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Diffstat (limited to 'src/mbgl/actor/actor.hpp')
-rw-r--r-- | src/mbgl/actor/actor.hpp | 77 |
1 files changed, 0 insertions, 77 deletions
diff --git a/src/mbgl/actor/actor.hpp b/src/mbgl/actor/actor.hpp deleted file mode 100644 index 810114c513..0000000000 --- a/src/mbgl/actor/actor.hpp +++ /dev/null @@ -1,77 +0,0 @@ -#pragma once - -#include <mbgl/actor/mailbox.hpp> -#include <mbgl/actor/message.hpp> -#include <mbgl/actor/actor_ref.hpp> -#include <mbgl/util/noncopyable.hpp> - -#include <memory> - -namespace mbgl { - -/* - An `Actor<O>` is an owning reference to an asynchronous object of type `O`: an "actor". - Communication with an actor happens via message passing: you send a message to the object - (using `invoke`), passing a pointer to the member function to call and arguments which - are then forwarded to the actor. - - The actor receives messages sent to it asynchronously, in a manner defined its `Scheduler`. - To store incoming messages before their receipt, each actor has a `Mailbox`, which acts as - a FIFO queue. Messages sent from actor S to actor R are guaranteed to be processed in the - order sent. However, relative order of messages sent by two *different* actors S1 and S2 - to R is *not* guaranteed (and can't be: S1 and S2 may be acting asynchronously with respect - to each other). - - An `Actor<O>` can be converted to an `ActorRef<O>`, a non-owning value object representing - a (weak) reference to the actor. Messages can be sent via the `Ref` as well. - - It's safe -- and encouraged -- to pass `Ref`s between actors via messages. This is how two-way - communication and other forms of collaboration between multiple actors is accomplished. - - It's safe for a `Ref` to outlive its `Actor` -- the reference is "weak", and does not extend - the lifetime of the owning Actor, and sending a message to a `Ref` whose `Actor` has died is - a no-op. (In the future, a dead-letters queue or log may be implemented.) - - Construction and destruction of an actor is currently synchronous: the corresponding `O` - object is constructed synchronously by the `Actor` constructor, and destructed synchronously - by the `~Actor` destructor, after ensuring that the `O` is not currently receiving an - asynchronous message. (Construction and destruction may change to be asynchronous in the - future.) The constructor of `O` is passed an `ActorRef<O>` referring to itself (which it - can use to self-send messages), followed by the forwarded arguments passed to `Actor<O>`. - - Please don't send messages that contain shared pointers or references. That subverts the - purpose of the actor model: prohibiting direct concurrent access to shared state. -*/ - -template <class Object> -class Actor : public util::noncopyable { -public: - template <class... Args> - Actor(Scheduler& scheduler, Args&&... args_) - : mailbox(std::make_shared<Mailbox>(scheduler)), - object(self(), std::forward<Args>(args_)...) { - } - - ~Actor() { - mailbox->close(); - } - - template <typename Fn, class... Args> - void invoke(Fn fn, Args&&... args) { - mailbox->push(actor::makeMessage(object, fn, std::forward<Args>(args)...)); - } - - ActorRef<std::decay_t<Object>> self() { - return ActorRef<std::decay_t<Object>>(object, mailbox); - } - - operator ActorRef<std::decay_t<Object>>() { - return self(); - } - -private: - std::shared_ptr<Mailbox> mailbox; - Object object; -}; - -} // namespace mbgl |