void MyThreadYield(void)
{
//printf("MyThreadYield: START ... curr_th = %d , parent_th = %d\n", curr_th->tid, curr_th->pid);
/*if(0!=getcontext(&curr_context))l
{
//printf("MyThreadYield : getcontext error... \n");
}*/
if(front==NULL)
{
//printf("No pending ready thread, invoking thread = %d , will continue to run \n", curr_th->tid);
return;
}
ucontext_t new_cnxt;
struct node * new_th=pop_q();
if(new_th == NULL)
{
//printf("MyThreadYield: ready queue is empty...continue running this thread... \n");
return;
}
new_cnxt=new_th->cnxt;
//printf("Inserting saved context to the queue : GetContext removed... \n");
struct node * tmp=insert_q(curr_th->cnxt,curr_th->tid,curr_th->pid,curr_th->join_th,curr_th->join_th_rear);
int old_th=curr_th->tid;
int old_pr=curr_th->pid;
ucontext_t old_cnxt=curr_th->cnxt;
struct join_list *old_jfront=curr_th->join_th;
struct join_list *old_jrear=curr_th->join_th_rear;
curr_th->tid=new_th->tid;
curr_th->pid=new_th->pid;
curr_th->cnxt=new_th->cnxt;
curr_th->join_th=new_th->join_th;
curr_th->join_th_rear=new_th->join_th_rear;
//printf("MyThreadYield: swap context from thread : %d ,to first ready thread : %d ... \n",tmp->tid,curr_th->tid);
//printf("MyThreadYield: swap context from =%d , to = %d which is also same as new_cnxt=%d\n ",tmp->cnxt,curr_th->cnxt,new_cnxt);
if(swapcontext(&(tmp->cnxt),&(new_th->cnxt))==-1)
{
curr_th->tid=old_th;
curr_th->pid=old_pr;
curr_th->cnxt=old_cnxt;
curr_th->join_th=old_jfront;
curr_th->join_th_rear=old_jrear;
removeNode(curr_th->tid);
//printf("MyThreadYield: swapcontext error...\n");
}
//printf("MyThreadYield: EXIT... \n\n\n");
}
void sem_signal(struct Semaphore *s)
{
lock_acquire(&s->locksem);
if(!empty_q(&s->t_q))
{
twakeup(pop_q(&s->t_q));
}
else
{
s->count++;
}
lock_release(&s->locksem);
}
void sem_signal(struct Semaphore *s) {
lock_acquire(&s->lock);
if (s->count > 0) {
s->count++;
lock_release(&s->lock);
}
else {
if (empty_q(&s->q) == 1)
s->count++;
else
twakeup(pop_q(&s->q));
lock_release(&s->lock);
}
}
void MySemaphoreWait(MySemaphore sem)
{
struct sema *passed_sem=(struct sema *)sem;
struct sema *c_sem=get_sem(passed_sem);
if(c_sem==NULL)
{
//printf("MySemaphoreWait : sem is NULL.... returning.... \n");
return;
}
//printf("MySemaphoreWait : Enter... for sem=%d \n",c_sem->sid);
if(c_sem->val>0)
{
//printf("MySemaphoreWait : resource available for c_sem=%d ...simply decrementing its value , now val=%d\n",c_sem->sid,(c_sem->val-1));
c_sem->val = (c_sem->val)-1;
}
else if(c_sem->val==0)
{
//printf(" MySemaphoreWait : c_sem->val is already 0.... add this thread into sem's sblocked list...and then....Move current thread=%d to blocked queue... \n",curr_th->tid);
// need to add curr_th into, this semaphore's FIFO blocked thread id list....
struct sb_thread *tmp=(struct sb_thread *)malloc(sizeof(struct sb_thread));
if(tmp==NULL)
{
//printf(" MySemaphoreWait : Memory not allocated...max limit reached for threads....returning gracefully...\n");
swapcontext(&dmy_cnxt,&init_cnxt);
}
tmp->sb_id=curr_th->tid;
tmp->sb_next=NULL;
//printf("MySemaphoreWait : init tmp...\n");
if(c_sem->sb_front == NULL)
{
c_sem->sb_front=tmp;
c_sem->sb_rear=tmp;
} else
{
c_sem->sb_rear->sb_next=tmp;
c_sem->sb_rear=tmp;
}
// Move current thread to blocked queue, run first ready queue, lookup MyThreadJoin for reference....
// POP first ready thread...
// todo: code to move current thread to blocked queue...
struct node * blocked_th=binsert_q(curr_th->cnxt,curr_th->tid,curr_th->pid,curr_th->join_th,curr_th->join_th_rear);
//printf("MySemaphoreWait : current thread:%d entered in BQ , but actual current thread is= %d\n",blocked_th->tid, curr_th->tid);
//saving current thread pointers for future failure recovery
int old_th=curr_th->tid;
int old_pr=curr_th->pid;
ucontext_t old_cnxt=curr_th->cnxt;
struct join_list *old_jfront=curr_th->join_th;
struct join_list *old_jrear=curr_th->join_th_rear;
//printf("MySemaphoreWait : popping first RQ thread...\n");
ucontext_t new_cnxt;
struct node * new_th=pop_q();
if(new_th == NULL)
{
//printf(" MySemaphoreWait: ready queue empty ... \n");
swapcontext(&dmy_cnxt,&init_cnxt);
}
new_cnxt=new_th->cnxt;
//updating current thread pointers
curr_th->tid=new_th->tid;
curr_th->pid=new_th->pid;
curr_th->cnxt=new_th->cnxt;
curr_th->join_th=new_th->join_th;
curr_th->join_th_rear=new_th->join_th_rear;
//printf("MySemaphoreWait: swap context from thread : %d to first ready thread : %d ... \n",old_th,curr_th->tid);
if(swapcontext(&(blocked_th->cnxt),&new_cnxt)==-1)
{
//printf("MySemaphoreWait: Blocking swapcontext error... \n");
curr_th->tid=old_th;
curr_th->pid=old_pr;
curr_th->cnxt=old_cnxt;
curr_th->join_th=old_jfront;
curr_th->join_th_rear=old_jrear;
bremoveNode(curr_th->tid);
//printf("MySemaphoreWait: Blocking swapcontext error recovery done...\n");
}
// After resuming from ready - queue,
//printf(" MySemaphoreWait: Semaphore wait over, for current thread= %d ....\n",curr_th->tid);
}
//printf(" MySemaphoreWait : EXIT .... \n");
}
/*
Terminates the invoking thread. Note: all MyThreads are required to invoke this function. Do not allow functions to “fall out” of the start function.
*/
void MyThreadExit(void)
{
//printf("MyThreadExit: START ... for thread =%d \n",curr_th->tid);
ucontext_t next_context;
//Need to check, if terminating thread's parent is in blocked queue or not ...
struct node *parent_th=bgetNode(curr_th->pid);
if(parent_th!=NULL)
{
//printf("Parent thread = %d is in blocked queue, need to check whether it is blocked by this child thread = %d \n" , parent_th->tid,curr_th->tid);
struct join_list *jtmp;
if(parent_th->join_th !=NULL)
{
if( (parent_th->join_th == parent_th->join_th_rear) && (parent_th->join_th->ch_tid == curr_th->tid))
{ // Only one element in queue, and that's the one we are looking for
//printf("Only One element in join_list, and it's a MATCH, deleting it, Queue is empty now ...\n");
jtmp=parent_th->join_th;
parent_th->join_th=NULL;
parent_th->join_th_rear=NULL;
free(jtmp);
} else if (parent_th->join_th->ch_tid == curr_th->tid)
{ // First element needs to be deleted, and Queue have more than one elements...
//printf("First element of queue is a MATCH, queue have more than one element, shifting Front pointer of join_list ...\n");
jtmp=parent_th->join_th;
parent_th->join_th=parent_th->join_th->link;
free(jtmp);
} else
{// Need to traverse through queue, to check for the element
//printf("Need to traverse through, join_list of parent thread = %d , to look for child thread = %d \n",parent_th->tid,curr_th->tid);
jtmp=parent_th->join_th;
struct join_list *jprev=NULL;
while(jtmp!=NULL && (jtmp->ch_tid != curr_th->tid))
{
jprev=jtmp;
jtmp=jtmp->link;
}
if(jtmp!=NULL && (jtmp->ch_tid == curr_th->tid))
{
//printf("Child thread =%d in join_list of parent thread=%d, removing it from list ...\n",curr_th->tid,parent_th->tid);
jprev->link=jtmp->link;
free(jtmp);
} else if(jtmp==NULL)
{
//printf("This terminating thread = %d is not blocking its parent thread= %d...\n",curr_th->tid,parent_th->tid);
}
}
//Now, if this parent thread's waiting child thread join_list becomes empty, it is ready to execute and therefore need to insert into ready queue...
if(parent_th->join_th ==NULL)
{
//printf(" Parent thread: %d , join list is empty, It is ready to execute...inserting into ready queue \n",parent_th->tid);
struct node *blocked_to_ready=insert_q(parent_th->cnxt,parent_th->tid,parent_th->pid,parent_th->join_th,parent_th->join_th_rear);
//printf(" Thread = %d moved to ready Queue \n ",blocked_to_ready->tid);
bremoveNode(parent_th->tid);
//printf(" Thread = %d removed from blocked Queue \n",blocked_to_ready->tid);
}
}
}
if(front==NULL)
{
//printf("No ready threads pending...\n");
swapcontext(&dmy_cnxt,&init_cnxt);
}
//printf("MyThreadExit: fetching first ready state ... \n");
struct node * new_th=pop_q();
if(new_th == NULL)
{
//printf(" MyThreadExit: ready queue empty ... \n");
swapcontext(&dmy_cnxt,&init_cnxt);
}
next_context=new_th->cnxt;
int old_th=curr_th->tid;
int old_pr=curr_th->pid;
ucontext_t old_cnxt=curr_th->cnxt;
struct join_list *old_jfront=curr_th->join_th;
struct join_list *old_jrear=curr_th->join_th_rear;
curr_th->tid=new_th->tid;
curr_th->pid=new_th->pid;
curr_th->cnxt=new_th->cnxt;
curr_th->join_th=new_th->join_th;
curr_th->join_th_rear=new_th->join_th_rear;
//printf("MyThreadExit : Terminating invoking thread : %d , and running next thread : %d .... \n",old_th,new_th->tid);
//printf("MyThreadExit: Thread=%d set terminated... , New thread=%d , context = %d \n",old_th,new_th->tid, new_th->cnxt);
//printf("MyThreadExit: swap context from =%d , to = %d which is also same as next_cnxt=%d\n ",old_cnxt,new_th->cnxt,next_context);
if(-1==swapcontext(&(old_cnxt),&(new_th->cnxt)))
{
//printf("MyThreadExit: setcontext error...\n");
curr_th->tid=old_th;
curr_th->pid=old_pr;
curr_th->cnxt=old_cnxt;
curr_th->join_th=old_jfront;
curr_th->join_th_rear=old_jrear;
//printf("MyThreadExit: setcontext error RECOVERY done...\n");
}
//printf("MyThreadExit: exit for thread=",curr_th->tid);
}
/*
Waits until all children have terminated. Returns immediately if there are no active children.
*/
void MyThreadJoinAll(void)
{
//printf("MyThreadJoinAll: START : for current thread : %d \n", curr_th->tid);
//printf("Need to traverse through RQ and BQ and add all children of this thread to its join_list...\n");
//saving join pointers for future failure recovery
struct join_list *old_jfront=curr_th->join_th;
struct join_list *old_jrear=curr_th->join_th_rear;
//Traverse through RQ
struct node *tmp=front;
while(tmp!=NULL)
{
if(tmp->pid == curr_th->tid)
{
//printf("Child found , thread=%d , is a child thread of current thread , need to insert into join_list\n",tmp->tid);
struct join_list *jtmp=(struct join_list *)malloc(sizeof(struct join_list));
if(jtmp==NULL)
{
//printf("No memory allocated... Maximum thread limit reached...returning gracefully...\n");
swapcontext(&dmy_cnxt,&init_cnxt);
}
jtmp->ch_tid=tmp->tid;
jtmp->link=NULL;
if((curr_th->join_th)==NULL)
{
curr_th->join_th=jtmp;
curr_th->join_th_rear=curr_th->join_th;
} else
{
curr_th->join_th_rear->link=jtmp;
curr_th->join_th_rear=jtmp;
}
}
tmp=tmp->next;
}
//Need to Traverse through BQ
//printf("MyThreadJoinAll: now Traversing BQ... \n");
tmp=bfront;
while(tmp!=NULL)
{
if(tmp->pid == curr_th->tid)
{
//printf("Child found , thread=%d , is child thread of current thread , need to insert into join_list \n",tmp->tid);
struct join_list *jtmp=(struct join_list *)malloc(sizeof(struct join_list));
if(jtmp==NULL)
{
//printf("No memory allocated... Maximum thread limit reached...returning gracefully...\n");
swapcontext(&dmy_cnxt,&init_cnxt);
}
jtmp->ch_tid=tmp->tid;
jtmp->link=NULL;
if((curr_th->join_th)==NULL)
{
curr_th->join_th=jtmp;
curr_th->join_th_rear=curr_th->join_th;
} else
{
curr_th->join_th_rear->link=jtmp;
curr_th->join_th_rear=jtmp;
}
}
tmp=tmp->next;
}
//printf("MyThreadJoinAll : Traversing queues finished... join_list updated... now move thread:%d to blocked queue and run the first ready thread \n",curr_th->tid);
//Need to move this thread into blocked Queue and run the first ready state
//Fetching first ready state
struct node * blocked_th=binsert_q(curr_th->cnxt,curr_th->tid,curr_th->pid,curr_th->join_th,curr_th->join_th_rear);
//printf("MyThreadJoinAll : current thread:%d entered in BQ \n",curr_th->tid);
int old_th=curr_th->tid;
int old_pr=curr_th->pid;
ucontext_t old_cnxt=curr_th->cnxt;
ucontext_t new_cnxt;
struct node * new_th=pop_q();
if(new_th == NULL)
{
//printf(" MyThreadJoinAll: ready queue empty ... \n");
swapcontext(&dmy_cnxt,&init_cnxt);
}
new_cnxt=new_th->cnxt;
curr_th->tid=new_th->tid;
curr_th->pid=new_th->pid;
curr_th->cnxt=new_th->cnxt;
curr_th->join_th=new_th->join_th;
curr_th->join_th_rear=new_th->join_th_rear;
//printf("MyThreadJoinAll: swap context from thread : %d to first ready thread : %d... \n",old_th,curr_th->tid);
if(swapcontext(&(blocked_th->cnxt),&new_cnxt)==-1)
{
curr_th->tid=old_th;
curr_th->pid=old_pr;
curr_th->cnxt=old_cnxt;
curr_th->join_th=old_jfront;
curr_th->join_th_rear=old_jrear;
bremoveNode(curr_th->tid);
//printf("MyThreadJoinAll: Blocking swapcontext error... \n");
}
}
int MyThreadJoin(MyThread thread)
{
//printf("MyThreadJoin: START ... \n");
if(thread==NULL)
{
//printf("NULL thread, returning from MyThreadJoin");
return 0;
}
struct node *child_th;
child_th=(struct node *)thread;
//printf("MyThreadJoin: child thread= %d , its parent thread= %d , current invoking thread= %d \n",child_th->tid,child_th->pid,curr_th->tid);
if(curr_th->tid != child_th->pid)
{
//printf("MyThreadJoin: FAILURE : specified thread is not an immediate child of invoking thread...\n");
return -1;
}
//printf("Search of specified child thread in ready queue...\n");
// If the child has already terminated, do not block. Note: A child may have terminated without the parent having joined with it.
int cid=child_th->tid;
int child_exist=0;
// check for child thread into Ready Queue
struct node *tmp=front;
while(tmp!=NULL && tmp->tid != cid )
{
tmp=tmp->next;
}
if(tmp!=NULL && tmp->tid ==cid)
{
child_exist=1;
//printf("Specified child thread exists in Ready queue... \n");
}
//If child not found in Ready Queue, check in Blocked queue
if(child_exist==0)
{
//printf("Specified child thread not in ready queue...search in blocked queue\n");
tmp=bfront;
while(tmp!=NULL && tmp->tid != cid)
{
tmp=tmp->next;
}
if(tmp!=NULL && tmp->tid == cid)
{
child_exist=1;
//printf("Specified child thread exists in Blocked queue... \n");
}
}
if(child_exist==0)
{
//printf("Specified child thread is already terminated. Not blocking the invoking thread...\n");
return 0;
} else if(child_exist == 1)
{
//printf("Specified child thread exists ... \n");
}
//todo: remove this
////printf("MyThreadJoin: RETURN ... \n");
//return 0;
//Child thread exists, need to block the invoking thread and move into Blocked queue
//After blocking, run the first ready thread
//saving join pointers for future failure recovery
struct join_list *old_jfront=curr_th->join_th;
struct join_list *old_jrear=curr_th->join_th_rear;
// Before blocking, need to update join_list of this current thread...
//printf("MyThreadJoin : need to update join_list of this current thread:%d \n",curr_th->tid);
struct join_list *jtmp=(struct join_list *)malloc(sizeof(struct join_list));
if(jtmp==NULL)
{
//printf("No memory allocated... Maximum thread limit reached...returning gracefully...\n");
swapcontext(&dmy_cnxt,&init_cnxt);
}
jtmp->ch_tid=cid;
jtmp->link=NULL;
if((curr_th->join_th)==NULL)
{
curr_th->join_th=jtmp;
curr_th->join_th_rear=curr_th->join_th;
} else
{
curr_th->join_th_rear->link=jtmp;
curr_th->join_th_rear=jtmp;
}
struct node * blocked_th=binsert_q(curr_th->cnxt,curr_th->tid,curr_th->pid,curr_th->join_th,curr_th->join_th_rear);
//printf("MyThreadJoin : current thread:%d entered in BQ , but actual current thread is= %d\n",blocked_th->tid, curr_th->tid);
int old_th=curr_th->tid;
int old_pr=curr_th->pid;
ucontext_t old_cnxt=curr_th->cnxt;
ucontext_t new_cnxt;
struct node * new_th=pop_q();
if(new_th == NULL)
{
//printf(" MyThreadJoin: ready queue empty ... \n");
swapcontext(&dmy_cnxt,&init_cnxt);
}
new_cnxt=new_th->cnxt;
curr_th->tid=new_th->tid;
curr_th->pid=new_th->pid;
curr_th->cnxt=new_th->cnxt;
curr_th->join_th=new_th->join_th;
curr_th->join_th_rear=new_th->join_th_rear;
//printf("MyThreadJoin: swap context from thread : %d to first ready thread : %d ... \n",old_th,curr_th->tid);
if(swapcontext(&(blocked_th->cnxt),&new_cnxt)==-1)
{
curr_th->tid=old_th;
curr_th->pid=old_pr;
curr_th->cnxt=old_cnxt;
curr_th->join_th=old_jfront;
curr_th->join_th_rear=old_jrear;
bremoveNode(curr_th->tid);
//printf("MyThreadJoin: Blocking swapcontext error...");
}
//printf("MyThreadJoin: curr_thread= %d , parent_th = %d ,EXIT... \n",curr_th->tid,curr_th->pid);
}
/* pre: takes in a void* 'n' which must be a pointer to an integer
* post: creates a consumer thread
*/
void* consumer(void *n)
{
int number;
int i;
struct s_product* prod;
struct timeval end_time;
number = *((int*)n);
#ifdef DEBUG
printf("[DEBUG]\tStarting consumer [%d]\n", number);
fflush(stdout);
#endif
/* consume products while we have not reached maxProductCount */
while (gl_env.consumptionCount < gl_env.maxProductCount)
{
#ifdef DEBUG
printf("[DEBUG]\tconsumption count %d\n", gl_env.consumptionCount);
fflush(stdout);
#endif
/* lock and check consumptionCount again in case of weird scheduling */
pthread_mutex_lock(&gl_env.consume_prod_lock);
if (gl_env.consumptionCount == gl_env.maxProductCount)
{
pthread_mutex_unlock(&gl_env.consume_prod_lock);
break;
}
pthread_mutex_unlock(&gl_env.consume_prod_lock);
if (gl_env.scheduling == FCFS)
{
/* do a real pop and keep it til' it's gone */
prod = pop_q();
if (prod == NULL)
break;
gettimeofday(&end_time, NULL);
fprintf(stderr, "Product %d waited %lu\n", prod->id, end_time.tv_usec - prod->time_inserted.tv_usec);
fflush(stderr);
#ifdef DEBUG
printf("[DEBUG]\tConsumer [%d] working on product [%d]\n", number, prod->id);
fflush(stdout);
#endif
for (i = 0; i < prod->life; i++)
fibonacci(10);
/* lock and increment consumptionCount */
pthread_mutex_lock(&gl_env.consume_prod_lock);
gl_env.consumptionCount++;
pthread_mutex_unlock(&gl_env.consume_prod_lock);
printf("Consumer %d has consumed product %d\n", number, prod->id);
fflush(stdout);
gettimeofday(&end_time, NULL);
fprintf(stderr, "Product %d turn-around %lu\n", prod->id, end_time.tv_usec - prod->time_created.tv_usec);
fflush(stderr);
/* free memory */
free(prod);
}
else if (gl_env.scheduling == RR)
{
/* do a "reserved" pop in case we need to put it back */
prod = reserved_pop_q();
if (prod == NULL)
break;
gettimeofday(&end_time, NULL);
fprintf(stderr, "Product %d waited %lu\n", prod->id, end_time.tv_usec - prod->time_inserted.tv_usec);
fflush(stderr);
#ifdef DEBUG
printf("[DEBUG]\tConsumer [%d] working on product [%d]\n", number, prod->id);
fflush(stdout);
#endif
if (prod->life > gl_env.quantum)
{
for (i = 0; i < gl_env.quantum; i++)
fibonacci(10);
/* update the product's life */
prod->life = prod->life - gl_env.quantum;
/* put the product back */
replace_push_q(prod);
}
else
{
for (i = 0; i < prod->life; i++)
fibonacci(10);
/* "fully" remove product */
decrement_q();
/* lock and increment consumptionCount */
pthread_mutex_lock(&gl_env.consume_prod_lock);
++gl_env.consumptionCount;
pthread_mutex_unlock(&gl_env.consume_prod_lock);
printf("Consumer %d has consumed product %d\n", number, prod->id);
fflush(stdout);
gettimeofday(&end_time, NULL);
fprintf(stderr, "Product %d turn-around %lu\n", prod->id, end_time.tv_usec - prod->time_created.tv_usec);
fflush(stderr);
/* free memory */
free(prod);
}
}
/* usleep for 100 milliseconds */
usleep(100000);
}
#ifdef DEBUG
printf("[DEBUG]\tConsumer [%d] exiting\n", number);
fflush(stdout);
#endif
/* return NULL removes compiler warning */
return NULL;
}
