Calls that post send or receive operations have the same names as the corresponding blocking calls, except that an additional prefix of I (for immediate) indicates that the call is nonblocking.
MPI_Isend(void* buf, int count, MPI_Datatype datatype, int dest, int tag, MPI_Comm comm, MPI_Request *request)
MPI_ISEND(BUF, COUNT, DATATYPE, DEST, TAG, COMM, REQUEST, IERROR)<type> BUF(*)
INTEGER COUNT, DATATYPE, DEST, TAG, COMM, REQUEST, IERROR
MPI_ISEND posts a standard-mode, nonblocking send.
MPI_Irecv(void* buf, int count, MPI_Datatype datatype, int source, int tag, MPI_Comm comm, MPI_Request *request)
MPI_IRECV(BUF, COUNT, DATATYPE, SOURCE, TAG, COMM, REQUEST, IERROR)<type> BUF(*)
INTEGER COUNT, DATATYPE, SOURCE, TAG, COMM, REQUEST, IERROR
MPI_IRECV posts a nonblocking receive.
These calls allocate a request object and return a handle to it in request object, allocation of request. The request is used to query the status of the communication or wait for its completion.
A nonblocking post-send call indicates that the system may start copying data out of the send buffer. The sender must not access any part of the send buffer (neither for loads nor for stores) after a nonblocking send operation is posted, until the complete-send returns.
A nonblocking post-receive indicates that the system may start writing data into the receive buffer. The receiver must not access any part of the receive buffer after a nonblocking receive operation is posted, until the complete-receive returns.
