Attachment 43753 Details for Bug 33336 – bus signal_handler: don't use _dbus_warn, and don't pretend to be portable

[patch] bus signal_handler: don't use _dbus_warn, and don't pretend to be portable

0004-bus-signal_handler-don-t-use-_dbus_warn-and-don-t-pr.patch (text/plain), 2.71 KB, created by Simon McVittie on 2011-02-24 06:28:53 UTC

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Creator: Simon McVittie

Created: 2011-02-24 06:28:53 UTC

Size: 2.71 KB

patch

obsolete

>From 351189fce1226f2042c47b8a6f794dc4534b0d52 Mon Sep 17 00:00:00 2001
>From: Simon McVittie <simon.mcvittie@collabora.co.uk>
>Date: Thu, 24 Feb 2011 14:25:13 +0000
>Subject: [PATCH 4/4] bus signal_handler: don't use _dbus_warn, and don't pretend to be portable
>
>_dbus_warn isn't async-signal-safe, so that's out. We can use write()
>instead; it's POSIX but not ISO C, but then again, so are signals.
>Accordingly, guard it with DBUS_UNIX.
>
>dbus-sysdeps-util-win doesn't actually implement _dbus_set_signal_handler
>anyway, so not compiling this code on non-Unix seems more honest.
>---
> bus/main.c |   23 +++++++++++++++++++++--
> 1 files changed, 21 insertions(+), 2 deletions(-)
>
>diff --git a/bus/main.c b/bus/main.c
>index 136d122..907ea08 100644
>--- a/bus/main.c
>+++ b/bus/main.c
>@@ -35,6 +35,9 @@
> #ifdef HAVE_ERRNO_H
> #include <errno.h>
> #endif
>+#ifdef HAVE_UNISTD_H
>+#include <unistd.h>     /* for write() and STDERR_FILENO */
>+#endif
> #include "selinux.h"
> 
> static BusContext *context;
>@@ -45,6 +48,7 @@ static int reload_pipe[2];
> 
> static void close_reload_pipe (DBusWatch **);
> 
>+#ifdef DBUS_UNIX
> static void
> signal_handler (int sig)
> {
>@@ -69,14 +73,24 @@ signal_handler (int sig)
>              * reloaded while draining the pipe buffer, which is what we
>              * wanted. It's harmless that it will be reloaded fewer times than
>              * we asked for, since the reload is delayed anyway, so new changes
>-             * will be picked up. */
>-            _dbus_warn ("Unable to write to reload pipe.\n");
>+             * will be picked up.
>+             *
>+             * We use write() because _dbus_warn uses vfprintf, which isn't
>+             * async-signal-safe.
>+             *
>+             * This is necessarily Unix-specific, but so are POSIX signals,
>+             * so... */
>+            static const char *message =
>+              "Unable to write to reload pipe - buffer full?\n";
>+
>+            write (STDERR_FILENO, message, strlen (message));
>           }
>       }
>       break;
> #endif
>     }
> }
>+#endif /* DBUS_UNIX */
> 
> static void
> usage (void)
>@@ -521,12 +535,17 @@ main (int argc, char **argv)
> 
>   setup_reload_pipe (bus_context_get_loop (context));
> 
>+#ifdef DBUS_UNIX
>+  /* POSIX signals are Unix-specific, and _dbus_set_signal_handler is
>+   * unimplemented (and probably unimplementable) on Windows, so there's
>+   * no point in trying to make the handler portable to non-Unix. */
> #ifdef SIGHUP
>   _dbus_set_signal_handler (SIGHUP, signal_handler);
> #endif
> #ifdef DBUS_BUS_ENABLE_DNOTIFY_ON_LINUX
>   _dbus_set_signal_handler (SIGIO, signal_handler);
> #endif /* DBUS_BUS_ENABLE_DNOTIFY_ON_LINUX */
>+#endif /* DBUS_UNIX */
> 
>   _dbus_verbose ("We are on D-Bus...\n");
>   _dbus_loop_run (bus_context_get_loop (context));
>-- 
>1.7.4.1
>

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Attachments on bug 33336: 42275 | 42276 | 43752 | 43753

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