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#include <err.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/event.h>
#include <sys/time.h>
/*
* External test set-up code is expected to do the equivalent of
* cd $TOPDIR
* mkdir realdir
* mkdir nulldir
* mount -t null $TOPDIR/realdir $TOPDIR/nulldir
* rm -f $TOPDIR/realdir/afile
* touch $TOPDIR/realdir/afile
* then execute this test program:
* ./h_nullmnt $TOPDIR/realdir/afile $TOPDIR/nulldir/afile
*
* The expected result is that the write() to the nullfile will
* queue up a preexisting kevent which will then be detected by
* the (second) call to kevent(); the failure mode is that the
* write()'s extension to the file is not seen, and the kevent
* call times out after 5 seconds.
*
* Clean-up code should undo the null mount and delete everything
* in the test directory.
*/
int main(int argc, char **argv)
{
int watch_file, write_file;
int kq, nev, rsize;
struct timespec timeout;
struct kevent eventlist;
const char outbuf[] = "new\n";
char inbuf[20];
if (argc <= 2)
errx(EXIT_FAILURE, "insufficient args %d", argc);
watch_file = open(argv[1], O_RDONLY);
if (watch_file == -1)
err(EXIT_FAILURE, "failed to open watch_file %s",
argv[1]);
write_file = open(argv[2], O_WRONLY, O_APPEND);
if (write_file == -1)
err(EXIT_FAILURE, "failed to open write_file %s",
argv[2]);
if ((kq = kqueue()) == -1)
err(EXIT_FAILURE, "Cannot create kqueue");
timeout.tv_sec = 5;
timeout.tv_nsec = 0;
EV_SET(&eventlist, watch_file,
EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_CLEAR,
NOTE_WRITE | NOTE_EXTEND, 0, 0);
if (kevent(kq, &eventlist, 1, NULL, 0, NULL) == -1)
err(EXIT_FAILURE, "Failed to set eventlist for fd %d",
watch_file);
rsize = read(watch_file, &inbuf, sizeof(inbuf));
if (rsize)
errx(EXIT_FAILURE, "Ooops we got %d bytes of data!\n", rsize);
write(write_file, &outbuf, sizeof(outbuf) - 1);
nev = kevent(kq, NULL, 0, &eventlist, 1, &timeout);
if (nev == -1)
err(EXIT_FAILURE, "Failed to retrieve event");
errx((nev == 0) ? EXIT_FAILURE : EXIT_SUCCESS,
"Retrieved %d events, first 0x%x", nev, eventlist.flags);
}
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