Problems with Event Queue

[Andrew Myers]

In article <14653 at thorin.cs.unc.edu> surles at robinett.cs.unc.edu (Mark Surles) writes:
>Is there any way to get both the event type and the value
>without dequeueing the event?  Or, can I read the event and then
>somehow put it back at the FRONT of the queue?
>Mark Surles
>surles at cs.unc.edu

You could implement a wrapper around qtest/qread, whose implementation
would depend on how deep a pushback you needed. If you only need one
level, something like this should suffice:

#include "gl.h"
#include "assert.h"

long q_dev;
short q_data;
int q_hasdata;

long my_qtest()
{
    if (q_hasdata) return q_dev;
    else return qtest();
}

long my_qread(short *data)
{
    if (q_hasdata) {
	*data = q_data;
	return q_dev;
    } else {
	return qread(data);
    }
}

void my_qunread(long dev, short data)
{
    assert(!q_hasdata); /* one level pushback requirement */
    assert(dev != 0);   /* dev==0 wouldn't make sense */
    q_dev = dev;
    q_data = data;
}


-----
Andrew