Preventing simultaneous timer functions in Discord bot using Python

[SkippingLeaf]

I’m working on a Discord bot that has a timer feature, but I’m running into an issue where users can start multiple timers at the same time. I need to limit it so only one timer can run at a time.

Here’s my current implementation:

import discord
import asyncio

async def start_timer(parameters, msg, bot, command):
    await bot.send_message(msg.channel, "Timer: 10 minutes remaining")
    await asyncio.sleep(120)
    await bot.send_message(msg.channel, "Timer: 8 minutes remaining")
    await asyncio.sleep(120)
    await bot.send_message(msg.channel, "Timer: 6 minutes remaining")
    await asyncio.sleep(120)
    await bot.send_message(msg.channel, "Timer: 4 minutes remaining")
    await asyncio.sleep(60)
    await bot.send_message(msg.channel, "Timer: 3 minutes remaining")
    await asyncio.sleep(60)
    await bot.send_message(msg.channel, "Timer: 2 minutes remaining")
    await asyncio.sleep(45)
    await bot.send_message(msg.channel, "Timer: 1 minute remaining")
    await asyncio.sleep(30)
    await bot.send_message(msg.channel, "Timer: 30 seconds left")

# Error message for when timer is active
# await bot.send_message(msg.channel, embed=discord.Embed(color=discord.Color.orange(), description="Timer is currently active! Please wait until it finishes."))

Right now multiple users can trigger this timer function simultaneously, which creates chaos in the channel. How can I implement a check to ensure only one timer runs at a time?

[AdventurousHiker17]

you could also use asyncio.Event or asyncio.Lock for better thread safety. create timer_lock = asyncio.Lock() at the top, then wrap your timer code with async with timer_lock:. if someone tries starting another timer while one’s running, it’ll wait automatically. or use try_acquire() to reject it immediately. works better than boolean flags for preventing race conditions.

[alexlee]

Just use a boolean flag to track if your timer’s running. Set up a global variable like timer_active = False and check it before starting. Flip it to True when the timer starts, back to False when it’s done:

timer_active = False

async def start_timer(parameters, msg, bot, command):
    global timer_active
    if timer_active:
        await bot.send_message(msg.channel, embed=discord.Embed(color=discord.Color.orange(), description="Timer is currently active! Please wait until it finishes."))
        return
    
    timer_active = True
    try:
        # your existing timer code here
        await bot.send_message(msg.channel, "Timer: 10 minutes remaining")
        # ... rest of your timer logic
    finally:
        timer_active = False

The try/finally block makes sure the flag gets reset even if something breaks. Simple solution that’ll fix your simultaneous timer issue without making things complicated.

[Pete_Magic]

You can also store the timer task itself and check if it’s running. Use asyncio.create_task() to get a reference to your timer coroutine, then check its status before starting a new one:

current_timer = None

async def start_timer(parameters, msg, bot, command):
    global current_timer
    if current_timer and not current_timer.done():
        await bot.send_message(msg.channel, embed=discord.Embed(color=discord.Color.orange(), description="Timer is currently active! Please wait until it finishes."))
        return
    
    current_timer = asyncio.create_task(run_timer(msg, bot))
    await current_timer

This gives you more control over the timer lifecycle. You can cancel the existing timer with current_timer.cancel() for admin commands, which beats just tracking state with flags.