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Inside Macintosh: Memory /

Chapter 1 - Introduction to Memory Management / Memory Management Reference

Memory Management Routines / Managing Relocatable Blocks

HLockHi

You can use the HLockHi procedure to move a relocatable block to the top of the heap and lock it.

PROCEDURE HLockHi (h: Handle);

h

A handle to a relocatable block.

DESCRIPTION

The HLockHi procedure attempts to move the relocatable block referenced by the handle h upward until it reaches a nonrelocatable block, a locked relocatable block, or the top of the heap. Then HLockHi locks the block.

The HLockHi procedure is simply a convenient replacement for the pair of procedures MoveHHi and HLock.

SPECIAL CONSIDERATIONS

Because the HLockHi procedure moves memory, you should not call it at interrupt time.

Don't call HLockHi on blocks in the system heap. Don't call HLockHi from a desk accessory.

ASSEMBLY-LANGUAGE INFORMATION

The registers on entry and exit for HLockHi are

Registers on entry
A0	Handle to move and lock

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
nilHandleErr	-109	NIL master pointer
memWZErr	-111	Attempt to operate on a free block
memLockedErr	-117	Block is locked