public MemoryAllocation GetMemoryFor(int requiredSizeInBytes, MemoryFlag flags, IntPtr data, int data_size_in_bytes = -1)
{
if (!IsInitialized())
{
return(null);
}
var accessFlags = flags & (MemoryFlag.ReadOnly | MemoryFlag.WriteOnly | MemoryFlag.ReadWrite);
MemoryAllocation candidate = null;
uint bestMatchingSize = uint.MaxValue;
int itemToSwap = -1;
for (int i = 0; i < freeMemoryAllocations.Count; i++)
{
var item = freeMemoryAllocations[i];
if (item.flags == accessFlags && item.bufferSizeInBytes >= requiredSizeInBytes && item.bufferSizeInBytes < bestMatchingSize) //Select the smallest sufficient memory allocation from our allocations
{
bestMatchingSize = item.bufferSizeInBytes;
candidate = item;
itemToSwap = i;
if (item.bufferSizeInBytes == requiredSizeInBytes)
{
break;
}
}
}
if (candidate == null)
{
candidate = CreateMemoryAllocation(clContext, (uint)requiredSizeInBytes, accessFlags, IntPtr.Zero);
usedMemoryAllocations.Add(candidate);
}
else
{
freeMemoryAllocations.RemoveAt(itemToSwap);
usedMemoryAllocations.Add(candidate);
}
if (flags.HasFlag(MemoryFlag.CopyHostPointer) && data != IntPtr.Zero)
{
int upload_size_in_bytes = data_size_in_bytes >= 0 ? data_size_in_bytes : requiredSizeInBytes;
IntPtr ev = IntPtr.Zero;
var errCodeWrite = EnqueuedCommandsNativeApi.EnqueueWriteBuffer(commandQueue, candidate.buffer, 0U, UIntPtr.Zero, new UIntPtr((uint)upload_size_in_bytes), data, 0, null, out ev);
ThrowOnError(errCodeWrite, String.Format("Failed to enqueue write buffer. Write-size:{0}, Target buffer size: {1}", requiredSizeInBytes, candidate.bufferSizeInBytes));
var errCodeEv = EventsNativeApi.ReleaseEvent(ev);
ThrowOnError(errCodeEv, String.Format("Failed release event (EnqueueWriteBuffer)"));
}
return(candidate);
}
