Updated March 30, 2023
Difference Between Coroutines vs Threads
Coroutines vs Threads will showcase the key differences and similarities by comparing both of them. Going through the definition of each, Coroutines is a form of sequential processing, i.e., one gets executed at any given time similar to subroutines. Whereas Threads is a form of concurrent processing, i.e., multiple threads get executed at any given time. In threads, the operating system will switch the running of threads preemptively based on the scheduler. Unlike threads, coroutines will have a programmer, and programming language determines when to switch to coroutines. The difference between coroutines and threads is bigger comparatively.
Head to Head Comparison Between Coroutines vs Threads (Infographics)
Below are the top 15 differences between Coroutines vs Threads:
Key Difference Between Coroutines vs Threads
Let us discuss some of the major key differences between Coroutines vs Threads:
- Coroutines are required to read and parse a file into some meaningful information step by step or line by line or load the entire content in memory.
- Threads are created without replicating the entire process; they are created in user space rather than kernel space.
- Coroutines reschedule at a specific point in the program and avoid concurrent execution. This is considered as advantageous as it is event-driven.
- Threads are not independent of each other; they share code and data section, and OS resources.
- Coroutines are implemented in asynchronous programming and in functional programming.
- Coroutines keep the system utilization at a higher rate comparatively.
- Coroutines can achieve preemptive scheduling and require lesser resources than threads.
- Threads mostly minimize the context switching time and provide concurrency in the process.
- Threads have efficient communication and are more economical in the creation and context switching of threads.
- Threads allow usage of multiprocessor architectures on a bigger scale and efficiency.
- As threads can share common data, they will not need inter process communication, and hence threads have an advantage over multiprocessors.
- User-level threads are implemented in user-level libraries and not in system calls, and hence there is no need of calling the operating system to cause an interruption in the kernel.
- Kernel level threads know and manage threads, and there is no runtime system needed. The kernel has a thread table to have a track of all threads in the system.
- As Kernel threads have knowledge of all threads, the scheduler decides to give more time for a process which has a large number of threads than one with a smaller number of threads.
Coroutines vs Threads Comparison Table
Let’s discuss the top comparison between Coroutines vs Threads:
| Coroutines | Threads |
| A coroutine is a program, one of the cooperative types of subprograms which allows to pause and resume at the time of execution. | Threads, on the other hand, are built-in processes. |
| Coroutines are a form of sequential processing, and one is executed at a time. | Threads are conceptually a form of concurrent processing, i.e., multiple threads get executed at any given time. |
| Coroutines are not bound to any particular thread. | Whereas, for threads, the Operating system switches threads preemptively based on the scheduler. |
| Coroutines start execution in one thread, suspend the execution and resume on other thread. | Whereas a thread can be kept blocked for a certain period of time and cannot be used until its work gets completed. |
| As coroutine is user-friendly and light weight, scheduling is controlled by the user completely. | Thread is a process entity and basic unit of CPU and scheduler dispatch; it can run independently. |
| Coroutine has its own register context and stack. | Thread does not have its own system resources but has few resources that are essential such as a set of registers and stack. |
| When a coroutine scheduler switches, register context and stack are saved to another place. | Threads can share all the resources owned by the process and threads belonging to the same process. |
| In coroutines, the operating stack basically does not have kernel switching overhead and access global variable without a lock. Hence context switching is faster. | In threads, communication is through shared memory. Hence context switching is faster, resource overhead is less, but the process is not stable enough and losses data easily. |
| Coroutines are Asynchronous. | Threads are of Synchronous mechanism. |
| Coroutines have user-mode memory space given by threads for data storage. | Threads have Kernel memory space for data storage. |
| Application code in Coroutines uses code for on-site storage and restoration. | Switch operation is completed in the Kernel layer itself, and the application layer will call syscall, underlying functions given by the kernel layer. |
| In Coroutines, task scheduling is carried out by a specific scheduler for user-mode realization. | In Threads, task scheduling is realized by Kernel, preemptive mode depending on various locks. |
| Coroutines have a voice support level for few programming languages such as Go, Python, Lua, etc. | Threads have a voice support level for most of the programming languages. |
| In coroutines, there is no uniform specification, and implemented by developers at the application layer and is customizable. | For threads, implementation specifications change according to modern operating system specifications. |
| Coroutines use a function call and resumed later. | Threads use interrupt-based events to change context compared to what coroutines use. |
Conclusion
With this, we shall conclude the topic “Coroutines vs Threads”. We have seen the definition of Coroutines vs Threads and what each one means. Next, we have seen a comparison table listing the similarities or differences for coroutines and threads and listed a few of the key differences among both.
Recommended Articles
This is a guide to Coroutines vs Threads. Here we discuss key differences with infographics and comparison tables, respectively. You may also have a look at the following articles to learn more –
