Semaphores are any means of communication when flags or lights are employed to communicate . For example , semaphore flags are used to convey messages from one ship to another and traffic lights are a means in which to communicate a signal to traffic . See related link below .
Semaphore was a process of communication using flags to send messages,primarily between sailing vessels. Based on the positioning and patterning of the flags, messages could be sent when other methods were not practical or available. It is easiest to think of semaphore as a form of sign language.
Search Google with: "Linux semaphores" and have a look through the websites on the subject.
As the use of semaphores in the past has caused more problems than created solutions therefore semaphores are not use in the producer and consumer problem.
send signals
Like condoms.
a semaphore is a stoplight and or traffic signal.
The use of semaphores
strong semaphores specify the order in which processes are removed from the queue, which guarantees avoiding starvation. Weak semaphores do not specify the order in which processes are removed from the queue.
the differents is the bathroom time
They were called Semaphores.
Three types of semaphores: 1.General/Counting semaphores: (can take any non-negative value) These are used when you might have multiple devices (like 3 printers or multiple memory buffers). 2.Binary semaphores: (can either be 0 or 1) These are used to gain exclusive access to a single resource (like the serial port, a non-reentrant library routine, or a hard disk drive). A counting semaphore that has a maximum value of 1 is equivalent to a binary semaphore (because the semaphore's value can only be 0 or 1). 3.Mutex semaphores: These are optimized for use in controlling mutually exclusive access to a resource. There are several implementations of this type of semaphore.
There are a number of ways the word semaphores might be used in a sentence. The definition of this word is that it is a system of sending messages using a series of flags in certain positions, signifying different messages with several meanings.
Semaphores are a useful tool for mutual exclusion, but they are not the only such tool provided by the kernel. Instead, most locking is implemented with a mechanism called a spinlock. Unlike semaphores, spinlocks may be used in code that cannot sleep, such as interrupt handlers. When properly used, spinlocks offer higher performance than semaphores in general. They do, however, bring a different set of constraints on their use.