TAO/tao/Wait_On_LF_No_Upcall.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file    Wait_On_LF_No_Upcall.h
   6  *
   7  *  @author  Chris Cleeland <cleeland@ociweb.com>
   8  */
   9 //=============================================================================
  10
  11
  12 #ifndef TAO_WAIT_ON_LF_NO_UPCALL_H
  13 #define TAO_WAIT_ON_LF_NO_UPCALL_H
  14
  15 #include /**/ "ace/pre.h"
  16
  17 #include "tao/Wait_On_Leader_Follower.h"
  18
  19 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  20 # pragma once
  21 #endif /* ACE_LACKS_PRAGMA_ONCE */
  22
  23 TAO_BEGIN_VERSIONED_NAMESPACE_DECL
  24
  25 namespace TAO
  26 {
  27   /**
  28    * @class TAO_Wait_On_LF_No_Upcall
  29    *
  30    * @brief Wait according to the Leader-Follower model (like
  31    * TAO_Wait_On_Leader_Follower), but do not allow nested upcalls.
  32    *
  33    * This implementation sets a thread-specific flag on entering wait()
  34    * that indicates that the thread is unavailable to service upcalls.
  35    * Connection handler that are acting in a server role cooperate by
  36    * checking this flag in their handle_input, and returning if they're
  37    * in a thread that is currently suspending upcalls. The flag gets
  38    * reset once the reply is received.
  39    */
  40   class Wait_On_LF_No_Upcall : public TAO_Wait_On_Leader_Follower
  41   {
  42   public:
  43      /// Constructor.
  44     explicit Wait_On_LF_No_Upcall (TAO_Transport *t);
  45
  46     /// Destructor.
  47     ~Wait_On_LF_No_Upcall () override = default;
  48
  49     /*! @copydoc TAO_Wait_Strategy::wait() */
  50     int wait (ACE_Time_Value *max_wait_time, TAO_Synch_Reply_Dispatcher &rd) override;
  51
  52     /*! @copydoc TAO_Wait_Strategy::can_process_upcalls() */
  53     bool can_process_upcalls () const override;
  54
  55     /*! @copydoc TAO_Wait_Strategy::defer_upcall() */
  56     int defer_upcall (ACE_Event_Handler*) override;
  57   };
  58 }
  59
  60 TAO_END_VERSIONED_NAMESPACE_DECL
  61
  62 #include /**/ "ace/post.h"
  63
  64 #endif /* TAO_WAIT_ON_LF_NO_UPCALL_H */