When we write data in BindingDOMDataBroker, it blocked in JavassistUtils

BLOCKED here:

13994 "qtp268948981-993" prio=10 tid=0x00007f40a4e86800 nid=0x66ce waiting for monitor entry [0x00007f40677d3000]
13995 java.lang.Thread.State: BLOCKED (on object monitor)
13996 at org.opendaylight.yangtools.sal.binding.generator.util.JavassistUtils.appendClassLoaderIfMissing(JavassistUtils.java:197)
13997 - waiting to lock <0x00000006e1d5e518> (a org.opendaylight.yangtools.sal.binding.generator.util.JavassistUtils)
13998 at org.opendaylight.yangtools.binding.data.codec.gen.impl.AbstractStreamWriterGenerator.generateEmitterSource(AbstractStreamWriterGenerator.java:162)
13999 at org.opendaylight.yangtools.binding.data.codec.gen.impl.AbstractStreamWriterGenerator.access$200(AbstractStreamWriterGenerator.java:46)
14000 at org.opendaylight.yangtools.binding.data.codec.gen.impl.AbstractStreamWriterGenerator$SerializerImplementationLoader.generateSerializer(AbstractStreamWriterGenerat or.java:135)
14001 at org.opendaylight.yangtools.binding.data.codec.gen.impl.AbstractStreamWriterGenerator$SerializerImplementationLoader.load(AbstractStreamWriterGenerator.java:124)
14002 at org.opendaylight.yangtools.binding.data.codec.gen.impl.AbstractStreamWriterGenerator$SerializerImplementationLoader.load(AbstractStreamWriterGenerator.java:102)
14003 at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3527)
14004 at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2319)
14005 at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2282)
14006 - locked <0x00000006ee294b38> (a com.google.common.cache.LocalCache$WeakEntry)
14007 at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2197)
14008 at com.google.common.cache.LocalCache.get(LocalCache.java:3937)
14009 at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3941)
14010 at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4824)
14011 at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4830)
14012 at org.opendaylight.yangtools.binding.data.codec.gen.impl.AbstractStreamWriterGenerator.getSerializer(AbstractStreamWriterGenerator.java:89)
14013 at org.opendaylight.yangtools.binding.data.codec.impl.BindingNormalizedNodeCodecRegistry$GeneratorLoader.load(BindingNormalizedNodeCodecRegistry.java:276)
14014 at org.opendaylight.yangtools.binding.data.codec.impl.BindingNormalizedNodeCodecRegistry$GeneratorLoader.load(BindingNormalizedNodeCodecRegistry.java:273)
14015 at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3527)
14016 at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2319)
14017 at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2282)
14018 - locked <0x00000006ee27a820> (a com.google.common.cache.LocalCache$WeakEntry)
14019 at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2197)
14020 at com.google.common.cache.LocalCache.get(LocalCache.java:3937)
14021 at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3941)
14022 at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4824)
14023 at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4830)
14024 at org.opendaylight.yangtools.binding.data.codec.impl.BindingNormalizedNodeCodecRegistry.getSerializer(BindingNormalizedNodeCodecRegistry.java:72)
14025 at org.opendaylight.yangtools.binding.data.codec.impl.BindingNormalizedNodeCodecRegistry.toNormalizedNode(BindingNormalizedNodeCodecRegistry.java:106)
14026 at org.opendaylight.controller.md.sal.binding.impl.BindingToNormalizedNodeCodec.toNormalizedNode(BindingToNormalizedNodeCodec.java:133)
14027 at org.opendaylight.controller.md.sal.binding.impl.AbstractWriteTransaction.put(AbstractWriteTransaction.java:39)
14029 - locked <0x00000006e54219f8> (a org.opendaylight.controller.md.sal.binding.impl.BindingDOMDataBrokerAdapter)

LOCKED here:

qtp268948981-1012" prio=10 tid=0x00007f40ac013800 nid=0x6f90 waiting on condition [0x00007f40663bf000]
35610 java.lang.Thread.State: WAITING (parking)
35611 at sun.misc.Unsafe.park(Native Method)
35612 - parking to wait for <0x00000006ede2b428> (a com.google.common.util.concurrent.AbstractFuture$Sync)
35613 at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
35614 at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834)
35615 at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:994)
35616 at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1303)
35617 at com.google.common.util.concurrent.AbstractFuture$Sync.get(AbstractFuture.java:285)
35618 at com.google.common.util.concurrent.AbstractFuture.get(AbstractFuture.java:116)
35619 at com.google.common.util.concurrent.Uninterruptibles.getUninterruptibly(Uninterruptibles.java:137)
35620 at com.google.common.cache.LocalCache$LoadingValueReference.waitForValue(LocalCache.java:3557)
35621 at com.google.common.cache.LocalCache$Segment.waitForLoadingValue(LocalCache.java:2302)
35622 at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2191)
35623 at com.google.common.cache.LocalCache.get(LocalCache.java:3937)
35624 at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3941)
35625 at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4824)
35626 at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4830)
35627 at org.opendaylight.yangtools.binding.data.codec.gen.impl.AbstractStreamWriterGenerator.loadSerializerFor(AbstractStreamWriterGenerator.java:99)
35628 at org.opendaylight.yangtools.binding.data.codec.gen.impl.DataObjectSerializerSource.staticInvokeEmitter(DataObjectSerializerSource.java:139)
35629 at org.opendaylight.yangtools.binding.data.codec.gen.impl.DataNodeContainerSerializerSource.emitList(DataNodeContainerSerializerSource.java:211)
35630 at org.opendaylight.yangtools.binding.data.codec.gen.impl.DataNodeContainerSerializerSource.emitChildInner(DataNodeContainerSerializerSource.java:176)
35631 at org.opendaylight.yangtools.binding.data.codec.gen.impl.DataNodeContainerSerializerSource.emitChild(DataNodeContainerSerializerSource.java:158)
35632 at org.opendaylight.yangtools.binding.data.codec.gen.impl.DataNodeContainerSerializerSource.emitBody(DataNodeContainerSerializerSource.java:148)
35633 at org.opendaylight.yangtools.binding.data.codec.gen.impl.DataNodeContainerSerializerSource.getSerializerBody(DataNodeContainerSerializerSource.java:78)
35634 at org.opendaylight.yangtools.binding.data.codec.gen.impl.AbstractStreamWriterGenerator$1$1.get(AbstractStreamWriterGenerator.java:202)
35635 at org.opendaylight.yangtools.binding.data.codec.gen.impl.AbstractStreamWriterGenerator$1$1.get(AbstractStreamWriterGenerator.java:199)
35636 at org.opendaylight.yangtools.util.ClassLoaderUtils.withClassLoader(ClassLoaderUtils.java:53)
35637 at org.opendaylight.yangtools.binding.data.codec.gen.impl.AbstractStreamWriterGenerator$1.customizeClass(AbstractStreamWriterGenerator.java:199)
35638 at org.opendaylight.yangtools.sal.binding.generator.util.JavassistUtils.instantiatePrototype(JavassistUtils.java:131)
35639 - locked <0x00000006e1d5e518> (a org.opendaylight.yangtools.sal.binding.generator.util.JavassistUtils)