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/* Check that writing an inordinate amount of data works (somewhat).
#progos: linux
#output: got: a\nexit: 0\n
This test-case will *not* work on host (or for real): the first
pipemax+1 bytes will be successfully written. It's just for
exercising a rare execution path. */
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include <unistd.h>
#include <sched.h>
#include <signal.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
int pip[2];
int pipemax;
int
process (void *arg)
{
char *s = arg;
char *buf = calloc (pipemax * 100, 1);
int ret;
if (buf == NULL)
abort ();
*buf = *s;
ret = write (pip[1], buf, pipemax * 100);
if (ret != -1 || errno != EFBIG)
{
perror ("write");
abort ();
}
return 0;
}
int
main (void)
{
int retcode;
int pid;
int st = 0;
long stack[16384];
char buf[1];
retcode = pipe (pip);
if (retcode != 0)
{
fprintf (stderr, "Bad pipe %d\n", retcode);
abort ();
}
#ifdef PIPE_MAX
pipemax = PIPE_MAX;
#else
pipemax = fpathconf (pip[1], _PC_PIPE_BUF);
#endif
if (pipemax <= 0)
{
fprintf (stderr, "Bad pipemax %d\n", pipemax);
abort ();
}
pid = clone (process, (char *) stack + sizeof (stack) - 64,
(CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
| SIGCHLD, "ab");
if (pid <= 0)
{
fprintf (stderr, "Bad clone %d\n", pid);
abort ();
}
while ((retcode = read (pip[0], buf, 1)) == 0)
;
if (retcode != 1)
{
fprintf (stderr, "Bad read 1: %d\n", retcode);
abort ();
}
printf ("got: %c\n", buf[0]);
if (close (pip[0]) != 0)
{
perror ("pip close");
abort ();
}
retcode = waitpid (pid, &st, __WALL);
if (retcode != pid || !WIFEXITED (st))
{
fprintf (stderr, "Bad wait %d:%d %x\n", pid, retcode, st);
perror ("errno");
abort ();
}
printf ("exit: %d\n", WEXITSTATUS (st));
return 0;
}
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