Windows程序设计 读书笔记 多线程

一、多线程体系结构

　　主线程创建程序所需要的所有窗口，并包括所有的窗口过程，以便处理这些窗口的所有消息；其他线程只进行一些后台处理，除了与主线程进行通信，他们不与用户进行交流。

　　超过1/10秒的事件(大作业，如拼写检测、数据库排序、打印)不应该放在消息队列中，而应该放在单独的线程中处理。

　　在线程终止时，线程创建的资源不会自动释放。

二、多线程API：

　　hThread = CreateThread(...)

　　DWORD WINAPI ThreadProc([PVOID pParam)

　　_beginthread(...)

　　void __cdecl ThreadProc(void* pParam)///在此函数结尾一般有_endthread();

　　ResumeThread　　//恢复线程

　　Sleep(0)//线程交出尚未完成的时间片。

三、MSDN　　

Synchronization Functions

The following functions are used in synchronization.

Asynchronous Function	Description
APCProc	An application-defined callback function used with the QueueUserAPC function.
GetOverlappedResult	Retrieves the results of an overlapped operation.
QueueUserAPC	Adds a user-mode asynchronous procedure call (APC) object to the APC queue of the specified thread.

Critical-Section Function//临界区	Description
DeleteCriticalSection	Releases all resources used by an unowned critical section object.
EnterCriticalSection	Waits for ownership of the specified critical section object.
InitializeCriticalSection	Initializes a critical section object.
InitializeCriticalSectionAndSpinCount	Initializes a critical section object and sets the spin count for the critical section.
LeaveCriticalSection	Releases ownership of the specified critical section object.
SetCriticalSectionSpinCount	Sets the spin count for the specified critical section.
TryEnterCriticalSection	Attempts to enter a critical section without blocking.

Event Function//事件对象	Description
CreateEvent	Creates or opens a named or unnamed event object.
OpenEvent	Opens an existing named event object.
PulseEvent	Sets the specified event object to the signaled state and then resets it to the nonsignaled state after releasing the appropriate number of waiting threads.
ResetEvent	Sets the specified event object to the nonsignaled state.
SetEvent	Sets the specified event object to the signaled state.

Interlocked Function	Description
InterlockedCompareExchange	Performs an atomic comparison of the specified values and exchanges the values, based on the outcome of the comparison.
InterlockedCompareExchangePointer	Performs an atomic comparison of the specified values and exchange of the values, based on the outcome of the comparison.
InterlockedDecrement	Decrements (decreases by one) the value of the specified variable and checks the resulting value.
InterlockedExchange	Atomically exchanges a pair of values.
InterlockedExchangeAdd	Performs an atomic addition of an increment value to an addend variable.
InterlockedExchangePointer	Atomically exchanges a pair of values.
InterlockedIncrement	Increments (increases by one) the value of the specified variable and checks the resulting value.

Mutex Function//互斥	Description
CreateMutex	Creates or opens a named or unnamed mutex object.
OpenMutex	Opens an existing named mutex object.
ReleaseMutex	Releases ownership of the specified mutex object.

Semaphore Function	Description
CreateSemaphore	Creates or opens a named or unnamed semaphore object.
OpenSemaphore	Opens an existing named semaphore object.
ReleaseSemaphore	Increases the count of the specified semaphore object by a specified amount.

Timer-Queue Timer Function	Description
ChangeTimerQueueTimer	Updates a timer-queue timer.
CreateTimerQueue	Creates a queue for timers.
CreateTimerQueueTimer	Creates a timer-queue timer.
DeleteTimerQueue	Deletes a timer queue.
DeleteTimerQueueEx	Deletes a timer queue.
DeleteTimerQueueTimer	Cancels a timer-queue timer.

Wait Function	Description
MsgWaitForMultipleObjects	Returns when the specified criteria for the specified objects is met.
MsgWaitForMultipleObjectsEx	Returns when the specified criteria for the specified objects is met.
RegisterWaitForSingleObject	Directs a wait thread in the thread pool to wait on the object.
SignalObjectAndWait	Allows the caller to atomically signal an object and wait on another object.
UnregisterWait	Cancels a registered wait operation.
UnregisterWaitEx	Cancels a registered wait operation.
WaitForMultipleObjects	Returns when the specified criteria for the specified objects is met.
WaitForMultipleObjectsEx	Returns when the specified criteria for the specified objects is met.
WaitForSingleObject	Returns when the specified criteria for the specified object is met.
WaitForSingleObjectEx	Returns when the specified criteria for the specified object is met.
WaitOrTimerCallback	Returns when the specified criteria is met.

Waitable Timer Function	Description
CancelWaitableTimer	Sets the specified waitable timer to the inactive state.
CreateWaitableTimer	Creates or opens a waitable timer object.
OpenWaitableTimer	Opens an existing named waitable timer object.
SetWaitableTimer	Activates the specified waitable timer.
TimerAPCProc	Application-defined timer completion routine used with the SetWaitableTimer function.

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注解。

临界区，任意时刻只有一个线程可以进入临界区：

init:　　　　BOOL isused = false; //表示没线程进入临界区

enter:　　　 while(isused){sleep(1);} isused=true;

leave:　　　 isused = false;

临界区只能用于同一进程内不同线程间的协调。不同进程间的协调，要用互斥。

事件对象的用法：

初始化

hEvent = CreateEvent (NULL, FALSE, FALSE, NULL) ;

beginthread (Thread, 0, &params) ;

线程函数：

void Thread (PVOID pvoid)
{

　　 hEvent = ...//从pvoid中获得
     while (TRUE)
     {
          WaitForSingleObject (hEvent, INFINITE) ;         
　　　　　//。。。。。。。。。。主体
     }
}

开始执行：

SetEvent (hEvent) ;