这个示例将用ACE Proactor来实现echo server 代码量差不多只有完成端口的1/3 ACE Reactor的实现 http://www.cppblog.com/sandy/archive/2006/02/17/3308.html 完成端口的实现 http://www.cppblog.com/sandy/archive/2007/06/06/25670.html 当然如果你理解了完成端口，ACE Proactor就很简单了 大概的过程是这个样子的 1.使用ACE_Asynch_Acceptor来建立服务器端的socket,然后bind,listen等待Accept并创建IOCP (相对于ACE Reactor的ACE_Acceptor） 2.当出现完成事件（GetQueuedCompletionStatus）返回时，调用用户的处理接口来处理，这是一个派生于ACE_Service_Handler的子类 （相对于ACE Reactor的ACE_Svc_Handler） ACE Reactor和Proactor最大的不同就是 ACE Reactor在处理读写事件的时候，要使用peer().recv/send来接收/发送数据。 而ACE Proactor在处理读写事件的时候,数据已经被读到用户的缓冲区了，典型的"先斩后奏" ACE Proactor比ACE Reactor麻烦的地方是需要手工去投递异步读写的请求。
可以通过下面的代码来去体会。 #ifdef _DEBUG #pragma comment(lib,"ACED.lib") #else #pragma comment(lib,"ACE.lib") #endif #include "ace/OS_main.h" #include "ace/OS_NS_sys_socket.h" #include "ace/ACE.h" #include "ace/Service_Object.h" #include "ace/Asynch_IO.h" #include "ace/Proactor.h" #include "ace/message_block.h" #include "ace/Asynch_Acceptor.h" #include "ace/INET_Addr.h" class Echo_Service : public ACE_Service_Handler { public: ~Echo_Service () { if (this->handle () != ACE_INVALID_HANDLE) ACE_OS::closesocket (this->handle ()); } virtual void open (ACE_HANDLE h, ACE_Message_Block&) { this->handle (h); if (this->reader_.open (*this) != 0 || this->writer_.open (*this) != 0 ) { ACE_ERROR ((LM_ERROR, ACE_TEXT ("%p/n"),ACE_TEXT ("Echo_Service open"))); delete this; return; } ACE_Message_Block *mb; ACE_NEW_NORETURN (mb, ACE_Message_Block (1024)); if (this->reader_.read (*mb, mb->space ()) != 0) { ACE_ERROR ((LM_ERROR, ACE_TEXT ("%p/n"),ACE_TEXT ("Echo_Service begin read"))); mb->release (); delete this; return; } } virtual void handle_read_stream(const ACE_Asynch_Read_Stream::Result &result) { ACE_Message_Block &mb = result.message_block (); if (!result.success () || result.bytes_transferred () == 0) { mb.release (); delete this; } else { if (this->writer_.write (mb, mb.length ()) == -1) { ACE_ERROR ((LM_ERROR, ACE_TEXT ("%p/n"), ACE_TEXT ("starting write"))); mb.release (); } else { ACE_Message_Block *new_mb; ACE_NEW_NORETURN (new_mb, ACE_Message_Block (1024)); this->reader_.read (*new_mb, new_mb->space ()); } } return; } virtual void handle_write_stream (const ACE_Asynch_Write_Stream::Result &result) { ACE_Message_Block &mb = result.message_block (); mb.release (); return; } private: ACE_Asynch_Read_Stream reader_; ACE_Asynch_Write_Stream writer_; }; typedef ACE_Asynch_Acceptor<Echo_Service> MyAcceptor; int main(int argc, char *argv[]) { ACE_INET_Addr addr(1500); MyAcceptor server; if(server.open(addr)==-1) { ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("(%P|%t) %p/n"), ACE_TEXT ("bind failed"))); return 1; } while(1){ ACE_Proactor::instance ()->proactor_run_event_loop (); } return 0; }
转自：http://www.cppblog.com/sandy/archive/2007/06/19/26633.html
