1 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2
3 // The test captures what some high-performance networking servers do.
4 // One thread writes to an fd, and another just receives an epoll
5 // notification about the write to synchronize with the first thread
6 // w/o actually reading from the fd.
7
8 #include "../test.h"
9 #include <errno.h>
10 #include <sys/epoll.h>
11 #include <sys/eventfd.h>
12
main()13 int main() {
14 int efd = epoll_create(1);
15 if (efd == -1)
16 exit(printf("epoll_create failed: %d\n", errno));
17 int fd = eventfd(0, 0);
18 if (fd == -1)
19 exit(printf("eventfd failed: %d\n", errno));
20 epoll_event event = {.events = EPOLLIN | EPOLLET};
21 if (epoll_ctl(efd, EPOLL_CTL_ADD, fd, &event))
22 exit(printf("epoll_ctl failed: %d\n", errno));
23 pthread_t th;
24 pthread_create(
25 &th, nullptr,
26 +[](void *arg) -> void * {
27 long long to_add = 1;
28 if (write((long)arg, &to_add, sizeof(to_add)) != sizeof(to_add))
29 exit(printf("write failed: %d\n", errno));
30 return nullptr;
31 },
32 (void *)(long)fd);
33 struct epoll_event events[1] = {};
34 if (epoll_wait(efd, events, 1, -1) != 1)
35 exit(printf("epoll_wait failed: %d\n", errno));
36 close(fd);
37 pthread_join(th, nullptr);
38 close(efd);
39 fprintf(stderr, "DONE\n");
40 }
41
42 // CHECK: DONE
43