I can't find any support for your comment that "Fork creates a new process and therefore also a new thread." From the Linux man pages https://www.man7.org/linux/man-pages/man2/fork.2.html, "The child process is created with a single thread—the one that called fork()."
I have a one-core one-thread instance at Digital Ocean available running Ubuntu 18.04. I can fork and create a new process on it, but it doesn't create a new thread because it doesn't have one available. You may also want to see "Forking vs Threading" (https://www.geekride.com/fork-forking-vs-threading-thread-linux-kernel), "Fork vs Thread" (https://medium.com/obscure-system/fork-vs-thread-38e09ec099e2), and "Linux process and thread" (https://zliu.org/post/linux-process-and-thread) ("This means that to create a normal process fork() is used that further calls clone() with appropriate arguments while to create a thread or LWP, a function from pthread library calls clone() with relvant flags. So, the main difference is generated by using different flags that can be passed to clone() funciton(to be exact, it is a system call"). You may be confused by the fact that threads are called light-weight processes. Or maybe I'm confused :) If you have other information, please let me know. Thanks. Jen Dec 5, 2021, 18:08 by hjp-pyt...@hjp.at: > On 2021-12-06 00:51:13 +0100, Jen Kris via Python-list wrote: > >> The C program creates two threads (using pthreads), one for itself and >> one for the child process. On creation, the second pthread is pointed >> to a C program that calls fork-execv to run the Python program. That >> way Python runs on a separate thread. >> > > I think you have the relationship between processes and threads > backwards. A process consists of one or more threads. Fork creates a new > process and therefore also a new thread. > > hp > > -- > _ | Peter J. Holzer | Story must make more sense than reality. > |_|_) | | > | | | h...@hjp.at | -- Charles Stross, "Creative writing > __/ | http://www.hjp.at/ | challenge!" > -- https://mail.python.org/mailman/listinfo/python-list
