NAME¶
pvm_freebuf - Disposes of a message buffer.
SYNOPSIS¶
C int info = pvm_freebuf( int bufid )
Fortran call pvmffreebuf( bufid, info )
PARAMETERS¶
- bufid
- Integer message buffer identifier.
- info
- Integer status code returned by the routine. Values less than zero
indicate an error.
DESCRIPTION¶
The routine
pvm_freebuf frees the memory associated with the message
buffer identified by
bufid. Message buffers are created by pvm_mkbuf,
pvm_initsend, and pvm_recv. If pvm_freebuf is successful,
info will be
0. If some error occurs then
info will be < 0.
pvm_freebuf can be called for a send buffer created by pvm_mkbuf after the
message has been sent and is no longer needed.
Receive buffers typically do not have to be freed unless they have been saved in
the course of using multiple buffers. But pvm_freebuf can be used to destroy
receive buffers as well. So messages that arrive but are no longer needed can
be destroyed so they will not consume buffer space.
Typically multiple send and receive buffers are not needed and the user can
simply use the pvm_initsend routine to reset the default send buffer.
There are several cases where multiple buffers are useful. One example where
multiple message buffers are needed involves libraries or graphical interfaces
that use PVM and interact with a running PVM application but do not want to
interfere with the application's own communication.
When multiple buffers are used they generally are made and freed for each
message that is packed. In fact, pvm_initsend simply does a pvm_freebuf
followed by a pvm_mkbuf for the default buffer.
EXAMPLES¶
C:
bufid = pvm_mkbuf( PvmDataDefault );
:
info = pvm_freebuf( bufid );
Fortran:
CALL PVMFMKBUF( PVMDEFAULT, BUFID )
:
CALL PVMFFREEBUF( BUFID, INFO )
ERRORS¶
These error conditions can be returned by
pvm_freebuf
- PvmBadParam
- giving an invalid argument value.
- PvmNoSuchBuf
- giving an invalid bufid value.
SEE ALSO¶
pvm_mkbuf(3PVM), pvm_initsend(3PVM), pvm_recv(3PVM)