Tomcat test from dacapo benchmark could fail with
java.util.ConcurrentModificationException
java.util.ArrayList$Itr.checkForComodification(ArrayList.java:810)
java.util.ArrayList$Itr.next(ArrayList.java:782)
java.util.AbstractCollection.addAll(AbstractCollection.java:336)
java.util.HashSet.<init>(HashSet.java:117)
sun.util.LocaleServiceProviderPool.getAvailableLocales(LocaleServiceProviderPool.java:206)
java.text.DateFormat.getAvailableLocales(DateFormat.java:575)
org.apache.taglibs.standard.tag.common.fmt.FormatDateSupport.doEndTag(Unknown Source)
org.apache.jsp.jsp.jsp2.jspx.basic_jspx._jspx_meth_fmt_005fformatDate_005f0(basic_jspx.java:107)
org.apache.jsp.jsp.jsp2.jspx.basic_jspx.access$0(basic_jspx.java:94)
org.apache.jsp.jsp.jsp2.jspx.basic_jspx$Helper.invoke0(basic_jspx.java:173)
org.apache.jsp.jsp.jsp2.jspx.basic_jspx$Helper.invoke(basic_jspx.java:191)
org.apache.jsp.tag.web.xhtmlbasic_tag.doTag(xhtmlbasic_tag.java:79)
org.apache.jsp.jsp.jsp2.jspx.basic_jspx._jspx_meth_tags_005fxhtmlbasic_005f0(basic_jspx.java:89)
org.apache.jsp.jsp.jsp2.jspx.basic_jspx._jspService(basic_jspx.java:63)
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)


when running with number of threads more than 2.