text: /* Copyright (c) 2017, Google Inc.
   *
   * Permission to use, copy, modify, and/or distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
   * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
   * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
   * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
  
  #include <openssl/rand.h>
  
  #include <stdlib.h>
  
  #include "../fipsmodule/rand/internal.h"
  
  
  // g_buffering_enabled is true if fork-unsafe buffering has been enabled.
  static int g_buffering_enabled = 0;
  
  // g_lock protects |g_buffering_enabled|.
  static struct CRYPTO_STATIC_MUTEX g_lock = CRYPTO_STATIC_MUTEX_INIT;
  
  #if !defined(OPENSSL_WINDOWS)
  void RAND_enable_fork_unsafe_buffering(int fd) {
    // We no longer support setting the file-descriptor with this function.
    if (fd != -1) {
      abort();
    }
  
    CRYPTO_STATIC_MUTEX_lock_write(&g_lock);
    g_buffering_enabled = 1;
    CRYPTO_STATIC_MUTEX_unlock_write(&g_lock);
  }
  #endif
  
  int rand_fork_unsafe_buffering_enabled(void) {
    CRYPTO_STATIC_MUTEX_lock_read(&g_lock);
    const int ret = g_buffering_enabled;
    CRYPTO_STATIC_MUTEX_unlock_read(&g_lock);
    return ret;
  }
  