C# 实现 Linux 平台共享内存功能 - 示例代码与详解

在 Linux 平台上，可以使用 System V 共享内存机制来实现共享内存功能。以下是使用 C# 语言实现共享内存的示例代码：\n\ncsharp\nusing System;\nusing System.Runtime.InteropServices;\n\npublic class SharedMemory\n{\n [DllImport("librt.so", EntryPoint = "shmget")]\n private static extern int ShmGet(int key, int size, int shmflg);\n\n [DllImport("librt.so", EntryPoint = "shmat")]\n private static extern IntPtr ShmAttach(int shmid, IntPtr shmaddr, int shmflg);\n\n [DllImport("librt.so", EntryPoint = "shmdt")]\n private static extern int ShmDetach(IntPtr shmaddr);\n\n [DllImport("librt.so", EntryPoint = "shmctl")]\n private static extern int ShmControl(int shmid, int cmd, IntPtr buf);\n\n private IntPtr _sharedMemoryAddr;\n private int _sharedMemoryId;\n\n public void CreateSharedMemory(int key, int size)\n {\n // 创建共享内存\n _sharedMemoryId = ShmGet(key, size, 0666 | IPC_CREAT);\n if (_sharedMemoryId == -1)\n {\n throw new Exception("Failed to create shared memory.");\n }\n\n // 附加共享内存\n _sharedMemoryAddr = ShmAttach(_sharedMemoryId, IntPtr.Zero, 0);\n if (_sharedMemoryAddr == IntPtr.Zero)\n {\n throw new Exception("Failed to attach shared memory.");\n }\n }\n\n public void WriteData(byte[] data)\n {\n Marshal.Copy(data, 0, _sharedMemoryAddr, data.Length);\n }\n\n public byte[] ReadData(int size)\n {\n byte[] data = new byte[size];\n Marshal.Copy(_sharedMemoryAddr, data, 0, size);\n return data;\n }\n\n public void CloseSharedMemory()\n {\n // 分离共享内存\n int result = ShmDetach(_sharedMemoryAddr);\n if (result == -1)\n {\n throw new Exception("Failed to detach shared memory.");\n }\n\n // 删除共享内存\n result = ShmControl(_sharedMemoryId, IPC_RMID, IntPtr.Zero);\n if (result == -1)\n {\n throw new Exception("Failed to delete shared memory.");\n }\n }\n\n private const int IPC_CREAT = 512;\n private const int IPC_RMID = 0;\n}\n\npublic class Program\n{\n public static void Main(string[] args)\n {\n try\n {\n SharedMemory sharedMemory = new SharedMemory();\n sharedMemory.CreateSharedMemory(1234, 1024);\n\n // 写入数据\n byte[] data = new byte[] { 0x01, 0x02, 0x03 };\n sharedMemory.WriteData(data);\n\n // 读取数据\n byte[] readData = sharedMemory.ReadData(data.Length);\n Console.WriteLine("Read data: " + BitConverter.ToString(readData));\n\n sharedMemory.CloseSharedMemory();\n }\n catch (Exception ex)\n {\n Console.WriteLine("Error: " + ex.Message);\n }\n }\n}\n\n\n在上述代码中，CreateSharedMemory函数用于创建共享内存，接受两个参数：key表示共享内存的键值，size表示共享内存的大小。WriteData函数用于写入数据到共享内存，接受一个byte[]类型的参数。ReadData函数用于从共享内存中读取数据，接受一个int类型的参数表示读取的数据大小，并返回一个byte[]类型的数据。CloseSharedMemory函数用于关闭和删除共享内存。\n\n在Main函数中，首先创建一个SharedMemory对象，并调用CreateSharedMemory函数创建共享内存。然后使用WriteData函数将数据写入共享内存。接着使用ReadData函数从共享内存中读取数据，并输出到控制台。最后调用CloseSharedMemory函数关闭和删除共享内存。\n\n请注意，上述代码使用DllImport特性导入了Linux下的共享内存相关函数。为了在Linux平台上运行该代码，需要将librt.so文件放在可执行文件所在目录下。\n