system.cpp

自己动手写操作系统源代码,不可多得的代码

//***********************************************************************/
//    Author                    : Garry
//    Original Date             : Nov,06 2004
//    Module Name               : system.cpp
//    Module Funciton           : 
//                                This module countains system mechanism releated objects's
//                                implementation..
//                                Including the following aspect:
//                                1. Interrupt object and interrupt management code;
//                                2. Timer object and timer management code;
//                                3. System level parameters management coee,such as
//                                   physical memory,system time,etc;
//                                4. Other system mechanism releated objects.
//
//                                ************
//                                This file is one of the most important file of Hello China.
//                                ************
//    Last modified Author      :
//    Last modified Date        :
//    Last modified Content     :
//                                1.
//                                2.
//    Lines number              :
//***********************************************************************/

#ifndef __STDAFX_H__
#include "..\INCLUDE\StdAfx.h"
#endif

__PERF_RECORDER  TimerIntPr = {
	U64_ZERO,
	U64_ZERO,
	U64_ZERO,
	U64_ZERO};                  //Performance recorder object used to mesure
                                //the performance of timer interrupt.

//
//TimerInterruptHandler routine.
//The following routine is the most CRITICAL routine of kernel of Hello China.
//The routine does the following:
// 1. Schedule timer object;
// 2. Update the system level variables,such as dwClockTickCounter;
// 3. Schedule kernel thread(s).
//

static BOOL TimerInterruptHandler(LPVOID lpEsp,LPVOID)
{
	DWORD                     dwPriority        = 0L;
	__TIMER_OBJECT*           lpTimerObject     = 0L;
	__KERNEL_THREAD_MESSAGE   Msg                   ;
	__PRIORITY_QUEUE*         lpTimerQueue      = NULL;
	__PRIORITY_QUEUE*         lpSleepingQueue   = NULL;
	__KERNEL_THREAD_OBJECT*   lpKernelThread    = NULL;
	DWORD                     dwFlags           = 0L;

	if(NULL == lpEsp)    //Parameter check.
		return TRUE;

	if(System.dwClockTickCounter == System.dwNextTimerTick)     //Should schedule timer.
	{
		lpTimerQueue = System.lpTimerQueue;
		lpTimerObject = (__TIMER_OBJECT*)lpTimerQueue->GetHeaderElement(
			(__COMMON_OBJECT*)lpTimerQueue,
			&dwPriority);
		if(NULL == lpTimerObject)
			goto __CONTINUE_1;
		dwPriority = MAX_DWORD_VALUE - dwPriority;
		while(dwPriority <= System.dwNextTimerTick)    //Strictly speaking,the dwPriority
			                                           //variable must EQUAL System.dw-
													   //NextTimerTick,but in the implement-
													   //ing of the current version,there
													   //may be some error exists,so we assume
													   //dwPriority equal or less than dwNext-
													   //TimerTic.
		{
			if(NULL == lpTimerObject->DirectTimerHandler)  //Send a message to the kernel thread.
			{
				Msg.wCommand = KERNEL_MESSAGE_TIMER;
				Msg.dwParam  = lpTimerObject->dwTimerID;
				KernelThreadManager.SendMessage(
					(__COMMON_OBJECT*)lpTimerObject->lpKernelThread,
					&Msg);
				//PrintLine("Send a timer message to kernel thread.");
			}
			else
			{
				lpTimerObject->DirectTimerHandler(
					lpTimerObject->lpHandlerParam);    //Call the associated handler.
			}

			switch(lpTimerObject->dwTimerFlags)
			{
			case TIMER_FLAGS_ONCE:        //Delete the timer object processed just now.
				ObjectManager.DestroyObject(&ObjectManager,
					(__COMMON_OBJECT*)lpTimerObject);
				break;
			case TIMER_FLAGS_ALWAYS:    //Re-insert the timer object into timer queue.
				dwPriority  = lpTimerObject->dwTimeSpan;
				dwPriority /= SYSTEM_TIME_SLICE;
				dwPriority += System.dwClockTickCounter;
				dwPriority  = MAX_DWORD_VALUE - dwPriority;
				lpTimerQueue->InsertIntoQueue((__COMMON_OBJECT*)lpTimerQueue,
					(__COMMON_OBJECT*)lpTimerObject,
					dwPriority);
				break;
			default:
				break;
			}

			lpTimerObject = (__TIMER_OBJECT*)lpTimerQueue->GetHeaderElement(
				(__COMMON_OBJECT*)lpTimerQueue,
				&dwPriority);    //Check another timer object.
			if(NULL == lpTimerObject)
				break;
			dwPriority = MAX_DWORD_VALUE - dwPriority;
		}

		if(NULL == lpTimerObject)  //There is no timer object in queue.
		{
			__ENTER_CRITICAL_SECTION(NULL,dwFlags);
			System.dwNextTimerTick = 0L;
			__LEAVE_CRITICAL_SECTION(NULL,dwFlags);
		}
		else
		{
			__ENTER_CRITICAL_SECTION(NULL,dwFlags);
			System.dwNextTimerTick = dwPriority;    //Update the next timer tick counter.
			__LEAVE_CRITICAL_SECTION(NULL,dwFlags);
			dwPriority = MAX_DWORD_VALUE - dwPriority;
			lpTimerQueue->InsertIntoQueue((__COMMON_OBJECT*)lpTimerQueue,
				(__COMMON_OBJECT*)lpTimerObject,
				dwPriority);
		}
	}

__CONTINUE_1:

	//
	//The following code wakes up all kernel thread(s) whose status is SLEEPING and
	//the time it(then) set is out.
	//
	if(System.dwClockTickCounter == KernelThreadManager.dwNextWakeupTick)  //There must existes
		                                                                   //kernel thread(s) to
																		   //be wake up.
	{
		lpSleepingQueue = KernelThreadManager.lpSleepingQueue;
		lpKernelThread  = (__KERNEL_THREAD_OBJECT*)lpSleepingQueue->GetHeaderElement(
			(__COMMON_OBJECT*)lpSleepingQueue,
			&dwPriority);
		while(lpKernelThread)
		{
			dwPriority = MAX_DWORD_VALUE - dwPriority;  //Now,dwPriority countains the tick
			                                            //counter value.
			if(dwPriority > System.dwClockTickCounter)
				break;    //This kernel thread should not be wake up.
			lpKernelThread->dwThreadStatus = KERNEL_THREAD_STATUS_READY;
			KernelThreadManager.AddReadyKernelThread(
				(__COMMON_OBJECT*)&KernelThreadManager,
				lpKernelThread);  //Insert the waked up kernel thread into ready queue.

			lpKernelThread = (__KERNEL_THREAD_OBJECT*)lpSleepingQueue->GetHeaderElement(
				(__COMMON_OBJECT*)lpSleepingQueue,
				&dwPriority);  //Check next kernel thread in sleeping queue.
		}
		if(NULL == lpKernelThread)
		{
			__ENTER_CRITICAL_SECTION(NULL,dwFlags);
			KernelThreadManager.dwNextWakeupTick = 0L;
			__LEAVE_CRITICAL_SECTION(NULL,dwFlags);
		}
		else
		{
			__ENTER_CRITICAL_SECTION(NULL,dwFlags);
			KernelThreadManager.dwNextWakeupTick = dwPriority;
			__LEAVE_CRITICAL_SECTION(NULL,dwFlags);
			dwPriority = MAX_DWORD_VALUE - dwPriority;
			lpSleepingQueue->InsertIntoQueue((__COMMON_OBJECT*)lpSleepingQueue,
				(__COMMON_OBJECT*)lpKernelThread,
				dwPriority);
		}
	}

	goto __TERMINAL;

__TERMINAL:
	__ENTER_CRITICAL_SECTION(NULL,dwFlags);
	System.dwClockTickCounter ++;    //Update the system clock interrupt counter.
	__LEAVE_CRITICAL_SECTION(NULL,dwFlags);

	//KernelThreadManager.ScheduleFromInt((__COMMON_OBJECT*)&KernelThreadManager,
	//	lpEsp);

	return TRUE;
}


//
//The implementation of ConnectInterrupt routine of Interrupt Object.
//The routine do the following:
// 1. Insert the current object into interrupt object array(maintenanced by system object);
// 2. Set the object's data members correctly.
//

__COMMON_OBJECT* BOOL ConnectInterrupt(__COMMON_OBJECT*     lpThis,
							 __INTERRUPT_HANDLER  lpInterruptHandler,
							 LPVOID               lpHandlerParam,
							 UCHAR                ucVector,
							 UCHAR                ucReserved1,
							 UCHAR                ucReserved2,
							 UCHAR                ucInterruptMode,
							 BOOL                 bIfShared,
							 DWORD                dwCPUMask)
{
	__INTERRUPT_OBJECT*      lpInterrupt          = NULL;
	__INTERRUPT_OBJECT*      lpObjectRoot         = NULL;
	__SYSTEM*                lpSystem             = NULL;
	DWORD                    dwFlags              = 0L;

	if((NULL == lpThis) || (NULL == lpInterruptHandler))    //Parameters valid check.
		return NULL;

	if(ucVector >= MAX_INTERRUPT_VECTOR)                    //Impossible!!!
		return NULL;

	lpInterrupt = (__INTERRUPT_OBJECT*)
		ObjectManager.CreateObject(&ObjectManager,NULL,OBJECT_TYPE_INTERRUPT);
	if(NULL == lpInterrupt)    //Failed to create interrupt object.
		return FALSE;
	if(!lpInterrupt->Initialize((__COMMON_OBJECT*)lpInterrupt))  //Failed to initialize.
		return FALSE;

	lpInterrupt->lpPrevInterruptObject = NULL;
	lpInterrupt->lpNextInterruptObject = NULL;
	lpInterrupt->InterruptHandler      = lpInterruptHandler;
	lpInterrupt->lpHandlerParam        = lpHandlerParam;
	lpInterrupt->ucVector              = ucVector;

	__ENTER_CRITICAL_SECTION(NULL,dwFlags);
	lpObjectRoot = lpSystem->lpInterruptVector[ucVector];
	if(NULL == lpObjectRoot)    //If this is the first interrupt object of the vector.
	{
		System.lpInterruptVector[ucVector]  = lpInterrupt;
	}
	else
	{
		lpInterrupt->lpNextInterruptObject  = lpObjectRoot;
		lpObjectRoot->lpPrevInterruptObject = lpInterrupt;
		System.lpInterruptVector[ucVector]  = lpInterrupt;
	}
	//LEAVE_CRITICAL_SECTION();
	__LEAVE_CRITICAL_SECTION(NULL,dwFlags);

	return (__COMMON_OBJECT*)lpInterrupt;
}

//
//The implementation of DisconnectInterrupt.
//

static VOID DisconnectInterrupt(__COMMON_OBJECT* lpThis,
								__COMMON_OBJECT* lpInterrupt)
{
	__INTERRUPT_OBJECT*   lpIntObject    = NULL;
	__SYSTEM*             lpSystem       = NULL;
	UCHAR                 ucVector       = NULL;
	DWORD                 dwFlags        = 0L;

	if((NULL == lpThis) || (NULL == lpInterrupt)) //Parameters check.
		return;

	lpSystem = (__SYSTEM*)lpThis;
	lpIntObject = (__INTERRUPT_OBJECT*)lpInterrupt;
	ucVector    = lpIntObject->ucVector;

	//ENTER_CRITICAL_SECTION();
	__ENTER_CRITICAL_SECTION(NULL,dwFlags);
	if(NULL == lpIntObject->lpPrevInterruptObject)  //This is the first interrupt object.
	{
		lpSystem->lpInterruptVector[ucVector] = lpIntObject->lpNextInterruptObject;
		if(NULL != lpIntObject->lpNextInterruptObject) //Is not the last object.
		{
			lpIntObject->lpNextInterruptObject->lpPrevInterruptObject = NULL;
		}
	}
	else    //This is not the first object.
	{
		lpIntObject->lpPrevInterruptObject->lpNextInterruptObject = lpIntObject->lpNextInterruptObject;
		if(NULL != lpIntObject->lpNextInterruptObject)
		{
			lpIntObject->lpNextInterruptObject->lpPrevInterruptObject = lpIntObject->lpPrevInterruptObject;
		}
	}
	//LEAVE_CRITICAL_SECTION();
	__LEAVE_CRITICAL_SECTION(NULL,dwFlags);
	return;
}

//
//The implementation of Initialize routine of interrupt object.
//

BOOL InterruptInitialize(__COMMON_OBJECT* lpThis)
{
	__INTERRUPT_OBJECT*    lpInterrupt = NULL;

	if(NULL == lpThis)
		return FALSE;

	lpInterrupt = (__INTERRUPT_OBJECT*)lpThis;
	lpInterrupt->lpPrevInterruptObject = NULL;
	lpInterrupt->lpNextInterruptObject = NULL;
	lpInterrupt->InterruptHandler      = NULL;
	lpInterrupt->lpHandlerParam        = NULL;
	lpInterrupt->ucVector              = 0L;
	return TRUE;
}

//
//The implementation of Uninitialize of interrupt object.
//This routine does nothing.
//

VOID InterruptUninitialize(__COMMON_OBJECT* lpThis)
{
	return;
}


//
//The implementation of timer object.
//

BOOL TimerInitialize(__COMMON_OBJECT* lpThis)    //Initializing routine of timer object.
{
	__TIMER_OBJECT*     lpTimer  = NULL;
	
	if(NULL == lpThis)
		return FALSE;

	lpTimer = (__TIMER_OBJECT*)lpThis;
	lpTimer->dwTimerID    = 0L;
	lpTimer->dwTimeSpan   = 0L;
	lpTimer->lpKernelThread      = NULL;
	lpTimer->lpHandlerParam      = NULL;
	lpTimer->DirectTimerHandler  = NULL;

	return TRUE;
}

//
//Uninitializing routine of timer object.
//

VOID TimerUninitialize(__COMMON_OBJECT* lpThis)
{
	return;
}

//-----------------------------------------------------------------------------------
//
//              The implementation of system object.
//
//------------------------------------------------------------------------------------

//
//Initializing routine of system object.
//The routine do the following:
// 1. Create a priority queue,to be used as lpTimerQueue,countains the timer object;
// 2. Create an interrupt object,as TIMER interrupt object;
// 3. Initialize system level variables,such as dwPhysicalMemorySize,etc.
//

static BOOL SystemInitialize(__COMMON_OBJECT* lpThis)
{
	__SYSTEM*            lpSystem         = NULL;
	__PRIORITY_QUEUE*    lpPriorityQueue  = NULL;
	__INTERRUPT_OBJECT*  lpIntObject      = NULL;
	BOOL                 bResult          = FALSE;
	DWORD                dwFlags          = 0L;

	if(NULL == lpThis)
		return FALSE;

	lpSystem = (__SYSTEM*)lpThis;
	lpPriorityQueue = (__PRIORITY_QUEUE*)ObjectManager.CreateObject(&ObjectManager,
		NULL,
		OBJECT_TYPE_PRIORITY_QUEUE);

	if(NULL == lpPriorityQueue)  //Failed to create priority queue.
		return FALSE;

	if(!lpPriorityQueue->Initialize((__COMMON_OBJECT*)lpPriorityQueue))  //Failed to initialize
		                                                                 //priority queue.
		goto __TERMINAL;
	lpSystem->lpTimerQueue = lpPriorityQueue;

	lpIntObject = (__INTERRUPT_OBJECT*)ObjectManager.CreateObject(
		&ObjectManager,
		NULL,
		OBJECT_TYPE_INTERRUPT);
	if(NULL == lpIntObject)
		goto __TERMINAL;

	bResult = lpIntObject->Initialize((__COMMON_OBJECT*)lpIntObject);
	if(!bResult)
		goto __TERMINAL;

	lpIntObject->ucVector = INTERRUPT_VECTOR_TIMER;
	lpIntObject->lpHandlerParam = NULL;
	lpIntObject->InterruptHandler = TimerInterruptHandler;