Can 2 processes have same PID?

Can 2 processes have same PID?

Just a quick question, if I clone a process, the PID of the cloned process is the same, yes ? fork() creates a child process where the PID differs, but everything else is the same. Vfork() creates a child process with the same PID. Exec works to change a process currently in execution to something else.

Can different processes use same threads?

You can (usually) have multiple threads executing concurrently within the same process. Process: Process is a heavy weight process. Process is a separate program that has separate memory,data,resources ect.

Can a thread belong to two processes?

Each thread belongs to exactly one process and no thread can exist outside a process. Each thread represents a separate flow of control.

What happens if you fork a process with multiple threads?

If a multi-threaded process calls fork(), the new process shall contain a replica of the calling thread and its entire address space, possibly including the states of mutexes and other resources.

How does the system call fork () behave for a process with multiple threads?

The fork(2) function creates a copy of the process, all memory pages are copied, open file descriptors are copied etc. So the fork(2) call clones just the thread which executed it.

Does fork () duplicate only the calling thread or all threads?

The fork subroutine duplicates the parent process, but duplicates only the calling thread; the child process is a single-threaded process. The calling thread of the parent process becomes the initial thread of the child process; it may not be the initial thread of the parent process.

How many processes are created by 3 fork?

Fork #2 is executed by two processes, creating two processes, for a total of four. Fork #4 is executed by half of the processes created by fork #3 (so, four of them). This creates four additional processes. You now have twelve processes.

Can a thread belong to the same process?

Threads belonging to the same process, however, do not have such hardware memory-management protection can pretty much share whatever they like, the obvious downside being that they can corrupt pretty much whatever they like.

How is memory shared in a multi-threaded process?

Typically all of the memory inside of a multi-threaded process is “shared” by all of the threads except for some relatively small stack spaces which are per-thread. That is usually the definition of threads in that they all are running within the same memory space.

Can you run two parallel threads at once in Python?

Basically, two different native threads of the same process can’t run Python code at once. Things are not that bad, though, and here’s why: stuff that happens outside the GIL realm is free to be parallel. In this category fall long-running tasks like I/O and, fortunately, libraries like numpy.

Why do we use threads in parallel programming?

Notice how each task is performed in a different process and on the MainThread of that process. Using threads we take advantage of the fact that the tasks can be executed concurrently. The execution time is also cut down to a quarter, even though nothing is running in parallel.