PortalImpl.getUniqueElementId() may end up in endless loop, because it isn't thread safe.

• Type: Regression Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 6.2.X EE, 7.0.0 M3
• Fix Version/s: 6.1.X EE, 6.2.2 CE GA3 , 6.2.X EE, 7.0.0 M3
• Component/s: Core Infrastructure
• Labels:
  • QA-NA
  • QA-TP
  • liferay-fixpack-platform-29-6130
  • liferay-fixpack-platform-32-6210
• Branch Version/s:
  6.2.x, 6.1.x
• Backported to Branch:
  Committed
• Story Points: 18
• Fix Priority: 5
• Application Servers:
  Apache Tomcat 7.0
• Git Pull Request: https://github.com/shuyangzhou/liferay-portal/pull/768

Steps to reproduce

1) Add a new page p1
2) Add several Web Content Display portlets to p1
3) Refresh p1 in the browser a couple of times

Observe the CPU usage of the JVM either by JVisualVM or by using the following script.

list_cpu_consumer_threads.sh

#!/bin/sh

pid=`jps -v | grep liferay | awk '{ print $1 }'`

echo "JVM CPU usage:$(ps -o pcpu= -p $pid)%"

nids=`pidstat -t -p $pid | sort -nr -k8 | head -6 | awk '{ print $4 }' | grep -v '^-' | xargs printf '0x%x\n'`

for nid in $nids; do
  echo -e "\nDumping stack trace for native thread ${nid}"
  jstack -l $pid | grep -A 10 "nid\=${nid}" 
done

You should see that there are threads which got into an endless loop in method HashMap.getEntry().

% bash /tmp/list_cpu_consumer_threads.sh
JVM CPU usage: 279%

Dumping stack trace for native thread 0x3c87
"RuntimePageImpl-17" daemon prio=10 tid=0x00007fd120003800 nid=0x3c87 runnable [0x00007fd10f4f0000]
   java.lang.Thread.State: RUNNABLE
	at java.util.HashMap.getEntry(HashMap.java:469)
	at java.util.HashMap.containsKey(HashMap.java:453)
	at java.util.HashSet.contains(HashSet.java:201)
	at com.liferay.portal.util.PortalImpl.getUniqueElementId(PortalImpl.java:5466)
	at com.liferay.portal.util.PortalUtil.getUniqueElementId(PortalUtil.java:1873)
	at com.liferay.taglib.ui.IconTag.getId(IconTag.java:366)
	at com.liferay.taglib.ui.IconTag.setAttributes(IconTag.java:573)
	at com.liferay.taglib.util.IncludeTag.callSetAttributes(IncludeTag.java:175)
	at com.liferay.taglib.util.IncludeTag.doEndTag(IncludeTag.java:72)

Dumping stack trace for native thread 0x3c82
"RuntimePageImpl-13" daemon prio=10 tid=0x00007fd13001e000 nid=0x3c82 runnable [0x00007fd10f8f3000]
   java.lang.Thread.State: RUNNABLE
	at java.util.HashMap.getEntry(HashMap.java:469)
	at java.util.HashMap.containsKey(HashMap.java:453)
	at java.util.HashSet.contains(HashSet.java:201)
	at com.liferay.portal.util.PortalImpl.getUniqueElementId(PortalImpl.java:5466)
	at com.liferay.portal.util.PortalUtil.getUniqueElementId(PortalUtil.java:1873)
	at com.liferay.taglib.ui.IconTag.getId(IconTag.java:366)
	at com.liferay.taglib.ui.IconTag.setAttributes(IconTag.java:573)
	at com.liferay.taglib.util.IncludeTag.callSetAttributes(IncludeTag.java:175)
	at com.liferay.taglib.util.IncludeTag.doEndTag(IncludeTag.java:72)

Dumping stack trace for native thread 0x3c88
"RuntimePageImpl-18" daemon prio=10 tid=0x00007fd13c009800 nid=0x3c88 runnable [0x00007fd10f3ef000]
   java.lang.Thread.State: RUNNABLE
	at java.util.HashMap.getEntry(HashMap.java:469)
	at java.util.HashMap.containsKey(HashMap.java:453)
	at java.util.HashSet.contains(HashSet.java:201)
	at com.liferay.portal.util.PortalImpl.getUniqueElementId(PortalImpl.java:5466)
	at com.liferay.portal.util.PortalUtil.getUniqueElementId(PortalUtil.java:1873)
	at com.liferay.taglib.ui.IconTag.getId(IconTag.java:366)
	at com.liferay.taglib.ui.IconTag.setAttributes(IconTag.java:573)
	at com.liferay.taglib.util.IncludeTag.callSetAttributes(IncludeTag.java:175)
	at com.liferay.taglib.util.IncludeTag.doEndTag(IncludeTag.java:72)
...