مناقشة الواجب tma01 - 2009 - itc350

[الــــريــــم]

Question 4 : [25 marks]
Suppose that the following processes arrive for execution at the times
indicated. Each process will run the listed amount of time. In answering
the questions, use non-preemptive scheduling and base all decisions
on the information you have at the time the decision must be made.
Process Arrival Time Burst Time
P
1 0.0 8
P
2 0.4 4
P
3 1.0 1
1. What is the average turnaround time for these processes with the

FCFS scheduling algorithm

10.53 ((8-0) + (12-0.4) + (13-1)) /3

2. What is the average turnaround time for these processes with theSJF scheduling algorithm

9.53 ((8-0) + (13-0.4) + (9-1)) /3

3. The SJF algorithm is supposed to improve performance, but notice
that we chose to run process P1 at time 0 because we did not know
that two shorter processes would arrive soon. Compute what the
average turnaround time will be if the CPU is left idle for the first 1
unit and then SJF scheduling is used. Remember that processes P1
and P2 are waiting during this idle time, so their waiting time may
increase. This algorithm could be known as future-knowledge

scheduling

6.86 ((14-0) + (6-0.4) + (13-1)) /3

\

\

اجتهاد شخصي لسؤال الرابع كاملا

اتمنى التصحيح في حال الخطأ

دعواتكم

[بحار]

شُكرا الريم .. واتمنى الإستمرار .. قبل وقت التسليم

[ELHAMSHARI]

المشاركة الأصلية كتبت بواسطة الــــريــــم

Question 4 : [25 marks]
Suppose that the following processes arrive for execution at the times
indicated. Each process will run the listed amount of time. In answering
the questions, use non-preemptive scheduling and base all decisions
on the information you have at the time the decision must be made.
Process Arrival Time Burst Time
P
1 0.0 8
P
2 0.4 4
P
3 1.0 1
1. What is the average turnaround time for these processes with the

FCFS scheduling algorithm

10.53 ((8-0) + (12-0.4) + (13-1)) /3

2. What is the average turnaround time for these processes with theSJF scheduling algorithm

9.53 ((8-0) + (13-0.4) + (9-1)) /3

3. The SJF algorithm is supposed to improve performance, but notice
that we chose to run process P1 at time 0 because we did not know
that two shorter processes would arrive soon. Compute what the
average turnaround time will be if the CPU is left idle for the first 1
unit and then SJF scheduling is used. Remember that processes P1
and P2 are waiting during this idle time, so their waiting time may
increase. This algorithm could be known as future-knowledge

scheduling

6.86 ((14-0) + (6-0.4) + (13-1)) /3

\

\

اجتهاد شخصي لسؤال الرابع كاملا

اتمنى التصحيح في حال الخطأ

دعواتكم

الله عليكي يالريم وش هاذا الابداع والحلاوه ماشاءالله والله ريحتينا جدا في السؤال الرابع


وياليت يارب يوفقك يارب يارب يارب وتحليلنا السؤال التاني كلووووو لاني مالحليت فيه شي ابداااا


وشكرا وربنا يخليكي يارب ــــــــــــــــــ بالتوفيق يارب في المواد

[miss_ksa]

السلام عليكم

الريم تسلمين الله يعطيك العافيه النواتج صحيحه

لكن من وين جبتي الارقام ياريت توضحين وتشرحين اذا ماعليكي امر

لاني عملت مقارنه بالسؤال مع المثال الي بتشابتر خمسه ص 158

بس ماطلع معااي شئ

جربت ارقام وسويت اشياء وماانفع

فيديني الله يسعدك

دمتي

وبالتوفيق جميعا

[بحار]

باقي السؤالين الثاني والثالث يا أحباب ..



ممكن تساعدونا

[بحار]

مادة مهمّشة إلى الحد اللي يخليهم ما يثبتون موضوع الواجب حقّها

[انا داوي]

المشاركة الأصلية كتبت بواسطة بحار

مادة مهمّشة إلى الحد اللي يخليهم ما يثبتون موضوع الواجب حقّها

خخخخخخخخخخخخخخخخخخخ وربي صادق

يعين الله بكرا التسليم والله يستر

[بحار]

الثـالث .. مين يدق الصدر له ..

[CRazy 4 LOveR]

Question 3 : [25 marks]


1. What are the five major activities of an operating system in regard to process management? [6]



 The creation and deletion of both user and system processes.
 The suspension and resumption of processes.
 The provision of mechanisms for process synchronization.
 The provision of mechanisms for process communication.
 The provision of mechanisms for deadlock handling.

[ألآلق]

Question 1 : [25 marks]
فقره 5



5. How does the distinction between kernel mode and user mode function as a
rudimentary form of protection (security) system? [5



User mode and kernel mode
Mode bit provided by hardware
Provides ability to distinguish when system is running user code or kernel code
Some instructions designated as privileged, only executable in kernel mode
System call changes mode to kernel, return from call resets it to user

Timer to prevent infinite loop / process hogging resources
Set interrupt after specific period
Operating system decrements counter
When counter zero generate an interrupt
Set up before scheduling process to regain control or terminate program that exceeds allotted time




هذا والله أعلم

[ألآلق]

Question 2 : [25 marks]

فقره 2..


2. Explain why the following resource allocation graph has a cycle but no deadlock. [5]


_ If graph contains no cycles  no deadlock.
_ If graph contains a cycle 
_ if only one instance per resource type, then deadlock.
_ if several instances per resource type, possibility of deadlock



فقره 3


3. Discuss methods for handling deadlocks.[3]




 Ensure that the system will never enter a deadlock state.
 Allow the system to enter a deadlock state and then recover.
 Ignore the problem and pretend that deadlocks never occur in the system; used by most operating systems, including UNIX.

إجتهاد شخصي
يعني مب كثير متأكده

اتمنى اكون أفدت بحااجه
هالماده تعل القلب

[romio]

يعطيك الف الف عافية
ويحققلك ما تتمني يا رب
تسلمي على الحل

[عاشق الرومانسيه]

يعطيكي الف الف الف الف الف الف الف الف الف الفالف الف الف الف الفالف الف الف الف الفالف الف الف الف الفالف الف الف الف الفالف الف الف الف الف يسلموووووووو ريحتينا الله يرحك دنيا وآاخره يارب >>> انت هتشحت

شكرا لمجهودك والله سويتي فينا خير ويارب يوفقك يارب

تحياتي

[ألآلق]

Question 3 : [25 marks

فقره 3..


3. When a process creates a new process using the fork() operation, which of the following state is shared between the parent process and the child process?[6]
Stack
Heap
Shared memory segments





أظن ..أظن ..( Shared memory segments )...