How to find out which application is causing the computer to sleep?

Question

My computer went to sleep (actually, it looked more like hibernating) in the middle of an active time, without any warning.

In the Event log, the message was:

The system is entering sleep.

Sleep Reason: Application API

It doesn't give any other information. Is there a way to find out which application caused this call?

Solution

Check out https://www.nirsoft.net/utils/computer_turned_on_times.html

Super useful for more than this situation, but a lifeline when trying to troubleshoot sleep / shutdown / hibernate issues.

Comments

[Gnoupi]

@DaveRook It happened only once so far, but I'm curious about ways to diagnose such event, in general.

[Gnoupi]

@DaveRook - I managed to reproduce it. It happens when i play on external monitor (tv). As long as the lid of the laptop is opened, no problem. When I close the lid, it will go to hibernate after around 10 minutes. Easy to circumvent for my personal case, but that doesn't tell the actual culprit.

[fixer1234]

Ancient question just bumped to the home page. It sounds like the culprit is the power options defining the action when the lid is closed.

[Gnoupi]

@fixer1234 Unfortunately those were set to "do nothing". So probably something more hidden

[Gnoupi]

Empirical method. It would be effective ultimately, in the event that this is a problem which is reproducing regularly, though it would consume a LOT of time. So far, it happened to me once only, so it wouldn't be really adapted. Either way, it's more of a last resort.

[Greenonline]

Link only answer.