Exemplo n.º 1
0
        /// <summary>
        /// Called to return a block to the pool. Once Return has been called the memory no longer belongs to the caller, and
        /// Very Bad Things will happen if the memory is read of modified subsequently. If a caller fails to call Return and the
        /// block tracking object is garbage collected, the block tracking object's finalizer will automatically re-create and return
        /// a new tracking object into the pool. This will only happen if there is a bug in the server, however it is necessary to avoid
        /// leaving "dead zones" in the slab due to lost block tracking objects.
        /// </summary>
        /// <param name="block">The block to return. It must have been acquired by calling Lease on the same memory pool instance.</param>
        internal void Return(RioMemoryPoolBlock block)
        {
#if BLOCK_LEASE_TRACKING
            Debug.Assert(block.Pool == this, "Returned block was not leased from this pool");
            Debug.Assert(block.IsLeased, $"Block being returned to pool twice: {block.Leaser}{Environment.NewLine}");
            block.IsLeased = false;
#endif

            if (block.Slab != null && block.Slab.IsActive)
            {
                _blocks.Enqueue(block);
            }
            else
            {
                GC.SuppressFinalize(block);
            }
        }
Exemplo n.º 2
0
        /// <summary>
        /// Internal method called when a block is requested and the pool is empty. It allocates one additional slab, creates all of the
        /// block tracking objects, and adds them all to the pool.
        /// </summary>
        private RioMemoryPoolBlock AllocateSlab()
        {
            var slab = RioMemoryPoolSlab.Create(_slabLength);

            _slabs.Push(slab);

            _slabAllocationCallback?.Invoke(slab);
            slab._deallocationCallback = _slabDeallocationCallback;

            var basePtr     = slab.NativePointer;
            var firstOffset = (int)((_blockStride - 1) - ((ulong)(basePtr + _blockStride - 1) % _blockStride));

            var poolAllocationLength = _slabLength - _blockStride;

            var offset = firstOffset;

            for (;
                 offset + _blockLength < poolAllocationLength;
                 offset += _blockStride)
            {
                var block = RioMemoryPoolBlock.Create(
                    offset,
                    _blockLength,
                    this,
                    slab);
#if BLOCK_LEASE_TRACKING
                block.IsLeased = true;
#endif
                Return(block);
            }

            // return last block rather than adding to pool
            var newBlock = RioMemoryPoolBlock.Create(
                offset,
                _blockLength,
                this,
                slab);

            return(newBlock);
        }