1. Midterm review: closed book multiple choice chapters 1 to 9
Operating Systems
Operating Systems
Midterm review:
closed book
multiple choice
chapters 1 to 9

2. COP 5994 - Operating Systems
Chapter 1&2: The Basics
kernel mode or kernel space
user mode or user space
system call:
user mode program invokes kernel mode functionality
COP Operating Systems

3. Chapter 2: Operating System Architectures
monolithic
layered
micro-kernel
distributed
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4. COP 5994 - Operating Systems
Chapter 3: Process
end
begin
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5. Process Control Blocks
Execution context
Process Control Blocks
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6. COP 5994 - Operating Systems
Context Switch
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7. COP 5994 - Operating Systems
Interrupt Processing
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8. Chapter 4: Thread vs. Process
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9. Combining User- and Kernel-level Threads
m-to-n thread mapping:
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10. Chapter 5: Concurrent execution
System has more than one thread/process
either independent or in cooperation:
mostly independent
occasionally need to communicate or synchronize
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11. Mutual exclusion algorithm
General structure of process Pi (vs. Pj)
do {
entry protocol
critical section
exit protocol
remainder section
} while (true);
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12. COP 5994 - Operating Systems
Semaphore
Software construct to enforce mutual exclusion
Contains a protected variable:
accessed via wait and signal commands
P V
binary semaphore: 0 or one
counting semaphore
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13. COP 5994 - Operating Systems
Chapter 6: Monitor
Programming language construct
Contains data and procedures needed to access shared resource
resource accessible only within the monitor
Supports:
mutual exclusion
synchronization
Dijkstra, Brinch-Hansen, Hoare
COP Operating Systems

14. Chapter 7: Conditions for Deadlock
Mutual exclusion
resource accessed by only one process at a time
Hold-and-wait-for
process holds resource(s) while waiting for other resource(s)
No-preemption
system cannot remove resource from the process until the process has finished using the resource
Circular-wait
processes are in a “circular chain” where each process is waiting for resource(s) of next process in chain
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15. Chapter 8: Processor scheduling
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16. COP 5994 - Operating Systems
Scheduling Criteria
CPU utilization
keep the CPU as busy as possible
Throughput
# of processes that complete per time unit
Turnaround time
amount of time to execute a process
Waiting time
time a process has been waiting in the ready queue
Response time
time from request until first response is produced
COP Operating Systems

17. COP 5994 - Operating Systems
Chapter 9: Memory
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18. Evolution of memory organization
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19. COP 5994 - Operating Systems
Preparation:
Self review questions
Chapter exercises
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