Weird result testing operation per sec

I'm running on node 8.11 this test script:

let end = false;



let i = 0;

setInterval(() => { i++; }).unref();





let k = 0;

async function loop() {

  k++

  if (end === false)

    setImmediate(loop);

}



console.time('test');

loop()

  .then(() => {

    setTimeout(() => {

      end = true;

      console.log('interval', i);

      console.log('recursion', k);

      console.timeEnd('test');

    }, 1000);

  })

And the output is:

interval 997

recursion 824687

test: 1001.831ms

But, if I comment these two lines:

  // if (end === false)

  //  setImmediate(loop);

The results are:

interval 537

recursion 1

test: 1003.882ms

I studied hard the phases of nodejs but I don't understand why a setImmediate should impact on the results of the interval function.

Do you have some explanations?

Thank you

asked Nov 21 '18 at 12:34

Manuel Spigolon

1,61611832

I am not an expert of Node.js event loop, however here it is stated that " If the poll phase becomes idle and scripts have been queued with setImmediate(), the event loop may continue to the check phase rather than waiting". So maybe that milliseconds difference is due to the check phase activity added by the setImmediate() invocation.

– P3trur0
Nov 23 '18 at 16:10

But I'm looking that the interval result are: 997 i++ vs 537 i++ without setImmediate, the timing is ok 1 sec

– Manuel Spigolon
Nov 23 '18 at 16:15

The recursion values are right (because in the second test I don't do that) but this shouldn't impact on setInterval (i think..)

– Manuel Spigolon
Nov 23 '18 at 16:17

interesting find...it replicates in the browser as well, with even smaller numbers for the interval

– mihai
Nov 28 '18 at 13:40

Tried also node 10 and 11 and same behaviour, I'm still investigating using inspector

– Manuel Spigolon
Dec 3 '18 at 20:42

add a comment |

I'm running on node 8.11 this test script:

let end = false;



let i = 0;

setInterval(() => { i++; }).unref();





let k = 0;

async function loop() {

  k++

  if (end === false)

    setImmediate(loop);

}



console.time('test');

loop()

  .then(() => {

    setTimeout(() => {

      end = true;

      console.log('interval', i);

      console.log('recursion', k);

      console.timeEnd('test');

    }, 1000);

  })

And the output is:

interval 997

recursion 824687

test: 1001.831ms

But, if I comment these two lines:

  // if (end === false)

  //  setImmediate(loop);

The results are:

interval 537

recursion 1

test: 1003.882ms

I studied hard the phases of nodejs but I don't understand why a setImmediate should impact on the results of the interval function.

Do you have some explanations?

Thank you

asked Nov 21 '18 at 12:34

Manuel Spigolon

1,61611832

I am not an expert of Node.js event loop, however here it is stated that " If the poll phase becomes idle and scripts have been queued with setImmediate(), the event loop may continue to the check phase rather than waiting". So maybe that milliseconds difference is due to the check phase activity added by the setImmediate() invocation.

– P3trur0
Nov 23 '18 at 16:10

But I'm looking that the interval result are: 997 i++ vs 537 i++ without setImmediate, the timing is ok 1 sec

– Manuel Spigolon
Nov 23 '18 at 16:15

The recursion values are right (because in the second test I don't do that) but this shouldn't impact on setInterval (i think..)

– Manuel Spigolon
Nov 23 '18 at 16:17

interesting find...it replicates in the browser as well, with even smaller numbers for the interval

– mihai
Nov 28 '18 at 13:40

Tried also node 10 and 11 and same behaviour, I'm still investigating using inspector

– Manuel Spigolon
Dec 3 '18 at 20:42

add a comment |

I'm running on node 8.11 this test script:

let end = false;



let i = 0;

setInterval(() => { i++; }).unref();





let k = 0;

async function loop() {

  k++

  if (end === false)

    setImmediate(loop);

}



console.time('test');

loop()

  .then(() => {

    setTimeout(() => {

      end = true;

      console.log('interval', i);

      console.log('recursion', k);

      console.timeEnd('test');

    }, 1000);

  })

And the output is:

interval 997

recursion 824687

test: 1001.831ms

But, if I comment these two lines:

  // if (end === false)

  //  setImmediate(loop);

The results are:

interval 537

recursion 1

test: 1003.882ms

I studied hard the phases of nodejs but I don't understand why a setImmediate should impact on the results of the interval function.

Do you have some explanations?

Thank you

asked Nov 21 '18 at 12:34

Manuel Spigolon

1,61611832

I'm running on node 8.11 this test script:

let end = false;



let i = 0;

setInterval(() => { i++; }).unref();





let k = 0;

async function loop() {

  k++

  if (end === false)

    setImmediate(loop);

}



console.time('test');

loop()

  .then(() => {

    setTimeout(() => {

      end = true;

      console.log('interval', i);

      console.log('recursion', k);

      console.timeEnd('test');

    }, 1000);

  })

And the output is:

interval 997

recursion 824687

test: 1001.831ms

But, if I comment these two lines:

  // if (end === false)

  //  setImmediate(loop);

The results are:

interval 537

recursion 1

test: 1003.882ms

I studied hard the phases of nodejs but I don't understand why a setImmediate should impact on the results of the interval function.

Do you have some explanations?

Thank you

node.js performance event-loop

asked Nov 21 '18 at 12:34

Manuel Spigolon

1,61611832

asked Nov 21 '18 at 12:34

Manuel Spigolon

1,61611832

asked Nov 21 '18 at 12:34

Manuel Spigolon

1,61611832

asked Nov 21 '18 at 12:34

Manuel Spigolon

1,61611832

asked Nov 21 '18 at 12:34

Manuel Spigolon

1,61611832

I am not an expert of Node.js event loop, however here it is stated that " If the poll phase becomes idle and scripts have been queued with setImmediate(), the event loop may continue to the check phase rather than waiting". So maybe that milliseconds difference is due to the check phase activity added by the setImmediate() invocation.

– P3trur0
Nov 23 '18 at 16:10

But I'm looking that the interval result are: 997 i++ vs 537 i++ without setImmediate, the timing is ok 1 sec

– Manuel Spigolon
Nov 23 '18 at 16:15

The recursion values are right (because in the second test I don't do that) but this shouldn't impact on setInterval (i think..)

– Manuel Spigolon
Nov 23 '18 at 16:17

interesting find...it replicates in the browser as well, with even smaller numbers for the interval

– mihai
Nov 28 '18 at 13:40

Tried also node 10 and 11 and same behaviour, I'm still investigating using inspector

– Manuel Spigolon
Dec 3 '18 at 20:42

add a comment |

I am not an expert of Node.js event loop, however here it is stated that " If the poll phase becomes idle and scripts have been queued with setImmediate(), the event loop may continue to the check phase rather than waiting". So maybe that milliseconds difference is due to the check phase activity added by the setImmediate() invocation.

– P3trur0
Nov 23 '18 at 16:10

But I'm looking that the interval result are: 997 i++ vs 537 i++ without setImmediate, the timing is ok 1 sec

– Manuel Spigolon
Nov 23 '18 at 16:15

The recursion values are right (because in the second test I don't do that) but this shouldn't impact on setInterval (i think..)

– Manuel Spigolon
Nov 23 '18 at 16:17

interesting find...it replicates in the browser as well, with even smaller numbers for the interval

– mihai
Nov 28 '18 at 13:40

Tried also node 10 and 11 and same behaviour, I'm still investigating using inspector

– Manuel Spigolon
Dec 3 '18 at 20:42

I am not an expert of Node.js event loop, however here it is stated that " If the poll phase becomes idle and scripts have been queued with setImmediate(), the event loop may continue to the check phase rather than waiting". So maybe that milliseconds difference is due to the check phase activity added by the setImmediate() invocation.

– P3trur0
Nov 23 '18 at 16:10

But I'm looking that the interval result are: 997 i++ vs 537 i++ without setImmediate, the timing is ok 1 sec

– Manuel Spigolon
Nov 23 '18 at 16:15

The recursion values are right (because in the second test I don't do that) but this shouldn't impact on setInterval (i think..)

– Manuel Spigolon
Nov 23 '18 at 16:17

interesting find...it replicates in the browser as well, with even smaller numbers for the interval

– mihai
Nov 28 '18 at 13:40

Tried also node 10 and 11 and same behaviour, I'm still investigating using inspector

– Manuel Spigolon
Dec 3 '18 at 20:42

add a comment |

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