Add snapshottable collection lock

This commit is contained in:
Andrea Cavalli 2021-01-24 02:40:12 +01:00
parent 5f0e5419c9
commit 27ea0deaed
4 changed files with 568 additions and 4 deletions

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@ -0,0 +1,372 @@
package org.warp.commonutils.locks;
import it.cavallium.concurrentlocks.ReadWriteUpdateLock;
import java.util.Objects;
import java.util.Set;
import org.jetbrains.annotations.NotNull;
/**
* Fine-grained locking on data or on the entire collection for a snapshottable collection
* @param <T>
*/
public class SnapshottableCollectionLock<T> {
private final TransitReadWriteLock fullLock;
private final TransitReadWriteLock dataLock;
private final Striped<ReadWriteUpdateLock> transactionLock;
public SnapshottableCollectionLock(int stripedSize) {
this.transactionLock = Striped.readWriteUpdateLock(stripedSize);
this.fullLock = new TransitReadWriteLock();
this.dataLock = new TransitReadWriteLock();
}
public enum DataLockType {
READ,
/**
* "Update" allow reads but blocks writes and other updates.
*/
UPDATE,
WRITE
}
public enum FullLockType {
/** <p>This lock is a read lock for "full", nothing for "data"</p>
* <p>Useful for coarse iterators</p>
*
* <ul>
* <li>full<ul>
* <li>read: allow</li>
* <li>write: <u>deny</u></li>
* </ul></li>
* <li>data<ul>
* <li>read/update: allow</li>
* <li>write: allow</li>
* </ul></li>
* </ul>
*/
DENY_ONLY_FULL_WRITE,
/** <p>This lock is a read lock for "full" and a read lock for "data"</p>
*
* <ul>
* <li>full<ul>
* <li>read: allow</li>
* <li>write: <u>deny</u></li>
* </ul></li>
* <li>data<ul>
* <li>read/update: allow</li>
* <li>write: <u>deny</u></li>
* </ul></li>
* </ul>
*/
ALLOW_ONLY_READ,
/** <p>This lock is a write lock for "full" and a read lock for "data"</p>
*
* <ul>
* <li>full<ul>
* <li>read: <u>deny</u></li>
* <li>write: <u>deny</u></li>
* </ul></li>
* <li>data<ul>
* <li>read/update: allow</li>
* <li>write: <u>deny</u></li>
* </ul></li>
* </ul>
*/
ALLOW_ONLY_ITEMS_READ,
/** <p>This lock is a read lock for "full" and a write lock for "data"</p>
*
* <ul>
* <li>full<ul>
* <li>read: allow</li>
* <li>write: <u>deny</u></li>
* </ul></li>
* <li>data<ul>
* <li>read/update: <u>deny</u></li>
* <li>write: <u>deny</u></li>
* </ul></li>
* </ul>
*/
ALLOW_ONLY_FULL_READ,
/** <p>This lock is a write lock for "full" and a write lock for "data"</p>
*
* <ul>
* <li>full<ul>
* <li>read: <u>deny</u></li>
* <li>write: <u>deny</u></li>
* </ul></li>
* <li>data<ul>
* <li>read/update: <u>deny</u></li>
* <li>write: <u>deny</u></li>
* </ul></li>
* </ul>
*/
EXCLUSIVE;
public static final Set<FullLockType> READ_FULL_TYPES = Set.of(
DENY_ONLY_FULL_WRITE,
ALLOW_ONLY_READ,
ALLOW_ONLY_FULL_READ
);
public static final Set<FullLockType> WRITE_FULL_TYPES = Set.of(ALLOW_ONLY_ITEMS_READ, EXCLUSIVE);
public static final Set<FullLockType> READ_DATA_TYPES = Set.of(ALLOW_ONLY_READ, ALLOW_ONLY_ITEMS_READ);
public static final Set<FullLockType> WRITE_DATA_TYPES = Set.of(ALLOW_ONLY_FULL_READ, EXCLUSIVE);
public static final Set<FullLockType> NOOP_DATA_TYPES = Set.of(DENY_ONLY_FULL_WRITE);
}
public void fullLock(Object snapshot, FullLockType fullLockMode) {
if (snapshot == null) {
// Transit on full locks
switch (fullLockMode) {
case DENY_ONLY_FULL_WRITE:
case ALLOW_ONLY_READ:
case ALLOW_ONLY_FULL_READ:
fullLock.startTransitRead();
break;
case ALLOW_ONLY_ITEMS_READ:
case EXCLUSIVE:
break;
default:
throw new IllegalStateException("Unexpected value: " + fullLockMode);
}
// Manage full locks
switch (fullLockMode) {
case DENY_ONLY_FULL_WRITE:
case ALLOW_ONLY_READ:
case ALLOW_ONLY_FULL_READ:
fullLock.disallowTransitWrite();
break;
case ALLOW_ONLY_ITEMS_READ:
case EXCLUSIVE:
fullLock.disallowTransit();
break;
default:
throw new IllegalStateException("Unexpected value: " + fullLockMode);
}
// Manage data locks
switch (fullLockMode) {
case DENY_ONLY_FULL_WRITE:
break;
case ALLOW_ONLY_READ:
case ALLOW_ONLY_ITEMS_READ:
dataLock.disallowTransitWrite();
break;
case ALLOW_ONLY_FULL_READ:
case EXCLUSIVE:
dataLock.disallowTransit();
break;
default:
throw new IllegalStateException("Unexpected value: " + fullLockMode);
}
}
}
public void fullUnlock(Object snapshot, FullLockType fullLockMode) {
if (snapshot == null) {
// Manage full locks
switch (fullLockMode) {
case DENY_ONLY_FULL_WRITE:
case ALLOW_ONLY_READ:
case ALLOW_ONLY_FULL_READ:
fullLock.reAllowTransitWrite();
break;
case ALLOW_ONLY_ITEMS_READ:
case EXCLUSIVE:
fullLock.reAllowTransit();
break;
default:
throw new IllegalStateException("Unexpected value: " + fullLockMode);
}
// Transit on full locks
switch (fullLockMode) {
case DENY_ONLY_FULL_WRITE:
case ALLOW_ONLY_READ:
case ALLOW_ONLY_FULL_READ:
fullLock.endTransitRead();
break;
case ALLOW_ONLY_ITEMS_READ:
case EXCLUSIVE:
break;
default:
throw new IllegalStateException("Unexpected value: " + fullLockMode);
}
// Manage data locks
switch (fullLockMode) {
case DENY_ONLY_FULL_WRITE:
break;
case ALLOW_ONLY_READ:
case ALLOW_ONLY_ITEMS_READ:
dataLock.reAllowTransitWrite();
break;
case ALLOW_ONLY_FULL_READ:
case EXCLUSIVE:
dataLock.reAllowTransit();
break;
default:
throw new IllegalStateException("Unexpected value: " + fullLockMode);
}
}
}
private void partialLockKey(DataLockType dataLockMode, ReadWriteUpdateLock lock) {
switch (dataLockMode) {
case READ:
dataLock.startTransitRead();
lock.readLock().lock();
break;
//todo: check carefully if an update lock can lock dataLock only for data read.
// If it can, replace startTransitWrite with startTransitRead here.
case UPDATE:
dataLock.startTransitWrite();
lock.updateLock().lock();
break;
case WRITE:
dataLock.startTransitWrite();
lock.writeLock().lock();
break;
}
}
private void partialUnlockKey(DataLockType dataLockMode, ReadWriteUpdateLock lock) {
switch (dataLockMode) {
case READ:
lock.readLock().unlock();
dataLock.endTransitRead();
break;
//todo: check carefully if an update lock can lock dataLock only for data read.
// If it can, replace startTransitWrite with startTransitRead here.
case UPDATE:
lock.updateLock().unlock();
dataLock.endTransitWrite();
break;
case WRITE:
lock.writeLock().unlock();
dataLock.endTransitWrite();
break;
}
}
private void partialLockKeyUpgrade(DataLockType dataLockMode, ReadWriteUpdateLock lock) {
switch (dataLockMode) {
case READ:
lock.readLock().lock();
break;
case UPDATE:
lock.updateLock().lock();
break;
case WRITE:
lock.writeLock().lock();
break;
}
}
private void partialUnlockKeyUpgrade(DataLockType dataLockMode, ReadWriteUpdateLock lock) {
switch (dataLockMode) {
case READ:
lock.readLock().unlock();
break;
case UPDATE:
lock.writeLock().unlock();
break;
case WRITE:
lock.writeLock().unlock();
break;
}
}
public void dataLock(Object snapshot, DataLockType dataLockMode, @NotNull T key) {
if (snapshot == null) {
Objects.requireNonNull(key, () -> "Lock key must not be null");
var lock = transactionLock.get(key);
partialLockKey(dataLockMode, lock);
}
}
public void dataLockAt(Object snapshot, DataLockType dataLockMode, int index) {
if (snapshot == null) {
var lock = transactionLock.getAt(index);
partialLockKey(dataLockMode, lock);
}
}
public void dataLockUpgrade(Object snapshot, DataLockType dataLockMode, @NotNull T key) {
if (snapshot == null) {
Objects.requireNonNull(key, () -> "Lock key must not be null");
var lock = transactionLock.get(key);
partialLockKeyUpgrade(dataLockMode, lock);
}
}
public void dataLockUpgradeAt(Object snapshot, DataLockType dataLockMode, int index) {
if (snapshot == null) {
var lock = transactionLock.getAt(index);
partialLockKeyUpgrade(dataLockMode, lock);
}
}
public void dataUnlock(Object snapshot, DataLockType dataLockMode, @NotNull T key) {
if (snapshot == null) {
Objects.requireNonNull(key, () -> "Lock key must not be null");
var lock = transactionLock.get(key);
partialUnlockKey(dataLockMode, lock);
}
}
public void dataUnlockAt(Object snapshot, DataLockType dataLockMode, int index) {
if (snapshot == null) {
var lock = transactionLock.getAt(index);
partialUnlockKey(dataLockMode, lock);
}
}
public void dataUnlockUpgrade(Object snapshot, DataLockType dataLockMode, @NotNull T key) {
if (snapshot == null) {
Objects.requireNonNull(key, () -> "Lock key must not be null");
var lock = transactionLock.get(key);
partialUnlockKeyUpgrade(dataLockMode, lock);
}
}
public void dataUnlockUpgradeAt(Object snapshot, DataLockType dataLockMode, @NotNull int index) {
if (snapshot == null) {
var lock = transactionLock.getAt(index);
partialUnlockKeyUpgrade(dataLockMode, lock);
}
}
public void dataLockMulti(Object snapshot, DataLockType dataLockMode, @NotNull Iterable<? extends T> key) {
if (snapshot == null) {
Objects.requireNonNull(key, () -> "Lock key must not be null");
for (ReadWriteUpdateLock lock : transactionLock.bulkGet(key)) {
partialLockKey(dataLockMode, lock);
}
}
}
public void dataLockAtMulti(Object snapshot, DataLockType dataLockMode, @NotNull Iterable<Integer> key) {
if (snapshot == null) {
Objects.requireNonNull(key, () -> "Lock key must not be null");
for (ReadWriteUpdateLock lock : transactionLock.bulkGetAt(key)) {
partialLockKey(dataLockMode, lock);
}
}
}
public void dataUnlockMulti(Object snapshot, DataLockType dataLockMode, @NotNull Iterable<? extends T> key) {
if (snapshot == null) {
Objects.requireNonNull(key, () -> "Lock key must not be null");
for (ReadWriteUpdateLock lock : transactionLock.bulkGetInverse(key)) {
partialUnlockKey(dataLockMode, lock);
}
}
}
public void dataUnlockAtMulti(Object snapshot, DataLockType dataLockMode, @NotNull Iterable<Integer> key) {
if (snapshot == null) {
Objects.requireNonNull(key, () -> "Lock key must not be null");
for (ReadWriteUpdateLock lock : transactionLock.bulkGetAtInverse(key)) {
partialUnlockKey(dataLockMode, lock);
}
}
}
}

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@ -134,6 +134,16 @@ public abstract class Striped<L> {
* #get(Object)}; may contain duplicates), in an increasing index order.
*/
public Iterable<L> bulkGet(Iterable<?> keys) {
return Collections.unmodifiableList(bulkGet_(keys));
}
public Iterable<L> bulkGetInverse(Iterable<?> keys) {
var list = bulkGet_(keys);
Collections.reverse(list);
return Collections.unmodifiableList(list);
}
private List<L> bulkGet_(Iterable<?> keys) {
// Initially using the array to store the keys, then reusing it to store the respective L's
final Object[] array = Iterables.toArray(keys, Object.class);
if (array.length == 0) {
@ -174,8 +184,62 @@ public abstract class Striped<L> {
* be garbage collected after locking them, ending up in a huge mess.
*/
@SuppressWarnings("unchecked") // we carefully replaced all keys with their respective L's
List<L> asList = (List<L>) Arrays.asList(array);
return Collections.unmodifiableList(asList);
List<L> asList = (List<L>) Arrays.asList(array);
return asList;
}
public Iterable<L> bulkGetAt(Iterable<Integer> keys) {
return Collections.unmodifiableList(bulkGetAt_(keys));
}
public Iterable<L> bulkGetAtInverse(Iterable<Integer> keys) {
var list = bulkGetAt_(keys);
Collections.reverse(list);
return Collections.unmodifiableList(list);
}
private List<L> bulkGetAt_(Iterable<Integer> keys) {
// Initially using the array to store the keys, then reusing it to store the respective L's
final Object[] array = Iterables.toArray(keys, Object.class);
if (array.length == 0) {
return ImmutableList.of();
}
int[] stripes = new int[array.length];
for (int i = 0; i < array.length; i++) {
stripes[i] = (int) array[i];
}
Arrays.sort(stripes);
// optimize for runs of identical stripes
int previousStripe = stripes[0];
array[0] = getAt(previousStripe);
for (int i = 1; i < array.length; i++) {
int currentStripe = stripes[i];
if (currentStripe == previousStripe) {
array[i] = array[i - 1];
} else {
array[i] = getAt(currentStripe);
previousStripe = currentStripe;
}
}
/*
* Note that the returned Iterable holds references to the returned stripes, to avoid
* error-prone code like:
*
* Striped<Lock> stripedLock = Striped.lazyWeakXXX(...)'
* Iterable<Lock> locks = stripedLock.bulkGet(keys);
* for (Lock lock : locks) {
* lock.lock();
* }
* operation();
* for (Lock lock : locks) {
* lock.unlock();
* }
*
* If we only held the int[] stripes, translating it on the fly to L's, the original locks might
* be garbage collected after locking them, ending up in a huge mess.
*/
@SuppressWarnings("unchecked") // we carefully replaced all keys with their respective L's
List<L> asList = (List<L>) Arrays.asList(array);
return asList;
}
// Static factories

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@ -1,4 +1,4 @@
package org.warp.commonutils.functional.org.warp.commonutils.locks;
package org.warp.commonutils.locks;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;
@ -8,7 +8,6 @@ import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.Timeout;
import org.warp.commonutils.locks.LeftRightLock;
public class LeftRightLockTest {

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@ -0,0 +1,129 @@
package org.warp.commonutils.locks;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
import org.warp.commonutils.locks.SnapshottableCollectionLock.DataLockType;
import org.warp.commonutils.locks.SnapshottableCollectionLock.FullLockType;
public class SnapshottableCollectionLockTest {
@Test
public void testNoop() {
var lock = new SnapshottableCollectionLock<Long>(50);
checkSituation(lock, true, true, true, true);
}
@Test
public void testDenyOnlyFullWrite() {
var lock = new SnapshottableCollectionLock<Long>(50);
lock.fullLock(null, FullLockType.DENY_ONLY_FULL_WRITE);
checkSituation(lock, true, false, true, true);
lock.fullUnlock(null, FullLockType.DENY_ONLY_FULL_WRITE);
}
@Test
public void testAllowOnlyRead() {
var lock = new SnapshottableCollectionLock<Long>(50);
lock.fullLock(null, FullLockType.ALLOW_ONLY_READ);
checkSituation(lock, true, false, true, false);
lock.fullUnlock(null, FullLockType.ALLOW_ONLY_READ);
}
@Test
public void testAllowOnlyItemsRead() {
var lock = new SnapshottableCollectionLock<Long>(50);
lock.fullLock(null, FullLockType.ALLOW_ONLY_ITEMS_READ);
checkSituation(lock, false, false, true, false);
lock.fullUnlock(null, FullLockType.ALLOW_ONLY_ITEMS_READ);
}
@Test
public void testAllowOnlyFullRead() {
var lock = new SnapshottableCollectionLock<Long>(50);
lock.fullLock(null, FullLockType.ALLOW_ONLY_FULL_READ);
checkSituation(lock, true, false, false, false);
lock.fullUnlock(null, FullLockType.ALLOW_ONLY_FULL_READ);
}
@Test
public void testExclusive() {
var lock = new SnapshottableCollectionLock<Long>(50);
lock.fullLock(null, FullLockType.EXCLUSIVE);
checkSituation(lock, false, false, false, false);
lock.fullUnlock(null, FullLockType.EXCLUSIVE);
}
private void checkSituation(SnapshottableCollectionLock<Long> lock, boolean fullReadAllow, boolean fullWriteAllow, boolean dataReadAllow, boolean dataWriteAllow) {
for (FullLockType readFullType : FullLockType.READ_FULL_TYPES) {
if (fullReadAllow) {
Assertions.assertDoesNotThrow(() -> {
CompletableFuture.runAsync(() -> {
lock.fullLock(null, readFullType);
lock.fullUnlock(null, readFullType);
}).get(1, TimeUnit.SECONDS);
});
} else {
Assertions.assertThrows(TimeoutException.class, () -> {
CompletableFuture.runAsync(() -> {
lock.fullLock(null, readFullType);
lock.fullUnlock(null, readFullType);
}).get(50, TimeUnit.MILLISECONDS);
});
}
}
for (FullLockType writeFullType : FullLockType.WRITE_FULL_TYPES) {
if (fullWriteAllow) {
Assertions.assertDoesNotThrow(() -> {
CompletableFuture.runAsync(() -> {
lock.fullLock(null, writeFullType);
lock.fullUnlock(null, writeFullType);
}).get(1, TimeUnit.SECONDS);
});
} else {
Assertions.assertThrows(TimeoutException.class, () -> {
CompletableFuture.runAsync(() -> {
lock.fullLock(null, writeFullType);
lock.fullUnlock(null, writeFullType);
}).get(50, TimeUnit.MILLISECONDS);
});
}
}
if (dataReadAllow) {
Assertions.assertDoesNotThrow(() -> {
CompletableFuture.runAsync(() -> {
lock.dataLock(null, DataLockType.READ, 1L);
lock.dataUnlock(null, DataLockType.READ, 1L);
}).get(1, TimeUnit.SECONDS);
});
} else {
Assertions.assertThrows(TimeoutException.class, () -> {
CompletableFuture.runAsync(() -> {
lock.dataLock(null, DataLockType.READ, 1L);
lock.dataUnlock(null, DataLockType.READ, 1L);
}).get(50, TimeUnit.MILLISECONDS);
});
}
if (dataWriteAllow) {
Assertions.assertDoesNotThrow(() -> {
CompletableFuture.runAsync(() -> {
lock.dataLock(null, DataLockType.WRITE, 1L);
lock.dataUnlock(null, DataLockType.WRITE, 1L);
}).get(1, TimeUnit.SECONDS);
});
} else {
Assertions.assertThrows(TimeoutException.class, () -> {
CompletableFuture.runAsync(() -> {
lock.dataLock(null, DataLockType.WRITE, 1L);
lock.dataUnlock(null, DataLockType.WRITE, 1L);
}).get(50, TimeUnit.MILLISECONDS);
});
}
}
}