Explain what the kernel must provide for a user-level implementation of threads, such as Java on
UNIX.

What will be an ideal response?


A thread that makes a blocking system call provides no opportunity for the user-level scheduler to intervene,
and so all threads become blocked even though some may be in the READY state. A user-level implementation
requires (a) non-blocking (asynchronous) I/O operations provided by the kernel, that only initiate I/O; and (b)
a way of determining when the I/O has completed -- for example, the UNIX select system call. The threads
programmer should not use native blocking system calls but calls in the threading API which make an
asynchronous call and then invoke the scheduler.

Computer Science & Information Technology

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When two different keys “hash into” the same cell in an array, this is known as a ________.

a) error b) collision c) problem d) crash

Computer Science & Information Technology

If a file is copied from an NTFS partition to a FAT partition, the file loses its NTFS permissions completely

Indicate whether the statement is true or false

Computer Science & Information Technology

Session state information is stored in the ____ autoglobal.

A. $_GET[] B. $_POST[] C. $_SESSION[] D. $_COOKIE[]

Computer Science & Information Technology

List three recommendations with regard to good password practices.

What will be an ideal response?

Computer Science & Information Technology