* @brief Set timeout. When it expires, the coroutine will wake up * * @param ts The relative time duration, or the absolute time stamp.

* @brief Acquire a lock on the mutex. If the lock could not be acquired * synchronous then the awaiting coroutine will be suspended an later

Precondition: calling thread holds the lock.

One function that prints the system call and the error details and then exits with error code 1. Non-zero meaning things didn't go well. */