A thread pool provides reusable worker threads for executing multiple tasks without creating a new thread for each task. In Clojure concurrency, agents and futures share a pool, while workload-specific dispatch can use a separate executor. section 14.6
Use thread-pool controls to match execution behavior to the workload:
- Send ordinary agent actions with send; use send-off when an action may keep a thread busy for a long time. section 14.6
- Route an action through a chosen executor with send-via, or replace the agent send executors globally with set-agent-send-executor! and set-agent-send-off-executor!. section 14.6
(import '[java.util.concurrent Executors]) (def fj-pool (Executors/newWorkStealingPool)) ; #1 (defn send-fj [^clojure.lang.Agent a f & args] (apply send-via fj-pool a f args)) ; #2 (def a (agent 1)) ; #3 (send-fj a inc) (await a) @a
A custom work-stealing pool can dispatch an agent action through send-via while preserving the agent’s ordered state updates. section 14.6
(import '[java.util.concurrent Executors]) (def fj-pool (Executors/newWorkStealingPool 100)) ; #1 (set-agent-send-executor! fj-pool) ; #2 (set-agent-send-off-executor! fj-pool)
The same executor can be installed for both regular agent sends and send-off actions. section 14.6
