From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/10486 Path: news.gmane.org!.POSTED!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: [PATCH v2] add pthread_setname_np Date: Fri, 16 Sep 2016 22:36:49 -0400 Message-ID: <20160917023648.GW15995@brightrain.aerifal.cx> References: <20160917005400.GA475@nyan> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: blaine.gmane.org 1474079828 14322 195.159.176.226 (17 Sep 2016 02:37:08 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 17 Sep 2016 02:37:08 +0000 (UTC) User-Agent: Mutt/1.5.21 (2010-09-15) To: musl@lists.openwall.com Original-X-From: musl-return-10499-gllmg-musl=m.gmane.org@lists.openwall.com Sat Sep 17 04:37:04 2016 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.84_2) (envelope-from ) id 1bl5Uz-0002wI-P2 for gllmg-musl@m.gmane.org; Sat, 17 Sep 2016 04:37:01 +0200 Original-Received: (qmail 8000 invoked by uid 550); 17 Sep 2016 02:37:01 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 7965 invoked from network); 17 Sep 2016 02:37:01 -0000 Content-Disposition: inline In-Reply-To: <20160917005400.GA475@nyan> Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:10486 Archived-At: On Fri, Sep 16, 2016 at 08:54:00PM -0400, Felix Janda wrote: > the thread name is displayed by gdb's "info threads". > --- > v1->v2: add _GNU_SOURCE, and "UL" to prctl arguments > > I hope that there are no programs for which this function is > performance critical... > > Thanks for the review so far! > --- > include/pthread.h | 1 + > src/thread/pthread_setname_np.c | 26 ++++++++++++++++++++++++++ > 2 files changed, 27 insertions(+) > create mode 100644 src/thread/pthread_setname_np.c > > diff --git a/include/pthread.h b/include/pthread.h > index 3d2e0c4..94ef919 100644 > --- a/include/pthread.h > +++ b/include/pthread.h > @@ -214,6 +214,7 @@ struct cpu_set_t; > int pthread_getaffinity_np(pthread_t, size_t, struct cpu_set_t *); > int pthread_setaffinity_np(pthread_t, size_t, const struct cpu_set_t *); > int pthread_getattr_np(pthread_t, pthread_attr_t *); > +int pthread_setname_np(pthread_t, const char *); > int pthread_tryjoin_np(pthread_t, void **); > int pthread_timedjoin_np(pthread_t, void **, const struct timespec *); > #endif > diff --git a/src/thread/pthread_setname_np.c b/src/thread/pthread_setname_np.c > new file mode 100644 > index 0000000..82d35e1 > --- /dev/null > +++ b/src/thread/pthread_setname_np.c > @@ -0,0 +1,26 @@ > +#define _GNU_SOURCE > +#include > +#include > +#include > +#include > + > +#include "pthread_impl.h" > + > +int pthread_setname_np(pthread_t thread, const char *name) > +{ > + int fd, cs, status = 0; > + char f[sizeof "/proc/self/task//comm" + 3*sizeof(int)]; > + size_t len; > + > + if ((len = strnlen(name, 16)) > 15) return ERANGE; > + > + if (thread == pthread_self()) > + return prctl(PR_SET_NAME, (unsigned long)name, 0UL, 0UL, 0UL) ? errno : 0; > + > + snprintf(f, sizeof f, "/proc/self/task/%d/comm", thread->tid); > + pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); > + if ((fd = open(f, O_WRONLY)) < 0 || write(fd, name, len) < 0) status = errno; > + if (fd >= 0) close(fd); > + pthread_setcancelstate(cs, 0); > + return status; > +} > -- > 2.7.3 I don't see anything left that particularly needs changing. I'll see if anyone else has comments and commit if not. I did just notice that my hopes that the function could be implemented with just public APIs aren't met, since thread->tid is needed. But this could be fixed in the future if there's ever consensus on a pthread_gettid_np function. Rich