X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=common%2Ffuture.h;h=65bea20b56b42e347a2fe89a841fa2b7d4adb5f1;hb=cc2e93138f0dd58a750b974c3cb7f548d1b26661;hp=17ff97782e0e5b9fffd0e8f75a10f7d02a528340;hpb=44dede2da63c289838cab72f9f19f831bc2e8d1d;p=casparcg

diff --git a/common/future.h b/common/future.h
index 17ff97782..65bea20b5 100644
--- a/common/future.h
+++ b/common/future.h
@@ -1,187 +1,57 @@
-#pragma once
-
-#include "enum_class.h"
-
-#include <boost/thread/future.hpp>
-#include <boost/thread/thread.hpp>
-#include <boost/shared_ptr.hpp>
-
-#include <functional>
-
-namespace caspar {
-	
-struct launch_policy_def
-{
-	enum type
-	{
-		async = 1,
-		deferred = 2
-	};
-};
-typedef caspar::enum_class<launch_policy_def> launch;
-
-namespace detail {
-	
-template<typename R>
-struct future_object_helper
-{	
-	template<typename T, typename F>
-	static void nonlocking_invoke(T& future_object, F& f)
-	{				
-        try
-        {
-			future_object.mark_finished_with_result_internal(f());
-        }
-        catch(...)
-        {
-			future_object.mark_exceptional_finish_internal(boost::current_exception());
-        }
-	}
-
-	template<typename T, typename F>
-	static void locking_invoke(T& future_object, F& f)
-	{				
-        try
-        {
-			future_object.mark_finished_with_result(f());
-        }
-        catch(...)
-        {
-			future_object.mark_exceptional_finish();
-        }
-	}
-};
-
-template<>
-struct future_object_helper<void>
-{	
-	template<typename T, typename F>
-	static void nonlocking_invoke(T& future_object, F& f)
-	{				
-        try
-        {
-			f();
-			future_object.mark_finished_with_result_internal();
-        }
-        catch(...)
-        {
-			future_object.mark_exceptional_finish_internal(boost::current_exception());
-        }
-	}
-
-	template<typename T, typename F>
-	static void locking_invoke(T& future_object, F& f)
-	{				
-        try
-        {
-			f();
-			future_object.mark_finished_with_result();
-        }
-        catch(...)
-        {
-			future_object.mark_exceptional_finish();
-        }
-	}
-};
-
-template<typename R, typename F>
-struct deferred_future_object : public boost::detail::future_object<R>
-{	
-	F f;
-	bool done;
-
-	template<typename F2>
-	deferred_future_object(F2&& f)
-		: f(std::forward<F2>(f))
-		, done(false)
-	{
-		set_wait_callback(std::mem_fn(&detail::deferred_future_object<R, F>::operator()), this);
-	}
-		
-	void operator()()
-	{		
-		boost::lock_guard<boost::mutex> lock2(mutex);
-
-		if(done)
-			return;
-
-		future_object_helper<R>::nonlocking_invoke(*this, f);
-
-		done = true;
-	}
-};
-
-template<typename R, typename F>
-struct async_future_object : public boost::detail::future_object<R>
-{	
-	F f;
-	boost::thread thread;
-
-	template<typename F2>
-	async_future_object(F2&& f)
-		: f(std::forward<F2>(f))
-		, thread([this]{run();})
-	{
-	}
-
-	~async_future_object()
-	{
-		thread.join();
-	}
-
-	void run()
-	{
-		future_object_helper<R>::locking_invoke(*this, f);
-	}
-};
-
-}
-	
-template<typename F>
-auto async(launch policy, F&& f) -> boost::unique_future<decltype(f())>
-{		
-	typedef decltype(f())								result_type;	
-	typedef boost::detail::future_object<result_type>	future_object_type;
-
-	boost::shared_ptr<future_object_type> future_object;
-
-	// HACK: This solution is a hack to avoid modifying boost code.
-
-	if((policy & launch::async) != 0)
-		future_object = boost::static_pointer_cast<future_object_type>(boost::make_shared<detail::async_future_object<result_type, F>>(std::forward<F>(f)));
-	else if((policy & launch::deferred) != 0)
-		future_object = boost::static_pointer_cast<future_object_type>(boost::make_shared<detail::deferred_future_object<result_type, F>>(std::forward<F>(f)));	
-	else
-		throw std::invalid_argument("policy");
-	
-	boost::unique_future<result_type> future;
-
-	static_assert(sizeof(future) == sizeof(future_object), "");
-
-	reinterpret_cast<boost::shared_ptr<future_object_type>&>(future) = std::move(future_object); // Get around the "private" encapsulation.
-	return std::move(future);
-}
-	
-template<typename F>
-auto async(F&& f) -> boost::unique_future<decltype(f())>
-{	
-	return async(launch::async | launch::deferred, std::forward<F>(f));
-}
-
-template<typename T>
-auto make_shared(boost::unique_future<T>&& f) -> boost::shared_future<T>
-{	
-	return boost::shared_future<T>(std::move(f));
-}
-
-template<typename T>
-auto flatten(boost::unique_future<T>&& f) -> boost::unique_future<decltype(f.get().get())>
-{
-	auto shared_f = make_shared(std::move(f));
-	return async(launch::deferred, [=]() mutable
-	{
-		return shared_f.get().get();
-	});
-}
-
+#pragma once
+
+#include <boost/thread/mutex.hpp>
+#include <boost/function.hpp>
+#include <boost/optional.hpp>
+
+#include <functional>
+#include <future>
+
+namespace caspar {
+
+template<typename T>
+auto flatten(std::future<T>&& f) -> std::future<typename std::decay<decltype(f.get().get())>::type>
+{
+	auto shared_f = f.share();
+	return std::async(std::launch::deferred, [=]() mutable -> typename std::decay<decltype(f.get().get())>::type
+	{
+		return shared_f.get().get();
+	});
+}
+
+template<typename F>
+bool is_ready(const F& future)
+{
+	return future.wait_for(std::chrono::seconds(0)) == std::future_status::ready;
+}
+
+/**
+ * Wrap a value in a future with an already known result.
+ * <p>
+ * Useful when the result of an operation is already known at the time of
+ * calling.
+ *
+ * @param value The r-value to wrap.
+ *
+ * @return The future with the result set.
+ */
+template<class R>
+std::future<R> make_ready_future(R&& value)
+{
+	std::promise<R> p;
+
+	p.set_value(value);
+
+	return p.get_future();
+}
+
+static std::future<void> make_ready_future()
+{
+	std::promise<void> p;
+
+	p.set_value();
+
+	return p.get_future();
+}
+
 }
\ No newline at end of file