bool dataPage::initialize_next_page() {
recordid rid = calc_chunk_from_offset(write_offset_);
assert(rid.slot == 0);
DEBUG("\t\t%lld\n", (long long)rid.page);
if(rid.page >= first_page_ + page_count_) {
assert(rid.page == first_page_ + page_count_);
if(alloc_->grow_extent(1)) {
page_count_++;
} else {
return false; // The region is full
}
} else {
abort();
}
Page *p = alloc_ ? alloc_->load_page(xid_, rid.page-1) : loadPage(xid_, rid.page-1);
*is_another_page_ptr(p) = (rid.page-1 == first_page_) ? 2 : 1;
stasis_page_lsn_write(xid_, p, alloc_->get_lsn(xid_));
releasePage(p);
initialize_page(rid.page);
return true;
}
unsigned srtf_scheduler(struct process_node *p)
{
struct queue *i=NULL,*o=NULL,*d=NULL,*r=NULL;
struct queue *temp_queue=NULL;
struct process_node *temp_process=NULL;
struct burst_node *b=NULL;
time_t current_time,start_time,end_time;
unsigned flag=0;
time(&start_time);
r=initialize_ready_queue(p,r,5);
initialize_page(p,r); //initialize page number for the processes to request first page number
printf("\nReady Queue Initialized as follows: ");
display_queue(p,r);
printf("\n\nInitial Memory Map is as follows: ");
display_memory_map(p,r);
do
{
temp_queue=r;
while(temp_queue!=NULL)
{
for(temp_process=p;temp_process!=NULL;temp_process=temp_process->next)
{
if(temp_queue->pid==temp_process->pid)
break;
}
b=temp_queue->burst;
if(b->next!=NULL)
{
//CPU burst
time(¤t_time);
temp_process->waiting_time+=(current_time-temp_queue->timestamp);
temp_process->execution_time+=b->burst_duration;
r=r->next; //changed ready queue
temp_queue->timestamp=current_time;
time(¤t_time);
temp_queue->burst=b->next;
temp_queue->next=NULL;
display_task_manager(temp_process->pid,p,i,o,d,r,b->burst_duration);
sleep(b->burst_duration);
//push node to blocked queue - 3 cases
switch(b->exit_code)
{
case 0: //input blocked queue
i=insert_process_at_end_of_queue(i,temp_queue);
break;
case 1: //output blocked queue
o=insert_process_at_end_of_queue(o,temp_queue);
break;
case 2: //disk blocked queue
d=insert_process_at_end_of_queue(d,temp_queue);
handle_disk_block(p,d,temp_queue->pid, random_number(6));
display_memory_map(p,r);
break;
}
}
else
{
time(¤t_time);
temp_process->waiting_time+=(current_time-temp_queue->timestamp);
temp_process->execution_time+=b->burst_duration;
r=r->next;
display_task_manager(temp_process->pid,p,i,o,d,r,b->burst_duration);
sleep(b->burst_duration);
printf("\n***************** ");
printf("PID: %u\tProcess %s finished execution",temp_queue->pid,temp_process->name);
printf(" *****************\n");
sleep(3);
//free memory
free(temp_queue);
temp_queue=NULL;
}
r=switch_process_to_ready_queue(p,r,&i,5);
r=switch_process_to_ready_queue(p,r,&o,5);
r=switch_process_to_ready_queue(p,r,&d,5);
temp_queue=r;
}
display_task_manager(-1,p,i,o,d,r,0);
if(!isEmpty(i)||!isEmpty(o)||!isEmpty(d)||!isEmpty(r))
flag=1;
else
flag=0;
if(flag)
{
r=switch_process_to_ready_queue(p,r,&i,5);
r=switch_process_to_ready_queue(p,r,&o,5);
r=switch_process_to_ready_queue(p,r,&d,5);
}
}while(flag);
time(&end_time);
return((int)end_time-start_time);
}
void dataPage::initialize() {
initialize_page(first_page_);
}