> 1.there is no direct kernel support for threads. Linux kernel do not see threads per se, but only processes. For any thread in userspace, there would be a task_struct in the kernel. The mm/active_mm should be shared among different threads. > 2.pthreads is the most popular threads library in linux. See the reference to ntpl in Tyler's mail > 3.it uses the clone system call to create "threads" which are > just another process that shares its creator's memory space. yes. clone end up calling a sys_clone which in turn calls do_form with some flags specific to clone-ing like CLONE_VM. I mean to say the implementaion of clone-is a subset of fork(), thus creating an instance of proc_struct. > > 4.the kernel sees these "threads" as just another process, > and schedules them like an autonomous process in the system. > 5. all pthread does is handle synchronizing, message passing, etc, > between the threads. it does not responsible for their scheduling ? I do not know exactly, but it is almost right. In scheduler code I did not see anything to differenciate among processes of a thread and independent processes. But I can be wrong. > > and last but not least, and forgive me if it is out of context a little: > 6. where can I find the sources of phtread ? > 7. is there another popular threads implementation in linux I should > look at ? it's a jungle out there... >From Fedora 5 onwards pthreads are deprecated. NPTL support has been in place for quite some time. Other distros may follow/ alread lead. Maybe you should concentrate more on nptl. Regards, om. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
