File 0001-Disable-signal-handler-thread-avoid-duplic... of Package octave

Overview Repositories Revisions Requests Users Attributes Meta

File 0001-Disable-signal-handler-thread-avoid-duplicate-signal.patch of Package octave (Revision db54512e905ec96e61fc4828ffeed132)

Currently displaying revision db54512e905ec96e61fc4828ffeed132 , Show latest

From f80ba25e3df56e390ee0fa0fea17b2ac1748bfcf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20Br=C3=BCns?= <stefan.bruens@rwth-aachen.de>
Date: Mon, 17 Feb 2020 14:12:25 +0100
Subject: [PATCH] Disable signal handler thread, avoid duplicate signal
 handlers

octave::set_signal_handlers installs handlers for a bunch of signals,
while the watcher thread waits for the same signals using sigwait.

As a result, it is unspecified if the signal will be handled in
interrupt context by the thread which installed the handlers, or by
the dedicated thread.

Using sigwait has the side effect of possibly also stealing any signals
from a thread which installs a signal handler later. This is the case
for e.g. QProcess::waitForFinished(), which will likely not receive
a SIGCHLD and run in a timeout. This occurs for the native KDE file
dialog, which will spawn external programs for the CIFS/SAMBA usershare
integration iff a SAMBA server is installed locally.

Note this somewhat reverses the problem for QProcess, as QProcess now
steals the SIGCHLD from octaves main thread, although only for a short
duration until the external process is finished. The latter is solved
with the upcoming Qt 5.15 + Linux 5.3, which no longer relies on
SIGCHLD: https://codereview.qt-project.org/c/qt/qtbase/+/108456/

See also https://bugreports.qt.io/browse/QTBUG-56338

Not using a dedicated signal handler thread removes a source of
indeterminism, and also fixes https://savannah.gnu.org/bugs/?54607
---
 liboctave/wrappers/signal-wrappers.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: octave-6.1.0/liboctave/wrappers/signal-wrappers.c
===================================================================
--- octave-6.1.0.orig/liboctave/wrappers/signal-wrappers.c
+++ octave-6.1.0/liboctave/wrappers/signal-wrappers.c
@@ -709,7 +709,7 @@ signal_watcher (void *arg)
 void
 octave_create_interrupt_watcher_thread (octave_sig_handler *handler)
 {
-#if ! defined (__WIN32__)
+#if 0
   pthread_t sighandler_thread_id;
 
   if (pthread_create (&sighandler_thread_id, 0, signal_watcher, handler))

Places

File 0001-Disable-signal-handler-thread-avoid-duplicate-signal.patch of Package octave (Revision db54512e905ec96e61fc4828ffeed132)

Places