Free Serialization on Shared Memory

Call With

AX = 0D03H
SI:DI = shared memory block handle
DX = option flags

Bit	Significance
0	0 = release exclusive serialization
	1 = release shared serialization
1	0 = don't free pending serialization
	1 = free pending serialization (see Note)
2-15	reserved, must be zero

if function unsuccessful
Carry flag = set
AX = error code

8002H	invalid state (client does not own a successful serialization of the specified type)
8023H	invalid handle

Notes

• For each client, the DPMI host maintains four different local (virtual machine) serialization counts (exclusive, shared, pending shared, and pending exclusive) for each shared memory block, as well as a global serialization count. The global serialization count is only updated when the sum of a virtual machine's exclusive and shared serialization counts goes from 0 to 1 (serialize) or 1 to 0 (free).

• A client's interrupt handler can call this function with bit 1 of DX set to cancel a serialization request that has suspended the main thread of execution of the same client. In such cases, the original serialization request will return with the Carry flag set and AX = 8005H.