thread.h

//
// Copyright (c) 2014 Limit Point Systems, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

// Interface for class THREAD

#ifndef THREAD_H
#define THREAD_H

#ifndef SHEAF_DLL_SPEC_H
#include "SheafSystem/sheaf_dll_spec.h"
#endif

#ifdef _PTHREADS
#include "SheafSystem/pthread.h"

#ifndef STD_UNISTD_H
#include "SheafSystem/std_unistd.h"
#endif

#ifndef SINGLY_LINKED_LIST_H
#include "SheafSystem/singly_linked_list.h"
#endif

namespace sheaf
{

class runnable;
  
class SHEAF_DLL_SPEC thread
{

private:

  // data:

  bool                     _is_alive;
  pthread_t                 pthread;
  runnable                *_runnable;
  static singly_linked_list<thread *>  *_thread_list; // $$ISSUE. destroying a thread or querying for is_alive requires
  // a linear search through the list.  For small numbers of threads
  // this is probably ok, but for large numbers a hash table would be
  // better.

  // actions:

  static void   cleanup(thread *This);
  static void  *static_run(thread *This);

public:

  // queries:

  static int       active_count();

  singly_linked_list<thread *> *thread_list();

  bool             invariant() const;

  static bool      is_alive(thread *other);

  // actions:

  static thread *current_thread();

  void           join();

  virtual void   run();

  void           sleep(unsigned int seconds);

  void           start();

  void           stop();

  // constructors:

  thread();

  thread(runnable *xrunnable);

  ~thread();
};

} // namespace sheaf

#endif // _PTHREADS

#endif // ifndef THREAD_H