A k-bounded priority queue transforms an input sequence CT into an output sequence z which is a re-ordering of the sequence c while never storing more than k elements during the transformation. We consider the set of all such related pairs (a, 7) in both the case that cs is a binary sequence and the case that o is a permutation of 1,2,. , n. We derive properties of this relation and use it to d...

Well-known results on the ergodicity of queues with preemptive priority were obtained under assumption that jobs arrive according to Poisson process. This assumption, however, does not always hold true in practice. In our work we find sufficient conditions for two classes a single server, where interarrival times high-priority have either Erlang or hyperexponential distribution and low-priority...

Background The inclusion of cost-effectiveness data, as a basis for priority setting rankings, is a distinguishing feature in the formulation of the Swedish national guidelines. Guidelines are generated with the direct intent to influence health policy and support decisions about the efficient allocation of scarce healthcare resources. Certain medical conditions may be given higher priority ran...

Structuring real-time concurrent programs in the form of groups of fixed-priority processes is an old art which is appropriate for only a small fraction of modern real-time distributed computing application systems. However, it is still practiced on the basis of an insufficient technical foundation. One of the basic issues in using the fixed-priority process structuring approach is to avoid the...

We investigate the use of priority mechanisms when assigning service engineers to customers as a tool for service differentiation. To this end, we analyze a non-preemptive M/G/c priority queue with various customer classes. For this queue, we present various accurate and fast methods to estimate the first two moments of the waiting time per class given that all servers are occupied. These waiti...

The contributions of this paper are threefold. First, a solution to the problem of prioritized mutual exclusion in a distributed system is proved correct. This protocol is based on fewer requirements than prioritized extensions of other protocols and outperforms other protocols with an average complexity of (log n) and a worst-case complexity of O(n) messages for n nodes. Second, the concept of...

Real-Time Mach provides real-time thread and real-time synchronization facilities. A real-time thread can be created for a periodic or aperiodic activity with a timing constraint. Threads can be synchronized among them using a real-time version of the monitor based synchronization mechanism with a suitable locking protocol. In Real-Time Mach, we have implemented several locking policies, such a...

In recent years, real-time operating systems began to support the resource reservation paradigm. This technique has proved to be very effective in providing QoS to both, real-time and legacy applications, ensuring that the temporal misbehavior of an application does not affect any other (temporal isolation). However, resource sharing in a reservation system is still not well understood, and can...

A limitation in the design of the interface of C++ standard priority queues is addressed. The use of priority queues in Dijkstra’s shortest path search algorithm is used as an example. Priority queues are often implemented using heaps. There is a problem, as it may be necessary to change the priority of an element while it is in the queue, but finding the element from within a heap is costly. T...

We investigate the use of priority mechanisms when assigning service engineers to customers as a tool for service differentiation. To this end, we analyze a nonpreemptive M/P H/c priority queue with various customer classes. For this queue, we present various accurate and fast methods to estimate the first two moments of the waiting time per class given that all servers are occupied. These wait...