private void CalculateThresholds(long maximumBufferSize, TargetUtilizationLevels levels)
{
switch (levels)
{
case TargetUtilizationLevels.Low:
m_levelNone = (long)(0.1 * maximumBufferSize);
m_levelLow = (long)(0.25 * maximumBufferSize);
m_levelNormal = (long)(0.50 * maximumBufferSize);
m_levelHigh = (long)(0.75 * maximumBufferSize);
m_levelVeryHigh = (long)(0.90 * maximumBufferSize);
break;
case TargetUtilizationLevels.Medium:
m_levelNone = (long)(0.25 * maximumBufferSize);
m_levelLow = (long)(0.50 * maximumBufferSize);
m_levelNormal = (long)(0.75 * maximumBufferSize);
m_levelHigh = (long)(0.85 * maximumBufferSize);
m_levelVeryHigh = (long)(0.95 * maximumBufferSize);
break;
case TargetUtilizationLevels.High:
m_levelNone = (long)(0.5 * maximumBufferSize);
m_levelLow = (long)(0.75 * maximumBufferSize);
m_levelNormal = (long)(0.85 * maximumBufferSize);
m_levelHigh = (long)(0.95 * maximumBufferSize);
m_levelVeryHigh = (long)(0.97 * maximumBufferSize);
break;
default:
throw new ArgumentOutOfRangeException("levels");
}
}
/// <summary>
/// Changes the utilization level
/// </summary>
/// <param name="utilizationLevel"></param>
/// <returns></returns>
public void SetTargetUtilizationLevel(TargetUtilizationLevels utilizationLevel)
{
lock (m_syncRoot)
{
if (m_disposed)
{
throw new ObjectDisposedException(GetType().FullName);
}
TargetUtilizationLevel = utilizationLevel;
CalculateThresholds(MaximumPoolSize, utilizationLevel);
}
}
/// <summary>
/// Creates a new <see cref="MemoryPool"/>.
/// </summary>
/// <param name="pageSize">The desired page size. Must be between 4KB and 256KB</param>
/// <param name="maximumBufferSize">The desired maximum size of the allocation. Note: could be less if there is not enough system memory.</param>
/// <param name="utilizationLevel">Specifies the desired utilization level of the allocated space.</param>
public MemoryPool(int pageSize = 64 * 1024, long maximumBufferSize = -1, TargetUtilizationLevels utilizationLevel = TargetUtilizationLevels.Low)
{
if (pageSize < 4096 || pageSize > 256 * 1024)
{
throw new ArgumentOutOfRangeException("pageSize", "Page size must be between 4KB and 256KB and a power of 2");
}
if (!BitMath.IsPowerOfTwo((uint)pageSize))
{
throw new ArgumentOutOfRangeException("pageSize", "Page size must be between 4KB and 256KB and a power of 2");
}
m_syncRoot = new object();
m_syncAllocate = new object();
PageSize = pageSize;
PageMask = PageSize - 1;
PageShiftBits = BitMath.CountBitsSet((uint)PageMask);
m_pageList = new MemoryPoolPageList(PageSize, maximumBufferSize);
m_requestCollectionEvent = new ThreadSafeList <WeakEventHandler <CollectionEventArgs> >();
SetTargetUtilizationLevel(utilizationLevel);
}
private void CalculateThresholds(long maximumBufferSize, TargetUtilizationLevels levels)
{
switch (levels)
{
case TargetUtilizationLevels.Low:
m_levelNone = (long)(0.1 * maximumBufferSize);
m_levelLow = (long)(0.25 * maximumBufferSize);
m_levelNormal = (long)(0.50 * maximumBufferSize);
m_levelHigh = (long)(0.75 * maximumBufferSize);
m_levelVeryHigh = (long)(0.90 * maximumBufferSize);
break;
case TargetUtilizationLevels.Medium:
m_levelNone = (long)(0.25 * maximumBufferSize);
m_levelLow = (long)(0.50 * maximumBufferSize);
m_levelNormal = (long)(0.75 * maximumBufferSize);
m_levelHigh = (long)(0.85 * maximumBufferSize);
m_levelVeryHigh = (long)(0.95 * maximumBufferSize);
break;
case TargetUtilizationLevels.High:
m_levelNone = (long)(0.5 * maximumBufferSize);
m_levelLow = (long)(0.75 * maximumBufferSize);
m_levelNormal = (long)(0.85 * maximumBufferSize);
m_levelHigh = (long)(0.95 * maximumBufferSize);
m_levelVeryHigh = (long)(0.97 * maximumBufferSize);
break;
default:
throw new ArgumentOutOfRangeException("levels");
}
}
/// <summary>
/// Changes the utilization level
/// </summary>
/// <param name="utilizationLevel"></param>
/// <returns></returns>
public void SetTargetUtilizationLevel(TargetUtilizationLevels utilizationLevel)
{
lock (m_syncRoot)
{
if (m_disposed)
throw new ObjectDisposedException(GetType().FullName);
TargetUtilizationLevel = utilizationLevel;
CalculateThresholds(MaximumPoolSize, utilizationLevel);
}
}
/// <summary>
/// Creates a new <see cref="MemoryPool"/>.
/// </summary>
/// <param name="pageSize">The desired page size. Must be between 4KB and 256KB</param>
/// <param name="maximumBufferSize">The desired maximum size of the allocation. Note: could be less if there is not enough system memory.</param>
/// <param name="utilizationLevel">Specifies the desired utilization level of the allocated space.</param>
public MemoryPool(int pageSize = 64 * 1024, long maximumBufferSize = -1, TargetUtilizationLevels utilizationLevel = TargetUtilizationLevels.Low)
{
if (pageSize < 4096 || pageSize > 256 * 1024)
throw new ArgumentOutOfRangeException("pageSize", "Page size must be between 4KB and 256KB and a power of 2");
if (!BitMath.IsPowerOfTwo((uint)pageSize))
throw new ArgumentOutOfRangeException("pageSize", "Page size must be between 4KB and 256KB and a power of 2");
m_syncRoot = new object();
m_syncAllocate = new object();
PageSize = pageSize;
PageMask = PageSize - 1;
PageShiftBits = BitMath.CountBitsSet((uint)PageMask);
m_pageList = new MemoryPoolPageList(PageSize, maximumBufferSize);
m_requestCollectionEvent = new ThreadSafeList<WeakEventHandler<CollectionEventArgs>>();
SetTargetUtilizationLevel(utilizationLevel);
}
