命名管道——大家讨论

[smatter]

我最近在研究命名管道，并且实现了简单的操作。在使用过程中也遇到很多问题，拿出来大家一起讨论讨论。我在网上找到过一些关于命名管道的文章和例子，要么是很简单，要么就是很复杂，嘿嘿！

问题一：
在服务器端，我想用GetOverlappedResult来判断有没有数据发送过来的话，创建和设置命名管道要注意哪些地方？
现在的情况是客户端与服务器端建立了连接，并且向服务器端发送了数据，在服务器端我直接用ReadFile的话，是能够正常收到的，但是我想先用GetOverlappedResult来判断有没有数据的到来，每次都是失败的。

问题二：
我一直想知道OVERLAPPED结构里的hEvent是派什么用处的，ConnectNamedPipe、ReadFile、GetOverlappedResult都会用到，这个事件句柄是不是当这些操作（异步）有效时被触发？

***********
暂时到这里

[smatter]

勇敢的心
WaitSingleObject(HANDLE hHandle, DWORD dwMilliseconds)第二个参数你设置多少？是无限等待，还是什么？
while里为什么是ReadFile->WaitSingleObject呢？那后面还是要一次ReadFile吗？？？才是真正读取了数据。

能不能用GetOverlappedResult直接去判断hPipeHandle有没有数据到来，然后一次性去接受数据？

[smatter]

kingzai
这个例子是MSDN里的，我简单看过些，嘿嘿！有很多地方还是不太了解。

[smatter]

ms-help://MS.VSCC.2003/MS.MSDNQTR.2003FEB.2052/ipc/base/named_pipe_server_using_overlapped_i_o.htm

写的比较复杂，看不懂！

[magician21cn]

好复杂的程序阿，管道问题我还没有接触过，不过马上就要接触拉

[smatter]

复杂到还好，就是有一些概念不清楚不太明白，因为赶时间，我先用socket来代替算了！

[smatter]

各位大虾多多提点提点！！！

[kingzai]

see this example hwo to use GetOverlappedResult and namedpipe
#include<windows.h>
#include<stdio.h>
#define NUM_PIPES 5
#define BUFFER_SIZE 256

void main(void)
{
HANDLE PipeHandles[NUM_PIPES];
DWORD BytesTransferred;
CHAR Buffer[NUM_PIPES][BUFFER_SIZE];
INT i;
OVERLAPPED Ovlap[NUM_PIPES];
HANDLE Event[NUM_PIPES];
BOOL DataRead[NUM_PIPES];
DWORD Ret;
DWORD Pipe;
for(i=0;i<NUM_PIPES;i++)
{
if((PipeHandles[i]=CreateNamedPipe("\\\\.\\PIPE\\ZHOUJ",PIPE_ACCESS_DUPLEX|FILE_FLAG_OVERLAPPED,PIPE_TYPE_BYTE|PIPE_READMODE_BYTE,NUM_PIPES,0,0,1000,NULL))==INVALID_HANDLE_VALUE)
{
printf("CreateNamedPipe for pipe %d failed with error %d\n",i,GetLastError());
return ;
}
if((Event[i]=CreateEvent(NULL,TRUE,FALSE,NULL))==NULL)
{
printf("CreateEvent for pipe %d failed with error %d\n",i,GetLastError());
continue;
}
DataRead[i]=FALSE;
ZeroMemory(&Ovlap[i],sizeof(OVERLAPPED));
Ovlap[i].hEvent=Event[i];
if(ConnectNamedPipe(PipeHandles[i],&Ovlap[i])==0)
{
if(GetLastError()!=ERROR_IO_PENDING)
{
printf("ConnectNamedPipe for pipe %d failed with error %d\n",i,GetLastError());
return;
}
}
}
printf("Server is Now Running\n");
while(1)
{
if((Ret=WaitForMultipleObjects(NUM_PIPES,Event,FALSE,INFINITE))==WAIT_FAILED)
{

printf("WaitForMultipleObjects failed with error %d\n",GetLastError());
return;
}

Pipe=Ret-WAIT_OBJECT_0;
ResetEvent(Event[Pipe]);
if(GetOverlappedResult(PipeHandles[Pipe],&Ovlap[Pipe],&BytesTransferred,TRUE)==0)
{
printf("GetOverlapped result failed %d start over\n",GetLastError());
if(DisconnectNamedPipe(PipeHandles[Pipe])==0)
{
printf("DisconnectNamedPipe failed with error %d\n",GetLastError());
return ;
}
if(ConnectNamedPipe(PipeHandles[Pipe],&Ovlap[Pipe])==0)
{
if(GetLastError()!=ERROR_IO_PENDING)
{
printf("ConnectNamedPipe for pipe %d failed with error %d\n",i,GetLastError());
CloseHandle(PipeHandles[Pipe]);
}
DataRead[Pipe]=FALSE;
}
else
{
if(DataRead[Pipe]==FALSE)
{
ZeroMemory(&Ovlap[Pipe],sizeof(OVERLAPPED));
Ovlap[Pipe].hEvent=Event[Pipe];
if(ReadFile(PipeHandles[Pipe],Buffer[Pipe],BUFFER_SIZE,NULL,&Ovlap[Pipe])==0)
{
if(GetLastError()!=ERROR_IO_PENDING)
{
printf("ReadFile failed with error %d\n",GetLastError());
}
}
DataRead[Pipe]=TRUE;
}
else
{
printf("Received %d bytes,echo bytes back\n",BytesTransferred);
ZeroMemory(&Ovlap[Pipe],sizeof(OVERLAPPED));
Ovlap[Pipe].hEvent=Event[Pipe];
if(WriteFile(PipeHandles[Pipe],Buffer[Pipe],BytesTransferred,NULL,&Ovlap[Pipe])==0)
{
if(GetLastError()!=ERROR_IO_PENDING)
{
printf("WriteFile failed with error %d\n",GetLastError);
}
}
DataRead[Pipe]=FALSE;
}
}
}
}
}

[otrice]

学习

[yszmax]

挑张板凳来学习

[oyljerry]

hPipeHandle=Win32API.CreateNamedPipe("\\\\.\\pipe\\pipetest",
PIPE_ACCESS_DUPLEX|FILE_FLAG_OVERLAPPED,
intPipeMode,
Win32API.CONST.PIPE_UNLIMITED_INSTANCES,
1000,
1000,
NMPWAIT_USE_DEFAULT_WAIT,
null);
ConnectNamedPipe(hPipeHandle, null);


OVERLAPPED ol;
ol.hEvent=CreateEvent(NULL, TRUE, FALSE, NULL);
ol.Internal=UIntPtr.Zero;
ol.InternalHigh=UIntPtr.Zero;
ol.Offset = 0;
ol.OffsetHigh = 0;
while(1)
{
ReadFile(hPipeHandle,btReceBuff,intBuffSize,&intReceiveSize,&ol);
WaitSingleObject(ol.hEvent);
GetOverlappedResult(hPipeHandle, &ol,&intReceiveSize, false);
.
.

}

[smatter]

已经基本掌握管道通信，呵呵！谢谢大家了！