src/hotspot/share/jfr/recorder/service/jfrRecorderThreadLoop.cpp

/*
 * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "jfr/recorder/jfrRecorder.hpp"
#include "jfr/recorder/service/jfrPostBox.hpp"
#include "jfr/recorder/service/jfrRecorderService.hpp"
#include "jfr/recorder/service/jfrRecorderThread.hpp"
#include "logging/log.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/thread.inline.hpp"

//
// Entry point for "JFR Recorder Thread" message loop.
// The recorder thread executes service requests collected from the message system.
//
void recorderthread_entry(JavaThread* thread, Thread* unused) {
  assert(thread != NULL, "invariant");
  #define START (msgs & (MSGBIT(MSG_START)))
  #define SHUTDOWN (msgs & MSGBIT(MSG_SHUTDOWN))
  #define ROTATE (msgs & (MSGBIT(MSG_ROTATE)|MSGBIT(MSG_STOP)))
  #define FLUSHPOINT (msgs & (MSGBIT(MSG_FLUSHPOINT)))
  #define PROCESS_FULL_BUFFERS (msgs & (MSGBIT(MSG_ROTATE)|MSGBIT(MSG_STOP)|MSGBIT(MSG_FULLBUFFER)))
  #define SCAVENGE (msgs & (MSGBIT(MSG_DEADBUFFER)))

  JfrPostBox& post_box = JfrRecorderThread::post_box();
  log_debug(jfr, system)("Recorder thread STARTED");

  {
    bool done = false;
    int msgs = 0;
    JfrRecorderService service;
    MutexLocker msg_lock(JfrMsg_lock);

    // JFR MESSAGE LOOP PROCESSING - BEGIN
    while (!done) {
      if (post_box.is_empty()) {
        JfrMsg_lock->wait();
      }
      msgs = post_box.collect();
      JfrMsg_lock->unlock();
      if (PROCESS_FULL_BUFFERS) {
        service.process_full_buffers();
      }
      if (SCAVENGE) {
        service.scavenge();
      }
      // Check amount of data written to chunk already
      // if it warrants asking for a new chunk
      service.evaluate_chunk_size_for_rotation();
      if (START) {
        service.start();
      } else if (ROTATE) {
        service.rotate(msgs);
      } else if (FLUSHPOINT) {
        service.flushpoint();
      }
      JfrMsg_lock->lock();
      post_box.notify_waiters();
      if (SHUTDOWN) {
        log_debug(jfr, system)("Request to STOP recorder");
        done = true;
      }
    } // JFR MESSAGE LOOP PROCESSING - END

  } // JfrMsg_lock scope

  assert(!JfrMsg_lock->owned_by_self(), "invariant");
  post_box.notify_collection_stop();
  JfrRecorder::on_recorder_thread_exit();

  #undef START
  #undef SHUTDOWN
  #undef ROTATE
  #undef FLUSHPOINT
  #undef PROCESS_FULL_BUFFERS
  #undef SCAVENGE
}