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#ifndef AWS_COMMON_RING_BUFFER_INL
#define AWS_COMMON_RING_BUFFER_INL
/**
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
* SPDX-License-Identifier: Apache-2.0.
*/
#include <aws/common/ring_buffer.h>
AWS_EXTERN_C_BEGIN
/*
* Checks whether atomic_ptr correctly points to a memory location within the bounds of the aws_ring_buffer
*/
AWS_STATIC_IMPL bool aws_ring_buffer_check_atomic_ptr(
const struct aws_ring_buffer *ring_buf,
const uint8_t *atomic_ptr) {
return ((atomic_ptr != NULL) && (atomic_ptr >= ring_buf->allocation && atomic_ptr <= ring_buf->allocation_end));
}
/**
* Checks whether the ring buffer is empty
*/
AWS_STATIC_IMPL bool aws_ring_buffer_is_empty(const struct aws_ring_buffer *ring_buf) {
uint8_t *head = (uint8_t *)aws_atomic_load_ptr(&ring_buf->head);
uint8_t *tail = (uint8_t *)aws_atomic_load_ptr(&ring_buf->tail);
return head == tail;
}
/**
* Evaluates the set of properties that define the shape of all valid aws_ring_buffer structures.
* It is also a cheap check, in the sense it run in constant time (i.e., no loops or recursion).
*/
AWS_STATIC_IMPL bool aws_ring_buffer_is_valid(const struct aws_ring_buffer *ring_buf) {
uint8_t *head = (uint8_t *)aws_atomic_load_ptr(&ring_buf->head);
uint8_t *tail = (uint8_t *)aws_atomic_load_ptr(&ring_buf->tail);
bool head_in_range = aws_ring_buffer_check_atomic_ptr(ring_buf, head);
bool tail_in_range = aws_ring_buffer_check_atomic_ptr(ring_buf, tail);
/* if head points-to the first element of the buffer then tail must too */
bool valid_head_tail = (head != ring_buf->allocation) || (tail == ring_buf->allocation);
return ring_buf && (ring_buf->allocation != NULL) && head_in_range && tail_in_range && valid_head_tail &&
(ring_buf->allocator != NULL);
}
AWS_EXTERN_C_END
#endif /* AWS_COMMON_RING_BUFFER_INL */
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