53 lines
1.2 KiB
C++
53 lines
1.2 KiB
C++
/*
|
|
* Copyright (c) 2006-2021, RT-Thread Development Team
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* Change Logs:
|
|
* Date Author Notes
|
|
* 2021-04-27 flybreak the first version.
|
|
*/
|
|
|
|
#include "mutex"
|
|
|
|
namespace std
|
|
{
|
|
// use a set of global and static objects
|
|
// a proxy function to pthread_once
|
|
|
|
function<void()> once_functor;
|
|
|
|
mutex& get_once_mutex()
|
|
{
|
|
static mutex once_mutex;
|
|
return once_mutex;
|
|
}
|
|
|
|
inline unique_lock<mutex>*& get_once_functor_lock_ptr()
|
|
{
|
|
static unique_lock<mutex>* once_functor_mutex_ptr = nullptr;
|
|
return once_functor_mutex_ptr;
|
|
}
|
|
|
|
void set_once_functor_lock_ptr(unique_lock<mutex>* m_ptr)
|
|
{
|
|
get_once_functor_lock_ptr() = m_ptr;
|
|
}
|
|
|
|
extern "C"
|
|
{
|
|
void once_proxy()
|
|
{
|
|
// need to first transfer the functor's ownership so as to call it
|
|
function<void()> once_call = std::move(once_functor);
|
|
|
|
// no need to hold the lock anymore
|
|
unique_lock<mutex>* lock_ptr = get_once_functor_lock_ptr();
|
|
get_once_functor_lock_ptr() = nullptr;
|
|
lock_ptr->unlock();
|
|
|
|
once_call();
|
|
}
|
|
}
|
|
}
|