SPRAY(3SOCKET) Sockets Library Functions SPRAY(3SOCKET)

NAME

spray - scatter data in order to test the network

SYNOPSIS

cc [ flag ... ] file ... -lsocket -lnsl [ library ... ]
#include <rpcsvc/spray.h>

bool_t xdr_sprayarr(XDR *xdrs, sprayarr *objp);


bool_t xdr_spraycumul(XDR *xdrs, spraycumul *objp);

DESCRIPTION

The spray program sends packets to a given machine to test
communications with that machine.


The spray program is not a C function interface, per se, but it can
be accessed using the generic remote procedure calling interface
clnt_call(). See rpc_clnt_calls(3NSL). The program sends a packet to
the called host. The host acknowledges receipt of the packet. The
program counts the number of acknowledgments and can return that
count.


The spray program currently supports the following procedures, which
should be called in the order given:

SPRAYPROC_CLEAR
This procedure clears the counter.


SPRAYPROC_SPRAY
This procedure sends the packet.


SPRAYPROC_GET
This procedure returns the count and the amount of
time since the last SPRAYPROC_CLEAR.

EXAMPLES

Example 1: Using spray()

The following code fragment demonstrates how the spray program is
used:


#include <rpc/rpc.h>
#include <rpcsvc/spray.h>
...
spraycumul spray_result;
sprayarr spray_data;
char buf[100]; /* arbitrary data */
int loop = 1000;
CLIENT *clnt;
struct timeval timeout0 = {0, 0};
struct timeval timeout25 = {25, 0};
spray_data.sprayarr_len = (uint_t)100;
spray_data.sprayarr_val = buf;
clnt = clnt_create("somehost", SPRAYPROG, SPRAYVERS, "netpath");
if (clnt == (CLIENT *)NULL) {
/* handle this error */
}
if (clnt_call(clnt, SPRAYPROC_CLEAR,
xdr_void, NULL, xdr_void, NULL, timeout25)) {
/* handle this error */
}
while (loop- > 0) {
if (clnt_call(clnt, SPRAYPROC_SPRAY,
xdr_sprayarr, &spray_data, xdr_void, NULL, timeout0)) {
/* handle this error */
}
}
if (clnt_call(clnt, SPRAYPROC_GET,
xdr_void, NULL, xdr_spraycumul, &spray_result, timeout25)) {
/* handle this error */
}
printf("Acknowledged %ld of 1000 packets in %d secs %d usecs\n",
spray_result.counter,
spray_result.clock.sec,
spray_result.clock.usec);

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | Unsafe |
+---------------+-----------------+

SEE ALSO

rpc_clnt_calls(3NSL), attributes(7), spray(8)

NOTES

This interface is unsafe in multithreaded applications. Unsafe
interfaces should be called only from the main thread.


A spray program is not useful as a networking benchmark as it uses
unreliable connectionless transports, for example, udp. It can report
a large number of packets dropped, when the drops were caused by the
program sending packets faster than they can be buffered locally,
that is, before the packets get to the network medium.

December 30, 1996 SPRAY(3SOCKET)