Define Deadlock with Resource request and allocation graph (RRAG)

Deadlocks can be described through a directed bipartite graph termed as a RRAG that is Resource Request Allocation graph. A graph G = (V,E) is termed as bipartite if V can be decomposed in two disjoint sets V₁ and V₂ therefore every edge in E joins a vertex in V₁ to a vertex in V₂. Assume that V₁ be a set of processes and also V₂ be a set of resources. Thus the graph is directed we will seems as:

• An edge (R_j,P_i) that is an assignment edge to mean that resource R_j has been assigned to process P_i
• An edge (P_i,R_j) (termed as a request edge) to implies that process P_i has requested resource R_j