[Solved] Consider this simplified booking flow code snippet:def book_slot(slot_id): if is_available(slot_id): reserve(slot_id) confirm_booking(slot_id) return 'Booked' else:... | LLD

LLD - Design — Hotel Booking System

Consider this simplified booking flow code snippet:

def book_slot(slot_id):
    if is_available(slot_id):
        reserve(slot_id)
        confirm_booking(slot_id)
        return 'Booked'
    else:
        return 'Unavailable'

What issue can arise if two users call book_slot at the same time for the same slot_id?

ABoth users might get 'Booked' causing double booking

BThe system crashes due to race condition

CBoth users get 'Unavailable' response

DOnly one user can call the function at a time automatically

Step-by-Step Solution

Solution:

Step 1: Analyze the code flow for concurrency
Both users check availability before reservation without locking, so both may see the slot as available.
Step 2: Understand race condition effect
Without locking, both reserve and confirm booking, causing double booking.
Final Answer:
Both users might get 'Booked' causing double booking -> Option A
Quick Check:
Race condition = double booking risk [OK]

Quick Trick: Check-then-act without lock causes double booking [OK]

Common Mistakes:

MISTAKES

Assuming system crashes automatically
Thinking both get 'Unavailable' response
Believing function serializes calls automatically

Master "Design — Hotel Booking System" in LLD

9 interactive learning modes - each teaches the same concept differently

Learn Why Deep Arch Try Challenge Design Recall Scale

More LLD Quizzes

Consider this simplified booking flow code snippet:

Step 1: Analyze the code flow for concurrency

Step 2: Understand race condition effect

Final Answer:

Quick Check:

Want More Practice?