39 lines
1.1 KiB
C++
39 lines
1.1 KiB
C++
#pragma once
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namespace boost {
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template<typename T> class atomic;
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}
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namespace fc {
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class microseconds;
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class time_point;
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/**
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* @class spin_yield_lock
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* @brief modified spin-lock that yields on failure, but becomes a 'spin lock'
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* if there are no other tasks to yield to.
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*
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* This kind of lock is lighter weight than a full mutex, but potentially slower
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* than a staight spin_lock.
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*
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* This spin_yield_lock does not block the current thread, but instead attempts to use
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* an atomic operation to aquire the lock. If unsuccessful, then it yields to
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* other tasks before trying again. If there are no other tasks then yield is
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* a no-op and spin_yield_lock becomes a spin-lock.
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*/
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class spin_yield_lock {
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public:
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spin_yield_lock();
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bool try_lock();
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bool try_lock_for( const microseconds& rel_time );
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bool try_lock_until( const time_point& abs_time );
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void lock();
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void unlock();
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private:
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enum lock_store {locked,unlocked};
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int _lock;
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};
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} // namespace fc
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