12. IPC - Introduction

Inter-Process Communication (IPC) refers to the mechanisms that allow processes to exchange data and synchronize their execution. In Linux, multiple processes often need to communicate—whether they are cooperating on a task, sharing resources, or coordinating work.

Linux provides several IPC mechanisms, each with its own use cases, advantages, and trade-offs.

Types of IPC Mechanisms in Linux

Linux provides multiple IPC techniques, which are generally divided into:

• Communication IPCs: For exchanging data.
• Synchronization IPCs: For coordinating process execution.

Linux provides several IPC mechanisms, which can be broadly categorized as follows:

IPC Mechanism	Kernel Involvement	Communication Type	Synchronization Capability
Pipes (Unnamed Pipes)	Minimal (via file descriptors)	Unidirectional	No
Named Pipes (FIFOs)	Minimal (via filesystem)	Unidirectional (bidirectional with care)	No
Message Queues	Moderate (kernel-managed queue)	Bidirectional	Yes (ordering)
Shared Memory	Moderate (shared address space)	Bidirectional	Needs external synchronization (e.g., semaphores)
Semaphores	High (kernel-managed)	N/A	Yes (synchronization only)
Sockets	High (network stack)	Bidirectional	Yes (explicit)
Signals	Minimal	One-shot notification	Limited (basic notifications)