> The implementation of the JVM TI `GetObjectMonitorUsage` does not match the
> spec.
> The function returns the following structure:
>
>
> typedef struct {
> jthread owner;
> jint entry_count;
> jint waiter_count;
> jthread* waiters;
> jint notify_waiter_count;
> jthread* notify_waiters;
> } jvmtiMonitorUsage;
>
>
> The following four fields are defined this way:
>
> waiter_count [jint] The number of threads waiting to own this monitor
> waiters [jthread*] The waiter_count waiting threads
> notify_waiter_count [jint] The number of threads waiting to be notified by
> this monitor
> notify_waiters [jthread*] The notify_waiter_count threads waiting to be
> notified
>
> The `waiters` has to include all threads waiting to enter the monitor or to
> re-enter it in `Object.wait()`.
> The implementation also includes the threads waiting to be notified in
> `Object.wait()` which is wrong.
> The `notify_waiters` has to include all threads waiting to be notified in
> `Object.wait()`.
> The implementation also includes the threads waiting to re-enter the monitor
> in `Object.wait()` which is wrong.
> This update makes it right.
>
> The implementation of the JDWP command `ObjectReference.MonitorInfo (5)` is
> based on the JVM TI `GetObjectMonitorInfo()`. This update has a tweak to keep
> the existing behavior of this command.
>
> The follwoing JVMTI vmTestbase tests are fixed to adopt to the
> `GetObjectMonitorUsage()` correct behavior:
>
> jvmti/GetObjectMonitorUsage/objmonusage001
> jvmti/GetObjectMonitorUsage/objmonusage003
>
>
> The following JVMTI JCK tests have to be fixed to adopt to correct behavior:
>
> vm/jvmti/GetObjectMonitorUsage/gomu001/gomu00101/gomu00101.html
> vm/jvmti/GetObjectMonitorUsage/gomu001/gomu00101/gomu00101a.html
> vm/jvmti/GetObjectMonitorUsage/gomu001/gomu00102/gomu00102.html
> vm/jvmti/GetObjectMonitorUsage/gomu001/gomu00102/gomu00102a.html
>
>
>
> A JCK bug will be filed and the tests have to be added into the JCK problem
> list located in the closed repository.
>
> Also, please see and review the related CSR:
> [8324677](https://bugs.openjdk.org/browse/JDK-8324677): incorrect
> implementation of JVM TI GetObjectMonitorUsage
>
> The Release-Note is:
> [8325314](https://bugs.openjdk.org/browse/JDK-8325314): Release Note:
> incorrect implementation of JVM TI GetObjectMonitorUsage
>
> Testing:
> - tested with mach5 tiers 1-6
Serguei Spitsyn has updated the pull request with a new target base due to a
merge or a rebase. The incremental webrev excludes the unrelated changes
brought in by the merge/rebase. The pull request contains five additional
commits since the last revision:
- Merge
- review: fixed issues in get_object_monitor_usage; extended test coverage in
objmonusage003
- Merge
- review: thread in notify waiter list can't be BLOCKED
- 8324677: Specification clarification needed for JVM TI GetObjectMonitorUsage
-------------
Changes:
- all: https://git.openjdk.org/jdk/pull/17680/files
- new: https://git.openjdk.org/jdk/pull/17680/files/69ba5e7e..182cd07c
Webrevs:
- full: https://webrevs.openjdk.org/?repo=jdk&pr=17680&range=04
- incr: https://webrevs.openjdk.org/?repo=jdk&pr=17680&range=03-04
Stats: 6592 lines in 396 files changed: 3981 ins; 1259 del; 1352 mod
Patch: https://git.openjdk.org/jdk/pull/17680.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/17680/head:pull/17680
PR: https://git.openjdk.org/jdk/pull/17680
