Hi Dan,
On 3/18/20 5:30 PM, Daniel D. Daugherty wrote:
On 3/17/20 4:14 PM, Patricio Chilano wrote:
Hi all,
Please review the following patch:
Bug: https://bugs.openjdk.java.net/browse/JDK-8240902
Webrev: http://cr.openjdk.java.net/~pchilanomate/8240902/v1/webrev/
src/jdk.jdi/share/native/libdt_shmem/shmemBase.c
L411: int attempts = 10;
L420: sysSleep(200);
I presume that this is a 200 millisecond sleep so this new loop
will delay a closeStream() call by at most 2 seconds. You may
want those literals to be #define'ed values at the top of the
file, e.g., like this one:
#define MAX_GENERATION_RETRIES 20
Your choice on the names of the new #defines if you choose to
do that. You might even consider putting them close to
"typedef struct SharedMemoryConnection".
Update: Oh yuck! Now I see that there is existing code that
does the same kind of looping with sysSleep() calls when the
linger option is set. I revise my comment: You're following
the existing style in the function so go with what you have.
Ok, I left the loop as it is now.
Don't forget to update the copyright year before you push.
Done.
L379: closeStream(Stream *stream, jboolean linger, unsigned int
*refcount )
nit - please delete space before ')'.
Done.
L412: MemoryBarrier(); /* Prevent load of refcount to float
above. */
typo: s/to float/from floating/
After replying to David's review I realized the enterMutex() call on
closeStream() will already provide acquire semantics so reading the
refcount will not float above. I removed the barrier.
L413: while (attempts>0) {
nit - please add spaces around '>'.
Done.
L415-418, L537, L541, L552:
nit - indent should be four spaces instead of two spaces.
Done.
The existing L546 and L549 should indented four spaces instead
of two spaces. Please fix since you there.
Done.
I'm good with the code changes. I only have nits above so I don't need
to see another webrev.
Thanks for reviewing this Dan! I might send a v2 later.
Thanks,
Patricio
Dan
Calling closeConnection() on an already created/opened connection
includes calls to CloseHandle() on objects that can still be used by
other threads. This can lead to either undefined behavior or, as
detailed in the bug comments, changes of state of unrelated objects.
This issue was found while debugging the reason behind some jshell
test failures seen after pushing 8230594. Not as important, but there
are also calls to closeStream() from createStream()/openStream() when
failing to create/open a stream that will return after executing
"CHECK_ERROR(enterMutex(stream, NULL));" without closing the intended
resources. Then, calling closeConnection() could assert if the reason
of the previous failure was that the stream's mutex failed to be
created/opened. These patch aims to address these issues too.
Tested in mach5 with the current baseline, tiers1-3 and several runs
of open/test/langtools/:tier1 which includes the jshell tests where
this connector is used. I also applied patch
http://cr.openjdk.java.net/~pchilanomate/8240902/triggerbug/webrev
mentioned in the comments of the bug, on top of the baseline and run
the langtool tests with and without this fix. Without the fix running
around 30 repetitions already shows failures in tests
jdk/jshell/FailOverExecutionControlTest.java and
jdk/jshell/FailOverExecutionControlHangingLaunchTest.java. With the
fix I run several hundred runs and saw no failures. Let me know if
there is any additional testing I should do.
As a side note, I see there are a couple of open issues related with
jshell failures (8209848) which could be related to this bug and
therefore might be fixed by this patch.
Thanks,
Patricio
