Using _CEE_HEAP_MANAGER to invoke the alternative Vendor Heap Manager

This environment variable is set by the user or the application to indicate that the Vendor Heap Manager (VHM), identified by the dllname, is to be used to manage the user heap. The format of the environment variable is:

_CEE_HEAP_MANAGER=dllname

Note: This environment variable must be set using one of the following mechanisms:

ENVAR runtime option.
Inside the file specified by the _CEE_ENVFILE or _CEE_ENVFILE_S environment variable.

Either of these locations is before any user code gets control, meaning prior to the static constructors, and/or main getting control. Setting of this environment variable once the user code has begun execution will not activate the VHM, but the value of the environment variable will be updated.