1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // UNSUPPORTED: no-threads
10 
11 // <thread>
12 
13 // class thread
14 
15 // void join();
16 
17 #include <thread>
18 #include <new>
19 #include <cstdlib>
20 #include <cassert>
21 #include <system_error>
22 #include <atomic>
23 
24 #include "make_test_thread.h"
25 #include "test_macros.h"
26 
27 std::atomic_bool done(false);
28 
29 class G
30 {
31     int alive_;
32 public:
33     static int n_alive;
34     static bool op_run;
35 
G()36     G() : alive_(1) {++n_alive;}
G(const G & g)37     G(const G& g) : alive_(g.alive_) {++n_alive;}
~G()38     ~G() {alive_ = 0; --n_alive;}
39 
operator ()()40     void operator()()
41     {
42         assert(alive_ == 1);
43         assert(n_alive >= 1);
44         op_run = true;
45     }
46 };
47 
48 int G::n_alive = 0;
49 bool G::op_run = false;
50 
foo()51 void foo() { done = true; }
52 
main(int,char **)53 int main(int, char**)
54 {
55     {
56         G g;
57         std::thread t0 = support::make_test_thread(g);
58         assert(t0.joinable());
59         t0.join();
60         assert(!t0.joinable());
61 #ifndef TEST_HAS_NO_EXCEPTIONS
62         try {
63             t0.join();
64             assert(false);
65         } catch (std::system_error const&) {
66         }
67 #endif
68     }
69 #ifndef TEST_HAS_NO_EXCEPTIONS
70     {
71         std::thread t0 = support::make_test_thread(foo);
72         t0.detach();
73         try {
74             t0.join();
75             assert(false);
76         } catch (std::system_error const&) {
77         }
78         // Wait to make sure that the detached thread has started up.
79         // Without this, we could exit main and start destructing global
80         // resources that are needed when the thread starts up, while the
81         // detached thread would start up only later.
82         while (!done) {}
83     }
84 #endif
85 
86   return 0;
87 }
88