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#include <stdio.h>
#include "erl_driver.h"
#include <errno.h>
/* -------------------------------------------------------------------------
** Data types
**/
enum e_heavy {
heavy_off, heavy_set, heavy_reset
};
typedef struct _erl_drv_data {
ErlDrvPort erlang_port;
enum e_heavy heavy;
int crash;
} EchoDrvData;
static EchoDrvData echo_drv_data, *echo_drv_data_p;
/* -------------------------------------------------------------------------
** Entry struct
**/
static EchoDrvData *echo_drv_start(ErlDrvPort port, char *command);
static void echo_drv_stop(ErlDrvData drv_data);
static void echo_drv_output(ErlDrvData drv_data, char *buf,
ErlDrvSizeT len);
static void echo_drv_finish(void);
static ErlDrvSSizeT echo_drv_control(ErlDrvData drv_data,
unsigned int command,
char *buf, ErlDrvSizeT len,
char **rbuf, ErlDrvSizeT rlen);
static ErlDrvEntry echo_drv_entry = {
NULL, /* init */
echo_drv_start,
echo_drv_stop,
echo_drv_output,
NULL, /* ready_input */
NULL, /* ready_output */
"echo_drv",
echo_drv_finish,
NULL, /* handle */
echo_drv_control,
NULL, /* timeout */
NULL, /* outputv */
NULL, /* ready_async */
NULL,
NULL,
NULL,
ERL_DRV_EXTENDED_MARKER,
ERL_DRV_EXTENDED_MAJOR_VERSION,
ERL_DRV_EXTENDED_MINOR_VERSION,
0,
NULL,
NULL,
NULL
};
/* -------------------------------------------------------------------------
** Entry functions
**/
DRIVER_INIT(echo_drv)
{
echo_drv_data_p = NULL;
return &echo_drv_entry;
}
static EchoDrvData *echo_drv_start(ErlDrvPort port, char *command)
{
if (echo_drv_data_p != NULL) {
return ERL_DRV_ERROR_GENERAL;
}
echo_drv_data_p = &echo_drv_data;
echo_drv_data_p->erlang_port = port;
echo_drv_data_p->heavy = heavy_off;
echo_drv_data_p->crash = 0;
return echo_drv_data_p;
}
static void echo_drv_stop(EchoDrvData *data_p) {
echo_drv_data_p = NULL;
}
static void echo_drv_output(ErlDrvData drv_data, char *buf, ErlDrvSizeT len) {
EchoDrvData* data_p = (EchoDrvData *) drv_data;
if (data_p->crash) {
driver_failure_posix(data_p->erlang_port, EINTR);
return;
}
driver_output(data_p->erlang_port, buf, len);
switch (data_p->heavy) {
case heavy_off:
break;
case heavy_set:
set_port_control_flags(data_p->erlang_port, PORT_CONTROL_FLAG_HEAVY);
data_p->heavy = heavy_reset;
break;
case heavy_reset:
set_port_control_flags(data_p->erlang_port, 0);
data_p->heavy = heavy_off;
break;
}
}
static void echo_drv_finish() {
echo_drv_data_p = NULL;
}
static ErlDrvSSizeT echo_drv_control(ErlDrvData drv_data,
unsigned int command,
char *buf, ErlDrvSizeT len,
char **rbuf, ErlDrvSizeT rlen) {
EchoDrvData* data_p = (EchoDrvData *) drv_data;
switch (command) {
case 'h':
data_p->heavy = heavy_set;
break;
case 'c':
data_p->crash = 1;
}
return 0;
}
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