launchd/testing/missed-EVFILT_READ.c

   1 /*
   2  * <rdar://problem/4437060> EVFILT_READ doesn't fire reliably
   3  */
   4
   5 #include <sys/types.h>
   6 #include <sys/time.h>
   7 #include <sys/event.h>
   8 #include <sys/socket.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <fcntl.h>
  13 #include <string.h>
  14 #include <errno.h>
  15
  16 static void do_parent(int thefd);
  17 static void do_child(int thefd);
  18
  19 int main(void)
  20 {
  21         int sp[2];
  22
  23         if (-1 == socketpair(AF_UNIX, SOCK_STREAM, 0, sp)) {
  24                 fprintf(stderr, "socketpair(): %s\n", strerror(errno));
  25                 exit(EXIT_FAILURE);
  26         }
  27
  28         switch (fork()) {
  29         case -1:
  30                 fprintf(stderr, "fork(): %s\n", strerror(errno));
  31                 exit(EXIT_FAILURE);
  32         case 0:
  33                 close(sp[0]);
  34                 do_child(sp[1]);
  35                 break;
  36         default:
  37                 close(sp[1]);
  38                 do_parent(sp[0]);
  39                 break;
  40         }
  41
  42         exit(EXIT_SUCCESS);
  43 }
  44
  45 void
  46 do_child(int thefd)
  47 {
  48         char junk = '\0';
  49
  50         for (;;) {
  51                 if (-1 == write(thefd, &junk, sizeof(junk))) {
  52                         fprintf(stderr, "%d: write(): %s\n", __LINE__, strerror(errno));
  53                         exit(EXIT_FAILURE);
  54                 }
  55                 if (-1 == read(thefd, &junk, sizeof(junk))) {
  56                         fprintf(stderr, "%d: read(): %s\n", __LINE__, strerror(errno));
  57                         exit(EXIT_FAILURE);
  58                 }
  59         }
  60 }
  61
  62 void
  63 do_parent(int thefd)
  64 {
  65         struct timespec timeout = { 5, 0 };
  66         int iter = 0, kq;
  67         struct kevent kev;
  68         char junk = '\0';
  69
  70         if (-1 == (kq = kqueue())) {
  71                 fprintf(stderr, "kqueue(): %s\n", strerror(errno));
  72                 exit(EXIT_FAILURE);
  73         }
  74
  75         EV_SET(&kev, thefd, EVFILT_READ, EV_ADD, 0, 0, NULL);
  76
  77         if (-1 == kevent(kq, &kev, 1, NULL, 0, NULL)) {
  78                 fprintf(stderr, "%d: kevent(): %s\n", __LINE__, strerror(errno));
  79                 exit(EXIT_FAILURE);
  80         }
  81
  82         for (;;) {
  83                 switch (kevent(kq, NULL, 0, &kev, 1, &timeout)) {
  84                 case -1:
  85                         fprintf(stderr, "%d: kevent(): %s\n", __LINE__, strerror(errno));
  86                         exit(EXIT_FAILURE);
  87                 case 0:
  88                         fprintf(stderr, "After %d iterations, 4437060 still exists!\n", iter);
  89                         exit(EXIT_FAILURE);
  90                 case 1:
  91                         break;
  92                 default:
  93                         fprintf(stderr, "kevent should only return -1, 0 or 1 for this case!\n");
  94                         exit(EXIT_FAILURE);
  95                 }
  96
  97                 if (kev.filter != EVFILT_READ) {
  98                         fprintf(stderr, "kevent should return EVFILT_READ!\n");
  99                         exit(EXIT_FAILURE);
 100                 }
 101
 102                 if (-1 == read(thefd, &junk, sizeof(junk))) {
 103                         fprintf(stderr, "read(): %s\n", strerror(errno));
 104                         exit(EXIT_FAILURE);
 105                 }
 106                 if (-1 == write(thefd, &junk, sizeof(junk))) {
 107                         fprintf(stderr, "%d: write(): %s\n", __LINE__, strerror(errno));
 108                         exit(EXIT_FAILURE);
 109                 }
 110                 iter++;
 111         }
 112 }