What are some examples of using shared locks in programming?

Can you explain what a shared lock is and provide some examples of its usage?

A shared lock allows multiple transactions to read a resource simultaneously while preventing any from writing to it. For example, in a database, if several users need to read data from a table, a shared lock can be applied to allow concurrent reads.

What are some scenarios where using a shared lock would be beneficial?

Using a shared lock is beneficial in scenarios like reporting systems where multiple users need to access the same data for analysis without altering it, or in a web application where many users can view the same content without interference.

Are there any downsides to using shared locks?

Yes, the main downside is that while shared locks allow concurrent reads, they can lead to contention if many transactions are trying to acquire locks simultaneously, potentially causing delays.

How does a shared lock differ from an exclusive lock?

A shared lock allows multiple transactions to read a resource, while an exclusive lock prevents any other transaction from accessing the resource, ensuring that only one transaction can write to it at a time.