为什么ws2_32在函数调用终止之前发送不工作？ [英] why is ws2_32 send not working until after function-call terminates?

问题描述

（这个问题在WSK论坛上首次[天真]发布。） 

我是使用VC ++ 2008构建一个DLL，它使用ws2_32 函数通过TCP协议将命令发送到另一个应用程序（然后等待响应）。   DLL目前实现了一些功能，包括Connect，WriteRead和
Close。   Connect 获取套接字描述符。   WriteRead函数调用"发送"按钮（发送命令） 后跟"recv" （收到回复）。

WriteRead没有按预期工作，因为直到WriteRead终止后才发送命令。  我已尝试在"发送"之后进行5秒钟的睡眠。 （发送，睡眠（5000），recv），给予充足的时间。 
即使有延迟，在DLL WriteRead函数调用终止之前，[sent] 命令才会出现在目标应用中。  我已经尝试将套接字选项设置为TCP_NODELAY配置的ioctl用于阻塞和非阻塞模式。

显然WriteRead无法"recv"除非 "发送"在函数调用期间工作。

我的最后一个实验是在一个衍生线程（_beginthread）中调用Write（send）-logic但是到目前为止我只设法使应用程序崩溃正在调用DLL。

感谢任何帮助！

解决方案

你有一些代码吗？ ...

Hi,

(This question was first [naively] posted in the WSK forum.) 

I'm using VC++ 2008 to build a DLL which uses ws2_32 functions to send commands to another application (then waits for a response) via a TCP protocol.  The DLL currently implements a few functions, including Connect, WriteRead, and Close.  Connect gets the socket descriptor.  The WriteRead function calls "send" (sends a command) followed by "recv" (receives a response).

WriteRead isn't working as intended because the command isn't sent until immediately after WriteRead terminates.  I have experimented with putting a 5 second sleep after the "send" (send, Sleep(5000), recv), to give send plenty of time.  Even with the delay, the [sent] command doesn't appear at target app until after the DLL WriteRead function-call terminates.  I've tried setting socket options to TCP_NODELAY configured ioctl for blocking and nonblocking modes.

Obviously WriteRead isn't going to be able to "recv" a response unless "send" works during the function-call.

My last experiment was to call the Write(send)-logic in a spawned-thread (_beginthread) but so far I only manage to crash the app which is calling the DLL.

Any help is appreciated!

解决方案

do you have some code? ...

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