MCR Shared option in deploytool

Hi everybody!

I have a question about the Matlab deploy-tool. When using it to produce a Java .jar file there is an option, available to check - Object instances share MCR.

What is this option for? When should I use it? I tried to find some answers at the help files, but found nothing useful. Thank you in advance for your help!

Answer 1

[Walter Roberson]

According to the documentation,

Shared MCR Instance — When using MATLAB Builder NE, you can create a shared MCR instance, also known as a singleton. The builder creates a single MCR instance for each MATLAB Builder NE component in an application. You can reuse this instance by sharing it among all subsequent class instances within the component. Such sharing results in more efficient memory usage and eliminates the MCR startup cost in each subsequent class instantiation. All class instances share a single MATLAB workspace and share global variables in the MATLAB files used to build the component.

The downside of this is mentioned in a recommendation in a blog:

Don't create or use non-constant static state anywhere (in M, C++ or Java code). Code that uses global variables, for example, will likely yield unexpected results if other applications share the MCR's global resources.

[Artik Crazy]

Thank you for your answer!