jehanne/qa/kern/pipering.c

71 lines
1.6 KiB
C

#include <u.h>
#include <libc.h>
int nring = 32;
int niter = 1024;
int debug = 0;
char data[8192];
int i;
int id;
int intr = 0;
void
handler(void *v, char *s)
{
print("%d: %d iterations\n", id, i);
if (intr++ < 16)
noted(NCONT);
exits("too many interrupts");
}
void
main(int argc, char *argv[])
{
int pid;
if (notify(handler)){
sysfatal("notify: %r");
}
if (argc > 1)
nring = strtoull(argv[1], 0, 0);
if (argc > 2)
niter = strtoull(argv[2], 0, 0);
debug = argc > 3;
fprint(2, "Running with %d pipes %d times\n", nring, niter);
int *pfd = malloc(sizeof(int)* nring * 2);
if (pfd == nil)
sysfatal(smprint("alloc %d pipes: %r", nring*2));
for(i = 0; i < nring; i++)
if (pipe(&pfd[i*2]) < 0)
sysfatal(smprint("create pipe pair %d of %d: %r", i, nring));
for(i = 0; debug && i < nring; i++ ) fprint(2, "pfd[%d,%d]\n", pfd[i*2],pfd[i*2+1]);
for(i = 0, id = 0; i < nring-1; i++, id++) {
pid = fork();
if (pid == 0)
break;
if (pid < 0)
sysfatal("fork");
}
if (debug) fprint(2, "Forked. pid %d\n", getpid());
for(i = 0; debug && i < nring; i++ ) fprint(2, "pfd[%d,%d]\n", pfd[i*2],pfd[i*2+1]);
for(i = 0; i < niter; i++) {
if (debug) fprint(2, "%d: write %d\n", id, pfd[(id%nring)*2+1]);
int amt = write(pfd[(id%nring)*2+1], data, sizeof(data));
if (amt < sizeof(data))
sysfatal(smprint("%d: write only got %d of %d: %r", id, amt, sizeof(data)));
if (debug) print("%d: read %d\n", id, pfd[(id%nring)*2]);
amt = read(pfd[(id%nring)*2], data, sizeof(data));
if (amt < sizeof(data))
sysfatal(smprint("%d: read only got %d of %d: %r", id, amt, sizeof(data)));
}
print("PASS\n");
exits("PASS");
}