I used roughly the same philosophy recently at work in dealing with a library that could block for intolerable periods of time (sometimes indefinitely). Basical

I used roughly the same philosophy recently at work in dealing with a library that could block for intolerable periods of time (sometimes indefinitely). Basically, I used a pthread_mutex_trylock and a pthread_cond_signal to pass data to a worker thread that interacted with the library. If the worker thread was still holding the mutex when main thread wanted to send data to the worker thread, I simply say "f*ck it" and generate an error, rather than queueing up requests or locking up the system. The reason why it was okay to do this is that the library calls were to gather non-critical metrics, and calls into the library were fairly infrequent. (I just drank an entire bottle of wine, so please excuse any apparent lack of reasoning, typing ability, or general coherence in the above comment.)