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 1.4 2025/09/30 11:38:28 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((atomic_int*) &rbuf->rb_head, 0, memory_order_relaxed);
63: atomic_store_explicit((atomic_int*) &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((atomic_int*) &rbuf->rb_head, 0, memory_order_relaxed);
94: atomic_store_explicit((atomic_int*) &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((atomic_int*) &rbuf->rb_head, 0, memory_order_relaxed);
113: atomic_store_explicit((atomic_int*) &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((atomic_int*) &rbuf->rb_head, memory_order_acquire) ==
129: atomic_load_explicit((atomic_int*) &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((atomic_int*) &rbuf->rb_head, memory_order_relaxed) + 1) % rbuf->rb_bufnum) ==
147: atomic_load_explicit((atomic_int*) &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((atomic_int*) &rbuf->rb_head, memory_order_relaxed);
170: t = atomic_load_explicit((atomic_int*) &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((atomic_int*) &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((atomic_int*) &rbuf->rb_head, memory_order_acquire);
202: t = atomic_load_explicit((atomic_int*) &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((atomic_int*) &rbuf->rb_tail, n, memory_order_release);
212: return 0;
213: }
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