1 /**
2  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
3  * SPDX-License-Identifier: Apache-2.0.
4  */
5 #include <aws/common/ref_count.h>
6 
7 #include <aws/common/clock.h>
8 #include <aws/common/condition_variable.h>
9 #include <aws/common/mutex.h>
10 
aws_ref_count_init(struct aws_ref_count * ref_count,void * object,aws_simple_completion_callback * on_zero_fn)11 void aws_ref_count_init(struct aws_ref_count *ref_count, void *object, aws_simple_completion_callback *on_zero_fn) {
12     aws_atomic_init_int(&ref_count->ref_count, 1);
13     ref_count->object = object;
14     ref_count->on_zero_fn = on_zero_fn;
15 }
16 
aws_ref_count_acquire(struct aws_ref_count * ref_count)17 void *aws_ref_count_acquire(struct aws_ref_count *ref_count) {
18     aws_atomic_fetch_add(&ref_count->ref_count, 1);
19 
20     return ref_count->object;
21 }
22 
aws_ref_count_release(struct aws_ref_count * ref_count)23 size_t aws_ref_count_release(struct aws_ref_count *ref_count) {
24     size_t old_value = aws_atomic_fetch_sub(&ref_count->ref_count, 1);
25     AWS_ASSERT(old_value > 0 && "refcount has gone negative");
26     if (old_value == 1) {
27         ref_count->on_zero_fn(ref_count->object);
28     }
29 
30     return old_value - 1;
31 }
32