1 // RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2 // UNSUPPORTED: tvos, watchos
3 // XFAIL: ios && !iossim
4 #include "sanitizer_common/sanitizer_ucontext.h"
5 #include "test.h"
6 
7 char stack[64 * 1024] __attribute__((aligned(16)));
8 
9 ucontext_t uc, orig_uc[2];
10 void *fiber, *orig_fiber[2];
11 
12 const unsigned N = 1000;
13 
14 __attribute__((noinline))
15 void switch0() {
16   __tsan_switch_to_fiber(orig_fiber[0], 0);
17   swapcontext(&uc, &orig_uc[0]);
18 }
19 
20 void func() {
21   for (;;) {
22     switch0();
23     __tsan_switch_to_fiber(orig_fiber[1], 0);
24     swapcontext(&uc, &orig_uc[1]);
25   }
26 }
27 
28 void *Thread(void *x) {
29   orig_fiber[1] = __tsan_get_current_fiber();
30   for (unsigned i = 0; i < N; i++) {
31     barrier_wait(&barrier);
32     __tsan_switch_to_fiber(fiber, 0);
33     swapcontext(&orig_uc[1], &uc);
34     barrier_wait(&barrier);
35   }
36   return 0;
37 }
38 
39 int main() {
40   fiber = __tsan_create_fiber(0);
41   barrier_init(&barrier, 2);
42   pthread_t t;
43   pthread_create(&t, 0, Thread, 0);
44   orig_fiber[0] = __tsan_get_current_fiber();
45   getcontext(&uc);
46   uc.uc_stack.ss_sp = stack;
47   uc.uc_stack.ss_size = sizeof(stack);
48   uc.uc_link = 0;
49   makecontext(&uc, func, 0);
50   for (unsigned i = 0; i < N; i++) {
51     __tsan_switch_to_fiber(fiber, 0);
52     swapcontext(&orig_uc[0], &uc);
53     barrier_wait(&barrier);
54     barrier_wait(&barrier);
55   }
56   pthread_join(t, 0);
57   __tsan_destroy_fiber(fiber);
58   fprintf(stderr, "PASS\n");
59   return 0;
60 }
61 
62 // CHECK-NOT: WARNING: ThreadSanitizer:
63 // CHECK: PASS
64