Answer:
int sumid=0; /* Shared var that contains the sum of the process ids currently accessing the file */
int waiting=0; /* Number of process waiting on the semaphore OkToAccess */
semaphore mutex=1; /* Our good old Semaphore variable ;) */
semaphore OKToAccess=0; /* The synchronization semaphore */
get_access(int id)
{
sem_wait(mutex);
while(sumid+id > n) {
waiting++;
sem_signal(mutex);
sem_wait(OKToAccess);
sem_wait(mutex);
}
sumid += id;
sem_signal(mutex);
}
release_access(int id)
{
int i;
sem_wait(mutex);
sumid -= id;
for (i=0; i < waiting;++i) {
sem_signal(OKToAccess);
}
waiting = 0;
sem_signal(mutex);
}
main()
{
get_access(id);
do_stuff();
release_access(id);
}
Some points to note about the solution:
release_access wakes up all waiting processes. It is NOT ok to wake up the first waiting process in this problem --- that process may have too large a value of id. Also, more than one process may be eligible to go in (if those processes have small ids) when one process releases access.
woken up processes try to see if they can get in. If not, they go back to sleep.
waiting is set to 0 in release_access after the for loop. That avoids unnecessary signals from subsequent release_accesses. Those signals would not make the solution wrong, just less efficient as processes will be woken up unnecessarily.
Answer:
Charge back.
Explanation:
A chargeback is a charge that is returned to a payment card after a customer successfully disputes an item on their account transactions report. Simply put, it is the reversal of a credit card payment that comes directly from the bank.
Most commonly the payer is a consumer.
A chargeback may occur on bank accounts or credit cards. They can be granted to a cardholder for a variety of reasons. A chargeback can be considered a refund since it returns specified funds taken from an account through a prior purchase. Chargebacks are focused on charges that have been fully processed and settled. Chargebacks can often take several days for full settlement as they must be reversed through an electronic process involving multiple entities.
The chargeback is ordered by the bank that issued the consumer's payment card.
Answer:
lol u can barly call this a code
Explanation:
its just a type error code i think
Answer: 4) Hierarchy
Explanation:
The main components of the relational database are table, entity and attributes. As, relational data base is the method of arranging and maintaining the data and each table in the database contain data in the entity and the attributes. Hierarchy is not the component of the database as it is included in the type oh hierarchical database not in relational database.
Answer:
Yes correct. Absolutely breathtaking. You should create poetry with your writing skills.
