Name: elR10090 Date: 03/26/2001



Java HotSpot VM (build 1.4.0-beta-b56) fails to start running -Xrunjcov
if the block or default gathering mode of Jcov is specified.

The program used Jcov is compiled by oldjavac that supports required -Xjcov
option for block gathering mode, as described in Jcov guide:

  oldjavac -Xjcov jcov001.java

After Java VM is started using the following command line options:

  java -XX:+EnableJVMPIInstructionStartEvent -Xrunjcov:file=jcov001.jcov jcov001

it exits with the following error message:

  *** JCOV error : cannot enable JVMPI event : JVMPI_EVENT_INSTRUCTION_START
  Error occurred during initialization of VM
  -Xrun library failed to init: jcov

This error is observed for Merlin on any platform.
Use of Ladybird does not produce this error.

This failure affects following JVMPI tests from testbase_nsk testsuite:

    nsk/jvmpi/Jcov/jcov001
    nsk/jvmpi/Jcov/jcov002
    nsk/jvmpi/Jcov/jcov003
    nsk/jvmpi/Jcov/jcov004
    nsk/jvmpi/Jcov/jcov005
    nsk/jvmpi/Jcov/jcov006
    nsk/jvmpi/Jcov/jcov007
    nsk/jvmpi/Jcov/jcov008
    nsk/jvmpi/Jcov/jcov009
    nsk/jvmpi/Jcov/jcov010
    nsk/jvmpi/Jcov/jcov011
    nsk/jvmpi/Jcov/jcov012
    nsk/jvmpi/Jcov/jcov013
    nsk/jvmpi/Jcov/jcov014
    nsk/jvmpi/Jcov/jcov015
    nsk/jvmpi/Jcov/jcov016
    nsk/jvmpi/Jcov/jcov017
    nsk/jvmpi/Jcov/jcov018
    nsk/jvmpi/Jcov/jcov019
    nsk/jvmpi/Jcov/jcov020
    nsk/jvmpi/Jcov/jcov021

These tests may be found under the src directory of testbase_nsk.
The testbase_nsk location is:

    /net/sqesvr.eng/export/vsn/VM/merlin/testbase/testbase_nsk

To reproduce the failure please use 'doit.sh' script found
in the directory:

    /net/sqesvr.eng/export/vsn/GammaBase/Bugs/<this bug number>

Use:
    sh doit.sh $JAVA_HOME

Execution using Merlin produces:
================================
Compiling test classes...
java version "1.4.0-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta-b56)
Java HotSpot(TM) Client VM (build 1.4-beta-B56, mixed mode)
*** JCOV error : cannot enable JVMPI event : JVMPI_EVENT_INSTRUCTION_START
Error occurred during initialization of VM
-Xrun library failed to init: jcov
Java exit code= 1

Execution using Ladybird produces:
==================================
java version "1.3.1-rc1"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1-rc1-b19)
Java HotSpot(TM) Client VM (build 1.3.1-rc1-b19, mixed mode)
Java exit code= 0


The same bug for kestrel is marked as integrated:

    #4297121: JVMPI: can not enable INSTRUCTION_START event

As one of the authors of Jcov Konstantin S. Bobrovsky (###@###.###)
states this error can relate to the following bugs:

    #4418774: JVM/PI with jcov agent hangs in CLASS_LOAD event
    #4296551: Jcov expects a pair of CLASS_LOAD_HOOK/CLASS_LOAD events to be atomic

======================================================================