1 /****************************************************************************
2     Copyright (C) 1987-2015 by Jeffery P. Hansen
3 
4     This program is free software; you can redistribute it and/or modify
5     it under the terms of the GNU General Public License as published by
6     the Free Software Foundation; either version 2 of the License, or
7     (at your option) any later version.
8 
9     This program is distributed in the hope that it will be useful,
10     but WITHOUT ANY WARRANTY; without even the implied warranty of
11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12     GNU General Public License for more details.
13 
14     You should have received a copy of the GNU General Public License along
15     with this program; if not, write to the Free Software Foundation, Inc.,
16     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 ****************************************************************************/
18 #ifndef __channel_h
19 #define __channel_h
20 /*****************************************************************************
21  *
22  * Data Channel Data Structures
23  *
24  * Data queues are used to implement communication channels.  These are accessed
25  * through the system tasks $tkg$write and $tkg$read.  It is also possible for
26  * the GUI write to a channel through command $write.
27  *
28  *****************************************************************************/
29 
30 struct Channel_str {
31   char			*c_name;	/* Name of channel */
32   List/*Value*/		c_queue;	/* Queue of channel */
33   List/*Event*/		c_wake;		/* Events to be executed on wake up */
34   int			c_isWatched;	/* Flag to indicated if this is a "watched" channel */
35   char			*c_format;	/* Format for watched data */
36 };
37 
38 Channel *new_Channel(const char *name);
39 int Channel_queueLen(Channel *c);
40 void Channel_wait(Channel *c, VGThread *thread);
41 int Channel_read(Channel *c, Value *data);
42 int Channel_write(Channel *c, Value *data);
43 int Channel_setWatch(Channel *c, int doWatch, const char *format);
44 
45 #endif
46