diff --git a/README.md b/README.md index 454a7ef6e..588d3802d 100644 --- a/README.md +++ b/README.md @@ -1556,8 +1556,8 @@ enough to - Backup all changes to ChronicleMap to some durable storage, e. g. SQL database - Perform multi-ChronicleMap operations correctly in concurrent environment, by acquiring locks on all ChronicleMaps before updating them. - - Perform multi-key operations on a single ChronicleMap correctly in concurrent environment, - by acquiring locks on all keys before updating the entries SOON + - Perform multi-key operations on a single ChronicleMap correctly in concurrent environment, + by acquiring locks on all keys before updating the entries - Define own replication/reconciliation logic for distributed ChronicleMaps ## Examples @@ -1917,6 +1917,125 @@ ChronicleMap> map1 = ChronicleMapBuilder .create(); ``` +### Undirected graph + +Using nested contexts: + +```java + public static boolean addEdge( + ChronicleMap> graph, int source, int target) { + if (source == target) + throw new IllegalArgumentException("loops are forbidden"); + + try (ExternalMapQueryContext, ?> sc = graph.queryContext(source)) { + sc.updateLock().lock(); + try (ExternalMapQueryContext, ?> tc = + graph.queryContext(target)) { + tc.updateLock().lock(); + MapEntry> sEntry = sc.entry(); + if (sEntry != null) { + MapEntry> tEntry = tc.entry(); + if (tEntry != null) { + return addEdgeBothPresent(sc, sEntry, source, tc, tEntry, target); + } else { + addEdgePresentAbsent(sc, sEntry, source, tc, target); + return true; + } + } else { + MapEntry> tEntry = tc.entry(); + if (tEntry != null) { + addEdgePresentAbsent(tc, tEntry, target, sc, source); + } else { + addEdgeBothAbsent(sc, source, tc, target); + } + return true; + } + } + } + } + + private static boolean addEdgeBothPresent( + MapQueryContext, ?> sc, + @NotNull MapEntry> sEntry, int source, + MapQueryContext, ?> tc, + @NotNull MapEntry> tEntry, int target) { + Set sNeighbours = sEntry.value().get(); + if (sNeighbours.add(target)) { + Set tNeighbours = tEntry.value().get(); + boolean added = tNeighbours.add(source); + assert added; + sEntry.doReplaceValue(sc.wrapValueAsData(sNeighbours)); + tEntry.doReplaceValue(tc.wrapValueAsData(tNeighbours)); + return true; + } else { + return false; + } + } + + private static void addEdgePresentAbsent( + MapQueryContext, ?> sc, + @NotNull MapEntry> sEntry, int source, + MapQueryContext, ?> tc, int target) { + Set sNeighbours = sEntry.value().get(); + boolean added = sNeighbours.add(target); + assert added; + sEntry.doReplaceValue(sc.wrapValueAsData(sNeighbours)); + + addEdgeOneSide(tc, source); + } + + private static void addEdgeBothAbsent(MapQueryContext, ?> sc, int source, + MapQueryContext, ?> tc, int target) { + addEdgeOneSide(sc, target); + addEdgeOneSide(tc, source); + } + + private static void addEdgeOneSide(MapQueryContext, ?> tc, int source) { + Set tNeighbours = new HashSet<>(); + tNeighbours.add(source); + MapAbsentEntry> tAbsentEntry = tc.absentEntry(); + assert tAbsentEntry != null; + tAbsentEntry.doInsert(tc.wrapValueAsData(tNeighbours)); + } + + public static boolean removeEdge( + ChronicleMap> graph, int source, int target) { + try (ExternalMapQueryContext, ?> sc = graph.queryContext(source)) { + sc.updateLock().lock(); + MapEntry> sEntry = sc.entry(); + if (sEntry == null) + return false; + Set sNeighbours = sEntry.value().get(); + if (!sNeighbours.remove(target)) + return false; + try (ExternalMapQueryContext, ?> tc = + graph.queryContext(target)) { + tc.updateLock().lock(); + MapEntry> tEntry = tc.entry(); + if (tEntry == null) + throw new IllegalStateException("target node should be present in the graph"); + Set tNeighbours = tEntry.value().get(); + if (!tNeighbours.remove(source)) + throw new IllegalStateException("the target node have an edge to the source"); + sEntry.doReplaceValue(sc.wrapValueAsData(sNeighbours)); + tEntry.doReplaceValue(tc.wrapValueAsData(tNeighbours)); + return true; + } + } + } +``` + +Usage: +```java +ChronicleMap> graph = ChronicleMapBuilder + .of(Integer.class, (Class>) (Class) Set.class) + .entries(100) + .averageValueSize(1000) + .create(); + +addEdge(graph, 1, 2); +removeEdge(graph, 1, 2); +``` # Performance Topics diff --git a/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/ReadLock.java b/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/ReadLock.java index 20bc158e4..4d47b9d32 100644 --- a/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/ReadLock.java +++ b/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/ReadLock.java @@ -44,7 +44,9 @@ public class ReadLock implements InterProcessLock { @Override public void lock() { if (s.localLockState == UNLOCKED) { - s.segmentHeader.readLock(s.segmentHeaderAddress); + if (s.readZero() && s.updateZero() && s.writeZero()) + s.segmentHeader.readLock(s.segmentHeaderAddress); + s.incrementRead(); s.setLocalLockState(READ_LOCKED); } } @@ -52,7 +54,9 @@ public class ReadLock implements InterProcessLock { @Override public void lockInterruptibly() throws InterruptedException { if (s.localLockState == UNLOCKED) { - s.segmentHeader.readLockInterruptibly(s.segmentHeaderAddress); + if (s.readZero() && s.updateZero() && s.writeZero()) + s.segmentHeader.readLockInterruptibly(s.segmentHeaderAddress); + s.incrementRead(); s.setLocalLockState(READ_LOCKED); } } @@ -60,7 +64,9 @@ public class ReadLock implements InterProcessLock { @Override public boolean tryLock() { if (s.localLockState == UNLOCKED) { - if (s.segmentHeader.tryReadLock(s.segmentHeaderAddress)) { + if (!s.readZero() || !s.updateZero() || !s.writeZero() || + s.segmentHeader.tryReadLock(s.segmentHeaderAddress)) { + s.incrementRead(); s.setLocalLockState(READ_LOCKED); return true; } else { @@ -74,7 +80,9 @@ public class ReadLock implements InterProcessLock { @Override public boolean tryLock(long time, @NotNull TimeUnit unit) throws InterruptedException { if (s.localLockState == UNLOCKED) { - if (s.segmentHeader.tryReadLock(s.segmentHeaderAddress, time, unit)) { + if (!s.readZero() || !s.updateZero() || !s.writeZero() || + s.segmentHeader.tryReadLock(s.segmentHeaderAddress, time, unit)) { + s.incrementRead(); s.setLocalLockState(READ_LOCKED); return true; } else { @@ -87,18 +95,7 @@ public class ReadLock implements InterProcessLock { @Override public void unlock() { - switch (s.localLockState) { - case UNLOCKED: - return; - case READ_LOCKED: - s.segmentHeader.readUnlock(s.segmentHeaderAddress); - break; - case UPDATE_LOCKED: - s.segmentHeader.updateUnlock(s.segmentHeaderAddress); - break; - case WRITE_LOCKED: - s.segmentHeader.writeUnlock(s.segmentHeaderAddress); - } + s.readUnlockAndDecrementCount(); s.setLocalLockState(UNLOCKED); // TODO what should close here? hlp.closeHashLookupPos(); diff --git a/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/SegmentStages.java b/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/SegmentStages.java index b984320f5..1c555b5d6 100644 --- a/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/SegmentStages.java +++ b/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/SegmentStages.java @@ -51,9 +51,13 @@ public abstract class SegmentStages implements InterProcessReadWriteUpdateLock { } + // "SegHeader" because stage-generator doesn't support stage names - one is a prefix of another + // there is a stage named "Segment" @Stage("SegHeader") long segmentHeaderAddress; @Stage("SegHeader") SegmentHeader segmentHeader = null; + abstract boolean segHeaderInit(); + private void initSegHeader() { segmentHeaderAddress = hh.h().ms.address() + hh.h().segmentHeaderOffset(segmentIndex); segmentHeader = BigSegmentHeader.INSTANCE; @@ -104,8 +108,7 @@ public abstract class SegmentStages implements InterProcessReadWriteUpdateLock { @Stage("Locks") public void incrementModCount() { - contextModCount = rootContextOnThisSegment.latestSameThreadSegmentModCount = - rootContextOnThisSegment.latestSameThreadSegmentModCount + 1; + contextModCount = ++rootContextOnThisSegment.latestSameThreadSegmentModCount; } // chain @@ -116,6 +119,51 @@ public abstract class SegmentStages implements InterProcessReadWriteUpdateLock { @Stage("Locks") int totalUpdateLockCount; @Stage("Locks") int totalWriteLockCount; + @Stage("Locks") + public boolean readZero() { + return rootContextOnThisSegment.totalReadLockCount == 0; + } + + @Stage("Locks") + public boolean updateZero() { + return rootContextOnThisSegment.totalUpdateLockCount == 0; + } + + @Stage("Locks") + public boolean writeZero() { + return rootContextOnThisSegment.totalWriteLockCount == 0; + } + + @Stage("Locks") + public int decrementRead() { + return rootContextOnThisSegment.totalReadLockCount -= 1; + } + + @Stage("Locks") + public int decrementUpdate() { + return rootContextOnThisSegment.totalUpdateLockCount -= 1; + } + + @Stage("Locks") + public int decrementWrite() { + return rootContextOnThisSegment.totalWriteLockCount -= 1; + } + + @Stage("Locks") + public void incrementRead() { + rootContextOnThisSegment.totalReadLockCount += 1; + } + + @Stage("Locks") + public void incrementUpdate() { + rootContextOnThisSegment.totalUpdateLockCount += 1; + } + + @Stage("Locks") + public void incrementWrite() { + rootContextOnThisSegment.totalWriteLockCount += 1; + } + public abstract boolean locksInit(); void initLocks() { @@ -131,27 +179,34 @@ public abstract class SegmentStages implements InterProcessReadWriteUpdateLock { } rootContextOnThisSegment = this; concurrentSameThreadContexts = false; + latestSameThreadSegmentModCount = 0; contextModCount = 0; - nextNode = null; + totalReadLockCount = 0; totalUpdateLockCount = 0; totalWriteLockCount = 0; } + @Stage("Locks") boolean tryFindInitLocksOfThisSegment(Object thisContext, int index) { SegmentStages c = chaining.contextAtIndexInChain(index); - if (c.segmentHeader != null && c.segmentHeaderAddress == segmentHeaderAddress && - c.rootContextOnThisSegment != null) { - //TODO implement nested contexts. Hardest part - bodies of Read/Update/WriteLock classes - throw new IllegalStateException("Nested context not implemented yet"); + if (c.segHeaderInit() && + c.segmentHeaderAddress == segmentHeaderAddress && + c.locksInit()) { + SegmentStages root = c.rootContextOnThisSegment; + this.rootContextOnThisSegment = root; + root.concurrentSameThreadContexts = true; + this.concurrentSameThreadContexts = true; + this.contextModCount = root.latestSameThreadSegmentModCount; + linkToSegmentContextsChain(); + return true; } else { return false; } } void closeLocks() { - // TODO should throw ISE on attempt to close root context when children not closed if (rootContextOnThisSegment == this) { closeRootLocks(); } else { @@ -164,71 +219,87 @@ public abstract class SegmentStages implements InterProcessReadWriteUpdateLock { @Stage("Locks") private void closeNestedLocks() { unlinkFromSegmentContextsChain(); - + readUnlockAndDecrementCount(); + } + + @Stage("Locks") + public void readUnlockAndDecrementCount() { switch (localLockState) { case UNLOCKED: - break; + return; case READ_LOCKED: - int newTotalReadLockCount = this.rootContextOnThisSegment.totalReadLockCount -= 1; + int newTotalReadLockCount = decrementRead(); if (newTotalReadLockCount == 0) { - if (this.rootContextOnThisSegment.totalUpdateLockCount == 0 && - this.rootContextOnThisSegment.totalWriteLockCount == 0) { + if (updateZero() && writeZero()) segmentHeader.readUnlock(segmentHeaderAddress); - } - } else if (newTotalReadLockCount < 0) { - throw new IllegalStateException("read underflow"); + } else { + assert newTotalReadLockCount > 0 : "read underflow"; } - break; + return; case UPDATE_LOCKED: - int newTotalUpdateLockCount = - this.rootContextOnThisSegment.totalUpdateLockCount -= 1; + int newTotalUpdateLockCount = decrementUpdate(); if (newTotalUpdateLockCount == 0) { - if (this.rootContextOnThisSegment.totalWriteLockCount == 0) { - if (this.rootContextOnThisSegment.totalReadLockCount == 0) { + if (writeZero()) { + if (readZero()) { segmentHeader.updateUnlock(segmentHeaderAddress); } else { segmentHeader.downgradeUpdateToReadLock(segmentHeaderAddress); } } - } else if (newTotalUpdateLockCount < 0) { - throw new IllegalStateException("update underflow"); + } else { + assert newTotalUpdateLockCount > 0 : "update underflow"; } - break; + return; case WRITE_LOCKED: - int newTotalWriteLockCount = this.rootContextOnThisSegment.totalWriteLockCount -= 1; + int newTotalWriteLockCount = decrementWrite(); if (newTotalWriteLockCount == 0) { - if (this.rootContextOnThisSegment.totalUpdateLockCount > 0) { + if (!updateZero()) { segmentHeader.downgradeWriteToUpdateLock(segmentHeaderAddress); } else { - if (this.rootContextOnThisSegment.totalReadLockCount > 0) { + if (!readZero()) { segmentHeader.downgradeWriteToReadLock(segmentHeaderAddress); } else { segmentHeader.writeUnlock(segmentHeaderAddress); } } + } else { + assert newTotalWriteLockCount > 0 : "write underflow"; } - break; } } + @Stage("Locks") + private void linkToSegmentContextsChain() { + SegmentStages innermostContextOnThisSegment = rootContextOnThisSegment; + while (innermostContextOnThisSegment.nextNode != null) + innermostContextOnThisSegment = innermostContextOnThisSegment.nextNode; + innermostContextOnThisSegment.nextNode = this; + } + @Stage("Locks") private void unlinkFromSegmentContextsChain() { - SegmentStages prevContext = this.rootContextOnThisSegment; + SegmentStages prevContext = rootContextOnThisSegment; while (true) { assert prevContext.nextNode != null; if (prevContext.nextNode == this) break; prevContext = prevContext.nextNode; } - assert nextNode == null; + // i. e. structured unlocking + verifyInnermostContext(); prevContext.nextNode = null; } + @Stage("Locks") + private void verifyInnermostContext() { + if (nextNode != null) + throw new IllegalStateException("Attempt to close contexts not structurally"); + } + @Stage("Locks") private void closeRootLocks() { - assert nextNode == null; - - + verifyInnermostContext(); + switch (localLockState) { case UNLOCKED: return; diff --git a/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/UpdateLock.java b/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/UpdateLock.java index 67cd5edfd..70cd27910 100644 --- a/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/UpdateLock.java +++ b/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/UpdateLock.java @@ -42,7 +42,12 @@ public class UpdateLock implements InterProcessLock { public void lock() { switch (s.localLockState) { case UNLOCKED: - s.segmentHeader.updateLock(s.segmentHeaderAddress); + if (s.updateZero() && s.writeZero()) { + if (!s.readZero()) + throw forbiddenUpdateLockWhenOuterContextReadLocked(); + s.segmentHeader.updateLock(s.segmentHeaderAddress); + } + s.incrementUpdate(); s.setLocalLockState(UPDATE_LOCKED); return; case READ_LOCKED: @@ -61,11 +66,26 @@ public class UpdateLock implements InterProcessLock { return new IllegalMonitorStateException("Cannot upgrade from read to update lock"); } + /** + * Non-static because after compilation it becomes inner class which forbids static methods + */ + @NotNull + private IllegalStateException forbiddenUpdateLockWhenOuterContextReadLocked() { + return new IllegalStateException("Cannot acquire update lock, because outer context " + + "holds read lock. In this case you should acquire update lock in the outer " + + "context up front"); + } + @Override public void lockInterruptibly() throws InterruptedException { switch (s.localLockState) { case UNLOCKED: - s.segmentHeader.updateLockInterruptibly(s.segmentHeaderAddress); + if (s.updateZero() && s.writeZero()) { + if (!s.readZero()) + throw forbiddenUpdateLockWhenOuterContextReadLocked(); + s.segmentHeader.updateLockInterruptibly(s.segmentHeaderAddress); + } + s.incrementUpdate(); s.setLocalLockState(UPDATE_LOCKED); return; case READ_LOCKED: @@ -80,11 +100,20 @@ public class UpdateLock implements InterProcessLock { public boolean tryLock() { switch (s.localLockState) { case UNLOCKED: - if (s.segmentHeader.tryUpdateLock(s.segmentHeaderAddress)) { + if (s.updateZero() && s.writeZero()) { + if (!s.readZero()) + throw forbiddenUpdateLockWhenOuterContextReadLocked(); + if (s.segmentHeader.tryUpdateLock(s.segmentHeaderAddress)) { + s.incrementUpdate(); + s.setLocalLockState(UPDATE_LOCKED); + return true; + } else { + return false; + } + } else { + s.incrementUpdate(); s.setLocalLockState(UPDATE_LOCKED); return true; - } else { - return false; } case READ_LOCKED: throw forbiddenUpgrade(); @@ -99,11 +128,20 @@ public class UpdateLock implements InterProcessLock { public boolean tryLock(long time, @NotNull TimeUnit unit) throws InterruptedException { switch (s.localLockState) { case UNLOCKED: - if (s.segmentHeader.tryUpdateLock(s.segmentHeaderAddress, time, unit)) { + if (s.updateZero() && s.writeZero()) { + if (!s.readZero()) + throw forbiddenUpdateLockWhenOuterContextReadLocked(); + if (s.segmentHeader.tryUpdateLock(s.segmentHeaderAddress, time, unit)) { + s.incrementUpdate(); + s.setLocalLockState(UPDATE_LOCKED); + return true; + } else { + return false; + } + } else { + s.incrementUpdate(); s.setLocalLockState(UPDATE_LOCKED); return true; - } else { - return false; } case READ_LOCKED: throw forbiddenUpgrade(); @@ -121,11 +159,27 @@ public class UpdateLock implements InterProcessLock { case READ_LOCKED: return; case UPDATE_LOCKED: - s.segmentHeader.downgradeUpdateToReadLock(s.segmentHeaderAddress); + int newTotalUpdateLockCount = s.decrementUpdate(); + if (newTotalUpdateLockCount == 0) { + if (s.writeZero()) + s.segmentHeader.downgradeUpdateToReadLock(s.segmentHeaderAddress); + } else { + assert newTotalUpdateLockCount > 0 : "update underflow"; + } break; case WRITE_LOCKED: - s.segmentHeader.downgradeWriteToReadLock(s.segmentHeaderAddress); + int newTotalWriteLockCount = s.decrementWrite(); + if (newTotalWriteLockCount == 0) { + if (!s.updateZero()) { + s.segmentHeader.downgradeWriteToUpdateLock(s.segmentHeaderAddress); + } else { + s.segmentHeader.downgradeWriteToReadLock(s.segmentHeaderAddress); + } + } else { + assert newTotalWriteLockCount > 0 : "write underflow"; + } } + s.incrementRead(); s.setLocalLockState(READ_LOCKED); } } diff --git a/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/WriteLock.java b/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/WriteLock.java index b10e9f554..26dbfefdc 100644 --- a/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/WriteLock.java +++ b/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/WriteLock.java @@ -42,13 +42,27 @@ public class WriteLock implements InterProcessLock { public void lock() { switch (s.localLockState) { case UNLOCKED: - s.segmentHeader.writeLock(s.segmentHeaderAddress); + if (s.writeZero()) { + if (!s.updateZero()) { + s.segmentHeader.upgradeUpdateToWriteLock(s.segmentHeaderAddress); + } else { + if (!s.readZero()) + throw forbiddenWriteLockWhenOuterContextReadLocked(); + s.segmentHeader.writeLock(s.segmentHeaderAddress); + } + } + s.incrementWrite(); s.setLocalLockState(WRITE_LOCKED); return; case READ_LOCKED: throw forbiddenUpgrade(); case UPDATE_LOCKED: - s.segmentHeader.upgradeUpdateToWriteLock(s.segmentHeaderAddress); + if (s.writeZero()) { + assert !s.updateZero(); + s.segmentHeader.upgradeUpdateToWriteLock(s.segmentHeaderAddress); + } + s.decrementUpdate(); + s.incrementWrite(); s.setLocalLockState(WRITE_LOCKED); case WRITE_LOCKED: // do nothing @@ -63,17 +77,42 @@ public class WriteLock implements InterProcessLock { return new IllegalMonitorStateException("Cannot upgrade from read to write lock"); } + /** + * Non-static because after compilation it becomes inner class which forbids static methods + */ + @NotNull + private IllegalStateException forbiddenWriteLockWhenOuterContextReadLocked() { + return new IllegalStateException("Cannot acquire write lock, because outer context " + + "holds read lock. In this case you should acquire update lock in the outer " + + "context up front"); + } + @Override public void lockInterruptibly() throws InterruptedException { switch (s.localLockState) { case UNLOCKED: - s.segmentHeader.writeLockInterruptibly(s.segmentHeaderAddress); + if (s.writeZero()) { + if (!s.updateZero()) { + s.segmentHeader.upgradeUpdateToWriteLockInterruptibly( + s.segmentHeaderAddress); + } else { + if (!s.readZero()) + throw forbiddenWriteLockWhenOuterContextReadLocked(); + s.segmentHeader.writeLockInterruptibly(s.segmentHeaderAddress); + } + } + s.incrementWrite(); s.setLocalLockState(WRITE_LOCKED); return; case READ_LOCKED: throw forbiddenUpgrade(); case UPDATE_LOCKED: - s.segmentHeader.upgradeUpdateToWriteLockInterruptibly(s.segmentHeaderAddress); + if (s.writeZero()) { + assert !s.updateZero(); + s.segmentHeader.upgradeUpdateToWriteLockInterruptibly(s.segmentHeaderAddress); + } + s.decrementUpdate(); + s.incrementWrite(); s.setLocalLockState(WRITE_LOCKED); case WRITE_LOCKED: // do nothing @@ -84,20 +123,49 @@ public class WriteLock implements InterProcessLock { public boolean tryLock() { switch (s.localLockState) { case UNLOCKED: - if (s.segmentHeader.tryWriteLock(s.segmentHeaderAddress)) { + if (s.writeZero()) { + if (!s.updateZero()) { + if (s.segmentHeader.tryUpgradeUpdateToWriteLock(s.segmentHeaderAddress)) { + s.incrementWrite(); + s.setLocalLockState(WRITE_LOCKED); + return true; + } else { + return false; + } + } else { + if (!s.readZero()) + throw forbiddenWriteLockWhenOuterContextReadLocked(); + if (s.segmentHeader.tryWriteLock(s.segmentHeaderAddress)) { + s.incrementWrite(); + s.setLocalLockState(WRITE_LOCKED); + return true; + } else { + return false; + } + } + } else { + s.incrementWrite(); s.setLocalLockState(WRITE_LOCKED); return true; - } else { - return false; } case READ_LOCKED: throw forbiddenUpgrade(); case UPDATE_LOCKED: - if (s.segmentHeader.tryUpgradeUpdateToWriteLock(s.segmentHeaderAddress)) { + if (s.writeZero()) { + assert !s.updateZero(); + if (s.segmentHeader.tryUpgradeUpdateToWriteLock(s.segmentHeaderAddress)) { + s.decrementUpdate(); + s.incrementWrite(); + s.setLocalLockState(WRITE_LOCKED); + return true; + } else { + return false; + } + } else { + s.decrementUpdate(); + s.incrementWrite(); s.setLocalLockState(WRITE_LOCKED); return true; - } else { - return false; } case WRITE_LOCKED: return true; @@ -109,21 +177,51 @@ public class WriteLock implements InterProcessLock { public boolean tryLock(long time, @NotNull TimeUnit unit) throws InterruptedException { switch (s.localLockState) { case UNLOCKED: - if (s.segmentHeader.tryWriteLock(s.segmentHeaderAddress, time, unit)) { + if (s.writeZero()) { + if (!s.updateZero()) { + if (s.segmentHeader.tryUpgradeUpdateToWriteLock( + s.segmentHeaderAddress, time, unit)) { + s.incrementWrite(); + s.setLocalLockState(WRITE_LOCKED); + return true; + } else { + return false; + } + } else { + if (!s.readZero()) + throw forbiddenWriteLockWhenOuterContextReadLocked(); + if (s.segmentHeader.tryWriteLock(s.segmentHeaderAddress, time, unit)) { + s.incrementWrite(); + s.setLocalLockState(WRITE_LOCKED); + return true; + } else { + return false; + } + } + } else { + s.incrementWrite(); s.setLocalLockState(WRITE_LOCKED); return true; - } else { - return false; } case READ_LOCKED: throw forbiddenUpgrade(); case UPDATE_LOCKED: - if (s.segmentHeader.tryUpgradeUpdateToWriteLock( - s.segmentHeaderAddress, time, unit)) { + if (s.writeZero()) { + assert !s.updateZero(); + if (s.segmentHeader.tryUpgradeUpdateToWriteLock( + s.segmentHeaderAddress, time, unit)) { + s.decrementUpdate(); + s.incrementWrite(); + s.setLocalLockState(WRITE_LOCKED); + return true; + } else { + return false; + } + } else { + s.decrementUpdate(); + s.incrementWrite(); s.setLocalLockState(WRITE_LOCKED); return true; - } else { - return false; } case WRITE_LOCKED: return true; @@ -139,8 +237,14 @@ public class WriteLock implements InterProcessLock { case UPDATE_LOCKED: return; case WRITE_LOCKED: - s.segmentHeader.downgradeWriteToUpdateLock(s.segmentHeaderAddress); + int newTotalWriteLockCount = s.decrementWrite(); + if (newTotalWriteLockCount == 0) { + s.segmentHeader.downgradeWriteToUpdateLock(s.segmentHeaderAddress); + } else { + assert newTotalWriteLockCount > 0 : "write underflow"; + } } + s.incrementUpdate(); s.setLocalLockState(UPDATE_LOCKED); } } diff --git a/src/test/java/net/openhft/chronicle/map/NestedContextsTest.java b/src/test/java/net/openhft/chronicle/map/NestedContextsTest.java new file mode 100644 index 000000000..dc52d5420 --- /dev/null +++ b/src/test/java/net/openhft/chronicle/map/NestedContextsTest.java @@ -0,0 +1,181 @@ +/* + * Copyright 2015 Higher Frequency Trading + * + * http://www.higherfrequencytrading.com + * + * Licensed 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 net.openhft.chronicle.map; + +import com.google.common.collect.ImmutableSet; +import org.jetbrains.annotations.NotNull; +import org.junit.Test; + +import java.util.HashSet; +import java.util.Set; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.ForkJoinPool; +import java.util.concurrent.ThreadLocalRandom; + +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertTrue; + +public class NestedContextsTest { + + @Test + public void nestedContextsTest() throws ExecutionException, InterruptedException { + ChronicleMap> graph = ChronicleMapBuilder + .of(Integer.class, (Class>) (Class) Set.class) + .actualSegments(1) + .create(); + + addEdge(graph, 1, 2); + addEdge(graph, 2, 3); + addEdge(graph, 1, 3); + + assertEquals(ImmutableSet.of(2, 3), graph.get(1)); + assertEquals(ImmutableSet.of(1, 3), graph.get(2)); + assertEquals(ImmutableSet.of(1, 2), graph.get(3)); + + verifyGraphConsistent(graph); + + ForkJoinPool pool = new ForkJoinPool(8); + try { + pool.submit(() -> { + ThreadLocalRandom.current().ints().limit(10_000).parallel().forEach(i -> { + int sourceNode = Math.abs(i % 10); + int targetNode; + do { + targetNode = ThreadLocalRandom.current().nextInt(10); + } while (targetNode == sourceNode); + if (i % 2 == 0) { + addEdge(graph, sourceNode, targetNode); + } else { + removeEdge(graph, sourceNode, targetNode); + } + }); + }).get(); + verifyGraphConsistent(graph); + } finally { + pool.shutdownNow(); + } + } + + private static void verifyGraphConsistent(ChronicleMap> graph) { + graph.forEach((node, neighbours) -> + neighbours.forEach(neighbour -> assertTrue(graph.get(neighbour).contains(node)))); + } + + public static boolean addEdge( + ChronicleMap> graph, int source, int target) { + if (source == target) + throw new IllegalArgumentException("loops are forbidden"); + + try (ExternalMapQueryContext, ?> sc = graph.queryContext(source)) { + sc.updateLock().lock(); + try (ExternalMapQueryContext, ?> tc = + graph.queryContext(target)) { + tc.updateLock().lock(); + MapEntry> sEntry = sc.entry(); + if (sEntry != null) { + MapEntry> tEntry = tc.entry(); + if (tEntry != null) { + return addEdgeBothPresent(sc, sEntry, source, tc, tEntry, target); + } else { + addEdgePresentAbsent(sc, sEntry, source, tc, target); + return true; + } + } else { + MapEntry> tEntry = tc.entry(); + if (tEntry != null) { + addEdgePresentAbsent(tc, tEntry, target, sc, source); + } else { + addEdgeBothAbsent(sc, source, tc, target); + } + return true; + } + } + } + } + + private static boolean addEdgeBothPresent( + MapQueryContext, ?> sc, + @NotNull MapEntry> sEntry, int source, + MapQueryContext, ?> tc, + @NotNull MapEntry> tEntry, int target) { + Set sNeighbours = sEntry.value().get(); + if (sNeighbours.add(target)) { + Set tNeighbours = tEntry.value().get(); + boolean added = tNeighbours.add(source); + assert added; + sEntry.doReplaceValue(sc.wrapValueAsData(sNeighbours)); + tEntry.doReplaceValue(tc.wrapValueAsData(tNeighbours)); + return true; + } else { + return false; + } + } + + private static void addEdgePresentAbsent( + MapQueryContext, ?> sc, + @NotNull MapEntry> sEntry, int source, + MapQueryContext, ?> tc, int target) { + Set sNeighbours = sEntry.value().get(); + boolean added = sNeighbours.add(target); + assert added; + sEntry.doReplaceValue(sc.wrapValueAsData(sNeighbours)); + + addEdgeOneSide(tc, source); + } + + private static void addEdgeBothAbsent(MapQueryContext, ?> sc, int source, + MapQueryContext, ?> tc, int target) { + addEdgeOneSide(sc, target); + addEdgeOneSide(tc, source); + } + + private static void addEdgeOneSide(MapQueryContext, ?> tc, int source) { + Set tNeighbours = new HashSet<>(); + tNeighbours.add(source); + MapAbsentEntry> tAbsentEntry = tc.absentEntry(); + assert tAbsentEntry != null; + tAbsentEntry.doInsert(tc.wrapValueAsData(tNeighbours)); + } + + public static boolean removeEdge( + ChronicleMap> graph, int source, int target) { + try (ExternalMapQueryContext, ?> sc = graph.queryContext(source)) { + sc.updateLock().lock(); + MapEntry> sEntry = sc.entry(); + if (sEntry == null) + return false; + Set sNeighbours = sEntry.value().get(); + if (!sNeighbours.remove(target)) + return false; + try (ExternalMapQueryContext, ?> tc = + graph.queryContext(target)) { + tc.updateLock().lock(); + MapEntry> tEntry = tc.entry(); + if (tEntry == null) + throw new IllegalStateException("target node should be present in the graph"); + Set tNeighbours = tEntry.value().get(); + if (!tNeighbours.remove(source)) + throw new IllegalStateException("the target node have an edge to the source"); + sEntry.doReplaceValue(sc.wrapValueAsData(sNeighbours)); + tEntry.doReplaceValue(tc.wrapValueAsData(tNeighbours)); + return true; + } + } + } +}