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Posted to user@commons.apache.org by Pavel Savara <pa...@intrade.com> on 2008/10/30 12:32:59 UTC
[CONFIGURATION] Deadlock during refresh properties
Hi
Commons configurations get itself stuck in deadlock when refreshing
properties using Managed reloading strategy. It seems to me it get stuck
because of fireEvent in reload method. Another access grabs lock on
synchronized (getNodeCombiner()) when trying to rebuild but Combined
configuration is one of the listeners for event es well and it gets
stuck when processing invalidate. Can anyone suggest quick fix please?
Relevant information follows. I will create bugreport as well
Thanks
Pavel
Configuration:
<configuration>
<override>
<system/>
<properties fileName="gsxweb.properties"
throwExceptionOnMissing="false"
config-name="gsxweb" config-optional="false" listDelimiter="|">
<reloadingStrategy
config-class="org.apache.commons.configuration.reloading.ManagedReloadingStrategy"/>
</properties>
</override>
</configuration>
Our Reload code:
int ln = combinedConfiguration.getNumberOfConfigurations();
int reloaded = 0;
for (int i = 0; i < ln; i++) {
Configuration conf =
combinedConfiguration.getConfiguration(i);
if (conf instanceof PropertiesConfiguration) {
ManagedReloadingStrategy strat = null;
ReloadingStrategy strategy = ((PropertiesConfiguration)
conf).getReloadingStrategy();
//refresh if managed strategy
if (strategy instanceof ManagedReloadingStrategy) {
((ManagedReloadingStrategy) strategy).refresh();
//reload if file changed strategy
} else if (strategy instanceof
FileChangedReloadingStrategy) {
((PropertiesConfiguration) conf).reload();
}
reloaded++;
}
}
Stack trace of deadlock threads
Name: http-10980-1
State: BLOCKED on
org.apache.commons.configuration.tree.OverrideCombiner@8511bb owned by:
http-10980-6
Total blocked: 154 Total waited: 2
Stack trace:
org.apache.commons.configuration.CombinedConfiguration.invalidate(CombinedConfiguration.java:474)
org.apache.commons.configuration.CombinedConfiguration.configurationChanged(CombinedConfiguration.java:488)
org.apache.commons.configuration.event.EventSource.fireEvent(EventSource.java:249)
org.apache.commons.configuration.AbstractFileConfiguration.fireEvent(AbstractFileConfiguration.java:911)
org.apache.commons.configuration.AbstractFileConfiguration.reload(AbstractFileConfiguration.java:828)
- locked java.lang.Object@127e34c
org.apache.commons.configuration.AbstractFileConfiguration.isEmpty(AbstractFileConfiguration.java:927)
org.apache.commons.configuration.reloading.ManagedReloadingStrategy.refresh(ManagedReloadingStrategy.java:91)
com.gsx.properties.PropertyProviderImpl.reset(PropertyProviderImpl.java:203)
- locked java.lang.Class@109bcda
org.apache.jsp.test.testPropertyProvider_jsp._jspService(testPropertyProvider_jsp.java:60)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
Name: http-10980-6
State: BLOCKED on java.lang.Object@127e34c owned by: http-10980-1
Total blocked: 115 Total waited: 2
Stack trace:
org.apache.commons.configuration.AbstractFileConfiguration.reload(AbstractFileConfiguration.java:814)
org.apache.commons.configuration.AbstractFileConfiguration.getKeys(AbstractFileConfiguration.java:939)
org.apache.commons.configuration.ConfigurationUtils.copy(ConfigurationUtils.java:139)
org.apache.commons.configuration.ConfigurationUtils.convertToHierarchical(ConfigurationUtils.java:199)
org.apache.commons.configuration.CombinedConfiguration
$ConfigData.getTransformedRoot(CombinedConfiguration.java:794)
org.apache.commons.configuration.CombinedConfiguration.constructCombinedNode(CombinedConfiguration.java:653)
org.apache.commons.configuration.CombinedConfiguration.getRootNode(CombinedConfiguration.java:504)
- locked
org.apache.commons.configuration.tree.OverrideCombiner@8511bb
org.apache.commons.configuration.HierarchicalConfiguration.fetchNodeList(HierarchicalConfiguration.java:925)
org.apache.commons.configuration.HierarchicalConfiguration.getProperty(HierarchicalConfiguration.java:327)
org.apache.commons.configuration.CombinedConfiguration.getProperty(CombinedConfiguration.java:578)
org.apache.commons.configuration.AbstractConfiguration.resolveContainerStore(AbstractConfiguration.java:1155)
org.apache.commons.configuration.AbstractConfiguration.getString(AbstractConfiguration.java:1034)
org.apache.jsp.test.testPropertyProvider_jsp._jspService(testPropertyProvider_jsp.java:69)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
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Re: [CONFIGURATION] Deadlock during refresh properties
Posted by Pavel Savara <pa...@intrade.com>.
Hi,
Here is my quick dirty fix,
Because getNodeCombiner() is public method i can grab lock in my code
first before try to do reloading.
synchronized (combinedConfiguration.getNodeCombiner()){
//do the reloading
}
It means locks are grabbed always in the same order so deadlock can't
happen.
Best
Pavel
On Thu, 2008-10-30 at 11:32 +0000, Pavel Savara wrote:
> Hi
> Commons configurations get itself stuck in deadlock when refreshing
> properties using Managed reloading strategy. It seems to me it get stuck
> because of fireEvent in reload method. Another access grabs lock on
> synchronized (getNodeCombiner()) when trying to rebuild but Combined
> configuration is one of the listeners for event es well and it gets
> stuck when processing invalidate. Can anyone suggest quick fix please?
> Relevant information follows. I will create bugreport as well
>
> Thanks
> Pavel
>
> Configuration:
> <configuration>
> <override>
> <system/>
> <properties fileName="gsxweb.properties"
> throwExceptionOnMissing="false"
> config-name="gsxweb" config-optional="false" listDelimiter="|">
> <reloadingStrategy
> config-class="org.apache.commons.configuration.reloading.ManagedReloadingStrategy"/>
> </properties>
> </override>
> </configuration>
>
> Our Reload code:
> int ln = combinedConfiguration.getNumberOfConfigurations();
> int reloaded = 0;
> for (int i = 0; i < ln; i++) {
> Configuration conf =
> combinedConfiguration.getConfiguration(i);
> if (conf instanceof PropertiesConfiguration) {
> ManagedReloadingStrategy strat = null;
> ReloadingStrategy strategy = ((PropertiesConfiguration)
> conf).getReloadingStrategy();
> //refresh if managed strategy
> if (strategy instanceof ManagedReloadingStrategy) {
> ((ManagedReloadingStrategy) strategy).refresh();
> //reload if file changed strategy
> } else if (strategy instanceof
> FileChangedReloadingStrategy) {
> ((PropertiesConfiguration) conf).reload();
> }
> reloaded++;
> }
> }
>
> Stack trace of deadlock threads
> Name: http-10980-1
> State: BLOCKED on
> org.apache.commons.configuration.tree.OverrideCombiner@8511bb owned by:
> http-10980-6
> Total blocked: 154 Total waited: 2
>
> Stack trace:
> org.apache.commons.configuration.CombinedConfiguration.invalidate(CombinedConfiguration.java:474)
> org.apache.commons.configuration.CombinedConfiguration.configurationChanged(CombinedConfiguration.java:488)
> org.apache.commons.configuration.event.EventSource.fireEvent(EventSource.java:249)
> org.apache.commons.configuration.AbstractFileConfiguration.fireEvent(AbstractFileConfiguration.java:911)
> org.apache.commons.configuration.AbstractFileConfiguration.reload(AbstractFileConfiguration.java:828)
> - locked java.lang.Object@127e34c
> org.apache.commons.configuration.AbstractFileConfiguration.isEmpty(AbstractFileConfiguration.java:927)
> org.apache.commons.configuration.reloading.ManagedReloadingStrategy.refresh(ManagedReloadingStrategy.java:91)
> com.gsx.properties.PropertyProviderImpl.reset(PropertyProviderImpl.java:203)
> - locked java.lang.Class@109bcda
> org.apache.jsp.test.testPropertyProvider_jsp._jspService(testPropertyProvider_jsp.java:60)
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
> javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
> org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
> javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
>
>
> Name: http-10980-6
> State: BLOCKED on java.lang.Object@127e34c owned by: http-10980-1
> Total blocked: 115 Total waited: 2
>
> Stack trace:
> org.apache.commons.configuration.AbstractFileConfiguration.reload(AbstractFileConfiguration.java:814)
> org.apache.commons.configuration.AbstractFileConfiguration.getKeys(AbstractFileConfiguration.java:939)
> org.apache.commons.configuration.ConfigurationUtils.copy(ConfigurationUtils.java:139)
> org.apache.commons.configuration.ConfigurationUtils.convertToHierarchical(ConfigurationUtils.java:199)
> org.apache.commons.configuration.CombinedConfiguration
> $ConfigData.getTransformedRoot(CombinedConfiguration.java:794)
> org.apache.commons.configuration.CombinedConfiguration.constructCombinedNode(CombinedConfiguration.java:653)
> org.apache.commons.configuration.CombinedConfiguration.getRootNode(CombinedConfiguration.java:504)
> - locked
> org.apache.commons.configuration.tree.OverrideCombiner@8511bb
> org.apache.commons.configuration.HierarchicalConfiguration.fetchNodeList(HierarchicalConfiguration.java:925)
> org.apache.commons.configuration.HierarchicalConfiguration.getProperty(HierarchicalConfiguration.java:327)
> org.apache.commons.configuration.CombinedConfiguration.getProperty(CombinedConfiguration.java:578)
> org.apache.commons.configuration.AbstractConfiguration.resolveContainerStore(AbstractConfiguration.java:1155)
> org.apache.commons.configuration.AbstractConfiguration.getString(AbstractConfiguration.java:1034)
> org.apache.jsp.test.testPropertyProvider_jsp._jspService(testPropertyProvider_jsp.java:69)
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
> javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
> org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
> javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
>
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> To unsubscribe, e-mail: user-unsubscribe@commons.apache.org
> For additional commands, e-mail: user-help@commons.apache.org
>
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