funfs/tests/oplocktest.cc

   1 #include <fcntl.h>
   2 #include <stdio.h>
   3 #include <errno.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <signal.h>
   7
   8 #ifndef F_SETLEASE
   9 #define F_SETLEASE          1024
  10 #endif
  11
  12 #ifndef F_GETLEASE
  13 #define F_GETLEASE          1025
  14 #endif
  15
  16 #ifndef RT_SIGNAL_LEASE
  17 #define RT_SIGNAL_LEASE     33
  18 #endif
  19
  20 #ifndef F_SETSIG
  21 #define F_SETSIG            10
  22 #endif
  23
  24
  25 static volatile sig_atomic_t fd_pending;
  26
  27 static volatile bool want_to_die = false;;
  28
  29 void sighandler_ignore(int signum)
  30 {
  31     fprintf(stderr, "Ignoring signal %d\n", signum);
  32 }
  33
  34 void sighandler_die(int signum)
  35 {
  36     want_to_die = true;
  37 }
  38
  39 static void signal_handler(int sig, siginfo_t *info, void *unused)
  40 {
  41         //BlockSignals(True, sig);
  42         fd_pending = (sig_atomic_t)info->si_fd;
  43
  44         fprintf(stderr, "Got signal %d about fd %d\n", sig, fd_pending);
  45
  46         //signals_received++;
  47 }
  48
  49 int main(int argc, char *argv[])
  50 {
  51     if (argc < 2)
  52         return -1;
  53
  54     struct sigaction act;
  55
  56     act.sa_handler = NULL;
  57     act.sa_sigaction = signal_handler;
  58     act.sa_flags = SA_SIGINFO;
  59     if (sigaction(RT_SIGNAL_LEASE, &act, NULL) != 0) {
  60         fprintf(stderr, "Failed to set up the signal hangler.\n");
  61         return 20;
  62     }
  63
  64     int fd = open(argv[1], O_RDWR);
  65     fprintf(stderr, "Opening '%s' for fd %d\n", argv[1], fd);
  66
  67     signal(SIGINT, sighandler_die);
  68
  69     while (!want_to_die)
  70     {
  71         if (fcntl(fd, F_SETSIG, RT_SIGNAL_LEASE) == -1) {
  72             fprintf(stderr, "Failed to set signal handler for kernel lease\n");
  73         }
  74         if (fcntl(fd, F_SETLEASE, F_RDLCK) == -1) {
  75             fprintf(stderr, "Failed to get a write lock on %s: %s\n",
  76                     argv[1], strerror(errno));
  77         }
  78
  79         pause();
  80
  81         if (!want_to_die)
  82             fprintf(stderr, "Write on fd %d detected!\n", fd_pending);
  83
  84         fd_pending = 0;
  85
  86         if (fcntl(fd, F_SETLEASE, F_UNLCK) == -1) {
  87             fprintf(stderr, "Failed to unlock %s\n", argv[1]);
  88         }
  89     }
  90
  91     close(fd);
  92     fprintf(stderr, "Terminated successfully!\n");
  93 }