Imported Upstream version 4.8.0.309

Former-commit-id: 5f9c6ae75f295e057a7d2971f3a6df4656fa8850

external/boringssl/crypto/refcount_lock.c

@@ -0,0 +1,53 @@
+/* Copyright (c) 2015, 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 "internal.h"
+
+#include <stdlib.h>
+
+#include <openssl/type_check.h>
+
+
+#if !defined(OPENSSL_C11_ATOMIC)
+
+OPENSSL_COMPILE_ASSERT((CRYPTO_refcount_t)-1 == CRYPTO_REFCOUNT_MAX,
+                       CRYPTO_REFCOUNT_MAX_is_incorrect);
+
+static struct CRYPTO_STATIC_MUTEX g_refcount_lock = CRYPTO_STATIC_MUTEX_INIT;
+
+void CRYPTO_refcount_inc(CRYPTO_refcount_t *count) {
+  CRYPTO_STATIC_MUTEX_lock_write(&g_refcount_lock);
+  if (*count < CRYPTO_REFCOUNT_MAX) {
+    (*count)++;
+  }
+  CRYPTO_STATIC_MUTEX_unlock_write(&g_refcount_lock);
+}
+
+int CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t *count) {
+  int ret;
+
+  CRYPTO_STATIC_MUTEX_lock_write(&g_refcount_lock);
+  if (*count == 0) {
+    abort();
+  }
+  if (*count < CRYPTO_REFCOUNT_MAX) {
+    (*count)--;
+  }
+  ret = (*count == 0);
+  CRYPTO_STATIC_MUTEX_unlock_write(&g_refcount_lock);
+
+  return ret;
+}
+
+#endif  /* OPENSSL_C11_ATOMIC */