removefilesemaphore.m

Multicore - Parallel Processing on Multiple Cores

function removefilesemaphore(semaphore)
%REMOVEFILESEMAPHORE  Remove semaphore after file access.
%   REMOVEFILESEMAPHORE(SEMAPHORE) removes the semaphore(s) set by function
%   SETFILESEMAPHORE to allow file access for other Matlab processes.
%
%		Example:
%		sem = setfilesemaphore('test.mat');
%		% access file test.mat here
%		dir test.mat.semaphore.*
%		removefilesemaphore(sem);
%
%		Markus Buehren
%		Last modified 21.12.2008
%
%   See also SETFILESEMAPHORE.

checkWaitTime = 0.1;

% remove semaphore files
for fileNr = 1:length(semaphore)
	if existfile(semaphore{fileNr})

		% do not use function deletewithsemaphores.m here!

		% sometimes deletion permission is not given, so try several times to
		% delete the file

		warnID = 'MATLAB:DELETE:Permission';
		warnState = warning('query', warnID);
		warning('off', warnID);

		fileDeleted = false;
		for attemptNr = 1:10
			lastwarn('');
			try
				delete(semaphore{fileNr}); %% file access %%
				if isempty(lastwarn)
					fileDeleted = true;
					break
				end
			catch
				% wait before checking again
				pause(checkWaitTime);
			end
		end
		warning(warnState);

		if ~fileDeleted
			% try one last time with display of warning message
			delete(semaphore{fileNr});
		end
	end
end