[Apex] How do I handle concurrency and multi-threading in Apex?

Apex, the programming language used in Salesforce, is not inherently designed for multi-threading. However, you can achieve concurrency by using Asynchronous Apex and Batch Apex.

  1. Asynchronous Apex:

    • Use the @future annotation to define a method that runs asynchronously in the background.
    • This method can be invoked from a trigger, a Visualforce page, or an Apex class.
  2. Batch Apex:

    • Implement the Database.Batchable interface to process large sets of data asynchronously.
    • Batch Apex jobs can be scheduled to run at specific times or be kicked off manually.
  3. Queueable Apex:

    • Use the Queueable interface to queue jobs and execute them in the background.
    • This is useful when you need to chain multiple jobs together.
  4. Schedulable Apex:

    • Use the Schedulable interface to schedule the execution of a class at specific intervals.
    • This allows you to automate repetitive tasks.

Remember to consider the governor limits enforced by Salesforce when implementing concurrency and multi-threading in Apex. These limits include the number of asynchronous and batch Apex jobs that can be executed per day, as well as limits on CPU time and heap size usage.

Additionally, ensure that you handle any potential conflicts when updating shared records or data. You can use locking mechanisms like the FOR UPDATE clause or system-level locks to prevent data inconsistencies.

It's important to thoroughly test your code to ensure that it performs as expected and handles concurrency scenarios appropriately.