Github

https://github.com/gongluck/Windows-Core-Program.git

//第10章 同步设备IO与异步设备IO.cpp: 定义应用程序的入口点。

//

#include "stdafx.h"

#include "第10章 同步设备IO与异步设备IO.h"

//可提醒IO回调

VOID WINAPI funComplete(

	_In_    DWORD dwErrorCode,

	_In_    DWORD dwNumberOfBytesTransfered,

	_Inout_ LPOVERLAPPED lpOverlapped

)

{

}

//IO完成端口工作线程

DWORD WINAPI workthread(LPVOID lpThreadParameter)

{

	DWORD NumberOfBytesTransferred;

	DWORD CompletionKey;

	OVERLAPPED* pOverlapped;

	BOOL bres = GetQueuedCompletionStatus(lpThreadParameter, &NumberOfBytesTransferred, &CompletionKey, &pOverlapped, INFINITE);

	//GetQueuedCompletionStatusEx可获取多个IO请求结果

	DWORD dres = GetLastError();

	return 0;

}

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,

                     _In_opt_ HINSTANCE hPrevInstance,

                     _In_ LPWSTR    lpCmdLine,

                     _In_ int       nCmdShow)

{

	//打开(创建)文件

	HANDLE hFile = CreateFile(TEXT("第10章 同步设备IO与异步设备IO.cpp"), GENERIC_READ|GENERIC_WRITE, FILE_SHARE_READ, nullptr, OPEN_EXISTING, 0, nullptr);

	if (hFile == INVALID_HANDLE_VALUE)

	{

		MessageBox(nullptr, TEXT("打开文件失败!"), TEXT("error"), MB_OK);

		return 0;

	}

	//文件类型

	DWORD dres = GetFileType(hFile);

	//dres == FILE_TYPE_DISK

	//文件大小

	LARGE_INTEGER li;

	BOOL bres = GetFileSizeEx(hFile, &li);//逻辑大小

	li.LowPart = GetCompressedFileSize(TEXT("第10章 同步设备IO与异步设备IO.cpp"), (DWORD*)&li.HighPart);//物理大小

	//文件指针

	li.QuadPart = 0;

	bres = SetFilePointerEx(hFile, li, nullptr, FILE_END);

	bres = SetFilePointerEx(hFile, li, &li, FILE_CURRENT);

	bres = SetEndOfFile(hFile);

	li.QuadPart = 0;

	bres = SetFilePointerEx(hFile, li, nullptr, FILE_BEGIN);

	//同步IO

	char* buf = new char[100];

	bres = ReadFile(hFile, buf, 100, &dres, nullptr);

	delete []buf;

	buf = nullptr;

	//刷新缓冲区

	bres = FlushFileBuffers(hFile);

	//CancelSynchronousIo

	//取消线程未完成的同步IO请求

	//关闭文件

	CloseHandle(hFile);

	hFile = nullptr;

	//异步IO

	HANDLE hFile2 = CreateFile(TEXT("第10章 同步设备IO与异步设备IO.cpp"), GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ, nullptr, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, nullptr);

	OVERLAPPED ol;

	ol.Offset = 1024;

	ol.OffsetHigh = 0;

	ol.hEvent = CreateEvent(nullptr, FALSE, FALSE, nullptr);

	char* buf2 = new char[1024];

	bres = ReadFile(hFile2, buf2, 1024, nullptr, &ol);//异步方式总是返回FALSE

	dres = GetLastError();

	switch (dres)

	{

	case ERROR_IO_PENDING:

		//IO请求添加成功

		//WaitForSingleObject(hFile2, INFINITE);

		WaitForSingleObject(ol.hEvent, INFINITE);

		break;

	case ERROR_INVALID_USER_BUFFER:

	case ERROR_NOT_ENOUGH_MEMORY:

		break;

	case ERROR_NOT_ENOUGH_QUOTA:

		break;

	default:

		break;

	}

	//取消队列中的IO请求

	//bres = CancelIo(hFile2);

	bres = CancelIoEx(hFile2, &ol);

	//bres = CancelIoEx(hFile2, nullptr);

	//bres = CloseHandle(hFile2);

	if (ol.hEvent != nullptr)

	{

		CloseHandle(ol.hEvent);

		ol.hEvent = nullptr;

	}

	//可提醒IO

	OVERLAPPED ol2;

	ol2.Offset = 1024;

	ol2.OffsetHigh = 0;

	ol2.hEvent = nullptr;

	dres = ReadFileEx(hFile2, buf2, 1024, &ol2, funComplete);//回调函数在同一个线程空间

	//置为可提醒状态

	//APC队列中只要有一个，线程就不会进入睡眠

	dres = SleepEx(INFINITE, TRUE);

	//WaitForSingleObjectEx

	//WaitForMultipleObjectsEx

	//SignalObjectAndWait

	//GetQueuedCompletionStatusEx

	//MsgWaitForMultipleObjectsEx

	dres = GetLastError();//WAIT_IO_COMPLETION

	//手动添加一项到APC队列

	//可以让目标线程结束睡眠

	dres = QueueUserAPC((PAPCFUNC)funComplete, GetCurrentThread(), NULL);

	//IO完成端口

	HANDLE iocp = CreateIoCompletionPort(hFile2, nullptr, 1, 2);

	HANDLE hts[2];

	for (int i = 0; i < 2; ++i)

		hts[i] = CreateThread(nullptr, 0, workthread, iocp, 0, nullptr);

	bres = PostQueuedCompletionStatus(iocp, 100, 1, &ol); //模拟发送IO请求完成

	bres = ReadFile(hFile2, buf2, 1024, nullptr, &ol2);

	dres = GetLastError();

	WaitForMultipleObjects(2, hts, TRUE, INFINITE);

	for (int i = 0; i < 2; ++i)

	{

		CloseHandle(hts[i]);

		hts[i] = nullptr;

	}

	CloseHandle(iocp);

	iocp = nullptr;

	CloseHandle(hFile2);

	hFile2 = nullptr;

	delete[]buf2;

	buf2 = nullptr;

	system("pause");

	return 0;

}