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   X = 42;
20   int c = socket(addr->sa_family, SOCK_STREAM, IPPROTO_TCP);
21   if (connect(c, addr, addrlen)) {
22     perror("connect");
23     exit(1);
24   }
25   if (send(c, "a", 1, 0) != 1) {
26     perror("send");
27     exit(1);
28   }
29   close(c);
30   return NULL;
31 }
32 
33 int main() {
34   addr4.sin_family = AF_INET;
35   addr4.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
36   addr4.sin_port = INADDR_ANY;
37   addr = (struct sockaddr *)&addr4;
38   addrlen = sizeof(addr4);
39 
40   int s = socket(addr->sa_family, SOCK_STREAM, IPPROTO_TCP);
41   if (s <= 0) {
42     // Try to fall-back to IPv6
43     addr6.sin6_family = AF_INET6;
44     addr6.sin6_addr = in6addr_loopback;
45     addr6.sin6_port = INADDR_ANY;
46     addr = (struct sockaddr *)&addr6;
47     addrlen = sizeof(addr6);
48     s = socket(addr->sa_family, SOCK_STREAM, IPPROTO_TCP);
49   }
50   assert(s > 0);
51 
52   bind(s, addr, addrlen);
53   getsockname(s, addr, &addrlen);
54   listen(s, 10);
55   pthread_t t;
56   pthread_create(&t, 0, ClientThread, 0);
57   int c = accept(s, 0, 0);
58   char buf;
59   while (read(c, &buf, 1) != 1) {
60   }
61   X = 43;
62   close(c);
63   close(s);
64   pthread_join(t, 0);
65   fprintf(stderr, "OK\n");
66 }
67 
68 // CHECK-NOT: WARNING: ThreadSanitizer: data race
69 
70