SampleLoad leaks pinned GC handles

[smoogipoo]

BASS_ChannelSetSync is documented as accepting a channel handle of type HMUSIC, HSTREAM or HRECORD.
BASS_SampleLoad returns an HSAMPLE.

ManagedBass's overload for SampleLoad which takes a byte[] pins the handle then binds to ChannelSetSync and frees only when a Free sync callback is invoked:

ManagedBass/src/Bass/Shared/Bass/PInvoke/Samples.cs

Lines 461 to 464 in 0cdc873

	public static int SampleLoad(byte[] Memory, long Offset, int Length, int MaxNoOfPlaybacks, BassFlags Flags)
	{
	return GCPin.CreateStreamHelper(Pointer => SampleLoad(Pointer, Offset, Length, MaxNoOfPlaybacks, Flags), Memory);
	}

ManagedBass/src/Bass/Shared/GCPin.cs

Lines 27 to 38 in 0cdc873

	public static int CreateStreamHelper(Func<IntPtr, int> Function, object Memory)
	{
	var GCPin = GCHandle.Alloc(Memory, GCHandleType.Pinned);
	var Handle = Function(GCPin.AddrOfPinnedObject());
	if (Handle == 0)
	GCPin.Free();
	else Bass.ChannelSetSync(Handle, SyncFlags.Free, 0, (a, b, c, d) => GCPin.Free());
	return Handle;
	}

Bass.LastError will also be set to Errors.Handle after the call to Bass.ChannelSetSync, in confirmation of the issue. As per the above, this leaks the pinned memory handle.

[olitee]

Closing since PR has been merged into the codebase. Thanks @smoogipoo

[smoogipoo]

@olitee I believe this is still an issue. Unless I've missed something, the above merged PR is a workaround added to our own project, because I haven't had the time to address this in ManagedBass itself.