Fix perf issue where main event loop takes 100% of CPU (#132)

Fix perf issue where main event loop takes 100% of CPU

We have a 2 threads:
Thread #1 runs in a loop polling the response queue
Thread #2 runs in a loop decoding responses from the sqltoolsservice over stdout and posting them to the response queue

Since thread #1 doesn't sleep, it's takes 100% CPU. In addition, running python 2.7 on windows, #2 doesn’t preempt the CPU due to #1 taking all of the CPU cycles, so no response is processed.

Fix is simple – thread #1 needs to sleep so thread #2 can get scheduled and get it’s work done.

Author: pensivebrian

mssqlscripter/main.py

@@ -86,8 +86,9 @@ def main(args):
         scripting_request.execute()
 
         while not scripting_request.completed():
+            # The sleep prevents burning up the CPU and lets other threads get scheduled.
+            time.sleep(0.1)
             response = scripting_request.get_response()
-
             if response:
                 scriptercallbacks.handle_response(response, parameters.DisplayProgress)
 

sql-xplat-cli.pyproj

@@ -5,15 +5,13 @@
     <SchemaVersion>2.0</SchemaVersion>
     <ProjectGuid>{f4bb6290-43f3-4f35-b26e-067c5ef8e64b}</ProjectGuid>
     <ProjectHome />
-    <StartupFile>build.py</StartupFile>
+    <StartupFile>mssqlscripter\main.py</StartupFile>
     <SearchPath>.</SearchPath>
     <WorkingDirectory>.</WorkingDirectory>
     <OutputPath>.</OutputPath>
     <ProjectTypeGuids>{888888a0-9f3d-457c-b088-3a5042f75d52}</ProjectTypeGuids>
     <LaunchProvider>Standard Python launcher</LaunchProvider>
-    <InterpreterId>Global|PythonCore|2.7</InterpreterId>
-    <CommandLineArguments>
-    </CommandLineArguments>
+    <CommandLineArguments>-S localhost -d AdventureWorks2014</CommandLineArguments>
     <EnableNativeCodeDebugging>False</EnableNativeCodeDebugging>
     <IsWindowsApplication>False</IsWindowsApplication>
   </PropertyGroup>
@@ -26,6 +24,7 @@
     <Content Include=".gitignore" />
     <Content Include="appveyor.yml" />
     <Content Include="dev_requirements.txt" />
+    <Content Include="doc\README.md" />
     <Content Include="doc\architecture_guide.md" />
     <Content Include="doc\development_guide.md" />
     <Content Include="doc\pypi_release_steps.md" />
@@ -49,9 +48,7 @@
     <Content Include=".travis.yml" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="build.py">
-      <SubType>Code</SubType>
-    </Compile>
+    <Compile Include="build.py" />
     <Compile Include="dev_setup.py" />
     <Compile Include="mssqlscripter\argparser.py" />
     <Compile Include="mssqlscripter\jsonrpc\contracts\scriptingservice.py" />
@@ -89,9 +86,5 @@
     <Folder Include="mssqltoolsservice\" />
     <Folder Include="mssqltoolsservice\mssqltoolsservice\" />
   </ItemGroup>
-  <ItemGroup>
-    <InterpreterReference Include="Global|PythonCore|2.7" />
-    <InterpreterReference Include="Global|PythonCore|3.6" />
-  </ItemGroup>
   <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\Python Tools\Microsoft.PythonTools.targets" />
 </Project>

sql-xplat-cli.sln

@@ -18,6 +18,6 @@ Global
 		HideSolutionNode = FALSE
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
-		SolutionGuid = {1DD06426-BEB7-4299-B45E-04535B761301}
+		SolutionGuid = {1A0F24BB-2803-4A8C-9816-CB374FAAC673}
 	EndGlobalSection
 EndGlobal