bd531b9e08
Adds more documentation, and guarantees that the Object in the managed thread stays around until the Thread<> destructor is called. This might happen if .start() returns before .stop() is called, e.g. when a run loop in Object() terminates prematurely.
64 lines
1.6 KiB
C++
64 lines
1.6 KiB
C++
#ifndef MBGL_UTIL_THREAD
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#define MBGL_UTIL_THREAD
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#include <future>
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#include <thread>
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namespace mbgl {
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namespace util {
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// Manages a thread with Object.
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// Upon creation of this object, it launches a thread, creates an object of type Object in that
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// thread, and then calls .start(); on that object. When the Thread<> object is destructed, the
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// Object's .stop() function is called, and the destructor waits for thread termination. The
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// Thread<> constructor blocks until the thread and the Object are fully created, so after the
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// object creation, it's safe to obtain the Object stored in this thread.
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template <class Object>
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class Thread {
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public:
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template <class... Args>
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Thread(Args&&... args);
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Thread(const Thread&) = delete;
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Thread(Thread&&) = delete;
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Thread& operator=(const Thread&) = delete;
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Thread& operator=(Thread&&) = delete;
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~Thread();
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inline Object* operator->() const { return &object; }
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inline operator Object*() const { return &object; }
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private:
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std::thread thread;
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std::promise<void> joinable;
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Object& object;
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};
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template <class Object>
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template <class... Args>
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Thread<Object>::Thread(Args&&... args)
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: object([&]() -> Object& {
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std::promise<Object&> promise;
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thread = std::thread([&] {
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Object context(::std::forward<Args>(args)...);
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promise.set_value(context);
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context.start();
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joinable.get_future().get();
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});
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return promise.get_future().get();
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}()) {
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}
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template <class Object>
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Thread<Object>::~Thread() {
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object.stop();
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joinable.set_value();
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thread.join();
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}
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}
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}
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#endif
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