___________________________________________________________________ NAME: (First name first)
COSC 4330/6310
FIRST PROBLEM SET
DUE JUNE 14 IN CLASS
1. Answer in a few words to each of the following questions:
(a) How does the memory management unit of a computer contributes to its security?
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(b) Give an example of a real-time process with soft deadlines?
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(c) Why do most operating systems on the market continue to use monolithic kernels?
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(d) What is the purpose of timer interrupts?
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(e) Would UNIX have had the same impact if its kernel had been written in assembly code?
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(f) Which event(s) will move a process from the running state to the waiting state?
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(g) Which processes are good candidates for being suspended when memory is tight?
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(h) What do parent and child processes share after a fork()?
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(i) What is the purpose of the signal() system call?
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2. How many lines will the following program print out?
main() {
fork();
printf("Hello!\n");
fork();
printf("Goodbye!\n");
} // main
Answer: _____ lines.
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COSC 4330/6310
FIRST PROBLEM 2012
3. SET
SPRING Advantages and disadvantages: Do not mention a disadvantage when an advantage is asked and vice versa!
(a) What is the main advantage of modular kernels?
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(b) What is the main disadvantage of the master/slave organization for multiprocessor operating systems?
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(c) What is the main advantage of dual-mode CPUs?
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(d) What is the main disadvantage of microkernels?
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(e) What is the main advantage of the symmetric organization for multiprocessor operating systems?
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(f) What is the main advantage of delayed writes?
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(g) What is the main disadvantage of modular kernels?
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(h) What is the main advantage of direct-memory access?
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4. How will the following code fragment affect stdin, stdout and stderr?
int fda, fdb;
fda = open("alpha", O_RDWR | O_CREAT, 0640);
fdb = open("beta" , O_RDWR | O_CREAT, 0640);
close (2);
dup(fda);
close(0);
dup(fdb);
stdin is ___________________________________________________________________________
stdout is ___________________________________________________________________________
stderr is ___________________________________________________________________________
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