问题重复为命名频道

我有一个命名频道的服务器和客户端。 /这样做 VC++/.

服务器

可以

CreateNamedPipe

ConnectNamedPipe

WriteFile

断开

重复 2 到 4

客户

做。

CreateFile

ReadFile

执行顺序如下

服务器 -- CreateNamedPipe

客户 -- CreateFile

服务器 -- ConnectNamedPipe /必须立即返回，因为客户已连接/

服务器 -- WriteFile

客户 -- ReadFile

服务器 -- DisconnectNamedPipe

客户 - CloseHandle

去 2

它是第一次工作。 但是，当客户端尝试第二次连接时，会出现问题。 当客户试图连接时 /CreateFile/ 第二次

到

服务器如何完成 ConnectNamedPipe /但

后

disconnectnamedpipe/, 他收到了 ERROR_PIPE_BUSY. 如果客户原因，它有效 createfile 服务器发生后 ConnectNamedPipe.

无论如何，我可以连接客户端 /CreateFile/ 在服务器原因之前 ConnectNamedPipe /后 DisconnectNamedPipe/?

服务器代码：


pipe_handle.pipe = CreateNamedPipe/TEXT/"\\\\.\\pipe\\testpipe1"/,

 PIPE_ACCESS_OUTBOUND |

 FILE_FLAG_OVERLAPPED, // read/write access

 PIPE_TYPE_MESSAGE | // message type pipe

 PIPE_READMODE_MESSAGE | // message-read mode

 PIPE_WAIT, // blocking mode

 PIPE_UNLIMITED_INSTANCES, // max. instances

 BUFFER_SIZE, // output buffer size

 BUFFER_SIZE, // input buffer size

 2000, // client time-out

 NULL/;



if /pipe_handle.pipe == INVALID_HANDLE_VALUE/ {

 std::cout << "Error while creating pipe" << std::endl;

 return -1;

}

std::cout <<"Connecting to named pipe" << std::endl;



std::cout<< "Somebody connected to named pipe" << std::endl;



int ac;



for /ac=0; ac<2; ac++/ {



 char a[25];

 // Wait for some input. This helps me to start the client in other terminal.

 cin >> a;

 cout << "Connecting..." << endl;



 ConnectNamedPipe/pipe_handle.pipe, 0/;



 cout << "Connect pipe returned." << endl;



 // Wait for some input.

 cin >> a;

 string message = "Test message";

 DWORD bytes_written;



 if /!WriteFile/pipe_handle.pipe, message.c_str//, message.size//,

 &bytes_written, NULL// {



 DWORD er = GetLastError//;

 char errs[200];

 sprintf/errs, "Error : %ld", er/;

 std::cout << "Error communicating to client.";

 std::cout << errs;

 }

 std::cout << "Written to pipe";

 FlushFileBuffers/pipe_handle.pipe/;

 if /!DisconnectNamedPipe/pipe_handle.pipe// {

 std::cout << "Disconnect failed"<< GetLastError// << endl;

 } else {

 std::cout << "Disconnect successful"<<endl; !="" "="" "could="" "returned"="" &ol1,="" *="" -1;="" 0,="" 1="" ;="" <<="" [code]while="" all="" an="" are="" attributes="" break="" break;="" buf="reinterpret_cast&lt;char" busy,="" bytes_to_read="2000;" cbtowrite="/lstrlen/message/+1/*sizeof/TCHAR/;" char="" code]="" default="" dword="" error="" error_pipe_busy="" events[0]="ol1.hEvent;" events[1];="" existing="" exit="" false,="" file="" file_flag_overlapped,="" for="" generic_read,="" getlasterror="" handle="" hpipe="" if="" instances="" is="" lpszpipename,="" memset="" name="" nmpwait_use_default_wait="" no="" not="" null="" null,="" occurs.="" ol1="" ol1.hevent="CreateEvent/NULL," ol1.offset="0;" ol1.offsethigh="0;" ol1;="" open="" open_existing,="" opens="" other="" out."="" overlapped="" pipe="" pipe:="" return="" security="" sharing="" sizeof="" so="" sometime.="" std::cout="" std::cout<<="" std::endl;="" template="" than="" the="" timed="" true,="" valid.="" wait="" waitnamedpipe="" {="" }="" }[="" 客户代码：="">/malloc/bytes_to_read//;

DWORD bytes_read;



std::cout &lt;&lt; "Waiting for read" &lt;&lt; std::endl;

bool a = ReadFile/hPipe, buf, bytes_to_read, &amp;bytes_read, &amp;ol1/;





if / ! fSuccess/ {

 std::cout &lt;&lt; "WriteFile to pipe failed. GLE " &lt;&lt; GetLastError// &lt;&lt; std::endl; 

}

std::cout &lt;&lt; "Waiting for multiple objects" &lt;&lt; std::endl;

WaitForMultipleObjects/1, events, FALSE, INFINITE/;

std::cout &lt;&lt; "multiple objects returned" &lt;&lt; std::endl;

printf/"\nMessage sent to server"/;

CancelIo/hPipe/;

CloseHandle/hPipe/;


</endl;>
2021-03-21 添加评论
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没有找到相关结果

    已邀请:

    三叔

    赞同来自:

    如果你得到 ERROR_PIPE_BUSY 在呼唤时 CreateFile// 在客户端，您需要打电话 WaitNamedPipe//, 然后在返回时重复尝试。 如果你得到零返回 WaitNamedPipe//, 这意味着等待时间已过期，而不成为管道实惠。 如果你通过，你永远不会看到它发生了什么 nmpwait_wait_forever 超时。

    您还应该记住，管道可以再次变得忙碌之间 WaitNamedPipe// 和挑战 CreateFile//; 因此，您需要在循环中执行此操作。 类似于这个：


    while /true/
    
{
    
 hPipe = CreateFile/pipeName,
    
 GENERIC_READ | GENERIC_WRITE,
    
 0,
    
 0,
    
 OPEN_EXISTING,
    
 FILE_ATTRIBUTE_NORMAL,
    
 0/;
    
 if /hPipe == INVALID_HANDLE_VALUE/
    
 {
    
 if /GetLastError// == ERROR_PIPE_BUSY/
    
 {
    
 if /!WaitNamedPipe/pipeName, NMPWAIT_USE_DEFAULT_WAIT//
    
 continue; // timeout, try again
    
 }
    
 else
    
 return false; // error
    
 }
    
 else
    
 break; // success
    
}


    EDIT:

    我简化了你的代码，现在它正常工作。 服务器和客户工作。

    服务器

    :


    #include <windows.h>
    
#include <stdio.h>
    

    
int main/void/
    
{
    
 HANDLE pipe;
    
 const DWORD BUFFER_SIZE = 1024;
    

    
 pipe = CreateNamedPipe/"\\\\.\\pipe\\testpipe1",
    
 PIPE_ACCESS_OUTBOUND |
    
 FILE_FLAG_OVERLAPPED, // read/write access
    
 PIPE_TYPE_MESSAGE | // message type pipe
    
 PIPE_READMODE_MESSAGE | // message-read mode
    
 PIPE_WAIT, // blocking mode
    
 PIPE_UNLIMITED_INSTANCES, // max. instances
    
 BUFFER_SIZE, // output buffer size
    
 BUFFER_SIZE, // input buffer size
    
 2000, // client time-out
    
 NULL/;
    

    
 if /pipe == INVALID_HANDLE_VALUE/
    
 {
    
 printf/"Error while creating pipe\n"/;
    
 return -1;
    
 }
    
 printf/"Connecting to named pipe\n"/;
    

    
 int ac;
    

    
 for /ac=0; ac&lt;2; ac++/
    
 {
    
 // Wait for some input. This helps me to start the client in other terminal.
    
 printf/"Connecting...\n"/;
    

    
 ConnectNamedPipe/pipe, 0/;
    

    
 printf/"Connect pipe returned.\n"/;
    

    
 // Wait for some input.
    
 char * message = "Test message";
    
 DWORD bytes_written;
    

    
 if /!WriteFile/pipe, message, strlen/message/+1, &amp;bytes_written, NULL//
    
 {
    

    
 DWORD er = GetLastError//;
    
 char errs[200];
    
 sprintf_s/errs, "Error : %ld", er/;
    
 printf/"Error communicating to client.\n"/;
    
 printf/errs/;
    
 }
    
 printf/"Written to pipe\n"/;
    
 FlushFileBuffers/pipe/;
    
 if /!DisconnectNamedPipe/pipe//
    
 {
    
 printf/"Disconnect failed %d\n", GetLastError///;
    
 }
    
 else
    
 {
    
 printf/"Disconnect successful\n"/;
    
 }
    
 }
    
}


    客户

    :


    #include <windows.h>
    
#include <stdio.h>
    

    
int main/void/
    
{
    
 HANDLE hPipe;
    

    
 while /1/
    
 {
    

    
 printf/"Returned\n"/;
    
 hPipe = CreateFile/"\\\\.\\pipe\\testpipe1",
    
 GENERIC_READ, 
    
 0, // no sharing 
    
 NULL, // default security attributes
    
 OPEN_EXISTING, // opens existing pipe 
    
 0, // default attributes 
    
 NULL/; // no template file 
    

    
 // Break if the pipe handle is valid. 
    

    
 if /hPipe != INVALID_HANDLE_VALUE/
    
 break;
    

    

    
 // Exit if an error other than ERROR_PIPE_BUSY occurs. 
    

    
 if /GetLastError// != ERROR_PIPE_BUSY/
    
 {
    
 printf/"Could not open pipe %d\n", GetLastError///; 
    
 return -1;
    
 }
    

    
 // All pipe instances are busy, so wait for sometime.
    

    
 if / ! WaitNamedPipe/"\\\\.\\pipe\\testpipe1", NMPWAIT_USE_DEFAULT_WAIT//
    
 {
    
 printf/"Could not open pipe: wait timed out.\n"/; 
    
 }
    
 }
    

    

    
 char *message = "hello";
    
 DWORD cbToWrite = /strlen/message/+1/*sizeof/message[0]/;
    

    
 DWORD bytes_to_read = 2000;
    
 char * buf = reinterpret_cast<char *="">/malloc/bytes_to_read//;
    
 DWORD bytes_read;
    

    
 printf/"Waiting for read\n"/;
    
 bytes_read = 0;
    
 ReadFile/hPipe, buf, bytes_to_read, &amp;bytes_read, 0/;
    

    
 if /bytes_read &lt;= 0/
    
 {
    
 printf/"ReadFile from pipe failed. GLE \n"/; 
    
 }
    
 else
    
 printf/"Read %d bytes: %s\n", bytes_read, buf/;
    

    
 CloseHandle/hPipe/;
    
 return 0;
    
}


    </char></stdio.h></windows.h></stdio.h></windows.h>
    2021-03-21 0 0
    分享

    卫东

    赞同来自:

    在服务器端时，您决定打破连接时，您必须使用链：

    1/ CloseHandle /喇叭/;

    2/ DisconnectNamedPipe /喇叭/;
    2021-03-21 0 0
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