funmiles / picoasync Goto Github PK

A purely coroutine based multi-tasking system needs all tasks to be good citizen of the cooperative multi-tasking system, yielding the CPU to other tasks in a periodic manner, enabling long running compute intensive tasks to run while not stopping other tasks from operating.
A yield awaitable object is a clean way of achieving this goal. It can be awaited periodically in long running loops:

task<> do_some_long_computation(int iterationCount, auto &&operation, priority myPriority)
{
    for (int i = 0; i < iterationCount; ++i) {
         // Perform one iteration's work
         operation(i);
         // Yield the CPU, signaling the queueing system our priority (optional argument)
         co_await cpu::yield(myPriority); 
     }
}

An example of such use is for the SSD1306 code. Filling the OLED screen buffer to print text can take tens of thousands of cycles.
The routine performing this operation should be capable of yielding so that time-critical operations can take place.

If you have multiple compilations units using the library, you get "multiple definitions" linker errors because of the functions defined in the header files, namely events.h. I guess a solution could be to inline those as well.

Off topic:
Great project! I'm glad I ran into this. I was looking for precedence to programming RP2040 async style. I hope the library catches on and keeps getting developed and maintained.