hcq pci signal fuzzer (tinygrad#8854)

* hcq pci signal fuzzer

* kk

* correct

Author: nimlgen

test/external/external_fuzz_hcq_signals.py

@@ -0,0 +1,31 @@
+import random
+from tinygrad import Device
+from tinygrad.helpers import getenv, DEBUG
+
+def main():
+  seed = getenv("SEED", 1337)
+  n_gpus = getenv("GPUS", 3)
+  iters = getenv("ITERS", 10000000)
+  only_compute = bool(getenv("ONLY_COMPUTE", 0))
+
+  print(f"{n_gpus} GPUs for {iters} iterations, {only_compute=}, seed {seed}")
+  devs = tuple([Device[f"{Device.DEFAULT}:{x}"] for x in range(n_gpus)])
+
+  for i in range(iters):
+    dev = random.choice(devs)
+    q_t = random.choice([dev.hw_copy_queue_t, dev.hw_compute_queue_t] if not only_compute else [dev.hw_compute_queue_t])
+
+    deps_sigs = random.randint(0, len(devs))
+    wait_devs = random.sample(devs, deps_sigs)
+
+    q = q_t()
+    for d in wait_devs: q.wait(d.timeline_signal, d.timeline_value - 1)
+    q.wait(dev.timeline_signal, dev.timeline_value - 1).signal(dev.timeline_signal, dev.timeline_value).submit(dev)
+    dev.timeline_value += 1
+
+    if sync:=random.randint(0, 10) < 3: dev.synchronize()
+    if DEBUG >= 2: print(f"{i}: {q_t.__name__} {dev.device_id} timeline {dev.timeline_value}, wait for {[d.device_id for d in wait_devs]}, {sync=}")
+    elif i % 100 == 0: print(f"\rCompleted {i} iterations", end='')
+
+if __name__ == "__main__":
+  main()