13_Concurrency.md

13. Concurrency

13.2 Tasks and threads

• thread takes a function as its first argument
• join to wait until the thread is done
• Threads share an address space, which also allows communicating between them

13.3 Passing Arguments

• The remaining thread arguments are passed to the function
• Alternative: Store them in a function object

13.4 Returning Results

• Use pointers and references

13.5 Sharing Data

• mutex and unique_lock as discussed before

13.6 Waiting for Events

• <condition_variable> to notify other threads that a value is now available

13.7 Communicating Tasks

• promise to pass values, future to accept them
• value or exception is passed to promise
• future waits for them
• packaged_task creates promise and future
• async to run a function in a different thread, without knowing how many threads are created. It essentially works on a higher abstraction level. A call to async returns a promise