/// <inheritdoc />
internal override MemoryGroup <T> AllocateGroup <T>(
long totalLength,
int bufferAlignment,
AllocationOptions options = AllocationOptions.None)
{
long totalLengthInBytes = totalLength * Unsafe.SizeOf <T>();
if (totalLengthInBytes <= this.sharedArrayPoolThresholdInBytes)
{
var buffer = new SharedArrayPoolBuffer <T>((int)totalLength);
return(MemoryGroup <T> .CreateContiguous(buffer, options.Has(AllocationOptions.Clean)));
}
if (totalLengthInBytes <= this.poolBufferSizeInBytes)
{
// Optimized path renting single array from the pool
UnmanagedMemoryHandle mem = this.pool.Rent();
if (mem.IsValid)
{
UnmanagedBuffer <T> buffer = this.pool.CreateGuardedBuffer <T>(mem, (int)totalLength, options.Has(AllocationOptions.Clean));
return(MemoryGroup <T> .CreateContiguous(buffer, options.Has(AllocationOptions.Clean)));
}
}
// Attempt to rent the whole group from the pool, allocate a group of unmanaged buffers if the attempt fails:
if (MemoryGroup <T> .TryAllocate(this.pool, totalLength, bufferAlignment, options, out MemoryGroup <T> poolGroup))
{
return(poolGroup);
}
return(MemoryGroup <T> .Allocate(this.nonPoolAllocator, totalLength, bufferAlignment, options));
}
/// <inheritdoc />
public override IMemoryOwner <T> Allocate <T>(
int length,
AllocationOptions options = AllocationOptions.None)
{
Guard.MustBeGreaterThanOrEqualTo(length, 0, nameof(length));
int lengthInBytes = length * Unsafe.SizeOf <T>();
if (lengthInBytes <= this.sharedArrayPoolThresholdInBytes)
{
var buffer = new SharedArrayPoolBuffer <T>(length);
if (options.Has(AllocationOptions.Clean))
{
buffer.GetSpan().Clear();
}
return(buffer);
}
if (lengthInBytes <= this.poolBufferSizeInBytes)
{
UnmanagedMemoryHandle mem = this.pool.Rent();
if (mem.IsValid)
{
UnmanagedBuffer <T> buffer = this.pool.CreateGuardedBuffer <T>(mem, length, options.Has(AllocationOptions.Clean));
return(buffer);
}
}
return(this.nonPoolAllocator.Allocate <T>(length, options));
}
static void RunTest()
{
using (var buffer = new SharedArrayPoolBuffer <byte>(900))
{
Assert.Equal(900, buffer.GetSpan().Length);
buffer.GetSpan().Fill(42);
}
byte[] array = ArrayPool <byte> .Shared.Rent(900);
byte[] expected = Enumerable.Repeat((byte)42, 900).ToArray();
Assert.True(expected.AsSpan().SequenceEqual(array.AsSpan(0, 900)));
}
