# ACE_Event_Handler_T< T > Class Template Reference

Enable a class that doesn't inherit from the ACE_Event_Handler to be incorporated into the ACE_Reactor framework. Thanks to Greg Lavender (g.lavender@isode.com) for sharing this idea. More...

`#include <Event_Handler_T.h>`

Inheritance diagram for ACE_Event_Handler_T< T >:

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Collaboration diagram for ACE_Event_Handler_T< T >:

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List of all members.

## Public Types

typedef ACE_HANDLE(T::* | GET_HANDLE )(void) const
typedef void(T::* | SET_HANDLE )(ACE_HANDLE)
typedef int(T::* | IO_HANDLER )(ACE_HANDLE)
| Handle I/O events.
typedef int(T::* | TO_HANDLER )(const ACE_Time_Value &, const void *)
| Handle timeout events.
typedef int(T::* | CL_HANDLER )(ACE_HANDLE, ACE_Reactor_Mask)
| Handle close events.
typedef int(T::* | SIG_HANDLER )(int, siginfo_t *, ucontext_t *)
| = Initialization and termination methods.

## Public Member Functions

| ACE_Event_Handler_T (T *op_handler, int delete_handler, GET_HANDLE get_handle=0, IO_HANDLER input=0, CL_HANDLER close=0, SIG_HANDLER sig=0, TO_HANDLER timeout=0, IO_HANDLER output=0, SET_HANDLE set_handle=0, IO_HANDLER except=0)
| Initialize the op_handler.
| ~ACE_Event_Handler_T (void)
| Close down and delete the <op_handler>.
virtual ACE_HANDLE | get_handle (void) const
| Get the I/O handle.
virtual void | set_handle (ACE_HANDLE)
| Set the I/O handle.
virtual int | handle_input (ACE_HANDLE fd=ACE_INVALID_HANDLE)
| Called when input events occur (e.g., connection or data).
virtual int | handle_output (ACE_HANDLE fd=ACE_INVALID_HANDLE)
virtual int | handle_exception (ACE_HANDLE fd=ACE_INVALID_HANDLE)
| Called when an exceptional events occur (e.g., SIGURG).
virtual int | handle_timeout (const ACE_Time_Value &tv, const void *arg=0)
virtual int | handle_close (ACE_HANDLE fd, ACE_Reactor_Mask close_mask)
virtual int | handle_signal (int signum, siginfo_t *=0, ucontext_t *=0)
T * | op_handler (void)
void | op_handler (T *)
GET_HANDLE | handle_get (void)
void | handle_get (GET_HANDLE)
SET_HANDLE | handle_set (void)
void | handle_set (SET_HANDLE)
IO_HANDLER | input_handler (void)
void | input_handler (IO_HANDLER)
IO_HANDLER | output_handler (void)
void | output_handler (IO_HANDLER)
IO_HANDLER | except_handler (void)
void | except_handler (IO_HANDLER)
TO_HANDLER | to_handler (void)
void | to_handler (TO_HANDLER)
CL_HANDLER | cl_handler (void)
void | cl_handler (CL_HANDLER)
SIG_HANDLER | sig_handler (void)
void | sig_handler (SIG_HANDLER)
void | dump (void) const
| Dump the state of an object.

## Public Attributes

| ACE_ALLOC_HOOK_DECLARE
| Declare the dynamic allocation hooks.

## Protected Attributes

T * | op_handler_
| Pointer to the object that handles all the delegated operations.
IO_HANDLER | input_handler_
IO_HANDLER | output_handler_
IO_HANDLER | except_handler_
TO_HANDLER | to_handler_
| Handle timeout events.
CL_HANDLER | cl_handler_
| Handle close events.
SIG_HANDLER | sig_handler_
| Handle signal events.
int | delete_handler_
SET_HANDLE | set_handle_
GET_HANDLE | get_handle_

## Detailed Description

### template<class T>
class ACE_Event_Handler_T< T >

Enable a class that doesn't inherit from the ACE_Event_Handler to be incorporated into the ACE_Reactor framework. Thanks to Greg Lavender (g.lavender@isode.com) for sharing this idea.

It is sometimes the case that an application has a hierarchy of operation dispatcher classes that have their own inheritance hierarchy but also would like to integrate with the ACE_Reactor. Rather than adopt a "mixin" approach, it is often cleaner to define a template as a subclass of ACE_Event_Handler and paramterize it with an operation dispatcher type. When constructing an instantiation of the ACE_Event_Handler_T object, a set of pointers to member functions must be provided so that when one of the handle_* methods is called by the ACE_Reactor, the appropriate method is called on the underlying operations object. This is done since in some cases it is useful to map any event that happens to the same method on an object. The ACE_Event_Handler_T template is instantiated by an operations object and registered with the ACE_Reactor, and it then calls the appropriate op_handler. So, it's basically just another level of indirection in event dispatching. The coupling betweent the ultimate handler of the event and the ACE_Event_Handler class is relaxed a bit by have this intermediate <op_handler_> object of type <t> around. The client object can then dynamically change the bindings for the various handlers so that during the life of one of the operation objects, it can change how it wants events to be handled. It just instantiates a new instance of the template with different bindings and reregisters this new object with the ACE_Reactor.

## Member Typedef Documentation

template<class T>
typedef int(T::* ACE_Event_Handler_T< T >::CL_HANDLER)(ACE_HANDLE, ACE_Reactor_Mask)

| Handle close events.

template<class T>
typedef ACE_HANDLE(T::* ACE_Event_Handler_T< T >::GET_HANDLE)(void) const

template<class T>
typedef int(T::* ACE_Event_Handler_T< T >::IO_HANDLER)(ACE_HANDLE)

| Handle I/O events.

template<class T>
typedef void(T::* ACE_Event_Handler_T< T >::SET_HANDLE)(ACE_HANDLE)

template<class T>
typedef int(T::* ACE_Event_Handler_T< T >::SIG_HANDLER)(int, siginfo_t *, ucontext_t *)

| = Initialization and termination methods.

template<class T>
typedef int(T::* ACE_Event_Handler_T< T >::TO_HANDLER)(const ACE_Time_Value &, const void *)

| Handle timeout events.

## Constructor & Destructor Documentation

template<class T>
ACE_Event_Handler_T< T >::ACE_Event_Handler_T | ( | T * | op_handler,
|  | int | delete_handler,
|  | GET_HANDLE | get_handle = `0`,
|  | IO_HANDLER | input = `0`,
|  | CL_HANDLER | close = `0`,
|  | SIG_HANDLER | sig = `0`,
|  | TO_HANDLER | timeout = `0`,
|  | IO_HANDLER | output = `0`,
|  | SET_HANDLE | set_handle = `0`,
|  | IO_HANDLER | except = `0`
| ) |

| Initialize the op_handler.

template<class T>
ACE_Event_Handler_T< T >::~ACE_Event_Handler_T | ( | void |  | ) |

| Close down and delete the <op_handler>.

## Member Function Documentation

template<class T>
void ACE_Event_Handler_T< T >::cl_handler | ( | CL_HANDLER |  | ) |

template<class T>
ACE_INLINE ACE_TYPENAME ACE_Event_Handler_T< T >::CL_HANDLER ACE_Event_Handler_T< T >::cl_handler | ( | void |  | ) |

template<class T>
ACE_BEGIN_VERSIONED_NAMESPACE_DECL void ACE_Event_Handler_T< T >::dump | ( | void |  | ) | const

| Dump the state of an object.

template<class T>
void ACE_Event_Handler_T< T >::except_handler | ( | IO_HANDLER |  | ) |

template<class T>
ACE_INLINE ACE_TYPENAME ACE_Event_Handler_T< T >::IO_HANDLER ACE_Event_Handler_T< T >::except_handler | ( | void |  | ) |

template<class T>
ACE_HANDLE ACE_Event_Handler_T< T >::get_handle | ( | void |  | ) | const`[virtual]`

| Get the I/O handle. Reimplemented from ACE_Event_Handler.

template<class T>
int ACE_Event_Handler_T< T >::handle_close | ( | ACE_HANDLE | fd,
|  | ACE_Reactor_Mask | close_mask
| ) | `[virtual]`

| Called when a <handle_*()> method returns -1 or when the <remove_handler> method is called on an ACE_Reactor. The <close_mask> indicates which event has triggered the <handle_close> method callback on a particular <handle>. Reimplemented from ACE_Event_Handler.

template<class T>
int ACE_Event_Handler_T< T >::handle_exception | ( | ACE_HANDLE | fd = `ACE_INVALID_HANDLE` | ) | `[virtual]`

| Called when an exceptional events occur (e.g., SIGURG). Reimplemented from ACE_Event_Handler.

template<class T>
void ACE_Event_Handler_T< T >::handle_get | ( | GET_HANDLE |  | ) |

template<class T>
ACE_INLINE ACE_TYPENAME ACE_Event_Handler_T< T >::GET_HANDLE ACE_Event_Handler_T< T >::handle_get | ( | void |  | ) |

template<class T>
int ACE_Event_Handler_T< T >::handle_input | ( | ACE_HANDLE | fd = `ACE_INVALID_HANDLE` | ) | `[virtual]`

| Called when input events occur (e.g., connection or data). Reimplemented from ACE_Event_Handler.

template<class T>
int ACE_Event_Handler_T< T >::handle_output | ( | ACE_HANDLE | fd = `ACE_INVALID_HANDLE` | ) | `[virtual]`

| Called when output events are possible (e.g., when flow control abates or non-blocking connection completes). Reimplemented from ACE_Event_Handler.

template<class T>
void ACE_Event_Handler_T< T >::handle_set | ( | SET_HANDLE |  | ) |

template<class T>
ACE_INLINE ACE_TYPENAME ACE_Event_Handler_T< T >::SET_HANDLE ACE_Event_Handler_T< T >::handle_set | ( | void |  | ) |

template<class T>
int ACE_Event_Handler_T< T >::handle_signal | ( | int | signum,
|  | siginfo_t * | = `0`,
|  | ucontext_t * | = `0`
| ) | `[virtual]`

| Called when object is signaled by OS (either via UNIX signals or when a Win32 object becomes signaled). Reimplemented from ACE_Event_Handler.

template<class T>
int ACE_Event_Handler_T< T >::handle_timeout | ( | const ACE_Time_Value & | tv,
|  | const void * | arg = `0`
| ) | `[virtual]`

| Called when timer expires. <current_time> represents the current time that the <event_handler> was selected for timeout dispatching and <act> is the asynchronous completion token that was passed in when <schedule_timer> was invoked. Reimplemented from ACE_Event_Handler.

template<class T>
void ACE_Event_Handler_T< T >::input_handler | ( | IO_HANDLER |  | ) |

template<class T>
ACE_INLINE ACE_TYPENAME ACE_Event_Handler_T< T >::IO_HANDLER ACE_Event_Handler_T< T >::input_handler | ( | void |  | ) |

template<class T>
ACE_BEGIN_VERSIONED_NAMESPACE_DECL ACE_INLINE void ACE_Event_Handler_T< T >::op_handler | ( | T * |  | ) |

template<class T>
ACE_INLINE T * ACE_Event_Handler_T< T >::op_handler | ( | void |  | ) |

template<class T>
void ACE_Event_Handler_T< T >::output_handler | ( | IO_HANDLER |  | ) |

template<class T>
ACE_INLINE ACE_TYPENAME ACE_Event_Handler_T< T >::IO_HANDLER ACE_Event_Handler_T< T >::output_handler | ( | void |  | ) |

template<class T>
void ACE_Event_Handler_T< T >::set_handle | ( | ACE_HANDLE |  | ) | `[virtual]`

| Set the I/O handle. Reimplemented from ACE_Event_Handler.

template<class T>
void ACE_Event_Handler_T< T >::sig_handler | ( | SIG_HANDLER |  | ) |

template<class T>
ACE_INLINE ACE_TYPENAME ACE_Event_Handler_T< T >::SIG_HANDLER ACE_Event_Handler_T< T >::sig_handler | ( | void |  | ) |

template<class T>
void ACE_Event_Handler_T< T >::to_handler | ( | TO_HANDLER |  | ) |

template<class T>
ACE_INLINE ACE_TYPENAME ACE_Event_Handler_T< T >::TO_HANDLER ACE_Event_Handler_T< T >::to_handler | ( | void |  | ) |

## Member Data Documentation

template<class T>
ACE_Event_Handler_T< T >::ACE_ALLOC_HOOK_DECLARE

| Declare the dynamic allocation hooks.

template<class T>
CL_HANDLER ACE_Event_Handler_T< T >::cl_handler_ `[protected]`

| Handle close events.

template<class T>
int ACE_Event_Handler_T< T >::delete_handler_ `[protected]`

| Keeps track of whether we need to delete the handler in the destructor.

template<class T>
IO_HANDLER ACE_Event_Handler_T< T >::except_handler_ `[protected]`

template<class T>
GET_HANDLE ACE_Event_Handler_T< T >::get_handle_ `[protected]`

template<class T>
IO_HANDLER ACE_Event_Handler_T< T >::input_handler_ `[protected]`

template<class T>
T* ACE_Event_Handler_T< T >::op_handler_ `[protected]`

| Pointer to the object that handles all the delegated operations.

template<class T>
IO_HANDLER ACE_Event_Handler_T< T >::output_handler_ `[protected]`

template<class T>
SET_HANDLE ACE_Event_Handler_T< T >::set_handle_ `[protected]`

template<class T>
SIG_HANDLER ACE_Event_Handler_T< T >::sig_handler_ `[protected]`

| Handle signal events.

template<class T>
TO_HANDLER ACE_Event_Handler_T< T >::to_handler_ `[protected]`

| Handle timeout events.

The documentation for this class was generated from the following files:

- Event_Handler_T.h
- Event_Handler_T.cpp
- Event_Handler_T.inl