[Solved] Multithreading is an extension of multiprocessing?

Question

Well, yes, to some extent this is true. But it’s a simplified statement, there are significant differences. Shortly…

Multiprocessing

Processes are isolated from each other by OS. Each process has its own virtual memory space. They need to use IPC methods for communication with each other. If a process encounters e.g. segmentation fault, only this process is terminated. Processes can run under various users and permissions.

Multithreading

Threads run within a single process. Each thread has its own stack memory but heap memory can be accessed by various threads since it’s common for the whole process (i.e. various threads). Heap memory can therefore be used for communication. Threads have smaller context so switching them is more lightweight than switching processes. On the other hand all the threads run within one process and therefore under the same user, with the same permissions and if one of the threads encounters segmentation fault (or another error), all the threads are terminated.

Accepted Answer

Well, yes, to some extent this is true. But it’s a simplified statement, there are significant differences. Shortly…

Multiprocessing

Processes are isolated from each other by OS. Each process has its own virtual memory space. They need to use IPC methods for communication with each other. If a process encounters e.g. segmentation fault, only this process is terminated. Processes can run under various users and permissions.

Multithreading

Threads run within a single process. Each thread has its own stack memory but heap memory can be accessed by various threads since it’s common for the whole process (i.e. various threads). Heap memory can therefore be used for communication. Threads have smaller context so switching them is more lightweight than switching processes. On the other hand all the threads run within one process and therefore under the same user, with the same permissions and if one of the threads encounters segmentation fault (or another error), all the threads are terminated.