Answer:
The internet is considered as Wide Area Network (WAN).
Answer:
Risk assessment, Input validation and Output validation.
Explanation:
Software development life cycle, SDLC, is a systematic process a software being created must pass through or follow, from the stage of conception to death of the application.
There are various processes that occurs at the beginning of SDLC, a few of the activities are risk management, input and output validation.
Risk management is used to determine the feasibility, usefulness and profitability to cost of the software before development. The input and output validation is for security control access to the data of the software.
Answer:
Worm malware
Explanation:
The worm operates destructively as it replicates itself and keeps spreading within a computer or network. It takes advantage of software and security vulnerabilities.
Once a computer or network is infected, worms replicate themselves, therefore using up the computer and network resources. Among others, one of the major missions of worms is to create a backdoor into a network, to be able to enable the attacker to carry out a more devastating attack.
Since worms take advantage of weak security in the Operating system, it is very important to constantly update the security features of the Operating system. Users must be careful of the emails they open and attachments they download.
Answer:
Explanation:
Following are the Semaphores:
Customers: Counts waiting customers;
Barbers: Number of idle barbers (0 or 1)
mutex: Used for mutual exclusion.
Cutting: Ensures that the barber won’t cut another customer’s hair before the previous customer leaves
Shared data variable:
count_cust: Counts waiting customers. ------------copy of customers. As value of semaphores can’t access directly.
// shared data
semaphore customers = 0; semaphore barbers = 0; semaphore cutting = 0; semaphore mutex = 1;
int count_cust= 0;
void barber() {
while(true) { //shop is always open
wait(customers); //sleep when there are no waiting customers
wait(mutex); //mutex for accessing customers1
count_cust= count_cust-1; //customer left
signal(barbers);
signal(mutex);
cut_hair();
}
}
void customer() {
wait(mutex); //mutex for accessing count_cust
if (count_cust< n) {
count_cust= count_cust+1; //new customer
signal(customers); signal(mutex);
wait(barbers); //wait for available barbers get_haircut();
}
else { //do nothing (leave) when all chairs are used. signal(mutex);
}
}
cut_hair(){ waiting(cutting);
}
get_haircut(){
get hair cut for some time; signal(cutting);
}
