I'm rewriting existing real-time kernel TNKernel; I have used it for a couple of years, but I don't like many of its design decisions (as well as implementation details), so I decided to fork it and have fun implementing what I want. Anyone who is interested might read additional information at the project page on bitbucket.
TNKernel has one strange, in my opinion, feature: it has service tn_task_sleep(int timeout) which puts current task to sleep, and it has tn_task_wakeup(struct TN_Task *task) which wakes currently sleeping task up.
The strangeness is that it is legal to call tn_task_wakeup() on non-sleeping task; in this case, special flag like wakeup_request will be set, and on the next call to tn_task_sleep() this flag will be cleared, and task won't sleep.
All of this seems to me as a completely dirty hack, it probably might be used as a workaround to avoid race condition problems, or as a hacky replacement for semaphore.
It just encourages programmer to go with hacky approach, instead of creating straightforward semaphore and provide proper synchronization. So, I'm willing to remove this service from my project. Is this good idea to get rid of it, or have I missed something important? Why do we ever need that?
Since no one said that I'm wrong, I assumed that I'm right and removed these strange "features" from my kernel.