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Control Run-Time Checks

Types of Run-Time Checks

The code generated for your MATLAB® functions includes the following run-time checks and external calls to MATLAB functions.

  • Memory integrity checks

    These checks detect violations of memory integrity in code generated for MATLAB functions and stop execution with a diagnostic message.


    These checks are enabled by default. Without memory integrity checks, violations result in unpredictable behavior.

  • Responsiveness checks in code generated for MATLAB functions

    These checks enable periodic checks for Ctrl+C breaks in code generated for MATLAB functions. Enabling responsiveness checks also enables graphics refreshing.


    These checks are enabled by default. Without these checks, the only way to end a long-running execution might be to terminate MATLAB.

  • Extrinsic calls to MATLAB functions

    Extrinsic calls to MATLAB functions, for example to display results, are enabled by default for debugging purposes. For more information about extrinsic functions, see Use the coder.extrinsic Construct.

When to Disable Run-Time Checks

Generally, generating code with run-time checks enabled results in more generated code and slower MEX function execution than generating code with the checks disabled. Similarly, extrinsic calls are time consuming and increase memory usage and execution time. Disabling run-time checks and extrinsic calls usually results in streamlined generated code and faster MEX function execution. The following table lists issues to consider when disabling run-time checks and extrinsic calls.

Consider disabling...Only if...
Memory integrity checksYou have already verified that array bounds and dimension checking is unnecessary.
Responsiveness checksYou are sure that you will not need to stop execution of your application using Ctrl+C.
Extrinsic callsYou are using extrinsic calls only for functions that do not affect application results.

How to Disable Run-Time Checks

You can disable run-time checks explicitly from the project settings dialog box, the command line, or a MEX configuration dialog box.

Disabling Run-Time Checks Using the MATLAB Coder App

  1. To open the Generate dialog box, on the Generate Code page, click the Generate arrow .

  2. Set Build type to MEX.

  3. Click More Settings.

  4. On the Speed tab, clear Ensure memory integrity, Enable responsiveness to CTRL+C and graphics refreshing, or Keep Extrinsic calls, as applicable.

Disabling Run-Time Checks From the Command Line

  1. In the MATLAB workspace, define the MEX configuration object:

    mexcfg = coder.config('mex');

  2. At the command line, set the IntegrityChecks, ExtrinsicCalls, or ResponsivenessChecks properties to false, as applicable:

    mexcfg.IntegrityChecks = false;
    mexcfg.ExtrinsicCalls = false;
    mexcfg.ResponsivenessChecks = false;