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 "pthread_internal.h"
30 
31 #include <errno.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <sys/mman.h>
35 
36 #include "private/bionic_futex.h"
37 #include "private/bionic_tls.h"
38 #include "private/libc_logging.h"
39 #include "private/ScopedPthreadMutexLocker.h"
40 
41 static pthread_internal_t* g_thread_list = NULL;
42 static pthread_mutex_t g_thread_list_lock = PTHREAD_MUTEX_INITIALIZER;
43 
__pthread_internal_add(pthread_internal_t * thread)44 pthread_t __pthread_internal_add(pthread_internal_t* thread) {
45   ScopedPthreadMutexLocker locker(&g_thread_list_lock);
46 
47   // We insert at the head.
48   thread->next = g_thread_list;
49   thread->prev = NULL;
50   if (thread->next != NULL) {
51     thread->next->prev = thread;
52   }
53   g_thread_list = thread;
54   return reinterpret_cast<pthread_t>(thread);
55 }
56 
__pthread_internal_remove(pthread_internal_t * thread)57 void __pthread_internal_remove(pthread_internal_t* thread) {
58   ScopedPthreadMutexLocker locker(&g_thread_list_lock);
59 
60   if (thread->next != NULL) {
61     thread->next->prev = thread->prev;
62   }
63   if (thread->prev != NULL) {
64     thread->prev->next = thread->next;
65   } else {
66     g_thread_list = thread->next;
67   }
68 }
69 
__pthread_internal_free(pthread_internal_t * thread)70 static void __pthread_internal_free(pthread_internal_t* thread) {
71   if (thread->mmap_size != 0) {
72     // Free mapped space, including thread stack and pthread_internal_t.
73     munmap(thread->attr.stack_base, thread->mmap_size);
74   }
75 }
76 
__pthread_internal_remove_and_free(pthread_internal_t * thread)77 void __pthread_internal_remove_and_free(pthread_internal_t* thread) {
78   __pthread_internal_remove(thread);
79   __pthread_internal_free(thread);
80 }
81 
__pthread_internal_find(pthread_t thread_id)82 pthread_internal_t* __pthread_internal_find(pthread_t thread_id) {
83   pthread_internal_t* thread = reinterpret_cast<pthread_internal_t*>(thread_id);
84 
85   // check if thread is pthread_self() before acquiring the lock
86   if (thread == __get_thread()) {
87     return thread;
88   }
89 
90   ScopedPthreadMutexLocker locker(&g_thread_list_lock);
91 
92   for (pthread_internal_t* t = g_thread_list; t != NULL; t = t->next) {
93     if (t == thread) {
94       return thread;
95     }
96   }
97   return NULL;
98 }
99