legacy-libs/grpc-cloned/deps/grpc/third_party/boringssl/crypto/refcount_lock.c

   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 #include "internal.h"
  16
  17 #include <stdlib.h>
  18
  19 #include <openssl/type_check.h>
  20
  21
  22 #if !defined(OPENSSL_C11_ATOMIC)
  23
  24 OPENSSL_COMPILE_ASSERT((CRYPTO_refcount_t)-1 == CRYPTO_REFCOUNT_MAX,
  25                        CRYPTO_REFCOUNT_MAX_is_incorrect);
  26
  27 static struct CRYPTO_STATIC_MUTEX g_refcount_lock = CRYPTO_STATIC_MUTEX_INIT;
  28
  29 void CRYPTO_refcount_inc(CRYPTO_refcount_t *count) {
  30   CRYPTO_STATIC_MUTEX_lock_write(&g_refcount_lock);
  31   if (*count < CRYPTO_REFCOUNT_MAX) {
  32     (*count)++;
  33   }
  34   CRYPTO_STATIC_MUTEX_unlock_write(&g_refcount_lock);
  35 }
  36
  37 int CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t *count) {
  38   int ret;
  39
  40   CRYPTO_STATIC_MUTEX_lock_write(&g_refcount_lock);
  41   if (*count == 0) {
  42     abort();
  43   }
  44   if (*count < CRYPTO_REFCOUNT_MAX) {
  45     (*count)--;
  46   }
  47   ret = (*count == 0);
  48   CRYPTO_STATIC_MUTEX_unlock_write(&g_refcount_lock);
  49
  50   return ret;
  51 }
  52
  53 #endif  // OPENSSL_C11_ATOMIC