pub fn wait_slot_empty()Expand description
Block until the handler has kicked the published frame. Spins only when the CPU is a whole frame ahead of presentation. Not inlined, so a profile can tell the spin from work.
Bounded: with no psx-rt handler running (the counter never installed, or interrupts masked) nothing kicks the frame and the VBlank stall test never fires, so the wait gives up after a few million reads and asserts in a debug build.