On Tue, Dec 6, 2016 at 9:08 PM, Matt Sicker <boa...@gmail.com> wrote:
> Also, for some context: all classes in log4-core.jar share the same > ClassLoader in OSGi, so using one from class A can be used to load class B. > LoaderUtil tends to rely on getting whatever ClassLoader is in the current > Thread's context ClassLoader which by default is whatever ClassLoader was > used to create the Thread. In OSGi, the current thread can easily be one > created by a class outside log4j-core. The same rule applies to log4j-api > and any other log4j modules doing dynamic class loading. > > I think some uses of LoaderUtil should be looked at again as this issue is > probably present in a couple other places as well. I'll see what I can find. > Great! Thanks Matt. Gary > > On 6 December 2016 at 22:52, Matt Sicker <boa...@gmail.com> wrote: > >> In an OSGi environment, the best ClassLoader to use for something in >> log4j-core is one obtained from a class in log4j-core. Come to think of it, >> it'd be better to do something like this: >> >> LoggerContext.class.getClassLoader().loadClass(...); >> >> On 6 December 2016 at 22:39, Gary Gregory <garydgreg...@gmail.com> wrote: >> >>> I think one of the points here is that a class is loaded from a specific >>> class loader. This is not clear from the code or comments. I am not sure >>> this 100% correct either but if that fixes at least the null class loader >>> NPE then that is a good thing. Especially if the fix is less hacky than >>> inially proposed. I am open to better comments and code ;-) >>> >>> Gary >>> >>> >>> On Dec 6, 2016 8:24 PM, "Matt Sicker" <boa...@gmail.com> wrote: >>> >>> I'm not sure if that LoaderUtil line will work properly everywhere. You >>> already implicitly load the class by referencing the class's .class >>> property I think. Either way, a more amusing and surefire way to make it >>> load would be: >>> >>> ExecutorServices.class.getClassLoader().loadClass(ExecutorSe >>> rvices.class.getName()); >>> >>> Or use one of the LoaderUtil/Loader methods that takes a ClassLoader >>> argument to avoid an NPE if log4j is loaded as a bootstrap class somehow. >>> >>> ---------- Forwarded message ---------- >>> From: <ggreg...@apache.org> >>> Date: 6 December 2016 at 18:07 >>> Subject: logging-log4j2 git commit: [LOG4J2-1642] >>> To: comm...@logging.apache.org >>> >>> >>> Repository: logging-log4j2 >>> Updated Branches: >>> refs/heads/master 2eb02c827 -> bdac7f223 >>> >>> >>> [LOG4J2-1642] >>> >>> DefaultShutdownCallbackRegistry can throw a NoClassDefFoundError. >>> >>> Project: http://git-wip-us.apache.org/repos/asf/logging-log4j2/repo >>> Commit: http://git-wip-us.apache.org/repos/asf/logging-log4j2/commit >>> /bdac7f22 >>> Tree: http://git-wip-us.apache.org/repos/asf/logging-log4j2/tree/b >>> dac7f22 >>> Diff: http://git-wip-us.apache.org/repos/asf/logging-log4j2/diff/b >>> dac7f22 >>> >>> Branch: refs/heads/master >>> Commit: bdac7f223b41dfbbf204ca924d08e6ed86c76769 >>> Parents: 2eb02c8 >>> Author: Johno Crawford <jo...@sulake.com> >>> Authored: Tue Dec 6 16:07:52 2016 -0800 >>> Committer: Gary Gregory <garydgreg...@gmail.com> >>> Committed: Tue Dec 6 16:07:52 2016 -0800 >>> >>> ---------------------------------------------------------------------- >>> .../apache/logging/log4j/core/LoggerContext.java | 16 >>> +++++++++++++--- >>> .../core/util/DefaultShutdownCallbackRegistry.java | 9 +++++++-- >>> src/changes/changes.xml | 3 +++ >>> 3 files changed, 23 insertions(+), 5 deletions(-) >>> ---------------------------------------------------------------------- >>> >>> >>> http://git-wip-us.apache.org/repos/asf/logging-log4j2/blob/b >>> dac7f22/log4j-core/src/main/java/org/apache/logging/log4j/co >>> re/LoggerContext.java >>> ---------------------------------------------------------------------- >>> diff --git >>> a/log4j-core/src/main/java/org/apache/logging/log4j/core/LoggerContext.java >>> b/log4j-core/src/main/java/org/apache/logging/log4j/core/Log >>> gerContext.java >>> index 6902ade..4c4845e 100644 >>> --- a/log4j-core/src/main/java/org/apache/logging/log4j/core/Log >>> gerContext.java >>> +++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/Log >>> gerContext.java >>> @@ -16,6 +16,8 @@ >>> */ >>> package org.apache.logging.log4j.core; >>> >>> +import static org.apache.logging.log4j.core. >>> util.ShutdownCallbackRegistry.SHUTDOWN_HOOK_MARKER; >>> + >>> import java.beans.PropertyChangeEvent; >>> import java.beans.PropertyChangeListener; >>> import java.io.File; >>> @@ -52,10 +54,9 @@ import org.apache.logging.log4j.spi.AbstractLogger; >>> import org.apache.logging.log4j.spi.LoggerContextFactory; >>> import org.apache.logging.log4j.spi.LoggerRegistry; >>> import org.apache.logging.log4j.spi.Terminable; >>> +import org.apache.logging.log4j.util.LoaderUtil; >>> import org.apache.logging.log4j.util.PropertiesUtil; >>> >>> -import static org.apache.logging.log4j.core. >>> util.ShutdownCallbackRegistry.SHUTDOWN_HOOK_MARKER; >>> - >>> /** >>> * The LoggerContext is the anchor for the logging system. It maintains >>> a list of all the loggers requested by >>> * applications and a reference to the Configuration. The Configuration >>> will contain the configured loggers, appenders, >>> @@ -63,7 +64,16 @@ import static org.apache.logging.log4j.core. >>> util.ShutdownCallbackRegistry.SHUTDO >>> */ >>> public class LoggerContext extends AbstractLifeCycle >>> implements org.apache.logging.log4j.spi.LoggerContext, >>> AutoCloseable, Terminable, ConfigurationListener { >>> - >>> + >>> + static { >>> + try { >>> + // LOG4J2-1642 preload ExecutorServices as it is used in >>> shutdown hook >>> + LoaderUtil.loadClass(ExecutorServices.class.getName()); >>> + } catch (final Exception e) { >>> + LOGGER.error("Failed to preload ExecutorServices class.", >>> e); >>> + } >>> + } >>> + >>> /** >>> * Property name of the property change event fired if the >>> configuration is changed. >>> */ >>> >>> http://git-wip-us.apache.org/repos/asf/logging-log4j2/blob/b >>> dac7f22/log4j-core/src/main/java/org/apache/logging/log4j/co >>> re/util/DefaultShutdownCallbackRegistry.java >>> ---------------------------------------------------------------------- >>> diff --git a/log4j-core/src/main/java/org/apache/logging/log4j/core/uti >>> l/DefaultShutdownCallbackRegistry.java b/log4j-core/src/main/java/org >>> /apache/logging/log4j/core/util/DefaultShutdownCallbackRegistry.java >>> index 48d54b6..d2be690 100644 >>> --- a/log4j-core/src/main/java/org/apache/logging/log4j/core/uti >>> l/DefaultShutdownCallbackRegistry.java >>> +++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/uti >>> l/DefaultShutdownCallbackRegistry.java >>> @@ -72,8 +72,13 @@ public class DefaultShutdownCallbackRegistry >>> implements ShutdownCallbackRegistry >>> for (final Runnable hook : hooks) { >>> try { >>> hook.run(); >>> - } catch (final Throwable t) { >>> - LOGGER.error(SHUTDOWN_HOOK_MARKER, "Caught >>> exception executing shutdown hook {}", hook, t); >>> + } catch (final Throwable t1) { >>> + try { >>> + LOGGER.error(SHUTDOWN_HOOK_MARKER, "Caught >>> exception executing shutdown hook {}", hook, t1); >>> + } catch (final Throwable t2) { >>> + System.err.println("Caught exception logging >>> exception"); >>> + t1.printStackTrace(); >>> + } >>> } >>> } >>> state.set(State.STOPPED); >>> >>> http://git-wip-us.apache.org/repos/asf/logging-log4j2/blob/b >>> dac7f22/src/changes/changes.xml >>> ---------------------------------------------------------------------- >>> diff --git a/src/changes/changes.xml b/src/changes/changes.xml >>> index a6279b2..4fa7e54 100644 >>> --- a/src/changes/changes.xml >>> +++ b/src/changes/changes.xml >>> @@ -147,6 +147,9 @@ >>> <action issue="LOG4J2-1687" dev="ggregory" type="fix" >>> due-to="Robert Christiansen"> >>> NPE in ThrowableProxy when resolving stack in Java EE/OSGi >>> environment. >>> </action> >>> + <action issue="LOG4J2-1642" dev="ggregory" type="fix" >>> due-to="Johno Crawford"> >>> + DefaultShutdownCallbackRegistry can throw a >>> NoClassDefFoundError. >>> + </action> >>> <action issue="LOG4J2-1644" dev="ggregory" type="update" >>> due-to="Tim Gokcen, Pavel Sivolobtchik"> >>> Inefficient locking in AbstractLoggerAdapter. >>> </action> >>> >>> >>> >>> >>> -- >>> Matt Sicker <boa...@gmail.com> >>> >>> >>> >> >> >> -- >> Matt Sicker <boa...@gmail.com> >> > > > > -- > Matt Sicker <boa...@gmail.com> > -- E-Mail: garydgreg...@gmail.com | ggreg...@apache.org Java Persistence with Hibernate, Second Edition <https://www.amazon.com/gp/product/1617290459/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1617290459&linkCode=as2&tag=garygregory-20&linkId=cadb800f39946ec62ea2b1af9fe6a2b8> <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1617290459> JUnit in Action, Second Edition <https://www.amazon.com/gp/product/1935182021/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182021&linkCode=as2&tag=garygregory-20&linkId=31ecd1f6b6d1eaf8886ac902a24de418%22> <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1935182021> Spring Batch in Action <https://www.amazon.com/gp/product/1935182951/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182951&linkCode=%7B%7BlinkCode%7D%7D&tag=garygregory-20&linkId=%7B%7Blink_id%7D%7D%22%3ESpring+Batch+in+Action> <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1935182951> Blog: http://garygregory.wordpress.com Home: http://garygregory.com/ Tweet! http://twitter.com/GaryGregory
