pvm_freebuf (3PVM)

C	int info = pvm_freebuf( int bufid )


Fortran	call pvmffreebuf( bufid, info )

bufid

Integer message buffer identifier.

info

Integer status code returned by the routine. Values less than zero indicate an error.

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.

C:
	bufid = pvm_mkbuf( PvmDataDefault );
	      :
	info = pvm_freebuf( bufid );

Fortran:
	CALL PVMFMKBUF( PVMDEFAULT, BUFID )
	      :
	CALL PVMFFREEBUF( BUFID, INFO )

These error conditions can be returned by pvm_freebuf

PvmBadParam

giving an invalid argument value.

PvmNoSuchBuf

giving an invalid bufid value.

pvm_mkbuf(3PVM), pvm_initsend(3PVM), pvm_recv(3PVM)