Security_1 AFS   1. Consider the login process in AFS. You are a user of the system and you are assigned a username “user1” and password “pwd123”. You are using the system to make changes to a file right before the assignment deadline and, in a rush, you try to login to the system using the password “pwd1234”. List in detail the steps (the login phase and the potential steps in the bind phase) that will occur when you enter this password till the point you are denied access to the system.

Real_time_and_Multimedia_1b TS-Linux   The context for this question is the same as the previous question. 1. Assume that you are playing a game (G) on a version of TS-Linux in which the scheduler strictly follows the born priority of all the processes in making its scheduling decisions. The game uses ONE-SHOT timer with an overshoot parameter of To. The timer event goes off at time 0. Assume the following: When the timer goes off, the kernel has just started a critical section of duration Tk. For taking the necessary gaming action for the timer event, the video game application (G) has a processing time of Tg and priority P1. In addition to Tg, the application will need to make a blocking call to a Window Manager process (W) has a processing time of Tw and priority P3. When the timer goes off, the scheduling queue is empty. The priorities are ordered as P1 > P2 > P3 > P4 > …. With P1 being the highest priority. There are no periodic timers in the system. Duration of the scheduling time and interrupt handing time are negligible. Note that the given image is simply for your reference, and that the time Th has nothing to do with the solution. Only use the variables given in the text in your solutions.   (b) In the middle of W’s execution, another application process (S) whose duration is Ts and priority P2 becomes runnable. Does this change your calculation in the previous part of the question?

Real_time_and_Multimedia_2b PTS   The context for this question is the same as the previous question. 2. Consider two PTS channels, Ch1 and Ch2. The developer has defined the maximum number of items in each channel to be 5 (with the highest timestamps). Consider two threads T1 and T2 executing concurrently.  Ch1 has 5 items with timestamps: 10, 20, 30, 40, 50. Ch2 has 4 items with timestamps: 2, 4, 6, 8.  The two threads execute the same following code:  = get(Ch1, “oldest”);  processed-item = process(item);  put(Ch2, processed-item, ts);    (b) What does the developer have to do to ensure persistence of data in a PTS system?

Potpourri_8 QuickSilver   8. (True/False with justification) Quicksilver provides a more complete recovery management compared to LRVM. 

Potpourri_6 QuickSilver   6.  The number of Transaction Managers (TMs) in Quicksilver (choose one of the following):  One per node in the distributed system  One per transaction tree created in the system  One per application running on Quicksilver  One for the entire distributed system 

Failures_and_Recovery_1b LRVM   The context for this question is the same as the previous question. 1. A service that uses the LRVM library is in the middle of an LRVM transaction. There is a power failure before the transaction completes.   (b) Upon crash recovery what will be the state of the data segment that was being modified within the transaction at the time of the power failure?

Several mobile apps and mobile versions of websites have implemented a dark mode alternative to the traditional light mode. This dark mode setting presents an inverted color contrast compared to the traditional mode. However, due to the colors and light characteristics associated with navigating in dark mode, users may experience certain biological responses that could influence their behavior. For instance, in a mobile app from a retailer like The Cheesecake Factory, which primarily sells products associated with indulgence, navigating in dark mode could lead to:

Failures_and_Recovery_3b RioVista   The context for this question is the same as the previous question. 3. Consider RioVista, which implements LRVM semantics on top of Rio file cache.   (b) Does the implementation use UNDO log or UNDO record? Why? What is the difference between the two?

Real_time_and_Multimedia_1a TS-Linux   1. Assume that you are playing a game (G) on a version of TS-Linux in which the scheduler strictly follows the born priority of all the processes in making its scheduling decisions. The game uses ONE-SHOT timer with an overshoot parameter of To. The timer event goes off at time 0. Assume the following: When the timer goes off, the kernel has just started a critical section of duration Tk. For taking the necessary gaming action for the timer event, the video game application (G) has a processing time of Tg and priority P1. In addition to Tg, the application will need to make a blocking call to a Window Manager process (W) has a processing time of Tw and priority P3. When the timer goes off, the scheduling queue is empty. The priorities are ordered as P1 > P2 > P3 > P4 > …. With P1 being the highest priority. There are no periodic timers in the system. Duration of the scheduling time and interrupt handing time are negligible. Note that the given image is simply for your reference, and that the time Th has nothing to do with the solution. Only use the variables given in the text in your solutions.   (a) What is the maximum latency from time 0 for G to complete the action in response to the timer interrupt? Show your work.

Failures_and_Recovery_3c RioVista   The context for this question is the same as the previous question. 3. Consider RioVista, which implements LRVM semantics on top of Rio file cache.   (c)  Compare the log truncation code of RioVista to that of Satya’s LRVM.