Abstract: A network scheduler for real time applications is described. The network scheduler supports scheduling of network packets in a multi-threaded operating system to insure correct scheduling order and to preclude kernel preemption of active threads. The network scheduler resides between a kernel (and device drivers) and multiple sessions at the user-level. The network scheduler uses input/output control primitives such as HOLD and RELEASE to control servicing of the queues of packets at the kernel or network device driver. The control primitives serve as a middleware interface to the underlying kernel or network device driver. The network scheduler functions as a proxy scheduler to manage the queues of packets at the kernel or network device driver.

Abstract: A distributed block-based programming model for control applications such as multimedia based real-time applications is described. According to one aspect of the invention, user program specifies interconnections between a plurality of program blocks distributed across a plurality of processing nodes. The user program is automatically translated into a system-level program having a program fragment for each one of the processing nodes. Each one of the program fragments comprise the program blocks located on the processing node and one or more system-level blocks for establishing connections between the processing node and a different processing node across a network.