Free Shared Memory

Deallocates a shared memory block.

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:

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