Producer Consumer Pattern
The producer consumer pattern separates threads that create work from threads that process it, connected by a shared bounded buffer or queue.
- Producers generate items and place them in the queue.
- Consumers remove items and process them.
- The queue acts as a buffer that absorbs bursts and smooths differing speeds.
The pattern shines when producers and consumers run at uneven rates. A fast producer does not have to wait for a slow consumer, up to the buffer limit.
Correct coordination is essential. When the buffer is full, producers must block or wait. When it is empty, consumers must wait. This is usually built with a mutex plus condition variables, or with a thread safe blocking queue that handles the waiting internally.
A bounded buffer provides natural backpressure: if consumers fall behind, the full queue slows producers, preventing unbounded memory growth.
Key idea
Producer consumer decouples generation from processing through a bounded queue that buffers bursts and provides backpressure.