রিয়েল-টাইম সিস্টেম — হার্ড বনাম সফট রিয়েল-টাইম

class RTTask:
    def __init__(self, name, kind, deadline_ms, completion_ms):
        self.name = name
        self.kind = kind  # "hard" অথবা "soft"
        self.deadline_ms = deadline_ms
        self.completion_ms = completion_ms

    @property
    def lateness_ms(self):
        return self.completion_ms - self.deadline_ms

    def classify(self):
        if self.completion_ms <= self.deadline_ms:
            return "met"
        if self.kind == "hard":
            return "missed-hard"
        return "missed-soft"


tasks = [
    RTTask("Airbag_Deploy",      "hard", deadline_ms=20,  completion_ms=18),
    RTTask("Airbag_Deploy_Rare", "hard", deadline_ms=20,  completion_ms=24),
    RTTask("ABS_Brake_Pulse",    "hard", deadline_ms=10,  completion_ms=10),
    RTTask("Video_Frame_23",     "soft", deadline_ms=33,  completion_ms=41),
    RTTask("Video_Frame_24",     "soft", deadline_ms=33,  completion_ms=30),
    RTTask("Audio_Buffer_Fill",  "soft", deadline_ms=5,   completion_ms=7),
]

results = []
for t in tasks:
    status = t.classify()
    results.append((t, status))
    print(f"{t.name:<20} kind={t.kind:<5} deadline={t.deadline_ms:>3}ms  completion={t.completion_ms:>3}ms  "
          f"lateness={t.lateness_ms:>4}ms  -> {status}")

hard_tasks = [t for t, s in results if t.kind == "hard"]
hard_missed = [t for t, s in results if t.kind == "hard" and s == "missed-hard"]
soft_tasks = [t for t, s in results if t.kind == "soft"]
soft_missed = [t for t, s in results if t.kind == "soft" and s == "missed-soft"]

hard_reliability_pct = 100 * (len(hard_tasks) - len(hard_missed)) / len(hard_tasks)
avg_soft_lateness = sum(max(0, t.lateness_ms) for t in soft_tasks) / len(soft_tasks)

print()
print(f"হার্ড রিয়েল-টাইম টাস্ক: মোট {len(hard_tasks)}টি, মিস হয়েছে {len(hard_missed)}টি "
      f"-> রিলায়েবিলিটি {hard_reliability_pct:.1f}%")
print(f"সফট রিয়েল-টাইম টাস্ক: মোট {len(soft_tasks)}টি, ডেডলাইন মিস {len(soft_missed)}টি, "
      f"গড় লেটনেস {avg_soft_lateness:.1f}ms")

if hard_missed:
    print("\nসতর্কতা: নিচের হার্ড-রিয়েল-টাইম টাস্কগুলো সিস্টেম ফেইলিউর হিসেবে গণ্য হবে:")
    for t in hard_missed:
        print(f"  - {t.name} (deadline {t.deadline_ms}ms, completed {t.completion_ms}ms)")