Dear all, I have a question regarding two processes trying to read from same driver. Context: Suppose the driver maintains a circular buffer and when the head and tail are same any read request will be blocked. When driver has data, it asynchronously puts the data in the buffer. In the read system call then calls wake_up_interruptible() copying the data in user space buffer. Question: If two processes are sleeping on the read() system call for a driver and when driver has data will both of the processes will get the data or will there be a race condition? Is it like, the process which wakes up earlier, reads the data and as a result head and tail become same again. By the time the next process comes, it again finds there is nothing to read. If this is the case, then what is the way to share the data? One way I can think of if having a user space library and all read/writes should be done only through that library. Thanks in advance. --Himanshu -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
