xref: /llvm-project/libcxx/test/std/thread/thread.jthread/detach.pass.cpp (revision 121ed5c1985356436d0040dbe81bca26992b1fae)
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 // UNSUPPORTED: c++03, c++11, c++14, c++17
11 // XFAIL: availability-synchronization_library-missing
12 
13 // void detach();
14 
15 #include <atomic>
16 #include <cassert>
17 #include <chrono>
18 #include <concepts>
19 #include <functional>
20 #include <optional>
21 #include <system_error>
22 #include <thread>
23 #include <type_traits>
24 
25 #include "make_test_thread.h"
26 #include "test_macros.h"
27 
28 int main(int, char**) {
29   // Effects: The thread represented by *this continues execution without the calling thread blocking.
30   {
31     std::atomic_bool start{false};
32     std::atomic_bool done{false};
33     std::optional<std::jthread> jt = support::make_test_jthread([&start, &done] {
34       start.wait(false);
35       done = true;
36     });
37 
38     // If it blocks, it will deadlock here
39     jt->detach();
40 
41     jt.reset();
42 
43     // The other thread continues execution
44     start = true;
45     start.notify_all();
46     while (!done) {
47     }
48   }
49 
50   // Postconditions: get_id() == id().
51   {
52     std::jthread jt = support::make_test_jthread([] {});
53     assert(jt.get_id() != std::jthread::id());
54     jt.detach();
55     assert(jt.get_id() == std::jthread::id());
56   }
57 
58 #if !defined(TEST_HAS_NO_EXCEPTIONS)
59   // Throws: system_error when an exception is required ([thread.req.exception]).
60   // invalid_argument - if the thread is not joinable.
61   {
62     std::jthread jt;
63     try {
64       jt.detach();
65       assert(false);
66     } catch (const std::system_error& err) {
67       assert(err.code() == std::errc::invalid_argument);
68     }
69   }
70 #endif
71 
72   std::this_thread::sleep_for(std::chrono::milliseconds{2});
73   return 0;
74 }
75