| /* |
| * Copyright 2000-2010 JetBrains s.r.o. |
| * |
| * 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 com.intellij.util.containers; |
| |
| import org.jetbrains.annotations.NotNull; |
| |
| import java.lang.reflect.Array; |
| |
| /** |
| * User: cdr |
| */ |
| public abstract class StripedLockHolder<T> { |
| private static final int NUM_LOCKS = 256; |
| protected final T[] ourLocks; |
| private int ourLockAllocationCounter = 0; |
| |
| @SuppressWarnings("unchecked") |
| protected StripedLockHolder(@NotNull Class<T> aClass) { |
| ourLocks = (T[])Array.newInstance(aClass, NUM_LOCKS); |
| for (int i = 0; i < ourLocks.length; i++) { |
| ourLocks[i] = create(); |
| } |
| } |
| |
| @NotNull |
| protected abstract T create(); |
| |
| @NotNull |
| public T allocateLock() { |
| return ourLocks[allocateLockIndex()]; |
| } |
| |
| public int allocateLockIndex() { |
| return ourLockAllocationCounter = (ourLockAllocationCounter + 1) % NUM_LOCKS; |
| } |
| } |