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/*++
/* NAME
/* select_bug 1
/* SUMMARY
/* select test program
/* SYNOPSIS
/* select_bug
/* DESCRIPTION
/* select_bug forks child processes that perform select()
/* on a shared socket, and sees if a wakeup affects other
/* processes selecting on a different socket or stdin.
/* DIAGNOSTICS
/* Problems are reported to the standard error stream.
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h> /* bzero() prototype for 44BSD */
/* Utility library. */
#include <msg.h>
#include <vstream.h>
#include <msg_vstream.h>
static pid_t fork_and_read_select(const char *what, int delay, int fd)
{
struct timeval tv;
pid_t pid;
fd_set readfds;
switch (pid = fork()) {
case -1:
msg_fatal("fork: %m");
case 0:
tv.tv_sec = delay;
tv.tv_usec = 0;
FD_ZERO(&readfds);
FD_SET(fd, &readfds);
switch (select(fd + 1, &readfds, (fd_set *) 0, &readfds, &tv)) {
case -1:
msg_fatal("select: %m");
case 0:
msg_info("%s select timed out", what);
exit(0);
default:
msg_info("%s select wakeup", what);
exit(0);
}
default:
return (pid);
}
}
int main(int argc, char **argv)
{
int pair1[2];
int pair2[2];
msg_vstream_init(argv[0], VSTREAM_ERR);
#define DELAY 1
if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair1) < 0)
msg_fatal("socketpair: %m");
if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair2) < 0)
msg_fatal("socketpair: %m");
vstream_printf("Doing multiple select on socket1, then write to it...\n");
vstream_fflush(VSTREAM_OUT);
fork_and_read_select("socket1", DELAY, pair1[0]); /* one */
fork_and_read_select("socket1", DELAY, pair1[0]); /* two */
fork_and_read_select("socket2", DELAY, pair2[0]);
fork_and_read_select("stdin", DELAY, 0);
if (write(pair1[1], "", 1) != 1)
msg_fatal("write: %m");
while (wait((int *) 0) >= 0)
/* void */ ;
return (0);
}
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