C# multithreading 🧶

C# Multi-threading Fundamentals
📌 A thread is defined as an execution path of a program, allowing multiple tasks to run concurrently.
⚙️ Every program starts with a single thread named the main thread.
🛠️ To implement threading, one must include `using System.Threading;` at the top of the code.
💡 The `Thread.Sleep()` method can pause the current thread for a specified number of milliseconds (e.g., 1000ms for one second).

Demonstration: Concurrent Timers
🛑 When both `CountDown` and `CountUp` methods run sequentially on the main thread, the second operation waits for the first to complete.
🏃 To achieve concurrent execution, additional threads must be created to handle each task independently.
🚀 Threads are initiated by creating a `new Thread()` object, passing the target method to the constructor, and then invoking the `.Start()` method on each thread instance.

Handling Methods with Parameters
🔧 When a target method requires parameters, it is necessary to use a lambda expression within the thread constructor.
➡️ The lambda expression format is `() => MethodName(arguments)`, allowing parameters like "timer number one" to be passed to the designated thread task.

Key Points & Insights
➡️ A thread enables a program to execute different tasks simultaneously rather than sequentially.
➡️ To run tasks concurrently (e.g., one counting up and one counting down), instantiate separate `Thread` objects for each task and call their `.Start()` methods.
➡️ Methods requiring parameters when used in multi-threading should utilize a lambda expression within the `Thread` constructor to correctly pass arguments.

📸 Video summarized with SummaryTube.com on Feb 18, 2026, 17:30 UTC