parfevalOnAll

Run function on all workers in background

Syntax

F = parfevalOnAll(backgroundPool,fcn,numFcnOut,X1,...,Xm)

F = parfevalOnAll(fcn,numFcnOut,X1,...,Xm)

Description

F = parfevalOnAll(backgroundPool,fcn,numFcnOut,X1,...,Xm) schedules the function fcn to run on all workers in the background. You can run other code while MATLAB^® is running the function fcn. For more information about workers and the background, see Background Workers.

Note

The backgroundPool has multiple workers only if you have Parallel Computing Toolbox™.

When you use backgroundPool to run code in the background, you do not need to use parfevalOnAll to set up environment variables.

To run a function on all workers in a parallel pool, see parfevalOnAll (Parallel Computing Toolbox).

MATLAB asynchronously evaluates the function fcn on each worker with X1,X2,…,Xm input arguments and returns numFcnOut output arguments.

MATLAB returns the Future object F before the function fcn finishes running on all of the background workers. You can use fetchOutputs to retrieve the results from the future. To stop running the function fcn, use the cancel function. For more information about futures, see Future.

F = parfevalOnAll(fcn,numFcnOut,X1,...,Xm) schedules the function fcn to be run.

MATLAB returns the Future object F before the function fcn finishes running.

Use this syntax in code designed for use with Parallel Computing Toolbox.

• If you do not have Parallel Computing Toolbox, you do not use any parallel resources. The function runs in serial.

• If you have Parallel Computing Toolbox, parfevalOnAll automatically uses parallel resources.

Input Arguments

fcn — Function to run

function handle

Function to run, specified as a function handle.

Example: fcn = @magic

numFcnOut — Number of output arguments requested

nonnegative integer scalar

Number of output arguments requested from function fcn, specified as an nonnegative integer scalar.

numFcnOut is the number of output arguments you request when you run fcn(X1,...,Xm).

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

X1,...,Xm — Input arguments

comma-separated list of variables or expressions

Input arguments, specified as a comma-separated list of variables or expressions.

Output Arguments

F — Output Future

parallel.Future object

Output Future, returned as a parallel.Future object.

• Use fetchOutputs or fetchNext to retrieve results from F.

• Use afterEach or afterAll to run a function when F completes.

Extended Capabilities

Automatic Parallel Support

Accelerate code by automatically running computation in parallel using Parallel Computing Toolbox™.

Usage notes and limitations:

• The syntax parfevalOnAll(fcn,numFcnOut,X1,...,Xm) has automatic parallel support if you have Parallel Computing Toolbox.

For more information, see Run MATLAB Functions with Automatic Parallel Support (Parallel Computing Toolbox).

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.