PPT Slide
Message-passing variations
- Call this new variation ReceiveMessageNoWait() and have a return value indicate there is no message on the queue. Problem now becomes one of much busy waiting as the receiver polls multiple queues in a loop (Figure 8.11 (b)).
- Can create children to handle each queue you want to receive on using traditional blocking (Figure 8.11 (a)).
- Can create a new system call that permits a process to block waiting for a SendMessage() on multiple queues (Figure 8.11 <c>). In most UNIXes, this is done via the select() system call (see “man -s 3c select” on xi).