ACE_Reactor类学习
ACE_Reactor : 这是一个事件监听分派中心， 通过ACE_Reactor注册需要监控的事件，当事件发生时，ACE_Reactor就会自动调用注册时指定的控制程序进行处理。转：ACE Reactor 框架简化了事件驱动程序的开发，而事件驱动是许多网络化应用的特征。该框架实现Reactor模式，允许事件驱动的应用对源自许多不同事件源的事件作出反应，如I/O句柄，定时器，以及信号。应用重新定义框架所定义的挂钩方法，对其进行分派来处理事件。一、ACE Reactor 框架的责任：1、检测来自各种事件源的事件的发生。2、将事件多路分离给其预先登记的事件处理器。3、分派给处理器所定义的挂钩方法，从而以一种应用定义的方式处理这些事件。源代码
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[*]// $Id: Reactor.cpp 91368 2010-08-16 13:03:34Z mhengstmengel $
[*]
[*]#include "ace/Reactor.h"
[*]
[*]#if !defined (ACE_LACKS_ACE_SVCCONF)
[*]#include "ace/Service_Config.h"
[*]#endif /* !ACE_LACKS_ACE_SVCCONF */
[*]
[*]/*
[*] * Hook to specialize the includes directly with the concrete
[*] * Reactor type, e.g., select, thread pool reactor
[*] * known at compile time. This hook results in all the
[*] * #defines being commented
[*] * out and the concrete header file directly included.
[*] */
[*]//@@ REACTOR_SPL_COMMENT_INCLUDE_START_HOOK
[*]// Only include the headers needed to compile.
[*]#if !defined (ACE_WIN32) \
[*] || !defined (ACE_HAS_WINSOCK2) || (ACE_HAS_WINSOCK2 == 0) \
[*] || defined (ACE_USE_SELECT_REACTOR_FOR_REACTOR_IMPL) \
[*] || defined (ACE_USE_TP_REACTOR_FOR_REACTOR_IMPL) \
[*] || defined (ACE_USE_DEV_POLL_REACTOR_FOR_REACTOR_IMPL)
[*]#if defined (ACE_USE_TP_REACTOR_FOR_REACTOR_IMPL)
[*]# include "ace/TP_Reactor.h"
[*]#else
[*]# if defined (ACE_USE_DEV_POLL_REACTOR_FOR_REACTOR_IMPL)
[*]# include "ace/Dev_Poll_Reactor.h"
[*]# else
[*]# include "ace/Select_Reactor.h"
[*]# endif /* ACE_USE_DEV_POLL_REACTOR_FOR_REACTOR_IMPL */
[*]#endif /* ACE_USE_TP_REACTOR_FOR_REACTOR_IMPL */
[*]#else /* We are on Win32 and we have winsock and ACE_USE_SELECT_REACTOR_FOR_REACTOR_IMPL is not defined */
[*]#if defined (ACE_USE_MSG_WFMO_REACTOR_FOR_REACTOR_IMPL)
[*]# include "ace/Msg_WFMO_Reactor.h"
[*]#else
[*]# include "ace/WFMO_Reactor.h"
[*]#endif /* ACE_USE_MSG_WFMO_REACTOR_FOR_REACTOR_IMPL */
[*]#endif /* !defined (ACE_WIN32) || !defined (ACE_HAS_WINSOCK2) || (ACE_HAS_WINSOCK2 == 0) || defined (ACE_USE_SELECT_REACTOR_FOR_REACTOR_IMPL) */
[*]
[*]/*
[*] * End comment hook.
[*] */
[*]//@@ REACTOR_SPL_COMMENT_INCLUDE_END_HOOK
[*]
[*]#include "ace/Static_Object_Lock.h"
[*]#include "ace/Framework_Component.h"
[*]#include "ace/Guard_T.h"
[*]#include "ace/Recursive_Thread_Mutex.h"
[*]
[*]#if !defined (__ACE_INLINE__)
[*]#include "ace/Reactor.inl"
[*]#endif /* __ACE_INLINE__ */
[*]
[*]ACE_BEGIN_VERSIONED_NAMESPACE_DECL
[*]
[*]ACE_ALLOC_HOOK_DEFINE(ACE_Reactor)
[*]
[*]ACE_Reactor::ACE_Reactor (ACE_Reactor_Impl *impl,
[*] bool delete_implementation)
[*]: implementation_ (0),
[*] delete_implementation_ (delete_implementation)
[*]{
[*]this->implementation (impl);
[*]
[*]if (this->implementation () == 0)
[*] {
[*]/*
[*] * Hook to specialize the reactor implementation with the concrete
[*] * Reactor implementation known at compile time. This hook will
[*] * cause the conditionally defined code to be commented out and
[*] * the concrete Reactor directly created.
[*] */
[*]//@@ REACTOR_SPL_CONSTRUCTOR_COMMENT_HOOK_START
[*]#if !defined (ACE_WIN32) \
[*] || !defined (ACE_HAS_WINSOCK2) || (ACE_HAS_WINSOCK2 == 0) \
[*] || defined (ACE_USE_SELECT_REACTOR_FOR_REACTOR_IMPL) \
[*] || defined (ACE_USE_TP_REACTOR_FOR_REACTOR_IMPL) \
[*] || defined (ACE_USE_DEV_POLL_REACTOR_FOR_REACTOR_IMPL)
[*]#if defined (ACE_USE_TP_REACTOR_FOR_REACTOR_IMPL)
[*] ACE_NEW (impl,
[*] ACE_TP_Reactor);
[*]#else
[*]# if defined (ACE_USE_DEV_POLL_REACTOR_FOR_REACTOR_IMPL)
[*] ACE_NEW (impl,
[*] ACE_Dev_Poll_Reactor);
[*]# else
[*] ACE_NEW (impl,
[*] ACE_Select_Reactor);
[*]# endif /* ACE_USE_DEV_POLL_REACTOR_FOR_REACTOR_IMPL */
[*]#endif /* ACE_USE_TP_REACTOR_FOR_REACTOR_IMPL */
[*]#else /* We are on Win32 and we have winsock and ACE_USE_SELECT_REACTOR_FOR_REACTOR_IMPL is not defined */
[*]#if defined (ACE_USE_MSG_WFMO_REACTOR_FOR_REACTOR_IMPL)
[*] ACE_NEW (impl,
[*] ACE_Msg_WFMO_Reactor);
[*]#else
[*] ACE_NEW (impl,
[*] ACE_WFMO_Reactor);
[*]#endif /* ACE_USE_MSG_WFMO_REACTOR_FOR_REACTOR_IMPL */
[*]#endif /* !defined (ACE_WIN32) || !defined (ACE_HAS_WINSOCK2) || (ACE_HAS_WINSOCK2 == 0) || defined (ACE_USE_SELECT_REACTOR_FOR_REACTOR_IMPL) */
[*]
[*]/*
[*] * End hook.
[*] */
[*]//@@ REACTOR_SPL_CONSTRUCTOR_COMMENT_HOOK_END
[*]
[*] this->implementation (impl);
[*] this->delete_implementation_ = true;
[*] }
[*]}
[*]
[*]ACE_Reactor::~ACE_Reactor (void)
[*]{
[*]this->implementation ()->close ();
[*]if (this->delete_implementation_)
[*] delete this->implementation ();
[*]}
[*]
[*]// Process-wide ACE_Reactor.
[*]ACE_Reactor *ACE_Reactor::reactor_ = 0;
[*]
[*]// Controls whether the Reactor is deleted when we shut down (we can
[*]// only delete it safely if we created it!)
[*]bool ACE_Reactor::delete_reactor_ = false;
[*]
[*]ACE_Reactor *
[*]ACE_Reactor::instance (void)
[*]{
[*]ACE_TRACE ("ACE_Reactor::instance");
[*]
[*]if (ACE_Reactor::reactor_ == 0)
[*] {
[*] // Perform Double-Checked Locking Optimization.
[*] ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon,
[*] *ACE_Static_Object_Lock::instance (), 0));
[*]
[*] if (ACE_Reactor::reactor_ == 0)
[*] {
[*] ACE_NEW_RETURN (ACE_Reactor::reactor_,
[*] ACE_Reactor,
[*] 0);
[*] ACE_Reactor::delete_reactor_ = true;
[*] ACE_REGISTER_FRAMEWORK_COMPONENT(ACE_Reactor, ACE_Reactor::reactor_)
[*] }
[*] }
[*]return ACE_Reactor::reactor_;
[*]}
[*]
[*]ACE_Reactor *
[*]ACE_Reactor::instance (ACE_Reactor *r, bool delete_reactor)
[*]{
[*]ACE_TRACE ("ACE_Reactor::instance");
[*]
[*]ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon,
[*] *ACE_Static_Object_Lock::instance (), 0));
[*]ACE_Reactor *t = ACE_Reactor::reactor_;
[*]ACE_Reactor::delete_reactor_ = delete_reactor;
[*]
[*]ACE_Reactor::reactor_ = r;
[*]
[*]// We can't register the Reactor singleton as a framework component twice.
[*]// Therefore we test to see if we had an existing reactor instance, which
[*]// if so means it must have already been registered.
[*]if (t == 0)
[*] ACE_REGISTER_FRAMEWORK_COMPONENT(ACE_Reactor, ACE_Reactor::reactor_);
[*]
[*]return t;
[*]}
[*]
[*]void
[*]ACE_Reactor::close_singleton (void)
[*]{
[*]ACE_TRACE ("ACE_Reactor::close_singleton");
[*]
[*]ACE_MT (ACE_GUARD (ACE_Recursive_Thread_Mutex, ace_mon,
[*] *ACE_Static_Object_Lock::instance ()));
[*]
[*]if (ACE_Reactor::delete_reactor_)
[*] {
[*] delete ACE_Reactor::reactor_;
[*] ACE_Reactor::reactor_ = 0;
[*] ACE_Reactor::delete_reactor_ = false;
[*] }
[*]}
[*]
[*]const ACE_TCHAR *
[*]ACE_Reactor::dll_name (void)
[*]{
[*]return ACE_TEXT ("ACE");
[*]}
[*]
[*]const ACE_TCHAR *
[*]ACE_Reactor::name (void)
[*]{
[*]return ACE_TEXT ("ACE_Reactor");
[*]}
[*]
[*]int
[*]ACE_Reactor::check_reconfiguration (ACE_Reactor *)
[*]{
[*]#if !defined (ACE_HAS_WINCE)&&!defined (ACE_LACKS_ACE_SVCCONF)
[*]if (ACE_Service_Config::reconfig_occurred ())
[*] {
[*] ACE_Service_Config::reconfigure ();
[*] return 1;
[*] }
[*]#endif /* ! ACE_HAS_WINCE || ! ACE_LACKS_ACE_SVCCONF */
[*]return 0;
[*]}
[*]
[*]int
[*]ACE_Reactor::run_reactor_event_loop (REACTOR_EVENT_HOOK eh)
[*]{
[*]ACE_TRACE ("ACE_Reactor::run_reactor_event_loop");
[*]
[*]if (this->reactor_event_loop_done ())
[*] return 0;
[*]
[*]while (1)
[*] {
[*] int const result = this->implementation_->handle_events ();
[*]
[*] if (eh != 0 && (*eh)(this))
[*] continue;
[*] else if (result == -1 && this->implementation_->deactivated ())
[*] return 0;
[*] else if (result == -1)
[*] return -1;
[*] }
[*]
[*]ACE_NOTREACHED (return 0;)
[*]}
[*]
[*]int
[*]ACE_Reactor::run_alertable_reactor_event_loop (REACTOR_EVENT_HOOK eh)
[*]{
[*]ACE_TRACE ("ACE_Reactor::run_alertable_reactor_event_loop");
[*]
[*]if (this->reactor_event_loop_done ())
[*] return 0;
[*]
[*]while (1)
[*] {
[*] int const result = this->implementation_->alertable_handle_events ();
[*]
[*] if (eh != 0 && (*eh)(this))
[*] continue;
[*] else if (result == -1 && this->implementation_->deactivated ())
[*] return 0;
[*] else if (result == -1)
[*] return -1;
[*] }
[*]
[*]ACE_NOTREACHED (return 0;)
[*]}
[*]
[*]int
[*]ACE_Reactor::run_reactor_event_loop (ACE_Time_Value &tv,
[*] REACTOR_EVENT_HOOK eh)
[*]{
[*]ACE_TRACE ("ACE_Reactor::run_reactor_event_loop");
[*]
[*]if (this->reactor_event_loop_done ())
[*] return 0;
[*]
[*]while (1)
[*] {
[*] int result = this->implementation_->handle_events (tv);
[*]
[*] if (eh != 0 && (*eh) (this))
[*] continue;
[*] else if (result == -1)
[*] {
[*] if (this->implementation_->deactivated ())
[*] result = 0;
[*] return result;
[*] }
[*] else if (result == 0)
[*] {
[*] // The <handle_events> method timed out without dispatching
[*] // anything.Because of rounding and conversion errors and
[*] // such, it could be that the wait loop (WFMO, select, etc.)
[*] // timed out, but the timer queue said it wasn't quite ready
[*] // to expire a timer. In this case, the ACE_Time_Value we
[*] // passed into handle_events won't have quite been reduced
[*] // to 0, and we need to go around again. If we are all the
[*] // way to 0, just return, as the entire time the caller
[*] // wanted to wait has been used up.
[*] if (tv.usec () > 0)
[*] continue;
[*] return 0;
[*] }
[*] // Else there were some events dispatched; go around again
[*] }
[*]
[*]ACE_NOTREACHED (return 0;)
[*]}
[*]
[*]int
[*]ACE_Reactor::run_alertable_reactor_event_loop (ACE_Time_Value &tv,
[*] REACTOR_EVENT_HOOK eh)
[*]{
[*]ACE_TRACE ("ACE_Reactor::run_alertable_reactor_event_loop");
[*]
[*]if (this->reactor_event_loop_done ())
[*] return 0;
[*]
[*]for (;;)
[*] {
[*] int result = this->implementation_->alertable_handle_events (tv);
[*]
[*] if (eh != 0 && (*eh)(this))
[*] continue;
[*] else if (result == -1 && this->implementation_->deactivated ())
[*] return 0;
[*] else if (result <= 0)
[*] return result;
[*] }
[*]}
[*]
[*]int
[*]ACE_Reactor::register_handler (ACE_Event_Handler *event_handler,
[*] ACE_Reactor_Mask mask)
[*]{
[*]// Remember the old reactor.
[*]ACE_Reactor *old_reactor = event_handler->reactor ();
[*]
[*]// Assign *this* <Reactor> to the <Event_Handler>.
[*]event_handler->reactor (this);
[*]
[*]int result = this->implementation ()->register_handler (event_handler, mask);
[*]if (result == -1)
[*] // Reset the old reactor in case of failures.
[*] event_handler->reactor (old_reactor);
[*]
[*]return result;
[*]}
[*]
[*]int
[*]ACE_Reactor::register_handler (ACE_HANDLE io_handle,
[*] ACE_Event_Handler *event_handler,
[*] ACE_Reactor_Mask mask)
[*]{
[*]// Remember the old reactor.
[*]ACE_Reactor *old_reactor = event_handler->reactor ();
[*]
[*]// Assign *this* <Reactor> to the <Event_Handler>.
[*]event_handler->reactor (this);
[*]
[*]int result = this->implementation ()->register_handler (io_handle,
[*] event_handler,
[*] mask);
[*]if (result == -1)
[*] // Reset the old reactor in case of failures.
[*] event_handler->reactor (old_reactor);
[*]
[*]return result;
[*]}
[*]
[*]#if defined (ACE_WIN32)
[*]
[*]int
[*]ACE_Reactor::register_handler (ACE_Event_Handler *event_handler,
[*] ACE_HANDLE event_handle)
[*]{
[*]// Remember the old reactor.
[*]ACE_Reactor *old_reactor = event_handler->reactor ();
[*]
[*]// Assign *this* <Reactor> to the <Event_Handler>.
[*]event_handler->reactor (this);
[*]
[*]int result = this->implementation ()->register_handler (event_handler,
[*] event_handle);
[*]if (result == -1)
[*] // Reset the old reactor in case of failures.
[*] event_handler->reactor (old_reactor);
[*]
[*]return result;
[*]}
[*]
[*]#endif /* ACE_WIN32 */
[*]
[*]int
[*]ACE_Reactor::register_handler (ACE_HANDLE event_handle,
[*] ACE_HANDLE io_handle,
[*] ACE_Event_Handler *event_handler,
[*] ACE_Reactor_Mask mask)
[*]{
[*]// Remember the old reactor.
[*]ACE_Reactor *old_reactor = event_handler->reactor ();
[*]
[*]// Assign *this* <Reactor> to the <Event_Handler>.
[*]event_handler->reactor (this);
[*]
[*]int result = this->implementation ()->register_handler (event_handle,
[*] io_handle,
[*] event_handler,
[*] mask);
[*]if (result == -1)
[*] // Reset the old reactor in case of failures.
[*] event_handler->reactor (old_reactor);
[*]
[*]return result;
[*]}
[*]
[*]int
[*]ACE_Reactor::register_handler (const ACE_Handle_Set &handles,
[*] ACE_Event_Handler *event_handler,
[*] ACE_Reactor_Mask mask)
[*]{
[*]// Remember the old reactor.
[*]ACE_Reactor *old_reactor = event_handler->reactor ();
[*]
[*]// Assign *this* <Reactor> to the <Event_Handler>.
[*]event_handler->reactor (this);
[*]
[*]int result = this->implementation ()->register_handler (handles,
[*] event_handler,
[*] mask);
[*]if (result == -1)
[*] // Reset the old reactor in case of failures.
[*] event_handler->reactor (old_reactor);
[*]
[*]return result;
[*]}
[*]
[*]long
[*]ACE_Reactor::schedule_timer (ACE_Event_Handler *event_handler,
[*] const void *arg,
[*] const ACE_Time_Value &delta,
[*] const ACE_Time_Value &interval)
[*]{
[*]// Remember the old reactor.
[*]ACE_Reactor *old_reactor = event_handler->reactor ();
[*]
[*]// Assign *this* <Reactor> to the <Event_Handler>.
[*]event_handler->reactor (this);
[*]
[*]long result = this->implementation ()->schedule_timer (event_handler,
[*] arg,
[*] delta,
[*] interval);
[*]if (result == -1)
[*] // Reset the old reactor in case of failures.
[*] event_handler->reactor (old_reactor);
[*]
[*]return result;
[*]}
[*]
[*]int
[*]ACE_Reactor::schedule_wakeup (ACE_Event_Handler *event_handler,
[*] ACE_Reactor_Mask masks_to_be_added)
[*]{
[*]// Remember the old reactor.
[*]ACE_Reactor *old_reactor = event_handler->reactor ();
[*]
[*]// Assign *this* <Reactor> to the <Event_Handler>.
[*]event_handler->reactor (this);
[*]
[*]int result = this->implementation ()->schedule_wakeup (event_handler,
[*] masks_to_be_added);
[*]if (result == -1)
[*] // Reset the old reactor in case of failures.
[*] event_handler->reactor (old_reactor);
[*]
[*]return result;
[*]}
[*]
[*]int
[*]ACE_Reactor::notify (ACE_Event_Handler *event_handler,
[*] ACE_Reactor_Mask mask,
[*] ACE_Time_Value *tv)
[*]{
[*]// First, try to remember this reactor in the event handler, in case
[*]// the event handler goes away before the notification is delivered.
[*]if (event_handler != 0 && event_handler->reactor () == 0)
[*] {
[*] event_handler->reactor (this);
[*] }
[*]return this->implementation ()->notify (event_handler, mask, tv);
[*]}
[*]
[*]int
[*]ACE_Reactor::reset_timer_interval
[*](long timer_id,
[*] const ACE_Time_Value &interval)
[*]{
[*]ACE_TRACE ("ACE_Reactor::reset_timer_interval");
[*]
[*]return this->implementation ()->reset_timer_interval (timer_id, interval);
[*]}
[*]
[*]int
[*]ACE_Reactor::cancel_timer (ACE_Event_Handler *event_handler,
[*] int dont_call_handle_close)
[*]{
[*]return this->implementation ()->cancel_timer (event_handler,
[*] dont_call_handle_close);
[*]}
[*]
[*]int
[*]ACE_Reactor::cancel_timer (long timer_id,
[*] const void **arg,
[*] int dont_call_handle_close)
[*]{
[*]return this->implementation ()->cancel_timer (timer_id,
[*] arg,
[*] dont_call_handle_close);
[*]}
[*]
[*]ACE_END_VERSIONED_NAMESPACE_DECL
二、ACE Reactor 框架类1、ACE_Time_Value ：提供时间和持续时间的可移植、规范化的表示，使用C++运算符重载来简化与时间有关的算术和关系运算。2、ACE_Event_Handler ：抽象类，其接口定义的挂钩方法是 ACE_Reactor 回调的目标。大多数通过ACE开发的应用事件处理器都是ACE_Event_Handler的后代。3、ACE_Timer_Queue：抽象类，定义定时器队列的能力和接口。ACE含有多种派生自ACE_Timer_Queue的类，为不同的定时机制提供了灵活的支持。4、ACE_ Reactor：提供一个接口，用来在 Reactor 框架中管理事件处理器登记，并执行事件循环来驱动事件检测、多路分离的分派。这些类在 Reactor 模式中扮演了以下角色：1、事件基础设施层类(Event Infrastructure Layer Classes) 该类同步地检测事件并多路分离给事件处理器，并随即分派与之相关联的事件处理器挂钩方法。 ACE Reactor 框架中的基础设施层组件包括 ACE_Time_Value、ACE_Event_Handler、ACE定时器队列类，以及 ACE_Reactor的各种实现。2、应用层类(Application Layer Classes) 该类定义事件处理器，以在其挂钩方法中执行应用所定义的处理。在 ACE Reactor 框架中，应用层类都是 ACE_Event_Handler 的后代。三、ACE Reactor 框架的优点：1、广泛的可移植性。可以对框架进行配置，使用多种 OS 事件多路分离机制。2、使事件检测、多路分离，以及分派自动化。通过消除对不可移植的本地 OS 事件多路分离 API 的依赖，ACE Reactor 框架为应用提供了统一的面向对象事件检测，多路分离，以及分派机制，可以向 ACE_Reactor 登记事件处理器对象来处理各种类型的事件。3、透明的可扩展性。框架通过继承的动态绑定，采用挂钩方法，解除了“较低级的事件机制”(如检测多个I/O句柄上的事件，使定时器到期，以及多路分离和分派适当的事件处理器的方法来处理事件) 与“较高级的应用事件处理策略”(如连接建立策略、数据整编和解整编，以及对客户请求的处理) 的耦合。如此的设计使开发者能在不修改已有应用代码的情况下，对 ACE Reactor 框架进行透明扩展。4、增加复用并使错误减至最少。ACE Reactor 框架的事件检测、多路分离，以及分派机制是通用的，因而可被许多网络化应用复用。如此的事务分离使得开发者能够专注于高级的、应用所定义的事件处理器策略，而不是反复地与低级机制进行斗争。5、高效的事件多路分离。ACE Reactor 框架可高效地执行其事件多路分离和分派逻辑，如 ACE_Select_Reactor 使用了ACE_Handler_Set_Iteratorwrapper facade(包装外观)。它的 Iterator 模式中的优化实现基于成熟的算法，将运行时复杂度大大降低，从而极大地提高了大型应用的运行时性能。
更多文章欢迎访问：http://blog.csdn.net/wallwind
好文。没人回复？应该能回复的吧、:lol 注释太少 看到这么多代码 ，有点晕了。 好贴，版主应该增加这里代码级说明的帖子，另外，如果能够从总体架构上说明为什么这么设计，以及这样设计优点就更好了 画个图示意下就更好了！好帖！
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