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/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 1996-2016. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* %CopyrightEnd%
*/
/* Purpose: Multidriver interface
This is an example of a driver which allows multiple instances of itself.
I.e have one erlang process execute open_port(multi......) and
at the same time have another erlang process open another port
running multi there as well.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "erl_driver.h"
#include "sys.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define MAXCHANNEL 20
static char buf[BUFSIZ];
static ErlDrvData multi_start(ErlDrvPort, char*);
static int multi_init(void);
static void multi_stop(ErlDrvData),multi_erlang_read(ErlDrvData, char*, int);
struct driver_entry multi_driver_entry = {
multi_init,
multi_start,
multi_stop,
multi_erlang_read,
NULL,
NULL,
"multi"
};
struct channel {
ErlDrvPort portno;
int channel;
};
struct channel channels[MAXCHANNEL]; /* Max MAXCHANNEL instances */
static int multi_init(void)
{
memzero(channels,MAXCHANNEL * sizeof(struct channel));
return 0;
}
static ErlDrvData multi_start(ErlDrvPort port, char* buf)
{
int chan;
chan = get_new_channel();
channels[port].portno = port;
channels[port].channel = chan;
fprintf(stderr,"Opening channel %d port is %d\n",chan,port);
return (ErlDrvData)port;
}
static int multi_stop(ErlDrvData port)
{
fprintf(stderr,"Closing channel %d\n",channels[port].channel);
remove_channel(channels[(int)port].channel);
}
static int multi_erlang_read(ErlDrvData port, char* buf, int count)
{
fprintf(stderr,"Writing %d bytes to channel %d\n",
count,
channels[(int)port].channel);
}
/* These two funs are fake */
int get_new_channel()
{
static int ch = 1;
return(ch++);
}
void remove_channel(int ch)
{
}
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