ConcurrentBag.cs :  » 2.6.4-mono-.net-core » System.Collections » System » Collections » Concurrent » C# / CSharp Open Source

// 
// ConcurrentBag.cs
//  
// Author:
//       Jrmie "Garuma" Laval <jeremie.laval@gmail.com>
// 
// Copyright (c) 2009 Jrmie "Garuma" Laval
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#if NET_4_0
using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Runtime.InteropServices;

using System.Threading;
using System.Threading.Tasks;

namespace System.Collections.Concurrent{
  [ComVisible (false)]
  [DebuggerDisplay ("Count={Count}")]
  [DebuggerTypeProxy (typeof (CollectionDebuggerView<>))]
  public class ConcurrentBag<T> : IProducerConsumerCollection<T>, IEnumerable<T>, IEnumerable
  {
    const int multiplier = 2;
    int size = Environment.ProcessorCount + 1;
    int count;
    
    CyclicDeque<T>[] container;
    
    object syncLock = new object ();
    
    public ConcurrentBag ()
    {
      container = new CyclicDeque<T>[size];
      for (int i = 0; i < container.Length; i++)
        container[i] = new CyclicDeque<T> ();
    }
    
    public ConcurrentBag (IEnumerable<T> enumerable) : this ()
    {
      foreach (T item in enumerable)
        Add (item);
    }
    
    public bool TryAdd (T item)
    {
      Add (item);
      
      return true;
    }
    
    public void Add (T item)
    {
      Interlocked.Increment (ref count);
      GrowIfNecessary ();
      
      CyclicDeque<T> bag = GetBag ();
      bag.PushBottom (item);
    }
    
    public bool TryTake (out T item)
    {
      item = default (T);
      CyclicDeque<T> bag = GetBag ();
      
      if (bag == null || bag.PopBottom (out item) != PopResult.Succeed) {
        for (int i = 0; i < container.Length; i++) {
          if (container[i].PopTop (out item) == PopResult.Succeed) {
            Interlocked.Decrement (ref count);
            return true;
          }
        }
      } else {
        Interlocked.Decrement (ref count);
        return true;
      }
      
      return false;
    }
    
    public int Count {
      get {
        return count;
      }
    }
    
    public bool IsEmpty {
      get {
        return count == 0;
      }
    }
    
    object System.Collections.ICollection.SyncRoot  {
      get {
        return this;
      }
    }
    
    bool System.Collections.ICollection.IsSynchronized  {
      get {
        return true;
      }
    }
    
    IEnumerator IEnumerable.GetEnumerator ()
    {
      return GetEnumeratorInternal ();
    }
    
    IEnumerator<T> IEnumerable<T>.GetEnumerator ()
    {
      return GetEnumeratorInternal ();
    }
    
    IEnumerator<T> GetEnumeratorInternal ()
    {
      for (int i = 0; i < size; i++) {
        CyclicDeque<T> bag = container[i];
        foreach (T item in bag.GetEnumerable ()) {
          yield return item;
        }
      }
    }
    
    void System.Collections.ICollection.CopyTo (Array array, int index)
    {
      T[] a = array as T[];
      if (a == null)
        return;
      
      CopyTo (a, index);
    }
    
    public void CopyTo (T[] array, int index)
    {
      int c = count;
      if (array.Length < c + index)
        throw new InvalidOperationException ("Array is not big enough");
      
      CopyTo (array, index, c);
    }
    
    void CopyTo (T[] array, int index, int num)
    {
      int i = index;
      
      foreach (T item in this) {
        if (i >= num)
          break;
        
        array[i++] = item;
      }
    }
    
    public T[] ToArray ()
    {
      int c = count;
      T[] temp = new T[c];
      
      CopyTo (temp, 0, c);
      
      return temp;
    }
      
    int GetIndex ()
    {
      return Thread.CurrentThread.ManagedThreadId - 1;
    }
    
    void GrowIfNecessary ()
    {
      int index = GetIndex ();
      int currentSize = size;
      
      while (index > currentSize - 1) {
        currentSize = size;
        Grow (currentSize);
      }
    }
    
    CyclicDeque<T> GetBag ()
    {      
      int i = GetIndex ();
      
      return i < container.Length ? container[i] : null;
    }
    
    void Grow (int referenceSize)
    {
      lock (syncLock) {
        if (referenceSize != size)
          return;
        
        CyclicDeque<T>[] slice = new CyclicDeque<T>[size * multiplier];
        int i = 0;
        for (i = 0; i < container.Length; i++)
          slice[i] = container[i];
        for (; i < slice.Length; i++)
          slice[i] = new CyclicDeque<T> ();
        
        container = slice;
        size = slice.Length;
      }
    }
  }
}
#endif