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_futex.h" 32#include "pthread_accessor.h" 33 34int pthread_join(pthread_t t, void** return_value) { 35 if (t == pthread_self()) { 36 return EDEADLK; 37 } 38 39 pid_t tid; 40 volatile int* tid_ptr; 41 { 42 pthread_accessor thread(t); 43 if (thread.get() == NULL) { 44 return ESRCH; 45 } 46 47 if ((thread->attr.flags & PTHREAD_ATTR_FLAG_DETACHED) != 0) { 48 return EINVAL; 49 } 50 51 if ((thread->attr.flags & PTHREAD_ATTR_FLAG_JOINED) != 0) { 52 return EINVAL; 53 } 54 55 // Okay, looks like we can signal our intention to join. 56 thread->attr.flags |= PTHREAD_ATTR_FLAG_JOINED; 57 tid = thread->tid; 58 tid_ptr = &thread->tid; 59 } 60 61 // We set the PTHREAD_ATTR_FLAG_JOINED flag with the lock held, 62 // so no one is going to remove this thread except us. 63 64 // Wait for the thread to actually exit, if it hasn't already. 65 while (*tid_ptr != 0) { 66 __futex_wait(tid_ptr, tid, NULL); 67 } 68 69 // Take the lock again so we can pull the thread's return value 70 // and remove the thread from the list. 71 pthread_accessor thread(t); 72 73 if (return_value) { 74 *return_value = thread->return_value; 75 } 76 77 _pthread_internal_remove_locked(thread.get()); 78 return 0; 79} 80