Prevent clearing MEX-file from memory
By default, MEX-files are unlocked, meaning you can clear them at any time. Call mexLock to prohibit clearing a MEX-file.
To unlock a MEX-file, you must call mexUnlock. Do not use the munlock function.
mexLock increments a lock count. If you call mexLock n times, call mexUnlock n times to unlock your MEX-file.
See the following examples in matlabroot/extern/examples/mex.