Single-threaded means that a program or application is designed to run using a single thread of execution. A thread is a unit of execution within a program that runs instructions sequentially.
In a single-threaded application, there is only one thread of execution, which means that the program can only execute one task at a time. For example, if a program is processing a long task, such as downloading a large file, it may not be able to respond to other user input until the task is complete.
Single-threaded applications are often simpler to develop and maintain than multi-threaded applications because they do not require complex synchronization mechanisms to manage concurrent access to shared resources. However, single-threaded applications can also be less efficient, especially if they spend a lot of time waiting for I/O operations to complete.
Node.js is an example of a single-threaded application that uses asynchronous programming to handle multiple concurrent requests. By using an event-driven, non-blocking I/O model, Node.js is able to maximize the efficiency of the single thread and handle many concurrent connections without the need for additional threads.
Node.js is single-threaded in the sense that it uses a single thread to handle all incoming requests and execute code. However, it does make use of asynchronous programming to handle multiple requests simultaneously.
Node.js uses an event-driven, non-blocking I/O model, which means that it can handle many concurrent connections without the need for additional threads. When a new request comes in, Node.js adds it to an event loop, which manages the execution of all incoming requests. The event loop checks for new events and executes any callbacks associated with them, such as handling an incoming request or completing a database query.
Node.js uses a single thread to handle the event loop, which means that it can handle many requests simultaneously without the need for additional threads. By using non-blocking I/O operations, Node.js can perform other tasks while waiting for I/O operations to complete, which helps to maximize the efficiency of the single thread.
However, it’s important to note that some tasks, such as intensive calculations or CPU-bound operations, can block the event loop and impact the performance of the entire application. To mitigate this, Node.js provides a way to delegate such tasks to worker threads or child processes, which can run in parallel with the main event loop and prevent blocking.