Free Shared Memory

Call With

AX = 0D01H
SI:DI = handle of shared memory block to free

Returns

if function successful
Carry flag = clear

if function unsuccessful
Carry flag = set
AX = error code

8023H

invalid handle

Notes

• The shared memory handle becomes invalid after the shared memory block is deallocated, and should not be used in any other function call (such as serialization).

• The host maintains virtual machine use counts and a global use count for each shared memory block. A virtual machine use count is the number of allocation calls (Int 31H Function 0D00H) that have been issued by a particular virtual machine for the shared block, while the global use count corresponds to the number of virtual machines which have access to the block. When a virtual machine use count reaches zero, the clients in that virtual machine no longer have addressability to the shared memory block; when the global use count reaches zero, the shared memory block is destroyed by the host.

• It is the client's responsibility to free any descriptors that it has allocated to map the shared memory block.

• Applications should not depend on this function to release a previous successful serialization for the same shared memory block. Serialization is only released by this function when the virtual machine use count goes to 0 (i.e., the client no longer has access to the shared memory block).