Learn more about Parallel Computing Toolbox

Version 4.0 (R2008b) Parallel Computing Toolbox Software

This table summarizes what is new in Version 4.0 (R2008b):

New Features and Changes	Version Compatibility Considerations	Fixed Bugs and Known Problems	Related Documentation at Web Site
Yes Details below	Yes — Details labeled as Compatibility Considerations, below. See also Summary.	Bug Reports Includes fixes	No

New features and changes introduced in this version are

• MATLAB Compiler Product Support for Parallel Computing Toolbox Applications

• spmd Construct

• Composite Objects

• Configuration Validation

• Rerunning Failed Tasks

• Enhanced Job Control with Generic Scheduler Interface

• Changed Function Names for Codistributed Arrays

• Determining if a MATLAB Pool is Open

MATLAB Compiler Product Support for Parallel Computing Toolbox Applications

This release offers the ability to convert Parallel Computing Toolbox applications, using MATLAB^® Compiler™, into executables and shared libraries that can access MATLAB Distributed Computing Server. For information on this update to MATLAB Compiler, see Applications Created with Parallel Computing Toolbox Can Be Compiled.

Limitations

• MATLAB Compiler does not support configurations that use the local scheduler or local workers (i.e., workers that run locally on the desktop machine running the MATLAB client session).

• Compiled Parallel Computing Toolbox applications do not support Simulink software. For a list of other unsupported products, see the Web page http://www.mathworks.com/products/ineligible_programs/.

• When workers are running a task from compiled code, they can execute only compiled code and toolbox code. They cannot execute functions contained in the current directory. Batch and MATLAB pool jobs attempt to change the worker working directory to the client working directory. When noncompiled files in the current directory conflict with compiled versions (for example, M-files with the same name), an error is thrown.

spmd Construct

A new single program multiple data (spmd) language construct allows enhanced interleaving of serial and parallel programming, with interlab communication.

The general form of an spmd statement is:

spmd
    <statements>
end

The block of code represented by <statements> executes in parallel on workers in the MATLAB pool. Data on the labs is available for access from the client via Composite objects. For more information, see the spmd reference page and Using Distributed Arrays, spmd, and Composites.

Compatibility Considerations

Because spmd is a new keyword, it will conflict with any user-defined functions or variables of the same name. If you have any code with functions or variables named spmd, you must rename them.

Composite Objects

Composite objects provide direct access from the client (desktop) program to data that is stored on labs in the MATLAB pool. The data of variables assigned inside an spmd block is available via Composites in the client. When a MATLAB pool is open, you can also create Composites directly from the client using the Composite function. See also Using Distributed Arrays, spmd, and Composites.

Configuration Validation

The Configurations Manager is enhanced with the capability for validating configurations. Open the Configurations Manager on the MATLAB Desktop by clicking Parallel > Manage Configurations. For more information, see Validating Configurations.

Rerunning Failed Tasks

When using a job manager, if a task does not complete due to certain system failures, it can attempt to rerun up to a specified number of times. New properties of a task object to control reruns and access information about rerun attempts are:

• MaximumNumberOfRetries

• AttemptedNumberOfRetries

• FailedAttemptInformation

Enhanced Job Control with Generic Scheduler Interface

The generic scheduler interface now allows you to cancel and destroy jobs and tasks and to investigate the state of a job. The following new properties of the generic scheduler object facilitate these features:

• GetJobStateFcn

• DestroyJobFcn

• DestroyTaskFcn

• CancelJobFcn

• CancelTaskFcn

New toolbox functions to accommodate this ability are:

• getJobSchedulerData

• setJobSchedulerData

For more information on this new functionality, see Managing Jobs.

Changed Function Names for Codistributed Arrays

What was known in previous releases as distributed arrays are henceforth called codistributed arrays. Some functions related to constructing and accessing codistributed arrays have changed names in this release.

Compatibility Considerations

The following table summarizes the changes in function names relating to codistributed arrays. The first three functions behave exactly the same with no change in operation, arguments, etc. The isa function takes the argument 'codistributed' in addition to the array in question.

Old Function Name	New Function Name
distributed	codistributed
distributor	codistributor
dcolon	codcolon
isdistributed	isa(X, 'codistributed')

Determining if a MATLAB Pool is Open

The function matlabpool now allows you to discover if a pool of workers is already open. The form of the command is:

matlabpool size

For more information about this option and others, see the matlabpool reference page.

Version 4.1 (R2009a) Parallel Computing Toolbox Software

Version 3.3 (R2008a) Parallel Computing Toolbox Software

© 1984-2009- The MathWorks, Inc.    -   Site Help   -   Patents   -   Trademarks   -   Privacy Policy   -   Preventing Piracy   -   RSS