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No more use for retry_task in decklink_consumer now since audio and video are complet...
[casparcg] / common / future.h
index 7789ab871a6f388e1cd889b96ee25ff00b9ce3cf..65bea20b56b42e347a2fe89a841fa2b7d4adb5f1 100644 (file)
 #pragma once
 
-#include "enum_class.h"
-
-#include <boost/thread/future.hpp>
-#include <boost/thread/thread.hpp>
-#include <boost/shared_ptr.hpp>
+#include <boost/thread/mutex.hpp>
+#include <boost/function.hpp>
+#include <boost/optional.hpp>
 
 #include <functional>
+#include <future>
 
 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);
-       }
-
-       ~deferred_future_object()
-       {
-       }
-               
-       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()
+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
        {
-               future_object_helper<R>::locking_invoke(*this, f);
-       }
-};
-
+               return shared_f.get().get();
+       });
 }
-       
-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.reset(new detail::async_future_object<result_type, F>(std::forward<F>(f)), [](future_object_type* p){delete reinterpret_cast<detail::async_future_object<result_type, F>*>(p);});
-       else if((policy & launch::deferred) != 0)
-               future_object.reset(new detail::deferred_future_object<result_type, F>(std::forward<F>(f)), [](future_object_type* p){delete reinterpret_cast<detail::deferred_future_object<result_type, F>*>(p);});
-       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));
+bool is_ready(const F& future)
+{
+       return future.wait_for(std::chrono::seconds(0)) == std::future_status::ready;
 }
 
-template<typename T>
-auto make_shared(boost::unique_future<T>&& f) -> boost::shared_future<T>
-{      
-       return boost::shared_future<T>(std::move(f));
+/**
+ * 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();
 }
 
-template<typename T>
-auto flatten(boost::unique_future<T>&& f) -> boost::unique_future<decltype(f.get().get())>
+static std::future<void> make_ready_future()
 {
-       auto shared_f = make_shared(std::move(f));
-       return async(launch::deferred, [=]() mutable
-       {
-               return shared_f.get().get();
-       });
+       std::promise<void> p;
+
+       p.set_value();
+
+       return p.get_future();
 }
 
 }
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