# Does MWorks pause for implicit display updates?

**URL:** <https://mworks.discourse.group/t/does-mworks-pause-for-implicit-display-updates/473>\
**Category:** Support\
**Created:** [January 22, 2016, 4:29pm UTC](https://mworks.discourse.group/t/does-mworks-pause-for-implicit-display-updates/473 "2016-01-22T16:29:31Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\
**Post date:** [January 22, 2016, 4:29pm UTC](https://mworks.discourse.group/t/does-mworks-pause-for-implicit-display-updates/473/1 "2016-01-22T16:29:31Z")

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I know that MWorks will pause for explicit update\_stimulus\_display actions. Is this the case for implicit updates for as well?

I’m trying to decide whether it is safe to use a regular timer (“wait” action) within a state to time a digital output. It would be bad if the wait ended during a display update pause.

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**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\
**Post date:** [January 22, 2016, 6:21pm UTC](https://mworks.discourse.group/t/does-mworks-pause-for-implicit-display-updates/473/2 "2016-01-22T18:21:14Z")

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> I know that MWorks will pause for explicit update\_stimulus\_display actions. Is this the case for implicit updates for as well?

No. Display updates are handled on their own thread, which runs in parallel with (and independent of) the main experiment execution thread. By design, explicit updates (initiated via `update_stimulus_display`) pause the main experiment thread until the display update thread has submitted all the relevant drawing commands to the graphics hardware (more precisely, until the equivalent of [glFlush](https://www.opengl.org/sdk/docs/man/html/glFlush.xhtml) has completed). However, there’s no such pause associated with implicit updates (e.g. those initiated by dynamic stimuli), because they are initiated and executed entirely on the display update thread.

Chris

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**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\
**Post date:** [July 19, 2022, 10:12pm UTC](https://mworks.discourse.group/t/does-mworks-pause-for-implicit-display-updates/473/3 "2022-07-19T22:12:56Z")

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