Frees a communication request object
int MPI_Request_free( MPI_Request *request )
- communication request (handle)
This routine is normally used to free persistent requests created with
either MPI_Recv_init or MPI_Send_init and friends. However, it can be
used to free a request created with MPI_Irecv or MPI_Isend and friends;
in that case the use can not use the test/wait routines on the request.
It is permitted to free an active request. However, once freed, you can not
use the request in a wait or test routine (e.g., MPI_Wait).
Notes for Fortran
All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK) have
an additional argument ierr at the end of the argument list. ierr
is an integer and has the same meaning as the return value of the routine
in C. In Fortran, MPI routines are subroutines, and are invoked with the
All MPI objects (e.g., MPI_Datatype, MPI_Comm) are of type INTEGER
All MPI routines (except MPI_Wtime and MPI_Wtick) return an error value;
C routines as the value of the function and Fortran routines in the last
argument. Before the value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job. The error handler
may be changed with MPI_Errhandler_set; the predefined error handler
MPI_ERRORS_RETURN may be used to cause error values to be returned.
Note that MPI does not guarentee that an MPI program can continue past
- No error; MPI routine completed successfully.
- Invalid MPI_Request. Either null or, in the case of a
MPI_Start or MPI_Startall, not a persistent request.
- Invalid argument. Some argument is invalid and is not
identified by a specific error class (e.g., MPI_ERR_RANK).
also: MPI_Isend, MPI_Irecv, MPI_Issend, MPI_Ibsend, MPI_Irsend,
MPI_Recv_init, MPI_Send_init, MPI_Ssend_init, MPI_Rsend_init, MPI_Wait,
MPI_Test, MPI_Waitall, MPI_Waitany, MPI_Waitsome, MPI_Testall, MPI_Testany,