ThreadHelper Usage Notes

Introduction

ThreadHelper defines a std::thread which runs the do_work() function as well as methods to start and stop that thread. It is intended to help reduce code duplication for the common task of starting and stopping threads.

Instantiation

ThreadHelper's constructor takes a std::function<void(std::atomic<bool>&) do_work parameter. This corresponds to the function that should be run in the thread when it is started. The single parameter is used to indicate that the thread should conclude its work and exit when false. (i.e. threads are expected to have a while(running_flag) loop in their void do_work(std::atomic<bool>& running_flag) method.)

Starting the worker thread

ThreadHelper defines a start_working_thread method which should be called to start the working thread. This method takes a single argument which is the desired pthread name for the working thread. This name is limited to 15 characters, over-long names will result in the new thread sharing the name of the calling process. The set name will not be immediately available within the do_work method and should not be relied upon.

Stopping the worker thread

ThreadHelper defines a stop_working_thread method which will set the atomic boolean running flag to false, indicating that the worker thread should exit. It will then attempt to join the working thread. The contract with the do_work method is thus that when the running flag is set to false, the method should conclude its work in a timely fashion.

Other Notes

Users of ThreadHelper may call the thread_running() method to determine if start_working_thread has been called. Since the method run by ThreadHelper is in the caller's scope, the working method has access to all state variables in that scope. Beware that most STL container types are not intrinsically thread-safe, and care should be used when accessing shared data.