Annotation of libelwix/src/ring.c, revision 1.2
1.2 ! misho 1: /*************************************************************************
! 2: * (C) 2025 AITNET ltd - Sofia/Bulgaria - <misho@aitnet.org>
! 3: * by Michael Pounov <misho@elwix.org>
! 4: *
! 5: * $Author: misho $
! 6: * $Id: ring.c,v 1.1.2.4 2025/09/26 10:13:57 misho Exp $
! 7: *
! 8: **************************************************************************
! 9: The ELWIX and AITNET software is distributed under the following
! 10: terms:
! 11:
! 12: All of the documentation and software included in the ELWIX and AITNET
! 13: Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>
! 14:
! 15: Copyright 2004 - 2025
! 16: by Michael Pounov <misho@elwix.org>. All rights reserved.
! 17:
! 18: Redistribution and use in source and binary forms, with or without
! 19: modification, are permitted provided that the following conditions
! 20: are met:
! 21: 1. Redistributions of source code must retain the above copyright
! 22: notice, this list of conditions and the following disclaimer.
! 23: 2. Redistributions in binary form must reproduce the above copyright
! 24: notice, this list of conditions and the following disclaimer in the
! 25: documentation and/or other materials provided with the distribution.
! 26: 3. All advertising materials mentioning features or use of this software
! 27: must display the following acknowledgement:
! 28: This product includes software developed by Michael Pounov <misho@elwix.org>
! 29: ELWIX - Embedded LightWeight unIX and its contributors.
! 30: 4. Neither the name of AITNET nor the names of its contributors
! 31: may be used to endorse or promote products derived from this software
! 32: without specific prior written permission.
! 33:
! 34: THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND
! 35: ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 36: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 37: ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 38: FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 39: DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 40: OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 41: HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 42: LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 43: OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 44: SUCH DAMAGE.
! 45: */
! 46: #include "global.h"
! 47:
! 48:
! 49: /*
! 50: * rbuf_init() - Init ring buffer
! 51: *
! 52: * @rbuf = Ring buffer
! 53: * @num = Number of elements in buffer
! 54: * return: -1 error or 0 ok
! 55: */
! 56: int
! 57: rbuf_init(ringbuf_t *rbuf, int num)
! 58: {
! 59: if (!rbuf)
! 60: return -1;
! 61:
! 62: atomic_store_explicit(&rbuf->rb_head, 0, memory_order_relaxed);
! 63: atomic_store_explicit(&rbuf->rb_tail, 0, memory_order_relaxed);
! 64:
! 65: rbuf->rb_buffer = e_calloc(num, sizeof(struct iovec));
! 66: if (!rbuf->rb_buffer)
! 67: return -1;
! 68: else
! 69: rbuf->rb_bufnum = num;
! 70: memset(rbuf->rb_buffer, 0, num * sizeof(struct iovec));
! 71:
! 72: return 0;
! 73: }
! 74:
! 75: /*
! 76: * rbuf_free() - Free ring buffer
! 77: *
! 78: * @rbuf = Ring buffer
! 79: * return: none
! 80: */
! 81: void
! 82: rbuf_free(ringbuf_t *rbuf)
! 83: {
! 84: if (!rbuf)
! 85: return;
! 86:
! 87: if (rbuf->rb_buffer) {
! 88: e_free(rbuf->rb_buffer);
! 89: rbuf->rb_buffer = NULL;
! 90: rbuf->rb_bufnum = 0;
! 91: }
! 92:
! 93: atomic_store_explicit(&rbuf->rb_head, 0, memory_order_relaxed);
! 94: atomic_store_explicit(&rbuf->rb_tail, 0, memory_order_relaxed);
! 95: }
! 96:
! 97: /*
! 98: * rbuf_purge() - Purge all buffer
! 99: *
! 100: * @rbuf = Ring buffer
! 101: * return: none
! 102: */
! 103: void
! 104: rbuf_purge(ringbuf_t *rbuf)
! 105: {
! 106: if (!rbuf)
! 107: return;
! 108:
! 109: if (rbuf->rb_buffer)
! 110: memset(rbuf->rb_buffer, 0, rbuf->rb_bufnum * sizeof(struct iovec));
! 111:
! 112: atomic_store_explicit(&rbuf->rb_head, 0, memory_order_relaxed);
! 113: atomic_store_explicit(&rbuf->rb_tail, 0, memory_order_relaxed);
! 114: }
! 115:
! 116: /*
! 117: * rbuf_isempty() - Check buffer is empty
! 118: *
! 119: * @rbuf = Ring buffer
! 120: * return: -1 error, 0 it isn't empty
! 121: */
! 122: int
! 123: rbuf_isempty(ringbuf_t *rbuf)
! 124: {
! 125: if (!rbuf)
! 126: return -1;
! 127:
! 128: return (atomic_load_explicit(&rbuf->rb_head, memory_order_acquire) ==
! 129: atomic_load_explicit(&rbuf->rb_tail, memory_order_acquire));
! 130: }
! 131:
! 132: /*
! 133: * rbuf_isfull() - Check buffer is full
! 134: *
! 135: * @rbuf = Ring buffer
! 136: * return: -1 error or 0 it isn't full
! 137: */
! 138: int
! 139: rbuf_isfull(ringbuf_t *rbuf)
! 140: {
! 141: if (!rbuf)
! 142: return -1;
! 143: if (!rbuf->rb_bufnum)
! 144: return 1;
! 145:
! 146: return (((atomic_load_explicit(&rbuf->rb_head, memory_order_relaxed) + 1) % rbuf->rb_bufnum) ==
! 147: atomic_load_explicit(&rbuf->rb_tail, memory_order_acquire));
! 148: }
! 149:
! 150: /*
! 151: * rbuf_enqueue() - Enqueue data to buffer
! 152: *
! 153: * @rbuf = Ring buffer
! 154: * @data = Data
! 155: * @len = Length
! 156: * return: -1 error, 1 buffer is full or 0 ok
! 157: */
! 158: int
! 159: rbuf_enqueue(ringbuf_t *rbuf, void *data, size_t len)
! 160: {
! 161: int h, t, n;
! 162: struct iovec *iov;
! 163:
! 164: if (!rbuf || !rbuf->rb_buffer)
! 165: return -1;
! 166: if (!rbuf->rb_bufnum)
! 167: return 1;
! 168:
! 169: h = atomic_load_explicit(&rbuf->rb_head, memory_order_relaxed);
! 170: t = atomic_load_explicit(&rbuf->rb_tail, memory_order_acquire);
! 171: n = (h + 1) % rbuf->rb_bufnum;
! 172:
! 173: if (n == t)
! 174: return 1;
! 175:
! 176: iov = rbuf->rb_buffer + h;
! 177: iov->iov_len = len;
! 178: iov->iov_base = data;
! 179:
! 180: atomic_store_explicit(&rbuf->rb_head, n, memory_order_release);
! 181: return 0;
! 182: }
! 183:
! 184: /*
! 185: * rbuf_dequeue() - Dequeue data from buffer
! 186: *
! 187: * @rbuf = Ring buffer
! 188: * @out = Data, if =NULL, just dequeue data
! 189: * return: -1 error, 1 buffer is empty or 0 ok
! 190: */
! 191: int
! 192: rbuf_dequeue(ringbuf_t *rbuf, struct iovec *out)
! 193: {
! 194: int h, t, n;
! 195:
! 196: if (!rbuf || !rbuf->rb_buffer)
! 197: return -1;
! 198: if (!rbuf->rb_bufnum)
! 199: return 1;
! 200:
! 201: h = atomic_load_explicit(&rbuf->rb_head, memory_order_acquire);
! 202: t = atomic_load_explicit(&rbuf->rb_tail, memory_order_relaxed);
! 203: n = (t + 1) % rbuf->rb_bufnum;
! 204:
! 205: if (h == t)
! 206: return 1;
! 207:
! 208: if (out)
! 209: *out = rbuf->rb_buffer[t];
! 210:
! 211: atomic_store_explicit(&rbuf->rb_tail, n, memory_order_release);
! 212: return 0;
! 213: }
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