Windows core programming --- thread Creation

In windows core programming, a process is submitted as a thread container and provides space for thread execution. It does not perform any operations.

The WINODWS system provides the following APIs for creating threads.

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HANDLE CreateThread (
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LPSECURITY_ATTRIBUTES lpThreadAttributes, // pointer to security attributes
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DWORD dwStackSize, // initial thread stack size
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LPTHREAD_START_ROUTINE lpStartAddress, // pointer to thread function
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LPVOID lpParameter, // argument for new thread
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DWORD dwCreationFlags, // creation flags
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LPDWORD lpThreadId // pointer to receive thread ID
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);
However, developers generally do not use this API to create threads. Instead, they use the _ beginthreadex function. If MFC is used, AfxBeginThread can be used to create a thread.

 

The process of creating a thread is as follows:

 

 

After the thread kernel object is created, it starts to allocate the thread's stack memory, which is allocated from the space of the process. Therefore, the thread does not have its own memory space. The system writes pvParam and pfnStartAddrj to the stack of the thread.

Each thread has its own set of c p u registers, that is, the context of the thread. This context reflects the status of the c p u register of the thread during the last running of the thread. The c p u registers of threads are stored in a c o n t e x t structure (defined in the Wi n n t. h header file. The c o n t e x t structure itself is contained in the kernel object of the thread. When the thread is scheduled again, the thread can continue to be executed by reading the context.

 

The previous simple example shows how to create a windows Thread.

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# Include <stdio. h>
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# Include <string>
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# Include <windows. h>
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# Include <process. h>
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# Include <iostream>
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Using namespace std;
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08
 
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Class ThreadX
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{
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Private:
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Int loopStart;
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Int loopEnd;
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Int dispFrequency;
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Public:
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String threadName;
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ThreadX (int startValue, int endValue, int frequency)
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{
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LoopStart = startValue;
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LoopEnd = endValue;
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DispFrequency = frequency;
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}
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Static unsigned _ stdcall ThreadStaticEntryPoint (void * pThis)
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{
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ThreadX * pthX = (ThreadX *) pThis;
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Printf ("loopStart: % d, loopEnd: % d, dispFrequency: % d \ n", pthX-> loopStart,
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PthX-> loopEnd,
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PthX-> dispFrequency );
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Int I = 0;
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For (I = pthX-> loopStart; I <pthX-> loopEnd; I + = pthX-> dispFrequency)
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{
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Printf ("I = % d \ n", I );
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}
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Return 1; // the thread exit code
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}
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};
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Int main ()
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{
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ThreadX * threadX1 = new ThreadX (0,100, 5 );
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HANDLE hThread1;
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Unsigned uiThread1ID;
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HThread1 = (HANDLE) _ beginthreadex (NULL, // security
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0, // stack size
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ThreadX: ThreadStaticEntryPoint,
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ThreadX1, // arg list
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Create_suincluded, // so we can later call ResumeThread ()
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& UiThread1ID );
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If (hThread1 = 0)
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Printf ("Failed to create thread 1 \ n ");
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ThreadX1-> threadName = "thread1 ";
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ResumeThread (hThread1 );
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WaitForSingleObject (hThread1, INFINITE );
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CloseHandle (hThread1 );
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Delete threadX1;
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ThreadX1 = NULL;
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Printf ("Primary thread terminating. \ n ");
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System ("pause ");
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}

Author: "The blog of West Kunlun"