Hi David, Serguei, I updated webrev for 8242428. Could you review again? This change migrate to use direct handshake for GetStackTrace() and GetThreadListStackTraces() (when thread_count == 1).
http://cr.openjdk.java.net/~ysuenaga/JDK-8242428/webrev.01/ VM_GetThreadListStackTrace (for GetThreadListStackTraces) and VM_GetAllStackTraces (for GetAllStackTraces) have inherited VM_GetMultipleStackTraces VM operation which provides the feature to generate jvmtiStackInfo. I modified VM_GetMultipleStackTraces to a normal C++ class to share with HandshakeClosure for GetThreadListStackTraces (GetSingleStackTraceClosure). Also I added new testcases which test GetThreadListStackTraces() with thread_count == 1 and with all threads. This change has been tested in serviceability/jvmti serviceability/jdwp vmTestbase/nsk/jvmti vmTestbase/nsk/jdi vmTestbase/nsk/jdwp. Thanks, Yasumasa On 2020/06/24 15:50, Yasumasa Suenaga wrote:
Hi all, Please review this change: JBS: https://bugs.openjdk.java.net/browse/JDK-8242428 webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8242428/webrev.00/ This change replace following VM operations to direct handshake. - VM_GetFrameCount (GetFrameCount()) - VM_GetFrameLocation (GetFrameLocation()) - VM_GetThreadListStackTraces (GetThreadListStackTrace()) - VM_GetCurrentLocation GetThreadListStackTrace() uses direct handshake if thread count == 1. In other case (thread count > 1), it would be performed as VM operation (VM_GetThreadListStackTraces). Caller of VM_GetCurrentLocation (JvmtiEnvThreadState::reset_current_location()) might be called at safepoint. So I added safepoint check in its caller. This change has been tested in serviceability/jvmti serviceability/jdwp vmTestbase/nsk/jvmti vmTestbase/nsk/jdi vmTestbase/ns k/jdwp. Also I tested it on submit repo, then it has execution error (mach5-one-ysuenaga-JDK-8242428-20200624-0054-12034717) due to dependency error. So I think it does not occur by this change. Thanks, Yasumasa
