Question

Suppose n processes, $P_1,....P_n$ share m identical resource units, which can be reserved and released one at a time. The maximum resource requirement of process $P_{i}is{s}_p$ where $s_i>0$. Which one of the following is a sufficient condition for ensuring that deadlock does not occur?

Answer 1

There are n processes $P_1,P_2,....P_n$.
Number of identical resources = m
The maximum resource requirements for process $P_{i}is{S}_p,where{S}_i>0$.
If all processes are in safe state then system can allocate resources to each process $P_i$ in some order and still avoid a deadlock. We can avoid the dead lock if each $P_i$ can still request can be satisfied by the current available resources plus the resources held by process $P_i$ such that j < i. The maximum resource requirement of n processes
is ${\sum }_{i=1}^n{s}_i$ and this amount must less than m + n.
$\therefore {\sum }_{i=1}^n{s}_i<(m+n)$