Notice: A previous bug report has been submitted according to CR 7080954. According to CR 7080954, it should be fixed in jdk7u4 b07 with JAXP 1.4.5 update 1, but per my testing on build b07 and b12 it is not fixed.

This lock is discovered by parsing files(approximately 13KB size) with DOM parsers on T4, using a benchmark called XMLTest. With jdk7u4 b07, com.sun.org.apache.xerces.internal.impl.dv.DTDDVFactory.getInstance() is listed as a top lock class, occupied approximately 57% of total thread time; similar observation in b12.