//----------------------------------------------------------------------
//
// ProcessFreeResources
//
// Free the resources associated with a process. This assumes the
// process isn't currently on any queue.
//
//----------------------------------------------------------------------
void ProcessFreeResources (PCB *pcb) {
int i = 0;
int usrsp = MEM_ADDRESS_TO_PAGE(pcb->currentSavedFrame[PROCESS_STACK_USER_STACKPOINTER]);
// Allocate a new link for this pcb on the freepcbs queue
if ((pcb->l = AQueueAllocLink(pcb)) == NULL) {
printf("FATAL ERROR: could not get Queue Link in ProcessFreeResources!\n");
exitsim();
}
// Set the pcb's status to available
pcb->flags = PROCESS_STATUS_FREE;
// Insert the link into the freepcbs queue
if (AQueueInsertLast(&freepcbs, pcb->l) != QUEUE_SUCCESS) {
printf("FATAL ERROR: could not insert PCB link into freepcbs queue in ProcessFreeResources!\n");
exitsim();
}
//------------------------------------------------------------
// STUDENT: Free any memory resources on process death here.
//------------------------------------------------------------
for(i = 0; i < 5; i++) {
MemoryFreePte(pcb->pagetable[i]);
}
for(i = usrsp; i <= MEM_ADDRESS_TO_PAGE(MEM_MAX_VIRTUAL_ADDRESS); i++) {
MemoryFreePte(pcb->pagetable[i]);
}
MemoryFreePage (pcb->sysStackArea / MEM_PAGESIZE);
ProcessSetStatus (pcb, PROCESS_STATUS_FREE);
dbprintf ('p', "ProcessFreeResources: function complete\n");
}
//----------------------------------------------------------------------
//
// ProcessFreeResources
//
// Free the resources associated with a process. This assumes the
// process isn't currently on any queue.
//
//----------------------------------------------------------------------
void
ProcessFreeResources (PCB *pcb)
{
int i;
int npages;
QueueInsertLast (&freepcbs, &pcb->l);
// Free the process's memory. This is easy with a one-level page
// table, but could get more complex with two-level page tables.
npages = pcb->npages;
for (i=0; i<npages; i++)
{
MemoryFreeSharedPte(pcb, i); // *MUST* be called before calling
// MemoryFreePte. MemoryFreePte does not know
// anything about shared pages, and hence it
// might screw up big time
}
for (i = 0; i < pcb->npages; i++) {
MemoryFreePte (pcb->pagetable[i]);
}
// Free the page allocated for the system stack
MemoryFreePage (pcb->sysStackArea / MEMORY_PAGE_SIZE);
ProcessSetStatus (pcb, PROCESS_STATUS_FREE);
}
//----------------------------------------------------------------------
//
// ProcessFreeResources
//
// Free the resources associated with a process. This assumes the
// process isn't currently on any queue.
//
//----------------------------------------------------------------------
void ProcessFreeResources (PCB *pcb) {
int i = 0;
dbprintf ('p', "ProcessFreeResources: function started\n");
// Allocate a new link for this pcb on the freepcbs queue
if ((pcb->l = AQueueAllocLink(pcb)) == NULL) {
printf("FATAL ERROR: could not get Queue Link in ProcessFreeResources!\n");
GracefulExit();
}
// Set the pcb's status to available
pcb->flags = PROCESS_STATUS_FREE;
// Insert the link into the freepcbs queue
if (AQueueInsertLast(&freepcbs, pcb->l) != QUEUE_SUCCESS) {
printf("FATAL ERROR: could not insert PCB link into freepcbs queue in ProcessFreeResources!\n");
GracefulExit();
}
// Free the process's memory.
for (i = 0; i < pcb->npages; i++) {
MemoryFreePte (pcb->pagetable[i]);
}
// Free the page allocated for the system stack
MemoryFreePage (pcb->sysStackArea / MEMORY_PAGE_SIZE);
ProcessSetStatus (pcb, PROCESS_STATUS_FREE);
dbprintf ('p', "ProcessFreeResources: function complete\n");
}
//----------------------------------------------------------------------
//
// ProcessFreeResources
//
// Free the resources associated with a process. This assumes the
// process isn't currently on any queue.
//
//----------------------------------------------------------------------
void ProcessFreeResources (PCB *pcb) {
int i = 0;
uint32 page;
// Allocate a new link for this pcb on the freepcbs queue
if ((pcb->l = AQueueAllocLink(pcb)) == NULL) {
printf("FATAL ERROR: could not get Queue Link in ProcessFreeResources!\n");
exitsim();
}
// Set the pcb's status to available
pcb->flags = PROCESS_STATUS_FREE;
// Insert the link into the freepcbs queue
if (AQueueInsertLast(&freepcbs, pcb->l) != QUEUE_SUCCESS) {
printf("FATAL ERROR: could not insert PCB link into freepcbs queue in ProcessFreeResources!\n");
exitsim();
}
//------------------------------------------------------------
// STUDENT: Free any memory resources on process death here.
//------------------------------------------------------------
/////////////////////////////////////////////////////////////
// TODO CHANGE FOR 2 LEVEL Free Resource
// JSM - free all physical pages corresponding to valid page table entries in process
// AS WEL AS FREEING SYSTEM STACK PAGE ASSOCIATED WITH PROCESS
for (i = 0; i < MEM_L1_PAGE_TABLE_SIZE; i++)
{
if(pcb->pagetable[i] & MEM_PTE_VALID) // For every page currently valid in page table
{
pcb->pagetable[i] &= ~(MEM_PTE_VALID); // Invalidate page table entry
page = (pcb->pagetable[i]) / MEM_PAGE_SIZE;
dbprintf ('p', "Preparing to free physical page #%d\n", page);
MemoryFreePage(page); // Free page in freemap
}
}
dbprintf ('p', "Preparing to free physical page #%d (System Stack)\n", (pcb->sysStackArea / MEM_PAGE_SIZE) );
MemoryFreePage(pcb->sysStackArea / MEM_PAGE_SIZE); // Free page in freemap
/////////////////////////////////////////////////////////////
dbprintf ('p', "Free Resources DONE!\n\n");
//while(1);
ProcessSetStatus (pcb, PROCESS_STATUS_FREE);
}
//----------------------------------------------------------------------
//
// ProcessFreeResources
//
// Free the resources associated with a process. This assumes the
// process isn't currently on any queue.
//
//----------------------------------------------------------------------
void
ProcessFreeResources (PCB *pcb)
{
int i;
int npages;
QueueInsertLast (&freepcbs, &pcb->l);
// Free the process's memory. This is easy with a one-level page
// table, but could get more complex with two-level page tables.
//------------------------------------------
// You may change the code below
//------------------------------------------
npages = pcb->npages;
for (i = 0; i < pcb->npages; i++) {
MemoryFreePte (pcb->pagetable[i]);
}
// Free the page allocated for the system stack
MemoryFreePage (pcb->sysStackArea / MEMORY_PAGE_SIZE);
ProcessSetStatus (pcb, PROCESS_STATUS_FREE);
}
//----------------------------------------------------------------------
//
// ProcessFreeResources
//
// Free the resources associated with a process. This assumes the
// process isn't currently on any queue.
//
//----------------------------------------------------------------------
void ProcessFreeResources (PCB *pcb) {
int i,j;
uint32 entry, page;
uint32 *p;
// Allocate a new link for this pcb on the freepcbs queue
if ((pcb->l = AQueueAllocLink(pcb)) == NULL) {
printf("FATAL ERROR: could not get Queue Link in ProcessFreeResources!\n");
exitsim();
}
// Set the pcb's status to available
pcb->flags = PROCESS_STATUS_FREE;
// Insert the link into the freepcbs queue
if (AQueueInsertLast(&freepcbs, pcb->l) != QUEUE_SUCCESS) {
printf("FATAL ERROR: could not insert PCB link into freepcbs queue in ProcessFreeResources!\n");
exitsim();
}
//------------------------------------------------------------
// STUDENT: Free any memory resources on process death here.
//------------------------------------------------------------
/////////////////////////////////////////////////////////////
// TODO4 CHANGE FOR 2 LEVEL DONE
// JSM - free all physical pages corresponding to valid page table entries in process
// AS WELL AS FREEING SYSTEM STACK PAGE ASSOCIATED WITH PROCESS
for (i = 0; i < MEM_L1_PAGE_TABLE_SIZE; i++)
{
if(pcb->pagetable[i] != 0) // For every page currently valid in L1 Page Table
{
dbprintf ('p', "\nFreeing L2 PT entries from L1 PT index #%d\n", i);
dbprintf ('p', "L1P1 index #%d Contents: %d\n", i, pcb->pagetable[i]);
dbprintf ('p', "Start of corresponding L2PT Block: %d\n", (uint32)(level2_pt_block));
entry = ((pcb->pagetable[i])-(uint32)(level2_pt_block))/(sizeof(level2_pt));
dbprintf ('p', "Level2_pt_block entry for L1 PT index #%d is: %d\n\n", i, entry);
p = (uint32 *)&level2_pt_block[entry];
for (j = 0; j < MEM_L2_PAGE_TABLE_SIZE; j++)
{
if(*(p+j) & MEM_PTE_VALID) // For every page currently valid in page table
{
dbprintf ('p', "Invalidating L1_idx: %d, L2_idx:%d\n", i, j);
*(p+j) &= ~(MEM_PTE_VALID); // Invalidate page table entry
page = (*(p+j) / MEM_PAGE_SIZE);
dbprintf ('p', "Preparing to free physical page #%d\n", page);
MemoryFreePage(page); // Free page in freemap
}
}
// Invalidate L1 Page Table Entry
pcb->pagetable[i] = 0;
// FREE L2 PAGE TABLE
MemoryFreeL2PT(entry);
}
}
dbprintf ('p', "\nPreparing to free physical page #%d (System Stack)\n", (pcb->sysStackArea / MEM_PAGE_SIZE) );
MemoryFreePage(pcb->sysStackArea / MEM_PAGE_SIZE); // Free page in freemap
/////////////////////////////////////////////////////////////
dbprintf ('M', "Free Resources DONE!\n\n");
for(i=0; i<MEM_FREEMAP_SIZE_IN_WORDS; i++)
{
dbprintf('M', "Freemap Int #%d value: 0x%.8X\n", i, freemap[i]);
}
dbprintf('m', "\n");
for(i=0; i<MEM_FREEMAP_PT_SIZE_IN_WORDS; i++)
{
dbprintf('M', "freemap_pt index #%d value: 0x%.8X\n", i, pt_freemap[i]);
}
ProcessSetStatus (pcb, PROCESS_STATUS_FREE);
}
void MemoryFreePte (uint32 pte)
{
MemoryFreePage ((pte & MEM_PTE_MASK) /(MEM_PAGESIZE));
}
