Function link_points 

pub fn link_points(
    p: &SpatialProgram,
    chip: u16,
    transfers: &[ChipTransfer],
) -> Result<Vec<LinkPoint>, TpReject>

Where chip chip’s program p halts for transfers: each tensor it sends, after the last section that stores it; each it receives, before the first section that loads it — None for the first section, the host’s to put there before the chip starts. Halts at one boundary are one LinkPoint; they come in program order.