Send data from worker to client using a data queue
send(
sends a message or data with the value pollablequeue, data)data to the
parallel.pool.PollableDataQueue specified by
pollablequeue. Retrieve the result using
poll(pollablequeue), and return
data as the answer.
Use the send and poll functions together
using a pollable data queue to transfer and retrieve messages or data from different
workers.
parfor-Loop, and Dispatch the Message on the QueueConstruct a DataQueue, and call
afterEach.
q = parallel.pool.DataQueue; afterEach(q, @disp);
parfor-loop, and send a message. The pending message is
passed to the afterEach function, in this example
@disp.
parfor i = 1:3 send(q, i); end;
1
2
3For more details on listening for data using a
DataQueue, see afterEach.
parfor-loop, and Poll for the ResultConstruct a PollableDataQueue.
p = parallel.pool.PollableDataQueue;
parfor-loop, and send a message, such as data with the
value 1.
parfor i = 1 send(p, i); end
parfor Wait Bar Using a Data QueueThis example shows a function that creates a
parfor wait bar. Create a DataQueue,
and use afterEach to specify the
function to execute each time the queue receives data. This example calls a
subfunction that updates the wait bar.
Create a parfor-loop to carry out a computationally
demanding task in MATLAB®. Use send to send some dummy data on each
iteration of the parfor-loop. When the queue receives the
data, afterEach calls
nUpdateWaitbar in the client MATLAB, and you can observe
the wait bar progress.
function a = parforWaitbar D = parallel.pool.DataQueue; h = waitbar(0, 'Please wait ...'); afterEach(D, @nUpdateWaitbar); N = 200; p = 1; parfor i = 1:N a(i) = max(abs(eig(rand(400)))); send(D, i); end function nUpdateWaitbar(~) waitbar(p/N, h); p = p + 1; end end
