IGNITE-23301 Fix scalability issues with coarse locks

modules/core/src/main/java/org/apache/ignite/internal/util/IgniteStripedReadWriteLock.java

@@ -0,0 +1,222 @@
+/*
+ * 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.ignite.internal.util;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+/**
+ * ReadWriteLock with striping mechanics. Compared to {@link ReentrantReadWriteLock} it has slightly improved performance of
+ * {@link ReadWriteLock#readLock()} operations at the cost of {@link ReadWriteLock#writeLock()} operations and memory consumption. It also
+ * supports reentrancy semantics like {@link ReentrantReadWriteLock}.
+ */
+public class IgniteStripedReadWriteLock implements ReadWriteLock {
+    /** Index generator. */
+    private static final AtomicInteger IDX_GEN = new AtomicInteger();
+
+    /** Index. */
+    private static final ThreadLocal<Integer> IDX = ThreadLocal.withInitial(() -> IDX_GEN.incrementAndGet());
+
+    /** Locks. */
+    private final ReentrantReadWriteLock[] locks;
+
+    /** Composite write lock. */
+    private final WriteLock writeLock;
+
+    /**
+     * Creates a new instance with given concurrency level.
+     *
+     * @param concurrencyLvl Number of internal read locks.
+     */
+    public IgniteStripedReadWriteLock(int concurrencyLvl) {
+        locks = new ReentrantReadWriteLock[concurrencyLvl];
+
+        for (int i = 0; i < concurrencyLvl; i++) {
+            locks[i] = new ReentrantReadWriteLock();
+        }
+
+        writeLock = new WriteLock();
+    }
+
+    /**
+     * Gets current index.
+     *
+     * @return Index of current thread stripe.
+     */
+    private int curIdx() {
+        int idx = IDX.get();
+
+        return idx % locks.length;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public Lock readLock() {
+        return locks[curIdx()].readLock();
+    }
+
+    /**
+     * Get a lock by stripe.
+     *
+     * @param idx Stripe index.
+     * @return The lock.
+     */
+    public Lock readLock(int idx) {
+        return locks[idx].readLock();
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public Lock writeLock() {
+        return writeLock;
+    }
+
+    /**
+     * Queries if the write lock is held by the current thread.
+     *
+     * @return {@code true} if the current thread holds the write lock and {@code false} otherwise
+     */
+    public boolean isWriteLockedByCurrentThread() {
+        return locks[locks.length - 1].isWriteLockedByCurrentThread();
+    }
+
+    /**
+     * Queries the number of reentrant read holds on this lock by the current thread.  A reader thread has a hold on a lock for each lock
+     * action that is not matched by an unlock action.
+     *
+     * @return the number of holds on the read lock by the current thread, or zero if the read lock is not held by the current thread
+     */
+    public int getReadHoldCount() {
+        return locks[curIdx()].getReadHoldCount();
+    }
+
+    /**
+     * Write lock.
+     */
+    private class WriteLock implements Lock {
+        /** {@inheritDoc} */
+        @Override
+        public void lock() {
+            try {
+                lock0(false);
+            } catch (InterruptedException ignore) {
+                assert false : "Should never happen";
+            }
+        }
+
+        /** {@inheritDoc} */
+        @Override
+        public void lockInterruptibly() throws InterruptedException {
+            lock0(true);
+        }
+
+        /** {@inheritDoc} */
+        @Override
+        public void unlock() {
+            unlock0(locks.length - 1);
+        }
+
+        /**
+         * Internal lock routine.
+         *
+         * @param canInterrupt Whether to acquire the lock interruptibly.
+         * @throws InterruptedException If interrupted.
+         */
+        private void lock0(boolean canInterrupt) throws InterruptedException {
+            int i = 0;
+
+            try {
+                for (; i < locks.length; i++) {
+                    if (canInterrupt) {
+                        locks[i].writeLock().lockInterruptibly();
+                    } else {
+                        locks[i].writeLock().lock();
+                    }
+                }
+            } catch (InterruptedException e) {
+                unlock0(i - 1);
+
+                throw e;
+            }
+        }
+
+        /**
+         * Internal unlock routine.
+         *
+         * @param fromIdx Start index.
+         */
+        private void unlock0(int fromIdx) {
+            for (int i = fromIdx; i >= 0; i--) {
+                locks[i].writeLock().unlock();
+            }
+        }
+
+        /** {@inheritDoc} */
+        @Override
+        public boolean tryLock() {
+            int i = 0;
+
+            try {
+                for (; i < locks.length; i++) {
+                    if (!locks[i].writeLock().tryLock()) {
+                        break;
+                    }
+                }
+            } finally {
+                if (0 < i && i < locks.length) {
+                    unlock0(i - 1);
+                }
+            }
+
+            return i == locks.length;
+        }
+
+        /** {@inheritDoc} */
+        @Override
+        public boolean tryLock(long time, TimeUnit unit) throws InterruptedException {
+            int i = 0;
+
+            long end = unit.toNanos(time) + System.nanoTime();
+
+            try {
+                for (; i < locks.length && System.nanoTime() < end; i++) {
+                    if (!locks[i].writeLock().tryLock(time, unit)) {
+                        break;
+                    }
+                }
+            } finally {
+                if (0 < i && i < locks.length) {
+                    unlock0(i - 1);
+                }
+            }
+
+            return i == locks.length;
+        }
+
+        /** {@inheritDoc} */
+        @Override
+        public Condition newCondition() {
+            throw new UnsupportedOperationException();
+        }
+    }
+}
+