org.apache.hadoop.hbase.master.procedure.MasterProcedureScheduler Maven / Gradle / Ivy
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/**
* 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,
* WITHOUTKey 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.hbase.master.procedure;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.TableExistsException;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.TableNotFoundException;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import org.apache.hadoop.hbase.master.TableLockManager;
import org.apache.hadoop.hbase.master.TableLockManager.TableLock;
import org.apache.hadoop.hbase.master.procedure.TableProcedureInterface.TableOperationType;
import org.apache.hadoop.hbase.procedure2.Procedure;
import org.apache.hadoop.hbase.procedure2.ProcedureRunnableSet;
/**
* ProcedureRunnableSet for the Master Procedures.
* This RunnableSet tries to provide to the ProcedureExecutor procedures
* that can be executed without having to wait on a lock.
* Most of the master operations can be executed concurrently, if they
* are operating on different tables (e.g. two create table can be performed
* at the same, time assuming table A and table B) or against two different servers; say
* two servers that crashed at about the same time.
*
* Each procedure should implement an interface providing information for this queue.
* for example table related procedures should implement TableProcedureInterface.
* each procedure will be pushed in its own queue, and based on the operation type
* we may take smarter decision. e.g. we can abort all the operations preceding
* a delete table, or similar.
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class MasterProcedureScheduler implements ProcedureRunnableSet {
private static final Log LOG = LogFactory.getLog(MasterProcedureScheduler.class);
private final TableLockManager lockManager;
private final ReentrantLock schedLock = new ReentrantLock();
private final Condition schedWaitCond = schedLock.newCondition();
private final FairQueue serverRunQueue = new FairQueue();
private final FairQueue tableRunQueue = new FairQueue();
private int queueSize = 0;
private final Object[] serverBuckets = new Object[128];
private Queue namespaceMap = null;
private Queue tableMap = null;
private final int metaTablePriority;
private final int userTablePriority;
private final int sysTablePriority;
// TODO: metrics
private long pollCalls = 0;
private long nullPollCalls = 0;
public MasterProcedureScheduler(final Configuration conf, final TableLockManager lockManager) {
this.lockManager = lockManager;
// TODO: should this be part of the HTD?
metaTablePriority = conf.getInt("hbase.master.procedure.queue.meta.table.priority", 3);
sysTablePriority = conf.getInt("hbase.master.procedure.queue.system.table.priority", 2);
userTablePriority = conf.getInt("hbase.master.procedure.queue.user.table.priority", 1);
}
@Override
public void addFront(Procedure proc) {
doAdd(proc, true);
}
@Override
public void addBack(Procedure proc) {
doAdd(proc, false);
}
@Override
public void yield(final Procedure proc) {
doAdd(proc, isTableProcedure(proc));
}
private void doAdd(final Procedure proc, final boolean addFront) {
schedLock.lock();
try {
if (isTableProcedure(proc)) {
doAdd(tableRunQueue, getTableQueue(getTableName(proc)), proc, addFront);
} else if (isServerProcedure(proc)) {
doAdd(serverRunQueue, getServerQueue(getServerName(proc)), proc, addFront);
} else {
// TODO: at the moment we only have Table and Server procedures
// if you are implementing a non-table/non-server procedure, you have two options: create
// a group for all the non-table/non-server procedures or try to find a key for your
// non-table/non-server procedures and implement something similar to the TableRunQueue.
throw new UnsupportedOperationException(
"RQs for non-table/non-server procedures are not implemented yet");
}
schedWaitCond.signal();
} finally {
schedLock.unlock();
}
}
private > void doAdd(final FairQueue fairq,
final Queue queue, final Procedure proc, final boolean addFront) {
queue.add(proc, addFront);
if (!(queue.isSuspended() || queue.hasExclusiveLock())) {
if (queue.size() == 1 && !IterableList.isLinked(queue)) {
fairq.add(queue);
}
queueSize++;
}
}
@Override
public Procedure poll() {
return poll(-1);
}
@edu.umd.cs.findbugs.annotations.SuppressWarnings("WA_AWAIT_NOT_IN_LOOP")
Procedure poll(long waitNsec) {
Procedure pollResult = null;
schedLock.lock();
try {
if (queueSize == 0) {
if (waitNsec < 0) {
schedWaitCond.await();
} else {
schedWaitCond.awaitNanos(waitNsec);
}
if (queueSize == 0) {
return null;
}
}
// For now, let server handling have precedence over table handling; presumption is that it
// is more important handling crashed servers than it is running the
// enabling/disabling tables, etc.
pollResult = doPoll(serverRunQueue);
if (pollResult == null) {
pollResult = doPoll(tableRunQueue);
}
// update metrics
pollCalls++;
nullPollCalls += (pollResult == null) ? 1 : 0;
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
} finally {
schedLock.unlock();
}
return pollResult;
}
private > Procedure doPoll(final FairQueue fairq) {
Queue rq = fairq.poll();
if (rq == null || !rq.isAvailable()) {
return null;
}
assert !rq.isSuspended() : "rq=" + rq + " is suspended";
Procedure pollResult = rq.poll();
this.queueSize--;
if (rq.isEmpty() || rq.requireExclusiveLock(pollResult)) {
removeFromRunQueue(fairq, rq);
}
return pollResult;
}
@Override
public void clear() {
// NOTE: USED ONLY FOR TESTING
schedLock.lock();
try {
// Remove Servers
for (int i = 0; i < serverBuckets.length; ++i) {
clear((ServerQueue)serverBuckets[i], serverRunQueue);
serverBuckets[i] = null;
}
// Remove Tables
clear(tableMap, tableRunQueue);
tableMap = null;
assert queueSize == 0 : "expected queue size to be 0, got " + queueSize;
} finally {
schedLock.unlock();
}
}
private > void clear(Queue treeMap, FairQueue fairq) {
while (treeMap != null) {
Queue node = AvlTree.getFirst(treeMap);
assert !node.isSuspended() : "can't clear suspended " + node.getKey();
treeMap = AvlTree.remove(treeMap, node.getKey());
removeFromRunQueue(fairq, node);
}
}
@Override
public void signalAll() {
schedLock.lock();
try {
schedWaitCond.signalAll();
} finally {
schedLock.unlock();
}
}
@Override
public int size() {
schedLock.lock();
try {
return queueSize;
} finally {
schedLock.unlock();
}
}
@Override
public void completionCleanup(Procedure proc) {
if (proc instanceof TableProcedureInterface) {
TableProcedureInterface iProcTable = (TableProcedureInterface)proc;
boolean tableDeleted;
if (proc.hasException()) {
IOException procEx = proc.getException().unwrapRemoteException();
if (iProcTable.getTableOperationType() == TableOperationType.CREATE) {
// create failed because the table already exist
tableDeleted = !(procEx instanceof TableExistsException);
} else {
// the operation failed because the table does not exist
tableDeleted = (procEx instanceof TableNotFoundException);
}
} else {
// the table was deleted
tableDeleted = (iProcTable.getTableOperationType() == TableOperationType.DELETE);
}
if (tableDeleted) {
markTableAsDeleted(iProcTable.getTableName());
return;
}
} else {
// No cleanup for ServerProcedureInterface types, yet.
return;
}
}
private > void addToRunQueue(FairQueue fairq, Queue queue) {
if (IterableList.isLinked(queue)) return;
if (!queue.isEmpty()) {
fairq.add(queue);
queueSize += queue.size();
}
}
private > void removeFromRunQueue(FairQueue fairq, Queue queue) {
if (!IterableList.isLinked(queue)) return;
fairq.remove(queue);
queueSize -= queue.size();
}
// ============================================================================
// TODO: Metrics
// ============================================================================
public long getPollCalls() {
return pollCalls;
}
public long getNullPollCalls() {
return nullPollCalls;
}
// ============================================================================
// Event Helpers
// ============================================================================
public boolean waitEvent(ProcedureEvent event, Procedure procedure) {
return waitEvent(event, procedure, false);
}
public boolean waitEvent(ProcedureEvent event, Procedure procedure, boolean suspendQueue) {
synchronized (event) {
if (event.isReady()) {
return false;
}
// TODO: Suspend single procedure not implemented yet, fallback to suspending the queue
if (!suspendQueue) suspendQueue = true;
if (isTableProcedure(procedure)) {
waitTableEvent(event, procedure, suspendQueue);
} else if (isServerProcedure(procedure)) {
waitServerEvent(event, procedure, suspendQueue);
} else {
// TODO: at the moment we only have Table and Server procedures
// if you are implementing a non-table/non-server procedure, you have two options: create
// a group for all the non-table/non-server procedures or try to find a key for your
// non-table/non-server procedures and implement something similar to the TableRunQueue.
throw new UnsupportedOperationException(
"RQs for non-table/non-server procedures are not implemented yet");
}
}
return true;
}
private void waitTableEvent(ProcedureEvent event, Procedure procedure, boolean suspendQueue) {
final TableName tableName = getTableName(procedure);
final boolean isDebugEnabled = LOG.isDebugEnabled();
schedLock.lock();
try {
TableQueue queue = getTableQueue(tableName);
if (queue.isSuspended()) return;
// TODO: if !suspendQueue
if (isDebugEnabled) {
LOG.debug("Suspend table queue " + tableName);
}
queue.setSuspended(true);
removeFromRunQueue(tableRunQueue, queue);
event.suspendTableQueue(queue);
} finally {
schedLock.unlock();
}
}
private void waitServerEvent(ProcedureEvent event, Procedure procedure, boolean suspendQueue) {
final ServerName serverName = getServerName(procedure);
final boolean isDebugEnabled = LOG.isDebugEnabled();
schedLock.lock();
try {
// TODO: This will change once we have the new AM
ServerQueue queue = getServerQueue(serverName);
if (queue.isSuspended()) return;
// TODO: if !suspendQueue
if (isDebugEnabled) {
LOG.debug("Suspend server queue " + serverName);
}
queue.setSuspended(true);
removeFromRunQueue(serverRunQueue, queue);
event.suspendServerQueue(queue);
} finally {
schedLock.unlock();
}
}
public void suspend(ProcedureEvent event) {
final boolean isDebugEnabled = LOG.isDebugEnabled();
synchronized (event) {
event.setReady(false);
if (isDebugEnabled) {
LOG.debug("Suspend event " + event);
}
}
}
public void wake(ProcedureEvent event) {
final boolean isDebugEnabled = LOG.isDebugEnabled();
synchronized (event) {
event.setReady(true);
if (isDebugEnabled) {
LOG.debug("Wake event " + event);
}
schedLock.lock();
try {
while (event.hasWaitingTables()) {
Queue queue = event.popWaitingTable();
addToRunQueue(tableRunQueue, queue);
}
// TODO: This will change once we have the new AM
while (event.hasWaitingServers()) {
Queue queue = event.popWaitingServer();
addToRunQueue(serverRunQueue, queue);
}
if (queueSize > 1) {
schedWaitCond.signalAll();
} else if (queueSize > 0) {
schedWaitCond.signal();
}
} finally {
schedLock.unlock();
}
}
}
public static class ProcedureEvent {
private final String description;
private Queue waitingServers = null;
private Queue waitingTables = null;
private boolean ready = false;
public ProcedureEvent(String description) {
this.description = description;
}
public synchronized boolean isReady() {
return ready;
}
private synchronized void setReady(boolean isReady) {
this.ready = isReady;
}
private void suspendTableQueue(Queue queue) {
waitingTables = IterableList.append(waitingTables, queue);
}
private void suspendServerQueue(Queue queue) {
waitingServers = IterableList.append(waitingServers, queue);
}
private boolean hasWaitingTables() {
return waitingTables != null;
}
private Queue popWaitingTable() {
Queue node = waitingTables;
waitingTables = IterableList.remove(waitingTables, node);
node.setSuspended(false);
return node;
}
private boolean hasWaitingServers() {
return waitingServers != null;
}
private Queue popWaitingServer() {
Queue node = waitingServers;
waitingServers = IterableList.remove(waitingServers, node);
node.setSuspended(false);
return node;
}
@Override
public String toString() {
return String.format("ProcedureEvent(%s)", description);
}
}
// ============================================================================
// Table Queue Lookup Helpers
// ============================================================================
private TableQueue getTableQueueWithLock(TableName tableName) {
schedLock.lock();
try {
return getTableQueue(tableName);
} finally {
schedLock.unlock();
}
}
private TableQueue getTableQueue(TableName tableName) {
Queue node = AvlTree.get(tableMap, tableName);
if (node != null) return (TableQueue)node;
NamespaceQueue nsQueue = getNamespaceQueue(tableName.getNamespaceAsString());
node = new TableQueue(tableName, nsQueue, getTablePriority(tableName));
tableMap = AvlTree.insert(tableMap, node);
return (TableQueue)node;
}
private void removeTableQueue(TableName tableName) {
tableMap = AvlTree.remove(tableMap, tableName);
}
private int getTablePriority(TableName tableName) {
if (tableName.equals(TableName.META_TABLE_NAME)) {
return metaTablePriority;
} else if (tableName.isSystemTable()) {
return sysTablePriority;
}
return userTablePriority;
}
private static boolean isTableProcedure(Procedure proc) {
return proc instanceof TableProcedureInterface;
}
private static TableName getTableName(Procedure proc) {
return ((TableProcedureInterface)proc).getTableName();
}
// ============================================================================
// Namespace Queue Lookup Helpers
// ============================================================================
private NamespaceQueue getNamespaceQueue(String namespace) {
Queue node = AvlTree.get(namespaceMap, namespace);
if (node != null) return (NamespaceQueue)node;
node = new NamespaceQueue(namespace);
namespaceMap = AvlTree.insert(namespaceMap, node);
return (NamespaceQueue)node;
}
// ============================================================================
// Server Queue Lookup Helpers
// ============================================================================
private ServerQueue getServerQueueWithLock(ServerName serverName) {
schedLock.lock();
try {
return getServerQueue(serverName);
} finally {
schedLock.unlock();
}
}
private ServerQueue getServerQueue(ServerName serverName) {
int index = getBucketIndex(serverBuckets, serverName.hashCode());
Queue root = getTreeRoot(serverBuckets, index);
Queue node = AvlTree.get(root, serverName);
if (node != null) return (ServerQueue)node;
node = new ServerQueue(serverName);
serverBuckets[index] = AvlTree.insert(root, node);
return (ServerQueue)node;
}
private void removeServerQueue(ServerName serverName) {
int index = getBucketIndex(serverBuckets, serverName.hashCode());
serverBuckets[index] = AvlTree.remove((ServerQueue)serverBuckets[index], serverName);
}
@SuppressWarnings("unchecked")
private static > Queue getTreeRoot(Object[] buckets, int index) {
return (Queue) buckets[index];
}
private static int getBucketIndex(Object[] buckets, int hashCode) {
return Math.abs(hashCode) % buckets.length;
}
private static boolean isServerProcedure(Procedure proc) {
return proc instanceof ServerProcedureInterface;
}
private static ServerName getServerName(Procedure proc) {
return ((ServerProcedureInterface)proc).getServerName();
}
// ============================================================================
// Table and Server Queue Implementation
// ============================================================================
public static class ServerQueue extends QueueImpl {
public ServerQueue(ServerName serverName) {
super(serverName);
}
public boolean requireExclusiveLock(Procedure proc) {
ServerProcedureInterface spi = (ServerProcedureInterface)proc;
switch (spi.getServerOperationType()) {
case CRASH_HANDLER:
return true;
default:
break;
}
throw new UnsupportedOperationException("unexpected type " + spi.getServerOperationType());
}
}
public static class TableQueue extends QueueImpl {
private final NamespaceQueue namespaceQueue;
private TableLock tableLock = null;
public TableQueue(TableName tableName, NamespaceQueue namespaceQueue, int priority) {
super(tableName, priority);
this.namespaceQueue = namespaceQueue;
}
public NamespaceQueue getNamespaceQueue() {
return namespaceQueue;
}
@Override
public synchronized boolean isAvailable() {
return super.isAvailable() && !namespaceQueue.hasExclusiveLock();
}
// TODO: We can abort pending/in-progress operation if the new call is
// something like drop table. We can Override addBack(),
// check the type and abort all the in-flight procedurs.
private boolean canAbortPendingOperations(Procedure proc) {
TableProcedureInterface tpi = (TableProcedureInterface)proc;
switch (tpi.getTableOperationType()) {
case DELETE:
return true;
default:
return false;
}
}
public boolean requireExclusiveLock(Procedure proc) {
TableProcedureInterface tpi = (TableProcedureInterface)proc;
switch (tpi.getTableOperationType()) {
case CREATE:
case DELETE:
case DISABLE:
case ENABLE:
return true;
case EDIT:
// we allow concurrent edit on the NS table
return !tpi.getTableName().equals(TableName.NAMESPACE_TABLE_NAME);
case READ:
return false;
default:
break;
}
throw new UnsupportedOperationException("unexpected type " + tpi.getTableOperationType());
}
private synchronized boolean tryZkSharedLock(final TableLockManager lockManager,
final String purpose) {
// Take zk-read-lock
TableName tableName = getKey();
tableLock = lockManager.readLock(tableName, purpose);
try {
tableLock.acquire();
} catch (IOException e) {
LOG.error("failed acquire read lock on " + tableName, e);
tableLock = null;
return false;
}
return true;
}
private synchronized void releaseZkSharedLock(final TableLockManager lockManager) {
releaseTableLock(lockManager, isSingleSharedLock());
}
private synchronized boolean tryZkExclusiveLock(final TableLockManager lockManager,
final String purpose) {
// Take zk-write-lock
TableName tableName = getKey();
tableLock = lockManager.writeLock(tableName, purpose);
try {
tableLock.acquire();
} catch (IOException e) {
LOG.error("failed acquire write lock on " + tableName, e);
tableLock = null;
return false;
}
return true;
}
private synchronized void releaseZkExclusiveLock(final TableLockManager lockManager) {
releaseTableLock(lockManager, true);
}
private void releaseTableLock(final TableLockManager lockManager, boolean reset) {
for (int i = 0; i < 3; ++i) {
try {
tableLock.release();
if (reset) {
tableLock = null;
}
break;
} catch (IOException e) {
LOG.warn("Could not release the table write-lock", e);
}
}
}
}
/**
* the namespace is currently used just as a rwlock, not as a queue.
* because ns operation are not frequent enough. so we want to avoid
* having to move table queues around for suspend/resume.
*/
private static class NamespaceQueue extends Queue {
public NamespaceQueue(String namespace) {
super(namespace);
}
@Override
public boolean requireExclusiveLock(Procedure proc) {
throw new UnsupportedOperationException();
}
@Override
public void add(final Procedure proc, final boolean addToFront) {
throw new UnsupportedOperationException();
}
@Override
public Procedure peek() {
throw new UnsupportedOperationException();
}
@Override
public Procedure poll() {
throw new UnsupportedOperationException();
}
@Override
public boolean isEmpty() {
throw new UnsupportedOperationException();
}
@Override
public int size() {
throw new UnsupportedOperationException();
}
}
// ============================================================================
// Table Locking Helpers
// ============================================================================
/**
* Try to acquire the exclusive lock on the specified table.
* other operations in the table-queue will be executed after the lock is released.
* @param procedure the procedure trying to acquire the lock
* @param table Table to lock
* @return true if we were able to acquire the lock on the table, otherwise false.
*/
public boolean tryAcquireTableExclusiveLock(final Procedure procedure, final TableName table) {
schedLock.lock();
TableQueue queue = getTableQueue(table);
if (!queue.getNamespaceQueue().trySharedLock()) {
return false;
}
if (!queue.tryExclusiveLock(procedure.getProcId())) {
queue.getNamespaceQueue().releaseSharedLock();
schedLock.unlock();
return false;
}
removeFromRunQueue(tableRunQueue, queue);
schedLock.unlock();
// Zk lock is expensive...
boolean hasXLock = queue.tryZkExclusiveLock(lockManager, procedure.toString());
if (!hasXLock) {
schedLock.lock();
queue.releaseExclusiveLock();
queue.getNamespaceQueue().releaseSharedLock();
addToRunQueue(tableRunQueue, queue);
schedLock.unlock();
}
return hasXLock;
}
/**
* Release the exclusive lock taken with tryAcquireTableWrite()
* @param procedure the procedure releasing the lock
* @param table the name of the table that has the exclusive lock
*/
public void releaseTableExclusiveLock(final Procedure procedure, final TableName table) {
schedLock.lock();
TableQueue queue = getTableQueue(table);
schedLock.unlock();
// Zk lock is expensive...
queue.releaseZkExclusiveLock(lockManager);
schedLock.lock();
queue.releaseExclusiveLock();
queue.getNamespaceQueue().releaseSharedLock();
addToRunQueue(tableRunQueue, queue);
schedLock.unlock();
}
/**
* Try to acquire the shared lock on the specified table.
* other "read" operations in the table-queue may be executed concurrently,
* @param procedure the procedure trying to acquire the lock
* @param table Table to lock
* @return true if we were able to acquire the lock on the table, otherwise false.
*/
public boolean tryAcquireTableSharedLock(final Procedure procedure, final TableName table) {
return tryAcquireTableQueueSharedLock(procedure, table) != null;
}
private TableQueue tryAcquireTableQueueSharedLock(final Procedure procedure,
final TableName table) {
schedLock.lock();
TableQueue queue = getTableQueue(table);
if (!queue.getNamespaceQueue().trySharedLock()) {
return null;
}
if (!queue.trySharedLock()) {
queue.getNamespaceQueue().releaseSharedLock();
schedLock.unlock();
return null;
}
schedLock.unlock();
// Zk lock is expensive...
if (!queue.tryZkSharedLock(lockManager, procedure.toString())) {
schedLock.lock();
queue.releaseSharedLock();
queue.getNamespaceQueue().releaseSharedLock();
schedLock.unlock();
return null;
}
return queue;
}
/**
* Release the shared lock taken with tryAcquireTableRead()
* @param procedure the procedure releasing the lock
* @param table the name of the table that has the shared lock
*/
public void releaseTableSharedLock(final Procedure procedure, final TableName table) {
final TableQueue queue = getTableQueueWithLock(table);
// Zk lock is expensive...
queue.releaseZkSharedLock(lockManager);
schedLock.lock();
queue.releaseSharedLock();
queue.getNamespaceQueue().releaseSharedLock();
schedLock.unlock();
}
/**
* Tries to remove the queue and the table-lock of the specified table.
* If there are new operations pending (e.g. a new create),
* the remove will not be performed.
* @param table the name of the table that should be marked as deleted
* @return true if deletion succeeded, false otherwise meaning that there are
* other new operations pending for that table (e.g. a new create).
*/
protected boolean markTableAsDeleted(final TableName table) {
final ReentrantLock l = schedLock;
l.lock();
try {
TableQueue queue = getTableQueue(table);
if (queue == null) return true;
if (queue.isEmpty() && queue.tryExclusiveLock(0)) {
// remove the table from the run-queue and the map
if (IterableList.isLinked(queue)) {
tableRunQueue.remove(queue);
}
// Remove the table lock
try {
lockManager.tableDeleted(table);
} catch (IOException e) {
LOG.warn("Received exception from TableLockManager.tableDeleted:", e); //not critical
}
removeTableQueue(table);
} else {
// TODO: If there are no create, we can drop all the other ops
return false;
}
} finally {
l.unlock();
}
return true;
}
// ============================================================================
// Namespace Locking Helpers
// ============================================================================
/**
* Try to acquire the exclusive lock on the specified namespace.
* @see #releaseNamespaceExclusiveLock(Procedure,String)
* @param procedure the procedure trying to acquire the lock
* @param nsName Namespace to lock
* @return true if we were able to acquire the lock on the namespace, otherwise false.
*/
public boolean tryAcquireNamespaceExclusiveLock(final Procedure procedure, final String nsName) {
schedLock.lock();
try {
TableQueue tableQueue = getTableQueue(TableName.NAMESPACE_TABLE_NAME);
if (!tableQueue.trySharedLock()) return false;
NamespaceQueue nsQueue = getNamespaceQueue(nsName);
boolean hasLock = nsQueue.tryExclusiveLock(procedure.getProcId());
if (!hasLock) {
tableQueue.releaseSharedLock();
}
return hasLock;
} finally {
schedLock.unlock();
}
}
/**
* Release the exclusive lock
* @see #tryAcquireNamespaceExclusiveLock(Procedure,String)
* @param procedure the procedure releasing the lock
* @param nsName the namespace that has the exclusive lock
*/
public void releaseNamespaceExclusiveLock(final Procedure procedure, final String nsName) {
schedLock.lock();
try {
TableQueue tableQueue = getTableQueue(TableName.NAMESPACE_TABLE_NAME);
tableQueue.releaseSharedLock();
NamespaceQueue queue = getNamespaceQueue(nsName);
queue.releaseExclusiveLock();
} finally {
schedLock.unlock();
}
}
// ============================================================================
// Server Locking Helpers
// ============================================================================
/**
* Try to acquire the exclusive lock on the specified server.
* @see #releaseServerExclusiveLock(Procedure,ServerName)
* @param procedure the procedure trying to acquire the lock
* @param serverName Server to lock
* @return true if we were able to acquire the lock on the server, otherwise false.
*/
public boolean tryAcquireServerExclusiveLock(final Procedure procedure,
final ServerName serverName) {
schedLock.lock();
try {
ServerQueue queue = getServerQueue(serverName);
if (queue.tryExclusiveLock(procedure.getProcId())) {
removeFromRunQueue(serverRunQueue, queue);
return true;
}
} finally {
schedLock.unlock();
}
return false;
}
/**
* Release the exclusive lock
* @see #tryAcquireServerExclusiveLock(Procedure,ServerName)
* @param procedure the procedure releasing the lock
* @param serverName the server that has the exclusive lock
*/
public void releaseServerExclusiveLock(final Procedure procedure,
final ServerName serverName) {
schedLock.lock();
try {
ServerQueue queue = getServerQueue(serverName);
queue.releaseExclusiveLock();
addToRunQueue(serverRunQueue, queue);
} finally {
schedLock.unlock();
}
}
/**
* Try to acquire the shared lock on the specified server.
* @see #releaseServerSharedLock(Procedure,ServerName)
* @param procedure the procedure releasing the lock
* @param serverName Server to lock
* @return true if we were able to acquire the lock on the server, otherwise false.
*/
public boolean tryAcquireServerSharedLock(final Procedure procedure,
final ServerName serverName) {
return getServerQueueWithLock(serverName).trySharedLock();
}
/**
* Release the shared lock taken
* @see #tryAcquireServerSharedLock(Procedure,ServerName)
* @param procedure the procedure releasing the lock
* @param serverName the server that has the shared lock
*/
public void releaseServerSharedLock(final Procedure procedure,
final ServerName serverName) {
getServerQueueWithLock(serverName).releaseSharedLock();
}
// ============================================================================
// Generic Helpers
// ============================================================================
private static interface QueueInterface {
boolean isAvailable();
boolean isEmpty();
int size();
void add(Procedure proc, boolean addFront);
boolean requireExclusiveLock(Procedure proc);
Procedure peek();
Procedure poll();
boolean isSuspended();
}
private static abstract class Queue> implements QueueInterface {
private Queue avlRight = null;
private Queue avlLeft = null;
private int avlHeight = 1;
private Queue iterNext = null;
private Queue iterPrev = null;
private boolean suspended = false;
private long exclusiveLockProcIdOwner = Long.MIN_VALUE;
private int sharedLock = 0;
private final TKey key;
private final int priority;
public Queue(TKey key) {
this(key, 1);
}
public Queue(TKey key, int priority) {
this.key = key;
this.priority = priority;
}
protected TKey getKey() {
return key;
}
protected int getPriority() {
return priority;
}
/**
* True if the queue is not in the run-queue and it is owned by an event.
*/
public boolean isSuspended() {
return suspended;
}
protected boolean setSuspended(boolean isSuspended) {
if (this.suspended == isSuspended) return false;
this.suspended = isSuspended;
return true;
}
// ======================================================================
// Read/Write Locking helpers
// ======================================================================
public synchronized boolean isLocked() {
return hasExclusiveLock() || sharedLock > 0;
}
public synchronized boolean hasExclusiveLock() {
return this.exclusiveLockProcIdOwner != Long.MIN_VALUE;
}
public synchronized boolean trySharedLock() {
if (hasExclusiveLock()) return false;
sharedLock++;
return true;
}
public synchronized void releaseSharedLock() {
sharedLock--;
}
protected synchronized boolean isSingleSharedLock() {
return sharedLock == 1;
}
public synchronized boolean tryExclusiveLock(long procIdOwner) {
assert procIdOwner != Long.MIN_VALUE;
if (isLocked()) return false;
exclusiveLockProcIdOwner = procIdOwner;
return true;
}
public synchronized void releaseExclusiveLock() {
exclusiveLockProcIdOwner = Long.MIN_VALUE;
}
// This should go away when we have the new AM and its events
// and we move xlock to the lock-event-queue.
public synchronized boolean isAvailable() {
return !hasExclusiveLock() && !isEmpty();
}
// ======================================================================
// Generic Helpers
// ======================================================================
public int compareKey(TKey cmpKey) {
return key.compareTo(cmpKey);
}
public int compareTo(Queue other) {
return compareKey(other.key);
}
@Override
public String toString() {
return String.format("%s(%s)", getClass().getSimpleName(), key);
}
}
// ======================================================================
// Helper Data Structures
// ======================================================================
private static abstract class QueueImpl> extends Queue {
private final ArrayDeque runnables = new ArrayDeque();
public QueueImpl(TKey key) {
super(key);
}
public QueueImpl(TKey key, int priority) {
super(key, priority);
}
public void add(final Procedure proc, final boolean addToFront) {
if (addToFront) {
addFront(proc);
} else {
addBack(proc);
}
}
protected void addFront(final Procedure proc) {
runnables.addFirst(proc);
}
protected void addBack(final Procedure proc) {
runnables.addLast(proc);
}
public Procedure peek() {
return runnables.peek();
}
@Override
public Procedure poll() {
return runnables.poll();
}
@Override
public boolean isEmpty() {
return runnables.isEmpty();
}
public int size() {
return runnables.size();
}
}
private static class FairQueue> {
private final int quantum;
private Queue currentQueue = null;
private Queue queueHead = null;
private int currentQuantum = 0;
public FairQueue() {
this(1);
}
public FairQueue(int quantum) {
this.quantum = quantum;
}
public void add(Queue queue) {
queueHead = IterableList.append(queueHead, queue);
if (currentQueue == null) setNextQueue(queueHead);
}
public void remove(Queue queue) {
Queue nextQueue = queue.iterNext;
queueHead = IterableList.remove(queueHead, queue);
if (currentQueue == queue) {
setNextQueue(queueHead != null ? nextQueue : null);
}
}
public Queue poll() {
if (currentQuantum == 0) {
if (!nextQueue()) {
return null; // nothing here
}
currentQuantum = calculateQuantum(currentQueue) - 1;
} else {
currentQuantum--;
}
// This should go away when we have the new AM and its events
if (!currentQueue.isAvailable()) {
Queue lastQueue = currentQueue;
do {
if (!nextQueue())
return null;
} while (currentQueue != lastQueue && !currentQueue.isAvailable());
currentQuantum = calculateQuantum(currentQueue) - 1;
}
return currentQueue;
}
private boolean nextQueue() {
if (currentQueue == null) return false;
currentQueue = currentQueue.iterNext;
return currentQueue != null;
}
private void setNextQueue(Queue queue) {
currentQueue = queue;
if (queue != null) {
currentQuantum = calculateQuantum(currentQueue);
} else {
currentQuantum = 0;
}
}
private int calculateQuantum(final Queue queue) {
return Math.max(1, queue.getPriority() * quantum); // TODO
}
}
private static class AvlTree {
public static > Queue get(Queue root, T key) {
while (root != null) {
int cmp = root.compareKey(key);
if (cmp > 0) {
root = root.avlLeft;
} else if (cmp < 0) {
root = root.avlRight;
} else {
return root;
}
}
return null;
}
public static > Queue getFirst(Queue root) {
if (root != null) {
while (root.avlLeft != null) {
root = root.avlLeft;
}
}
return root;
}
public static > Queue getLast(Queue root) {
if (root != null) {
while (root.avlRight != null) {
root = root.avlRight;
}
}
return root;
}
public static > Queue insert(Queue root, Queue node) {
if (root == null) return node;
if (node.compareTo(root) < 0) {
root.avlLeft = insert(root.avlLeft, node);
} else {
root.avlRight = insert(root.avlRight, node);
}
return balance(root);
}
private static > Queue removeMin(Queue p) {
if (p.avlLeft == null)
return p.avlRight;
p.avlLeft = removeMin(p.avlLeft);
return balance(p);
}
public static > Queue remove(Queue root, T key) {
if (root == null) return null;
int cmp = root.compareKey(key);
if (cmp == 0) {
Queue q = root.avlLeft;
Queue r = root.avlRight;
if (r == null) return q;
Queue min = getFirst(r);
min.avlRight = removeMin(r);
min.avlLeft = q;
return balance(min);
} else if (cmp > 0) {
root.avlLeft = remove(root.avlLeft, key);
} else /* if (cmp < 0) */ {
root.avlRight = remove(root.avlRight, key);
}
return balance(root);
}
private static > Queue balance(Queue p) {
fixHeight(p);
int balance = balanceFactor(p);
if (balance == 2) {
if (balanceFactor(p.avlRight) < 0) {
p.avlRight = rotateRight(p.avlRight);
}
return rotateLeft(p);
} else if (balance == -2) {
if (balanceFactor(p.avlLeft) > 0) {
p.avlLeft = rotateLeft(p.avlLeft);
}
return rotateRight(p);
}
return p;
}
private static > Queue rotateRight(Queue p) {
Queue q = p.avlLeft;
p.avlLeft = q.avlRight;
q.avlRight = p;
fixHeight(p);
fixHeight(q);
return q;
}
private static > Queue rotateLeft(Queue q) {
Queue p = q.avlRight;
q.avlRight = p.avlLeft;
p.avlLeft = q;
fixHeight(q);
fixHeight(p);
return p;
}
private static > void fixHeight(Queue node) {
int heightLeft = height(node.avlLeft);
int heightRight = height(node.avlRight);
node.avlHeight = 1 + Math.max(heightLeft, heightRight);
}
private static > int height(Queue node) {
return node != null ? node.avlHeight : 0;
}
private static > int balanceFactor(Queue node) {
return height(node.avlRight) - height(node.avlLeft);
}
}
private static class IterableList {
public static > Queue prepend(Queue head, Queue node) {
assert !isLinked(node) : node + " is already linked";
if (head != null) {
Queue tail = head.iterPrev;
tail.iterNext = node;
head.iterPrev = node;
node.iterNext = head;
node.iterPrev = tail;
} else {
node.iterNext = node;
node.iterPrev = node;
}
return node;
}
public static > Queue append(Queue head, Queue node) {
assert !isLinked(node) : node + " is already linked";
if (head != null) {
Queue tail = head.iterPrev;
tail.iterNext = node;
node.iterNext = head;
node.iterPrev = tail;
head.iterPrev = node;
return head;
}
node.iterNext = node;
node.iterPrev = node;
return node;
}
public static > Queue appendList(Queue head, Queue otherHead) {
if (head == null) return otherHead;
if (otherHead == null) return head;
Queue tail = head.iterPrev;
Queue otherTail = otherHead.iterPrev;
tail.iterNext = otherHead;
otherHead.iterPrev = tail;
otherTail.iterNext = head;
head.iterPrev = otherTail;
return head;
}
private static > Queue remove(Queue head, Queue node) {
assert isLinked(node) : node + " is not linked";
if (node != node.iterNext) {
node.iterPrev.iterNext = node.iterNext;
node.iterNext.iterPrev = node.iterPrev;
head = (head == node) ? node.iterNext : head;
} else {
head = null;
}
node.iterNext = null;
node.iterPrev = null;
return head;
}
private static > boolean isLinked(Queue node) {
return node.iterPrev != null && node.iterNext != null;
}
}
}