Hi, I have passed my assignment.

[Jesse Xie Y.S.]

Date Taken: 2005-10-27 06:45:22.437

Grade: P
Score: 362
Comment: This report shows the total number of points awarded for each section. The maximum number of points is 400, to pass you need a score of 320. Section Summary: Section Max Actual Points Points General Con: 100 90 Documentation: 70 65 OOD: 30 30 GUI: 40 27 Locking: 80 80 Data Store: 40 40 Network Server: 40 30 Total: 400 362

[Barry Gaunt]

Congratulations! Hey 80:80 locking - you are one of the elite!

[Alan Morgan]

Congrats

So what was your locking approach ?
I have seen some really complex ones on here and I'm starting to get worried.
Hopefully its nice and straightforward

[Andrew Monkhouse]

Congratulations Jesse

[Mihai Radulescu]

Congrats,

I have a small question, I see that you have 80 on lockig.

What look strategy you use ?

[Jesse Xie Y.S.]

I am so happy that I foregot to say thanks to JavaRanch.
Because I've learned so lots from JavaRanch.
---------------------------------------------

My lock implementation is very simple.
1. I uses a static Random long seed initialized once JVM started, as a seed of looked cookie generation.
2. I uses a map to store all current available mapping of locked record and cookie. The key of the entry is a record number, the value mapped to the key (record) is the cookie held by a client.
3. I uses the object locked of the map to synchronize the record lock and unlock process.
4. I notify all thread waiting on the object locked of map only after unlocked a record successfully.
5. Make sure that the process of checking if a record is locked by other thread or checking if the record is exist, before locked a record, should be keep in synchronized block.

[Davinder Kohli]

How long after you took your essay exam, did you get your results?

[Mihai Radulescu]

Hi Jesse I still have a question. Whar you realy mean by

Make sure that the process of checking if a record is locked by other thread or checking if the record is exist, before locked a record, should be keep in synchronized block.

You mean that the the isLock(int):boolean metohd must be keeped in to a synchronized block - synchronized with the same instance like lock(int) metod ? By lock(int) I mean the menthod that locks a record in the lock manager.

Thanks,
Mihai.
[ October 30, 2005: Message edited by: Mihai Radulescu ]

[Andrew Monkhouse]

Moved to the Sun Certification Results forum.

Regards, Andrew