ACE/ace/Thread_Exit.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file    Thread_Exit.h
   6  *
   7  *  @author Carlos O'Ryan <coryan@uci.edu>
   8  */
   9 //=============================================================================
  10
  11
  12 #ifndef ACE_THREAD_EXIT_H
  13 #define ACE_THREAD_EXIT_H
  14 #include /**/ "ace/pre.h"
  15
  16 #include /**/ "ace/config-all.h"
  17
  18 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  19 # pragma once
  20 #endif /* ACE_LACKS_PRAGMA_ONCE */
  21
  22 #include "ace/Thread_Control.h"
  23
  24 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  25
  26 /**
  27  * @class ACE_Thread_Exit
  28  *
  29  * @brief Keep exit information for a Thread in thread specific storage.
  30  * so that the thread-specific exit hooks will get called no
  31  * matter how the thread exits (e.g., via <ACE_Thread::exit>, C++
  32  * or Win32 exception, "falling off the end" of the thread entry
  33  * point function, etc.).
  34  *
  35  * This clever little helper class is stored in thread-specific
  36  * storage using the <ACE_TSS> wrapper.  When a thread exits the
  37  * <ACE_TSS::cleanup> function deletes this object, thereby
  38  * closing it down gracefully.
  39  */
  40 class ACE_Export ACE_Thread_Exit
  41 {
  42 public:
  43   /// Capture the Thread that will be cleaned up automatically.
  44   ACE_Thread_Exit ();
  45
  46   /// Set the ACE_Thread_Manager.
  47   void thr_mgr (ACE_Thread_Manager *tm);
  48
  49   /// Destructor calls the thread-specific exit hooks when a thread
  50   /// exits.
  51   ~ACE_Thread_Exit ();
  52
  53   /// Singleton access point.
  54   static ACE_Thread_Exit *instance ();
  55
  56   /// Cleanup method, used by the ACE_Object_Manager to destroy the
  57   /// singleton.
  58   static void cleanup (void *instance);
  59
  60   ACE_ALLOC_HOOK_DECLARE;
  61
  62 private:
  63   /// Automatically add/remove the thread from the
  64   /// ACE_Thread_Manager.
  65   ACE_Thread_Control thread_control_;
  66
  67   /**
  68    * Used to detect whether we should create a new instance (or not)
  69    * within the instance method -- we don't trust the instance_ ptr
  70    * because the destructor may have run (if ACE::fini() was called).
  71    * See bug #526.
  72    * We don't follow the singleton pattern due to dependency issues.
  73    */
  74   static bool is_constructed_;
  75 };
  76
  77 /**
  78  * @class ACE_Thread_Exit_Maybe
  79  *
  80  * @brief A version of ACE_Thread_Exit that is created dynamically
  81  * under the hood if the flag is set to TRUE.
  82  *
  83  * Allows the appearance of a "smart pointer", but is not
  84  * always created.
  85  */
  86 class ACE_Export ACE_Thread_Exit_Maybe
  87 {
  88 public:
  89   /// Don't create an ACE_Thread_Exit instance by default.
  90   ACE_Thread_Exit_Maybe (int flag = 0);
  91
  92   /// Destroys the underlying ACE_Thread_Exit instance if it exists.
  93   ~ACE_Thread_Exit_Maybe ();
  94
  95   /// Delegates to underlying instance.
  96   ACE_Thread_Exit * operator -> () const;
  97
  98   /// Returns the underlying instance.
  99   ACE_Thread_Exit * instance () const;
 100
 101 private:
 102   /// Holds the underlying instance.
 103   ACE_Thread_Exit *instance_;
 104 };
 105
 106 ACE_END_VERSIONED_NAMESPACE_DECL
 107
 108 #include /**/ "ace/post.h"
 109 #endif /* ACE_THREAD_EXIT_H */