libcxx/test/std/thread/thread.jthread/detach.pass.cpp

   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: libcpp-has-no-experimental-stop_token
  11 // UNSUPPORTED: c++03, c++11, c++14, c++17
  12 // XFAIL: availability-synchronization_library-missing
  13
  14 // void detach();
  15
  16 #include <atomic>
  17 #include <cassert>
  18 #include <chrono>
  19 #include <concepts>
  20 #include <functional>
  21 #include <optional>
  22 #include <system_error>
  23 #include <thread>
  24 #include <type_traits>
  25
  26 #include "make_test_thread.h"
  27 #include "test_macros.h"
  28
  29 int main(int, char**) {
  30   // Effects: The thread represented by *this continues execution without the calling thread blocking.
  31   {
  32     std::atomic_bool start{false};
  33     std::atomic_bool done{false};
  34     std::optional<std::jthread> jt = support::make_test_jthread([&start, &done] {
  35       start.wait(false);
  36       done = true;
  37     });
  38
  39     // If it blocks, it will deadlock here
  40     jt->detach();
  41
  42     jt.reset();
  43
  44     // The other thread continues execution
  45     start = true;
  46     start.notify_all();
  47     while (!done) {
  48     }
  49   }
  50
  51   // Postconditions: get_id() == id().
  52   {
  53     std::jthread jt = support::make_test_jthread([] {});
  54     assert(jt.get_id() != std::jthread::id());
  55     jt.detach();
  56     assert(jt.get_id() == std::jthread::id());
  57   }
  58
  59 #if !defined(TEST_HAS_NO_EXCEPTIONS)
  60   // Throws: system_error when an exception is required ([thread.req.exception]).
  61   // invalid_argument - if the thread is not joinable.
  62   {
  63     std::jthread jt;
  64     try {
  65       jt.detach();
  66       assert(false);
  67     } catch (const std::system_error& err) {
  68       assert(err.code() == std::errc::invalid_argument);
  69     }
  70   }
  71 #endif
  72
  73   std::this_thread::sleep_for(std::chrono::milliseconds{2});
  74   return 0;
  75 }