semaphore

Thread 4255: (state = BLOCKED)
 - sun.misc.Unsafe.park(boolean, long) @bci=0 (Compiled frame; information may be imprecise)
 - java.util.concurrent.locks.LockSupport.park(java.lang.Object) @bci=14, line=186 (Compiled frame)
 - java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt() @bci=1, line=834 (Compiled frame)
 - java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(int) @bci=72, line=994 (Comp$
 - java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(int) @bci=24, line=1303 (Compi$
 - java.util.concurrent.Semaphore.acquire() @bci=5, line=317 (Compiled frame)
 - org.apache.solr.util.AdjustableSemaphore.acquire() @bci=4, line=61 (Compiled frame)
 - org.apache.solr.update.SolrCmdDistributor.submit(org.apache.solr.update.SolrCmdDistributor$Request) @bci=22, li$
 - org.apache.solr.update.SolrCmdDistributor.submit(org.apache.solr.client.solrj.request.UpdateRequestExt, org.apa$
 - org.apache.solr.update.SolrCmdDistributor.flushAdds(int) @bci=217, line=300 (Compiled frame)
 - org.apache.solr.update.SolrCmdDistributor.distribAdd(org.apache.solr.update.AddUpdateCommand, java.util.List, o$
 - org.apache.solr.update.processor.DistributedUpdateProcessor.processAdd(org.apache.solr.update.AddUpdateCommand)$
 - org.apache.solr.update.processor.LogUpdateProcessor.processAdd(org.apache.solr.update.AddUpdateCommand) @bci=61$
 - org.apache.solr.handler.loader.JsonLoader$SingleThreadedJsonLoader.handleAdds() @bci=66, line=392 (Compiled fra$
 - org.apache.solr.handler.loader.JsonLoader$SingleThreadedJsonLoader.processUpdate() @bci=69, line=117 (Interpret$
 - org.apache.solr.handler.loader.JsonLoader$SingleThreadedJsonLoader.load(org.apache.solr.request.SolrQueryReques$
 - org.apache.solr.handler.loader.JsonLoader.load(org.apache.solr.request.SolrQueryRequest, org.apache.solr.respon$
 - org.apache.solr.handler.UpdateRequestHandler$1.load(org.apache.solr.request.SolrQueryRequest, org.apache.solr.r$
 - org.apache.solr.handler.ContentStreamHandlerBase.handleRequestBody(org.apache.solr.request.SolrQueryRequest, or$
 - org.apache.solr.handler.RequestHandlerBase.handleRequest(org.apache.solr.request.SolrQueryRequest, org.apache.s$
 - org.apache.solr.core.SolrCore.preDecorateResponse(org.apache.solr.request.SolrQueryRequest, org.apache.solr.res$
 - org.apache.solr.core.SolrCore.execute(org.apache.solr.request.SolrRequestHandler, org.apache.solr.request.SolrQ$
 - org.apache.solr.servlet.SolrDispatchFilter.execute(javax.servlet.http.HttpServletRequest, org.apache.solr.reque$
 - org.apache.solr.servlet.SolrDispatchFilter.doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse$
 - org.apache.solr.servlet.SolrDispatchFilter.doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse$
 - org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(javax.servlet.ServletRequest, javax.servlet.Servl$
 - org.eclipse.jetty.servlet.ServletHandler.doHandle(java.lang.String, org.eclipse.jetty.server.Request, javax.ser$
 - org.eclipse.jetty.server.handler.ScopedHandler.handle(java.lang.String, org.eclipse.jetty.server.Request, javax$
 - org.eclipse.jetty.security.SecurityHandler.handle(java.lang.String, org.eclipse.jetty.server.Request, javax.ser$
 - org.eclipse.jetty.server.session.SessionHandler.doHandle(java.lang.String, org.eclipse.jetty.server.Request, ja$
 - org.eclipse.jetty.server.handler.ContextHandler.doHandle(java.lang.String, org.eclipse.jetty.server.Request, ja$