platform_bionic/libc/bionic/pthread_detach.cpp
Yabin Cui 58cf31b506 Make pthread join_state not protected by g_thread_list_lock.
1. Move the representation of thread join_state from pthread.attr.flag
   to pthread.join_state. This clarifies thread state change.
2. Use atomic operations for pthread.join_state. So we don't need to
   protect it by g_thread_list_lock. g_thread_list_lock will be reduced
   to only protect g_thread_list or even removed in further changes.

Bug: 19636317
Change-Id: I31fb143a7c69508c7287307dd3b0776993ec0f43
2015-03-12 21:39:49 -07:00

55 lines
2.2 KiB
C++

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <errno.h>
#include <pthread.h>
#include "pthread_accessor.h"
int pthread_detach(pthread_t t) {
{
pthread_accessor thread(t);
if (thread.get() == NULL) {
return ESRCH;
}
ThreadJoinState old_state = THREAD_NOT_JOINED;
while (old_state == THREAD_NOT_JOINED &&
!atomic_compare_exchange_weak(&thread->join_state, &old_state, THREAD_DETACHED)) {
}
switch (old_state) {
case THREAD_NOT_JOINED: return 0;
case THREAD_JOINED: return 0; // Already being joined; silently do nothing, like glibc.
case THREAD_DETACHED: return THREAD_DETACHED;
case THREAD_EXITED_NOT_JOINED: // Call pthread_join out of scope of pthread_accessor.
}
}
// The thread is in THREAD_EXITED_NOT_JOINED, use pthread_join to clean it up.
return pthread_join(t, NULL);
}