1 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2 #include <arpa/inet.h>
3 #include <assert.h>
4 #include <netinet/in.h>
5 #include <pthread.h>
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <sys/socket.h>
9 #include <sys/types.h>
10 #include <unistd.h>
11 
12 struct sockaddr_in addr4;
13 struct sockaddr_in6 addr6;
14 struct sockaddr *addr;
15 socklen_t addrlen;
16 int X;
17 
18 void *ClientThread(void *x) {
19   int c = socket(addr->sa_family, SOCK_STREAM, IPPROTO_TCP);
20   X = 42;
21   if (connect(c, addr, addrlen)) {
22     perror("connect");
23     exit(1);
24   }
25   close(c);
26   return NULL;
27 }
28 
29 int main() {
30   addr4.sin_family = AF_INET;
31   addr4.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
32   addr4.sin_port = INADDR_ANY;
33   addr = (struct sockaddr *)&addr4;
34   addrlen = sizeof(addr4);
35 
36   int s = socket(addr->sa_family, SOCK_STREAM, IPPROTO_TCP);
37   if (s <= 0) {
38     // Try to fall-back to IPv6
39     addr6.sin6_family = AF_INET6;
40     addr6.sin6_addr = in6addr_loopback;
41     addr6.sin6_port = INADDR_ANY;
42     addr = (struct sockaddr *)&addr6;
43     addrlen = sizeof(addr6);
44     s = socket(addr->sa_family, SOCK_STREAM, IPPROTO_TCP);
45   }
46   assert(s > 0);
47 
48   bind(s, addr, addrlen);
49   getsockname(s, addr, &addrlen);
50   listen(s, 10);
51   pthread_t t;
52   pthread_create(&t, 0, ClientThread, 0);
53   int c = accept(s, 0, 0);
54   X = 42;
55   pthread_join(t, 0);
56   close(c);
57   close(s);
58   fprintf(stderr, "OK\n");
59 }
60 
61 // CHECK-NOT: WARNING: ThreadSanitizer: data race
62 
63