Specifications

Operating System Routines

COM$DRVDEALMEM

Deallocates system dynamic memory.

Module

COMDRVSUB

Input

Location Contents

R0 Address of block to be deallocated

IRP$W_SIZE Size of block in bytes (must be at least 24 bytes

long)

Output

Location Contents

R0 through R11 Preserved

Synchronization

Drivers can call COM$DRVDEALMEM from any IPL. COM$DRVDEALMEM

executes at the caller’s IPL and returns control at that IPL. The caller retains

any spinlocks it held at the time of the call. If called at IPL$_SYNCH or higher,

the routine executes the fork process.

Description

COM$DRVDEALMEM calls EXE$DEANONPAGED to deallocate the buffer

speciﬁed by R0. If COM$DRVDEALMEM cannot deallocate memory at the

caller’s IPL, it transforms the block being deallocated into a fork block and

queues the block in the fork queue. The code that executes in the fork process

then jumps to EXE$DEANONPAGED.

If the buffer to be deallocated is less than FKB$C_LENGTH in size, or its

address is not aligned on a 16-byte boundary, COM$DRVDEALMEM issues a

BADDALRQSZ bugcheck.

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