On Wed, Nov 20, 2002 at 09:59:27PM +0200, Osman Çinar Eren wrote: > that should probably be the thread created by the kernel to deal all the > threads created by your program. > regards. It's not created by the kernel implicitly (remember, threads are just normal processes that share some stuff and clone is just an extended fork). It's created by the pthread library as a master thread to coordinate thread attaching and detaching (found this out by looking in the code). I think it's because the interface requires that any thread can join any other thread. But linux only supports waiting for children. So when pthread library is first used, it starts a master thread that then clones the actual threads (actualy, the original process must become the master and the first child continues it's work) > -----Original Message----- > From: Nguyen, NguyenX D [mailto:nguyenx.d.nguyen@intel.com] > Sent: Wednesday, November 20, 2002 9:53 PM > To: kernelnewbies@nl.linux.org > Subject: pthread_create creating 2 threads on first call > > > Hello folks, > > I have a simple demo program that call pthread_create > 5 times with identical parameters. On the FIRST call > to pthread_create, two threads are created. One of these > thread is what I am expecting. On subsequent call to > pthread_create, only one thread is created as expected. > > Does anyone happen to know why on the FIRST call to > pthread_create, two threads are created? What does the > extra one do? Many thanks! > > - Nguyen > > ps: I am compiling with the -pthread switch. > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > ------------------------------------------------------------------------------- Jan 'Bulb' Hudec <bulb@ucw.cz> -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
