HP, it is sleep/wake/check. it is up to the process to acquire the
resource. AFAIK, there is no message-passing type of algorithm to
tell waiting (whether spinning or sleeping) processes when the
semaphore becomes unset ( ie the resource is available ) Sleeps
are expensive in Latchville, and you can track their occurence
via v$latch_waits and the SLEEP* columns.
hope this partial answer helps.
-----Original Message-----
From: Henry Poras [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, March 13, 2001 10:25 PM
To: Multiple recipients of list ORACLE-L
Subject: Oracle Internals
I have been rereading Steve Adam's book a bit more carefully and have a
question. Just wondering if anyone has any answers.
When talking about latch sleeps, the book states "a process sleeping for a
latch waits on its semaphore". However, latches don't support queuing and a
number of processes may be waiting for the same latch. If I am sleeping and
the latch frees, who knows I need that semaphore? Are all waiting processes
posted with the semaphores going on/off/on/off? or is no semaphore posted
and the processes go sleep/wake/check/sleep/wake/check? I can't quite
picture the details here.
Henry
--------
Think you know someone who can answer the above question? Forward it to them!
to unsubscribe, send a blank email to [EMAIL PROTECTED]
to subscribe send a blank email to [EMAIL PROTECTED]
Visit the list archive: http://www.LAZYDBA.com/odbareadmail.pl
Tell yer mates about http://www.farAwayJobs.com
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Henry Poras
INET: [EMAIL PROTECTED]
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
San Diego, California -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from). You may
also send the HELP command for other information (like subscribing).
