From 351189fce1226f2042c47b8a6f794dc4534b0d52 Mon Sep 17 00:00:00 2001 From: Simon McVittie 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 #endif +#ifdef HAVE_UNISTD_H +#include /* 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