From: Robert Pluim <rpluim@gmail.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 38632@debbugs.gnu.org, yantar92@gmail.com
Subject: bug#38632: 27.0.50; Emacs process name is changed permanently upon creating a named thread
Date: Thu, 19 Dec 2019 17:42:41 +0100 [thread overview]
Message-ID: <m2zhfo9shq.fsf@gmail.com> (raw)
In-Reply-To: <8336dg2vvn.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 19 Dec 2019 17:11:24 +0200")
[-- Attachment #1: Type: text/plain, Size: 1041 bytes --]
>>>>> On Thu, 19 Dec 2019 17:11:24 +0200, Eli Zaretskii <eliz@gnu.org> said:
Eli> We need to truncate the names we store in the thread object (and
Eli> document that).
Eli> I think I'm going to change my mind on that. The complication here is
Eli> that the name should be encoded by ENCODE_SYSTEM before we pass it to
Eli> pthread_setname_np etc., and if the locale-coding-system is not UTF-8
Eli> and not single-byte, we don't really know where a character will end
Eli> after encoding. And encoding one character at a time sounds too
Eli> gross.
Eli> So perhaps we should just truncate the bytes, and leave this to the
Eli> application to make sure the result makes sense, and also disregard
Eli> the difference between list-threads and the thread name as the OS and
Eli> debuggers see it. Doing that will also avoid the complication of
Eli> having the thread name return to the caller different from what the
Eli> caller used.
Hereʼs what it looks like.
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 0001-Use-pthread_setname_np-to-set-thread-name.patch --]
[-- Type: text/x-patch, Size: 2496 bytes --]
From bbb7e7837fcad3bac10aef69a1b331243c2b1c4c Mon Sep 17 00:00:00 2001
From: Robert Pluim <rpluim@gmail.com>
Date: Thu, 19 Dec 2019 17:33:16 +0100
Subject: [PATCH] Use pthread_setname_np to set thread name
* configure.ac: Remove check for sys/prctl.h and prctl, check for
pthread_setname_np instead.
* systhread.c: Remove sys/prctl.h include.
(sys_thread_create) [HAVE_PTHREAD_SETNAME_NP]: Use pthread_setname_np
to set the name of the newly created thread (Bug#38632).
---
configure.ac | 4 ++--
src/systhread.c | 17 +++++++++++------
2 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/configure.ac b/configure.ac
index 3b6a2a6d16..34a2654494 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1767,7 +1767,7 @@ AC_DEFUN
sys/sysinfo.h
coff.h pty.h
sys/resource.h
- sys/utsname.h pwd.h utmp.h util.h sys/prctl.h)
+ sys/utsname.h pwd.h utmp.h util.h)
AC_CACHE_CHECK([for ADDR_NO_RANDOMIZE],
[emacs_cv_personality_addr_no_randomize],
@@ -4180,7 +4180,7 @@ AC_DEFUN
sendto recvfrom getsockname getifaddrs freeifaddrs \
gai_strerror sync \
getpwent endpwent getgrent endgrent \
-cfmakeraw cfsetspeed __executable_start log2 prctl)
+cfmakeraw cfsetspeed __executable_start log2 pthread_setname_np)
LIBS=$OLD_LIBS
dnl No need to check for posix_memalign if aligned_alloc works.
diff --git a/src/systhread.c b/src/systhread.c
index 6f4de536fb..55bde837e3 100644
--- a/src/systhread.c
+++ b/src/systhread.c
@@ -98,10 +98,6 @@ sys_thread_yield (void)
#include <sched.h>
-#ifdef HAVE_SYS_PRCTL_H
-#include <sys/prctl.h>
-#endif
-
void
sys_mutex_init (sys_mutex_t *mutex)
{
@@ -227,9 +223,18 @@ sys_thread_create (sys_thread_t *thread_ptr, const char *name,
if (!pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED))
{
result = pthread_create (thread_ptr, &attr, func, arg) == 0;
-#if defined (HAVE_SYS_PRCTL_H) && defined (HAVE_PRCTL) && defined (PR_SET_NAME)
+#ifdef HAVE_PTHREAD_SETNAME_NP
if (result && name != NULL)
- prctl (PR_SET_NAME, name);
+ {
+ /* We need to truncate here otherwise pthread_setname_np
+ fails to set the name. TASK_COMM_LEN is what the length
+ is called in the Linux kernel headers (Bug#38632). */
+#define TASK_COMM_LEN 16
+ char p_name[TASK_COMM_LEN];
+ strncpy (p_name, name, TASK_COMM_LEN - 1);
+ p_name[TASK_COMM_LEN - 1] = '\0';
+ pthread_setname_np (*thread_ptr, p_name);
+ }
#endif
}
--
2.23.0
next prev parent reply other threads:[~2019-12-19 16:42 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-16 6:42 bug#38632: 27.0.50; Emacs process name is changed permanently upon creating a named thread Ihor Radchenko
2019-12-17 20:05 ` Eli Zaretskii
2019-12-18 9:05 ` Robert Pluim
2019-12-18 15:53 ` Eli Zaretskii
2019-12-18 17:04 ` Robert Pluim
2019-12-18 17:18 ` Eli Zaretskii
2019-12-18 21:30 ` Robert Pluim
2019-12-19 15:11 ` Eli Zaretskii
2019-12-19 16:42 ` Robert Pluim [this message]
2019-12-19 18:56 ` Eli Zaretskii
2019-12-20 19:13 ` Eli Zaretskii
2020-01-06 14:43 ` Robert Pluim
2020-01-06 16:22 ` Eli Zaretskii
2020-01-06 19:50 ` Mattias Engdegård
2020-01-06 21:58 ` Mattias Engdegård
2020-01-06 23:06 ` Robert Pluim
2020-01-07 15:45 ` Eli Zaretskii
2020-01-07 16:46 ` Mattias Engdegård
2020-01-07 17:05 ` Eli Zaretskii
2020-01-07 17:07 ` Eli Zaretskii
2020-01-07 17:19 ` Mattias Engdegård
2020-01-08 18:26 ` Glenn Morris
2020-01-08 18:54 ` Eli Zaretskii
2020-01-08 19:34 ` Glenn Morris
2020-01-08 20:01 ` Eli Zaretskii
2020-01-06 22:21 ` Robert Pluim
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