java - Multi producer single consumer queue without dedicated consumer thread -

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i'm writing async application submits elements work queue processing. requirements are:

  • there no background thread listening on queue. thread submits element queue may responsible consuming queue.
  • there can multiple concurrent producers, 1 thread can active consumer.
  • if thread submits element thread b actively consuming queue, thread should return immediately. no waiting allowed.

here example of i'm trying do:

final queue<t> queue = new concurrentlinkedqueue<>(); final atomicboolean processing = new atomicboolean();  void offer(t t) {     queue.offer(t);      (;;) {         if (processing.compareandset(false, true)) {             try {                 (;;) {                     t t = queue.poll();                     if (t == null) {                         break;                     }                     // process t                 }             } {                 processing.set(false);             }              // see if thread submitted element didn't process             // if not, can break             if (queue.isempty()) {                 break;             }         } else {             // losers should exit             break;         }     } }

i think code works, problem sounds standard know if there textbook solution or @ least common name. far find algorithms require worker thread listening on queue.

your code correct, problem not seen standard: usually, having background thread not expensive, as:

  1. having no finite time garantee producers. possible producer work long time in consumer mode.

  2. complicate producer's code.

in case, question's title (mpsc without dedicated consumer thread) describes problem well. resolve can combine trylock/unlock approach mpsc implementation without notification mechanism. additional requirement mpsc concurrent queue.isempty() method, not problem.


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