RECV(3PVM)							  PVM Version 3.4							RECV(3PVM)

NAME

       pvm_recv - Receive a message.

SYNOPSIS

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

       Fortran	 call pvmfrecv( 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 returns the value of the new active receive buffer identifier.  Values less than zero indicate an error.

DESCRIPTION

       The  routine pvm_recv blocks the process until a message with label msgtag has arrived from tid.  pvm_recv then places the message in a new
       active receive buffer, which also clears the current receive buffer.

       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_recv  will accept a message from any process which has a matching msgtag.  If msgtag = -1 and tid is defined by the user, then pvm_recv
       will accept any message that is sent from process tid.  If tid = -1 and msgtag = -1,  then  pvm_recv  will  accept  any	message  from  any
       process.

       The  PVM  model	guarantees the following about message order.  If task 1 sends message A to task 2, then task 1 sends message B to task 2,
       message A will arrive at task 2 before message B.  Moreover, if both messages arrive before task 2 does a receive, then a wildcard  receive
       will always return message A.

       If  pvm_recv is successful, bufid will be the value of the new active receive buffer identifier.  If some error occurs then bufid will be <
       0.

       pvm_recv is blocking which means the routine waits until a message matching the user specified tid and msgtag values arrives at	the  local
       pvmd. If the message has already arrived then pvm_recv returns immediately with the message.

       Once pvm_recv returns, the data in the message can be unpacked into the user's memory using the unpack routines.

EXAMPLES

       C:
	    tid = pvm_parent();
	    msgtag = 4 ;
	    bufid = pvm_recv( tid, msgtag );
	    info = pvm_upkint( tid_array, 10, 1 );
	    info = pvm_upkint( problem_size, 1, 1 );
	    info = pvm_upkfloat( input_array, 100, 1 );

       Fortran:
	    CALL PVMFRECV( -1, 4, BUFID )
	    CALL PVMFUNPACK( INTEGER4, TIDS, 25, 1, INFO )
	    CALL PVMFUNPACK( REAL8, MATRIX, 100, 100, INFO )

ERRORS

       These error conditions can be returned by pvm_recv

       PvmBadParam
	      giving an invalid tid value, or msgtag < -1.

       PvmSysErr
	      pvmd not responding.

SEE ALSO

       pvm_bufinfo(3PVM), pvm_getminfo(3PVM), pvm_nrecv(3PVM), pvm_unpack(3PVM), pvm_probe(3PVM), pvm_send(3PVM), pvm_mcast(3PVM)

								  30 August, 1993							RECV(3PVM)