[JASS] So, nulling handle variables to prevent leaks?

[JRPereira]

I've heard more than a few people recently say that you're supposed to null out a handle variable even after you call the destroy function on it in order to prevent leaks.

When did this come about? I had never heard about it few years back when I started mapping, only recently now that I've resumed.

Why would this be required?

 

[PurplePoot]

It's been around for as long as I know. <That's ~2 years now>, and I think at least another year or two before that.

And it's required because otherwise, the 4-byte handle index isn't rescycled.

 

[Captain Griffen]

If the reference count on a handle never falls to 0, then it never gets recycled. This means a leak of a handle index (which is likely more than the 4 byte pointer - 4 bytes is nothing). Anyway, local variables have a bug whereby if at the end of the function the local is still pointing to a variable, it doesn't decrement.

It seems that those set by parameters aren't effected, and it should also be noted that it doesn't matter if you null or not for permament handles, since they will never get recycled anyway (eg: heroes that are always revived, etc).

 

[JRPereira]

Thanks for the info. I've gone through my map now and nulled any handle variables after destroying them. I should be relatively leak-free now.

 

[PurgeandFire]

http://www.thehelper.net/forums/showthread.php?t=72317