| // Support for concurrent programing -*- C++ -*- |
| |
| // Copyright (C) 2003-2020 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. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| /** @file ext/concurrence.h |
| * This file is a GNU extension to the Standard C++ Library. |
| */ |
| |
| #ifndef _CONCURRENCE_H |
| #define _CONCURRENCE_H 1 |
| |
| #pragma GCC system_header |
| |
| #include <exception> |
| #include <bits/gthr.h> |
| #include <bits/functexcept.h> |
| #include <bits/cpp_type_traits.h> |
| #include <ext/type_traits.h> |
| |
| namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| // Available locking policies: |
| // _S_single single-threaded code that doesn't need to be locked. |
| // _S_mutex multi-threaded code that requires additional support |
| // from gthr.h or abstraction layers in concurrence.h. |
| // _S_atomic multi-threaded code using atomic operations. |
| enum _Lock_policy { _S_single, _S_mutex, _S_atomic }; |
| |
| // Compile time constant that indicates prefered locking policy in |
| // the current configuration. |
| static const _Lock_policy __default_lock_policy = |
| #ifndef __GTHREADS |
| _S_single; |
| #elif defined _GLIBCXX_HAVE_ATOMIC_LOCK_POLICY |
| _S_atomic; |
| #else |
| _S_mutex; |
| #endif |
| |
| // NB: As this is used in libsupc++, need to only depend on |
| // exception. No stdexception classes, no use of std::string. |
| class __concurrence_lock_error : public std::exception |
| { |
| public: |
| virtual char const* |
| what() const throw() |
| { return "__gnu_cxx::__concurrence_lock_error"; } |
| }; |
| |
| class __concurrence_unlock_error : public std::exception |
| { |
| public: |
| virtual char const* |
| what() const throw() |
| { return "__gnu_cxx::__concurrence_unlock_error"; } |
| }; |
| |
| class __concurrence_broadcast_error : public std::exception |
| { |
| public: |
| virtual char const* |
| what() const throw() |
| { return "__gnu_cxx::__concurrence_broadcast_error"; } |
| }; |
| |
| class __concurrence_wait_error : public std::exception |
| { |
| public: |
| virtual char const* |
| what() const throw() |
| { return "__gnu_cxx::__concurrence_wait_error"; } |
| }; |
| |
| // Substitute for concurrence_error object in the case of -fno-exceptions. |
| inline void |
| __throw_concurrence_lock_error() |
| { _GLIBCXX_THROW_OR_ABORT(__concurrence_lock_error()); } |
| |
| inline void |
| __throw_concurrence_unlock_error() |
| { _GLIBCXX_THROW_OR_ABORT(__concurrence_unlock_error()); } |
| |
| #ifdef __GTHREAD_HAS_COND |
| inline void |
| __throw_concurrence_broadcast_error() |
| { _GLIBCXX_THROW_OR_ABORT(__concurrence_broadcast_error()); } |
| |
| inline void |
| __throw_concurrence_wait_error() |
| { _GLIBCXX_THROW_OR_ABORT(__concurrence_wait_error()); } |
| #endif |
| |
| class __mutex |
| { |
| private: |
| #if __GTHREADS && defined __GTHREAD_MUTEX_INIT |
| __gthread_mutex_t _M_mutex = __GTHREAD_MUTEX_INIT; |
| #else |
| __gthread_mutex_t _M_mutex; |
| #endif |
| |
| __mutex(const __mutex&); |
| __mutex& operator=(const __mutex&); |
| |
| public: |
| __mutex() |
| { |
| #if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT |
| if (__gthread_active_p()) |
| __GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex); |
| #endif |
| } |
| |
| #if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT |
| ~__mutex() |
| { |
| if (__gthread_active_p()) |
| __gthread_mutex_destroy(&_M_mutex); |
| } |
| #endif |
| |
| void lock() |
| { |
| #if __GTHREADS |
| if (__gthread_active_p()) |
| { |
| if (__gthread_mutex_lock(&_M_mutex) != 0) |
| __throw_concurrence_lock_error(); |
| } |
| #endif |
| } |
| |
| void unlock() |
| { |
| #if __GTHREADS |
| if (__gthread_active_p()) |
| { |
| if (__gthread_mutex_unlock(&_M_mutex) != 0) |
| __throw_concurrence_unlock_error(); |
| } |
| #endif |
| } |
| |
| __gthread_mutex_t* gthread_mutex(void) |
| { return &_M_mutex; } |
| }; |
| |
| class __recursive_mutex |
| { |
| private: |
| #if __GTHREADS && defined __GTHREAD_RECURSIVE_MUTEX_INIT |
| __gthread_recursive_mutex_t _M_mutex = __GTHREAD_RECURSIVE_MUTEX_INIT; |
| #else |
| __gthread_recursive_mutex_t _M_mutex; |
| #endif |
| |
| __recursive_mutex(const __recursive_mutex&); |
| __recursive_mutex& operator=(const __recursive_mutex&); |
| |
| public: |
| __recursive_mutex() |
| { |
| #if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT |
| if (__gthread_active_p()) |
| __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex); |
| #endif |
| } |
| |
| #if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT |
| ~__recursive_mutex() |
| { |
| if (__gthread_active_p()) |
| __gthread_recursive_mutex_destroy(&_M_mutex); |
| } |
| #endif |
| |
| void lock() |
| { |
| #if __GTHREADS |
| if (__gthread_active_p()) |
| { |
| if (__gthread_recursive_mutex_lock(&_M_mutex) != 0) |
| __throw_concurrence_lock_error(); |
| } |
| #endif |
| } |
| |
| void unlock() |
| { |
| #if __GTHREADS |
| if (__gthread_active_p()) |
| { |
| if (__gthread_recursive_mutex_unlock(&_M_mutex) != 0) |
| __throw_concurrence_unlock_error(); |
| } |
| #endif |
| } |
| |
| __gthread_recursive_mutex_t* gthread_recursive_mutex(void) |
| { return &_M_mutex; } |
| }; |
| |
| /// Scoped lock idiom. |
| // Acquire the mutex here with a constructor call, then release with |
| // the destructor call in accordance with RAII style. |
| class __scoped_lock |
| { |
| public: |
| typedef __mutex __mutex_type; |
| |
| private: |
| __mutex_type& _M_device; |
| |
| __scoped_lock(const __scoped_lock&); |
| __scoped_lock& operator=(const __scoped_lock&); |
| |
| public: |
| explicit __scoped_lock(__mutex_type& __name) : _M_device(__name) |
| { _M_device.lock(); } |
| |
| ~__scoped_lock() throw() |
| { _M_device.unlock(); } |
| }; |
| |
| #ifdef __GTHREAD_HAS_COND |
| class __cond |
| { |
| private: |
| #if __GTHREADS && defined __GTHREAD_COND_INIT |
| __gthread_cond_t _M_cond = __GTHREAD_COND_INIT; |
| #else |
| __gthread_cond_t _M_cond; |
| #endif |
| |
| __cond(const __cond&); |
| __cond& operator=(const __cond&); |
| |
| public: |
| __cond() |
| { |
| #if __GTHREADS && ! defined __GTHREAD_COND_INIT |
| if (__gthread_active_p()) |
| __GTHREAD_COND_INIT_FUNCTION(&_M_cond); |
| #endif |
| } |
| |
| #if __GTHREADS && ! defined __GTHREAD_COND_INIT |
| ~__cond() |
| { |
| if (__gthread_active_p()) |
| __gthread_cond_destroy(&_M_cond); |
| } |
| #endif |
| |
| void broadcast() |
| { |
| #if __GTHREADS |
| if (__gthread_active_p()) |
| { |
| if (__gthread_cond_broadcast(&_M_cond) != 0) |
| __throw_concurrence_broadcast_error(); |
| } |
| #endif |
| } |
| |
| void wait(__mutex *mutex) |
| { |
| #if __GTHREADS |
| { |
| if (__gthread_cond_wait(&_M_cond, mutex->gthread_mutex()) != 0) |
| __throw_concurrence_wait_error(); |
| } |
| #endif |
| } |
| |
| void wait_recursive(__recursive_mutex *mutex) |
| { |
| #if __GTHREADS |
| { |
| if (__gthread_cond_wait_recursive(&_M_cond, |
| mutex->gthread_recursive_mutex()) |
| != 0) |
| __throw_concurrence_wait_error(); |
| } |
| #endif |
| } |
| }; |
| #endif |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace |
| |
| #endif |