[OpenJDK 2D-Dev] [9] Review Request- JDK-8152971- JNI Warning with -Xcheck:jni

[Prahalad Kumar Narayanan]

Hello Everyone on Java2D Forum

Good day to you.

A Quick follow-up on webrev to fix the following issue
      Bug ID     : JDK-8152971  / -Xcheck:jni - warning in native method
      Bug Link : https://bugs.openjdk.java.net/browse/JDK-8152971?filter=-1

Updated webrev link:  http://cr.openjdk.java.net/~pnarayanan/8152971/webrev.01/

Description on Changes
      . The previous webrev contained changes to additional files which are not related to the current bug in concern.
      . Henceforth, the updated webrev limits the changes to only fontpath.c and a Jtreg test script to verify the change.

Regarding Build & Test
      . Though the changes pertain to windows specific code, internal build system was triggered to ensure safe build on all supported platforms.
      . In addition, no new Jtreg failures were found with the proposed changes.

Kindly review the changes at your convenience & provide your feedback.

Thank you for your time in review
Have a good day

Prahalad N.


-----Original Message-----
From: Prahalad Kumar Narayanan 
Sent: Wednesday, June 22, 2016 3:20 PM
To: 2d-dev at openjdk.java.net
Cc: Philip Race; Prasanta Sadhukhan; Jayathirth D V; Praveen Srivastava
Subject: [9] Review Request- JDK-8152971- JNI Warning with -Xcheck:jni

Hello Everyone, on Java2D Group

Good day to you.

Please find herewith, webrev changes to fix the bug-
      Bug ID     : JDK-8152971  / -Xcheck:jni - warning in native method
      Bug Link : https://bugs.openjdk.java.net/browse/JDK-8152971?filter=-1

      Webrev : http://cr.openjdk.java.net/~pnarayanan/8152971/webrev.00/

Description on Bug:
     1.  Too many JNI warnings are reported in the native functions when test-code is run with VM Option:  -Xcheck:jni
     2.  The warnings can be classified into 2 categories
                 a.  JNI warnings that are thrown due to the missing exception checks after an Up call ( JNI function invoking Java method )
                 b.  JNI warnings that are thrown due to increased usage of Local Reference objects.

Description on the Fix:
     1.  File : FontPath.c
                   Added JNIEnv->ExceptionCheck() and ExceptionClear() where Up call is invoked. 
                           The checks are added only to the valid Up calls as per JNI spec.

                   Added JNIEnv->DeleteLocalRef where the native functions created Java side objects but did not delete their local reference after usage.
                           A few of the native functions get invoked as Callbacks to Windows APIs following the font enumeration.
                           Therefore at each callback, the count of active local references would increase. 
                                    Over time, the active local references would exceed the planned number of local references set by JVM.

     2.  File : awt_Component.cpp
                   Added JNIEnv->ExceptionCheck() and ExceptionClear() where an Up call displayed a JNI warning while running the Jtreg test script.
                   Information on Jtreg test script is given below.

     3.  File : LoadFontsJNICheck.sh
                   The shell script is already a part of JTreg test case & invokes LoadFontsJNICheck with -Xcheck:jni VM option
                   However, the script was configured to run only on Mac OS. Now, the script is modified to run on windows, linux and mac systems.
                                This way, the code changes can be checked for proper execution with test-case.

Kindly review the changes at your convenience and share your feedback.

Thank you for your time in review
Have a good day

Prahalad N.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openjdk.java.net/pipermail/2d-dev/attachments/20160624/c8c33743/attachment.html>