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.\" $Id: pvm_freebuf.3,v 1.1 1996/09/23 22:01:16 pvmsrc Exp $
.TH FREEBUF 3PVM "30 August, 1993" "" "PVM Version 3.4"
.SH NAME
pvm_freebuf \- Disposes of a message buffer.
.SH SYNOPSIS
.nf
.ft B
C int info = pvm_freebuf( int bufid )
.br
Fortran call pvmffreebuf( bufid, info )
.fi
.SH PARAMETERS
.IP bufid 0.8i
Integer message buffer identifier.
.br
.IP info
Integer status code returned by the routine.
Values less than zero indicate an error.
.SH DESCRIPTION
The routine
.I pvm_freebuf
frees the memory associated
with the message buffer identified by
.I bufid.
Message buffers are created by pvm_mkbuf, pvm_initsend, and pvm_recv.
If pvm_freebuf is successful,
.I info
will be 0.
If some error occurs then
.I info
will be < 0.
.PP
pvm_freebuf can be called for a send buffer created by pvm_mkbuf
after the message has been sent and is no longer needed.
.PP
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.
.PP
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.
.PP
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.
.PP
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.
.SH EXAMPLES
.nf
C:
bufid = pvm_mkbuf( PvmDataDefault );
:
info = pvm_freebuf( bufid );
.sp
Fortran:
CALL PVMFMKBUF( PVMDEFAULT, BUFID )
:
CALL PVMFFREEBUF( BUFID, INFO )
.fi
.SH ERRORS
These error conditions can be returned by
.I pvm_freebuf
.IP PvmBadParam
giving an invalid argument value.
.IP PvmNoSuchBuf
giving an invalid bufid value.
.PP
.SH SEE ALSO
pvm_mkbuf(3PVM),
pvm_initsend(3PVM),
pvm_recv(3PVM)
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