Space pressed bug in Obj-C?

I'm working on an Obj-C app for OSX in which the user presses space (or return) to call a function. However sometimes after the user presses the space bar a couple times the program thinks the user is still pressing space, thus it calls the function thousands of times until crash. I've put a delay in so space can only be pressed once every 2 seconds, however that only slows down the crash. The only way to stop the crash is for the user to press space again.

How can I resolve this?

int key = ([[incomingEvent charactersIgnoringModifiers] UTF8String])[0];
key =开发者_开发问答 [incomingEvent keyCode];
switch(key)
{
    // return and space
    case 36:
    case 49:

        if (CFAbsoluteTimeGetCurrent() - lastSpaceTime > acceptableTimeBetweenSpace)
        {
            // do stuff
            printf("space pressed");

            // lastSpaceTime is now
            lastSpaceTime = CFAbsoluteTimeGetCurrent();
        }
        else
        {
            printf("not enough time since last space!");
            // break;
            // return incomingEvent;
        }
        break;

    case 53:

        //do stuff
        break;
}

I tried adding this:

CGEventRef simulateSpaceUp, simulateSpaceDown;

                                      simulateSpaceDown = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)49, true);
                                      simulateSpaceUp = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)49, false);

in the else block. What am I doing wrong here?

Seems like recognizing the spacebar key isnt the problem here. It does seem likely that the delay u put in is adjusted to some large amount of time (or negative).

Why arent u using a NSTimer to shutout the spacebar key method? u just set a bool prop (canNotReactToSpaceBar) to true and after timer runs out u set it back to false when the timer has run out. With the bool u just shutout the particular method when the bool is set on true, etc.