CSS 430: Code Examples

All source files are located in the following directories under a sub-directory of /usr/apps/CSS430/examples/ at the LAB320: uw1-320-lab.uwb.edu. If you run them on Ubuntu, please use the source code on LAB320.

OS Structures:

Comes back to the system 1 or 2 minutes later and check if tmp has been created.
Program Sub Directory Descriptions Source Files
Shell Scripts shellscripts/ These two are shell script examples. The sum10.sh simply prints out integers from 1 to 10. The sleepNhello.sh sleeps 1 minute and writes "Hello" in the tmp file. In Unix, if you run a process in background with the "nohup" option, that process can continue running even after your log out from the system. To see this behavior, 
   sum10
   nohup sleepNhello &
   exit
sleepNhello.sh, sum10.sh

Process Synchronization:

Program Sub Directory Descriptions Source Files
Producer and consumer bundedbuffer/ This is an example of a producer and a consumer thread that shares a bounded buffer. The producer repeats entering an incremented interger number into the bounded buffer, from which the consumer picks up and prints out those integers. Without a proposer synchronization, the consumer may not receive correctly incremented integers. The count.cpp program will find such a gap among integers printed out from the consumer. Run by typing: 
   java ProducerConsumer | count
ProducerConsumer.java, count.cpp
Unix semaphores semaphores/ 

This is a sample program that uses the Unix semop( ) system
call.  Three processes allocate a Unix shared region, repeatedly go
into a critical section enbraced with P and V operations, and properly
increment an integer in that region. To see a correct behavior, run by 
typing:

   sem
                  or
   sem | count


You can see the shared integer incremented sequentiall.
sem.cpp, count.cpp

Memory Management:

Program Sub Directory Descriptions Source Files
Dynamic link dynamiclink/ The dynamiclink.cpp program uploads executable file into its memory space at run time and executes functions in this executable code. There are three dynamic-linking libraries: lib1.c, lib2.c, and lib3.cpp, each including func1 and func2. In particular, those two functions in lib3.cpp are overloaded. To see how dynamiclink.cpp links those three libraries to itself, run by typing: 
   dyn_cpp
   library name = ./lib1
   function name = func1
   library name = ./lib1
   function name = func2
   library name = ./lib2
   function name = func1
   library name = ./lib2
   function name = func2
   library name = ./lib2
   function name = func3
   library name = ./lib3
   function name = func1
   library name = ./lib3
   function name = func1__Fv
dynamiclink.cpp, lib1.c lib2.c lib3.cpp lib1.s

Virtual Memory:

Program Sub Directory Descriptions Source Files
Matrix muliplication cache/ This computes the multiplication of two matrices a[400][400] and b[400][400] twice. The first computation is just ordinary multiplication, while the second computation flips b[400][400] in diagonal, so that it utilize the cache and virtual memory more effectively. To see this difference, run by typing 
   matrix
matrix.c

File System:

Program Sub Directory Descriptions Source Files
File sharing fileptrs/ The parent.cpp program spawns two children The parent and the first child executes the same program, (i.e., parent.cpp). The second child executes the child.cpp. Since those two children inherit the pointers to the same file strcutre table entry, all the processes share the same file descriptor #3 and increments the same file pointer in concurrent. The another.cpp program runs independently of the other processes, and thus reads the same file from its top. To see this difference, run by typing 
   parent
parent.cpp, child.cpp, another.cpp sample.dat