//! UI-thread priority boost (docs/BUGS/scroll-jank-120hz.md §4.1, egui
//! port). The phone's default UI-thread priority (nice 0) gets descheduled
//! 30–100 ms under ambient load — the measured stall class. `set_self_nice`
//! sets the CALLING thread to nice -10 (the UI thread) or +2 (the decode
//! threads, so they never compete with the UI thread).
//!
//! Bionic's `setpriority(PRIO_THREAD, 0, n)` acts on exactly the calling
//! thread (no /proc, no JNI — the old Slint build needed a JNI
//! `setThreadPriority` round-trip for foreign threads; winit 0.30 runs the
//! loop on the calling thread itself, so nothing foreign ever needs
//! adjusting).

#[cfg(target_os = "android")]
extern "C" {
    fn setpriority(which: i32, who: u32, prio: i32) -> i32;
}

#[cfg(target_os = "android")]
pub fn set_self_nice(nice: i32) {
    const PRIO_THREAD: i32 = 5;
    unsafe {
        setpriority(PRIO_THREAD, 0, nice);
    }
}

#[cfg(not(target_os = "android"))]
pub fn set_self_nice(_nice: i32) {}