SEND(3PVM) — Subroutines
NAME
pvm_send − Immediately sends the data in the active message buffer.
SYNOPSIS
Cint info = pvm_send( int tid, int msgtag )
Fortrancall pvmfsend( tid, msgtag, info )
PARAMETERS
tidInteger task identifier of destination process.
msgtagInteger message tag supplied by the user. msgtag should be >= 0.
infoInteger status code returned by the routine.
DESCRIPTION
The routine pvm_send sends a message stored in the active send buffer to the PVM process identified by tid. msgtag is used to label the content of the message. If pvm_send is successful, info will be 0. If some error occurs then info will be < 0.
The pvm_send routine is asynchronous. Computation on the sending processor resumes as soon as the message is safely on its way to the receiving processor. This is in contrast to synchronous communication, during which computation on the sending processor halts until the matching receive is executed by the receiving processor.
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.
Terminating a PVM task immediately after sending a message or messages from it may result in those messages being lost. To be sure, always call pvm_exit() before stopping.
EXAMPLES
C:
info = pvm_initsend( PvmDataDefault );
info = pvm_pkint( array, 10, 1 );
msgtag = 3 ;
info = pvm_send( tid, msgtag );
Fortran:
CALL PVMFINITSEND(PVMRAW, INFO)
CALL PVMFPACK( REAL8, DATA, 100, 1, INFO )
CALL PVMFSEND( TID, 3, INFO )
ERRORS
These error conditions can be returned by pvm_send
PvmBadParam
giving an invalid tid or a msgtag.
PvmSysErr
pvmd not responding.
PvmNoBuf
no active send buffer. Try pvm_initsend() before send.
SEE ALSO
pvm_initsend(3PVM), pvm_mcast(3PVM), pvm_pack(3PVM), pvm_psend(3PVM), pvm_recv(3PVM)
— 30 August, 1993