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#include <EXTERN.h>
#include <perl.h>
#include <glib.h>
#include "libvxi11client.h"
#define DEBUG
#ifdef DEBUG
#include <stdio.h>
#endif
// thread safe queue for stacking up interrupts
static GAsyncQueue* interruptqueue;
typedef struct {
gchar* handle;
} Event;
static Event* lastevent = NULL;
// perl is responsible for freeing the handle
static void freeevent(Event* event) {
g_free(event);
}
static void freelast() {
if (lastevent != NULL ) {
freeevent(lastevent);
lastevent = NULL;
}
}
/**
* This is the callback that is passed to the interrupt
* thread for it to run each time it gets an interrupt.
* It creates a new event, puts the handle in place and
* puts in the in the queue for someone to collect later
*/
static void interruptcallback(gchar* handle) {
Event* event = g_malloc(sizeof(Event));
event->handle = handle;
g_async_queue_push(interruptqueue, event);
}
/**
* This is just for perl, it creates a new "context" and passes
* that to the real open function
*/
VXI11Context* glue_open(char* address, char* device) {
VXI11Context* context = malloc(sizeof(VXI11Context));
if (context == NULL )
return NULL ;
int err = vxi11_open(context, address, device);
return context;
}
/**
* Create a queue, start the interrupt server, and give it our callback
*/
int glue_start_interrupt_server() {
interruptqueue = g_async_queue_new();
g_async_queue_ref(interruptqueue);
return vxi11_start_interrupt_server(interruptcallback);
}
/**
* Close down the interrupt server and free everything
*/
int glue_stop_interrupt_server() {
int ret = vxi11_stop_interrupt_server();
Event* event = NULL;
// clear everything that is left over
while ((event = (Event*) g_async_queue_try_pop(interruptqueue)) != NULL ) {
freeevent(event);
}
freelast();
g_async_queue_unref(interruptqueue);
interruptqueue = NULL;
return ret;
}
/**
* Block until an interrupt happens. A time out of -1 while block until an
* interrupt happens or forever(!), 0 will not block and only return a handle
* if an interrupt already happened, any value > 0 will return instantly if there
* is a queued interrupt or wait for one to happen up to the timeout.
*/
char* glue_wait_for_interrupt(int timeout) {
if (interruptqueue == NULL ) {
#ifdef DEBUG
printf("interrupt queue is null!\n");
#endif
return NULL ;
}
// if timeout > 0 pop with a time out,
// if the timeout is 0 try to pop but don't block
// if the timeout is -1 block until an interrupt happens
freelast();
if (timeout > 0) {
GTimeVal whentotimeout;
g_get_current_time(&whentotimeout);
g_time_val_add(&whentotimeout, timeout * 1000);
lastevent = (Event*) g_async_queue_timed_pop(interruptqueue, &whentotimeout);
}
else if (timeout == 0) {
lastevent = (Event*) g_async_queue_try_pop(interruptqueue);
}
else if (timeout == -1) {
lastevent = (Event*) g_async_queue_pop(interruptqueue);
}
if (lastevent != NULL ) {
return lastevent->handle;
}
else
return NULL ;
}
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