Module-3 Process Synchronization

Cooperating Process

A process that can affect or be affected by other processes executing in the system.

Critical Section Problem

The problem of ensuring that, when one process is executing in its critical section, no other process can be executing in their critical sections.

Mutual Exclusion

If process P_i is executing in its critical section, then no other processes can be executing in their critical sections.

Progress

If no process is executing in its critical section and there are some processes waiting to enter their critical section, those processes cannot be postponed indefinitely.

Bounded Waiting

There exists a limit on the number of times that other processes can enter their critical sections after a request has been made.

Data Inconsistency

A state where concurrent access to shared data results in unexpected values due to overlapping process executions.

Peterson's Solution

A classic algorithmic solution to the critical-section problem, primarily for two processes using flags and a turn variable.

Semaphore

An integer variable used to control access to a common resource in concurrent programming, accessed through wait() and signal() operations.

Binary Semaphore

A type of semaphore that can only take the values 0 or 1, effectively serving as a mutex lock.

Counting Semaphore

A semaphore that can take a range of non-negative values, used to control access to a finite number of instances of a resource.

Deadlock

A situation where two or more processes are waiting indefinitely for an event that can only be caused by one of the waiting processes.

Starvation

A condition where a process is perpetually denied the resources it needs for execution.

Bounded-Buffer Problem

A synchronization issue involving a finite buffer for exchanging messages between producer and consumer processes.

Readers-Writers Problem

A synchronization problem where processes accessing a shared database must manage ensuring readers can read simultaneously while writers require exclusive access.

Dining-Philosophers Problem

A classic synchronization problem illustrating challenges in resource sharing and avoiding deadlock among processes in concurrent execution.