RThread: Use spin locker to protected resources from tasks
RThread: Use spin locker to protected resources from tasks

taskENTER_CRITICAL() and taskEXIT_CRITICAL() will block interrupts.

We don't need interrupt-safe functions, thread-safe enough.

starofrainnight/ArduinoRabirdToolkit,starofrainnight/ArduinoRabirdToolkit,starofrainnight/ArduinoRabirdTookit