使用关键代码段实现线程同步
关键代码段又称临界区，指的是一小段代码，在代码执行前，它需要独占某些资源。在程序中通常将多个线程同时访问某个资源的代码作为临界区。相关函数
InitializeCriticalSection:用于初始化临界区对象
void InitializeCriticalSection(LPCRITICAL_SECTION lpCriticalSection)
lpCriticalSection:表示一个临界区对象的指针
EnterCriticalSection:用于等待临界区对象的所有权
void EnterCriticalSection( LPCRITICAL_SECTION lpCriticalSection)
lpCriticalSection:表示一个临界区对象的指针
LeaveCriticalSection:表示放弃临界区对象的所有权
lpCriticalSection:表示一个临界区对象的指针
DeleteCriticalSection:表示释放临界区对象分配的资源，临界区对象不再可用
void DeleteCriticalSection(LPCRITICAL_SECTION lpCriticalSection)
lpCriticalSection:表示一个临界区对象的指针
示例：
CRITICAL_SECTION m_critical;
UINT output11(LPVOID pThreadParam)
{
CString text;
CAccessConflictDlg *pdlg=(CAccessConflictDlg *)pThreadParam;
long nCount=0;
while(pdlg->m_count<=100)
{
EnterCriticalSection(&pdlg->m_critical);//获取关键代码段的所有权
text.Format("线程一输出%d",pdlg->m_count);
pdlg->m_count++;
pdlg->m_list.AddString(text);
Sleep(100);
LeaveCriticalSection(&pdlg->m_critical);
}
return 0;
}
UINT output22(LPVOID pThreadParam)
{
CString text;
CAccessConflictDlg *pdlg=(CAccessConflictDlg *)pThreadParam;
long nCount=0;
while(pdlg->m_count<=100)
{
EnterCriticalSection(&pdlg->m_critical);//获取关键代码段的所有权
text.Format("线程二输出%d",pdlg->m_count);
pdlg->m_count++;
pdlg->m_list.AddString(text);
Sleep(100);
LeaveCriticalSection(&pdlg->m_critical);
}
return 0;
}
void CAccessConflictDlg::OnButton1()
{
//m_semaphore=CreateSemaphore(NULL,1,100,"sem");
InitializeCriticalSection(&m_critical);
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
}