mpid_iprobe.tex

刚才是说明 现在是安装程序在 LINUX环境下进行编程的MPICH安装文件

\startmanpage
\mantitle{MPID{\tt \char`\_}Iprobe}{tex}{10/7/2002}
\manname{MPID{\tt \char`\_}Iprobe}
--- Look for a matching request in the receive queue  but do not remove or return it 
\subhead{Synopsis}
\startvb\begin{verbatim}
int MPID_Iprobe( int source, int tag, MPID_Comm *comm, int context_offset, 
                int * flag, MPI_Status *status )

\end{verbatim}
\endvb

\subhead{Input Parameters}
\startarg{source }{rank to match (or {\tt MPI{\tt \char`\_}ANY{\tt \char`\_}SOURCE})
}
\startarg{tag }{Tag to match (or {\tt MPI{\tt \char`\_}ANY{\tt \char`\_}TAG})
}
\startarg{comm }{communicator to match.
}
\startarg{context{\tt \char`\_}offset }{context id offset of communicator to match
}
\par
\subhead{Output Parameter}
\startarg{flag }{true if a matching request was found, false otherwise.
}
\startarg{status }{{\tt MPI{\tt \char`\_}Status} set as defined by {\tt MPI{\tt \char`\_}Iprobe} (only valid when return 
flag is true).
}
\par
\subhead{Return Value}
Error Code.
\par
\subhead{Notes}
Note that the values returned in {\tt status} will be valid for a subsequent
MPI receive operation only if no other thread attempts to receive the same
message.
(See the
discussion of probe in Section 8.7.2 (Clarifications) of the MPI-2 standard.)
\par
Providing the {\tt context{\tt \char`\_}offset} is necessary at this level to support the
way in which the MPICH implementation uses context ids in the implementation
of other operations.  The communicator is present to allow the device
to use message-queues attached to particular communicators or connections
between processes.
\par
Devices that rely solely on polling to make progress should call
MPID{\tt \char`\_}Progress{\tt \char`\_}poke() (or some equivalent function) if a matching request
could not be found.  This insures that progress continues to be made even if
the application is calling MPI{\tt \char`\_}Iprobe() from within a loop not containing
calls to any other MPI functions.
\par
\subhead{Module}
Request
\par
\endmanpage