//----------------------------------------------------------------------
//
// ProcessModuleInit
//
// Initialize the process module. This involves initializing all
// of the process control blocks to appropriate values (ie, free
// and available). We also need to initialize all of the queues.
//
//----------------------------------------------------------------------
void ProcessModuleInit () {
int i;
dbprintf ('p', "ProcessModuleInit: function started\n");
AQueueInit (&freepcbs);
AQueueInit(&runQueue);
AQueueInit (&waitQueue);
AQueueInit (&zombieQueue);
// For each PCB slot in the global pcbs array:
for (i = 0; i < PROCESS_MAX_PROCS; i++) {
dbprintf ('p', "Initializing PCB %d @ 0x%x.\n", i, (int)&(pcbs[i]));
// First, set the internal PCB link pointer to a newly allocated link
if ((pcbs[i].l = AQueueAllocLink(&pcbs[i])) == NULL) {
printf("FATAL ERROR: could not allocate link in ProcessModuleInit!\n");
GracefulExit();
}
// Next, set the pcb to be available
pcbs[i].flags = PROCESS_STATUS_FREE;
// Finally, insert the link into the queue
if (AQueueInsertFirst(&freepcbs, pcbs[i].l) != QUEUE_SUCCESS) {
printf("FATAL ERROR: could not insert PCB link into queue in ProcessModuleInit!\n");
GracefulExit();
}
}
// There are no processes running at this point, so currentPCB=NULL
currentPCB = NULL;
dbprintf ('p', "ProcessModuleInit: function complete\n");
}
//----------------------------------------------------------------------
//
// ProcessDestroy
//
// Destroy a process by setting its status to zombie and putting it
// on the zombie queue. The next time the scheduler is called, this
// process will be marked as free. We can't necessarily do it now
// because we might be the currently running process.
//
// NOTE: This must only be called from an interrupt or trap. However,
// it need not be followed immediately by a ProcessSchedule() because
// the process can continue running.
//
//----------------------------------------------------------------------
void ProcessDestroy (PCB *pcb) {
dbprintf('p', "Entering ProcessDestroy for 0x%x.\n", (int)pcb);
ProcessSetStatus (pcb, PROCESS_STATUS_ZOMBIE);
if (AQueueRemove(&(pcb->l)) != QUEUE_SUCCESS) {
printf("FATAL ERROR: could not remove link from queue in ProcessDestroy!\n");
exitsim();
}
if ((pcb->l = AQueueAllocLink(pcb)) == NULL) {
printf("FATAL ERROR: could not get link for zombie PCB in ProcessDestroy!\n");
exitsim();
}
if (AQueueInsertFirst(&zombieQueue, pcb->l) != QUEUE_SUCCESS) {
printf("FATAL ERROR: could not insert link into runQueue in ProcessWakeup!\n");
exitsim();
}
dbprintf('p', "Leaving ProcessDestroy for 0x%x.\n", (int)pcb);
}
//----------------------------------------------------------------------
//
// ProcessDestroy
//
// Destroy a process by setting its status to zombie and putting it
// on the zombie queue. The next time the scheduler is called, this
// process will be marked as free. We can't necessarily do it now
// because we might be the currently running process.
//
// NOTE: This must only be called from an interrupt or trap. However,
// it need not be followed immediately by a ProcessSchedule() because
// the process can continue running.
//
//----------------------------------------------------------------------
void ProcessDestroy (PCB *pcb) {
dbprintf ('p', "ProcessDestroy (%d): function started\n", GetCurrentPid());
ProcessSetStatus (pcb, PROCESS_STATUS_ZOMBIE);
if (AQueueRemove(&(pcb->l)) != QUEUE_SUCCESS) {
printf("FATAL ERROR: could not remove link from queue in ProcessDestroy!\n");
GracefulExit();
}
if ((pcb->l = AQueueAllocLink(pcb)) == NULL) {
printf("FATAL ERROR: could not get link for zombie PCB in ProcessDestroy!\n");
GracefulExit();
}
if (AQueueInsertFirst(&zombieQueue, pcb->l) != QUEUE_SUCCESS) {
printf("FATAL ERROR: could not insert link into runQueue in ProcessWakeup!\n");
GracefulExit();
}
dbprintf ('p', "ProcessDestroy (%d): function complete\n", GetCurrentPid());
}
//----------------------------------------------------------------------
//
// ProcessModuleInit
//
// Initialize the process module. This involves initializing all
// of the process control blocks to appropriate values (ie, free
// and available). We also need to initialize all of the queues.
//
//----------------------------------------------------------------------
void ProcessModuleInit () {
int i,j;
dbprintf ('p', "Entering ProcessModuleInit\n");
AQueueInit (&freepcbs);
AQueueInit (&runQueue);
AQueueInit (&waitQueue);
AQueueInit (&zombieQueue);
// For each PCB slot in the global pcbs array:
for (i = 0; i < PROCESS_MAX_PROCS; i++) {
dbprintf ('p', "Initializing PCB %d @ 0x%x.\n", i, (int)&(pcbs[i]));
// First, set the internal PCB link pointer to a newly allocated link
if ((pcbs[i].l = AQueueAllocLink(&pcbs[i])) == NULL) {
printf("FATAL ERROR: could not allocate link in ProcessModuleInit!\n");
exitsim();
}
// Next, set the pcb to be available
pcbs[i].flags = PROCESS_STATUS_FREE;
//-------------------------------------------------------
// STUDENT: Initialize the PCB's page table here.
//-------------------------------------------------------
////////////////////////////////////
// TODO3 CHANGE FOR 2 LEVEL DONE
// JSM, Set all entries of every page table to 0 (Invalid) since no pages have been allocated for any process
// and no level 2 page tables have been allocated for any processes
for (j = 0; j < MEM_L1_PAGE_TABLE_SIZE; j++)
{
pcbs[i].pagetable[j] = 0x00000000;
}
///////////////////////////////////
// Finally, insert the link into the queue
if (AQueueInsertFirst(&freepcbs, pcbs[i].l) != QUEUE_SUCCESS) {
printf("FATAL ERROR: could not insert PCB link into queue in ProcessModuleInit!\n");
exitsim();
}
}
// There are no processes running at this point, so currentPCB=NULL
currentPCB = NULL;
dbprintf ('p', "Leaving ProcessModuleInit\n");
}
