求助：GetLastError() == ERROR_IO_PENDING 问题？

[xmzh]

boolean serialWrite(HANDLE h, int bytesToWrite,char* buffer,int *bytesWritten)

{

OVERLAPPED os = {0};

int res;


memset(&os,0,sizeof(OVERLAPPED));

os.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

res = WriteFile(h,buffer,bytesToWrite,bytesWritten,&os);

if( fWriteStat == 0 )

{

if( GetLastError() == ERROR_IO_PENDING )

{

while ( GetOverlappedResult(h,&os,numberOfBytesWritten,TRUE) == 0 )

{

dwError=GetLastError();

if( dwError == ERROR_IO_INCOMPLETE )
{
continue;
}
else
{
return FALSE;
}

}

}

}

return TRUE;

}
运行半天就会始终返回false，谁知道怎么回事？

[anothervip]

GetOverlappedResult(h,&os,numberOfBytesWritten,TRUE) 把TRUE->FALSE

[wlwlxj]

看看候杰翻译的那本win32多线程，比较不错，讲的详细

[xmzh]

没有改善!a

[xmzh]

运行一段时间就返回false，谁知道怎么回事？

[steed_jet]

建议在写之前调用ClearCommError；
看看GetLastError返回的错误是什么错误根据提示再改进！

[robin_yao]

ERROR_IO_PENDING
这个本来就不是错误，表示系统还没读完，或者写完！！
BOOL GetOverlappedResult(
HANDLE hFile, // handle to file, pipe, or device
LPOVERLAPPED lpOverlapped, // overlapped structure
LPDWORD lpNumberOfBytesTransferred, // bytes transferred
BOOL bWait // wait option
);

参数
bWait
[in] Specifies whether the function should wait for the pending overlapped operation to be completed. If TRUE, the function does not return until the operation has been completed. If FALSE and the operation is still pending, the function returns FALSE and the GetLastError function returns ERROR_IO_INCOMPLETE.

[xmzh]

关键是为什么运行一段时间它就不发数据了,端点显示在这个地方,总是返回false

[一条晚起的虫]

while ( GetOverlappedResult(h,&os,numberOfBytesWritten,TRUE) == 0 ) //TRUE --> FALSE

{

dwError=GetLastError();

if( dwError == ERROR_IO_INCOMPLETE )
{
continue;
}
else
{
ClearCommError(,,);
//如果还不行，看看dwError到底是多少，根据dwError大致可以判断一下原因。
return FALSE;
}

[xmzh]

不发数据!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!