.tutorial

git-svn-id: svn://ultimatepp.org/upp/trunk@11376 f0d560ea-af0d-0410-9eb7-867de7ffcac7

tutorial/CoreTutorial/Async.cpp

@@ -0,0 +1,48 @@
+#include "Tutorial.h"
+
+void AsyncTutorial()
+{
+	/// .`AsyncWork`
+	
+	/// `AsyncWork` is `CoWork` based tool that resembles std::future. `AsyncWork` instances
+	/// are created using `Async` function and represent a work that can be done in parallel
+	/// with current thread. `AsyncWork` supports returning values. A call to `AsyncWork::Get`
+	/// makes sure that a work routine was finished and returns the return value (if any):
+
+	auto a = Async([](int n) -> double {
+		double f = 1;
+		for(int i = 2; i <= n; i++)
+			f *= i;
+		return f;
+	}, 100);
+	
+	DUMP(a.Get());
+	
+	/// Exceptions thrown in Async work are propagated upon call to `Get`:
+	
+	auto b = Async([] { throw "error"; });
+	
+	try {
+		b.Get();
+	}
+	catch(...) {
+		LOG("Exception has been caught");
+	}
+	
+	/// `AsyncWork` instances can be canceled (and are canceled in destructor if Get is not
+	/// called on them):
+	
+	{
+		auto c = Async([] {
+			for(;;)
+				if(CoWork::IsCanceled()) {
+					LOG("Work was canceled");
+					break;
+				}
+		});
+		Sleep(100); // give it chance to start
+		// c destructor cancels the work (can be explicitly canceled by Cancel method too)
+	}
+	
+	///
+}