Amit, the threading library on Linux is a a bit different from the normal 'threads'. Strictly threads are not children of a process as a fork(...) does. When a child of a process terminated, the parent process gets a SIGCHLD. However when a thread terminates is doesn't. The way threading is implemented on linux (where every thread is represented as a child) is a quirk. The thread (though it appears as a child) is in fact *not a true cild* of the process hence waitpid(...) rightly returns. You shouldn't be using waitpid(...) to wait on a thread rather use pthread_join(...) but then you need to pass on the pthread_t that you got when you created it. -Sharath --- Amit Nadgar <vangough_spinlock@yahoo.com> wrote: > hi, > I am trying to do a ptrace on a thread. Ptrace > returns successfully. However when I do a waitpid > where pid I pass is the pid of the thread I wait > returns immediately. When I use the same program on > a > unthreaded process it works fine. > Can anybody help me with this? > > > __________________________________________________ > Do you Yahoo!? > Yahoo! Mail Plus - Powerful. Affordable. Sign up > now. > http://mailplus.yahoo.com > -- > Kernelnewbies: Help each other learn about the Linux > kernel. > Archive: > http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
