mirror of
https://github.com/matrix-construct/construct
synced 2024-07-04 01:38:24 +02:00
147 lines
2.9 KiB
C++
147 lines
2.9 KiB
C++
// Matrix Construct
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//
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// Copyright (C) Matrix Construct Developers, Authors & Contributors
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// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
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//
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// Permission to use, copy, modify, and/or distribute this software for any
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// purpose with or without fee is hereby granted, provided that the above
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// copyright notice and this permission notice is present in all copies. The
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// full license for this software is available in the LICENSE file.
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#pragma once
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#define HAVE_IRCD_CTX_SHARED_STATE_H
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namespace ircd::ctx
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{
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struct shared_state_base;
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template<class T = void> struct shared_state;
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template<> struct shared_state<void>;
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template<class T> struct promise;
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template<> struct promise<void>;
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template<class T> bool invalid(const shared_state<T> &);
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template<class T> bool pending(const shared_state<T> &);
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template<class T> bool retrieved(const shared_state<T> &);
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template<class T> bool ready(const shared_state<T> &);
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template<class T> void notify(shared_state<T> &);
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template<class T> void set_retrieved(shared_state<T> &);
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template<class T> void set_ready(shared_state<T> &);
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template<class T> void set_observed(shared_state<T> &);
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template<> void set_observed(shared_state<void> &);
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}
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struct ircd::ctx::shared_state_base
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{
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mutable dock cond;
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std::exception_ptr eptr;
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std::function<void (shared_state_base &)> then;
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};
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template<class T>
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struct ircd::ctx::shared_state
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:shared_state_base
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{
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using value_type = T;
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using pointer_type = T *;
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using reference_type = T &;
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promise<T> *p {nullptr};
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T val;
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shared_state(promise<T> &p)
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:p{&p}
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{}
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shared_state() = default;
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};
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template<>
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struct ircd::ctx::shared_state<void>
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:shared_state_base
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{
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using value_type = void;
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promise<void> *p {nullptr};
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shared_state(promise<void> &p)
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:p{&p}
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{}
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shared_state() = default;
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};
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template<class T>
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void
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ircd::ctx::notify(shared_state<T> &st)
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{
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st.cond.notify_all();
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if(!st.then)
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return;
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if(!current)
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return st.then(st);
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ircd::post([&st]
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{
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st.then(st);
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});
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}
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template<class T>
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void
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ircd::ctx::set_observed(shared_state<T> &st)
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{
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set_ready(st);
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}
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template<>
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inline void
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ircd::ctx::set_observed(shared_state<void> &st)
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{
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set_retrieved(st);
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}
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template<class T>
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void
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ircd::ctx::set_ready(shared_state<T> &st)
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{
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st.p = reinterpret_cast<promise<T> *>(uintptr_t(0x42));
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}
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template<class T>
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void
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ircd::ctx::set_retrieved(shared_state<T> &st)
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{
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st.p = reinterpret_cast<promise<T> *>(uintptr_t(0x84));
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}
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template<class T>
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bool
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ircd::ctx::ready(const shared_state<T> &st)
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{
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return st.p == reinterpret_cast<const promise<T> *>(uintptr_t(0x42));
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}
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template<class T>
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bool
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ircd::ctx::retrieved(const shared_state<T> &st)
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{
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return st.p == reinterpret_cast<const promise<T> *>(uintptr_t(0x84));
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}
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template<class T>
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bool
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ircd::ctx::pending(const shared_state<T> &st)
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{
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return st.p > reinterpret_cast<const promise<T> *>(uintptr_t(0x1000));
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}
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template<class T>
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bool
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ircd::ctx::invalid(const shared_state<T> &st)
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{
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return st.p == nullptr;
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}
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