ASM

RESOURCES

Know if one must lock a resource handle

I was looking over some code in my program and all of a sudden I got nervous. The following bit of code works, but should I be locking resHand& before copying data from it?

resHand&=FN GETRESOURCE(_"GeoJ",id)
err% = SYSERROR
siz& = FN GETHANDLESIZE(resHand&)
LONG IF resHand& <>0 and err%=_false 'NOT err%
  CALL SETRESLOAD(_True)
  CALL LOADRESOURCE(resHand&)
  adr&=PEEK LONG (resHand&)
  recAdr&=@gGrad
  BLOCKMOVE adr&, recAdr&, _bSz
END IF
CALL RELEASERESOURCE(resHand&)

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No. BlockMove does not move memory, and neither does Peek. Locking the handle won't hurt anything, but it simply isn't necessary in this fragment.

In general terms, it *is* a good idea to lock a handle before doing anything "serious" with it. BlockMove, however, is a special case.