Line data    Source code

       1             : #ifndef AWS_COMMON_RING_BUFFER_INL
       2             : #define AWS_COMMON_RING_BUFFER_INL
       3             : /**
       4             :  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
       5             :  * SPDX-License-Identifier: Apache-2.0.
       6             :  */
       7             : 
       8             : #include <aws/common/ring_buffer.h>
       9             : 
      10             : AWS_EXTERN_C_BEGIN
      11             : /*
      12             :  * Checks whether atomic_ptr correctly points to a memory location within the bounds of the aws_ring_buffer
      13             :  */
      14             : AWS_STATIC_IMPL bool aws_ring_buffer_check_atomic_ptr(
      15             :     const struct aws_ring_buffer *ring_buf,
      16       80838 :     const uint8_t *atomic_ptr) {
      17       80838 :     return (atomic_ptr >= ring_buf->allocation && atomic_ptr <= ring_buf->allocation_end);
      18       80838 : }
      19             : 
      20             : /**
      21             :  * Checks whether the ring buffer is empty
      22             :  */
      23           0 : AWS_STATIC_IMPL bool aws_ring_buffer_is_empty(const struct aws_ring_buffer *ring_buf) {
      24           0 :     uint8_t *head = (uint8_t *)aws_atomic_load_ptr(&ring_buf->head);
      25           0 :     uint8_t *tail = (uint8_t *)aws_atomic_load_ptr(&ring_buf->tail);
      26           0 :     return head == tail;
      27           0 : }
      28             : 
      29             : /**
      30             :  * Evaluates the set of properties that define the shape of all valid aws_ring_buffer structures.
      31             :  * It is also a cheap check, in the sense it run in constant time (i.e., no loops or recursion).
      32             :  */
      33       40419 : AWS_STATIC_IMPL bool aws_ring_buffer_is_valid(const struct aws_ring_buffer *ring_buf) {
      34       40419 :     uint8_t *head = (uint8_t *)aws_atomic_load_ptr(&ring_buf->head);
      35       40419 :     uint8_t *tail = (uint8_t *)aws_atomic_load_ptr(&ring_buf->tail);
      36       40419 :     bool head_in_range = aws_ring_buffer_check_atomic_ptr(ring_buf, head);
      37       40419 :     bool tail_in_range = aws_ring_buffer_check_atomic_ptr(ring_buf, tail);
      38       40419 :     /* if head points-to the first element of the buffer then tail must too */
      39       40419 :     bool valid_head_tail = (head != ring_buf->allocation) || (tail == ring_buf->allocation);
      40       40419 :     return ring_buf && AWS_MEM_IS_READABLE(ring_buf->allocation, ring_buf->allocation_end - ring_buf->allocation) &&
      41       40419 :            head_in_range && tail_in_range && valid_head_tail && (ring_buf->allocator != NULL);
      42       40419 : }
      43             : AWS_EXTERN_C_END
      44             : #endif /* AWS_COMMON_RING_BUFFER_INL */