Control Run-Time Checks

Types of Run-Time Checks

When you generate MEX code from your MATLAB^® function, the generated code includes the following run-time checks and external calls to MATLAB functions by default:

• Memory integrity checks

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

  Caution

  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.

  Caution

  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 checks	You have already verified that array bounds and dimension checking is unnecessary.
Responsiveness checks	You are sure that you will not need to stop execution of your application using Ctrl+C.
Extrinsic calls	You are using extrinsic calls only for functions that do not affect application results.

How to Disable Run-Time Checks

To explicitly disable run-time checks in the generated MEX function, use one of these approaches:

• In a MEX code configuration object, set the properties IntegrityChecks, ExtrinsicCalls, or ResponsivenessChecks to false, as applicable.

• In the Code Generation Settings dialog box, deselect the Check memory integrity, Enable responsiveness to CTRL+C and graphics refreshing, or Keep extrinsic calls check boxes, as applicable.