What are reader-writer locks in programming?

Can you explain what reader-writer locks are in programming?

Sure! Reader-writer locks are synchronization primitives that allow concurrent access to a resource. They differentiate between read and write operations.

How do they improve performance compared to regular locks?

They allow multiple readers to access the resource simultaneously, which improves performance when reads are more frequent than writes.

Can you give me an example of how to implement a reader-writer lock in code?

Certainly! In Python, you can use the threading module with RLock for a simple implementation. Would you like to see a code snippet?

Yes, please provide the code snippet!

Here's a basic example:

import threading

class ReaderWriterLock:
    def __init__(self):
        self.readers = 0
        self.lock = threading.Lock()
        self.write_lock = threading.Lock()

    def acquire_read(self):
        with self.lock:
            self.readers += 1
            if self.readers == 1:
                self.write_lock.acquire()

    def release_read(self):
        with self.lock:
            self.readers -= 1
            if self.readers == 0:
                self.write_lock.release()

    def acquire_write(self):
        self.write_lock.acquire()

    def release_write(self):
        self.write_lock.release()

This code defines a simple reader-writer lock.