1 /**
2  * \file threading.h
3  *
4  * \brief Threading abstraction layer
5  */
6 /*
7  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
8  *  SPDX-License-Identifier: Apache-2.0
9  *
10  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
11  *  not use this file except in compliance with the License.
12  *  You may obtain a copy of the License at
13  *
14  *  http://www.apache.org/licenses/LICENSE-2.0
15  *
16  *  Unless required by applicable law or agreed to in writing, software
17  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
18  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19  *  See the License for the specific language governing permissions and
20  *  limitations under the License.
21  *
22  *  This file is part of mbed TLS (https://tls.mbed.org)
23  */
24 #ifndef MBEDTLS_THREADING_H
25 #define MBEDTLS_THREADING_H
26 
27 #if !defined(MBEDTLS_CONFIG_FILE)
28 #include "config.h"
29 #else
30 #include MBEDTLS_CONFIG_FILE
31 #endif
32 
33 #include <stdlib.h>
34 
35 #ifdef __cplusplus
36 extern "C" {
37 #endif
38 
39 /* MBEDTLS_ERR_THREADING_FEATURE_UNAVAILABLE is deprecated and should not be
40  * used. */
41 #define MBEDTLS_ERR_THREADING_FEATURE_UNAVAILABLE         -0x001A  /**< The selected feature is not available. */
42 
43 #define MBEDTLS_ERR_THREADING_BAD_INPUT_DATA              -0x001C  /**< Bad input parameters to function. */
44 #define MBEDTLS_ERR_THREADING_MUTEX_ERROR                 -0x001E  /**< Locking / unlocking / free failed with error code. */
45 
46 #if defined(MBEDTLS_THREADING_PTHREAD)
47 #include <pthread.h>
48 typedef struct mbedtls_threading_mutex_t
49 {
50     pthread_mutex_t mutex;
51     char is_valid;
52 } mbedtls_threading_mutex_t;
53 #endif
54 
55 #if defined(MBEDTLS_THREADING_ALT)
56 /* You should define the mbedtls_threading_mutex_t type in your header */
57 #include "threading_alt.h"
58 
59 /**
60  * \brief           Set your alternate threading implementation function
61  *                  pointers and initialize global mutexes. If used, this
62  *                  function must be called once in the main thread before any
63  *                  other mbed TLS function is called, and
64  *                  mbedtls_threading_free_alt() must be called once in the main
65  *                  thread after all other mbed TLS functions.
66  *
67  * \note            mutex_init() and mutex_free() don't return a status code.
68  *                  If mutex_init() fails, it should leave its argument (the
69  *                  mutex) in a state such that mutex_lock() will fail when
70  *                  called with this argument.
71  *
72  * \param mutex_init    the init function implementation
73  * \param mutex_free    the free function implementation
74  * \param mutex_lock    the lock function implementation
75  * \param mutex_unlock  the unlock function implementation
76  */
77 void mbedtls_threading_set_alt( void (*mutex_init)( mbedtls_threading_mutex_t * ),
78                        void (*mutex_free)( mbedtls_threading_mutex_t * ),
79                        int (*mutex_lock)( mbedtls_threading_mutex_t * ),
80                        int (*mutex_unlock)( mbedtls_threading_mutex_t * ) );
81 
82 /**
83  * \brief               Free global mutexes.
84  */
85 void mbedtls_threading_free_alt( void );
86 #endif /* MBEDTLS_THREADING_ALT */
87 
88 #if defined(MBEDTLS_THREADING_C)
89 /*
90  * The function pointers for mutex_init, mutex_free, mutex_ and mutex_unlock
91  *
92  * All these functions are expected to work or the result will be undefined.
93  */
94 extern void (*mbedtls_mutex_init)( mbedtls_threading_mutex_t *mutex );
95 extern void (*mbedtls_mutex_free)( mbedtls_threading_mutex_t *mutex );
96 extern int (*mbedtls_mutex_lock)( mbedtls_threading_mutex_t *mutex );
97 extern int (*mbedtls_mutex_unlock)( mbedtls_threading_mutex_t *mutex );
98 
99 /*
100  * Global mutexes
101  */
102 #if defined(MBEDTLS_FS_IO)
103 extern mbedtls_threading_mutex_t mbedtls_threading_readdir_mutex;
104 #endif
105 
106 #if defined(MBEDTLS_HAVE_TIME_DATE) && !defined(MBEDTLS_PLATFORM_GMTIME_R_ALT)
107 /* This mutex may or may not be used in the default definition of
108  * mbedtls_platform_gmtime_r(), but in order to determine that,
109  * we need to check POSIX features, hence modify _POSIX_C_SOURCE.
110  * With the current approach, this declaration is orphaned, lacking
111  * an accompanying definition, in case mbedtls_platform_gmtime_r()
112  * doesn't need it, but that's not a problem. */
113 extern mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex;
114 #endif /* MBEDTLS_HAVE_TIME_DATE && !MBEDTLS_PLATFORM_GMTIME_R_ALT */
115 
116 #endif /* MBEDTLS_THREADING_C */
117 
118 #ifdef __cplusplus
119 }
120 #endif
121 
122 #endif /* threading.h */
123