使用信标对象实现线程同步

使用信标对象实现线程同步
信标对象也属于系统内核对象之一，它包含有计数，当使用计数为0时，信标对象处于无信号状态；
当使用计数大于0时，信标计数处于有信号状态。
相关函数：
CreateSemaphore:用于创建一个信标对象
HANDLE CreateSemaphore(LPSECURITY_ATTRIBUTES lpSemaphoreAttributes,LONG lInitialCount,LONG lMaxinumCount,LPCTSTR lpName);
lpSemaphoreAttributes:表示安全属性，可以是NULL
lInitialCount：初始计数
lMaxinumCount：最大计数
lpName：信标名称
ReleaseSemaphore：用于递增信号量的使用计数
BOOL ReleaseSemaphore(HANDLE hSemphore,LONG lReleaseCount,LPLONG lpPreviousCount)
hSemphore:句柄
lReleaseCount信标的递增数量
lpPreviousCount：用于返回之前的信标的使用计数
示例：
UINT output11(LPVOID pThreadParam)
{
CString text;
CAccessConflictDlg *pdlg=(CAccessConflictDlg *)pThreadParam;
long nCount=0;
while(pdlg->m_count<=100)
{
WaitForSingleObject(pdlg->m_semaphore,INFINITE);//等待信标对象有信号
text.Format("线程一输出%d",pdlg->m_count);
pdlg->m_count++;
pdlg->m_list.AddString(text);
Sleep(100);
ReleaseSemaphore(pdlg->m_semaphore,1,&nCount);
}
return 0;
}
UINT output22(LPVOID pThreadParam)
{
CString text;
CAccessConflictDlg *pdlg=(CAccessConflictDlg *)pThreadParam;
long nCount=0;
while(pdlg->m_count<=100)
{
WaitForSingleObject(pdlg->m_semaphore,INFINITE);//等待信标对象有信号
text.Format("线程二输出%d",pdlg->m_count);
pdlg->m_count++;
pdlg->m_list.AddString(text);
Sleep(100);
ReleaseSemaphore(pdlg->m_semaphore,1,&nCount);
}
return 0;
}
void CAccessConflictDlg::OnButton1()
{
m_semaphore=CreateSemaphore(NULL,1,100,"sem");
output1=AfxBeginThread(output11,this,0,0,0,NULL);
output2=AfxBeginThread(output22,this,0,0,0,NULL);
CloseHandle(output1->m_hThread);
CloseHandle(output2->m_hThread);
// TODO: Add your control notification handler code here

}