Resource Allocation Graph (RAG)
The resource allocation graph (RAG) is a popular technique for computer system deadlock detection. The RAG is a visual representation of the processes holding the resources and their current state of allocation. The resources and processes are represented by the graph’s nodes, while their allocation relationships are shown by the graph’s edges. A cycle in the graph of the RAG method denotes the presence of a deadlock. When a cycle is discovered, at least one resource needed by another process in the cycle is being held by each process in the cycle, causing a deadlock. The RAG method is a crucial tool in contemporary operating systems due to its high efficiency and ability to spot deadlocks quickly.
Recovery from Deadlock in Operating System
In today’s world of computer systems and multitasking environments, deadlock is an undesirable situation that can bring operations to a grinding halt. When multiple processes compete for exclusive access to resources and end up in a circular waiting pattern, a deadlock occurs. To maintain the smooth functioning of an operating system, it is crucial to implement recovery mechanisms that can break these deadlocks and restore the system’s productivity.
“Recovery from Deadlock in Operating Systems” refers to the set of techniques and algorithms designed to detect, resolve, or mitigate deadlock situations. These methods ensure that the system can continue processing tasks efficiently without being trapped in an eternal standstill. Let’s take a closer look at some of the key strategies employed.
There is no mechanism implemented by the OS to avoid or prevent deadlocks. The system, therefore, assumes that a deadlock will undoubtedly occur. The OS periodically checks the system for any deadlocks in an effort to break them. The OS will use various recovery techniques to restore the system if it encounters any deadlocks.
When a Deadlock Detection Algorithm determines that a deadlock has occurred in the system, the system must recover from that deadlock.