llvm-project/libcxx/include/mutex

712 lines
17 KiB
C++

// -*- C++ -*-
//===--------------------------- mutex ------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_MUTEX
#define _LIBCPP_MUTEX
/*
mutex synopsis
namespace std
{
class mutex
{
public:
constexpr mutex() noexcept;
~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() noexcept;
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() noexcept;
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 { explicit defer_lock_t() = default; };
struct try_to_lock_t { explicit try_to_lock_t() = default; };
struct adopt_lock_t { explicit adopt_lock_t() = default; };
inline constexpr defer_lock_t defer_lock{};
inline constexpr try_to_lock_t try_to_lock{};
inline 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... MutexTypes>
class scoped_lock // C++17
{
public:
using mutex_type = Mutex; // If MutexTypes... consists of the single type Mutex
explicit scoped_lock(MutexTypes&... m);
scoped_lock(adopt_lock_t, MutexTypes&... m);
~scoped_lock();
scoped_lock(scoped_lock const&) = delete;
scoped_lock& operator=(scoped_lock const&) = delete;
private:
tuple<MutexTypes&...> pm; // exposition only
};
template <class Mutex>
class unique_lock
{
public:
typedef Mutex mutex_type;
unique_lock() noexcept;
explicit unique_lock(mutex_type& m);
unique_lock(mutex_type& m, defer_lock_t) noexcept;
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) noexcept;
unique_lock& operator=(unique_lock&& u) noexcept;
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) noexcept;
mutex_type* release() noexcept;
bool owns_lock() const noexcept;
explicit operator bool () const noexcept;
mutex_type* mutex() const noexcept;
};
template <class Mutex>
void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y) noexcept;
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() noexcept;
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 <cstdint>
#include <functional>
#include <memory>
#ifndef _LIBCPP_CXX03_LANG
#include <tuple>
#endif
#include <version>
#include <__threading_support>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
#ifndef _LIBCPP_HAS_NO_THREADS
class _LIBCPP_TYPE_VIS recursive_mutex
{
__libcpp_recursive_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() _NOEXCEPT;
void unlock() _NOEXCEPT;
typedef __libcpp_recursive_mutex_t* native_handle_type;
_LIBCPP_INLINE_VISIBILITY
native_handle_type native_handle() {return &__m_;}
};
class _LIBCPP_TYPE_VIS 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() _NOEXCEPT;
template <class _Rep, class _Period>
_LIBCPP_INLINE_VISIBILITY
bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
{return try_lock_until(chrono::steady_clock::now() + __d);}
template <class _Clock, class _Duration>
_LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
void unlock() _NOEXCEPT;
};
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 _LIBCPP_TYPE_VIS recursive_timed_mutex
{
mutex __m_;
condition_variable __cv_;
size_t __count_;
__thread_id __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() _NOEXCEPT;
template <class _Rep, class _Period>
_LIBCPP_INLINE_VISIBILITY
bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
{return try_lock_until(chrono::steady_clock::now() + __d);}
template <class _Clock, class _Duration>
_LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
void unlock() _NOEXCEPT;
};
template <class _Clock, class _Duration>
bool
recursive_timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
{
using namespace chrono;
__thread_id __id = this_thread::get_id();
unique_lock<mutex> lk(__m_);
if (__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_CXX03_LANG
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 // _LIBCPP_CXX03_LANG
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;
}
}
__libcpp_thread_yield();
{
unique_lock<_L1> __u1(__l1);
if (__l0.try_lock())
{
__u1.release();
break;
}
}
__libcpp_thread_yield();
}
}
#ifndef _LIBCPP_CXX03_LANG
template <class _L0, class _L1, class _L2, class ..._L3>
void
__lock_first(int __i, _L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
{
while (true)
{
switch (__i)
{
case 0:
{
unique_lock<_L0> __u0(__l0);
__i = try_lock(__l1, __l2, __l3...);
if (__i == -1)
{
__u0.release();
return;
}
}
++__i;
__libcpp_thread_yield();
break;
case 1:
{
unique_lock<_L1> __u1(__l1);
__i = try_lock(__l2, __l3..., __l0);
if (__i == -1)
{
__u1.release();
return;
}
}
if (__i == sizeof...(_L3) + 1)
__i = 0;
else
__i += 2;
__libcpp_thread_yield();
break;
default:
__lock_first(__i - 2, __l2, __l3..., __l0, __l1);
return;
}
}
}
template <class _L0, class _L1, class _L2, class ..._L3>
inline _LIBCPP_INLINE_VISIBILITY
void
lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
{
__lock_first(0, __l0, __l1, __l2, __l3...);
}
template <class _L0>
inline _LIBCPP_INLINE_VISIBILITY
void __unlock(_L0& __l0) {
__l0.unlock();
}
template <class _L0, class _L1>
inline _LIBCPP_INLINE_VISIBILITY
void __unlock(_L0& __l0, _L1& __l1) {
__l0.unlock();
__l1.unlock();
}
template <class _L0, class _L1, class _L2, class ..._L3>
inline _LIBCPP_INLINE_VISIBILITY
void __unlock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
__l0.unlock();
__l1.unlock();
_VSTD::__unlock(__l2, __l3...);
}
#endif // _LIBCPP_CXX03_LANG
#if _LIBCPP_STD_VER > 14
template <class ..._Mutexes>
class _LIBCPP_TEMPLATE_VIS scoped_lock;
template <>
class _LIBCPP_TEMPLATE_VIS scoped_lock<> {
public:
explicit scoped_lock() {}
~scoped_lock() = default;
_LIBCPP_INLINE_VISIBILITY
explicit scoped_lock(adopt_lock_t) {}
scoped_lock(scoped_lock const&) = delete;
scoped_lock& operator=(scoped_lock const&) = delete;
};
template <class _Mutex>
class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable) scoped_lock<_Mutex> {
public:
typedef _Mutex mutex_type;
private:
mutex_type& __m_;
public:
explicit scoped_lock(mutex_type & __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
: __m_(__m) {__m_.lock();}
~scoped_lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}
_LIBCPP_INLINE_VISIBILITY
explicit scoped_lock(adopt_lock_t, mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
: __m_(__m) {}
scoped_lock(scoped_lock const&) = delete;
scoped_lock& operator=(scoped_lock const&) = delete;
};
template <class ..._MArgs>
class _LIBCPP_TEMPLATE_VIS scoped_lock
{
static_assert(sizeof...(_MArgs) > 1, "At least 2 lock types required");
typedef tuple<_MArgs&...> _MutexTuple;
public:
_LIBCPP_INLINE_VISIBILITY
explicit scoped_lock(_MArgs&... __margs)
: __t_(__margs...)
{
_VSTD::lock(__margs...);
}
_LIBCPP_INLINE_VISIBILITY
scoped_lock(adopt_lock_t, _MArgs&... __margs)
: __t_(__margs...)
{
}
_LIBCPP_INLINE_VISIBILITY
~scoped_lock() {
typedef typename __make_tuple_indices<sizeof...(_MArgs)>::type _Indices;
__unlock_unpack(_Indices{}, __t_);
}
scoped_lock(scoped_lock const&) = delete;
scoped_lock& operator=(scoped_lock const&) = delete;
private:
template <size_t ..._Indx>
_LIBCPP_INLINE_VISIBILITY
static void __unlock_unpack(__tuple_indices<_Indx...>, _MutexTuple& __mt) {
_VSTD::__unlock(_VSTD::get<_Indx>(__mt)...);
}
_MutexTuple __t_;
};
#endif // _LIBCPP_STD_VER > 14
#endif // !_LIBCPP_HAS_NO_THREADS
struct _LIBCPP_TEMPLATE_VIS once_flag;
#ifndef _LIBCPP_CXX03_LANG
template<class _Callable, class... _Args>
_LIBCPP_INLINE_VISIBILITY
void call_once(once_flag&, _Callable&&, _Args&&...);
#else // _LIBCPP_CXX03_LANG
template<class _Callable>
_LIBCPP_INLINE_VISIBILITY
void call_once(once_flag&, _Callable&);
template<class _Callable>
_LIBCPP_INLINE_VISIBILITY
void call_once(once_flag&, const _Callable&);
#endif // _LIBCPP_CXX03_LANG
struct _LIBCPP_TEMPLATE_VIS once_flag
{
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR
once_flag() _NOEXCEPT : __state_(0) {}
#if defined(_LIBCPP_ABI_MICROSOFT)
typedef uintptr_t _State_type;
#else
typedef unsigned long _State_type;
#endif
private:
once_flag(const once_flag&); // = delete;
once_flag& operator=(const once_flag&); // = delete;
_State_type __state_;
#ifndef _LIBCPP_CXX03_LANG
template<class _Callable, class... _Args>
friend
void call_once(once_flag&, _Callable&&, _Args&&...);
#else // _LIBCPP_CXX03_LANG
template<class _Callable>
friend
void call_once(once_flag&, _Callable&);
template<class _Callable>
friend
void call_once(once_flag&, const _Callable&);
#endif // _LIBCPP_CXX03_LANG
};
#ifndef _LIBCPP_CXX03_LANG
template <class _Fp>
class __call_once_param
{
_Fp& __f_;
public:
_LIBCPP_INLINE_VISIBILITY
explicit __call_once_param(_Fp& __f) : __f_(__f) {}
_LIBCPP_INLINE_VISIBILITY
void operator()()
{
typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 1>::type _Index;
__execute(_Index());
}
private:
template <size_t ..._Indices>
_LIBCPP_INLINE_VISIBILITY
void __execute(__tuple_indices<_Indices...>)
{
__invoke(_VSTD::get<0>(_VSTD::move(__f_)), _VSTD::get<_Indices>(_VSTD::move(__f_))...);
}
};
#else
template <class _Fp>
class __call_once_param
{
_Fp& __f_;
public:
_LIBCPP_INLINE_VISIBILITY
explicit __call_once_param(_Fp& __f) : __f_(__f) {}
_LIBCPP_INLINE_VISIBILITY
void operator()()
{
__f_();
}
};
#endif
template <class _Fp>
void
__call_once_proxy(void* __vp)
{
__call_once_param<_Fp>* __p = static_cast<__call_once_param<_Fp>*>(__vp);
(*__p)();
}
_LIBCPP_FUNC_VIS void __call_once(volatile once_flag::_State_type&, void*,
void (*)(void*));
#ifndef _LIBCPP_CXX03_LANG
template<class _Callable, class... _Args>
inline _LIBCPP_INLINE_VISIBILITY
void
call_once(once_flag& __flag, _Callable&& __func, _Args&&... __args)
{
if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
{
typedef tuple<_Callable&&, _Args&&...> _Gp;
_Gp __f(_VSTD::forward<_Callable>(__func), _VSTD::forward<_Args>(__args)...);
__call_once_param<_Gp> __p(__f);
__call_once(__flag.__state_, &__p, &__call_once_proxy<_Gp>);
}
}
#else // _LIBCPP_CXX03_LANG
template<class _Callable>
inline _LIBCPP_INLINE_VISIBILITY
void
call_once(once_flag& __flag, _Callable& __func)
{
if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
{
__call_once_param<_Callable> __p(__func);
__call_once(__flag.__state_, &__p, &__call_once_proxy<_Callable>);
}
}
template<class _Callable>
inline _LIBCPP_INLINE_VISIBILITY
void
call_once(once_flag& __flag, const _Callable& __func)
{
if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
{
__call_once_param<const _Callable> __p(__func);
__call_once(__flag.__state_, &__p, &__call_once_proxy<const _Callable>);
}
}
#endif // _LIBCPP_CXX03_LANG
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP_MUTEX