/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.ipc;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
import junit.framework.TestCase;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.BlockingQueue;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.conf.Configuration;
import org.mockito.Matchers;
import static org.apache.hadoop.ipc.FairCallQueue.IPC_CALLQUEUE_PRIORITY_LEVELS_KEY;
public class TestFairCallQueue extends TestCase {
private FairCallQueue<Schedulable> fcq;
private Schedulable mockCall(String id) {
Schedulable mockCall = mock(Schedulable.class);
UserGroupInformation ugi = mock(UserGroupInformation.class);
when(ugi.getUserName()).thenReturn(id);
when(mockCall.getUserGroupInformation()).thenReturn(ugi);
return mockCall;
}
// A scheduler which always schedules into priority zero
private RpcScheduler alwaysZeroScheduler;
{
RpcScheduler sched = mock(RpcScheduler.class);
when(sched.getPriorityLevel(Matchers.<Schedulable>any())).thenReturn(0); // always queue 0
alwaysZeroScheduler = sched;
}
public void setUp() {
Configuration conf = new Configuration();
conf.setInt("ns." + IPC_CALLQUEUE_PRIORITY_LEVELS_KEY, 2);
fcq = new FairCallQueue<Schedulable>(5, "ns", conf);
}
//
// Ensure that FairCallQueue properly implements BlockingQueue
//
public void testPollReturnsNullWhenEmpty() {
assertNull(fcq.poll());
}
public void testPollReturnsTopCallWhenNotEmpty() {
Schedulable call = mockCall("c");
assertTrue(fcq.offer(call));
assertEquals(call, fcq.poll());
// Poll took it out so the fcq is empty
assertEquals(0, fcq.size());
}
public void testOfferSucceeds() {
fcq.setScheduler(alwaysZeroScheduler);
for (int i = 0; i < 5; i++) {
// We can fit 10 calls
assertTrue(fcq.offer(mockCall("c")));
}
assertEquals(5, fcq.size());
}
public void testOfferFailsWhenFull() {
fcq.setScheduler(alwaysZeroScheduler);
for (int i = 0; i < 5; i++) { assertTrue(fcq.offer(mockCall("c"))); }
assertFalse(fcq.offer(mockCall("c"))); // It's full
assertEquals(5, fcq.size());
}
public void testOfferSucceedsWhenScheduledLowPriority() {
// Scheduler will schedule into queue 0 x 5, then queue 1
RpcScheduler sched = mock(RpcScheduler.class);
when(sched.getPriorityLevel(Matchers.<Schedulable>any())).thenReturn(0, 0, 0, 0, 0, 1, 0);
fcq.setScheduler(sched);
for (int i = 0; i < 5; i++) { assertTrue(fcq.offer(mockCall("c"))); }
assertTrue(fcq.offer(mockCall("c")));
assertEquals(6, fcq.size());
}
public void testPeekNullWhenEmpty() {
assertNull(fcq.peek());
}
public void testPeekNonDestructive() {
Schedulable call = mockCall("c");
assertTrue(fcq.offer(call));
assertEquals(call, fcq.peek());
assertEquals(call, fcq.peek()); // Non-destructive
assertEquals(1, fcq.size());
}
public void testPeekPointsAtHead() {
Schedulable call = mockCall("c");
Schedulable next = mockCall("b");
fcq.offer(call);
fcq.offer(next);
assertEquals(call, fcq.peek()); // Peek points at the head
}
public void testPollTimeout() throws InterruptedException {
fcq.setScheduler(alwaysZeroScheduler);
assertNull(fcq.poll(10, TimeUnit.MILLISECONDS));
}
public void testPollSuccess() throws InterruptedException {
fcq.setScheduler(alwaysZeroScheduler);
Schedulable call = mockCall("c");
assertTrue(fcq.offer(call));
assertEquals(call, fcq.poll(10, TimeUnit.MILLISECONDS));
assertEquals(0, fcq.size());
}
public void testOfferTimeout() throws InterruptedException {
fcq.setScheduler(alwaysZeroScheduler);
for (int i = 0; i < 5; i++) {
assertTrue(fcq.offer(mockCall("c"), 10, TimeUnit.MILLISECONDS));
}
assertFalse(fcq.offer(mockCall("e"), 10, TimeUnit.MILLISECONDS)); // It's full
assertEquals(5, fcq.size());
}
public void testDrainTo() {
Configuration conf = new Configuration();
conf.setInt("ns." + IPC_CALLQUEUE_PRIORITY_LEVELS_KEY, 2);
FairCallQueue<Schedulable> fcq2 = new FairCallQueue<Schedulable>(10, "ns", conf);
fcq.setScheduler(alwaysZeroScheduler);
fcq2.setScheduler(alwaysZeroScheduler);
// Start with 3 in fcq, to be drained
for (int i = 0; i < 3; i++) {
fcq.offer(mockCall("c"));
}
fcq.drainTo(fcq2);
assertEquals(0, fcq.size());
assertEquals(3, fcq2.size());
}
public void testDrainToWithLimit() {
Configuration conf = new Configuration();
conf.setInt("ns." + IPC_CALLQUEUE_PRIORITY_LEVELS_KEY, 2);
FairCallQueue<Schedulable> fcq2 = new FairCallQueue<Schedulable>(10, "ns", conf);
fcq.setScheduler(alwaysZeroScheduler);
fcq2.setScheduler(alwaysZeroScheduler);
// Start with 3 in fcq, to be drained
for (int i = 0; i < 3; i++) {
fcq.offer(mockCall("c"));
}
fcq.drainTo(fcq2, 2);
assertEquals(1, fcq.size());
assertEquals(2, fcq2.size());
}
public void testInitialRemainingCapacity() {
assertEquals(10, fcq.remainingCapacity());
}
public void testFirstQueueFullRemainingCapacity() {
fcq.setScheduler(alwaysZeroScheduler);
while (fcq.offer(mockCall("c"))) ; // Queue 0 will fill up first, then queue 1
assertEquals(5, fcq.remainingCapacity());
}
public void testAllQueuesFullRemainingCapacity() {
RpcScheduler sched = mock(RpcScheduler.class);
when(sched.getPriorityLevel(Matchers.<Schedulable>any())).thenReturn(0, 0, 0, 0, 0, 1, 1, 1, 1, 1);
fcq.setScheduler(sched);
while (fcq.offer(mockCall("c"))) ;
assertEquals(0, fcq.remainingCapacity());
assertEquals(10, fcq.size());
}
public void testQueuesPartialFilledRemainingCapacity() {
RpcScheduler sched = mock(RpcScheduler.class);
when(sched.getPriorityLevel(Matchers.<Schedulable>any())).thenReturn(0, 1, 0, 1, 0);
fcq.setScheduler(sched);
for (int i = 0; i < 5; i++) { fcq.offer(mockCall("c")); }
assertEquals(5, fcq.remainingCapacity());
assertEquals(5, fcq.size());
}
/**
* Putter produces FakeCalls
*/
public class Putter implements Runnable {
private final BlockingQueue<Schedulable> cq;
public final String tag;
public volatile int callsAdded = 0; // How many calls we added, accurate unless interrupted
private final int maxCalls;
private final CountDownLatch latch;
public Putter(BlockingQueue<Schedulable> aCq, int maxCalls, String tag,
CountDownLatch latch) {
this.maxCalls = maxCalls;
this.cq = aCq;
this.tag = tag;
this.latch = latch;
}
private String getTag() {
if (this.tag != null) return this.tag;
return "";
}
@Override
public void run() {
try {
// Fill up to max (which is infinite if maxCalls < 0)
while (callsAdded < maxCalls || maxCalls < 0) {
cq.put(mockCall(getTag()));
callsAdded++;
latch.countDown();
}
} catch (InterruptedException e) {
return;
}
}
}
/**
* Taker consumes FakeCalls
*/
public class Taker implements Runnable {
private final BlockingQueue<Schedulable> cq;
public final String tag; // if >= 0 means we will only take the matching tag, and put back
// anything else
public volatile int callsTaken = 0; // total calls taken, accurate if we aren't interrupted
public volatile Schedulable lastResult = null; // the last thing we took
private final int maxCalls; // maximum calls to take
private final CountDownLatch latch;
private IdentityProvider uip;
public Taker(BlockingQueue<Schedulable> aCq, int maxCalls, String tag,
CountDownLatch latch) {
this.maxCalls = maxCalls;
this.cq = aCq;
this.tag = tag;
this.uip = new UserIdentityProvider();
this.latch = latch;
}
@Override
public void run() {
try {
// Take while we don't exceed maxCalls, or if maxCalls is undefined (< 0)
while (callsTaken < maxCalls || maxCalls < 0) {
Schedulable res = cq.take();
String identity = uip.makeIdentity(res);
if (tag != null && this.tag.equals(identity)) {
// This call does not match our tag, we should put it back and try again
cq.put(res);
} else {
callsTaken++;
latch.countDown();
lastResult = res;
}
}
} catch (InterruptedException e) {
return;
}
}
}
// Assert we can take exactly the numberOfTakes
public void assertCanTake(BlockingQueue<Schedulable> cq, int numberOfTakes,
int takeAttempts) throws InterruptedException {
CountDownLatch latch = new CountDownLatch(numberOfTakes);
Taker taker = new Taker(cq, takeAttempts, "default", latch);
Thread t = new Thread(taker);
t.start();
latch.await();
assertEquals(numberOfTakes, taker.callsTaken);
t.interrupt();
}
// Assert we can put exactly the numberOfPuts
public void assertCanPut(BlockingQueue<Schedulable> cq, int numberOfPuts,
int putAttempts) throws InterruptedException {
CountDownLatch latch = new CountDownLatch(numberOfPuts);
Putter putter = new Putter(cq, putAttempts, null, latch);
Thread t = new Thread(putter);
t.start();
latch.await();
assertEquals(numberOfPuts, putter.callsAdded);
t.interrupt();
}
// Make sure put will overflow into lower queues when the top is full
public void testPutOverflows() throws InterruptedException {
fcq.setScheduler(alwaysZeroScheduler);
// We can fit more than 5, even though the scheduler suggests the top queue
assertCanPut(fcq, 8, 8);
assertEquals(8, fcq.size());
}
public void testPutBlocksWhenAllFull() throws InterruptedException {
fcq.setScheduler(alwaysZeroScheduler);
assertCanPut(fcq, 10, 10); // Fill up
assertEquals(10, fcq.size());
// Put more which causes overflow
assertCanPut(fcq, 0, 1); // Will block
}
public void testTakeBlocksWhenEmpty() throws InterruptedException {
fcq.setScheduler(alwaysZeroScheduler);
assertCanTake(fcq, 0, 1);
}
public void testTakeRemovesCall() throws InterruptedException {
fcq.setScheduler(alwaysZeroScheduler);
Schedulable call = mockCall("c");
fcq.offer(call);
assertEquals(call, fcq.take());
assertEquals(0, fcq.size());
}
public void testTakeTriesNextQueue() throws InterruptedException {
// Make a FCQ filled with calls in q 1 but empty in q 0
RpcScheduler q1Scheduler = mock(RpcScheduler.class);
when(q1Scheduler.getPriorityLevel(Matchers.<Schedulable>any())).thenReturn(1);
fcq.setScheduler(q1Scheduler);
// A mux which only draws from q 0
RpcMultiplexer q0mux = mock(RpcMultiplexer.class);
when(q0mux.getAndAdvanceCurrentIndex()).thenReturn(0);
fcq.setMultiplexer(q0mux);
Schedulable call = mockCall("c");
fcq.put(call);
// Take from q1 even though mux said q0, since q0 empty
assertEquals(call, fcq.take());
assertEquals(0, fcq.size());
}
}