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C# 进程间通信(共享内存)

时间:2017-04-12 09:48:26      阅读:421      评论:0      收藏:0      [点我收藏+]

标签:const   adr   textbox   pen   c++   obj   ons   imp   c#   

 

进程间通信的方式有很多,常用的方式有:

  1.共享内存(内存映射文件,共享内存DLL)。

  2.命名管道和匿名管道。

  3.发送消息 

本文是记录共享内存的方式进行进程间通信,首先要建立一个进程间共享的内存地址,创建好共享内存地址后,一个进程向地址中写入数据,另外的进程从地址中读取数据。

在数据的读写的过程中要进行进程间的同步。

进程间数据同步可以有以下的方式

  1. 互斥量Mutex

  2. 信号量Semaphore

  3. 事件Event 

本文中进程间的同步采用 信号量Semaphore的方式同步思想类似于操作系统中生产者和消费者问题的处理方式。

在A进程中创建共享内存,并开启一个线程用来读取B进程向共享内存中写入的数据,定义两个信号量进行读写互斥同步 

A进程中的程序代码

Using system;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Runtime.InteropServices;

using System.Threading;

using System.Diagnostics;

 

namespace AppOne

{

    public partial class AppOneMain : Form

    {

        const int INVALID_HANDLE_VALUE = -1;

        const int PAGE_READWRITE = 0x04;

 

        [DllImport("User32.dll")]

        private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);

        [DllImport("User32.dll")]

        private static extern bool SetForegroundWindow(IntPtr hWnd);

 

        //共享内存

        [DllImport("Kernel32.dll", EntryPoint = "CreateFileMapping")]

        private static extern IntPtr CreateFileMapping(IntPtr hFile, //HANDLE hFile,

         UInt32 lpAttributes,//LPSECURITY_ATTRIBUTES lpAttributes,  //0

         UInt32 flProtect,//DWORD flProtect

         UInt32 dwMaximumSizeHigh,//DWORD dwMaximumSizeHigh,

         UInt32 dwMaximumSizeLow,//DWORD dwMaximumSizeLow,

         string lpName//LPCTSTR lpName

         );

 

        [DllImport("Kernel32.dll", EntryPoint = "OpenFileMapping")]

        private static extern IntPtr OpenFileMapping(

         UInt32 dwDesiredAccess,//DWORD dwDesiredAccess,

         int bInheritHandle,//BOOL bInheritHandle,

         string lpName//LPCTSTR lpName

         );

 

        const int FILE_MAP_ALL_ACCESS = 0x0002;

        const int FILE_MAP_WRITE = 0x0002;

 

        [DllImport("Kernel32.dll", EntryPoint = "MapViewOfFile")]

        private static extern IntPtr MapViewOfFile(

         IntPtr hFileMappingObject,//HANDLE hFileMappingObject,

         UInt32 dwDesiredAccess,//DWORD dwDesiredAccess

         UInt32 dwFileOffsetHight,//DWORD dwFileOffsetHigh,

         UInt32 dwFileOffsetLow,//DWORD dwFileOffsetLow,

         UInt32 dwNumberOfBytesToMap//SIZE_T dwNumberOfBytesToMap

         );

 

        [DllImport("Kernel32.dll", EntryPoint = "UnmapViewOfFile")]

        private static extern int UnmapViewOfFile(IntPtr lpBaseAddress);

 

        [DllImport("Kernel32.dll", EntryPoint = "CloseHandle")]

        private static extern int CloseHandle(IntPtr hObject);

 

        private Semaphore m_Write;  //可写的信号

        private Semaphore m_Read;  //可读的信号

        private IntPtr handle;     //文件句柄

        private IntPtr addr;       //共享内存地址

        uint mapLength;            //共享内存长

 

        //线程用来读取数据        

        Thread threadRed;

        public AppOneMain()

        {

            InitializeComponent();

            init();

        }   

 

       // 初始化共享内存数据 创建一个共享内存

        privatevoid init()

        {

            m_Write = new Semaphore(1, 1, "WriteMap");//开始的时候有一个可以写

            m_Read = new Semaphore(0, 1, "ReadMap");//没有数据可读

            mapLength = 1024;

            IntPtr hFile = new IntPtr(INVALID_HANDLE_VALUE);

            handle = CreateFileMapping(hFile, 0, PAGE_READWRITE, 0, mapLength, "shareMemory");

            addr = MapViewOfFile(handle, FILE_MAP_ALL_ACCESS, 0, 0, 0);

 

            //handle = OpenFileMapping(0x0002, 0, "shareMemory");

            //addr = MapViewOfFile(handle, FILE_MAP_ALL_ACCESS, 0, 0, 0);

 

            threadRed = new Thread(new ThreadStart(ThreadReceive));

            threadRed.Start();

        }

 

       // 线程启动从共享内存中获取数据信息

        private void ThreadReceive()

        {

            myDelegate myI = new myDelegate(changeTxt);

            while (true)

            {

                try

                {

                    //m_Write = Semaphore.OpenExisting("WriteMap");

                    //m_Read = Semaphore.OpenExisting("ReadMap");

                    //handle = OpenFileMapping(FILE_MAP_WRITE, 0, "shareMemory");

 

                    //读取共享内存中的数据:

                    //是否有数据写过来

                    m_Read.WaitOne();

                    //IntPtr m_Sender = MapViewOfFile(handle, FILE_MAP_ALL_ACCESS, 0, 0, 0);

                    byte[] byteStr = new byte[100];

                    byteCopy(byteStr, addr);

                    string str = Encoding.Default.GetString(byteStr, 0, byteStr.Length);

                   /////调用数据处理方法 处理读取到的数据

                    m_Write.Release();

                }

                catch (WaitHandleCannotBeOpenedException)

                {

                    continue;

                    //Thread.Sleep(0);

                }

             }

         }

        //不安全的代码在项目生成的选项中选中允许不安全代码

        static unsafe void byteCopy(byte[] dst, IntPtr src)

        {

            fixed (byte* pDst = dst)

            {

                byte* pdst = pDst;

                byte* psrc = (byte*)src;

                while ((*pdst++ = *psrc++) != ‘\0‘)

                    ;

            }

         }

     }

}

 

B进程向共享内存中写入的数据

 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Runtime.InteropServices;

using System.Threading;

 

namespace AppTwo

{

    public partial class AppTwoMain : Form

    {

        const int INVALID_HANDLE_VALUE = -1;

        const int PAGE_READWRITE = 0x04;

        //共享内存

        [DllImport("Kernel32.dll", EntryPoint = "CreateFileMapping")]

        private static extern IntPtr CreateFileMapping(IntPtr hFile, //HANDLE hFile,

         UInt32 lpAttributes,//LPSECURITY_ATTRIBUTES lpAttributes,  //0

         UInt32 flProtect,//DWORD flProtect

         UInt32 dwMaximumSizeHigh,//DWORD dwMaximumSizeHigh,

         UInt32 dwMaximumSizeLow,//DWORD dwMaximumSizeLow,

         string lpName//LPCTSTR lpName

         );

 

        [DllImport("Kernel32.dll", EntryPoint = "OpenFileMapping")]

        private static extern IntPtr OpenFileMapping(

         UInt32 dwDesiredAccess,//DWORD dwDesiredAccess,

         int bInheritHandle,//BOOL bInheritHandle,

         string lpName//LPCTSTR lpName

         );

 

        const int FILE_MAP_ALL_ACCESS = 0x0002;

        const int FILE_MAP_WRITE = 0x0002;

 

        [DllImport("Kernel32.dll", EntryPoint = "MapViewOfFile")]

        private static extern IntPtr MapViewOfFile(

         IntPtr hFileMappingObject,//HANDLE hFileMappingObject,

         UInt32 dwDesiredAccess,//DWORD dwDesiredAccess

         UInt32 dwFileOffsetHight,//DWORD dwFileOffsetHigh,

         UInt32 dwFileOffsetLow,//DWORD dwFileOffsetLow,

         UInt32 dwNumberOfBytesToMap//SIZE_T dwNumberOfBytesToMap

         );

 

        [DllImport("Kernel32.dll", EntryPoint = "UnmapViewOfFile")]

        private static extern int UnmapViewOfFile(IntPtr lpBaseAddress);

 

        [DllImport("Kernel32.dll", EntryPoint = "CloseHandle")]

        private static extern int CloseHandle(IntPtr hObject);

        private Semaphore m_Write;  //可写的信号

        private Semaphore m_Read;  //可读的信号

        private IntPtr handle;     //文件句柄

        private IntPtr addr;       //共享内存地址

        uint mapLength;            //共享内存长

 

        Thread threadRed;

 

        public AppTwoMain()

        {

            InitializeComponent();

            //threadRed = new Thread(new ThreadStart(init));

            //threadRed.Start();

            mapLength = 1024;

        }

 

        private void button1_Click(object sender, EventArgs e)

        {

            try

            {

                m_Write = Semaphore.OpenExisting("WriteMap");

                m_Read = Semaphore.OpenExisting("ReadMap");

                handle = OpenFileMapping(FILE_MAP_WRITE, 0, "shareMemory");

                addr = MapViewOfFile(handle, FILE_MAP_ALL_ACCESS, 0, 0, 0);

 

                m_Write.WaitOne();

                byte[] sendStr = Encoding.Default.GetBytes(textBox1.Text.ToString() + ‘\0‘);

                //如果要是超长的话,应另外处理,最好是分配足够的内存

                if (sendStr.Length < mapLength)

                    Copy(sendStr, addr);

               

                m_Read.Release();

            }

            catch (WaitHandleCannotBeOpenedException)

            {

                MessageBox.Show("不存在系统信号量!");

                return;

            }

        }

 

        static unsafe void Copy(byte[] byteSrc, IntPtr dst)

        {

            fixed (byte* pSrc = byteSrc)

            {

                byte* pDst = (byte*)dst;

                byte* psrc = pSrc;

                for (int i = 0; i < byteSrc.Length; i++)

                {

                    *pDst = *psrc;

                    pDst++;

                    psrc++;

                }

            }

        }

    }

}

C# 进程间通信(共享内存)

标签:const   adr   textbox   pen   c++   obj   ons   imp   c#   

原文地址:http://www.cnblogs.com/lgx5/p/6697438.html

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