Legacy Document

Inside Macintosh: Memory /

Chapter 2 - Memory Manager / Memory Manager Reference

Memory Manager Routines / Manipulating Blocks of Memory

HandAndHand

Use the HandAndHand function to concatenate two relocatable blocks.

FUNCTION HandAndHand (aHndl, bHndl: Handle): OSErr;

aHndl

A handle to the first relocatable block, whose contents do not change but are concatenated to the end of the second relocatable block.

bHndl

A handle to the second relocatable block, whose size the Memory Manager expands so that it can concatenate the information from aHndl to the end of the contents of this block.

DESCRIPTION

The HandAndHand function concatenates the information from the relocatable block to which aHndl is a handle onto the end of the relocatable block to which bHndl is a handle. The aHndl variable remains unchanged.

WARNING

The HandAndHand function dereferences the handle aHndl. You must call the HLock procedure to lock the block before calling HandAndHand. Afterward, you can call the HUnlock procedure to unlock it. Alternatively, you can save the block's original state by calling the HGetState function, lock the block by calling HLock, and then restore the original settings by calling HSetState.

SPECIAL CONSIDERATIONS

Because HandAndHand moves memory, you should not call it at interrupt time.

ASSEMBLY-LANGUAGE INFORMATION

The registers on entry and exit for HandAndHand are

Registers on entry
A0	Handle to be concatenated
A1	Handle to contain itself, data from A0's handle

Registers on exit
A0	Handle to concatenated data
D0	Result code

RESULT CODES

noErr	0	No error
memFullErr	-108	Not enough memory
nilHandleErr	-109	NIL master pointer
memWZErr	-111	Attempt to operate on a free block