Real time means that correctness of result depends on both functional correctness and time that the result is delivered
* Soft real time
:- Utility degrades with distance from deadline
* Hard real time
:- System fails if deadline window is missed
* Firm real time
:- Result has no utility outside deadline window, but system can withstand a few missed results
dynamic job shop scheduling is the scheduling of the machine it can processes different jobs at time. it switches from one job to another job. in real time process jobs are executed based on the time.
Soft real-time scheduling means that, while processor and other scheduling algorithms may be optimized to give preference to higher-priority processes, no absolute guarantee of performance can be made. The hard real-time computer is designed for specialized purposes, where even the smallest amount of latency can make the difference between life and death.
A scheduler is the heart of every RTOS. It provides the algorithms to select the task for execution. Three common scheduling algorithms are > Cooperative scheduling > Round-robin scheduling > Preemptive scheduling RTOS uses preemptive (priority based) scheduling. In some cases, real-time requirements can be met by using static scheduling.
Cooperative schedulingPreemptive scheduling Rate-monotonic schedulingRound-robin schedulingFixed priority pre-emptive scheduling, an implementation of preemptive time slicingFixed-Priority Scheduling with Deferred PreemptionFixed-Priority Non-preemptive SchedulingCritical section preemptive schedulingStatic time schedulingEarliest Deadline First approachStochastic digraphs with multi-threaded graph traversal
Ready time, starting deadline, completion deadline, processing time, resource requirements, priority, subtask structure.
time complexity for Assembly line scheduling is linear.i.e O(n)
There isn't a single "best" scheduling algorithm, as the effectiveness of a scheduling algorithm depends on the specific requirements and constraints of the system in question. Common algorithms include Round Robin, Shortest Job First, and Priority Scheduling, each with its strengths and weaknesses. For real-time systems, Rate Monotonic Scheduling may be preferred, while for batch processing, Shortest Job First could be more efficient. Ultimately, the best choice depends on factors such as system load, response time requirements, and resource availability.
In real-time scheduling, handling problems typically involves prioritizing tasks based on their urgency and deadlines, using algorithms like Rate Monotonic or Earliest Deadline First. When issues arise, such as missed deadlines or resource contention, adaptive techniques like dynamic scheduling or task migration can be employed to mitigate delays. Additionally, implementing monitoring systems can help detect problems early, allowing for proactive adjustments to maintain system responsiveness and reliability. Effective communication and synchronization among tasks are also crucial in managing real-time constraints.
Specified time scheduling is a method used in computing and real-time systems where tasks are scheduled to start and complete at predetermined times. This approach ensures that critical tasks meet their deadlines, often utilizing time constraints to manage execution order. It is commonly applied in environments where timing is crucial, such as embedded systems or multimedia applications, to maintain performance and reliability. By adhering to a fixed schedule, specified time scheduling helps prevent resource contention and ensures predictable system behavior.
Facilities Scheduling is used to schedule date and time slots for facilities in order to ensure that there are no scheduling conflict between any parties and to facilitate planning.
Bernhard Walke has written: 'Realzeitrechner-Modelle' -- subject(s): Real-time data processing, Production scheduling, Queuing theory
Scheduling is necessary because a computer can only handle one task at a time.