Threads

OS threads for CPU-bound work. For I/O-bound concurrency, prefer ev/spawn / ev/join (see concurrency.md).

spawn and join

(def handle (sys/spawn (fn [] (+ 1 2))))
(sys/join handle)          # => 3
(sys/thread-id)            # current OS thread ID

sys/spawn deep-copies the closure and all captured values into the new thread via SendValue. The threads share nothing — mutations on one side are invisible to the other. Values that cannot be serialized (fibers, open ports) will error at spawn time.

Channels

Crossbeam-based channels for inter-fiber and inter-thread messaging.

(def [tx rx] (chan))           # unbounded channel

(chan/send tx 42)              # => [:ok]
(chan/recv rx)                 # => [:ok 42]

(chan/clone tx)                # clone sender (multiple producers)
(chan/close tx)                # close sender half
(chan/close-recv rx)           # close receiver half

See also

• concurrency.md — async concurrency with ev/spawn
• fibers — fiber architecture