匿名管道[继续]，和子进程数据交换发生堵塞。[附我的测试代码]

我用匿名管道师父进程和一个Shell交流数据。
现在用于输入输出的两个管道已经建立。--》ok

从父窗口输入字符串，通过跟踪，写管道的WriteFile（）已经过去。
然后从管道中读取数据时ReadFile发生堵塞，。。。。。。实在搞不明白！！！
由于刚刚接触管道，线程创建等知识，
试了几天了，各种各样的问题不断。
实在扛不住了，特向大家求助。

Parent

#include <windows.h> 

#include <tchar.h>

#include <stdio.h> 



//句柄说明

// {Parent Write}-> {g_hChildStd_IN_Wr <-管道-> g_hChildStd_IN_Rd} -> {Child STDINPUT}

HANDLE g_hChildStd_IN_Rd = NULL;

HANDLE g_hChildStd_IN_Wr = NULL;

// {Parent Read}<- {g_hChildStd_OUT_Rd <-管道-> g_hChildStd_OUT_Wr} ->{ Child STDOUTPUT}

HANDLE g_hChildStd_OUT_Rd = NULL;

HANDLE g_hChildStd_OUT_Wr = NULL;



//产生子进程

void CreateChildProcess(void); 

//错误显示

void ErrorExit(PTSTR); 



//写入管道

void WriteToPipe(char *	chBuf ) 

{ 

	DWORD dwWritten = 0; 

	BOOL bSuccess = FALSE;

	

	bSuccess = WriteFile(g_hChildStd_IN_Wr, chBuf, strlen(chBuf), &dwWritten, NULL);

	if ( ! bSuccess ) ErrorExit(TEXT("WriteToPipe() ")); 

	

} 



//从管道中读数据

void ReadFromPipe(char * chBuf ) 

{ 

	DWORD dwRead = 0; 

	BOOL bSuccess = FALSE;

	bSuccess = ReadFile( g_hChildStd_OUT_Rd, chBuf, sizeof(chBuf)-1, &dwRead, NULL);

	if( ! bSuccess ) ErrorExit(TEXT("ReadFromPipe() ")); 

	chBuf[dwRead] ='\0';

} 





int _tmain(int argc, TCHAR *argv[]) 

{ 

	printf("\n->Start of parent execution.\n");



// 管道产生

	SECURITY_ATTRIBUTES saAttr; 	

	// Set the bInheritHandle flag so pipe handles are inherited. 

	saAttr.nLength = sizeof(SECURITY_ATTRIBUTES); 

	saAttr.bInheritHandle = TRUE;  //管道句柄可继承

	saAttr.lpSecurityDescriptor = NULL; 

	

	//产生一个用于子进程STDOUT的管道

	if ( ! CreatePipe(&g_hChildStd_OUT_Rd, &g_hChildStd_OUT_Wr, &saAttr, 0) ) 

		ErrorExit(TEXT("StdoutRd CreatePipe")); 

	

	// 设置 用于子进程STDOUT的管道 的读取端不可继承

	if ( ! SetHandleInformation(g_hChildStd_OUT_Rd, HANDLE_FLAG_INHERIT, 0) )

		ErrorExit(TEXT("Stdout SetHandleInformation")); 

	

	// 为子进程的输出重定向做准备

	HANDLE hOriginalStdOut = GetStdHandle(STD_OUTPUT_HANDLE);

	if ( !SetStdHandle(STD_OUTPUT_HANDLE, g_hChildStd_OUT_Wr))

	{

		ErrorExit(TEXT("Stdout SetStdHandle")); 

	}

	

	//	产生一个用于子进程STDIN的管道

	if (! CreatePipe(&g_hChildStd_IN_Rd, &g_hChildStd_IN_Wr, &saAttr, 0)) 

		ErrorExit(TEXT("Stdin CreatePipe")); 

	

	// 设置 用于子进程STDIN的管道 的写入端不可继承

	if ( ! SetHandleInformation(g_hChildStd_IN_Wr, HANDLE_FLAG_INHERIT, 0) )

		ErrorExit(TEXT("Stdin SetHandleInformation")); 

	

	// 为子进程的输入重定向做准备

	HANDLE hOriginalStdIn = GetStdHandle(STD_INPUT_HANDLE);

	if (!SetStdHandle(STD_INPUT_HANDLE, g_hChildStd_IN_Rd))

	{

		ErrorExit(TEXT("Stdin SetStdHandle"));

	}

	

//产生子进程

	CreateChildProcess();

	

	// 回复正常输入输出

	if (!SetStdHandle(STD_OUTPUT_HANDLE, hOriginalStdOut))

	{

		ErrorExit(TEXT("Stdout SetStdHandle huifu"));

	}

	// else

	//本想在这里关闭该句柄，但是关闭之后发现父进程无法输出

	//	   CloseHandle(hOriginalStdOut);

	

	if (!SetStdHandle(STD_INPUT_HANDLE, hOriginalStdIn))

	{

		ErrorExit(TEXT("Stdin SetStdHandle"));

	}

	//else

	//{//本想在这里关闭该句柄，但是关闭之后发现父进程无法输入

	//	  CloseHandle(hOriginalStdIn);

	//}

	

	

	// 管道测试

	// 1)从父进程输入一串字符串放in里面

	// 2) 写in中的字符串到管道

	// 3) 从管道中读取进过子进程处理过的字符串

	// 4) 在父进程中输出，显示到控制台

	//

	char in[256];

	char out[256];

	char message1[] ="请输入：";

	char message2[] ="管道中是：";

	

	printf( "开始管道测试\n");

	

	for(;;)

	{ 

		puts(message1);

		gets(in);		// 1)从父进程输入一串字符串放in里面

		WriteToPipe(in); // 2) 写in中的字符串到管道

		

		ReadFromPipe(out);// 3) 从管道中读取进过子进程处理过的字符串

		puts(message2);

		puts(out);		// 4) 在父进程中输出，显示到控制台

	}

	

	//释放句柄

	if(g_hChildStd_IN_Rd != NULL)

	{

		CloseHandle(g_hChildStd_IN_Rd);

		g_hChildStd_IN_Rd = NULL;

	}

	if(g_hChildStd_IN_Wr != NULL)

	{

		CloseHandle(g_hChildStd_IN_Wr);

		g_hChildStd_IN_Wr = NULL;

	}

	if(g_hChildStd_OUT_Rd != NULL)

	{

		CloseHandle(g_hChildStd_OUT_Rd);

		g_hChildStd_OUT_Rd = NULL;

	}

	if(g_hChildStd_OUT_Wr != NULL)

	{

		CloseHandle(g_hChildStd_OUT_Wr);

		g_hChildStd_OUT_Wr = NULL;

	}

	CloseHandle(hOriginalStdOut);

	CloseHandle(hOriginalStdIn);

	

	return 0; 

} 

 

void CreateChildProcess()

// Create a child process that uses the previously created pipes for STDIN and STDOUT.

{ 

   TCHAR szCmdline[]=TEXT("child\\Debug\\child.exe");//子进程命令

   PROCESS_INFORMATION piProcInfo; 

   STARTUPINFO siStartInfo;

   BOOL bSuccess = FALSE; 

 

   ZeroMemory( &piProcInfo, sizeof(PROCESS_INFORMATION) );

   ZeroMemory( &siStartInfo, sizeof(STARTUPINFO) );

   siStartInfo.cb = sizeof(STARTUPINFO); 

   siStartInfo.hStdError = g_hChildStd_OUT_Wr;

   siStartInfo.hStdOutput = g_hChildStd_OUT_Wr;

   siStartInfo.hStdInput = g_hChildStd_IN_Rd;

   siStartInfo.dwFlags |= STARTF_USESTDHANDLES;

 

// Create the child process. 

   bSuccess = CreateProcess(NULL, 

      szCmdline,     // command line 

      NULL,          // process security attributes 

      NULL,          // primary thread security attributes 

      TRUE,          // handles are inherited 

      0,             // creation flags 

      NULL,          // use parent's environment 

      NULL,          // use parent's current directory 

      &siStartInfo,  // STARTUPINFO pointer 

      &piProcInfo);  // receives PROCESS_INFORMATION 

   

   // If an error occurs, exit the application. 

   if ( ! bSuccess ) 

      ErrorExit(TEXT("CreateProcess"));

   else 

   {

      // Close handles to the child process and its primary thread.

	  // Some applications might keep these handles to monitor the status

	  // of the child process, for example. 

      CloseHandle(piProcInfo.hProcess);

      CloseHandle(piProcInfo.hThread);

   }

}

// Format a readable error message, display a message box, 

// and exit from the application.

void ErrorExit(PTSTR lpszFunction) 

{ 

    LPVOID lpMsgBuf;

    LPVOID lpDisplayBuf;

    DWORD dw = GetLastError(); 



    FormatMessage(

        FORMAT_MESSAGE_ALLOCATE_BUFFER | 

        FORMAT_MESSAGE_FROM_SYSTEM |

        FORMAT_MESSAGE_IGNORE_INSERTS,

        NULL,

        dw,

        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),

        (LPTSTR) &lpMsgBuf,

        0, NULL );



    lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT, 

        (lstrlen((LPCTSTR)lpMsgBuf)+lstrlen((LPCTSTR)lpszFunction)+40)*sizeof(TCHAR));

	sprintf((LPTSTR)lpDisplayBuf,

		"%s failed with error %d: %s",

		lpszFunction, dw, lpMsgBuf);

    MessageBox(NULL, (LPCTSTR)lpDisplayBuf, TEXT("Error"), MB_OK); 



    LocalFree(lpMsgBuf);

    LocalFree(lpDisplayBuf);

    ExitProcess(1);

}

子程序Child

#include <stdio.h>

#include <string.h>



int main()

{

	char in[128] = {0};

	char out[128] ={"处理后的字符串为:"};

	gets(in);

	strcat(out,in);

	puts(out);

	return 0;

}

我的环境是VC6.0
大家编译时注意修改void CreateChildProcess()中
szCmdline[]=TEXT("child\\Debug\\child.exe");
子程序的路径