Permit doAcquire()

in uforwarder/src/main/java/com/uber/data/kafka/consumerproxy/worker/limiter/LongFixedInflightLimiter.java [94:127]

• 29 lines of code
• 10 McCabe index (conditional complexity)

  Permit doAcquire(AcquireMode acquireMode, int n) throws InterruptedException {
    if (n < 0) {
      return NoopPermit.INSTANCE;
    }

    if (!isClosed.get() && limit != 0) {
      synchronized (lock) {
        queueLength.addAndGet(n);
        try {
          while (!isClosed.get() && limit != 0) {
            long nInflight = inflight.get();
            if (nInflight >= 0
                && // note, nInflight could overflow
                nInflight <= limit - n) {
              inflight.addAndGet(n);
              return new FixedPermit(n);
            } else if (acquireMode == AcquireMode.DryRun) {
              return NoopPermit.INSTANCE;
            } else if (acquireMode == AcquireMode.NonBlocking) {
              // unblock caller if failed to get permit
              return null;
            }
            // if not get permitted, wait for the unlock signal and try acquire permit again.
            lock.wait();
          }
        } finally {
          queueLength.addAndGet(-n);
        }
      }
    }

    // Always permit if limiter is closed
    return NoopPermit.INSTANCE;
  }