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_lock.h"
35 #include "private/bionic_tls.h"
36 
37 /* Has the thread been detached by a pthread_join or pthread_detach call? */
38 #define PTHREAD_ATTR_FLAG_DETACHED 0x00000001
39 
40 /* Has the thread been joined by another thread? */
41 #define PTHREAD_ATTR_FLAG_JOINED 0x00000002
42 
43 class pthread_key_data_t {
44  public:
45   uintptr_t seq; // Use uintptr_t just for alignment, as we use pointer below.
46   void* data;
47 };
48 
49 enum ThreadJoinState {
50   THREAD_NOT_JOINED,
51   THREAD_EXITED_NOT_JOINED,
52   THREAD_JOINED,
53   THREAD_DETACHED
54 };
55 
56 class thread_local_dtor;
57 
58 class pthread_internal_t {
59  public:
60   class pthread_internal_t* next;
61   class pthread_internal_t* prev;
62 
63   pid_t tid;
64 
65  private:
66   pid_t cached_pid_;
67 
68  public:
invalidate_cached_pid()69   pid_t invalidate_cached_pid() {
70     pid_t old_value;
71     get_cached_pid(&old_value);
72     set_cached_pid(0);
73     return old_value;
74   }
75 
set_cached_pid(pid_t value)76   void set_cached_pid(pid_t value) {
77     cached_pid_ = value;
78   }
79 
get_cached_pid(pid_t * cached_pid)80   bool get_cached_pid(pid_t* cached_pid) {
81     *cached_pid = cached_pid_;
82     return (*cached_pid != 0);
83   }
84 
85   pthread_attr_t attr;
86 
87   _Atomic(ThreadJoinState) join_state;
88 
89   __pthread_cleanup_t* cleanup_stack;
90 
91   void* (*start_routine)(void*);
92   void* start_routine_arg;
93   void* return_value;
94 
95   void* alternate_signal_stack;
96 
97   Lock startup_handshake_lock;
98 
99   size_t mmap_size;
100 
101   thread_local_dtor* thread_local_dtors;
102 
103   void* tls[BIONIC_TLS_SLOTS];
104 
105   pthread_key_data_t key_data[BIONIC_PTHREAD_KEY_COUNT];
106 
107   /*
108    * The dynamic linker implements dlerror(3), which makes it hard for us to implement this
109    * per-thread buffer by simply using malloc(3) and free(3).
110    */
111 #define __BIONIC_DLERROR_BUFFER_SIZE 512
112   char dlerror_buffer[__BIONIC_DLERROR_BUFFER_SIZE];
113 };
114 
115 __LIBC_HIDDEN__ int __init_thread(pthread_internal_t* thread);
116 __LIBC_HIDDEN__ void __init_tls(pthread_internal_t* thread);
117 __LIBC_HIDDEN__ void __init_alternate_signal_stack(pthread_internal_t*);
118 
119 __LIBC_HIDDEN__ pthread_t           __pthread_internal_add(pthread_internal_t* thread);
120 __LIBC_HIDDEN__ pthread_internal_t* __pthread_internal_find(pthread_t pthread_id);
121 __LIBC_HIDDEN__ void                __pthread_internal_remove(pthread_internal_t* thread);
122 __LIBC_HIDDEN__ void                __pthread_internal_remove_and_free(pthread_internal_t* thread);
123 
124 // Make __get_thread() inlined for performance reason. See http://b/19825434.
__get_thread()125 static inline __always_inline pthread_internal_t* __get_thread() {
126   return reinterpret_cast<pthread_internal_t*>(__get_tls()[TLS_SLOT_THREAD_ID]);
127 }
128 
129 __LIBC_HIDDEN__ void pthread_key_clean_all(void);
130 
131 /*
132  * Traditionally we gave threads a 1MiB stack. When we started
133  * allocating per-thread alternate signal stacks to ease debugging of
134  * stack overflows, we subtracted the same amount we were using there
135  * from the default thread stack size. This should keep memory usage
136  * roughly constant.
137  */
138 #define PTHREAD_STACK_SIZE_DEFAULT ((1 * 1024 * 1024) - SIGSTKSZ)
139 
140 // Leave room for a guard page in the internally created signal stacks.
141 #if defined(__LP64__)
142 // SIGSTKSZ is not big enough for 64-bit arch. See http://b/23041777.
143 #define SIGNAL_STACK_SIZE (16 * 1024 + PAGE_SIZE)
144 #else
145 #define SIGNAL_STACK_SIZE (SIGSTKSZ + PAGE_SIZE)
146 #endif
147 
148 /* Needed by fork. */
149 __LIBC_HIDDEN__ extern void __bionic_atfork_run_prepare();
150 __LIBC_HIDDEN__ extern void __bionic_atfork_run_child();
151 __LIBC_HIDDEN__ extern void __bionic_atfork_run_parent();
152 
153 #endif /* _PTHREAD_INTERNAL_H_ */
154