On 03/06/2020 23:28, serguei.spit...@oracle.com wrote:
Hi David and Alex,
My understanding is that previous implementation collected logs
separately for each thread in TLS, and at the end, merged and sorted out
the output by log id.
So, the result is that all messages are serialized at the end.
Alex changed the implementation but the result is the same - all log
messages are serialized.
There are two tests which use the LockFreeLogger.
Another one is: test/jdk/java/lang/Thread/ThreadStateController.java .
Does the ThreadStateController.java work okay after the fix?
ThreadStateController is an utility class used only by
ThreadMXBeanStateTest.java.
ThreadMXBeanStateTest.java is problem-listed, but I verified that
logging works in the test.
--alex
Thanks,
Serguei
On 3/5/20 10:54, Alex Menkov wrote:
Hi David,
Thanks you for the review.
On 03/04/2020 17:50, David Holmes wrote:
Hi Alex,
On 5/03/2020 10:30 am, Alex Menkov wrote:
Hi all,
please review the fix for
https://bugs.openjdk.java.net/browse/JDK-8240340
webrev:
http://cr.openjdk.java.net/~amenkov/jdk15/ThreadMXBean_Locks_test/webrev/
changes:
- assertThreadState method: don't re-read thread state throwing
exception (as we got weird error like "Thread WaitingThread is at
WAITING state but is expected to be in Thread.State = WAITING");
- added proper test shutdown on error (made all threads "daemon",
interrupt waiting thread if CheckerThread throws exception);
- if CheckerThread detects error, propagate the exception to main
thread;
The test changes seem fine.
- fixed LockFreeLogger class - it should work for logging from
several threads, but it doesn't. I prefer to simplify it just to
keep ConcurrentLinkedQueue<String>.
LockFreeLogger is also used by ThreadMXBeanStateTest test, but only
by a single thread.
I don't understand your changes here as you've completely changed the
intended design of the logger. The original accumulates log entries
per-thread and then spits them all out (though I'm not clear on the
exact ordering - I don't how to read that stream stuff). The new code
just creates a single queue of log records interleaving entries from
different threads. The simple logger may be all that is needed but it
seems quite different to the intent of the original.
Testing changes in the test I discovered that there is something wrong
with the logger - it printed only part of the records, so I have to
look at the LockFreeLogger class and I don't understand how it was
supposed to work.
About ordering in cumulative log: each record has Integer which used
to sort log entries from all threads (i.e. records from different
threads are printed at the order which log() was called).
Looking at allRecords/records stuff I don't understand how it should
be used. To get logs from different threads in one logger, we needs
one instance. So we create LockFreeLogger (in main thread) and ctor
creates ThreadLocal record and register it in allRecords. Logging from
main thread works fine, but if any other thread tries to log, 1st
log() call creates its own ThreadLocal records (by records.get()) and
log records from this thread go there. But this ThreadLocal records is
not registered in allRecords, so this logging won't be included in
final log.
Looks like we need to change log() to something like
Map<Integer, String> recs = records.get();
if (recs.isEmpty()) {
allRecords.add(recs);
}
recs.put(id, String.format(format, params));
But all this stuff do exactly the same as simple ConcurrentLinkedQueue
(i.e. lock free ordered list).
At least I don't see other rationale in the stuff.
--alex
Thanks,
David
--alex
