jhalterman

/**
 * A circuit that accepts re-entrant {@link #open()} and {@link #close()} calls and ensures fairness
 * when releasing {@link #await() waiting} threads.
 * 
 * @author Jonathan Halterman
 */
public class ReentrantCircuit {
  private final Sync sync = new Sync();

  /**

jhalterman

/**
 * A waiter where waiting threads can be interrupted (as opposed to awakened).
 * 
 * @author Jonathan Halterman
 */
public class InterruptableWaiter {
  private final Sync sync = new Sync();

  private static final class Sync extends AbstractQueuedSynchronizer {
    private static final long serialVersionUID = 4016766900138538852L;

jhalterman

import io.dropwizard.Configuration;
import io.dropwizard.configuration.ConfigurationFactory;
import io.dropwizard.jackson.Jackson;
import io.dropwizard.jersey.DropwizardResourceConfig;
import io.dropwizard.jersey.jackson.JacksonMessageBodyProvider;
import io.dropwizard.logging.LoggingFactory;
import io.dropwizard.setup.Environment;

import java.io.File;
import java.io.FileNotFoundException;

jhalterman

import io.dropwizard.Application;
import io.dropwizard.Configuration;
import io.dropwizard.cli.ServerCommand;
import io.dropwizard.lifecycle.ServerLifecycleListener;
import io.dropwizard.setup.Bootstrap;
import io.dropwizard.setup.Environment;
import io.dropwizard.testing.junit.ConfigOverride;

import java.util.Enumeration;

jhalterman

  public static <T> T getWithDcl(Supplier<T> supplier, Supplier<T> factory, Object mutex) {
    T object = supplier.get();
    if (object == null) {
      synchronized (mutex) {
        object = supplier.get();
        if (object == null) {
          object = factory.get();
        }
      }
    }

jhalterman

# Usage setjdk 1.8
function setjdk() {  
  if [ $# -ne 0 ]; then  
   removeFromPath '/System/Library/Frameworks/JavaVM.framework/Home/bin'  
   if [ -n "${JAVA_HOME+x}" ]; then  
    removeFromPath $JAVA_HOME  
   fi  
   export JAVA_HOME=`/usr/libexec/java_home -v $@`  
   export PATH=$JAVA_HOME/bin:$PATH  
  fi  

jhalterman

      :cas   (timeout 5000 (assoc op :type :info :value :timed-out)
          (let [cas (reify Function
            (apply [this, tr]
              (let [
                [value value'] (:value op)
                key_var (byte-array (map byte key))
                old_value (.getLong (Tuple/fromBytes (.get (.get tr (byte-array (map byte key))))) 0)
                new_value (.pack (Tuple/from (into-array [value'])))]
              (if (= old_value value)
                (do

jhalterman

(deftest create-cas-test
  (let [test (run!
               (assoc
                 noop-test
                 :name      "foundationdb"
                 :os        ubuntu/os
                 :db        db
                 :client    (cas-register)
                 :model     (model/cas-register)
                 :checker   (checker/compose {:html timeline/html

jhalterman

(defn try-until-success
  "Accepts a try-fn to try a failure-fn to call upon failure, supplying the failure/exception. The try-fn is retried
  until no failure is thrown."
  [try-fn failure-fn]
  (loop []
    (if-let [result (try
                      (try-fn)
                      (catch Exception e
                        (failure-fn e)
                        nil))]

jhalterman

/**
 * An exponentially weighted moving average implementation that decays based on the elapsed time since the last update,
 * approximating a time windowed moving average.
 */
public class MovingAverage {
  private final long windowNanos;

  // Mutable state
  private volatile long lastNanos;
  private volatile double average;