POSIX Interprocess Communication

POSIX interprocess communication (IPC) is a variation of System V interprocess communication. Like System V objects, POSIX IPC objects have read and write, but not execute, permissions for the owner, the owner's group, and for others. There is no way for the owner of a POSIX IPC object to assign a different owner. POSIX IPC includes the following features:

• Messages allow processes to send formatted data streams to arbitrary processes.

• Semaphores allow processes to synchronize execution.

• Shared memory allows processes to share parts of their virtual address space.

Unlike the System V IPC interfaces, the POSIX IPC interfaces are all multithread safe.