public RpcTcpBufferPool(int capacity, Func <T> allocator)
{
//
// 所有的capacity都是2的幂
IICAssert.IsTrue(capacity < 1024 * 1024);
_capacity = NumberUtils.NextPower2(capacity);
_nodes = new CachedNode[_capacity];
_capacityMask = _capacity - 1;
_count = _capacity;
//
// 填充满所有对象
for (int i = 0; i < _capacity; i++)
{
var node = new CachedNode()
{
Value = allocator(),
Fetched = 0,
Index = i,
};
node.Value.CachedIndex = i;
_nodes[i] = node;
}
}
public void Release(T value)
{
CachedNode node = _nodes[value.CachedIndex];
//
// 实际Release掉了, 就增加可用数量
//原先FetchPrepare在CompareExchange里面，会导致node马上被另一个线程fetch使用后，却被FetchPrepare（）清了所有内容
//造成callback不能回调，依附sokcket sendpending一直增加，这个asynarg 不能会导池内
node.Value.FetchPrepare();
if (Interlocked.CompareExchange(ref node.Fetched, 0, 1) == 1)
{
Interlocked.Increment(ref _count);
}
}
public T Fetch()
{
//
// 先减小对象数，避免容器空
int count = Interlocked.Decrement(ref _count);
if (count < 0)
{
Interlocked.Increment(ref _count);
return(default(T));
}
//
// 在head后寻找第一个可用，然后获取值
int index = -1;
CachedNode node = null;
do
{
index = Interlocked.Increment(ref _head) & _capacityMask;
node = _nodes[index];
} while (Interlocked.CompareExchange(ref node.Fetched, 1, 0) != 0);
return(node.Value);
}
private CachedNode AddCachedNode(Node node)
{
CachedNode cachedNode;
if (_cacheNodes.TryGetValue(node.Id, out cachedNode))
return cachedNode; //exists
if (_cacheNodes.Count > MaxCacheNodes)
_cacheNodes.Remove(_cacheNodes.First().Key);
cachedNode = new CachedNode(node);
_cacheNodes.Add(node.Id, cachedNode);
return cachedNode;
}
