>>>No. This is as it should be, because -lpthread does threads in *one* >>>kernel process, so it has to intercept blocking operations so it can >>>switch to another thread instead, or call select/poll/kevent if >>>needed, so not all threads hang if *one* executes a blocking >>>operation. >> >> How could I help the high CPU usage then? The device driver read >> routine always prematurely exits because IO_NDELAY is set (and >> there's nothing to read - so EWOULDBLOCK is returned). > >the real syscall symbols are available as _thread_sys_read and so on. >you'll also need to clear non-blocking with _thread_sys_fcntl. >
If I would now use _thread_sys_read and so on, then the main thread would block (as expected), but due to the implementation, control is not passed to other threads (because of blocking on _thread_sys_read()) as far as I understand. It looks like I am not able to do threading and blocking at the same time, that's where I am stuck. Jan Engelhardt -- | Software Engineer and Linux/Unix Network Administrator
