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 #ifndef _PTHREAD_INTERNAL_H_
29 #define _PTHREAD_INTERNAL_H_
30 
31 #include <pthread.h>
32 #include <stdatomic.h>
33 
34 #include "private/bionic_tls.h"
35 
36 /* Has the thread been detached by a pthread_join or pthread_detach call? */
37 #define PTHREAD_ATTR_FLAG_DETACHED 0x00000001
38 
39 /* Has the thread been joined by another thread? */
40 #define PTHREAD_ATTR_FLAG_JOINED 0x00000002
41 
42 struct pthread_key_data_t {
43   uintptr_t seq; // Use uintptr_t just for alignment, as we use pointer below.
44   void* data;
45 };
46 
47 enum ThreadJoinState {
48   THREAD_NOT_JOINED,
49   THREAD_EXITED_NOT_JOINED,
50   THREAD_JOINED,
51   THREAD_DETACHED
52 };
53 
54 struct pthread_internal_t {
55   struct pthread_internal_t* next;
56   struct pthread_internal_t* prev;
57 
58   pid_t tid;
59 
60  private:
61   pid_t cached_pid_;
62 
63  public:
invalidate_cached_pidpthread_internal_t64   pid_t invalidate_cached_pid() {
65     pid_t old_value;
66     get_cached_pid(&old_value);
67     set_cached_pid(0);
68     return old_value;
69   }
70 
set_cached_pidpthread_internal_t71   void set_cached_pid(pid_t value) {
72     cached_pid_ = value;
73   }
74 
get_cached_pidpthread_internal_t75   bool get_cached_pid(pid_t* cached_pid) {
76     *cached_pid = cached_pid_;
77     return (*cached_pid != 0);
78   }
79 
80   pthread_attr_t attr;
81 
82   _Atomic(ThreadJoinState) join_state;
83 
84   __pthread_cleanup_t* cleanup_stack;
85 
86   void* (*start_routine)(void*);
87   void* start_routine_arg;
88   void* return_value;
89 
90   void* alternate_signal_stack;
91 
92   pthread_mutex_t startup_handshake_mutex;
93 
94   size_t mmap_size;
95 
96   void* tls[BIONIC_TLS_SLOTS];
97 
98   pthread_key_data_t key_data[BIONIC_PTHREAD_KEY_COUNT];
99 
100   /*
101    * The dynamic linker implements dlerror(3), which makes it hard for us to implement this
102    * per-thread buffer by simply using malloc(3) and free(3).
103    */
104 #define __BIONIC_DLERROR_BUFFER_SIZE 512
105   char dlerror_buffer[__BIONIC_DLERROR_BUFFER_SIZE];
106 };
107 
108 __LIBC_HIDDEN__ int __init_thread(pthread_internal_t* thread);
109 __LIBC_HIDDEN__ void __init_tls(pthread_internal_t* thread);
110 __LIBC_HIDDEN__ void __init_alternate_signal_stack(pthread_internal_t*);
111 
112 __LIBC_HIDDEN__ pthread_t           __pthread_internal_add(pthread_internal_t* thread);
113 __LIBC_HIDDEN__ pthread_internal_t* __pthread_internal_find(pthread_t pthread_id);
114 __LIBC_HIDDEN__ void                __pthread_internal_remove(pthread_internal_t* thread);
115 __LIBC_HIDDEN__ void                __pthread_internal_remove_and_free(pthread_internal_t* thread);
116 
117 // Make __get_thread() inlined for performance reason. See http://b/19825434.
__get_thread()118 static inline __always_inline pthread_internal_t* __get_thread() {
119   return reinterpret_cast<pthread_internal_t*>(__get_tls()[TLS_SLOT_THREAD_ID]);
120 }
121 
122 __LIBC_HIDDEN__ void pthread_key_clean_all(void);
123 
124 /*
125  * Traditionally we gave threads a 1MiB stack. When we started
126  * allocating per-thread alternate signal stacks to ease debugging of
127  * stack overflows, we subtracted the same amount we were using there
128  * from the default thread stack size. This should keep memory usage
129  * roughly constant.
130  */
131 #define PTHREAD_STACK_SIZE_DEFAULT ((1 * 1024 * 1024) - SIGSTKSZ)
132 
133 /* Leave room for a guard page in the internally created signal stacks. */
134 #define SIGNAL_STACK_SIZE (SIGSTKSZ + PAGE_SIZE)
135 
136 /* Needed by fork. */
137 __LIBC_HIDDEN__ extern void __bionic_atfork_run_prepare();
138 __LIBC_HIDDEN__ extern void __bionic_atfork_run_child();
139 __LIBC_HIDDEN__ extern void __bionic_atfork_run_parent();
140 
141 #endif /* _PTHREAD_INTERNAL_H_ */
142