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Posted to dev@tomcat.apache.org by ma...@apache.org on 2010/02/24 00:03:47 UTC

svn commit: r915573 - in /tomcat/tc6.0.x/trunk: ./ STATUS.txt java/org/apache/catalina/loader/LocalStrings.properties java/org/apache/catalina/loader/WebappClassLoader.java webapps/docs/changelog.xml

Author: markt
Date: Tue Feb 23 23:03:46 2010
New Revision: 915573

URL: http://svn.apache.org/viewvc?rev=915573&view=rev
Log:
More memory leak protection. We can do something about threads started via java.util.Timer

Modified:
    tomcat/tc6.0.x/trunk/   (props changed)
    tomcat/tc6.0.x/trunk/STATUS.txt
    tomcat/tc6.0.x/trunk/java/org/apache/catalina/loader/LocalStrings.properties
    tomcat/tc6.0.x/trunk/java/org/apache/catalina/loader/WebappClassLoader.java
    tomcat/tc6.0.x/trunk/webapps/docs/changelog.xml

Propchange: tomcat/tc6.0.x/trunk/
------------------------------------------------------------------------------
--- svn:mergeinfo (original)
+++ svn:mergeinfo Tue Feb 23 23:03:46 2010
@@ -1,2 +1,2 @@
 /tomcat:883362
-/tomcat/trunk:601180,606992,612607,630314,640888,652744,653247,666232,673796,673820,677910,683969,683982,684001,684081,684234,684269-684270,685177,687503,687645,689402,690781,691392,691805,692748,693378,694992,695053,695311,696780,696782,698012,698227,698236,698613,699427,699634,701355,709294,709811,709816,710063,710066,710125,710205,711126,711600,712461,712467,713953,714002,718360,719119,719124,719602,719626,719628,720046,720069,721040,721286,721708,721886,723404,723738,726052,727303,728032,728768,728947,729057,729567,729569,729571,729681,729809,729815,729934,730250,730590,731651,732859,732863,734734,740675,740684,742677,742697,742714,744160,744238,746321,746384,746425,747834,747863,748344,750258,750291,750921,751286-751287,751289,751295,752323,753039,757335,757774,758249,758365,758596,758616,758664,759074,761601,762868,762929,762936-762937,763166,763183,763193,763228,763262,763298,763302,763325,763599,763611,763654,763681,763706,764985,764997,765662,768335,769979,770716,77
 0809,770876,772872,776921,776924,776935,776945,777464,777466,777576,777625,778379,778523-778524,781528,781779,782145,782791,783316,783696,783724,783756,783762,783766,783863,783934,784453,784602,784614,785381,785688,785768,785859,786468,786487,786490,786496,786667,787627,787770,787985,789389,790405,791041,791184,791194,791224,791243,791326,791328,791789,792740,793372,793757,793882,793981,794082,794673,794822,795043,795152,795210,795457,795466,797168,797425,797596,797607,802727,802940,804462,804544,804734,805153,809131,809603,810916,810977,812125,812137,812432,813001,813013,813866,814180,814708,814876,815972,816252,817442,817822,819339,819361,820110,820132,820874,820954,821397,828196,828201,828210,828225,828759,830378-830379,830999,831106,831774,831785,831828,831850,831860,832214,832218,833121,833545,834047,835036,835336,836405,881396,881412,883130,883134,883146,883165,883177,883362,883565,884341,885038,885231,885241,885260,885901,885991,886019,888072,889363,889606,889716,8901
 39,890265,890349-890350,890417,891185-891187,891583,892198,892341,892415,892464,892555,892812,892814,892817,892843,892887,893321,893493,894580,894586,894805,894831,895013,895045,895057,895191,895392,895703,896370,896384,897380-897381,897776,898126,898256,898468,898527,898555,898558,898718,898836,898906,899284,899348,899420,899653,899769-899770,899783,899788,899792,899916,899918-899919,899935,899949,903916,905020,905151,905722,905728,905735,907311,907513,907538,907825,907864,908721,908759,909636,909875,910442,910471
+/tomcat/trunk:601180,606992,612607,630314,640888,652744,653247,666232,673796,673820,677910,683969,683982,684001,684081,684234,684269-684270,685177,687503,687645,689402,690781,691392,691805,692748,693378,694992,695053,695311,696780,696782,698012,698227,698236,698613,699427,699634,701355,709294,709811,709816,710063,710066,710125,710205,711126,711600,712461,712467,713953,714002,718360,719119,719124,719602,719626,719628,720046,720069,721040,721286,721708,721886,723404,723738,726052,727303,728032,728768,728947,729057,729567,729569,729571,729681,729809,729815,729934,730250,730590,731651,732859,732863,734734,740675,740684,742677,742697,742714,744160,744238,746321,746384,746425,747834,747863,748344,750258,750291,750921,751286-751287,751289,751295,752323,753039,757335,757774,758249,758365,758596,758616,758664,759074,761601,762868,762929,762936-762937,763166,763183,763193,763228,763262,763298,763302,763325,763599,763611,763654,763681,763706,764985,764997,765662,768335,769979,770716,77
 0809,770876,772872,776921,776924,776935,776945,777464,777466,777576,777625,778379,778523-778524,781528,781779,782145,782791,783316,783696,783724,783756,783762,783766,783863,783934,784453,784602,784614,785381,785688,785768,785859,786468,786487,786490,786496,786667,787627,787770,787985,789389,790405,791041,791184,791194,791224,791243,791326,791328,791789,792740,793372,793757,793882,793981,794082,794673,794822,795043,795152,795210,795457,795466,797168,797425,797596,797607,802727,802940,804462,804544,804734,805153,809131,809603,810916,810977,812125,812137,812432,813001,813013,813866,814180,814708,814876,815972,816252,817442,817822,819339,819361,820110,820132,820874,820954,821397,828196,828201,828210,828225,828759,830378-830379,830999,831106,831774,831785,831828,831850,831860,832214,832218,833121,833545,834047,835036,835336,836405,881396,881412,883130,883134,883146,883165,883177,883362,883565,884341,885038,885231,885241,885260,885901,885991,886019,888072,889363,889606,889716,8901
 39,890265,890349-890350,890417,891185-891187,891583,892198,892341,892415,892464,892555,892812,892814,892817,892843,892887,893321,893493,894580,894586,894805,894831,895013,895045,895057,895191,895392,895703,896370,896384,897380-897381,897776,898126,898256,898468,898527,898555,898558,898718,898836,898906,899284,899348,899420,899653,899769-899770,899783,899788,899792,899916,899918-899919,899935,899949,903916,905020,905151,905722,905728,905735,907311,907513,907538,907652,907825,907864,908721,908759,909636,909875,910442,910471

Modified: tomcat/tc6.0.x/trunk/STATUS.txt
URL: http://svn.apache.org/viewvc/tomcat/tc6.0.x/trunk/STATUS.txt?rev=915573&r1=915572&r2=915573&view=diff
==============================================================================
--- tomcat/tc6.0.x/trunk/STATUS.txt (original)
+++ tomcat/tc6.0.x/trunk/STATUS.txt Tue Feb 23 23:03:46 2010
@@ -119,12 +119,6 @@
     http://tools.ietf.org/html/rfc2616
 
 
-* More memory leak protection
-  We can do something about threads started via java.util.Timer
-  http://svn.apache.org/viewvc?rev=907652&view=rev
-  +1: markt, kkolinko, fhanik
-  -1: 
-
 * Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=48109
   Extend try/finally to ensure InputStream is closed
   http://svn.apache.org/viewvc?rev=907819&view=rev

Modified: tomcat/tc6.0.x/trunk/java/org/apache/catalina/loader/LocalStrings.properties
URL: http://svn.apache.org/viewvc/tomcat/tc6.0.x/trunk/java/org/apache/catalina/loader/LocalStrings.properties?rev=915573&r1=915572&r2=915573&view=diff
==============================================================================
--- tomcat/tc6.0.x/trunk/java/org/apache/catalina/loader/LocalStrings.properties (original)
+++ tomcat/tc6.0.x/trunk/java/org/apache/catalina/loader/LocalStrings.properties Tue Feb 23 23:03:46 2010
@@ -39,8 +39,10 @@
 webappClassLoader.clearThreadLocal=A web application created a ThreadLocal with key of type [{0}] (value [{1}]) and a value of type [{2}] (value [{3}]) but failed to remove it when the web application was stopped. To prevent a memory leak, the ThreadLocal has been forcibly removed.
 webappClassLoader.clearThreadLocalFail=Failed to clear ThreadLocal references
 webappClassLoader.stopThreadFail=Failed to terminate thread named [{0}]
+webappClassLoader.stopTimerThreadFail=Failed to terminate TimerThread named [{0}]
 webappClassLoader.validationErrorJarPath=Unable to validate JAR entry with name {0}
 webappClassLoader.warnThread=A web application appears to have started a thread named [{0}] but has failed to stop it. This is very likely to create a memory leak.
+webappClassLoader.warnTimerThread=A web application appears to have started a TimerThread named [{0}] via the java.util.Timer API but has failed to stop it. To prevent a memory leak, the timer (and hence the associated thread) has been forcibly cancelled. 
 webappClassLoader.wrongVersion=(unable to load class {0})
 webappLoader.addRepository=Adding repository {0}
 webappLoader.deploy=Deploying class repositories to work directory {0}

Modified: tomcat/tc6.0.x/trunk/java/org/apache/catalina/loader/WebappClassLoader.java
URL: http://svn.apache.org/viewvc/tomcat/tc6.0.x/trunk/java/org/apache/catalina/loader/WebappClassLoader.java?rev=915573&r1=915572&r2=915573&view=diff
==============================================================================
--- tomcat/tc6.0.x/trunk/java/org/apache/catalina/loader/WebappClassLoader.java (original)
+++ tomcat/tc6.0.x/trunk/java/org/apache/catalina/loader/WebappClassLoader.java Tue Feb 23 23:03:46 2010
@@ -47,6 +47,7 @@
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.TimerTask;
 import java.util.Vector;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.jar.Attributes;
@@ -440,7 +441,9 @@
      * instability. As such, enabling this should be viewed as an option of last
      * resort in a development environment and is not recommended in a
      * production environment. If not specified, the default value of
-     * <code>false</code> will be used. 
+     * <code>false</code> will be used. Note that instances of
+     * java.util.TimerThread will always be terminate since a safe method exists
+     * to do so.
      */
     private boolean clearReferencesStopThreads = false;
 
@@ -1943,6 +1946,13 @@
                         continue;
                     }
                    
+                    // TimerThread is not normally visible
+                    if (thread.getClass().getName().equals(
+                            "java.util.TimerThread")) {
+                        clearReferencesStopTimerThread(thread);
+                        continue;
+                    }
+
                     log.error(sm.getString("webappClassLoader.warnThread",
                             thread.getName()));
                     
@@ -2000,6 +2010,53 @@
     }
 
     
+    private void clearReferencesStopTimerThread(Thread thread) {
+        
+        // Need to get references to:
+        // - newTasksMayBeScheduled field
+        // - queue field
+        // - queue.clear()
+        
+        try {
+            Field newTasksMayBeScheduledField =
+                thread.getClass().getDeclaredField("newTasksMayBeScheduled");
+            newTasksMayBeScheduledField.setAccessible(true);
+            Field queueField = thread.getClass().getDeclaredField("queue");
+            queueField.setAccessible(true);
+    
+            Object queue = queueField.get(thread);
+            
+            Method clearMethod = queue.getClass().getDeclaredMethod("clear");
+            clearMethod.setAccessible(true);
+            
+            synchronized(queue) {
+                newTasksMayBeScheduledField.setBoolean(thread, false);
+                clearMethod.invoke(queue);
+                queue.notify();  // In case queue was already empty.
+            }
+            
+            log.error(sm.getString("webappClassLoader.warnTimerThread",
+                    thread.getName()));
+
+        } catch (NoSuchFieldException e) {
+            log.warn(sm.getString(
+                    "webappClassLoader.stopTimerThreadFail",
+                    thread.getName()), e);
+        } catch (IllegalAccessException e) {
+            log.warn(sm.getString(
+                    "webappClassLoader.stopTimerThreadFail",
+                    thread.getName()), e);
+        } catch (NoSuchMethodException e) {
+            log.warn(sm.getString(
+                    "webappClassLoader.stopTimerThreadFail",
+                    thread.getName()), e);
+        } catch (InvocationTargetException e) {
+            log.warn(sm.getString(
+                    "webappClassLoader.stopTimerThreadFail",
+                    thread.getName()), e);
+        }
+    }
+
     private void clearReferencesThreadLocals() {
         Thread[] threads = getThreads();
 

Modified: tomcat/tc6.0.x/trunk/webapps/docs/changelog.xml
URL: http://svn.apache.org/viewvc/tomcat/tc6.0.x/trunk/webapps/docs/changelog.xml?rev=915573&r1=915572&r2=915573&view=diff
==============================================================================
--- tomcat/tc6.0.x/trunk/webapps/docs/changelog.xml (original)
+++ tomcat/tc6.0.x/trunk/webapps/docs/changelog.xml Tue Feb 23 23:03:46 2010
@@ -86,6 +86,11 @@
         <bug>48726</bug>: Prevent OOME when uploading large WAR files with the
         deployer. Patch provided by adam. (markt)
       </fix>
+      <add>
+        Improve memory leak protection by safely stopping threads started via
+        <code>java.util.Timer</code> that an application starts but fails to
+        stop. (markt)
+      </add>
     </changelog>
   </subsection>
   <subsection name="Jasper">



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