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Concurrency & performance

asyncio, threading, multiprocessing, and profiling-friendly performance patterns.

6 matches

How to Use a Bounded Buffer with threading.Condition in Python

Implement a thread-safe bounded buffer using threading.Condition and show a producer–consumer example with exact output.

threading condition producer-consumer

Python

import threading
import time
import random

class BoundedBuffer:
    def __init__(self, capacity):
        self.capacity = capacity
        self.buffer = []
        self.condition = threading.Condition()

    def put(self, item):
        with self.condition:
            while len(self.buffer) >= self.capacity:
       …

14 0 Open

Concurrency & performance medium

How to Use asyncio Lock to Protect a Shared Counter in Python

This code demonstrates how to use an asyncio.Lock to safely increment a shared counter from multiple concurrent coroutines.

asyncio lock concurrency

Python

import asyncio

async def increment(counter, lock, increments):
    for _ in range(increments):
        async with lock:
            counter[0] += 1

async def main():
    counter = [0]
    lock = asyncio.Lock()
    tasks = [
        increment(counter, lock, 1000)
        for _ in range(5)
    ]
    await asyncio.gath…

17 0 Open

Concurrency & performance easy

How to Use threading.Lock to Synchronize a Counter in Python

Safely increment a shared counter across multiple threads using threading.Lock as a mutex to prevent race conditions.

threading lock mutex

Python

import threading

counter = 0
lock = threading.Lock()

def increment():
    global counter
    for _ in range(100000):
        with lock:
            counter += 1

threads = [threading.Thread(target=increment) for _ in range(5)]
for t in threads:
    t.start()
for t in threads:
    t.join()

print(f"Final counter valu…

14 0 Open

Concurrency & performance medium

How to Use threading.RLock in Python

Demonstrates threading.RLock, a reentrant lock that allows the same thread to acquire it multiple times without deadlocking — essential for recursive functions sharing state across threads.

threading rlock concurrency

Python

import threading
import time

lock = threading.RLock()
shared_counter = 0

def recursive_increment(value, depth):
    global shared_counter
    with lock:
        shared_counter += 1
        print(f"Depth {depth}: counter = {shared_counter}")
        if depth > 1:
            recursive_increment(value, depth - 1)

def…

14 0 Open

Concurrency & performance easy

Synchronize Threads with a Barrier in Python

Demonstrates using threading.Barrier to synchronize multiple threads at phase boundaries, ensuring all workers wait for each other before proceeding.

threading synchronization barrier

Python

import threading
import time
from random import randint

def worker(barrier, worker_id):
    for phase in range(3):
        time.sleep(randint(1, 3))
        print(f"Worker {worker_id} finished phase {phase} at {time.time():.2f}")
        barrier.wait()
    print(f"Worker {worker_id}: all phases complete")

if __name_…

14 0 Open

Concurrency & performance medium

asyncio Condition wait notify pattern in Python

Coordinate coroutines with asyncio.Condition: workers wait for notifications and the main task notifies one or all of them.

asyncio concurrency synchronization

Python

import asyncio


async def worker(condition, name):
    async with condition:
        print(f"{name} waiting...")
        await condition.wait()
        print(f"{name} notified!")


async def main():
    condition = asyncio.Condition()
    tasks = [asyncio.create_task(worker(condition, f"worker-{i}")) for i in range(3…

14 0 Open

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