What is a spinlock? What is an alternative to using spinlocks?

A file is to be shared among different processes, each of which has a unique id number and a priority level number. The file can be accessed simultaneously by several processes, subject to the following constraint: The process priority number must be less than or equal to the priority numbers all of the other processes that are currently accessing the file.

Using pseudocode (see below), write a monitor to coordinate access to the file.

Monitor name

{

//shared variables

REQUESTprocedure ( )

{

}

RELEASEprocedure ( )

{

}

. . .

//initializtion code( )

{

}

}