Explain the concept of shared memory and its use in inter-process communication.

Shared memory is an inter-process communication (IPC) mechanism where multiple processes can jointly use the same memory segment to exchange data.

Advantages:

• High data exchange speed, as data is not copied between processes.
• Efficiency in transmitting large volumes of information.

Usage:

• Processes create or attach to a shared memory segment.
• Locking mechanisms (mutexes, semaphores) are usually used to synchronize access and prevent data races.

Example: two processes can exchange messages through a pre-allocated shared memory segment, writing and reading data according to agreed rules.

In Unix systems, system calls shmget, shmat, shmdt, shmctl are used for working with shared memory.