add mutex timeout limit; use atomic as refcount.

lichao

2021-04-22 1d6c040dcb9a01648edc66d8c0006c8c9294a705

 .vscode/launch.json

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