/************************************************************************
INTERRUPT_HANDLER
When the Z502 gets a hardware interrupt, it transfers control to
this routine in the OS.
************************************************************************/
void interrupt_handler( void ) {
INT32 device_id;
INT32 status;
INT32 Time;
INT32 Index = 0;
static BOOL remove_this_in_your_code = TRUE; /** TEMP **/
static INT32 how_many_interrupt_entries = 0; /** TEMP **/
// Get cause of interrupt
MEM_READ(Z502InterruptDevice, &device_id );
// Set this device as target of our query
MEM_WRITE(Z502InterruptDevice, &device_id );
// Now read the status of this device
MEM_READ(Z502InterruptStatus, &status );
switch(device_id)
{
case TIMER_ITR:
CALL(MEM_READ(Z502ClockStatus, &Time));
while(timerHead!=NULL)
{
if(Time>(timerHead->p_time))
{
printf("Interrupt_handler: Found device ID %d\n",timerHead->p_id);
lockTimer();
//overTimeModify();
makeTimerToReady(timerHead);
addToReadyQ(makeTimer);
unlockTimer();
}
else
break;
}
break;
}
MEM_WRITE(Z502InterruptClear, &Index );
} /* End of interrupt_handler */
void svc( SYSTEM_CALL_DATA *SystemCallData ) {
short call_type;
static short do_print = 10;
short i;
INT32 Time;
static long SleepTimer;
INT32 atLock = -1;
call_type = (short)SystemCallData->SystemCallNumber;
if ( do_print > 0 ) {
printf( "SVC handler: %s\n", call_names[call_type]);
for (i = 0; i < SystemCallData->NumberOfArguments - 1; i++ ){
//Value = (long)*SystemCallData->Argument[i];
printf( "Arg %d: Contents = (Decimal) %8ld, (Hex) %8lX\n", i,
(unsigned long )SystemCallData->Argument[i],
(unsigned long )SystemCallData->Argument[i]);
}
do_print--;
}
switch (call_type){
//get time service call
case SYSNUM_GET_TIME_OF_DAY: //This value is found in syscalls.h
CALL(MEM_READ( Z502ClockStatus, &Time ));
*SystemCallData->Argument[0] = Time;
break;
//terminate system call
case SYSNUM_TERMINATE_PROCESS:
CALL(MEM_READ( Z502ClockStatus, &Time ));
if(SystemCallData->Argument[0] == -1)
{
if(current_PCB_PTR->p_id==0)
{
CALL(Z502Halt());
break;
}
else
if(timerHead != NULL)
{
if(Time>TimerStatusTime)
{
start_timer(5);
CALL(Dispatcher());
break;
}
else
CALL(Dispatcher());
break;
}
else{
CALL(Dispatcher());
break;}
break;
}
else if(SystemCallData->Argument[0] == -2)
{
*SystemCallData->Argument[1] = ERR_SUCCESS;
CALL(Z502Halt());
break;
}
else
{
S_PCB *temp = readyHead;
S_PCB *prev = NULL;
while(temp != NULL)
{
if(temp->p_id ==SystemCallData->Argument[0])
{
if(temp->next == NULL)
{
*SystemCallData->Argument[1] = ERR_SUCCESS;
break;
}
else
{
*SystemCallData->Argument[1] = ERR_SUCCESS;
prev->next = temp->next;
break;
}
}
else
{
prev = temp;
temp = temp->next;
*SystemCallData->Argument[1] = ERR_SUCCESS;
break;
}
}
if(temp == NULL)
{
*SystemCallData->Argument[1] = CANNOTTERMINATE ;
}
}
break;
case SYSNUM_SLEEP:
//overTimeModify();
schedular_printer(SLEEP);
SleepTimer = SystemCallData->Argument[0];
CALL(MEM_READ( Z502ClockStatus, &Time ));
current_PCB_PTR->p_time = Time + SleepTimer;
lockTimer();
CALL(addToTimerQ(current_PCB_PTR));
unlockTimer();
if(Time<(timerHead->p_time)) //compare the wake time with current time
{
CALL(start_timer(SleepTimer));
CALL(Dispatcher());
}
else{ //if wake time is smaller than now, it need wake up immedately
CALL(start_timer(5));
CALL(Dispatcher());
}
break;
case SYSNUM_CREATE_PROCESS:
os_create_process(SystemCallData->Argument[0], SystemCallData->Argument[1],SystemCallData->Argument[2],SystemCallData->Argument[3],SystemCallData->Argument[4],NOTRUN);
break;
case SYSNUM_GET_PROCESS_ID:
os_get_process_id(SystemCallData->Argument[0], SystemCallData->Argument[1],SystemCallData->Argument[2]);
break;
case SYSNUM_SUSPEND_PROCESS:
os_suspend_process(SystemCallData->Argument[0], SystemCallData->Argument[1]);
break;
case SYSNUM_RESUME_PROCESS:
os_resume_process(SystemCallData->Argument[0], SystemCallData->Argument[1]);
break;
case SYSNUM_CHANGE_PRIORITY:
os_change_priority(SystemCallData->Argument[0], SystemCallData->Argument[1],SystemCallData->Argument[2]);
break;
case SYSNUM_SEND_MESSAGE:
os_send_message(SystemCallData->Argument[0], SystemCallData->Argument[1],SystemCallData->Argument[2],SystemCallData->Argument[3]);
break;
case SYSNUM_RECEIVE_MESSAGE:
os_receive_message(SystemCallData->Argument[0], SystemCallData->Argument[1],SystemCallData->Argument[2],SystemCallData->Argument[3],SystemCallData->Argument[4],SystemCallData->Argument[5]);
break;
default:
printf( "ERROR! Call type not reconginzed!\n");
printf( "Call_type is - %i\n", call_type);
}
}
void svc(SYSTEM_CALL_DATA *SystemCallData) {
short call_type;
static short do_print = 10;
short i;
//for hardware interface
MEMORY_MAPPED_IO mmio;
//for GET_TIME_OF_DAY
INT32 Temp_Clock;
//for SLEEP
long Sleep_Time;
struct Process_Control_Block *sleepPCB;
//for RESTART_PROCESS
long PID_restart;
struct Process_Control_Block *restartPCB;
struct Process_Control_Block *recreatedPCB;
//for CREATE_PROCESS
struct Process_Control_Block *newPCB;
//for TERMINATE_PROCESS
long termPID;
struct Process_Control_Block *termPCB;
//for GET_PROCESS_ID
int ReturnedPID;
char* ProcessName;
struct Process_Control_Block *PCBbyProcessName;
//for SUSPEND_PROCESS
int suspendPID;
struct Process_Control_Block *suspendPCB;
//for RESUME_PROCESS
int resumePID;
struct Process_Control_Block *resumePCB;
//for CHANGE_PRIORITY
int changePrioPID;
struct Process_Control_Block *changePrioPCB;
int newPriority;
//for SEND_MESSAGE
long TargetPID;
char *MessageBuffer;
long SendLength;
struct Message *MessageCreated;
long *ErrorReturned_SendMessage;
//for RECEIVE_MESSAGE
long SourcePID;
char *ReceiveBuffer;
long ReceiveLength;
long *ActualSendLength;
long *ActualSourcePID;
long *ErrorReturned_ReceiveMessage;
struct Process_Control_Block *Mess_PCB;
call_type = (short) SystemCallData->SystemCallNumber;
if (do_print > 0) {
printf("SVC handler: %s\n", call_names[call_type]);
for (i = 0; i < SystemCallData->NumberOfArguments - 1; i++) {
//Value = (long)*SystemCallData->Argument[i];
printf("Arg %d: Contents = (Decimal) %8ld, (Hex) %8lX\n", i,
(unsigned long) SystemCallData->Argument[i],
(unsigned long) SystemCallData->Argument[i]);
}
do_print--;
}
switch (call_type) {
//get and return current system time
case SYSNUM_GET_TIME_OF_DAY:
mmio.Mode = Z502ReturnValue;
mmio.Field1 = mmio.Field2 = mmio.Field3 = 0;
MEM_READ(Z502Clock, &mmio);
Temp_Clock = mmio.Field1;
*SystemCallData->Argument[0] = Temp_Clock;
break;
//create a new PCB and put it into pcb table and ready queue
case SYSNUM_CREATE_PROCESS:
//create a new PCB
newPCB = OSCreateProcess(SystemCallData->Argument[0], SystemCallData->Argument[1],
SystemCallData->Argument[2], SystemCallData->Argument[3],
SystemCallData->Argument[4]);
//if create successfully, put it into PCB table and ready queue
if (newPCB != NULL) {
SchedularPrinter("Create", newPCB->ProcessID);//print states
enPCBTable(newPCB);
enReadyQueue(newPCB);
}
break;
//return PID regarding process name
case SYSNUM_GET_PROCESS_ID:
ProcessName = (char*)SystemCallData->Argument[0];
//if no input process name, return the current running PID
if (strcmp(ProcessName, "") == 0) {
PCBbyProcessName = CurrentPCB();
*SystemCallData->Argument[1] = PCBbyProcessName->ProcessID;
*SystemCallData->Argument[2] = ERR_SUCCESS;
}
//find the PCB in PCB table and return PID if found
else {
PCBbyProcessName = findPCBbyProcessName(ProcessName);
//if found, return PID
if (PCBbyProcessName != NULL) {
ReturnedPID = PCBbyProcessName->ProcessID;
*SystemCallData->Argument[1] = ReturnedPID;
*SystemCallData->Argument[2] = ERR_SUCCESS;
}
//if not found, return error
else {
*SystemCallData->Argument[2] = ERR_BAD_PARAM;
}
}
break;
//if a PCB wanna sleep, put itself into timer queue and start
//a new PCB
case SYSNUM_SLEEP:
//print states
SchedularPrinter("Sleep", CurrentPID());
//Calculate WakeUpTime for PCB
Sleep_Time = (long)SystemCallData->Argument[0];
sleepPCB = CurrentPCB();
sleepPCB->WakeUpTime = CurrentTime() + Sleep_Time;
//Put current running PCB into timer queue and reset time
lockTimer();
enTimerQueue(sleepPCB);
if (sleepPCB == timerQueue->First_Element->PCB){
SetTimer(Sleep_Time);
}
unlockTimer();
//in uniprocessor, start a new PCB
//in multiprocessor, only suspend itself
if (ProcessorMode == Uniprocessor) {
//first PCB in Ready Queue starts
Dispatcher();
}
else {
OSSuspendCurrentProcess();
}
break;
//restart a PCB by terminate itself and created a new PCB with everything the same except PID
case SYSNUM_RESTART_PROCESS:
//initial return error
*SystemCallData->Argument[2] = ERR_BAD_PARAM;
PID_restart = (long)SystemCallData->Argument[0];
//if not restart itself
if (PID_restart != CurrentPID()){
//find restarted PCB
restartPCB = findPCBbyProcessID(PID_restart);
//if PCB found, terminate itself and create a new one
if (restartPCB != NULL){
TerminateProcess(restartPCB);
recreatedPCB = OSCreateProcess(restartPCB->ProcessName, restartPCB->TestToRun,
restartPCB->Priority, SystemCallData->Argument[1], SystemCallData->Argument[2]);
//if create successfully, put it into PCB table and ready queue
if (recreatedPCB != NULL) {
*SystemCallData->Argument[2] = ERR_SUCCESS;
SchedularPrinter("Create", recreatedPCB->ProcessID);//print states
enPCBTable(recreatedPCB);
enReadyQueue(recreatedPCB);
SchedularPrinter("Restart", restartPCB->ProcessID);
}
}
else{
*SystemCallData->Argument[2] = ERR_BAD_PARAM;
}
}
else{
*SystemCallData->Argument[2] = ERR_BAD_PARAM;
}
break;
//terminate a process
case SYSNUM_TERMINATE_PROCESS:
termPID = (long)SystemCallData->Argument[0];
//if PID = -1, terminate current running PCB
if (termPID == -1) {
if (PCBLiveNumber() > 1) {
*SystemCallData->Argument[1] = ERR_SUCCESS;
//print states
SchedularPrinter("Terminate", termPID);
//terminate current PCB
TerminateProcess(CurrentPCB());
}
else {
*SystemCallData->Argument[1] = ERR_SUCCESS;
HaltProcess();
}
}
//if PID = -2, terminate OS
if (termPID == -2) {
*SystemCallData->Argument[1] = ERR_SUCCESS;
HaltProcess();
}
//if PID positive, terminate specified PID
else {
termPCB = findPCBbyProcessID((long)SystemCallData->Argument[0]);
//if PCB found, terminate it
if (termPCB != NULL) {
*SystemCallData->Argument[1] = ERR_SUCCESS;
//if more than one PCB alive, simply terminate it
if (PCBLiveNumber() > 1) {
//print states
SchedularPrinter("Terminate", termPID);
//terminate specified PCB
TerminateProcess(termPCB);
}
//if last alive PCB, terminate OS
else {
HaltProcess();
}
}
else {
*SystemCallData->Argument[1] = ERR_BAD_PARAM;
}
}
break;
//suspend a PCB, which can be resumed
case SYSNUM_SUSPEND_PROCESS:
suspendPID = (int)SystemCallData->Argument[0];
//if PID = -1, suspend current running PCB
if (suspendPID == -1) {
//if more than one PCB alive, suspend it
if (PCBLiveNumber() > 1) {
*SystemCallData->Argument[1] = ERR_SUCCESS;
//print states
SchedularPrinter("Suspend", suspendPID);
//Suspend Current Process
SuspendProcess(CurrentPCB());
}
//if last one PCB alive, return error
else {
*SystemCallData->Argument[1] = ERR_BAD_PARAM;
}
}
//if PID positive, suspend specified PCB
else {
suspendPCB = findPCBbyProcessID((int)suspendPID);
//if PCB found
if (suspendPCB != NULL) {
//if more than one PCB alive, suspend it
if (suspendPCB->ProcessState == PCB_STATE_LIVE && PCBLiveNumber() > 1) {
*SystemCallData->Argument[1] = ERR_SUCCESS;
//print states
SchedularPrinter("Suspend", suspendPID);
//Suspend specified process
SuspendProcess(suspendPCB);
}
//if last one PCB alive, return error
else {
*SystemCallData->Argument[1] = ERR_BAD_PARAM;
}
}
else {
*SystemCallData->Argument[1] = ERR_BAD_PARAM;
}
}
break;
//resumes a previously suspended PCB
case SYSNUM_RESUME_PROCESS:
resumePID = (int)SystemCallData->Argument[0];
resumePCB = findPCBbyProcessID(resumePID);
//if PCB found
if (resumePCB != NULL) {
//if PCB is previously suspended
if (resumePCB->ProcessState == PCB_STATE_SUSPEND) {
*SystemCallData->Argument[1] = ERR_SUCCESS;
//print states
SchedularPrinter("Resume", resumePID);
//Resume specified process
ResumeProcess(resumePCB);
}
else {
*SystemCallData->Argument[1] = ERR_BAD_PARAM;
}
}
else {
*SystemCallData->Argument[1] = ERR_BAD_PARAM;
}
break;
//change the priority of a PCB
case SYSNUM_CHANGE_PRIORITY:
changePrioPID = (int)SystemCallData->Argument[0];
changePrioPCB = findPCBbyProcessID((int)changePrioPID);
newPriority = (int)SystemCallData->Argument[1];
//if legal priority
if (newPriority<=40 && newPriority>=0) {
if (changePrioPCB != NULL) {
*SystemCallData->Argument[2] = ERR_SUCCESS;
//print states
printf("Before changing Priority\n");
SchedularPrinter("ChangePrio", changePrioPID);
//if PCB in ready queue, change order in ready queue
if (changePrioPCB->ProcessLocation == PCB_LOCATION_READY_QUEUE
&& newPriority != changePrioPCB->Priority) {
changePrioPCB = deCertainPCBFromReadyQueue(changePrioPID);
changePrioPCB->Priority = newPriority;
enReadyQueue(changePrioPCB);
}
else {
changePrioPCB->Priority = newPriority;
}
//print states
printf("After changing Priority\n");
SchedularPrinter("ChangePrio", changePrioPID);
}
else {
*SystemCallData->Argument[2] = ERR_BAD_PARAM;
}
}
else {
*SystemCallData->Argument[2] = ERR_BAD_PARAM;
}
break;
//PCB stores a message in message table
case SYSNUM_SEND_MESSAGE:
TargetPID = (long)SystemCallData->Argument[0];
MessageBuffer = (char*)SystemCallData->Argument[1];
SendLength = (long)SystemCallData->Argument[2];
ErrorReturned_SendMessage = SystemCallData->Argument[3];
//create a message
MessageCreated = CreateMessage(TargetPID, MessageBuffer,
SendLength, ErrorReturned_SendMessage);
//if successfully create a message, put it into message table
if (MessageCreated != NULL) {
SchedularPrinter("SendMsg", TargetPID);
enMessageTable(MessageCreated);
}
break;
//retrive a message in message table
case SYSNUM_RECEIVE_MESSAGE:
SourcePID = (long)SystemCallData->Argument[0];
ReceiveBuffer = (char*)SystemCallData->Argument[1];
ReceiveLength = (long)SystemCallData->Argument[2];
ActualSendLength = SystemCallData->Argument[3];
ActualSourcePID = SystemCallData->Argument[4];
ErrorReturned_ReceiveMessage = SystemCallData->Argument[5];
Mess_PCB = CurrentPCB();
Mess_PCB->ProcessState = PCB_STATE_MSG_SUSPEND;
pcbTable->Msg_Suspended_Number += 1;
//PCB kept suspended by sleep until find a message
while (findMessage(SourcePID, ReceiveBuffer, ReceiveLength,
ActualSendLength, ActualSourcePID, ErrorReturned_ReceiveMessage) == 0) {
Mess_PCB->WakeUpTime = CurrentTime() + 10;
//Put current running PCB into timer queue and reset time
enTimerQueue(Mess_PCB);
if (Mess_PCB == timerQueue->First_Element->PCB) {
SetTimer(10);
}
//first PCB in Ready Queue starts
Dispatcher();
}
Mess_PCB->ProcessState = PCB_STATE_LIVE;
pcbTable->Msg_Suspended_Number -= 1;
SchedularPrinter("ReceiveMsg", CurrentPID());
break;
default:
printf("ERROR! call_type not recognized!\n");
printf("Call_type is - %i\n", call_type);
}
} // End of svc