SuspendThread 造成程序死锁的一个例子

msdn对SuspendThread 的说明：

This function is primarily designed for use by debuggers. It is not intended to be used for thread synchronization. Calling
SuspendThread on a thread that owns a synchronization object, such as a mutex or critical section, can lead to a deadlock if the calling thread tries to obtain a synchronization object owned by a suspended thread. To avoid this situation, a
thread within an application that is not a debugger should signal the other thread to suspend itself. The target thread must be designed to watch for this signal and respond appropriately.

虽然大家都知道尽量不要在外面调用 SuspendThread 暂停线程，不要用 TerminateThread 结束线程，但是都停留在感性认识阶段，这里给出了一段示例代码，看看
SuspendThread 造成死锁的情况。

UINT AFX_CDECL ThreadTest(LPVOID pvParam)
{
while (TRUE)
{
HMODULE hHandle = ::LoadLibrary("Common.dll");
if (hHandle)
{
void *pFun = (void *)::GetProcAddress(hHandle, "doSomething");
::FreeLibrary(hHandle);
}
::Sleep(10);
}
}

void CTESTWIN2Dlg::OnOK()
{
CWinThread *pThread = AfxBeginThread(ThreadTest, (LPVOID)this,
0, 0,
CREATE_SUSPENDED);

::DuplicateHandle(::GetCurrentProcess(), pThread->m_hThread,
::GetCurrentProcess(), &m_hThread,
0, FALSE, DUPLICATE_SAME_ACCESS);
pThread->ResumeThread();
m_bIsRun = TRUE;
SetTimer(10, 10, NULL);
}

void CTESTWIN2Dlg::OnTimer(UINT nIDEvent)
{
if (m_bIsRun)
{
::SuspendThread(m_hThread);
m_bIsRun = FALSE;
HMODULE hHandle = ::LoadLibrary("TSVul.dat");
if (hHandle)
{
void *pFun = (void *)::GetProcAddress(hHandle, "MyDoSome");
::FreeLibrary(hHandle);
}
}
else
{
::ResumeThread(m_hThread);
m_bIsRun = TRUE;
}
CDialog::OnTimer(nIDEvent);
}

win32下的API基本都是线程安全的，因此API里面有很多线程同步的地方，LoadLibrary里面有一个临界区，线程函数在执行到LoadLibrary里面之后，如果刚好走到LoadLibrary的临界区里面，此时主线程的ontimer触发，将该线程挂起，ontimer继续执行，运行到LoadLibrary后，由于线程中LoadLibrary还没有从临界区出来，此时就造成主线程ontimer里面的LoadLibrary无限等待，主线程挂起。

因此不建议用suspend暂停线程，MSDN也有说明，suspend最好只在debug里面使用。

那怎么使线程挂起呢？可以使用事件等方式，用wait族函数来暂停线程