public override void Return(T[] array, bool clearArray = false)
{
if (array == null)
{
throw new ArgumentNullException(nameof(array));
}
else if (array.Length == 0)
{
// Ignore empty arrays. When a zero-length array is rented, we return a singleton
// rather than actually taking a buffer out of the lowest bucket.
return;
}
// Determine with what bucket this array length is associated
int bucket = Utilities.SelectBucketIndex(array.Length);
// If we can tell that the buffer was allocated, drop it. Otherwise, check if we have space in the pool
bool haveBucket = bucket < _buckets.Length;
if (haveBucket)
{
// Clear the array if the user requests
if (clearArray)
{
Array.Clear(array, 0, array.Length);
}
// Return the buffer to its bucket. In the future, we might consider having Return return false
// instead of dropping a bucket, in which case we could try to return to a lower-sized bucket,
// just as how in Rent we allow renting from a higher-sized bucket.
_buckets[bucket].Return(array);
}
// Log that the buffer was returned
ArrayPoolEventSource log = ArrayPoolEventSource.Log;
if (log.IsEnabled())
{
int bufferId = array.GetHashCode();
log.BufferReturned(bufferId, array.Length, Id);
if (!haveBucket)
{
log.BufferDropped(bufferId, array.Length, Id, ArrayPoolEventSource.NoBucketId, ArrayPoolEventSource.BufferDroppedReason.Full);
}
}
}
/// <summary>
/// Attempts to return the buffer to the bucket. If successful, the buffer will be stored
/// in the bucket and true will be returned; otherwise, the buffer won't be stored, and false
/// will be returned.
/// </summary>
internal void Return(T[] array)
{
// Check to see if the buffer is the correct size for this bucket
if (array.Length != _bufferLength)
{
throw new ArgumentException(SR.ArgumentException_BufferNotFromPool, nameof(array));
}
bool returned;
// While holding the spin lock, if there's room available in the bucket,
// put the buffer into the next available slot. Otherwise, we just drop it.
// The try/finally is necessary to properly handle thread aborts on platforms
// which have them.
bool lockTaken = false;
try
{
_lock.Enter(ref lockTaken);
returned = _index != 0;
if (returned)
{
_buffers[--_index] = array;
}
}
finally
{
if (lockTaken)
{
_lock.Exit(false);
}
}
if (!returned)
{
ArrayPoolEventSource log = ArrayPoolEventSource.Log;
if (log.IsEnabled())
{
log.BufferDropped(array.GetHashCode(), _bufferLength, _poolId, Id, ArrayPoolEventSource.BufferDroppedReason.Full);
}
}
}
public override void Return(T[] array, bool clearArray = false)
{
if (array == null)
{
throw new ArgumentNullException(nameof(array));
}
// Determine with what bucket this array length is associated
int bucketIndex = Utilities.SelectBucketIndex(array.Length);
// If we can tell that the buffer was allocated (or empty), drop it. Otherwise, check if we have space in the pool.
bool returned = true;
bool haveBucket = bucketIndex < _buckets.Length;
if (haveBucket)
{
// Clear the array if the user requests.
if (clearArray)
{
Array.Clear(array, 0, array.Length);
}
// Check to see if the buffer is the correct size for this bucket
if (array.Length != _bucketArraySizes[bucketIndex])
{
throw new ArgumentException(SR.ArgumentException_BufferNotFromPool, nameof(array));
}
// Write through the TLS bucket. If there weren't any buckets, create them
// and store this array into it. If there were, store this into it, and
// if there was a previous one there, push that to the global stack. This
// helps to keep LIFO access such that the most recently pushed stack will
// be in TLS and the first to be popped next.
T[]?[]? tlsBuckets = t_tlsBuckets;
if (tlsBuckets == null)
{
t_tlsBuckets = tlsBuckets = new T[NumBuckets][];
tlsBuckets[bucketIndex] = array;
if (s_trimBuffers)
{
Debug.Assert(s_allTlsBuckets != null, "Should be non-null iff s_trimBuffers is true");
s_allTlsBuckets.Add(tlsBuckets, null);
if (Interlocked.Exchange(ref _callbackCreated, 1) != 1)
{
Gen2GcCallback.Register(Gen2GcCallbackFunc, this);
}
}
}
else
{
T[]? prev = tlsBuckets[bucketIndex];
tlsBuckets[bucketIndex] = array;
if (prev != null)
{
PerCoreLockedStacks stackBucket = _buckets[bucketIndex] ?? CreatePerCoreLockedStacks(bucketIndex);
returned = stackBucket.TryPush(prev);
}
}
}
// Log that the buffer was returned
ArrayPoolEventSource log = ArrayPoolEventSource.Log;
if (log.IsEnabled())
{
log.BufferReturned(array.GetHashCode(), array.Length, Id);
if (!(haveBucket & returned))
{
log.BufferDropped(array.GetHashCode(), array.Length, Id,
haveBucket ? bucketIndex : ArrayPoolEventSource.NoBucketId,
haveBucket ? ArrayPoolEventSource.BufferDroppedReason.Full : ArrayPoolEventSource.BufferDroppedReason.OverMaximumSize);
}
}
}
public override void Return(T[] array, bool clearArray = false)
{
if (array is null)
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.array);
}
// Determine with what bucket this array length is associated
int bucketIndex = Utilities.SelectBucketIndex(array.Length);
// Make sure our TLS buckets are initialized. Technically we could avoid doing
// this if the array being returned is erroneous or too large for the pool, but the
// former condition is an error we don't need to optimize for, and the latter is incredibly
// rare, given a max size of 1B elements.
T[]?[] tlsBuckets = t_tlsBuckets ?? InitializeTlsBucketsAndTrimming();
bool haveBucket = false;
bool returned = true;
if ((uint)bucketIndex < (uint)tlsBuckets.Length)
{
haveBucket = true;
// Clear the array if the user requested it.
if (clearArray)
{
Array.Clear(array);
}
// Check to see if the buffer is the correct size for this bucket.
if (array.Length != Utilities.GetMaxSizeForBucket(bucketIndex))
{
throw new ArgumentException(SR.ArgumentException_BufferNotFromPool, nameof(array));
}
// Store the array into the TLS bucket. If there's already an array in it,
// push that array down into the per-core stacks, preferring to keep the latest
// one in TLS for better locality.
T[]? prev = tlsBuckets[bucketIndex];
tlsBuckets[bucketIndex] = array;
if (prev is not null)
{
PerCoreLockedStacks stackBucket = _buckets[bucketIndex] ?? CreatePerCoreLockedStacks(bucketIndex);
returned = stackBucket.TryPush(prev);
}
}
// Log that the buffer was returned
ArrayPoolEventSource log = ArrayPoolEventSource.Log;
if (log.IsEnabled() && array.Length != 0)
{
log.BufferReturned(array.GetHashCode(), array.Length, Id);
if (!(haveBucket & returned))
{
log.BufferDropped(array.GetHashCode(), array.Length, Id,
haveBucket ? bucketIndex : ArrayPoolEventSource.NoBucketId,
haveBucket ? ArrayPoolEventSource.BufferDroppedReason.Full : ArrayPoolEventSource.BufferDroppedReason.OverMaximumSize);
}
}
}
