Assignment 3 MergeSort

1
Assignment 3 - MergeSort

• The object of this assignment is to
• Write a Java program that utilizes a parallel
  mergesort using threads
• Examine the performance of the program over a
  range of workload sizes (number of items to be
  sorted)
• Duplicate random numbers will be allowed in the
  dataset.
• The range of random numbers should be related to
  the size of the dataset (dataset of size 16
  random numbers between 1 and 16)
• The number of parallel threads will be half the
  size of the dataset.

2

• The main program generates a random dataset of
  fixed size
• (a timer starts)
• Create a set of threads
• Begin the distribution of data to a first
  thread
• Threads distribute data to other threads (as per
  the algorithm in the text with corrections
  discussed in class)
• When a thread has but two items in the dataset,
  it sorts those items
• Threads pass sorted subsets for mergesorting
• The sorted dataset is passed to the main program
• (the timer stops) number of items and time to
  sort are printed

3

• Run a variety of datasets (powers of two),
  recording the time to completion for each.
• Evaluate your numbers against the Big O
  estimate of algorithm performance
• Extra Credit try to determine constants of
  proportionality from your experimental runs of
  varying size dataset, that will make the general
  estimate of performance a predictor of the
  performance you actually observed.