Assignment No. 03 Semester: Fall 2014 CS604 –Operating System Total Marks: 15 Due Date: 16/2/2015

[+ Aqib]

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Assignment
Question 1:   (5 Marks)   Consider the following snapshot of a system:     Allocation Max Available   A B C D A B C D A B C D P0 1 1 1 2 3 4 2 2 1 2 3 4 P1 1 0 2 2 1 3 4 14         P2 1 4 5 6 2 7 5 8         P3 2 5 4 2 3 5 7 9         P4 1 5 2 7 1 6 3 9           Need A B C D                                           Answer the following questions using the banker’s algorithm:   (a)   What is the content of the matrix Need?                                             5     (b)   Is the system in a safe state? If yes identify the safe sequence. Show the step by step execution by updating the data structure if necessary.                                                            10     NOTE:Do not put any query on MDB about this assignment, if you have any query then [e-mail].
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[Zakki]

this assignment is starving due to bad algorithm.

starvation problem

all students are here in deadlock, & busy waiting state.

[Prince]

@Zakki

So, here we should use Banker's algorithm to break the dead lock.

So start allocating the resources now.

Mera matlab he koi to discussion shuru kro na yar.

[MCS 4th Semester]

my safe sequence answer is : <P4,P0,P1,P2,P3>

is this correct?

[sawera]

a)      Content of the matrix Nedd:

 

Need
A	B	C	D
2	3	1	0
0	3	2	12
1	3	0	2
1	0	3	7
0	1	1	2

 

[sawera]

any one tel me how we find safe sequence muje to samaj nahi a rahi he just thora sa hint hi de den please

[sawera]

With the banker's algorithm you know the total number of resources available, and the maximum number of resources that each process may request. Being conservative, you're a banker after all, you assume that any process will request its maximum resources before finishing.

[+ Aqib]

correct !

[Alisha]

P4--P0--P1--P2--P3  ...is it correct ?

[Efficient48]

This is not correct Sequence..........

Correct sequence is  P4,P0,P2,P3,P1

[Zakki]

still dead lock!

---------------------

the longest deadlock in the history.

[Efficient48]

	Allocation				Max				Available
	A	B	C	D	A	B	C	D	A	B	C	D
P0	1	1	1	2	3	4	2	2	1	2	3	4
P1	1	0	2	2	1	3	4	14	2	7	5	11
P2	1	4	5	6	2	7	5	8	3	8	6	13
P3	2	5	4	2	3	5	7	9	4	12	10	18
P4	1	5	2	7	1	6	3	9	6	17	14	20

Safe Sequence is……….<P4,P0,P2,P3,P1>

[Zakki]

?

where is complete sol?