intertask

Intertask refers to the set of techniques and mechanisms that enable communication and synchronization between tasks within a multitasking system. It is commonly used in real-time operating systems and embedded software to coordinate work among concurrent tasks, which may run under a single process or across processes depending on the operating system’s architecture.

Intertask communication (ITC) methods include message passing with queues or mailboxes, shared memory coordinated by synchronization primitives such as mutexes or semaphores, and signaling mechanisms like events or signals. Other approaches include pipes and event flags. Intertask coordination also encompasses synchronization of execution order, data integrity, and timing constraints, which are critical in real-time and tightly coupled systems.

In practice, intertask design addresses patterns such as producer-consumer, request-reply, and publish-subscribe. Real-time operating systems often provide built-in primitives for intertask communication with varying guarantees about latency, determinism, and priority handling. For example, message queues allow a sender to place a data item for a receiver, while semaphores control access to shared resources. Event flags or signals enable one task to notify others of state changes. The choice of mechanism depends on factors such as data size, timing requirements, memory constraints, and whether tasks share memory.

Intertask concepts differ from interprocess communication primarily in scope and isolation. In single-address-space systems, intertask communication may resemble thread-level synchronization; in multi-process architectures, ITC can involve separate IPC facilities. Modern software design often combines multiple intertask mechanisms to support modular, responsive systems such as producer-consumer pipelines and event-driven controllers.