Concurrency Examples

• a.sh b.sh
• c.sh d.sh
• semab.c sema.c semb.c These are three programs you can compile and run. semab initializes a semaphore, sema does a release operation on the semaphore and semb does an aquire on the semaphore. After you have run semab, try running sema and semb in different orders to see what happens. Please note that this is not a set of programs, but it does allow you to see what happens when operations are done in different orders.
• trade.c This program you can just compile and run. It forks a process and then both processes update a global counter. (Updated Nov 6.)

Shared memory examples

We are not covering shared memory in class this year.

• initshmem.c, readshmem.c
  These are two separate programs. initshmem.c initializes a shared memory segment and writes some data to it. readshmem.c attaches to the same shared memory segment and reads the data from the shared memory segment. You will need to change the file name used in ftok.
• fsm.c