Programmatically interrupt MATLAB on Windows

13 views (last 30 days)
Szabolcs
Szabolcs on 20 May 2013
Edited: Walter Roberson on 8 Jun 2020
When using MATLAB through the GUI, I can easily interrupt a computation by pressing Ctrl-C.
Is there a way to do the same programmatically when using MATLAB through the MATLAB Engine C API?
On Unix systems there is a solution: send a SIGINT signal. This will not kill MATLAB. It'll only interrupt the computation (i.e. exactly what I want). I am looking for a solution that works on Windows.
Use case: this is for a Mathematica-MATLAB interface. I want to be able to forward interrupts from Mathematica to MATLAB. The functionality is working and implemented on Linux/OSX, but I'd prefer to have it for the majority Windows platform as well.
EDIT: I'm also interested in solution that work with the MEX interface. The MEX function would be multi-threaded where the first thread is running an evalc(), and the second is watching for interrupt conditions. How would the second thread interrupt the evalc()? I have less hope for this with MEX than with Engine though.
UPDATE: I still haven't found any way to do this with the Engine interface, but I did find something which might work with MEX. The libut library has a function called utSetInterruptPending(). When running sequentially, utSetInterruptPending(1) will interrupt MATLAB (as tested with calllib()). Does anyone know utSetInterruptPending() is safe to call in a MEX function from a different thread than the main one?
  7 Comments
Iain
Iain on 21 May 2013
I mean if you, in your matlab code, check to see if something has been done, say, a file being written to a known location, and if so, have the matlab code either stop execution, or, say, execute the code in that file.
Szabolcs
Szabolcs on 21 May 2013
@Iain I have no control over the code that's being run, so I can't do that.

Sign in to comment.

Answers (3)

Walter Roberson
Walter Roberson on 20 May 2013
MS Windows XP SP2 and later support POSIX signals including (presumably) SIG_INT.
  2 Comments
Szabolcs
Szabolcs on 20 May 2013
How can I send such a signal? And does MATLAB actually respond to it the same way as on Unix? I did find that Windows should support these signals, but I have not found a way to actually send them to other processes. The signal.h header does not have a kill() function like on Unix.
I did find this too, but that seems to be for command line programs only, and it doesn't seem to work at all when I try (I get a permission denied error).
Walter Roberson
Walter Roberson on 27 Mar 2020
Edited: Walter Roberson on 8 Jun 2020
It looks like the various tools available to send a signal to an id, do so by sending a WM_CLOSE or WM_TERMINATE message. Unfortunately MATLAB would not be able to tell those apart from user request to terminate the program.
I find evidence that console applications can bind in handlers for control-break, but matlab is not generally a console application and I do not know if it does that binding (and I have not seen yet how a different process can provoke it)

Sign in to comment.


Jan
Jan on 21 May 2013
I assume, you do not want to stop the engine temporarily, like Ctrl-C in the application, but kill the job. Then the windows command taskkill will help.
  3 Comments
Jan
Jan on 22 May 2013
What do you expect as internal state of an interrupted engine? When Matlab is not run as application with a GUI, I cannot imagine, what interrupting without killing can be useful for. Do you want to resume later one?
Nilson Martinez-Lopez
Nilson Martinez-Lopez on 27 Mar 2020
I have an example where I'd like to do this. I am running DAQ toolbox audio data input using startBackground(session). This is run from a callback function followed by wait(session). MATLAB is Busy, unless I use CTRL-C to stop it. I'd like to map a button from the UI to stop it in the same manner.

Sign in to comment.


Szabolcs
Szabolcs on 27 Mar 2020
I originally asked this question a very long time ago, when MATLAB only provided a buggy and limited C API (the "MATLAB Engine") for controlling it from another application.
Since then, MATLAB introduced a much better and much more flexible C++ Engine API.
I have not yet used this, but according to the documentation, it does have facilities for asynchronous evaluations and fo interruption.
See FutureResult and its cancel() method.

Products

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!