jones-ndb/impl/include/ndb/AsyncNdbContext.h

/*
 Copyright (c) 2013, 2016, Oracle and/or its affiliates. All rights reserved.
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License, version 2.0,
 as published by the Free Software Foundation.

 This program is also distributed with certain software (including
 but not limited to OpenSSL) that is licensed under separate terms,
 as designated in a particular file or component or in included license
 documentation.  The authors of MySQL hereby grant you an additional
 permission to link the program and your derivative works with the
 separately licensed software that they have included with MySQL.

 This program 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 2.0, for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
 */

#include <NdbApi.hpp>
#include "compat_ndb.h"
#include "NdbWaitGroup.hpp"
#include "SharedList.h"
#include "ConcurrentFlag.h"
#include "TransactionImpl.h"
#include "async_common.h"

/* V1 NdbWaitGroup must be created with a fixed maximum size.
   V2 NdbWaitGroup is created with an initial size and will grow as needed.
*/
#ifdef USE_OLD_MULTIWAIT_API
#define WAIT_GROUP_SIZE 1024
#else
#define WAIT_GROUP_SIZE 64
#endif

#ifdef FORCE_UV_LEGACY_COMPAT
#define PTHREAD_RETURN_TYPE void *
#define PTHREAD_RETURN_VAL NULL
#else
#define PTHREAD_RETURN_TYPE void
#define PTHREAD_RETURN_VAL
#endif

extern "C" {
  void ioCompleted(uv_async_t *);
  void ndbTxCompleted(int, NdbTransaction *, void *);
  PTHREAD_RETURN_TYPE run_ndb_listener_thread(void *);
}


class AsyncNdbContext {
public:
  /* Constructor */
  AsyncNdbContext(Ndb_cluster_connection *);

  /* Destructor */
  ~AsyncNdbContext();
  
  /* Methods */
  int executeAsynch(TransactionImpl *, NdbTransaction *,
                    int execType, int abortOption, int forceSend,
                    v8::Handle<v8::Function> execCompleteCallback);

  void shutdown();

  /* Friend functions have C linkage but call the protected methods */
  friend PTHREAD_RETURN_TYPE ::run_ndb_listener_thread(void *);
  friend void ::ioCompleted(uv_async_t *);
  
protected:
  void * runListenerThread();
  void completeCallbacks();

private:
  /* A uv_async_t is a UV object that can signal the main event loop upon
     completion of asynchronous tasks.
     In this design, the UV worker threads send transactions to NDB using 
     executeAsynch(), then adds the Ndb object to a queue of active Ndbs.  
     The NDB Wait Thread waits for all pending transactions to return.
  */
  uv_async_t async_handle;

  /* An AsyncNdbContext serves a single cluster connection
  */
  Ndb_cluster_connection * connection;

  /* The wait group manages the list of NDBs that have been sent.
  */
  NdbWaitGroup * waitgroup;

#ifdef USE_OLD_MULTIWAIT_API
  /* The sent queue holds Ndbs which have just been sent (executeAsynch). 
  */
  SharedList<Ndb> sent_queue;
  
  /* The completed queue holds Ndbs which have returned from execution. 
  */
  SharedList<Ndb> completed_queue;
#endif
  /* Shutdown signal (used only with V2 multiwait but always present)
  */
  ConcurrentFlag shutdown_flag;

  /* Holds the thread ID of the Listener thread
  */
  uv_thread_t listener_thread_id;
};