{{page>en:templates:dpmi}}

====== Int 31H, AH=0DH, AL=03H ======

===== Version =====

1.0

===== Brief =====

Free Serialization on Shared Memory

===== Input =====

  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 |
    
===== Return =====

  if function successful
  Carry flag = clear
  
  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 =====

Releases a shared memory block serialization that was previously obtained with Int 31H Function 0D02H.

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.

===== See also =====

   

===== Note =====

Text based on [[http://www.delorie.com/djgpp/doc/dpmi/]]

{{page>en:templates:dpmi:int}}