xref: /aosp_15_r20/external/boringssl/src/crypto/thread_pthread.c (revision 8fb009dc861624b67b6cdb62ea21f0f22d0c584b)
1 /* Copyright (c) 2015, Google Inc.
2  *
3  * Permission to use, copy, modify, and/or distribute this software for any
4  * purpose with or without fee is hereby granted, provided that the above
5  * copyright notice and this permission notice appear in all copies.
6  *
7  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14 
15 // Ensure we can't call OPENSSL_malloc circularly.
16 #define _BORINGSSL_PROHIBIT_OPENSSL_MALLOC
17 #include "internal.h"
18 
19 #if defined(OPENSSL_PTHREADS)
20 
21 #include <assert.h>
22 #include <pthread.h>
23 #include <stdlib.h>
24 #include <string.h>
25 
CRYPTO_MUTEX_init(CRYPTO_MUTEX * lock)26 void CRYPTO_MUTEX_init(CRYPTO_MUTEX *lock) {
27   if (pthread_rwlock_init(lock, NULL) != 0) {
28     abort();
29   }
30 }
31 
CRYPTO_MUTEX_lock_read(CRYPTO_MUTEX * lock)32 void CRYPTO_MUTEX_lock_read(CRYPTO_MUTEX *lock) {
33   if (pthread_rwlock_rdlock(lock) != 0) {
34     abort();
35   }
36 }
37 
CRYPTO_MUTEX_lock_write(CRYPTO_MUTEX * lock)38 void CRYPTO_MUTEX_lock_write(CRYPTO_MUTEX *lock) {
39   if (pthread_rwlock_wrlock(lock) != 0) {
40     abort();
41   }
42 }
43 
CRYPTO_MUTEX_unlock_read(CRYPTO_MUTEX * lock)44 void CRYPTO_MUTEX_unlock_read(CRYPTO_MUTEX *lock) {
45   if (pthread_rwlock_unlock(lock) != 0) {
46     abort();
47   }
48 }
49 
CRYPTO_MUTEX_unlock_write(CRYPTO_MUTEX * lock)50 void CRYPTO_MUTEX_unlock_write(CRYPTO_MUTEX *lock) {
51   if (pthread_rwlock_unlock(lock) != 0) {
52     abort();
53   }
54 }
55 
CRYPTO_MUTEX_cleanup(CRYPTO_MUTEX * lock)56 void CRYPTO_MUTEX_cleanup(CRYPTO_MUTEX *lock) {
57   pthread_rwlock_destroy(lock);
58 }
59 
CRYPTO_once(CRYPTO_once_t * once,void (* init)(void))60 void CRYPTO_once(CRYPTO_once_t *once, void (*init)(void)) {
61   if (pthread_once(once, init) != 0) {
62     abort();
63   }
64 }
65 
66 static pthread_mutex_t g_destructors_lock = PTHREAD_MUTEX_INITIALIZER;
67 static thread_local_destructor_t g_destructors[NUM_OPENSSL_THREAD_LOCALS];
68 
69 // thread_local_destructor is called when a thread exits. It releases thread
70 // local data for that thread only.
thread_local_destructor(void * arg)71 static void thread_local_destructor(void *arg) {
72   if (arg == NULL) {
73     return;
74   }
75 
76   thread_local_destructor_t destructors[NUM_OPENSSL_THREAD_LOCALS];
77   if (pthread_mutex_lock(&g_destructors_lock) != 0) {
78     return;
79   }
80   OPENSSL_memcpy(destructors, g_destructors, sizeof(destructors));
81   pthread_mutex_unlock(&g_destructors_lock);
82 
83   unsigned i;
84   void **pointers = arg;
85   for (i = 0; i < NUM_OPENSSL_THREAD_LOCALS; i++) {
86     if (destructors[i] != NULL) {
87       destructors[i](pointers[i]);
88     }
89   }
90 
91   free(pointers);
92 }
93 
94 static pthread_once_t g_thread_local_init_once = PTHREAD_ONCE_INIT;
95 static pthread_key_t g_thread_local_key;
96 static int g_thread_local_key_created = 0;
97 
thread_local_init(void)98 static void thread_local_init(void) {
99   g_thread_local_key_created =
100       pthread_key_create(&g_thread_local_key, thread_local_destructor) == 0;
101 }
102 
CRYPTO_get_thread_local(thread_local_data_t index)103 void *CRYPTO_get_thread_local(thread_local_data_t index) {
104   CRYPTO_once(&g_thread_local_init_once, thread_local_init);
105   if (!g_thread_local_key_created) {
106     return NULL;
107   }
108 
109   void **pointers = pthread_getspecific(g_thread_local_key);
110   if (pointers == NULL) {
111     return NULL;
112   }
113   return pointers[index];
114 }
115 
CRYPTO_set_thread_local(thread_local_data_t index,void * value,thread_local_destructor_t destructor)116 int CRYPTO_set_thread_local(thread_local_data_t index, void *value,
117                             thread_local_destructor_t destructor) {
118   CRYPTO_once(&g_thread_local_init_once, thread_local_init);
119   if (!g_thread_local_key_created) {
120     destructor(value);
121     return 0;
122   }
123 
124   void **pointers = pthread_getspecific(g_thread_local_key);
125   if (pointers == NULL) {
126     pointers = malloc(sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
127     if (pointers == NULL) {
128       destructor(value);
129       return 0;
130     }
131     OPENSSL_memset(pointers, 0, sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
132     if (pthread_setspecific(g_thread_local_key, pointers) != 0) {
133       free(pointers);
134       destructor(value);
135       return 0;
136     }
137   }
138 
139   if (pthread_mutex_lock(&g_destructors_lock) != 0) {
140     destructor(value);
141     return 0;
142   }
143   g_destructors[index] = destructor;
144   pthread_mutex_unlock(&g_destructors_lock);
145 
146   pointers[index] = value;
147   return 1;
148 }
149 
150 #endif  // OPENSSL_PTHREADS
151