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Inside Macintosh: Memory /

Chapter 3 - Virtual Memory Manager / Virtual Memory Manager Reference

Routines / Virtual Memory Management

UnlockMemory

To undo the effects of either LockMemory or LockMemoryContiguous, use the UnlockMemory function.

FUNCTION UnlockMemory (address: UNIV Ptr; count: LongInt): OSErr;

address

The starting address of the range of memory to be unlocked.

count

The size, in bytes, of the range of memory to be unlocked.

DESCRIPTION

The UnlockMemory function makes the portion of the address space beginning at address and having a size of count bytes movable in real memory and eligible for paging again.

If the address parameter supplied to the UnlockMemory function is not on a page boundary, then it is rounded down to the nearest page boundary. Similarly, if the specified range does not end on a page boundary, the count parameter is rounded up so that the entire range of memory is unlocked.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the UnlockMemory function are

Trap macro	Selector
_MemoryDispatch	$0003

The registers on entry and exit for this routine are

Registers on entry
D0	Selector code
A0	Starting address
A1	Number of bytes to unlock

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
paramErr	-50	Error in parameter list
notLockedErr	-623	Specified range of memory is not locked
interruptsMaskedErr	-624	Called with interrupts masked