新增一个channel测试项目

.gitignore

@@ -5,3 +5,4 @@
 /vs_proj/x64
 /vs_proj/.vs
 /vs_proj/librf.vcxproj.user
+/.vs

benchmark/benchmark_channel_passing_next.cpp

@@ -0,0 +1,55 @@
+
+#include <chrono>
+#include <iostream>
+#include <string>
+#include <thread>
+#include <deque>
+#include <mutex>
+
+#include "librf.h"
+
+using namespace resumef;
+using namespace std::chrono;
+using namespace std::literals;
+
+const static auto MaxNum = 20000;
+using int_channel_ptr = std::shared_ptr<channel_t<intptr_t>>;
+
+static future_vt passing_next(int_channel_ptr rd, int_channel_ptr wr)
+{
+	for (;;)
+	{
+		intptr_t value = co_await *rd;
+		co_await (*wr << (value + 1));
+	}
+}
+
+void benchmark_main_channel_passing_next()
+{
+	int_channel_ptr head = std::make_shared<channel_t<intptr_t>>(1);
+	int_channel_ptr in = head;
+	int_channel_ptr tail = nullptr;
+
+	for (int i = 0; i < MaxNum; ++i)
+	{
+		tail = std::make_shared<channel_t<intptr_t>>(1);
+		go passing_next(in, tail);
+		in = tail;
+	}
+
+	GO
+	{
+		for (;;)
+		{
+			auto tstart = high_resolution_clock::now();
+
+			co_await (*head << 0);
+			intptr_t value = co_await *tail;
+
+			auto dt = duration_cast<duration<double>>(high_resolution_clock::now() - tstart).count();
+			std::cout << value << " cost time " << dt << "s" << std::endl;
+		}
+	};
+
+	this_scheduler()->run_until_notask();
+}

vs_proj/librf.vcxproj

@@ -182,6 +182,7 @@
   <ItemGroup>
     <ClCompile Include="..\benchmark\benchmark_asio_echo.cpp" />
     <ClCompile Include="..\benchmark\benchmark_async_mem.cpp" />
+    <ClCompile Include="..\benchmark\benchmark_channel_passing_next.cpp" />
     <ClCompile Include="..\librf\src\event.cpp" />
     <ClCompile Include="..\librf\src\mutex.cpp" />
     <ClCompile Include="..\librf\src\rf_task.cpp" />

vs_proj/librf.vcxproj.filters

@@ -106,6 +106,9 @@
     <ClCompile Include="..\tutorial\test_async_modern_cb.cpp">
       <Filter>tutorial</Filter>
     </ClCompile>
+    <ClCompile Include="..\benchmark\benchmark_channel_passing_next.cpp">
+      <Filter>benchmark</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\librf\librf.h">