Single-host concurrency control
It is pretty common to be in situations where there are a number of processes running on a single machine that, at the same time, need to have simultaneous access to a shared resource. Since all of the processes are running within the same operating system, they have access to all the facilities which their operating system provides.
In this section, we show how to use some of these facilities to create a control mechanism that synchronizes the processes. Shared memory plays a key role in most of these control mechanisms; therefore, we heavily rely on what we explained about shared memory in the previous chapter.
The following is a list of POSIX-provided control mechanisms that can be employed while all processes are running on the same POSIX-compliant machine:
- Named POSIX semaphores: The same POSIX semaphores that we explained in Chapter 16, Thread Synchronization, but with one difference: they have a name now and can be used globally...
