pvm_bufinfo(3pvm) [debian man page]

BUFINFO(3PVM)							  PVM Version 3.4						     BUFINFO(3PVM)

NAME

       pvm_bufinfo() - Returns information about a message buffer.

SYNOPSIS

       C    int info = pvm_bufinfo( int bufid, int *bytes, int *msgtag,
       int *tid )

       Fortran	 call pvmfbufinfo( bufid, bytes, msgtag, tid, info )

PARAMETERS

       bufid   Integer specifying a particular message buffer identifier.

       bytes   Integer	returning  the	length	in bytes of the body of the message.  This will be equal to the actual size of the data packed, if
	       PvmDataRaw is used, otherwise it may include pad bytes.

       msgtag  Integer returning the message label.  Useful when the message was received with a wildcard msgtag.

       tid     Integer returning the source of the message.  Useful when the message was received with a wildcard tid.

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

DESCRIPTION

       The routine pvm_bufinfo returns information about the requested message buffer. Typically it is used to	determine  facts  about  the  last
       received message such as its size or source.  pvm_bufinfo is especially useful when an application is able to receive any incoming message,
       and the action taken depends on the source tid and the msgtag associated with the message that comes in first.  If pvm_bufinfo is  success-
       ful, info will be 0.  If some error occurs then info will be < 0.

EXAMPLES

       C:
	    bufid = pvm_recv( -1, -1 );
	    info = pvm_bufinfo( bufid, &bytes, &type, &source );

       Fortran:
	    CALL PVMFRECV( -1, -1, BUFID )
	    CALL PVMFBUFINFO( BUFID, BYTES, TYPE, SOURCE, INFO )

ERRORS

       This error condition can be returned by pvm_bufinfo.

       PvmNoSuchBuf
	      specified buffer does not exist.

       PvmBadParam
	      invalid argument

SEE ALSO

       pvm_recv(3PVM)

								  30 August, 1993						     BUFINFO(3PVM)

PROBE(3PVM)							  PVM Version 3.4						       PROBE(3PVM)

NAME

       pvm_probe - Check if message has arrived.

SYNOPSIS

       C    int bufid = pvm_probe( int tid, int msgtag )

       Fortran	 call pvmfprobe( tid, msgtag, bufid )

PARAMETERS

       tid     Integer task identifier of sending process supplied by the user.

       msgtag  Integer message tag supplied by the user.  msgtag should be >= 0.

       bufid   Integer returning the value of the new active receive buffer identifier.  Values less than zero indicate an error.

DESCRIPTION

       The  routine  pvm_probe	checks	to  see  if a message with label msgtag has arrived from tid.  If a matching message has arrived pvm_probe
       returns a buffer identifier in bufid.  This bufid can be used with pvm_bufinfo to determine information	about  the  message  such  as  its
       source and length.

       If the requested message has not arrived, then pvm_probe returns with a 0 in bufid.  If some error occurs bufid will be < 0.

       A  -1  in msgtag or tid matches anything.  This allows the user the following options.  If tid = -1 and msgtag is defined by the user, then
       pvm_probe will accept a message from any process which has a matching msgtag.  If msgtag =  -1  and  tid  is  defined  by  the  user,  then
       pvm_probe  will accept any message that is sent from process tid.  If tid = -1 and msgtag = -1, then pvm_probe will accept any message from
       any process.

       pvm_probe can be called multiple times to check if a given message has arrived yet. After the message has arrived, pvm_recv must be  called
       before the message can be unpacked into the user's memory using the unpack routines.

EXAMPLES

       C:
	    tid = pvm_parent();
	    msgtag = 4 ;
	    arrived = pvm_probe( tid, msgtag );
	    if ( arrived )
		 info = pvm_bufinfo( arrived, &len, &tag, &tid );
	    else
		 /* go do other computing */

       Fortran:
	    CALL PVMFPROBE( -1, 4, ARRIVED )
	    IF ( ARRIVED .GT. 0 ) THEN
		 CALL PVMFBUFINFO( ARRIVED, LEN, TAG, TID, INFO )
	    ELSE
       *	 GO DO USEFUL WORK
	    ENDIF

ERRORS

       These error conditions can be returned by pvm_probe.

       PvmBadParam
	      giving an invalid tid value or msgtag.

       PvmSysErr
	      pvmd not responding.

SEE ALSO

       pvm_bufinfo(3PVM), pvm_getminfo(3PVM), pvm_nrecv(3PVM), pvm_recv(3PVM), pvm_unpack(3PVM)

								  30 August, 1993						       PROBE(3PVM)