I’m writing a GUI in App Designer to run Simulink simulations in parallel, using parfeval because I need the ability to cancel in-progress tasks. The app has an Abort button that sets a global variable when it is pressed, which the fetchNext loop checks for. The function myFunc runs the Simulink models and does a lot of extra setup and processing as well. Here’s some abbreviated code:
% get or create pool
pool = gcp;

% schedule tasks
futures(1:numIterations) = parallel.FevalFuture;
for p = 1:numIterations
futures(p) = parfeval(@myFunc);
end

% collect results
numCompleted = 0;
timeout = 180; % 3 minute timeout
while numCompleted < numIterations
[completedIdx, results] = fetchNext(futures,timeout);
numCompleted = numCompleted + 1;
% collect results from tasks that didn’t time out
if ~isempty(completedIdx)
workerTasks{completedIdx} = results;
end
% check for abort
if app.abortRequested
break;
end
end

% check for abort
if app.abortRequested
cancel(pool.FevalQueue.QueuedFutures);
cancel(pool.FevalQueue.RunningFutures);
end
This runs fine, and the abort feature works the first time you use it.
Then if you immediately run the code again, several of the tasks come back Failed with the error message "Dot indexing is not supported for variables of this type." If you close down the pool and re-run the program with fresh workers, the problem disappears.
It seems like cancel doesn’t fully delete the job from the threads, and there’s something left over that interferes with new tasks. Has anyone run into this? Am I missing a step when canceling the futures?

Thanks in advance.I’m writing a GUI in App Designer to run Simulink simulations in parallel, using parfeval because I need the ability to cancel in-progress tasks. The app has an Abort button that sets a global variable when it is pressed, which the fetchNext loop checks for. The function myFunc runs the Simulink models and does a lot of extra setup and processing as well. Here’s some abbreviated code:
% get or create pool
pool = gcp;

% schedule tasks
futures(1:numIterations) = parallel.FevalFuture;
for p = 1:numIterations
futures(p) = parfeval(@myFunc);
end

% collect results
numCompleted = 0;
timeout = 180; % 3 minute timeout
while numCompleted < numIterations
[completedIdx, results] = fetchNext(futures,timeout);
numCompleted = numCompleted + 1;
% collect results from tasks that didn’t time out
if ~isempty(completedIdx)
workerTasks{completedIdx} = results;
end
% check for abort
if app.abortRequested
break;
end
end

% check for abort
if app.abortRequested
cancel(pool.FevalQueue.QueuedFutures);
cancel(pool.FevalQueue.RunningFutures);
end
This runs fine, and the abort feature works the first time you use it.
Then if you immediately run the code again, several of the tasks come back Failed with the error message "Dot indexing is not supported for variables of this type." If you close down the pool and re-run the program with fresh workers, the problem disappears.
It seems like cancel doesn’t fully delete the job from the threads, and there’s something left over that interferes with new tasks. Has anyone run into this? Am I missing a step when canceling the futures?

Thanks in advance. I’m writing a GUI in App Designer to run Simulink simulations in parallel, using parfeval because I need the ability to cancel in-progress tasks. The app has an Abort button that sets a global variable when it is pressed, which the fetchNext loop checks for. The function myFunc runs the Simulink models and does a lot of extra setup and processing as well. Here’s some abbreviated code:
% get or create pool
pool = gcp;

% schedule tasks
futures(1:numIterations) = parallel.FevalFuture;
for p = 1:numIterations
futures(p) = parfeval(@myFunc);
end

% collect results
numCompleted = 0;
timeout = 180; % 3 minute timeout
while numCompleted < numIterations
[completedIdx, results] = fetchNext(futures,timeout);
numCompleted = numCompleted + 1;
% collect results from tasks that didn’t time out
if ~isempty(completedIdx)
workerTasks{completedIdx} = results;
end
% check for abort
if app.abortRequested
break;
end
end

% check for abort
if app.abortRequested
cancel(pool.FevalQueue.QueuedFutures);
cancel(pool.FevalQueue.RunningFutures);
end
This runs fine, and the abort feature works the first time you use it.
Then if you immediately run the code again, several of the tasks come back Failed with the error message "Dot indexing is not supported for variables of this type." If you close down the pool and re-run the program with fresh workers, the problem disappears.
It seems like cancel doesn’t fully delete the job from the threads, and there’s something left over that interferes with new tasks. Has anyone run into this? Am I missing a step when canceling the futures?

Thanks in advance. parfeval, appdesigner, parallel.fevalfuture, parallel computing toolbox, cancel MATLAB Answers — New Questions

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