3 fast inter-user-process single-reader/single-writer channels
\r
4 using a modified version of jack ringbuffers and memory-mapped files.
\r
6 This file is part of a program that implements a Software-Defined Radio.
\r
8 Copyright (C) 2004 by Frank Brickle, AB2KT and Bob McGwier, N4HY
\r
10 This program is free software; you can redistribute it and/or modify
\r
11 it under the terms of the GNU General Public License as published by
\r
12 the Free Software Foundation; either version 2 of the License, or
\r
13 (at your option) any later version.
\r
15 This program is distributed in the hope that it will be useful,
\r
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
\r
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
\r
18 GNU General Public License for more details.
\r
20 You should have received a copy of the GNU General Public License
\r
21 along with this program; if not, write to the Free Software
\r
22 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
\r
24 The authors can be reached by email at
\r
28 rwmcgwier@comcast.net
\r
32 The DTTS Microwave Society
\r
34 Bridgewater, NJ 08807
\r
39 //------------------------------------------------------------------------
\r
42 putChan(Chan c, char *data, size_t size) {
\r
43 return ringb_write(c->rb, data, size);
\r
47 getChan(Chan c, char *data, size_t size) {
\r
48 return ringb_read(c->rb, data, size);
\r
52 putChan_nowait(Chan c, char *data, size_t size) {
\r
53 if (ringb_write_space(c->rb) >= size) {
\r
54 ringb_write(c->rb, data, size);
\r
56 } else return FALSE;
\r
60 getChan_nowait(Chan c, char *data, size_t size) {
\r
61 if (ringb_read_space(c->rb) >= size) {
\r
62 ringb_read(c->rb, data, size);
\r
64 } else return FALSE;
\r
68 openChan(char *path,size_t want) {
\r
69 Chan c = (Chan) safealloc(sizeof(ChanDesc), 1, "Chan header");
\r
70 c->size.rib = sizeof(ringb_t);
\r
71 c->size.buf = (size_t) nblock2((int) want);
\r
73 c->file.path = path;
\r
74 if ((c->file.desc = open(c->file.path, O_RDWR)) == -1) {
\r
75 fprintf(stderr, "can't open Chan file %s\n", c->file.path);
\r
78 c->size.tot = c->size.rib + c->size.buf;
\r
79 if ((c->size.tru = fdsize(c->file.desc)) < c->size.tot) {
\r
81 "Chan file %s is too small (%d) for required size (%s)\n",
\r
82 c->file.path, c->size.tru, c->size.tot);
\r
85 if (!(c->map.base = (char *) mmap(0,
\r
87 PROT_READ | PROT_WRITE,
\r
91 fprintf(stderr, "can't memory map %s for Chan\n",
\r
96 if (!(c->rb = ringb_create(c->size.buf))) {
\r
97 fprintf(stderr, "can't make RB for Chan\n");
\r
104 closeChan(Chan c) {
\r
107 munmap(c->map.base, c->size.tot);
\r
108 close(c->file.desc);
\r
110 ringb_destroy(c->rb);
\r
111 safefree((char *) c);
\r