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authorEric Andersen <andersen@codepoet.org>2002-02-20 09:18:50 +0000
committerEric Andersen <andersen@codepoet.org>2002-02-20 09:18:50 +0000
commite356ea321c8098cf1a83a67e27d64c44de08a298 (patch)
tree8be9273fb8f0e6acab47a9e09552cfbea5400b31 /libpthread/linuxthreads/join.c
parent07ebf927b17572d92e785533d6e8ac1668cc57c6 (diff)
Merge in the pthread library. This is the linuxthreads library taken from
glibc 2.1.3 and ported to work with uClibc by Stefan Soucek and Erik Andersen (me). Stefan has hacked things up such that linuxthreads runs on MMU-less systems (tested only on arm-nommu). Erik cleaned things up and made it work properly as a shared library. -Erik
Diffstat (limited to 'libpthread/linuxthreads/join.c')
-rw-r--r--libpthread/linuxthreads/join.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/join.c b/libpthread/linuxthreads/join.c
new file mode 100644
index 000000000..ccb11b124
--- /dev/null
+++ b/libpthread/linuxthreads/join.c
@@ -0,0 +1,213 @@
+/* Linuxthreads - a simple clone()-based implementation of Posix */
+/* threads for Linux. */
+/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
+/* */
+/* This program is free software; you can redistribute it and/or */
+/* modify it under the terms of the GNU Library General Public License */
+/* as published by the Free Software Foundation; either version 2 */
+/* of the License, or (at your option) any later version. */
+/* */
+/* This program is distributed in the hope that it will be useful, */
+/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
+/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
+/* GNU Library General Public License for more details. */
+
+/* Thread termination and joining */
+
+#include <errno.h>
+#include <sched.h>
+#include <unistd.h>
+#include "pthread.h"
+#include "internals.h"
+#include "spinlock.h"
+#include "restart.h"
+#include "debug.h" /* PDEBUG, added by StS */
+
+void pthread_exit(void * retval)
+{
+ pthread_descr self = thread_self();
+ pthread_descr joining;
+ struct pthread_request request;
+PDEBUG("self=%p, pid=%d\n", self, self->p_pid);
+
+ /* Reset the cancellation flag to avoid looping if the cleanup handlers
+ contain cancellation points */
+ THREAD_SETMEM(self, p_canceled, 0);
+ /* Call cleanup functions and destroy the thread-specific data */
+ __pthread_perform_cleanup();
+ __pthread_destroy_specifics();
+ /* Store return value */
+ __pthread_lock(THREAD_GETMEM(self, p_lock), self);
+ THREAD_SETMEM(self, p_retval, retval);
+ /* Say that we've terminated */
+ THREAD_SETMEM(self, p_terminated, 1);
+ /* See whether we have to signal the death. */
+ if (THREAD_GETMEM(self, p_report_events))
+ {
+ /* See whether TD_DEATH is in any of the mask. */
+ int idx = __td_eventword (TD_DEATH);
+ uint32_t mask = __td_eventmask (TD_DEATH);
+
+ if ((mask & (__pthread_threads_events.event_bits[idx]
+ | THREAD_GETMEM(self,
+ p_eventbuf.eventmask).event_bits[idx]))
+ != 0)
+ {
+ /* Yep, we have to signal the death. */
+ THREAD_SETMEM(self, p_eventbuf.eventnum, TD_DEATH);
+ THREAD_SETMEM(self, p_eventbuf.eventdata, self);
+ __pthread_last_event = self;
+
+ /* Now call the function to signal the event. */
+ __linuxthreads_death_event();
+ }
+ }
+ /* See if someone is joining on us */
+ joining = THREAD_GETMEM(self, p_joining);
+PDEBUG("joining = %p, pid=%d\n", joining, joining->p_pid);
+ __pthread_unlock(THREAD_GETMEM(self, p_lock));
+ /* Restart joining thread if any */
+ if (joining != NULL) restart(joining);
+ /* If this is the initial thread, block until all threads have terminated.
+ If another thread calls exit, we'll be terminated from our signal
+ handler. */
+ if (self == __pthread_main_thread && __pthread_manager_request >= 0) {
+ request.req_thread = self;
+ request.req_kind = REQ_MAIN_THREAD_EXIT;
+ __libc_write(__pthread_manager_request, (char *)&request, sizeof(request));
+ suspend(self);
+ }
+ /* Exit the process (but don't flush stdio streams, and don't run
+ atexit functions). */
+ _exit(0);
+}
+
+/* Function called by pthread_cancel to remove the thread from
+ waiting on a condition variable queue. */
+
+static int join_extricate_func(void *obj, pthread_descr th)
+{
+ volatile pthread_descr self = thread_self();
+ pthread_handle handle = obj;
+ pthread_descr jo;
+ int did_remove = 0;
+
+ __pthread_lock(&handle->h_lock, self);
+ jo = handle->h_descr;
+ did_remove = jo->p_joining != NULL;
+ jo->p_joining = NULL;
+ __pthread_unlock(&handle->h_lock);
+
+ return did_remove;
+}
+
+int pthread_join(pthread_t thread_id, void ** thread_return)
+{
+ volatile pthread_descr self = thread_self();
+ struct pthread_request request;
+ pthread_handle handle = thread_handle(thread_id);
+ pthread_descr th;
+ pthread_extricate_if extr;
+ int already_canceled = 0;
+PDEBUG("\n");
+
+ /* Set up extrication interface */
+ extr.pu_object = handle;
+ extr.pu_extricate_func = join_extricate_func;
+
+ __pthread_lock(&handle->h_lock, self);
+ if (invalid_handle(handle, thread_id)) {
+ __pthread_unlock(&handle->h_lock);
+ return ESRCH;
+ }
+ th = handle->h_descr;
+ if (th == self) {
+ __pthread_unlock(&handle->h_lock);
+ return EDEADLK;
+ }
+ /* If detached or already joined, error */
+ if (th->p_detached || th->p_joining != NULL) {
+ __pthread_unlock(&handle->h_lock);
+ return EINVAL;
+ }
+ /* If not terminated yet, suspend ourselves. */
+ if (! th->p_terminated) {
+ /* Register extrication interface */
+ __pthread_set_own_extricate_if(self, &extr);
+ if (!(THREAD_GETMEM(self, p_canceled)
+ && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE))
+ th->p_joining = self;
+ else
+ already_canceled = 1;
+ __pthread_unlock(&handle->h_lock);
+
+ if (already_canceled) {
+ __pthread_set_own_extricate_if(self, 0);
+ pthread_exit(PTHREAD_CANCELED);
+ }
+
+PDEBUG("before suspend\n");
+ suspend(self);
+PDEBUG("after suspend\n");
+ /* Deregister extrication interface */
+ __pthread_set_own_extricate_if(self, 0);
+
+ /* This is a cancellation point */
+ if (THREAD_GETMEM(self, p_woken_by_cancel)
+ && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE) {
+ THREAD_SETMEM(self, p_woken_by_cancel, 0);
+ pthread_exit(PTHREAD_CANCELED);
+ }
+ __pthread_lock(&handle->h_lock, self);
+ }
+ /* Get return value */
+ if (thread_return != NULL) *thread_return = th->p_retval;
+ __pthread_unlock(&handle->h_lock);
+ /* Send notification to thread manager */
+ if (__pthread_manager_request >= 0) {
+ request.req_thread = self;
+ request.req_kind = REQ_FREE;
+ request.req_args.free.thread_id = thread_id;
+ __libc_write(__pthread_manager_request,
+ (char *) &request, sizeof(request));
+ }
+ return 0;
+}
+
+int pthread_detach(pthread_t thread_id)
+{
+ int terminated;
+ struct pthread_request request;
+ pthread_handle handle = thread_handle(thread_id);
+ pthread_descr th;
+
+ __pthread_lock(&handle->h_lock, NULL);
+ if (invalid_handle(handle, thread_id)) {
+ __pthread_unlock(&handle->h_lock);
+ return ESRCH;
+ }
+ th = handle->h_descr;
+ /* If already detached, error */
+ if (th->p_detached) {
+ __pthread_unlock(&handle->h_lock);
+ return EINVAL;
+ }
+ /* If already joining, don't do anything. */
+ if (th->p_joining != NULL) {
+ __pthread_unlock(&handle->h_lock);
+ return 0;
+ }
+ /* Mark as detached */
+ th->p_detached = 1;
+ terminated = th->p_terminated;
+ __pthread_unlock(&handle->h_lock);
+ /* If already terminated, notify thread manager to reclaim resources */
+ if (terminated && __pthread_manager_request >= 0) {
+ request.req_thread = thread_self();
+ request.req_kind = REQ_FREE;
+ request.req_args.free.thread_id = thread_id;
+ __libc_write(__pthread_manager_request,
+ (char *) &request, sizeof(request));
+ }
+ return 0;
+}