Syntax

Description

[idx,B1,B2,...,Bn] = fetchNext(F)waits for an unread FevalFuture in the array of futuresFto finish, and then returns the linear index of that future in arrayFasidx, along with the future’s results inB1,B2,...,Bn. Before this call, the'Read'property of the particular future isfalse; afterward it istrue.

[idx,B1,B2,...,Bn] = fetchNext(F,TIMEOUT)waits no longer thanTIMEOUTseconds for a result to become available. If the timeout expires before any result becomes available, all output arguments are empty.

If there are no futures inFwhose'Read'property isfalse, then an error is reported. You can check whether there are any unread futures usinganyUnread = ~all([F.Read]).

If the element ofFwhich has become finished encountered an error during execution, that error will be thrown byfetchNext. However, that future’s'Read'property is settrue, so that any subsequent calls tofetchNextcan proceed.

Examples

Request several function evaluations, and update a progress bar while waiting for completion.

N = 100;foridx = N:-1:1% Compute the rank of N magic squaresF(idx) = parfeval(@rank,1,magic(idx));end% Build a waitbar to track progressh = waitbar(0,'Waiting for FevalFutures to complete...'); results = zeros(1,N);foridx = 1:N [completedIdx,thisResult] = fetchNext(F);% store the resultresults(completedIdx) = thisResult;% update waitbarwaitbar(idx/N,h,sprintf('Latest result: %d',thisResult));enddelete(h)

Tips

ThefetchNextfunction returns the linear index of the future from its array. If instead, you need the subscript values of a multidimensional array, you can use theind2subfunction to convert the values.

See Also

fetchOutputs|isequal|parfeval|parfevalOnAll|parpool