// -*- C++ -*-

//=============================================================================
/**
 *  @file    Object_Manager_Base.h
 *
 *  @author Douglas C. Schmidt <schmidt@cs.wustl.edu>
 *  @author Jesper S. M|ller<stophph@diku.dk>
 *  @author and a cast of thousands...
 *
 *  Originally in OS.h.
 */
//=============================================================================

#ifndef ACE_OBJECT_MANAGER_BASE_H
#define ACE_OBJECT_MANAGER_BASE_H
#include /**/ "ace/pre.h"

#include /**/ "ace/config-lite.h"

#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */

#include /**/ "ace/ACE_export.h"
#include "ace/Cleanup.h"
#include "ace/os_include/sys/os_types.h"
#include "ace/os_include/os_signal.h"

ACE_BEGIN_VERSIONED_NAMESPACE_DECL

class ACE_Object_Manager;
class ACE_OS_Object_Manager_Manager;
class ACE_TSS_Cleanup;
class ACE_TSS_Emulation;
class ACE_Log_Msg;
class ACE_Thread_Hook;

/**
 * @class ACE_Object_Manager_Base
 *
 * @brief Base class for ACE_Object_Manager(s).
 *
 * Encapsulates the most useful ACE_Object_Manager data structures.
 */
class ACE_Export ACE_Object_Manager_Base
{
protected:
  /// Default constructor.
  ACE_Object_Manager_Base (void);

  /// Destructor.
  virtual ~ACE_Object_Manager_Base (void);

public:
  /**
   * Explicitly initialize.  Returns 0 on success, -1 on failure due
   * to dynamic allocation failure (in which case errno is set to
   * ENOMEM), or 1 if it had already been called.
   */
  virtual int init (void) = 0;

  /**
   * Explicitly destroy.  Returns 0 on success, -1 on failure because
   * the number of fini () calls hasn't reached the number of init ()
   * calls, or 1 if it had already been called.
   */
  virtual int fini (void) = 0;

  enum Object_Manager_State
    {
      OBJ_MAN_UNINITIALIZED = 0,
      OBJ_MAN_INITIALIZING,
      OBJ_MAN_INITIALIZED,
      OBJ_MAN_SHUTTING_DOWN,
      OBJ_MAN_SHUT_DOWN
    };

protected:
  /**
   * Returns 1 before ACE_Object_Manager_Base has been constructed.
   * This flag can be used to determine if the program is constructing
   * static objects.  If no static object spawns any threads, the
   * program will be single-threaded when this flag returns 1.  (Note
   * that the program still might construct some static objects when
   * this flag returns 0, if ACE_HAS_NONSTATIC_OBJECT_MANAGER is not
   * defined.)
   */
  int starting_up_i (void);

  /**
   * Returns 1 after ACE_Object_Manager_Base has been destroyed.  This
   * flag can be used to determine if the program is in the midst of
   * destroying static objects.  (Note that the program might destroy
   * some static objects before this flag can return 1, if
   * ACE_HAS_NONSTATIC_OBJECT_MANAGER is not defined.)
   */
  int shutting_down_i (void);

  /// State of the Object_Manager;
  Object_Manager_State object_manager_state_;

  /**
   * Flag indicating whether the ACE_Object_Manager was dynamically
   * allocated by ACE. (If is was dynamically allocated by the
   * application, then the application is responsible for destroying
   * it.)
   */
  bool dynamically_allocated_;

  /// Link to next Object_Manager, for chaining.
  ACE_Object_Manager_Base *next_;
private:
  // Disallow copying by not implementing the following . . .
  ACE_Object_Manager_Base (const ACE_Object_Manager_Base &);
  ACE_Object_Manager_Base &operator= (const ACE_Object_Manager_Base &);
};

extern "C"
void
ACE_OS_Object_Manager_Internal_Exit_Hook (void);


// @@ This forward declaration should go away.
class ACE_Log_Msg;

class ACE_Export ACE_OS_Object_Manager : public ACE_Object_Manager_Base
{
public:
  /// Explicitly initialize.
  virtual int init (void);

  /// Explicitly destroy.
  virtual int fini (void);

  /**
   * Returns 1 before the ACE_OS_Object_Manager has been
   * constructed.  See <ACE_Object_Manager::starting_up> for more
   * information.
   */
  static int starting_up (void);

  /// Returns 1 after the ACE_OS_Object_Manager has been destroyed.
  /// See <ACE_Object_Manager::shutting_down> for more information.
  static int shutting_down (void);

  /// Unique identifiers for preallocated objects.
  enum Preallocated_Object
    {
# if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0)
      ACE_OS_MONITOR_LOCK,
      ACE_TSS_CLEANUP_LOCK,
      ACE_LOG_MSG_INSTANCE_LOCK,
#   if defined (ACE_HAS_TSS_EMULATION)
      ACE_TSS_KEY_LOCK,
#     if defined (ACE_HAS_THREAD_SPECIFIC_STORAGE)
      ACE_TSS_BASE_LOCK,
#     endif /* ACE_HAS_THREAD_SPECIFIC_STORAGE */
#   endif /* ACE_HAS_TSS_EMULATION */
# else
      // Without ACE_MT_SAFE, There are no preallocated objects.  Make
      // sure that the preallocated_array size is at least one by
      // declaring this dummy . . .
      ACE_OS_EMPTY_PREALLOCATED_OBJECT,
# endif /* ACE_MT_SAFE */

      /// This enum value must be last!
      ACE_OS_PREALLOCATED_OBJECTS
    };

  /// Accesses a default signal set used, for example, in
  /// ACE_Sig_Guard methods.
  static sigset_t *default_mask (void);

  /// Returns the current thread hook for the process.
  static ACE_Thread_Hook *thread_hook (void);

  /// Returns the existing thread hook and assign a <new_thread_hook>.
  static ACE_Thread_Hook *thread_hook (ACE_Thread_Hook *new_thread_hook);

#if defined (ACE_HAS_WIN32_STRUCTURAL_EXCEPTIONS)
  /// Get/Set TSS exception action.
  static ACE_SEH_EXCEPT_HANDLER seh_except_selector (void);
  static ACE_SEH_EXCEPT_HANDLER seh_except_selector (ACE_SEH_EXCEPT_HANDLER);

  static ACE_SEH_EXCEPT_HANDLER seh_except_handler (void);
  static ACE_SEH_EXCEPT_HANDLER seh_except_handler (ACE_SEH_EXCEPT_HANDLER);
#endif /* ACE_HAS_WIN32_STRUCTURAL_EXCEPTIONS */

public:
  // = Applications shouldn't use these so they're hidden here.

  // They're public so that the ACE_Object_Manager can be
  // constructed/destructed in <main> with
  // <ACE_HAS_NONSTATIC_OBJECT_MANAGER>.
  /// Constructor.
  ACE_OS_Object_Manager (void);

  /// Destructor.
  ~ACE_OS_Object_Manager (void);

  /// Accessor to singleton instance.
  static ACE_OS_Object_Manager *instance (void);

  /// For <ACE_OS::atexit> support.
  int at_exit (ACE_EXIT_HOOK func, const char* name = 0);

//private:
  /// Singleton instance pointer.
  static ACE_OS_Object_Manager *instance_;

  /// Table of preallocated objects.
  static void *preallocated_object[ACE_OS_PREALLOCATED_OBJECTS];

  /// Default signal set used, for example, in ACE_Sig_Guard.
  sigset_t *default_mask_;

  /// Thread hook that's used by this process.
  ACE_Thread_Hook *thread_hook_;

  /// For at_exit support.
  ACE_OS_Exit_Info exit_info_;

#if defined (ACE_HAS_WIN32_STRUCTURAL_EXCEPTIONS)
  /// These handlers determine how a thread handles win32 structured
  /// exception.
  ACE_SEH_EXCEPT_HANDLER seh_except_selector_;
  ACE_SEH_EXCEPT_HANDLER seh_except_handler_;
#endif /* ACE_HAS_WIN32_STRUCTURAL_EXCEPTIONS */

  /// For use by init () and fini (), to consolidate error reporting.
  static void print_error_message (unsigned int line_number, const ACE_TCHAR *message);

  /// This class is for internal use by ACE_OS, etc., only.
  friend class ACE_Object_Manager;
  friend class ACE_OS_Object_Manager_Manager;
  friend class ACE_TSS_Cleanup;
  friend class ACE_TSS_Emulation;
  friend class ACE_Log_Msg;
  friend void ACE_OS_Object_Manager_Internal_Exit_Hook ();
};

ACE_END_VERSIONED_NAMESPACE_DECL

#include /**/ "ace/post.h"
#endif /* ACE_OBJECT_MANAGER_BASE_H */
