Windows程式設計 讀書筆記 – 多線程

一、多線程體繫結構

　　主線程建立程式所需要的所有視窗，並包括所有的視窗過程，以便處理這些視窗的所有訊息；其他線程只進行一些幕後處理，除了與主線程進行通訊，他們不與使用者進行交流。

　　超過1/10秒的事件(大作業，如拼字檢測、資料庫排序、列印)不應該放在訊息佇列中，而應該放在單獨的線程中處理。

　　線上程終止時，線程建立的資源不會自動釋放。

 

二、多線程API：

　　hThread = CreateThread(...)

　　DWORD WINAPI ThreadProc([PVOID pParam)

 

　　_beginthread(...)

　　void __cdecl ThreadProc(void* pParam)///在此函數結尾一般有_endthread();

 

　　ResumeThread　　//恢複線程

 

　　Sleep(0)//線程交出尚未完成的時間片。

 

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//臨界區	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//事件對象	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.

=================

 

註解。

臨界區，任意時刻只有一個線程可以進入臨界區：

init:　　　　BOOL isused = false; //表示沒線程進入臨界區

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

leave:　　　 isused = false;

臨界區只能用於同一進程內不同線程間的協調。不同進程間的協調，要用互斥。

 

事件對象的用法：

初始化

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

beginthread (Thread, 0, &params) ;

線程函數：

void Thread (PVOID pvoid)
{

　　 hEvent = ...//從pvoid中獲得
     while (TRUE)
     {
          WaitForSingleObject (hEvent, INFINITE) ;         
　　　　　//。。。。。。。。。。主體
     }
}

開始執行：

SetEvent (hEvent) ;