Maekawa Distributed Mutual Exclusion

A distributed mutual exclusion program implemented with Maekawa Algorithm

Author: Hao Luo (yvetterowe1116@gmail.com)

Usage

$> python mutex.py -cs_int 5 -next_req 7 -tot_exec_time 15 -option 1

Arguments:

• cs_int (required): time (milliseconds) a node spends in the critical section
• next_req (required): time (milliseconds) a node waits after exiting the critical section before it requests another critical section entrance
• tot_exec_time (required): total execution time (seconds) for a node
• option (optional): 1 means display message log on screen

Outputs:

• Each node prints to the screen the following log whenever it enters the critical section (regardless of the option value):

   $> Time Node_ID Node_List

  • Time: system time at which the node enters the critical section
  • Node_ID: identifier of the node entering the critical section
  • Node_List: set of node identifiers from whom this node has obtained permission to enter the critical section

• Additionally, when option is specified as 1, each node should also print to the screen a log whenever it receives a message from another node:

   $> Time Node_ID Sender_ID Message_Type

  • Time: systime time at which the log is printed
  • Node_ID: identifier of the node printing the log
  • Sender_ID: identifier of the node that sent the message
  • Message_Type: type of the received message

Files

• mutex.py: main program entrance
• maekawa.py: implements system setup
• node.py: implements node functionality
• enum_type.py: defines some enum types
• message.py: defines message format
• config.py: program configuration (number of nodes, buffer size, port number)
• utils.py: implements utility functions
• logging.py: implements logging functions
• README.md: this file

Setup

• Python version >= 2.7

Issues

• Currently only works when the number of nodes is a perfect square (4, 9, 16,...)