print_memory_info(outputStream* st);
428 static void print_dll_info(outputStream* st);
429 static void print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len);
430 static void print_context(outputStream* st, void* context);
431 static void print_siginfo(outputStream* st, void* siginfo);
432 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
433 static void print_date_and_time(outputStream* st);
435 // The following two functions are used by fatal error handler to trace
436 // native (C) frames. They are not part of frame.hpp/frame.cpp because
437 // frame.hpp/cpp assume thread is JavaThread, and also because different
438 // OS/compiler may have different convention or provide different API to
439 // walk C frames.
440 //
441 // We don't attempt to become a debugger, so we only follow frames if that
442 // does not require a lookup in the unwind table, which is part of the binary
443 // file but may be unsafe to read after a fatal error. So on x86, we can
444 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
445 // possible to walk C stack without having the unwind table.
446 static bool is_first_C_frame(frame *fr);
447 static frame get_sender_for_C_frame(frame *fr);
449 // return current frame. pc() and sp() are set to NULL on failure.
450 static frame current_frame();
452 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
454 // returns a string to describe the exception/signal;
455 // returns NULL if exception_code is not an OS exception/signal.
456 static const char* exception_name(int exception_code, char* buf, size_t buflen);
458 // Returns native Java library, loads if necessary
459 static void* native_java_library();
461 // Fills in path to jvm.dll/libjvm.so (this info used to find hpi).
462 static void jvm_path(char *buf, jint buflen);
464 // JNI names
465 static void print_jni_name_prefix_on(outputStream* st, int args_size);
466 static void print_jni_name_suffix_on(outputStream* st, int args_size);
468 // File conventions
469 static const char* file_separator();
470 static const char* line_separator();
471 static const char* path_separator();
473 // Init os specific system properties values
474 static void init_system_properties_values();
476 // IO operations, non-JVM_ version.
477 static int stat(const char* path, struct stat* sbuf);
478 static bool dir_is_empty(const char* path);
480 // IO operations on binary files
481 static int create_binary_file(const char* path, bool rewrite_existing);
482 static jlong current_file_offset(int fd);
483 static jlong seek_to_file_offset(int fd, jlong offset);
485 // Thread Local Storage
486 static int allocate_thread_local_storage();
487 static void thread_local_storage_at_put(int index, void* value);
488 static void* thread_local_storage_at(int index);
489 static void free_thread_local_storage(int index);
491 // General allocation (must be MT-safe)
492 static void* malloc (size_t size);
493 static void* realloc (void *memblock, size_t size);
494 static void free (void *memblock);
495 static bool check_heap(bool force = false); // verify C heap integrity
496 static char* strdup(const char *); // Like strdup
498 #ifndef PRODUCT
499 static int num_mallocs; // # of calls to malloc/realloc
500 static size_t alloc_bytes; // # of bytes allocated
501 static int num_frees; // # of calls to free
502 #endif
504 // Printing 64 bit integers
505 static const char* jlong_format_specifier();
506 static const char* julong_format_specifier();
508 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
509 static void signal_init();
510 static void signal_init_pd();
511 static void signal_notify(int signal_number);
512 static void* signal(int signal_number, void* handler);
513 static void signal_raise(int signal_number);
514 static int signal_wait();
515 static int signal_lookup();
516 static void* user_handler();
517 static void terminate_signal_thread();
518 static int sigexitnum_pd();
520 // random number generation
521 static long random(); // return 32bit pseudorandom number
522 static void init_random(long initval); // initialize random sequence
524 // Structured OS Exception support
525 static void os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread);
527 // JVMTI & JVM monitoring and management support
528 // The thread_cpu_time() and current_thread_cpu_time() are only
529 // supported if is_thread_cpu_time_supported() returns true.
530 // They are not supported on Solaris T1.
532 // Thread CPU Time - return the fast estimate on a platform
533 // On Solaris - call gethrvtime (fast) - user time only
534 // On Linux - fast clock_gettime where available - user+sys
535 // - otherwise: very slow /proc fs - user+sys
536 // On Windows - GetThreadTimes - user+sys
537 static jlong current_thread_cpu_time();
538 static jlong thread_cpu_time(Thread* t);
540 // Thread CPU Time with user_sys_cpu_time parameter.
541 //
542 // If user_sys_cpu_time is true, user+sys time is returned.
543 // Otherwise, only user time is returned
544 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
545 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
547 // Return a bunch of info about the timers.
548 // Note that the returned info for these two functions may be different
549 // on some platforms
550 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
551 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
553 static bool is_thread_cpu_time_supported();
555 // System loadavg support. Returns -1 if load average cannot be obtained.
556 static int loadavg(double loadavg[], int nelem);
558 // Hook for os specific jvm options that we don't want to abort on seeing
559 static bool obsolete_option(const JavaVMOption *option);
561 // Platform dependent stuff
562 #include "incls/_os_pd.hpp.incl"
564 // debugging support (mostly used by debug.cpp)
565 static bool find(address pc) PRODUCT_RETURN0; // OS specific function to make sense out of an address
567 static bool dont_yield(); // when true, JVM_Yield() is nop
568 static void print_statistics();
570 // Thread priority helpers (implemented in OS-specific part)
571 static OSReturn set_native_priority(Thread* thread, int native_prio);
572 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
573 static int java_to_os_priority[MaxPriority + 1];
574 // Hint to the underlying OS that a task switch would not be good.
575 // Void return because it's a hint and can fail.
576 static void hint_no_preempt();
578 // Used at creation if requested by the diagnostic flag PauseAtStartup.
579 // Causes the VM to wait until an external stimulus has been applied
580 // (for Unix, that stimulus is a signal, for Windows, an external
581 // ResumeThread call)
582 static void pause();
584 protected:
585 static long _rand_seed; // seed for random number generator
586 static int _processor_count; // number of processors
588 static char* format_boot_path(const char* format_string,
589 const char* home,
590 int home_len,
591 char fileSep,
592 char pathSep);
593 static bool set_boot_path(char fileSep, char pathSep);
594 };
596 // Note that "PAUSE" is almost always used with synchronization
597 // so arguably we should provide Atomic::SpinPause() instead
598 // of the global SpinPause() with C linkage.
599 // It'd also be eligible for inlining on many platforms.
601 extern "C" int SpinPause () ;
602 extern "C" int SafeFetch32 (int * adr, int errValue) ;
603 extern "C" intptr_t SafeFetchN (intptr_t * adr, intptr_t errValue) ;