libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.scoped/adopt_lock.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: c++03, c++11, c++14
  11
  12 // <mutex>
  13
  14 // template <class ...Mutex> class scoped_lock;
  15
  16 // scoped_lock(adopt_lock_t, Mutex&...);
  17
  18 #include <mutex>
  19 #include <cassert>
  20 #include "test_macros.h"
  21
  22 struct TestMutex {
  23     bool locked = false;
  24     TestMutex() = default;
  25
  26     void lock() { assert(!locked); locked = true; }
  27     bool try_lock() { if (locked) return false; locked = true; return true; }
  28     void unlock() { assert(locked); locked = false; }
  29
  30     TestMutex(TestMutex const&) = delete;
  31     TestMutex& operator=(TestMutex const&) = delete;
  32 };
  33
  34 int main(int, char**)
  35 {
  36     {
  37         using LG = std::scoped_lock<>;
  38         LG lg(std::adopt_lock);
  39     }
  40     {
  41         TestMutex m1;
  42         using LG = std::scoped_lock<TestMutex>;
  43         m1.lock();
  44         {
  45             LG lg(std::adopt_lock, m1);
  46             assert(m1.locked);
  47         }
  48         assert(!m1.locked);
  49     }
  50     {
  51         TestMutex m1, m2;
  52         using LG = std::scoped_lock<TestMutex, TestMutex>;
  53         m1.lock(); m2.lock();
  54         {
  55             LG lg(std::adopt_lock, m1, m2);
  56             assert(m1.locked && m2.locked);
  57         }
  58         assert(!m1.locked && !m2.locked);
  59     }
  60     {
  61         TestMutex m1, m2, m3;
  62         using LG = std::scoped_lock<TestMutex, TestMutex, TestMutex>;
  63         m1.lock(); m2.lock(); m3.lock();
  64         {
  65             LG lg(std::adopt_lock, m1, m2, m3);
  66             assert(m1.locked && m2.locked && m3.locked);
  67         }
  68         assert(!m1.locked && !m2.locked && !m3.locked);
  69     }
  70
  71
  72   return 0;
  73 }