ott*_*uit 5 c# delphi io named-pipes
我使用命名管道进行 C# 和 Delphi 之间的过程间通信。C# 使用该System.IO.Pipes包,而 Delphi 使用Libby's pipes.pas. 不幸的是,通信几乎是高性能的:分析显示通信占用了整个运行时间的 72%,其余的用于计算。
我找到了一个可能占用资源的问题:如果我没有在 Delphi 中显式断开发送客户端的连接,C# 根本不会接收任何数据。
FClient1.Write(msg[1], Length(msg));
FClient1.FlushPipeBuffers;
FClient1.WaitForReply(20);
FClient1.Disconnect; // disconnect to signalize C# that the writing is finished
FClient1.Connect; // connect again to prevent synchronization problems
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// Wait for a client to connect
stc.pipeServer.WaitForConnection();
while (reconnect_attempts < MAX_RECONNECT_ATTEMPTS) //
{
string tmp = sr.ReadLine();
// if result is empty, try again for <MAX_RECONNECT_ATTEMPTS> times
// so you can eliminate the chance that there's just a single empty request
while (tmp != null)// && result != tmp)
{
tmp = sr.ReadLine();
result += tmp;
}
// sleep, increment reconnect, write debugging...
}
stc.pipeServer.Close();
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尽管我猜重新连接的成本很高,但我并不完全确定。一个数据流(大约 1 / 11 kb)总共需要 130 毫秒(11kb 分别为 270 毫秒)(发送和接收)。
我的问题是:
是否有必要强制断开管道以表明客户端已完成写入?据我观察,只有在使用 libby's 发送时才需要这样做。是否还有其他可能导致性能不佳的原因?提前致谢。
另外,这里是相反的发送和接收:
stc.pipeClient.Connect();
StreamWriter sw = new StreamWriter(stc.pipeClient);
//sw.AutoFlush = true;
sw.WriteLine(msg);
sw.Flush();
stc.pipeClient.WaitForPipeDrain(); // waits for the other end to read all bytes
// neither disconnect nor dispose
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SetLength(S, Stream.Size); Stream.Read(S[1], Length(S));
FPipeBuffer := FPipeBuffer + S; { TODO 2 : switch case ID }
// if the XML is complete, i.e. ends with the closing checksum
if (IsFullMessage()) then
begin
// end reading, set flag
FIsPipeReady := true;
end
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经过大量(手动)分析后,我对这个问题提出了两个见解:
然而,我必须补充一点,我仍然有点困惑,无法判断这是真的还是我在这里处理了错误的数字。
下面是 Delphi 中 WinApi 实现的简单示例:
// setup pipes, you'll need one for each direction
// init handles with 0
CreatePipe(ReadPipe1, // hReadpipe
WritePipe1, // hWritePIpe
@SecurityAttributes, // Security
PIPE_SIZE) // Size
// setup Startupinfo
FillChar(StartupInfo, Sizeof(StartupInfo), 0);
StartupInfo.cb := Sizeof(StartupInfo);
StartupInfo.dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
StartupInfo.hStdInput := ReadPipe1;
StartupInfo.hStdOutput := WritePipe2;
StartupInfo.wShowWindow := SW_HIDE;
// CreateProcess [...]
// read
Win32Check(
ReadFile(
ReadPipe1, // source
(@outputBuffer[1])^, // buffer-pointer
PIPE_BUFFER_SIZE, // size
bytesRead, // returns bytes actually read
nil // overlapped on default
));
// send
Win32Check(
WriteFile(
WritePipe2,
(@msg[1])^, // lpBuffer - workarround to avoid type cast
NumberOfBytesToWrite,
bytesWritten, // lpNumberOfBytesWritten
nil // Overlapped
));
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