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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 identi-
	     fier.  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 re-
     ceive 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  re-
     ceive 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 mes-
     sage.

     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)

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