add sleeper, to reduce cpu usage.

lichao

2021-05-20 6b96ee857e366af317ab9dc1b6b4f9c22576e83b

 .vscode/launch.json

@@ -14,7 +14,7 @@
                "ApiTest"
            ],
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}",
            "cwd": "${workspaceFolder}/debug",
            "environment": [],
            "externalConsole": false,
            "MIMode": "gdb",