llvm-project/libcxx/include/mutex

517 lines
12 KiB
C++

// -*- C++ -*-
//===--------------------------- mutex ------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_MUTEX
#define _LIBCPP_MUTEX
/*
mutex synopsis
namespace std
{
class mutex
{
public:
mutex();
~mutex();
mutex(const mutex&) = delete;
mutex& operator=(const mutex&) = delete;
void lock();
bool try_lock();
void unlock();
typedef pthread_mutex_t* native_handle_type;
native_handle_type native_handle();
};
class recursive_mutex
{
public:
recursive_mutex();
~recursive_mutex();
recursive_mutex(const recursive_mutex&) = delete;
recursive_mutex& operator=(const recursive_mutex&) = delete;
void lock();
bool try_lock();
void unlock();
typedef pthread_mutex_t* native_handle_type;
native_handle_type native_handle();
};
class timed_mutex
{
public:
timed_mutex();
~timed_mutex();
timed_mutex(const timed_mutex&) = delete;
timed_mutex& operator=(const timed_mutex&) = delete;
void lock();
bool try_lock();
template <class Rep, class Period>
bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
template <class Clock, class Duration>
bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
void unlock();
};
class recursive_timed_mutex
{
public:
recursive_timed_mutex();
~recursive_timed_mutex();
recursive_timed_mutex(const recursive_timed_mutex&) = delete;
recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
void lock();
bool try_lock();
template <class Rep, class Period>
bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
template <class Clock, class Duration>
bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
void unlock();
};
struct defer_lock_t {};
struct try_to_lock_t {};
struct adopt_lock_t {};
constexpr defer_lock_t defer_lock{};
constexpr try_to_lock_t try_to_lock{};
constexpr adopt_lock_t adopt_lock{};
template <class Mutex>
class lock_guard
{
public:
typedef Mutex mutex_type;
explicit lock_guard(mutex_type& m);
lock_guard(mutex_type& m, adopt_lock_t);
~lock_guard();
lock_guard(lock_guard const&) = delete;
lock_guard& operator=(lock_guard const&) = delete;
};
template <class Mutex>
class unique_lock
{
public:
typedef Mutex mutex_type;
unique_lock();
explicit unique_lock(mutex_type& m);
unique_lock(mutex_type& m, defer_lock_t);
unique_lock(mutex_type& m, try_to_lock_t);
unique_lock(mutex_type& m, adopt_lock_t);
template <class Clock, class Duration>
unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time);
template <class Rep, class Period>
unique_lock(mutex_type& m, const chrono::duration<Rep, Period>& rel_time);
~unique_lock();
unique_lock(unique_lock const&) = delete;
unique_lock& operator=(unique_lock const&) = delete;
unique_lock(unique_lock&& u);
unique_lock& operator=(unique_lock&& u);
void lock();
bool try_lock();
template <class Rep, class Period>
bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
template <class Clock, class Duration>
bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
void unlock();
void swap(unique_lock& u);
mutex_type* release();
bool owns_lock() const;
explicit operator bool () const;
mutex_type* mutex() const;
};
template <class Mutex>
void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y);
template <class L1, class L2, class... L3>
int try_lock(L1&, L2&, L3&...);
template <class L1, class L2, class... L3>
void lock(L1&, L2&, L3&...);
struct once_flag
{
constexpr once_flag();
once_flag(const once_flag&) = delete;
once_flag& operator=(const once_flag&) = delete;
};
template<class Callable, class ...Args>
void call_once(once_flag& flag, Callable&& func, Args&&... args);
} // std
*/
#include <__config>
#include <__mutex_base>
#include <functional>
#pragma GCC system_header
_LIBCPP_BEGIN_NAMESPACE_STD
class recursive_mutex
{
pthread_mutex_t __m_;
public:
recursive_mutex();
~recursive_mutex();
private:
recursive_mutex(const recursive_mutex&); // = delete;
recursive_mutex& operator=(const recursive_mutex&); // = delete;
public:
void lock();
bool try_lock();
void unlock();
typedef pthread_mutex_t* native_handle_type;
native_handle_type native_handle() {return &__m_;}
};
class timed_mutex
{
mutex __m_;
condition_variable __cv_;
bool __locked_;
public:
timed_mutex();
~timed_mutex();
private:
timed_mutex(const timed_mutex&); // = delete;
timed_mutex& operator=(const timed_mutex&); // = delete;
public:
void lock();
bool try_lock();
template <class _Rep, class _Period>
bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
{return try_lock_until(chrono::monotonic_clock::now() + __d);}
template <class _Clock, class _Duration>
bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
void unlock();
};
template <class _Clock, class _Duration>
bool
timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
{
using namespace chrono;
unique_lock<mutex> __lk(__m_);
bool no_timeout = _Clock::now() < __t;
while (no_timeout && __locked_)
no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
if (!__locked_)
{
__locked_ = true;
return true;
}
return false;
}
class recursive_timed_mutex
{
mutex __m_;
condition_variable __cv_;
size_t __count_;
pthread_t __id_;
public:
recursive_timed_mutex();
~recursive_timed_mutex();
private:
recursive_timed_mutex(const recursive_timed_mutex&); // = delete;
recursive_timed_mutex& operator=(const recursive_timed_mutex&); // = delete;
public:
void lock();
bool try_lock();
template <class _Rep, class _Period>
bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
{return try_lock_until(chrono::monotonic_clock::now() + __d);}
template <class _Clock, class _Duration>
bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
void unlock();
};
template <class _Clock, class _Duration>
bool
recursive_timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
{
using namespace chrono;
pthread_t __id = pthread_self();
unique_lock<mutex> lk(__m_);
if (pthread_equal(__id, __id_))
{
if (__count_ == numeric_limits<size_t>::max())
return false;
++__count_;
return true;
}
bool no_timeout = _Clock::now() < __t;
while (no_timeout && __count_ != 0)
no_timeout = __cv_.wait_until(lk, __t) == cv_status::no_timeout;
if (__count_ == 0)
{
__count_ = 1;
__id_ = __id;
return true;
}
return false;
}
template <class _L0, class _L1>
int
try_lock(_L0& __l0, _L1& __l1)
{
unique_lock<_L0> __u0(__l0, try_to_lock);
if (__u0.owns_lock())
{
if (__l1.try_lock())
{
__u0.release();
return -1;
}
else
return 1;
}
return 0;
}
#ifndef _LIBCPP_HAS_NO_VARIADICS
template <class _L0, class _L1, class _L2, class... _L3>
int
try_lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3)
{
int __r = 0;
unique_lock<_L0> __u0(__l0, try_to_lock);
if (__u0.owns_lock())
{
__r = try_lock(__l1, __l2, __l3...);
if (__r == -1)
__u0.release();
else
++__r;
}
return __r;
}
#endif
template <class _L0, class _L1>
void
lock(_L0& __l0, _L1& __l1)
{
while (true)
{
{
unique_lock<_L0> __u0(__l0);
if (__l1.try_lock())
{
__u0.release();
break;
}
}
sched_yield();
{
unique_lock<_L1> __u1(__l1);
if (__l0.try_lock())
{
__u1.release();
break;
}
}
sched_yield();
}
}
#ifndef _LIBCPP_HAS_NO_VARIADICS
template <class _L0, class _L1, class ..._L2>
void
__lock_first(int __i, _L0& __l0, _L1& __l1, _L2& ...__l2)
{
while (true)
{
switch (__i)
{
case 0:
{
unique_lock<_L0> __u0(__l0);
__i = try_lock(__l1, __l2...);
if (__i == -1)
{
__u0.release();
return;
}
}
++__i;
sched_yield();
break;
case 1:
{
unique_lock<_L1> __u1(__l1);
__i = try_lock(__l2..., __l0);
if (__i == -1)
{
__u1.release();
return;
}
}
if (__i == sizeof...(_L2))
__i = 0;
else
__i += 2;
sched_yield();
break;
default:
__lock_first(__i - 2, __l2..., __l0, __l1);
return;
}
}
}
template <class _L0, class _L1, class ..._L2>
inline
void
lock(_L0& __l0, _L1& __l1, _L2& ...__l2)
{
__lock_first(0, __l0, __l1, __l2...);
}
#endif
struct once_flag;
#ifndef _LIBCPP_HAS_NO_VARIADICS
template<class _Callable, class... _Args>
void call_once(once_flag&, _Callable&&, _Args&&...);
#else
template<class _Callable>
void call_once(once_flag&, _Callable);
#endif
struct once_flag
{
// constexpr
once_flag() {}
private:
once_flag(const once_flag&); // = delete;
once_flag& operator=(const once_flag&); // = delete;
unsigned long __state_;
#ifndef _LIBCPP_HAS_NO_VARIADICS
template<class _Callable, class... _Args>
friend
void call_once(once_flag&, _Callable&&, _Args&&...);
#else
template<class _Callable>
friend
void call_once(once_flag&, _Callable);
#endif
};
template <class _F>
class __call_once_param
{
_F __f_;
public:
#ifdef _LIBCPP_MOVE
explicit __call_once_param(_F&& __f) : __f_(_STD::move(__f)) {}
#else
explicit __call_once_param(const _F& __f) : __f_(__f) {}
#endif
void operator()()
{
__f_();
}
};
template <class _F>
void
__call_once_proxy(void* __vp)
{
__call_once_param<_F>* __p = static_cast<__call_once_param<_F>*>(__vp);
(*__p)();
}
void __call_once(volatile unsigned long&, void*, void(*)(void*));
#ifndef _LIBCPP_HAS_NO_VARIADICS
template<class _Callable, class... _Args>
inline _LIBCPP_INLINE_VISIBILITY
void
call_once(once_flag& __flag, _Callable&& __func, _Args&&... __args)
{
if (__builtin_expect(__flag.__state_ , ~0ul) != ~0ul)
{
typedef decltype(std::bind(std::forward<_Callable>(__func),
std::forward<_Args>(__args)...)) _G;
__call_once_param<_G> __p(std::bind(std::forward<_Callable>(__func),
std::forward<_Args>(__args)...));
__call_once(__flag.__state_, &__p, &__call_once_proxy<_G>);
}
}
#else
template<class _Callable>
inline _LIBCPP_INLINE_VISIBILITY
void
call_once(once_flag& __flag, _Callable __func)
{
if (__flag.__state_ != ~0ul)
{
__call_once_param<_Callable> __p(__func);
__call_once(__flag.__state_, &__p, &__call_once_proxy<_Callable>);
}
}
#endif
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_MUTEX