--- libelwix/src/ring.c 2025/09/26 08:58:05 1.1 +++ libelwix/src/ring.c 2025/09/26 08:58:05 1.1.2.1 @@ -0,0 +1,207 @@ +/************************************************************************* +* (C) 2025 AITNET ltd - Sofia/Bulgaria - +* by Michael Pounov +* +* $Author: misho $ +* $Id: ring.c,v 1.1.2.1 2025/09/26 08:58:05 misho Exp $ +* +************************************************************************** +The ELWIX and AITNET software is distributed under the following +terms: + +All of the documentation and software included in the ELWIX and AITNET +Releases is copyrighted by ELWIX - Sofia/Bulgaria + +Copyright 2004 - 2025 + by Michael Pounov . All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions +are met: +1. Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. +2. Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. +3. All advertising materials mentioning features or use of this software + must display the following acknowledgement: +This product includes software developed by Michael Pounov +ELWIX - Embedded LightWeight unIX and its contributors. +4. Neither the name of AITNET nor the names of its contributors + may be used to endorse or promote products derived from this software + without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND +ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +SUCH DAMAGE. +*/ +#include "global.h" + + +/* + * rbuf_init() - Init ring buffer + * + * @rbuf = Ring buffer + * @num = Number of elements in buffer + * return: -1 error or 0 ok + */ +int +rbuf_init(ringbuf_t *rbuf, int num) +{ + if (!rbuf) + return -1; + + atomic_store_explicit(&rbuf->rb_head, 0, memory_order_relaxed); + atomic_store_explicit(&rbuf->rb_tail, 0, memory_order_relaxed); + + rbuf->rb_buffer = e_calloc(num, sizeof(struct iovec)); + if (!rbuf->rb_buffer) + return -1; + else + rbuf->rb_bufnum = num; + memset(rbuf->rb_buffer, 0, num * sizeof(struct iovec)); + + return 0; +} + +/* + * rbuf_free() - Free ring buffer + * + * @rbuf = Ring buffer + * return: none + */ +void +rbuf_free(ringbuf_t *rbuf) +{ + if (!rbuf) + return; + + if (rbuf->rb_buffer) { + e_free(rbuf->rb_buffer); + rbuf->rb_buffer = NULL; + rbuf->rb_bufnum = 0; + } + + atomic_store_explicit(&rbuf->rb_head, 0, memory_order_relaxed); + atomic_store_explicit(&rbuf->rb_tail, 0, memory_order_relaxed); +} + +/* + * rbuf_purge() - Purge all buffer + * + * @rbuf = Ring buffer + * return: none + */ +void +rbuf_purge(ringbuf_t *rbuf) +{ + if (!rbuf) + return; + + if (rbuf->rb_buffer) + memset(rbuf->rb_buffer, 0, rbuf->rb_bufnum * sizeof(struct iovec)); + + atomic_store_explicit(&rbuf->rb_head, 0, memory_order_relaxed); + atomic_store_explicit(&rbuf->rb_tail, 0, memory_order_relaxed); +} + +/* + * rbuf_isempty() - Check buffer is empty + * + * @rbuf = Ring buffer + * return: -1 error, 0 it isn't empty + */ +int +rbuf_isempty(ringbuf_t *rbuf) +{ + if (!rbuf) + return -1; + + return (atomic_load_explicit(&rbuf->rb_head, memory_order_acquire) == + atomic_load_explicit(&rbuf->rb_tail, memory_order_acquire)); +} + +/* + * rbuf_isfull() - Check buffer is full + * + * @rbuf = Ring buffer + * return: -1 error or 0 it isn't full + */ +int +rbuf_isfull(ringbuf_t *rbuf) +{ + if (!rbuf) + return -1; + + return (((atomic_load_explicit(&rbuf->rb_head, memory_order_relaxed) + 1) % rbuf->rb_bufnum) == + atomic_load_explicit(&rbuf->rb_tail, memory_order_acquire)); +} + +/* + * rbuf_enqueue() - Enqueue data to buffer + * + * @rbuf = Ring buffer + * @data = Data + * @len = Length + * return: -1 error, 1 buffer is full or 0 ok + */ +int +rbuf_enqueue(ringbuf_t *rbuf, void *data, size_t len) +{ + int h, t, n; + struct iovec *iov; + + if (!rbuf) + return -1; + + h = atomic_load_explicit(&rbuf->rb_head, memory_order_relaxed); + t = atomic_load_explicit(&rbuf->rb_tail, memory_order_acquire); + n = (h + 1) % rbuf->rb_bufnum; + + if (n == t) + return 1; + + iov = rbuf->rb_buffer + h; + iov->iov_len = len; + iov->iov_base = data; + + atomic_store_explicit(&rbuf->rb_head, n, memory_order_release); + return 0; +} + +/* + * rbuf_dequeue() - Dequeue data from buffer + * + * @rbuf = Ring buffer + * @out = Data, if =NULL, just dequeue data + * return: -1 error, 1 buffer is empty or 0 ok + */ +int +rbuf_dequeue(ringbuf_t *rbuf, struct iovec *out) +{ + int h, t, n; + + if (!rbuf) + return -1; + + h = atomic_load_explicit(&rbuf->rb_head, memory_order_acquire); + t = atomic_load_explicit(&rbuf->rb_tail, memory_order_relaxed); + n = (t + 1) % rbuf->rb_bufnum; + + if (h == t) + return 1; + + if (out) + out = rbuf->rb_buffer + t; + + atomic_store_explicit(&rbuf->rb_tail, n, memory_order_release); + return 0; +}