#include <sys/socket.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <err.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define FIFONAME "fifo.tmp"
#define FT_END 3
#define FT_FIFO 2
#define FT_PIPE 0
#define FT_SOCKETPAIR 1
#define SETUP(fd, rfds, tv) do { \
FD_ZERO(&(rfds)); \
FD_SET((fd), &(rfds)); \
(tv).tv_sec = 0; \
(tv).tv_usec = 0; \
} while (0)
static int filetype;
static const char *
decode_events(int events)
{
return (events ? "set" : "clear");
}
static void
report(int num, const char *state, int expected, int got)
{
if (!expected == !got)
printf("ok %-2d ", num);
else
printf("not ok %-2d", num);
printf(" %s state %s: expected %s; got %s\n",
filetype == FT_PIPE ? "Pipe" :
filetype == FT_SOCKETPAIR ? "Sock" : "FIFO",
state, decode_events(expected), decode_events(got));
fflush(stdout);
}
static pid_t cpid;
static pid_t ppid;
static volatile sig_atomic_t state;
static void
catch(int sig)
{
state++;
}
static void
child(int fd, int num)
{
fd_set rfds;
struct timeval tv;
int fd1, fd2;
char buf[256];
if (filetype == FT_FIFO) {
fd = open(FIFONAME, O_RDONLY | O_NONBLOCK);
if (fd < 0)
err(1, "open for read");
}
if (fd >= FD_SETSIZE)
errx(1, "fd = %d too large for select()", fd);
if (filetype == FT_FIFO) {
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
/*
* This state (a reader for which there has never been a
* writer) is reported quite differently for select() than
* for poll(). select() must see a ready-to-read descriptor
* since read() will see EOF and not block; it cannot
* distinguish this state from the one of a reader for which
* there has been a writer but all writers have gone away
* and all data has been read. poll() and distinguish these
* states by returning POLLHUP only for the latter; it does
* this, although this makes it inconsistent with the
* blockability of read() in the former.
*/
report(num++, "0", 1, FD_ISSET(fd, &rfds));
}
kill(ppid, SIGUSR1);
usleep(1);
while (state != 1)
;
if (filetype != FT_FIFO) {
/*
* The connection cannot be reestablished. Use the code that
* delays the read until after the writer disconnects since
* that case is more interesting.
*/
state = 4;
goto state4;
}
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "1", 0, FD_ISSET(fd, &rfds));
kill(ppid, SIGUSR1);
usleep(1);
while (state != 2)
;
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "2", 1, FD_ISSET(fd, &rfds));
if (read(fd, buf, sizeof buf) != 1)
err(1, "read");
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "2a", 0, FD_ISSET(fd, &rfds));
kill(ppid, SIGUSR1);
usleep(1);
while (state != 3)
;
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "3", 1, FD_ISSET(fd, &rfds));
kill(ppid, SIGUSR1);
/*
* Now we expect a new writer, and a new connection too since
* we read all the data. The only new point is that we didn't
* start quite from scratch since the read fd is not new. Check
* startup state as above, but don't do the read as above.
*/
usleep(1);
while (state != 4)
;
state4:
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "4", 0, FD_ISSET(fd, &rfds));
kill(ppid, SIGUSR1);
usleep(1);
while (state != 5)
;
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "5", 1, FD_ISSET(fd, &rfds));
kill(ppid, SIGUSR1);
usleep(1);
while (state != 6)
;
/*
* Now we have no writer, but should still have data from the old
* writer. Check that we have a data-readable condition, and that
* the data can be read in the usual way.
*/
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "6", 1, FD_ISSET(fd, &rfds));
if (read(fd, buf, sizeof buf) != 1)
err(1, "read");
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "6a", 1, FD_ISSET(fd, &rfds));
if (filetype == FT_FIFO) {
/*
* Check that the readable-data condition is sticky for a
* new reader and for the old reader. We really only have
* a hangup condition, but select() can only see this as
* a readable-data condition for null data. select()
* cannot distinguish this state from the initial state
* where there is a reader but has never been a writer, so
* the following tests (to follow the pattern in pipepoll.c)
* essentially test state 0 again.
*/
fd2 = open(FIFONAME, O_RDONLY | O_NONBLOCK);
if (fd2 < 0)
err(1, "open for read");
fd1 = fd;
fd = fd2;
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "6b", 1, FD_ISSET(fd, &rfds));
fd = fd1;
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "6c", 1, FD_ISSET(fd, &rfds));
close(fd2);
SETUP(fd, rfds, tv);
if (select(fd + 1, &rfds, NULL, NULL, &tv) < 0)
err(1, "select");
report(num++, "6d", 1, FD_ISSET(fd, &rfds));
}
close(fd);
kill(ppid, SIGUSR1);
exit(0);
}
static void
parent(int fd)
{
usleep(1);
while (state != 1)
;
if (filetype == FT_FIFO) {
fd = open(FIFONAME, O_WRONLY | O_NONBLOCK);
if (fd < 0)
err(1, "open for write");
}
kill(cpid, SIGUSR1);
usleep(1);
while (state != 2)
;
if (write(fd, "", 1) != 1)
err(1, "write");
kill(cpid, SIGUSR1);
usleep(1);
while (state != 3)
;
if (close(fd) != 0)
err(1, "close for write");
kill(cpid, SIGUSR1);
usleep(1);
while (state != 4)
;
if (filetype != FT_FIFO)
return;
fd = open(FIFONAME, O_WRONLY | O_NONBLOCK);
if (fd < 0)
err(1, "open for write");
kill(cpid, SIGUSR1);
usleep(1);
while (state != 5)
;
if (write(fd, "", 1) != 1)
err(1, "write");
kill(cpid, SIGUSR1);
usleep(1);
while (state != 6)
;
if (close(fd) != 0)
err(1, "close for write");
kill(cpid, SIGUSR1);
usleep(1);
while (state != 7)
;
}
int
main(void)
{
int fd[2], num;
num = 1;
printf("1..20\n");
fflush(stdout);
signal(SIGUSR1, catch);
ppid = getpid();
for (filetype = 0; filetype < FT_END; filetype++) {
switch (filetype) {
case FT_FIFO:
if (mkfifo(FIFONAME, 0666) != 0)
err(1, "mkfifo");
fd[0] = -1;
fd[1] = -1;
break;
case FT_SOCKETPAIR:
if (socketpair(AF_UNIX, SOCK_STREAM, AF_UNSPEC,
fd) != 0)
err(1, "socketpair");
break;
case FT_PIPE:
if (pipe(fd) != 0)
err(1, "pipe");
break;
}
state = 0;
switch (cpid = fork()) {
case -1:
err(1, "fork");
case 0:
(void)close(fd[1]);
child(fd[0], num);
break;
default:
(void)close(fd[0]);
parent(fd[1]);
break;
}
num += filetype == FT_FIFO ? 12 : 4;
}
(void)unlink(FIFONAME);
return (0);
}
plain