UTSA CS 3733 Operating Systems Assignment 4 Comments Fall 2003

CS 3733 Operating Systems, Fall 2003 Assignment 4 Comments

Assignment 4 was worth 30 points.

Do not use #include to include source files, only header files
In fdreceiver, open can be interrupted by a signal so you should use r_open.
When you create the file in fdreceiver open should have three parameters, or use r_open3.
You must test with asynchronous signals, not just with raise.
You must save and restore errno in the signal handler.
The signal handler must take a parameter (or 3) even if you are not using the parameters in the signal handler.
There is a problem printing the number of files and the total number of bytes in the signal handler if signals are enabled when these are being changed.
When using lint run it once for each executable with all files that are linked in that executable.
Do not exit the program in a subroutine when an error occurs.

Comments about the extra credit:

Only one person got it essentially correct.

The structure containing the names and sizes is a shared variable, shared between the main program and the signal handler.

You need to block the signal when you are updating the structure containing the names and sizes.

An assignment statement involving a pointer does not have to be atomic.

You do not have to free the linked list since it is used until the program exits.