NAME

AvailMem: memory available given certain requirements

SYNOPSIS

size = AvailMem(attributes)
D0 D1

ULONG AvailMem(ULONG);

FUNCTION

This function returns the amount of free memory given certain attributes.

To find out what the largest block of a particular type is, add MEMF_LARGEST into the requirements argument. Returning the largest block is a slow operation.

WARNING

Memory allocation and deallocation as well as querying how much memory is available requires a Task or, by extension, a Process. None of the exec kernel memory management operations is safe to call from interrupt code!

Due to the effect of multitasking, the value returned may not actually be the amount of free memory available at that instant.

NOTES

Starting with Kickstart 2.0 (V36) AvailMem(MEMF_LARGEST) does a consistency check on the memory list. Alert AN_MemoryInsane will be pulled if any mismatch is noted.

INPUTS

requirements: a requirements mask as specified in AllocMem. Any of the AllocMem bits are valid, as is MEMF_LARGEST which returns the size of the largest block matching the requirements.

RESULT

size: total free space remaining (or the largest free block).

EXAMPLE

/* return size of largest available chip memory chunk */
AvailMem(MEMF_CHIP|MEMF_LARGEST);