"""My process's share of GPU time over a span — the #146 admissibility rule.

accumulatedGPUTime is cumulative since client creation, so WindowServer always
dominates the totals. The question that decides whether a rail reading may be
attributed to this process is the DELTA over the measured span.
"""
import re, subprocess, time, os, sys, threading

def gpu_times():
    out = subprocess.run(["ioreg","-r","-c","IOAccelerator","-l","-w0"],
                         capture_output=True, text=True, timeout=30).stdout
    tot = {}
    for b in out.split("IOUserClientCreator")[1:]:
        m = re.search(r'pid (\d+), ([^"]+)', b)
        if not m: continue
        key = (int(m.group(1)), m.group(2).strip())
        g = sum(int(x) for x in re.findall(r'"accumulatedGPUTime"\s*=\s*(\d+)', b[:4000]))
        if g: tot[key] = tot.get(key, 0) + g
    return tot

def load(stop):
    import mlx.core as mx
    a = mx.random.normal((2048,2048)); b = mx.random.normal((2048,2048))
    while not stop.is_set():
        mx.eval(a @ b)

me = os.getpid()
stop = threading.Event()
t = threading.Thread(target=load, args=(stop,), daemon=True); t.start()
time.sleep(0.5)
before = gpu_times(); t0 = time.perf_counter()
time.sleep(4.0)
after = gpu_times(); span = time.perf_counter() - t0
stop.set(); t.join(timeout=3)

delta = {}
for k, v in after.items():
    d = v - before.get(k, 0)
    if d > 0: delta[k] = d
s = sum(delta.values())
mine = sum(v for (pid, _n), v in delta.items() if pid == me)
print(f"span {span:.2f}s   clients advancing: {len(delta)}   total GPU time in span: {s/1e9:.3f}s")
print(f"this process (pid {me}): {mine/1e9:.3f}s = {100*mine/s if s else 0:.1f}% of GPU time in the span")
for (pid, n), v in sorted(delta.items(), key=lambda kv: -kv[1])[:6]:
    tag = "  <-- me" if pid == me else ""
    print(f"   pid {pid:>7}  {n[:34]:<34} {v/1e9:>8.3f}s  {100*v/s:>5.1f}%{tag}")
print()
print("#146 rule:", "HwShunt (>=99%)" if s and mine/s >= 0.99 else
      ("exactly 0 (no GPU time)" if mine == 0 else "NO GPU FIGURE — span is CPU only, Partial"))