NSEND (2)

C SYNOPSIS

#include <net.h>

int nsend (struct nmsg *header);
int ntry_send (struct nmsg *header);
int nrecv (struct nmsg *header);
int ntry_recv (struct nmsg *header);

FORTRAN SYNOPSIS

subroutine NSND (nnode, nevent, ntype, nlength, nflags, ndata, ndsize, nmsg, ierror) subroutine NRCV (nevent, ntype, nlength, nflags, ndata, ndsize, nmsg, ierror) integer nevent, ntype, nlength, nflags, ndata(*), ndsize, ierror

<type> nmsg(*)

DESCRIPTION

The network message-passing functions add routing and packetization to the datalink functions, dsend(2) and drecv(2). nrecv() blocks if there is no synchronizing message to receive. nsend() will block if there is no synchronizing receiving process or forwarding process to take its message (see "Blocking").

ntry_send() and ntry_recv() never cause the calling process to block. The message is either immediately transferred, or an error is immediately returned, indicating that the process would have blocked. See nprobe(2) for similar functionality. All of the functions accept a pointer to a network message descriptor which is an extension of the local level message descriptor used by ksend(2) and krecv(2). The network message descriptor is defined in <net.h>.

1i 2i

struct nmsg {
        int     nh_dl_event;
        int     nh_dl_link;
        int     nh_node;
        int     nh_event;
        int     nh_type;
        int     nh_length;
        int     nh_flags;
        int     nh_data[NHDSIZE];
        char    *nh_msg;
};