Hands-off triggering of Xcode 'Pause'?

Question

Created Dec ’22

Replies 3

Boosts 0

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I have an app that sometimes hangs when the left mouse button is pressed, and resumes when the button is released. The code base is large with complex input handling, and I have no idea where the hang is coming from.

I'm in desperate need of a stack trace and a way to inspect state when this happens, but I can't find a way to suspend the app like this. How can I trigger a Pause operation in the debugger without releasing the mouse or changing app focus? The Metal debugger has a feature to 'Capture in X seconds' - is there something similar for general debugging?

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Answer 1

DTS Engineer OP

Apple

Dec ’22

I have an app that sometimes hangs when the left mouse button is pressed

This is on the Mac, right?

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

0

Answer 2

Decimal OP

Dec ’22

To expand on this, it's a local Mac application running from Xcode. So, the question is really about how to trigger a pause in the debugger without disturbing the application state.

0

Answer 3

DTS Engineer OP

Apple

Dec ’22

On the Mac you can do this:

Run your app from Xcode
In Terminal, run this command:
```
% sleep 5 ; kill -STOP PPP
```
where PPP is the process ID of your app.
Now get the app into the state that’s causing the problem.

After 5 seconds Terminal will send a SIGSTOP to your app and that’ll get you into the debugger.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

0