libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/release.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
  11
  12 // <shared_mutex>
  13
  14 // template <class Mutex> class shared_lock;
  15
  16 // mutex_type* release() noexcept;
  17
  18 #include <shared_mutex>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22
  23 struct mutex
  24 {
  25     static int lock_count;
  26     static int unlock_count;
  27     void lock_shared() {++lock_count;}
  28     void unlock_shared() {++unlock_count;}
  29 };
  30
  31 int mutex::lock_count = 0;
  32 int mutex::unlock_count = 0;
  33
  34 mutex m;
  35
  36 int main(int, char**)
  37 {
  38     std::shared_lock<mutex> lk(m);
  39     assert(lk.mutex() == &m);
  40     assert(lk.owns_lock() == true);
  41     assert(mutex::lock_count == 1);
  42     assert(mutex::unlock_count == 0);
  43     assert(lk.release() == &m);
  44     assert(lk.mutex() == nullptr);
  45     assert(lk.owns_lock() == false);
  46     assert(mutex::lock_count == 1);
  47     assert(mutex::unlock_count == 0);
  48     static_assert(noexcept(lk.release()), "release must be noexcept");
  49
  50   return 0;
  51 }