Fast Component Interaction for Real-Time Systems

Open real-time systems provide for co-hosting hard-, soft- and non-real-time applications. Microkernel-based designs in addition allow for these applications to be mutually protected. Thus, trusted servers can coexist next to untrusted applications. These systems place a heavy burden on the performance of the message-passing mechanism, especially when based on microkernel-like inter-process communication. In this paper we introduce capacity-reserve donation (in short Credo), a mechanism for the fast interaction of interdependent components, which is applicable to common real-time resource-access models. We implemented Credo by extending L4’s message-passing mechanism to provide proper resource accounting and time-donation control, thereby preserving desired real-time properties. We were able to achieve priority inheritance and stackbased priority-ceiling resource sharing with virtually no overhead added to L4’s message-passing implementation. By providing a mechanism that does not...

• Type: Conference
• Year: 2005
• Where: ECRTS
• Authors: Udo Steinberg, Jean Wolter, Hermann Härtig
• Keywords: ECRTS 2005, L4’s Message-passing Mechanism, Message-passing Mechanism, Open Real-time Systems