Presentation of practical exercise 4

1
Presentation of practical exercise 4

• Discussion
• More questions?
• TDt4190 Newsgroup

2
Program Testing

• Make your program downloadable at demonstration
  session.
• Use the assigned port number of your group at the
  demonstration.
• Do not print-out the file final_results.txt.
• 70 pages text.
• We will keep the electronic version of the file.
• Submit your reports to the assistant.
• Short description (max 5 pages 2000 words) on
  program design.
• Program source code (style and documentation).

3
Program Testing

• One Windows server.
• kjor_test_case.bat
• kjor_en.bat
• kjor_to.bat
• Many Windows server.
• See guide on TDT4190 website
• kjor_3.bat
• kjor_5.bat

4
lock method in Resource.java

• public synchronized boolean lock(int
  transactionId)
• if(lockOwner null)
• lockOwner new Integer(transactionId)
• return true
• else
• // Wait for the lock
• try
• wait()
• catch (InterruptedException ie)
• return false
• lockOwner new Integer(transactionId)
• return true

The thread releasesownership of this monitor
5
Program Testing Results of sample test cases A-J
6

• S4 or S1 can detect a deadlock.
• Which transaction will be aborted?
• T2 at S4 or S4 tells S3 or S1 to abort their
  transactions

7
Program Testing

• Main requirement
• Detecting deadlocks in both timeouts and edge
  chasing scenarios
• Optional (i.e., not required)
• Restart aborted transactions
• Priority of transactions (e.g., life-time, local
  vs. remote servers)