On Tue, 19 Sep 2023 09:25:33 GMT, Axel Boldt-Christmas <[email protected]>
wrote:
>> ObjectMonitorIterator fails to return the most resent monitor added. It
>> start with returning the `nextOM()` ObjectMonitor from the `_head`
>> ObjectMonitor but fails to ever return the `_head` ObjectMonitor.
>> The current implementation can also not handle that the `_head` is nullptr
>> (no monitors in the system) and returns a null ObjectMonitorIterator. Which
>> is interpreted as `monitor list not supported, too old hotspot VM`.
>>
>> Changed the iterator to keep return the current monitor (starts with
>> `_head`) and decoupled `_head == nullptr` from the question if
>> ObjectMonitorIterator is supported.
>>
>> Testing:
>> * Passes all `serviceability/sa` tests
>> * Passed tier 1-5
>> * Passed GHA
>
> Axel Boldt-Christmas has updated the pull request incrementally with one
> additional commit since the last revision:
>
> Removed unnecessary comment
src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/ObjectSynchronizer.java
line 86:
> 84:
> 85: ObjectMonitorIterator() {
> 86: mon = new ObjectMonitor(inUseList);
How did this ever work? `inUseList` is an address that points to a
`MonitorList`, not an `ObjectMonitor`. Your new code has it right, but it seems
that this old code would have failed either during construction, or during the
first `mon.nextOM()` call.
test/hotspot/jtreg/runtime/cds/appcds/dynamicArchive/DynamicSharedSymbols.java
line 41:
> 39: * @build jdk.test.whitebox.WhiteBox
> 40: * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar loadclass.jar
> JCmdTestLingeredApp
> 41: * jdk.test.lib.apps.LingeredApp
> jdk.test.lib.apps.LingeredApp$1 jdk.test.lib.apps.LingeredApp$SteadyStateLock
Copyright needs updating in this file.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/15782#discussion_r1332246787
PR Review Comment: https://git.openjdk.org/jdk/pull/15782#discussion_r1330761695
