forked from lix-project/hydra
54 lines
1 KiB
C++
54 lines
1 KiB
C++
#pragma once
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#include <mutex>
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#include <condition_variable>
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/* This template class ensures synchronized access to a value of type
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T. It is used as follows:
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struct Data { int x; ... };
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Sync<Data> data;
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{
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auto data_(data.lock());
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data_->x = 123;
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}
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Here, "data" is automatically unlocked when "data_" goes out of
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scope.
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*/
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template <class T>
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class Sync
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{
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private:
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std::mutex mutex;
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T data;
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public:
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class Lock
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{
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private:
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Sync * s;
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friend Sync;
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Lock(Sync * s) : s(s) { s->mutex.lock(); }
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public:
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Lock(Lock && l) : s(l.s) { l.s = 0; }
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Lock(const Lock & l) = delete;
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~Lock() { if (s) s->mutex.unlock(); }
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T * operator -> () { return &s->data; }
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T & operator * () { return s->data; }
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/* FIXME: performance impact of condition_variable_any? */
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void wait(std::condition_variable_any & cv)
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{
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assert(s);
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cv.wait(s->mutex);
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}
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};
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Lock lock() { return Lock(this); }
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};
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