Windows核心编程学习九：利用内核对象进行线程同步
注：源码为学习《Windows核心编程》的一些尝试，非原创。若能有助于一二访客，幸甚。
1.程序框架
#include "Queue.h"
#include <tchar.h>
#include <windowsx.h>
#include <StrSafe.h>
#include <process.h>
#include "resource.h"
/************************************************************************/
#define chHANDLE_DLGMSG(hWnd, message, fn) \
case (message): return (SetDlgMsgResult(hWnd, uMsg, \
HANDLE_##message((hWnd), (wParam), (lParam), (fn))))
// This macro function calls the C runtime's _beginthreadex function.
// The C runtime library doesn't want to have any reliance on Windows' data
// types such as HANDLE. This means that a Windows programmer needs to cast
// values when using _beginthreadex. Since this is terribly inconvenient,
// I created this macro to perform the casting.
typedef unsigned (__stdcall *PTHREAD_START) (void *);
#define chBEGINTHREADEX(psa, cbStackSize, pfnStartAddr, \
pvParam, dwCreateFlags, pdwThreadId) \
((HANDLE)_beginthreadex( \
(void *) (psa), \
(unsigned) (cbStackSize), \
(PTHREAD_START) (pfnStartAddr), \
(void *) (pvParam), \
(unsigned) (dwCreateFlags), \
(unsigned *) (pdwThreadId)))
// Sets the dialog box icons
inline void chSETDLGICONS(HWND hWnd, int idi)
{
SendMessage(hWnd, WM_SETICON, ICON_BIG, (LPARAM)
LoadIcon((HINSTANCE) GetWindowLongPtr(hWnd, GWLP_HINSTANCE), MAKEINTRESOURCE(idi)));
SendMessage(hWnd, WM_SETICON, ICON_SMALL, (LPARAM)
LoadIcon((HINSTANCE) GetWindowLongPtr(hWnd, GWLP_HINSTANCE), MAKEINTRESOURCE(idi)));
}
BOOL Dlg_OnInitDialog(HWND hWnd, HWND hWndFocus, LPARAM lParam)
{
chSETDLGICONS(hWnd, IDI_QUEUE);
return TRUE;
}
void Dlg_OnCommand(HWND hWnd, int id, HWND hWndCtl, UINT codeNotify)
{
switch (id)
{
case IDCANCEL:
EndDialog(hWnd, id);
break;
}
}
INT_PTR WINAPI Dlg_Proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg)
{
chHANDLE_DLGMSG(hWnd, WM_INITDIALOG, Dlg_OnInitDialog);
chHANDLE_DLGMSG(hWnd, WM_COMMAND, Dlg_OnCommand);
}
return FALSE;
}
/*************************************************************************/
int WINAPI _tWinMain(HINSTANCE hInstExe, HINSTANCE, PTSTR pszCmdLine, int)
{
DialogBox(hInstExe, MAKEINTRESOURCE(IDD_QUEUE), NULL, Dlg_Proc);
return 0;
}
2.线程安全队列的实现
/*
* File: CQueue.h
* Time: 2013-07-10
* 描述： 学习《Windows核心编程》
*/
#ifndef _CQUEUE_H_
#define _CQUEUE_H_
#include <windows.h>
class CQueue
{
public:
struct ELEMENT {
int m_nThreadNum; // 线程号
int m_nRequestNum; // 请求号
};
typedef ELEMENT* PELEMENT;
private:
PELEMENT m_pElements; // 队列元素数组
int m_nMaxElements; // 数组长度
HANDLE m_h[2]; // 两个内核对象，一个互斥量一个信号量
HANDLE &m_hmtxQ; // 互斥量对象的引用
HANDLE &m_hsemNumElements; // 信号量对象的引用
public:
CQueue(int nMaxElements);
~CQueue();
BOOL Append(PELEMENT pElement, DWORD dwMilliseconds);
BOOL Remove(PELEMENT pElement, DWORD dwMilliseconds);
};
#endif
/************************************************************************/
CQueue::CQueue(int nMaxElements) : m_hmtxQ(m_h[0]), m_hsemNumElements(m_h[1])
{
// 初始化结构数组
m_pElements = (PELEMENT)HeapAlloc(GetProcessHeap(), 0, sizeof(ELEMENT) * nMaxElements);
// 初始化数组长度
m_nMaxElements = nMaxElements;
// 创建互斥量和信号量内核对象
m_hmtxQ = CreateMutex(NULL, FALSE, NULL);
m_hsemNumElements = CreateSemaphore(NULL, 0, nMaxElements, NULL);
}
CQueue::~CQueue()
{
// 清理内核对象和内存
CloseHandle(m_hsemNumElements);
CloseHandle(m_hmtxQ);
HeapFree(GetProcessHeap(), 0, m_pElements);
}
BOOL CQueue::Append(CQueue::PELEMENT pElement, DWORD dwTimeout)
{
BOOL fOk = FALSE;
// 等待互斥量内核对象
DWORD dw = WaitForSingleObject(m_hmtxQ, dwTimeout);
// 返回WAIT_OBJECT_0表示得到了队列的独占访问权
if (dw == WAIT_OBJECT_0) {
LONG lPrevCount;
// 尝试向队列添加新元素
fOk = ReleaseSemaphore(m_hsemNumElements, 1, &lPrevCount);
// fOk为TRUE表示队列没满，可以添加新元素
if (fOk) {
m_pElements[lPrevCount] = *pElement;
}
else {
SetLastError(ERROR_DATABASE_FULL);
}
// 释放互斥量，允许其他线程访问队列
ReleaseMutex(m_hmtxQ);
}
else {
SetLastError(ERROR_TIMEOUT);
}
return fOk;
}
BOOL CQueue::Remove(CQueue::PELEMENT pElement, DWORD dwTimeout)
{
// 确保对队列具有独占访问权，且要求队列中有元素可取
// 等待信号量成功的副作用使它的计数减一，所以不需要显示调用ReleaseSemaphore()
BOOL fOk = (WaitForMultipleObjects(_countof(m_h), m_h, TRUE, dwTimeout) == WAIT_OBJECT_0);
if (fOk)
{
// 获取元素
*pElement = m_pElements[0];
// 取出索引为0 的元素，把数组中剩余元素向前挪一个位置
MoveMemory(&m_pElements[0], &m_pElements[1], sizeof(ELEMENT) * (m_nMaxElements - 1));
// 释放互斥量，允许其他线程访问队列
ReleaseMutex(m_hmtxQ);
}
else
{
SetLastError(ERROR_TIMEOUT);
}
return fOk;
}
3.客户端线程
CQueue g_q(10);
volatile LONG g_fShutdown = FALSE;
HWND g_hWnd;
// Handles to all reader/writer threads
HANDLE g_hThreads[MAXIMUM_WAIT_OBJECTS];
// Number of reader/writer threads
int g_nNumThreads = 0;
/************************************************************************/
DWORD WINAPI ClientThread(PVOID pvParam)
{
int nThreadNum = PtrToUlong(pvParam); // 线程号
HWND hWndLB = GetDlgItem(g_hWnd, IDC_CLIENT);
int nRequestNum = 0;
while (1 != InterlockedCompareExchange(&g_fShutdown, 0, 0))
{
nRequestNum++;
TCHAR sz[1024];
CQueue::ELEMENT e = { nThreadNum, nRequestNum };
// 尝试添加元素到队列
if (g_q.Append(&e, 200)) {
StringCchPrintf(sz, _countof(sz), TEXT("客户线程%d 添加元素%d"), nThreadNum, nRequestNum);
}
else {
StringCchPrintf(sz, _countof(sz), TEXT("客户线程%d 添加元素%d失败(%s)"), nThreadNum, nRequestNum,
(GetLastError() == ERROR_TIMEOUT) ? TEXT("超时") : TEXT("队列已满"));
}
ListBox_SetCurSel(hWndLB, ListBox_AddString(hWndLB, sz));
Sleep(2500);
}
return 0;
}
BOOL Dlg_OnInitDialog(HWND hWnd, HWND hWndFocus, LPARAM lParam)
{
chSETDLGICONS(hWnd, IDI_QUEUE);
g_hWnd = hWnd;
DWORD dwThreadID;
// 创建客户端线程
for (int i = 0; i < 4; i++)
g_hThreads[g_nNumThreads++] = chBEGINTHREADEX(NULL, 0, ClientThread, (PVOID)(INT_PTR) i, 0, &dwThreadID);
return TRUE;
}
4.服务器端线程
DWORD WINAPI ServerThread(PVOID pvParam)
{
int nThreadNum = PtrToUlong(pvParam);
HWND hWndLB = GetDlgItem(g_hWnd, IDC_SERVER);
while (1 != InterlockedCompareExchange(&g_fShutdown, 0, 0)) {
TCHAR sz[1024];
CQueue::ELEMENT e;
// 尝试移除元素
if (g_q.Remove(&e, 5000)) {
StringCchPrintf(sz, _countof(sz), TEXT("服务器端线程%d移除客户端线程%d放入的元素%d"), nThreadNum, e.m_nThreadNum, e.m_nRequestNum);
Sleep(2000 * e.m_nThreadNum);
}
else {
StringCchPrintf(sz, _countof(sz), TEXT("服务器端线程%d 没有元素可取"), nThreadNum);
}
ListBox_SetCurSel(hWndLB, ListBox_AddString(hWndLB, sz));
}
return 0;
}
BOOL Dlg_OnInitDialog(HWND hWnd, HWND hWndFocus, LPARAM lParam)
{
chSETDLGICONS(hWnd, IDI_QUEUE);
g_hWnd = hWnd;
DWORD dwThreadID;
// 创建客户端线程
for (int i = 0; i < 4; i++)
g_hThreads[g_nNumThreads++] = chBEGINTHREADEX(NULL, 0, ClientThread, (PVOID)(INT_PTR) i, 0, &dwThreadID);
// 创建读者线程
for (int i = 0; i < 2; i++)
g_hThreads[g_nNumThreads++] = chBEGINTHREADEX(NULL, 0, ServerThread, (PVOID)(INT_PTR) i, 0, &dwThreadID);
return TRUE;
}
int WINAPI _tWinMain(HINSTANCE hInstExe, HINSTANCE, PTSTR pszCmdLine, int)
{
DialogBox(hInstExe, MAKEINTRESOURCE(IDD_QUEUE), NULL, Dlg_Proc);
InterlockedExchange(&g_fShutdown, TRUE);
WaitForMultipleObjects(g_nNumThreads, g_hThreads, TRUE, INFINITE);
while (g_nNumThreads--)
CloseHandle(g_hThreads[g_nNumThreads]);
return 0;
}
浙公网安备 33010602011771号