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Created attachment 512695 [details] Log file Description of problem: When selecting "Show Allocation Stack Trace" for an item in a memory profiler snapshot of Tomcat 6, only an indication of an exception appears. The attached log file shows the stack trace. Version-Release number of selected component (if applicable): tomcat6-6.0.32-5.fc15.noarch java-1.6.0-openjdk-1.6.0.0-58.1.10.2.fc15.x86_64 visualvm-1.3.2-1.2.8.fc15.x86_64 How reproducible: Only for snapshots taken when Tomcat was busy. Later snapshots of the same process work fine. Steps to Reproduce: 1. Select the Tomcat process in VisualVM. 2. Select "Record allocations stack traces" in "Memory settings" 3. Start the memory profiler 4. Take a snapshot 5. Select "Show Allocation Stack Trace" for an item in the list Actual results: Indication of an exception Expected results: Display of memory allocation traces Additional info:
Created attachment 512697 [details] Memory snapshot
This patch provides a band-aid for the situation. It does not address the root cause of why className is null but it allows the display of the allocation stack trace. Leaving className as null prevents the whole tree from getting displayed no matter what the value of thisNodeOk is. --- netbeans/lib.profiler/src/org/netbeans/lib/profiler/results/memory/PresoObjAllocCCTNode.java~ 2010-10-29 10:00:35.000000000 -0700 +++ netbeans/lib.profiler/src/org/netbeans/lib/profiler/results/memory/PresoObjAllocCCTNode.java 2011-07-13 11:47:20.000000000 -0700 @@ -274,6 +274,8 @@ } } + if (className == null) + className = "unknown"; // If any object allocations that happen in our own code are caught (which shouldn't happen), // make sure to conceal this data here. boolean thisNodeOk = !className.equals("org.netbeans.lib.profiler.server.ProfilerServer"); // NOI18N
I discovered warnings in /var/log/tomcat6/catalina.out Profiler Agent: JNI On Load Initializing... Profiler Agent: JNI OnLoad Initialized successfully Profiler Agent: Waiting for connection on port 5140 (Protocol version: 10) Profiler Agent: Established connection with the tool Profiler Agent: Local accelerated session Profiler Agent: 250 classes cached. Profiler Agent: 250 classes cached. *** Profiler engine warning: class sun.reflect.GeneratedSerializationConstructorAccessor25 that should be instrumented is not loaded by target VM *** Requested classloader: sun.reflect.DelegatingClassLoader@163fc47c, its class = class sun.reflect.DelegatingClassLoader, index = 3, hashcode = 373277820 *** Profiler engine warning: target VM cannot load class to instrument sun.reflect.GeneratedSerializationConstructorAccessor25 *** probably it has been unloaded recently ... (about 50 more classes that could not be loaded) Profiler Agent: Redefining 100 classes at idx 0, out of total 1183 Profiler Agent: Redefining 100 classes at idx 100, out of total 1183 ... Profiler Agent: Redefining 83 classes at idx 1100, out of total 1183 Profiler Agent Warning: Cannot convert 0x7f7614000b70 Profiler Agent Warning: Cannot convert 0x7f7614000b78 ... (298 different values; warnings displayed about 880,000 times) Profiler Agent Warning: Cannot convert 0x7f763c00aef0
This message is a notice that Fedora 15 is now at end of life. Fedora has stopped maintaining and issuing updates for Fedora 15. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At this time, all open bugs with a Fedora 'version' of '15' have been closed as WONTFIX. (Please note: Our normal process is to give advanced warning of this occurring, but we forgot to do that. A thousand apologies.) Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, feel free to reopen this bug and simply change the 'version' to a later Fedora version. Bug Reporter: Thank you for reporting this issue and we are sorry that we were unable to fix it before Fedora 15 reached end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged to click on "Clone This Bug" (top right of this page) and open it against that version of Fedora. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. The process we are following is described here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping