On Tue, 20 Feb 2024 23:48:06 GMT, Serguei Spitsyn <sspit...@openjdk.org> wrote:
>> 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 incrementally with one
> additional commit since the last revision:
>
> review: addressed minor issue with use of []; corrected the test desctiption
Changes requested by lmesnik (Reviewer).
test/hotspot/jtreg/serviceability/jvmti/GetObjectMonitorUsage/ObjectMonitorUsage.java
line 42:
> 40: * - all the above is checked for both platform and virtual threads
> 41: * @requires vm.jvmti
> 42: * @compile ObjectMonitorUsage.java
No need to have explicit compile for the test code.
test/hotspot/jtreg/serviceability/jvmti/GetObjectMonitorUsage/ObjectMonitorUsage.java
line 48:
> 46: public class ObjectMonitorUsage {
> 47:
> 48: final static int JCK_STATUS_BASE = 95;
JCK_STATUS_BASE is not used, need to be removed.
test/hotspot/jtreg/serviceability/jvmti/GetObjectMonitorUsage/ObjectMonitorUsage.java
line 72:
> 70: * - zero threads waiting to be notified
> 71: */
> 72: static void test1(boolean isVirtual) throws Error {
no need to add throws for unchecked excption
test/hotspot/jtreg/serviceability/jvmti/GetObjectMonitorUsage/ObjectMonitorUsage.java
line 204:
> 202:
> 203: // test virtual threads
> 204: test1(false);
shouldn't be true here?
test/hotspot/jtreg/serviceability/jvmti/GetObjectMonitorUsage/libObjectMonitorUsage.cpp
line 37:
> 35: static jvmtiCapabilities caps;
> 36: static jint result = PASSED;
> 37: static jboolean printdump = JNI_FALSE;
if there are not too much logging, better just to enable log by default and
remove this variable
test/hotspot/jtreg/serviceability/jvmti/GetObjectMonitorUsage/libObjectMonitorUsage.cpp
line 105:
> 103: err = jvmti->GetObjectMonitorUsage(obj, &inf);
> 104: if (err == JVMTI_ERROR_MUST_POSSESS_CAPABILITY &&
> !caps.can_get_monitor_info) {
> 105: return; /* Ok, it's expected */
I think we don't need this path.
test/hotspot/jtreg/serviceability/jvmti/GetObjectMonitorUsage/libObjectMonitorUsage.cpp
line 107:
> 105: return; /* Ok, it's expected */
> 106: } else if (err != JVMTI_ERROR_NONE) {
> 107: LOG("(GetMonitorInfo#%d) unexpected error: %s (%d)\n",
you could use check_jvmti_status
test/hotspot/jtreg/serviceability/jvmti/GetObjectMonitorUsage/libObjectMonitorUsage.cpp
line 117:
> 115: LOG(">>> [%2d] owner: none (0x0)\n", count);
> 116: } else {
> 117: err = jvmti->GetThreadInfo(inf.owner, &tinf);
need to check err status.
test/hotspot/jtreg/serviceability/jvmti/GetObjectMonitorUsage/libObjectMonitorUsage.cpp
line 126:
> 124: LOG(">>> waiters:\n");
> 125: for (j = 0; j < inf.waiter_count; j++) {
> 126: err = jvmti->GetThreadInfo(inf.waiters[j], &tinf);
need to check err.
test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetObjectMonitorUsage/objmonusage003.java
line 31:
> 29:
> 30: final static int JCK_STATUS_BASE = 95;
> 31: final static int NUMBER_OF_THREADS = 16;
Better to remove the test if it already converted to avoid mess.
-------------
PR Review: https://git.openjdk.org/jdk/pull/17680#pullrequestreview-1894528980
PR Review Comment: https://git.openjdk.org/jdk/pull/17680#discussion_r1498395120
PR Review Comment: https://git.openjdk.org/jdk/pull/17680#discussion_r1498385978
PR Review Comment: https://git.openjdk.org/jdk/pull/17680#discussion_r1498396928
PR Review Comment: https://git.openjdk.org/jdk/pull/17680#discussion_r1498388601
PR Review Comment: https://git.openjdk.org/jdk/pull/17680#discussion_r1498391687
PR Review Comment: https://git.openjdk.org/jdk/pull/17680#discussion_r1498392633
PR Review Comment: https://git.openjdk.org/jdk/pull/17680#discussion_r1498393662
PR Review Comment: https://git.openjdk.org/jdk/pull/17680#discussion_r1498393291
PR Review Comment: https://git.openjdk.org/jdk/pull/17680#discussion_r1498404333
PR Review Comment: https://git.openjdk.org/jdk/pull/17680#discussion_r1498394741
