Out: Friday, April 10th


Due: Friday, April 17th, *BEFORE CLASS STARTS*

Turn In: https://catalysttools.washington.edu/collectit/dropbox/andosw/5665



Read the text:  Silberschatz Chapters 4-5


Problems in text:


3.7, 4.2, 4.3, 4.8, 4.11 (assuming a single kernel thread is
powering all of the user-level threads), 5.2, 5.3, 5.5, 5.15



4.x
	For this question you are to use the pthread library to write a simple 
	producer/consumer style program.  Your program should create two threads: 
	one to produce data and one to consume data.  The data that you are 
	producing and consuming are just random integers between 0 and 99.  Your 
	code should implement the following pseudo code:

	main:
		initialize buffer to store data.  The buffer needs to store 32 ints.
		initialize any mutex/condition variables
		create/start threads
		join threads
		free buffer/memory
		return

	producing thread:
		Loop 100 times
			If buffer is full
				print "buffer full, waiting..."
				wait for buffer to not be full
			endif
			generate random int between 0 and 99 and add it to the buffer
			print "produced x" where x is the int produced
			sleep either 1 second or 4 seconds.  50% chance for each
		endloop	

	consuming thread:
		Loop 100 times
			If buffer is empty	
				print "buffer empty, waiting..."
				wait for buffer not to be empty
			endif
			consume an int
			print "consumed x" where x is the int consumed
			sleep either 1 second or 5 seconds.  50% chance for each
		endloop

	*If the buffer is ever full, the producing thread does not add to it.
	*If the buffer is ever empty, the consuming thread does not consume anything.
	*It might help to think of your buffer as a circular array.
	*Make sure your buffer is coherent.  ie. use a mutex!
	*When waiting, use the pthread_cond_wait() function
	*Make sure you signal when the buffer is not full or not empty with pthread_cond_signal()
	*Make sure you compile with the -pthread flag