text: /*
   *  Threading abstraction layer
   *
   *  Copyright The Mbed TLS Contributors
   *  SPDX-License-Identifier: Apache-2.0
   *
   *  Licensed under the Apache License, Version 2.0 (the "License"); you may
   *  not use this file except in compliance with the License.
   *  You may obtain a copy of the License at
   *
   *  http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   */
  
  /*
   * Ensure gmtime_r is available even with -std=c99; must be defined before
   * mbedtls_config.h, which pulls in glibc's features.h. Harmless on other platforms.
   */
  #if !defined(_POSIX_C_SOURCE)
  #define _POSIX_C_SOURCE 200112L
  #endif
  
  #include "common.h"
  
  #if defined(MBEDTLS_THREADING_C)
  
  #include "mbedtls/threading.h"
  
  #if defined(MBEDTLS_HAVE_TIME_DATE) && !defined(MBEDTLS_PLATFORM_GMTIME_R_ALT)
  
  #if !defined(_WIN32) && (defined(unix) || \
      defined(__unix) || defined(__unix__) || (defined(__APPLE__) && \
      defined(__MACH__)))
  #include <unistd.h>
  #endif /* !_WIN32 && (unix || __unix || __unix__ ||
          * (__APPLE__ && __MACH__)) */
  
  #if !( ( defined(_POSIX_VERSION) && _POSIX_VERSION >= 200809L ) ||     \
         ( defined(_POSIX_THREAD_SAFE_FUNCTIONS ) &&                     \
           _POSIX_THREAD_SAFE_FUNCTIONS >= 200112L ) )
  /*
   * This is a convenience shorthand macro to avoid checking the long
   * preprocessor conditions above. Ideally, we could expose this macro in
   * platform_util.h and simply use it in platform_util.c, threading.c and
   * threading.h. However, this macro is not part of the Mbed TLS public API, so
   * we keep it private by only defining it in this file
   */
  
  #if ! ( defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) )
  #define THREADING_USE_GMTIME
  #endif /* ! ( defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) ) */
  
  #endif /* !( ( defined(_POSIX_VERSION) && _POSIX_VERSION >= 200809L ) ||     \
               ( defined(_POSIX_THREAD_SAFE_FUNCTIONS ) &&                     \
                  _POSIX_THREAD_SAFE_FUNCTIONS >= 200112L ) ) */
  
  #endif /* MBEDTLS_HAVE_TIME_DATE && !MBEDTLS_PLATFORM_GMTIME_R_ALT */
  
  #if defined(MBEDTLS_THREADING_PTHREAD)
  static void threading_mutex_init_pthread( mbedtls_threading_mutex_t *mutex )
  {
      if( mutex == NULL )
          return;
  
      /* A nonzero value of is_valid indicates a successfully initialized
       * mutex. This is a workaround for not being able to return an error
       * code for this function. The lock/unlock functions return an error
       * if is_valid is nonzero. The Mbed TLS unit test code uses this field
       * to distinguish more states of the mutex; see
       * tests/src/threading_helpers for details. */
      mutex->is_valid = pthread_mutex_init( &mutex->mutex, NULL ) == 0;
  }
  
  static void threading_mutex_free_pthread( mbedtls_threading_mutex_t *mutex )
  {
      if( mutex == NULL || !mutex->is_valid )
          return;
  
      (void) pthread_mutex_destroy( &mutex->mutex );
      mutex->is_valid = 0;
  }
  
  static int threading_mutex_lock_pthread( mbedtls_threading_mutex_t *mutex )
  {
      if( mutex == NULL || ! mutex->is_valid )
          return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );
  
      if( pthread_mutex_lock( &mutex->mutex ) != 0 )
          return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
  
      return( 0 );
  }
  
  static int threading_mutex_unlock_pthread( mbedtls_threading_mutex_t *mutex )
  {
      if( mutex == NULL || ! mutex->is_valid )
          return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );
  
      if( pthread_mutex_unlock( &mutex->mutex ) != 0 )
          return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
  
      return( 0 );
  }
  
  void (*mbedtls_mutex_init)( mbedtls_threading_mutex_t * ) = threading_mutex_init_pthread;
  void (*mbedtls_mutex_free)( mbedtls_threading_mutex_t * ) = threading_mutex_free_pthread;
  int (*mbedtls_mutex_lock)( mbedtls_threading_mutex_t * ) = threading_mutex_lock_pthread;
  int (*mbedtls_mutex_unlock)( mbedtls_threading_mutex_t * ) = threading_mutex_unlock_pthread;
  
  /*
   * With pthreads we can statically initialize mutexes
   */
  #define MUTEX_INIT  = { PTHREAD_MUTEX_INITIALIZER, 1 }
  
  #endif /* MBEDTLS_THREADING_PTHREAD */
  
  #if defined(MBEDTLS_THREADING_ALT)
  static int threading_mutex_fail( mbedtls_threading_mutex_t *mutex )
  {
      ((void) mutex );
      return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );
  }
  static void threading_mutex_dummy( mbedtls_threading_mutex_t *mutex )
  {
      ((void) mutex );
      return;
  }
  
  void (*mbedtls_mutex_init)( mbedtls_threading_mutex_t * ) = threading_mutex_dummy;
  void (*mbedtls_mutex_free)( mbedtls_threading_mutex_t * ) = threading_mutex_dummy;
  int (*mbedtls_mutex_lock)( mbedtls_threading_mutex_t * ) = threading_mutex_fail;
  int (*mbedtls_mutex_unlock)( mbedtls_threading_mutex_t * ) = threading_mutex_fail;
  
  /*
   * Set functions pointers and initialize global mutexes
   */
  void mbedtls_threading_set_alt( void (*mutex_init)( mbedtls_threading_mutex_t * ),
                         void (*mutex_free)( mbedtls_threading_mutex_t * ),
                         int (*mutex_lock)( mbedtls_threading_mutex_t * ),
                         int (*mutex_unlock)( mbedtls_threading_mutex_t * ) )
  {
      mbedtls_mutex_init = mutex_init;
      mbedtls_mutex_free = mutex_free;
      mbedtls_mutex_lock = mutex_lock;
      mbedtls_mutex_unlock = mutex_unlock;
  
  #if defined(MBEDTLS_FS_IO)
      mbedtls_mutex_init( &mbedtls_threading_readdir_mutex );
  #endif
  #if defined(THREADING_USE_GMTIME)
      mbedtls_mutex_init( &mbedtls_threading_gmtime_mutex );
  #endif
  }
  
  /*
   * Free global mutexes
   */
  void mbedtls_threading_free_alt( void )
  {
  #if defined(MBEDTLS_FS_IO)
      mbedtls_mutex_free( &mbedtls_threading_readdir_mutex );
  #endif
  #if defined(THREADING_USE_GMTIME)
      mbedtls_mutex_free( &mbedtls_threading_gmtime_mutex );
  #endif
  }
  #endif /* MBEDTLS_THREADING_ALT */
  
  /*
   * Define global mutexes
   */
  #ifndef MUTEX_INIT
  #define MUTEX_INIT
  #endif
  #if defined(MBEDTLS_FS_IO)
  mbedtls_threading_mutex_t mbedtls_threading_readdir_mutex MUTEX_INIT;
  #endif
  #if defined(THREADING_USE_GMTIME)
  mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex MUTEX_INIT;
  #endif
  
  #endif /* MBEDTLS_THREADING_C */
  