timer id and event index are independent now

[thomo]

Using the index of the event array as timer id has the disadvantage that the index may be reused/reassigned to an new timer while the original index does not realize this. (example: #5)

My solution is to use an index-independent event-id.

To make it more clear where an event-id is expected I also introduce the type event_id.

[SandyWalsh]

I assume we can close this one out now, as the other implementation was merged?

[niesteszeck]

As @thomo pointed in #5 (comment) there will be a problem when a timer ends by natural causes (time elapsed and no repeat timer) and someone try to stop it.

I have a work around in my code:

....
void resetTimeoutTimer(void* context) {
    displayTimeut = true;
    tDisplayUpdate= t.every(PERIOD_DISPLAY, displayTimeout, 0);
}
...
void setup() {
    tTimeout = t.after(SCREEN_TIMEOUT, resetTimeoutTimer, 0);
    displayTimeut = false;
}
....
void loop() {
    t.update(); // if tTimeout has ended displayTimeut will be true
    if (displayTimeut) {
            t.stop(tDisplayUpdate);
            tTimeout = t.after(SCREEN_TIMEOUT, resetTimeoutTimer, 0);
            displayTimeut = false;
    } else {
            t.stop(tTimeout);
            tTimeout = t.after(SCREEN_TIMEOUT, resetTimeoutTimer, 0);
     }
}

For my case it works fine, but I'm with @thomo that there could be a situation where someone try to stop an already stopped timer and it stop another timer

void restartT1() {
    t.stop(t1);
    t1 = t.after(1000, ledA_off);
    ledA_on();
}

void restartT2() {
    t.stop(t2);
    t2 = t.after(1000, ledB_off);
    ledB_on();
}

void stopTimer() {
    t.stop(t1);
    t.stop(t2);
}

void stopTimer1() {
    t.stop(t1);
}

void stopTimer2() {
    t.stop(t2);
}

...

void loop() {
    if eventA {
        restartT1();
    }

    if eventB {
      restartT2();
    }

    if eventC {
        stopTimer();
    }

    if eventD {
        stopTimer1();
    }

    if eventE {
        stopTimer2();
    }
}

So, what can happend:

Time | Event | t1     | t2     | desc
0    | -     | -1     | -1     | -
1    | A     | 0      | -1     | start t1 (ID=0)
...                            
10   | B     | 0      | 1      | start t2 (ID=1)
...
50   | -     | 0      | 1      | t2 ends (ID=1)
51   | -     | 0      | 1      | t1 ends (ID=0)
...                            
100  | B     | 0      | 1->0   | start t2 (ID=0)
101  | C     | 0      | 0      | stop(0) => it stops t2

I think is clear that in time 101 timer 2 (t2) get stooped by trying to stop timer 1 (t1) arising the problem mentioned by @thomo

[JChristensen]

Archiving this repo.