2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 #include "namespace.h"
34 #ifdef _PTHREAD_FORCED_UNWIND
40 #include <sys/types.h>
41 #include <sys/signalvar.h>
42 #include "un-namespace.h"
44 #include "libc_private.h"
45 #include "thr_private.h"
47 void _pthread_exit(void *status);
49 static void exit_thread(void) __dead2;
51 __weak_reference(_pthread_exit, pthread_exit);
53 #ifdef _PTHREAD_FORCED_UNWIND
55 static void thread_unwind(void) __dead2;
57 static void thread_uw_init(void);
58 static _Unwind_Reason_Code thread_unwind_stop(int version,
59 _Unwind_Action actions,
60 _Unwind_Exception_Class exc_class,
61 struct _Unwind_Exception *exc_obj,
62 struct _Unwind_Context *context, void *stop_parameter);
63 /* unwind library pointers */
64 static _Unwind_Reason_Code (*uwl_forcedunwind)(struct _Unwind_Exception *,
65 _Unwind_Stop_Fn, void *);
66 static _Unwind_Word (*uwl_getcfa)(struct _Unwind_Context *);
71 static int inited = 0;
74 void *forcedunwind, *getcfa;
78 handle = RTLD_DEFAULT;
79 if ((forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind")) != NULL) {
80 if (dladdr(forcedunwind, &dlinfo)) {
82 * Make sure the address is always valid by holding the library,
83 * also assume functions are in same library.
85 if ((handle = dlopen(dlinfo.dli_fname, RTLD_LAZY)) != NULL) {
86 forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind");
87 getcfa = dlsym(handle, "_Unwind_GetCFA");
88 if (forcedunwind != NULL && getcfa != NULL) {
90 atomic_store_rel_ptr((volatile void *)&uwl_forcedunwind,
91 (uintptr_t)forcedunwind);
102 _Unwind_ForcedUnwind(struct _Unwind_Exception *ex, _Unwind_Stop_Fn stop_func,
105 return (*uwl_forcedunwind)(ex, stop_func, stop_arg);
109 _Unwind_GetCFA(struct _Unwind_Context *context)
111 return (*uwl_getcfa)(context);
114 #pragma weak _Unwind_GetCFA
115 #pragma weak _Unwind_ForcedUnwind
119 thread_unwind_cleanup(_Unwind_Reason_Code code, struct _Unwind_Exception *e)
122 * Specification said that _Unwind_Resume should not be used here,
123 * instead, user should rethrow the exception. For C++ user, they
124 * should put "throw" sentence in catch(...) block.
126 PANIC("exception should be rethrown");
129 static _Unwind_Reason_Code
130 thread_unwind_stop(int version, _Unwind_Action actions,
131 _Unwind_Exception_Class exc_class,
132 struct _Unwind_Exception *exc_obj,
133 struct _Unwind_Context *context, void *stop_parameter)
135 struct pthread *curthread = _get_curthread();
136 struct pthread_cleanup *cur;
140 /* XXX assume stack grows down to lower address */
142 cfa = _Unwind_GetCFA(context);
143 if (actions & _UA_END_OF_STACK ||
144 cfa >= (uintptr_t)curthread->unwind_stackend) {
148 while ((cur = curthread->cleanup) != NULL &&
149 (done || (uintptr_t)cur <= cfa)) {
150 __pthread_cleanup_pop_imp(1);
154 exit_thread(); /* Never return! */
156 return (_URC_NO_REASON);
162 struct pthread *curthread = _get_curthread();
164 curthread->ex.exception_class = 0;
165 curthread->ex.exception_cleanup = thread_unwind_cleanup;
166 _Unwind_ForcedUnwind(&curthread->ex, thread_unwind_stop, NULL);
167 PANIC("_Unwind_ForcedUnwind returned");
173 _thread_exit(const char *fname, int lineno, const char *msg)
176 /* Write an error message to the standard error file descriptor: */
178 "Fatal error '%s' at line %d in file %s (errno = %d)\n",
179 msg, lineno, fname, errno);
185 _pthread_exit(void *status)
187 _pthread_exit_mask(status, NULL);
191 _pthread_exit_mask(void *status, sigset_t *mask)
193 struct pthread *curthread = _get_curthread();
195 /* Check if this thread is already in the process of exiting: */
196 if (curthread->cancelling) {
198 snprintf(msg, sizeof(msg), "Thread %p has called "
199 "pthread_exit() from a destructor. POSIX 1003.1 "
200 "1996 s16.2.5.2 does not allow this!", curthread);
204 /* Flag this thread as exiting. */
205 curthread->cancelling = 1;
206 curthread->no_cancel = 1;
207 curthread->cancel_async = 0;
208 curthread->cancel_point = 0;
210 __sys_sigprocmask(SIG_SETMASK, mask, NULL);
211 if (curthread->unblock_sigcancel) {
214 curthread->unblock_sigcancel = 0;
216 SIGADDSET(set, SIGCANCEL);
217 __sys_sigprocmask(SIG_UNBLOCK, mask, NULL);
220 /* Save the return value: */
221 curthread->ret = status;
222 #ifdef _PTHREAD_FORCED_UNWIND
225 if (uwl_forcedunwind != NULL) {
229 if (_Unwind_ForcedUnwind != NULL) {
235 while (curthread->cleanup != NULL) {
236 __pthread_cleanup_pop_imp(1);
242 while (curthread->cleanup != NULL) {
243 __pthread_cleanup_pop_imp(1);
247 #endif /* _PTHREAD_FORCED_UNWIND */
253 struct pthread *curthread = _get_curthread();
255 /* Check if there is thread specific data: */
256 if (curthread->specific != NULL) {
257 /* Run the thread-specific data destructors: */
258 _thread_cleanupspecific();
261 if (!_thr_isthreaded())
264 if (atomic_fetchadd_int(&_thread_active_threads, -1) == 1) {
269 /* Tell malloc that the thread is exiting. */
270 _malloc_thread_cleanup();
273 curthread->state = PS_DEAD;
274 if (curthread->flags & THR_FLAGS_NEED_SUSPEND) {
276 _thr_umtx_wake(&curthread->cycle, INT_MAX, 0);
279 * Thread was created with initial refcount 1, we drop the
280 * reference count to allow it to be garbage collected.
282 curthread->refcount--;
283 _thr_try_gc(curthread, curthread); /* thread lock released */
285 if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH))
286 _thr_report_death(curthread);
288 #if defined(_PTHREADS_INVARIANTS)
289 if (THR_IN_CRITICAL(curthread))
290 PANIC("thread exits with resources held!");
293 * Kernel will do wakeup at the address, so joiner thread
294 * will be resumed if it is sleeping at the address.
296 thr_exit(&curthread->tid);
297 PANIC("thr_exit() returned");