1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <errno.h> 30 31 #include "private/bionic_defs.h" 32 #include "private/bionic_futex.h" 33 #include "pthread_internal.h" 34 35 __BIONIC_WEAK_FOR_NATIVE_BRIDGE 36 int pthread_join(pthread_t t, void** return_value) { 37 if (t == pthread_self()) { 38 return EDEADLK; 39 } 40 41 pthread_internal_t* thread = __pthread_internal_find(t); 42 if (thread == NULL) { 43 return ESRCH; 44 } 45 46 ThreadJoinState old_state = THREAD_NOT_JOINED; 47 while ((old_state == THREAD_NOT_JOINED || old_state == THREAD_EXITED_NOT_JOINED) && 48 !atomic_compare_exchange_weak(&thread->join_state, &old_state, THREAD_JOINED)) { 49 } 50 51 if (old_state == THREAD_DETACHED || old_state == THREAD_JOINED) { 52 return EINVAL; 53 } 54 55 pid_t tid = thread->tid; 56 volatile int* tid_ptr = &thread->tid; 57 58 // We set thread->join_state to THREAD_JOINED with atomic operation, 59 // so no one is going to remove this thread except us. 60 61 // Wait for the thread to actually exit, if it hasn't already. 62 while (*tid_ptr != 0) { 63 __futex_wait(tid_ptr, tid, NULL); 64 } 65 66 if (return_value) { 67 *return_value = thread->return_value; 68 } 69 70 __pthread_internal_remove_and_free(thread); 71 return 0; 72 } 73
