CSCE 3600 EXAM QUESTIONS AND ANSWERS
LATEST UPDATE (ALREADY GRADED A+)
Compaction
-Reduce external fragmentation
-Shuffle memory contents to place all free memory together in one large block
Best Fit
-Keep linked list of free blocks
-Search he whole list on each allocation
-Choose block that comes closest to matching the needs of allocation
-Save excess for later
-Merge adjacent free blocks during release operation
First Fit
-Keep linked list of free blocks
-Scan the list for the first block that comes closest to matching the needs of allocation
-Merge adjacent free blocks during release operation
Optimal Page Replacement
Replace the page that will not be reference for the longest time. Gives the lowest possible fault rate but
is impossible to implement.
First-In, First-Out (FIFO)
The oldest page in physical memory is the one selected for replacement. Poorest replacement policy
Worst Fit
-Keep linked list of free blocks
-Search the whole list on each allocation
-Choose block that worst matches the request
-Save excess for later
-Merge adjacent free blocks during release operation
Next Fit
-Keep linked list of free blocks
-Start where the last search left off
-Scan the list for the first block that comes closest to matching the needs of allocation
-Merge adjacent free blocks during release opertion
Overlays
, Programmer breaking code into pieces that fit into RAM. These pieces, called overlays, are loaded and
unloaded by the program
Page Table
Table that holds VA -> PA translations (Virtual address to physical address)
Thrashing
a process is busy swapping pages in and out. Causes : not having enough pages. Effects: Low CPU
utilization, operating system thinking that it needs to increase the degree of multiprogramming, or
adding another process to the system
A parser will NOT check to see that the input is semantically correct
Child processes canNOT change variables in its parent process
new processes are created by the fork() system call
exec() is..
a functionality of an operating system that runs an executable file in the context of an already existing
process, replacing the previous executable
Two UNIX/Linux processes may simultaneously have open file descriptors that...
refer to the same open file description
INET domain sockets can only send messages to...
a different machine
The UNIX/Linux OS does NOT allow multiple processes per thread
A function is said to be thread-safe if..
it can be called from multiple threads without unwanted interation between the threads
For a given mutex, if 1+ threads are blocked on a call to pthread_mutex_lock() and the thread that is
holding the lock calls pthread_mutex_unlock()..
exactly one of the unblocked threads will be unblocked and thus able to lock the mutex
pthread_exit is
a Pthead function that terminates the calling thread and makes the value (value_ptr) available to any
successful join with the terminting thread
When programming via threads, a ________ would give each thread it's own unique copy
stack
An application that allows two different machines to communicate using a socket requires..
one of the machines to implement a server sockets an the other a client socket
LATEST UPDATE (ALREADY GRADED A+)
Compaction
-Reduce external fragmentation
-Shuffle memory contents to place all free memory together in one large block
Best Fit
-Keep linked list of free blocks
-Search he whole list on each allocation
-Choose block that comes closest to matching the needs of allocation
-Save excess for later
-Merge adjacent free blocks during release operation
First Fit
-Keep linked list of free blocks
-Scan the list for the first block that comes closest to matching the needs of allocation
-Merge adjacent free blocks during release operation
Optimal Page Replacement
Replace the page that will not be reference for the longest time. Gives the lowest possible fault rate but
is impossible to implement.
First-In, First-Out (FIFO)
The oldest page in physical memory is the one selected for replacement. Poorest replacement policy
Worst Fit
-Keep linked list of free blocks
-Search the whole list on each allocation
-Choose block that worst matches the request
-Save excess for later
-Merge adjacent free blocks during release operation
Next Fit
-Keep linked list of free blocks
-Start where the last search left off
-Scan the list for the first block that comes closest to matching the needs of allocation
-Merge adjacent free blocks during release opertion
Overlays
, Programmer breaking code into pieces that fit into RAM. These pieces, called overlays, are loaded and
unloaded by the program
Page Table
Table that holds VA -> PA translations (Virtual address to physical address)
Thrashing
a process is busy swapping pages in and out. Causes : not having enough pages. Effects: Low CPU
utilization, operating system thinking that it needs to increase the degree of multiprogramming, or
adding another process to the system
A parser will NOT check to see that the input is semantically correct
Child processes canNOT change variables in its parent process
new processes are created by the fork() system call
exec() is..
a functionality of an operating system that runs an executable file in the context of an already existing
process, replacing the previous executable
Two UNIX/Linux processes may simultaneously have open file descriptors that...
refer to the same open file description
INET domain sockets can only send messages to...
a different machine
The UNIX/Linux OS does NOT allow multiple processes per thread
A function is said to be thread-safe if..
it can be called from multiple threads without unwanted interation between the threads
For a given mutex, if 1+ threads are blocked on a call to pthread_mutex_lock() and the thread that is
holding the lock calls pthread_mutex_unlock()..
exactly one of the unblocked threads will be unblocked and thus able to lock the mutex
pthread_exit is
a Pthead function that terminates the calling thread and makes the value (value_ptr) available to any
successful join with the terminting thread
When programming via threads, a ________ would give each thread it's own unique copy
stack
An application that allows two different machines to communicate using a socket requires..
one of the machines to implement a server sockets an the other a client socket
