Examples with Channel co.paralleluniverse.strands.channels.Channel used on opensource projects

Example 1 with Channel

use of co.paralleluniverse.strands.channels.Channel in project quasar by puniverse.

the class PipelineTest method testPipeline.

@Test
public void testPipeline() throws Exception {
    final Channel<Integer> i = newChannel();
    final Channel<Integer> o = newChannel();
    final Pipeline<Integer, Integer> p = new Pipeline<>(i, o, new SuspendableAction2<Integer, Channel<Integer>>() {

        @Override
        public void call(final Integer i, final Channel<Integer> out) throws SuspendExecution, InterruptedException {
            out.send(i + 1);
            out.close();
        }
    }, parallelism);
    final Fiber<Long> pf = new Fiber("pipeline", scheduler, p).start();
    final Fiber receiver = new Fiber("receiver", scheduler, new SuspendableRunnable() {

        @Override
        public void run() throws SuspendExecution, InterruptedException {
            final Integer m1 = o.receive();
            final Integer m2 = o.receive();
            final Integer m3 = o.receive();
            final Integer m4 = o.receive();
            assertThat(m1, notNullValue());
            assertThat(m2, notNullValue());
            assertThat(m3, notNullValue());
            assertThat(m4, notNullValue());
            assertThat(ImmutableSet.of(m1, m2, m3, m4), equalTo(ImmutableSet.of(2, 3, 4, 5)));
            try {
                pf.join();
            } catch (ExecutionException ex) {
                // It should never happen
                throw new AssertionError(ex);
            }
            // This is needed, else `isClosed` could return false
            assertNull(o.tryReceive());
            // Can be used reliably only in owner (receiver)
            assertTrue(o.isClosed());
        }
    }).start();
    i.send(1);
    i.send(2);
    i.send(3);
    i.send(4);
    i.close();
    // Join pipeline
    long transferred = pf.get();
    assertThat(transferred, equalTo(p.getTransferred()));
    assertThat(transferred, equalTo(4l));
    receiver.join();
}

Example 2 with Channel

use of co.paralleluniverse.strands.channels.Channel in project quasar by puniverse.

the class Pipeline method parallelTransfer.

private void parallelTransfer() throws SuspendExecution, InterruptedException {
    // 1) Fire workers
    for (int i = 0; i < parallelism; i++) {
        strandFactory.newStrand(SuspendableUtils.runnableToCallable(new SuspendableRunnable() {

            @Override
            public void run() throws SuspendExecution, InterruptedException {
                // Get first job
                Pair<S, Channel<Channel<T>>> job = jobs.receive();
                while (job != null) {
                    // Build result channel
                    final Channel<T> res = resultChannelBuilder.run();
                    // Process
                    transformer.call(job.getFirst(), res);
                    final Channel<Channel<T>> resWrapper = job.getSecond();
                    // Send result asynchronously
                    strandFactory.newStrand(SuspendableUtils.runnableToCallable(new SuspendableRunnable() {

                        @Override
                        public void run() throws SuspendExecution, InterruptedException {
                            resWrapper.send(res);
                        }
                    })).start();
                    // Get next job
                    job = jobs.receive();
                }
                // No more jobs, close results channel and quit worker
                results.close();
            }
        })).start();
    }
    // 2) Send jobs asynchronously
    strandFactory.newStrand(SuspendableUtils.runnableToCallable(new SuspendableRunnable() {

        @Override
        public void run() throws SuspendExecution, InterruptedException {
            // Get first input
            S s = from.receive();
            while (s != null) {
                final Channel<Channel<T>> resultWrapper = Channels.newChannel(1, Channels.OverflowPolicy.BLOCK, true, true);
                jobs.send(new Pair<>(s, resultWrapper));
                results.send(resultWrapper);
                // Get next input
                s = from.receive();
            }
            // No more inputs, close jobs channel and quit
            jobs.close();
        }
    })).start();
    // 3) Collect and transfer results asynchronously
    try {
        final Strand collector = strandFactory.newStrand(SuspendableUtils.runnableToCallable(new SuspendableRunnable() {

            @Override
            public void run() throws SuspendExecution, InterruptedException {
                // Get first result
                Channel<Channel<T>> resWrapper = results.receive();
                while (resWrapper != null) {
                    // Get wrapper
                    Channel<T> res = resWrapper.receive();
                    // Get first actual result
                    T out = res.receive();
                    while (out != null) {
                        // Send to output channel
                        to.send(out);
                        // Increment counter
                        transferred.incrementAndGet();
                        // Get next result
                        out = res.receive();
                    }
                    resWrapper = results.receive();
                }
            // No more results, quit
            }
        })).start();
        // TODO solve nasty instrumentation problems on Strand.join()
        if (collector.isFiber()) {
            Fiber f = (Fiber) collector.getUnderlying();
            f.join();
        } else
            collector.join();
    } catch (ExecutionException ee) {
        throw new AssertionError(ee);
    }
}