# Is it legal glfwWaitEventsTimeout(0.020 - glfwGetTime)?

**URL:** <https://discourse.glfw.org/t/is-it-legal-glfwwaiteventstimeout-0-020-glfwgettime/1496>\
**Category:** support\
**Created:** [February 18, 2020, 9:30am UTC](https://discourse.glfw.org/t/is-it-legal-glfwwaiteventstimeout-0-020-glfwgettime/1496 "2020-02-18T09:30:28Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Chretienorthodox](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.glfw.org/chretienorthodox/32/311_2.png) [@Chretienorthodox](https://discourse.glfw.org/u/Chretienorthodox)\
**Post date:** [February 18, 2020, 9:30am UTC](https://discourse.glfw.org/t/is-it-legal-glfwwaiteventstimeout-0-020-glfwgettime/1496/1 "2020-02-18T09:30:29Z")

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Ladies, Gentlemen,  
Please let me ask your help on question matter. Specifically:  
I want that iteration (while function) period be 20 msec. Then in this function I have

```
glfwWaitEventsTimeout(0.020 - glfwGetTime());

```

but (very old) machine throws wizard:  
“Debug Error!  
Program: [program’s path]  
abort() has been called  
(Press Retry to debug the application)”  
I do not see “Retry”. Buttons are in french.  
Please let me ask you: Is my statement legal?

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**Author:** ![dougbinks](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.glfw.org/dougbinks/32/39_2.png) [@dougbinks](https://discourse.glfw.org/u/dougbinks)\
**Post date:** [February 18, 2020, 9:55am UTC](https://discourse.glfw.org/t/is-it-legal-glfwwaiteventstimeout-0-020-glfwgettime/1496/2 "2020-02-18T09:55:49Z")

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The correct approach is to set the period:

```auto
glfwWaitEventsTimeout( 0.02 );

```

[Documentation for glfwWaitEventsTimeout is on this page](https://www.glfw.org/docs/latest/group__window.html#ga605a178db92f1a7f1a925563ef3ea2cf).

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<div class="post-metadata">

**Author:** ![Chretienorthodox](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.glfw.org/chretienorthodox/32/311_2.png) [@Chretienorthodox](https://discourse.glfw.org/u/Chretienorthodox)\
**Post date:** [February 18, 2020, 10:31am UTC](https://discourse.glfw.org/t/is-it-legal-glfwwaiteventstimeout-0-020-glfwgettime/1496/3 "2020-02-18T10:31:59Z")

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Dear Doug Binks,  
Please accept my many thanks for you replied and that immediately.  
Regards.