512 lines
14 KiB
Plaintext
512 lines
14 KiB
Plaintext
#pragma once
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#if __cplusplus < 201103L
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#error "C++ version lower than C++11"
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#endif
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//#if defined(RT_USING_PTHREADS)
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#include <pthread.h>
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#include <system_error>
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#include <chrono>
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#include <utility>
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#include <functional>
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#include "__utils.h"
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#define rt_cpp_mutex_t pthread_mutex_t
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namespace std
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{
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// Base class on which to build std::mutex and std::timed_mutex
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class __mutex_base
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{
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protected:
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typedef rt_cpp_mutex_t __native_type;
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__native_type _m_mutex = PTHREAD_MUTEX_INITIALIZER;
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constexpr __mutex_base() noexcept = default;
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__mutex_base(const __mutex_base&) = delete;
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__mutex_base& operator=(const __mutex_base&) = delete;
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};
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class mutex : private __mutex_base
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{
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public:
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constexpr mutex() = default;
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~mutex() = default;
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mutex(const mutex&) = delete;
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mutex& operator=(const mutex&) = delete;
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void lock()
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{
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int err = pthread_mutex_lock(&_m_mutex);
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if (err)
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{
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throw_system_error(err, "mutex:lock failed.");
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}
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}
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bool try_lock() noexcept
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{
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return !pthread_mutex_trylock(&_m_mutex);
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}
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void unlock() noexcept
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{
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pthread_mutex_unlock(&_m_mutex);
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}
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typedef __native_type* native_handle_type;
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native_handle_type native_handle()
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{
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return &_m_mutex;
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};
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};
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inline int __rt_cpp_recursive_mutex_init(rt_cpp_mutex_t* m)
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{
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pthread_mutexattr_t attr;
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int res;
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res = pthread_mutexattr_init(&attr);
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if (res)
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return res;
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res = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
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if (res)
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goto attr_cleanup;
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res = pthread_mutex_init(m, &attr);
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attr_cleanup:
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int err = pthread_mutexattr_destroy(&attr);
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return res ? res : err;
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}
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class __recursive_mutex_base
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{
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protected:
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typedef rt_cpp_mutex_t __native_type;
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__native_type _m_recursive_mutex;
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__recursive_mutex_base(const __recursive_mutex_base&) = delete;
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__recursive_mutex_base& operator=(const __recursive_mutex_base&) = delete;
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__recursive_mutex_base()
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{
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int err = __rt_cpp_recursive_mutex_init(&_m_recursive_mutex);
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if (err)
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throw_system_error(err, "Recursive mutex failed to construct");
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}
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~__recursive_mutex_base()
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{
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pthread_mutex_destroy(&_m_recursive_mutex);
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}
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};
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class recursive_mutex : private __recursive_mutex_base
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{
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public:
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typedef __native_type* native_handle_type;
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recursive_mutex() = default;
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~recursive_mutex() = default;
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recursive_mutex(const recursive_mutex&) = delete;
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recursive_mutex& operator=(const recursive_mutex&) = delete;
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void lock()
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{
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int err = pthread_mutex_lock(&_m_recursive_mutex);
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if (err)
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throw_system_error(err, "recursive_mutex::lock failed");
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}
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bool try_lock() noexcept
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{
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return !pthread_mutex_trylock(&_m_recursive_mutex);
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}
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void unlock() noexcept
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{
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pthread_mutex_unlock(&_m_recursive_mutex);
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}
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native_handle_type native_handle()
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{ return &_m_recursive_mutex; }
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};
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#ifdef RT_PTHREAD_TIMED_MUTEX
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class timed_mutex;
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class recursive_timed_mutex;
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#endif // RT_PTHREAD_TIMED_MUTEX
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struct defer_lock_t {};
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struct try_to_lock_t {};
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struct adopt_lock_t {}; // take ownership of a locked mtuex
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constexpr defer_lock_t defer_lock { };
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constexpr try_to_lock_t try_to_lock { };
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constexpr adopt_lock_t adopt_lock { };
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template <class Mutex>
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class lock_guard
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{
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public:
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typedef Mutex mutex_type;
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explicit lock_guard(mutex_type& m) : pm(m) { pm.lock(); }
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lock_guard(mutex_type& m, adopt_lock_t) noexcept : pm(m)
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{ }
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~lock_guard()
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{ pm.unlock(); }
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lock_guard(lock_guard const&) = delete;
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lock_guard& operator=(lock_guard const&) = delete;
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private:
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mutex_type& pm;
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};
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template <class Mutex>
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class unique_lock
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{
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public:
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typedef Mutex mutex_type;
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unique_lock() noexcept : pm(nullptr), owns(false) { }
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explicit unique_lock(mutex_type& m)
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: pm(std::addressof(m)), owns(false)
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{
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lock();
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owns = true;
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}
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unique_lock(mutex_type& m, defer_lock_t) noexcept
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: pm(std::addressof(m)), owns(false)
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{ }
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unique_lock(mutex_type& m, try_to_lock_t) noexcept
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: pm(std::addressof(m)), owns(pm->try_lock())
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{ }
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unique_lock(mutex_type& m, adopt_lock_t) noexcept
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: pm(std::addressof(m)), owns(true)
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{ }
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// any lock-involving timed mutex API is currently only for custom implementations
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// the standard ones are not available
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template <class Clock, class Duration>
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unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time) noexcept
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: pm(std::addressof(m)), owns(pm->try_lock_until(abs_time))
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{ }
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template <class Rep, class Period>
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unique_lock(mutex_type& m, const chrono::duration<Rep, Period>& rel_time) noexcept
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: pm(std::addressof(m)), owns(pm->try_lock_for(rel_time))
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{ }
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~unique_lock()
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{
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if (owns)
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unlock();
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}
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unique_lock(unique_lock const&) = delete;
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unique_lock& operator=(unique_lock const&) = delete;
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unique_lock(unique_lock&& u) noexcept
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: pm(u.pm), owns(u.owns)
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{
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u.pm = nullptr;
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u.owns = false;
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}
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unique_lock& operator=(unique_lock&& u) noexcept
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{
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if (owns)
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unlock();
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unique_lock(std::move(u)).swap(*this);
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u.pm = nullptr;
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u.owns = false;
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return *this;
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}
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void lock()
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{
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if (!pm)
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throw_system_error(int(errc::operation_not_permitted),
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"unique_lock::lock: references null mutex");
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else if (owns)
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throw_system_error(int(errc::resource_deadlock_would_occur),
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"unique_lock::lock: already locked" );
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else {
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pm->lock();
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owns = true;
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}
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}
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bool try_lock()
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{
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if (!pm)
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throw_system_error(int(errc::operation_not_permitted),
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"unique_lock::try_lock: references null mutex");
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else if (owns)
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throw_system_error(int(errc::resource_deadlock_would_occur),
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"unique_lock::try_lock: already locked" );
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else {
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owns = pm->try_lock();
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}
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return owns;
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}
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template <class Rep, class Period>
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bool try_lock_for(const chrono::duration<Rep, Period>& rel_time)
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{
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if (!pm)
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throw_system_error(int(errc::operation_not_permitted),
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"unique_lock::try_lock_for: references null mutex");
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else if (owns)
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throw_system_error(int(errc::resource_deadlock_would_occur),
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"unique_lock::try_lock_for: already locked");
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else {
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owns = pm->try_lock_for(rel_time);
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}
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return owns;
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}
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template <class Clock, class Duration>
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bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time)
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{
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if (!pm)
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throw_system_error(int(errc::operation_not_permitted),
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"unique_lock::try_lock_until: references null mutex");
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else if (owns)
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throw_system_error(int(errc::resource_deadlock_would_occur),
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"unique_lock::try_lock_until: already locked");
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else {
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owns = pm->try_lock_until(abs_time);
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}
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return owns;
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}
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void unlock()
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{
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if (!owns)
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throw_system_error(int(errc::operation_not_permitted),
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"unique_lock::unlock: not locked");
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else {
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pm->unlock();
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owns = false;
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}
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}
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void swap(unique_lock& u) noexcept
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{
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std::swap(pm, u.pm);
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std::swap(owns, u.owns);
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}
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mutex_type *release() noexcept
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{
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mutex_type* ret_mutex = pm;
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pm = nullptr;
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owns = false;
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return ret_mutex;
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}
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bool owns_lock() const noexcept
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{ return owns; }
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explicit operator bool() const noexcept
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{ return owns_lock(); }
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mutex_type* mutex() const noexcept
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{ return pm; }
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private:
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mutex_type *pm;
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bool owns;
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};
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template <class Mutex>
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void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y)
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{
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x.swap(y);
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}
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template <class L0, class L1>
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int try_lock(L0& l0, L1& l1)
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{
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unique_lock<L0> u0(l0, try_to_lock); // try to lock the first Lockable
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// using unique_lock since we don't want to unlock l0 manually if l1 fails to lock
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if (u0.owns_lock())
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{
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if (l1.try_lock()) // lock the second one
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{
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u0.release(); // do not let RAII of a unique_lock unlock l0
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return -1;
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}
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else
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return 1;
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}
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return 0;
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}
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template <class L0, class L1, class L2, class... L3>
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int try_lock(L0& l0, L1& l1, L2& l2, L3&... l3)
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{
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int r = 0;
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unique_lock<L0> u0(l0, try_to_lock);
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// automatically unlock is done through RAII of unique_lock
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if (u0.owns_lock())
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{
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r = try_lock(l1, l2, l3...);
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if (r == -1)
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u0.release();
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else
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++r;
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}
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return r;
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}
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template <class L0, class L1, class L2, class ...L3>
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void
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__lock_first(int i, L0& l0, L1& l1, L2& l2, L3&... l3)
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{
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while (true)
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{
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// we first lock the one that is the most difficult to lock
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switch (i)
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{
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case 0:
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{
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unique_lock<L0> u0(l0);
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i = try_lock(l1, l2, l3...);
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if (i == -1)
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{
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u0.release();
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return;
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}
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}
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++i;
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sched_yield();
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break;
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case 1:
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{
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unique_lock<L1> u1(l1);
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i = try_lock(l2, l3..., l0);
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if (i == -1)
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{
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u1.release();
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return;
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}
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}
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if (i == sizeof...(L3) + 1) // all except l0 are locked
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i = 0;
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else
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i += 2; // since i was two-based above
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sched_yield();
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break;
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default:
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__lock_first(i - 2, l2, l3..., l0, l1);
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return;
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}
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}
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}
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template <class L0, class L1>
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void lock(L0& l0, L1& l1)
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{
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while (true)
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{
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{
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unique_lock<L0> u0(l0);
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if (l1.try_lock())
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{
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u0.release();
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break;
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}
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}
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sched_yield();
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// wait and try the other way
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{
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unique_lock<L1> u1(l1);
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if (l0.try_lock())
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{
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u1.release();
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break;
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}
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}
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sched_yield();
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}
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}
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template <class L0, class L1, class... L2>
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void lock(L0& l0, L1& l1, L2&... l2)
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{
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__lock_first(0, l0, l1, l2...);
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}
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struct once_flag
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{
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constexpr once_flag() noexcept = default;
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once_flag(const once_flag&) = delete;
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once_flag& operator=(const once_flag&) = delete;
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template <class Callable, class... Args>
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friend void call_once(once_flag& flag, Callable&& func, Args&&... args);
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private:
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pthread_once_t _m_once = PTHREAD_ONCE_INIT;
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};
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mutex& get_once_mutex();
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extern function<void()> once_functor;
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extern void set_once_functor_lock_ptr(unique_lock<mutex>*);
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extern "C" void once_proxy(); // passed into pthread_once
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template <class Callable, class... Args>
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void call_once(once_flag& flag, Callable&& func, Args&&... args)
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{
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// use a lock to ensure the call to the functor
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// is exclusive to only the first calling thread
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unique_lock<mutex> functor_lock(get_once_mutex());
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auto call_wrapper = std::bind(std::forward<Callable>(func), std::forward<Args>(args)...);
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once_functor = [&]() { call_wrapper(); };
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set_once_functor_lock_ptr(&functor_lock); // so as to unlock when actually calling
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int err = pthread_once(&flag._m_once, &once_proxy);
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if (functor_lock)
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set_once_functor_lock_ptr(nullptr);
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if (err)
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throw_system_error(err, "call_once failed");
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}
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}
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//#endif //(RT_USING_PTHREADS) |