Hi Flavio, in general, what's this useful for? Debugging, maybe?
Do you expect the process itself to query its threads' names locally, or do you expect another process (GDB) to issue thread_get_name remotely? On Wed, Jul 10, 2024 at 7:04 PM Flavio Cruz <flavioc...@gmail.com> wrote: > diff --git a/htl/pt-internal.h b/htl/pt-internal.h > index 85a7d905..b6ccbe12 100644 > --- a/htl/pt-internal.h > +++ b/htl/pt-internal.h > @@ -105,6 +105,10 @@ struct __pthread > /* Initial sigset for the thread. */ > sigset_t init_sigset; > > + /* Used to store the thread name through pthread_setname_np. */ > + pthread_mutex_t name_lock; I see other members of struct __pthread are also using pthread_mutex_t, but is there really a reason why we need that over a simple libc_lock? > + char *thread_name; Does it make sense to store the name locally? Could pthread_getname_np call thread_get_name also, if we don't expect it to be a frequent operation? Not saying you shouldn't store the name, but let's think of the space vs performance trade-off and document it. If you do store it, you should make sure to free it in pt-dealloc. > + > /* Thread context. */ > struct pthread_mcontext mcontext; > > diff --git a/sysdeps/htl/pthread.h b/sysdeps/htl/pthread.h > index fa626ebc..cf42383f 100644 > --- a/sysdeps/htl/pthread.h > +++ b/sysdeps/htl/pthread.h > @@ -891,6 +891,17 @@ extern int pthread_setschedparam (pthread_t __thr, int > __policy, > /* Set thread THREAD's scheduling priority. */ > extern int pthread_setschedprio (pthread_t __thr, int __prio) __THROW; > > +#ifdef __USE_GNU > +/* Get thread name visible in the kernel and its interfaces. */ > +extern int pthread_getname_np (pthread_t __target_thread, char *__buf, > + size_t __buflen) > + __THROW __nonnull ((2)); __attr_access ((__write_only__, 2, 3)) perhaps? > + > +/* Set thread name visible in the kernel and its interfaces. */ > +extern int pthread_setname_np (pthread_t __target_thread, const char *__name) > + __THROW __nonnull ((2)); Same here, __attr_access ((__read_only__, 2)) > diff --git a/sysdeps/mach/htl/pt-setname-np.c > b/sysdeps/mach/htl/pt-setname-np.c > new file mode 100644 > index 00000000..abc20bf5 > --- /dev/null > +++ b/sysdeps/mach/htl/pt-setname-np.c > @@ -0,0 +1,66 @@ > +/* pthread_setname_np. Mach version. > + Copyright (C) 2024 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#include <ldsodefs.h> > +#include <pthread.h> > +#include <pthreadP.h> > +#include <string.h> > + > +#include <pt-internal.h> > +#include <hurdlock.h> What's hurdlock.h for? > + > +int > +__pthread_setname_np (pthread_t thread, const char *name) > +{ > +#ifdef HAVE_MACH_THREAD_SET_NAME > +/* Same as the Mach kernel's thread name size. */ > +#define THREAD_NAME_SIZE 64 > + struct __pthread *pthread; > + char *oldname, *cp, newname[THREAD_NAME_SIZE]; > + > + /* Lookup the thread structure for THREAD. */ > + pthread = __pthread_getid (thread); > + if (pthread == NULL) > + return ESRCH; > + > + /* Check for overflow and copy the name into a buffer. */ > + if (strlen (name) >= THREAD_NAME_SIZE) > + return ERANGE; > + strncpy (newname, name, THREAD_NAME_SIZE); > + > + oldname = pthread->thread_name; > + cp = strdup (newname); > + if (cp == NULL) > + return ENOMEM; > + > + __pthread_mutex_lock (&pthread->name_lock); > + oldname = pthread->thread_name; > + pthread->thread_name = cp; > + __thread_set_name (pthread->kernel_thread, cp); No checking the return value? > + __pthread_mutex_unlock (&pthread->name_lock); > + > + if (oldname != NULL) > + free (oldname); Nitpick: no need to check for NULL before freeing. Sergey
