| // { dg-do run } |
| // { dg-additional-options "-pthread" { target pthread } } |
| // { dg-require-effective-target c++11 } |
| // { dg-require-gthreads "" } |
| |
| // Copyright (C) 2010-2021 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 3, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License along |
| // with this library; see the file COPYING3. If not see |
| // <http://www.gnu.org/licenses/>. |
| |
| |
| #include <mutex> |
| #include <testsuite_hooks.h> |
| |
| struct unreliable_lock |
| { |
| std::mutex m; |
| std::unique_lock<std::mutex> l; |
| |
| static int count; |
| static int throw_on; |
| static int lock_on; |
| |
| unreliable_lock() : l(m, std::defer_lock) { } |
| |
| ~unreliable_lock() |
| { |
| VERIFY( !l.owns_lock() ); |
| } |
| |
| void lock() |
| { |
| if (count == throw_on) |
| throw throw_on; |
| ++count; |
| l.lock(); |
| } |
| bool try_lock() |
| { |
| if (count == throw_on) |
| throw throw_on; |
| std::unique_lock<std::mutex> l2(m, std::defer_lock); |
| if (count == lock_on) |
| l2.lock(); |
| ++count; |
| return l.try_lock(); |
| } |
| |
| void unlock() |
| { |
| VERIFY( l.owns_lock() ); |
| l.unlock(); |
| } |
| |
| }; |
| |
| int unreliable_lock::count = 0; |
| int unreliable_lock::throw_on = -1; |
| int unreliable_lock::lock_on = -1; |
| |
| void test01() |
| { |
| unreliable_lock l1, l2, l3; |
| |
| try |
| { |
| unreliable_lock::count = 0; |
| int result = std::try_lock(l1, l2, l3); |
| VERIFY( result == -1 ); |
| VERIFY( unreliable_lock::count == 3 ); |
| l1.unlock(); |
| l2.unlock(); |
| l3.unlock(); |
| } |
| catch (...) |
| { |
| VERIFY( false ); |
| } |
| } |
| |
| void test02() |
| { |
| unreliable_lock l1, l2, l3; |
| |
| try |
| { |
| // test behaviour when a lock is already held |
| unreliable_lock::lock_on = 0; |
| while (unreliable_lock::lock_on < 3) |
| { |
| unreliable_lock::count = 0; |
| int failed = std::try_lock(l1, l2, l3); |
| VERIFY( failed == unreliable_lock::lock_on ); |
| ++unreliable_lock::lock_on; |
| } |
| } |
| catch (...) |
| { |
| VERIFY( false ); |
| } |
| } |
| |
| void test03() |
| { |
| unreliable_lock l1, l2, l3; |
| |
| try |
| { |
| // test behaviour when an exception is thrown |
| unreliable_lock::throw_on = 0; |
| while (unreliable_lock::throw_on < 3) |
| { |
| unreliable_lock::count = 0; |
| try |
| { |
| std::try_lock(l1, l2, l3); |
| VERIFY( false ); |
| } |
| catch (int e) |
| { |
| VERIFY( e == unreliable_lock::throw_on ); |
| } |
| ++unreliable_lock::throw_on; |
| } |
| } |
| catch (...) |
| { |
| VERIFY( false ); |
| } |
| } |
| |
| int main() |
| { |
| test01(); |
| test02(); |
| test03(); |
| return 0; |
| } |