linux/include/linux/circ_buf.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * See Documentation/core-api/circular-buffers.rst for more information.
 */

#ifndef _LINUX_CIRC_BUF_H
#define _LINUX_CIRC_BUF_H …

struct circ_buf { … };

/* Return count in buffer.  */
#define CIRC_CNT(head,tail,size) …

/* Return space available, 0..size-1.  We always leave one free char
   as a completely full buffer has head == tail, which is the same as
   empty.  */
#define CIRC_SPACE(head,tail,size) …

/* Return count up to the end of the buffer.  Carefully avoid
   accessing head and tail more than once, so they can change
   underneath us without returning inconsistent results.  */
#define CIRC_CNT_TO_END(head,tail,size) …

/* Return space available up to the end of the buffer.  */
#define CIRC_SPACE_TO_END(head,tail,size) …

#endif /* _LINUX_CIRC_BUF_H  */