33 Concurrency support library [thread]

33.11 Safe reclamation [saferecl]

33.11.2 Read-copy update (RCU) [saferecl.rcu] Class rcu_domain [saferecl.rcu.domain] Non-member functions [saferecl.rcu.domain.func]

rcu_domain& rcu_default_domain() noexcept;
Returns: A reference to a static-duration object of type rcu_domain.
A reference to the same object is returned every time this function is called.
void rcu_synchronize(rcu_domain& dom = rcu_default_domain()) noexcept;
Effects: If the call to rcu_synchronize does not strongly happen before the lock opening an RCU protection region R on dom, blocks until the unlock closing R happens.
Synchronization: The unlock closing R strongly happens before the return from rcu_synchronize.
void rcu_barrier(rcu_domain& dom = rcu_default_domain()) noexcept;
Effects: May evaluate any scheduled evaluations in dom.
For any evaluation that happens before the call to rcu_barrier and that schedules an evaluation E in dom, blocks until E has been evaluated.
Synchronization: The evaluation of any such E strongly happens before the return from rcu_barrier.
[Note 1: 
A call to rcu_barrier does not imply a call to rcu_synchronize and vice versa.
— end note]
template<class T, class D = default_delete<T>> void rcu_retire(T* p, D d = D(), rcu_domain& dom = rcu_default_domain());
Mandates: is_move_constructible_v<D> is true and the expression d(p) is well-formed.
Preconditions: D meets the Cpp17MoveConstructible and Cpp17Destructible requirements.
Effects: May allocate memory.
It is unspecified whether the memory allocation is performed by invoking operator new.
Initializes an object d1 of type D from std​::​move(d).
Schedules the evaluation of d1(p) in the domain dom; the behavior is undefined if that evaluation exits via an exception.
May invoke scheduled evaluations in dom.
[Note 2: 
If rcu_retire exits via an exception, no evaluation is scheduled.
— end note]
Throws: bad_alloc or any exception thrown by the initialization of d1.
[Note 3: 
If scheduled evaluations acquire resources held across any invocation of rcu_retire on dom, deadlock can occur.
— end note]