Fix race condition on shutdown

This commit fixes primarily a race condition that occurs when xinit(1) shuts
down: by not acting properly fluxbox gets caught in an infinite loop. It
caused bug #1100.

xinit(1) sends a SIGHUP signal to all processes. fluxbox tries to shutdown
itself properly by shutting down workspaces and screens. While doing that, the
Xserver might be gone already. Additionally, fluxbox used to restart() itself
on SIGHUP, which is clearly not the right thing to do when xinit(1) is about
to end the session.

So, fluxbox does this:

* handling SIGHUP now shuts down fluxbox without clearing workspaces and
  screens.

* A 2 second alarm() is triggered in Fluxbox::shutdown() as a last resort

* XSetIOErrorHandler() is used to recognize the disconnect from the xserver.

* SIGUSR1 is for restarting fluxbox, SIGUSR2 for reloading the config

* FbTk/SignalHandler.cc/hh is gone; this unused abstraction served currently
  no real purpose. Signal handling is now done in main.cc

* Unrelated to the issue itself src/main.cc was trimmed down quite a bit and
  the code (responsible for handling the command line interface) was moved to
  src/cli*

3 files changed, 1 insertions, 146 deletions

diff --git a/src/FbTk/Makefile.am b/src/FbTk/Makefile.am
index d54eaae..610859c 100644
--- a/src/FbTk/Makefile.am
+++ b/src/FbTk/Makefile.am
@@ -33,7 +33,7 @@ libFbTk_a_SOURCES = App.hh App.cc \
         MultiButtonMenuItem.hh MultiButtonMenuItem.cc \
         MenuTheme.hh MenuTheme.cc NotCopyable.hh \
         BorderTheme.hh BorderTheme.cc TextTheme.hh TextTheme.cc \
-        RefCount.hh SimpleCommand.hh SignalHandler.cc SignalHandler.hh \
+        RefCount.hh SimpleCommand.hh \
         TextUtils.hh TextUtils.cc Orientation.hh \
         Texture.cc Texture.hh TextureRender.hh TextureRender.cc \
         Shape.hh Shape.cc \
diff --git a/src/FbTk/SignalHandler.cc b/src/FbTk/SignalHandler.cc
deleted file mode 100644
index 5f06210..0000000
--- a/src/FbTk/SignalHandler.cc
+++ /dev/null
@@ -1,79 +0,0 @@
-// SignalHandler.cc for FbTk - Fluxbox ToolKit
-// Copyright (c) 2002 - 2006 Henrik Kinnunen (fluxgen at fluxbox dot org)
-//
-// Permission is hereby granted, free of charge, to any person obtaining a
-// copy of this software and associated documentation files (the "Software"),
-// to deal in the Software without restriction, including without limitation
-// the rights to use, copy, modify, merge, publish, distribute, sublicense,
-// and/or sell copies of the Software, and to permit persons to whom the
-// Software is furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
-// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
-
-#include "SignalHandler.hh"
-
-namespace FbTk {
-
-SignalEventHandler *SignalHandler::s_signal_handler[NSIG];
-
-SignalHandler::SignalHandler() {
-    // clear signal list
-    for (int i=0; i < NSIG; ++i)
-        s_signal_handler[i] = 0;
-}
-
-SignalHandler &SignalHandler::instance() {
-    static SignalHandler singleton;
-    return singleton;
-}
-
-bool SignalHandler::registerHandler(int signum, SignalEventHandler *eh,
-                                    SignalEventHandler **oldhandler_ret) {
-    // must be less than NSIG
-    if (signum >= NSIG)
-        return false;
-
-    // get old signal handler for this signum
-    if (oldhandler_ret != 0)
-        *oldhandler_ret = s_signal_handler[signum];
-
-#ifdef HAVE_SIGACTION
-    struct sigaction sa;
-    // set callback
-    sa.sa_handler = SignalHandler::handleSignal;
-    sigemptyset (&sa.sa_mask);
-    sa.sa_flags = 0;
-
-    if (sigaction(signum, &sa, 0) == -1)
-        return false;
-#else
-    // Fallback code for Windows and other platforms lacking sigaction.
-    if (signal(signum, &SignalHandler::handleSignal) == SIG_ERR) {
-        return false;
-    }
-#endif
-    s_signal_handler[signum] = eh;
-
-    return true;
-}
-
-void SignalHandler::handleSignal(int signum) {
-    if (signum >= NSIG)
-        return;
-    // make sure we got a handler for this signal
-    if (s_signal_handler[signum] != 0) {
-        s_signal_handler[signum]->handleSignal(signum);
-    }
-}
-
-}
-
diff --git a/src/FbTk/SignalHandler.hh b/src/FbTk/SignalHandler.hh
deleted file mode 100644
index 774f4b1..0000000
--- a/src/FbTk/SignalHandler.hh
+++ /dev/null
@@ -1,66 +0,0 @@
-// SignalHandler.hh for FbTk
-// Copyright (c) 2002 - 2003 Henrik Kinnunen (fluxgen at fluxbox dot org)
-//
-// Permission is hereby granted, free of charge, to any person obtaining a
-// copy of this software and associated documentation files (the "Software"),
-// to deal in the Software without restriction, including without limitation
-// the rights to use, copy, modify, merge, publish, distribute, sublicense,
-// and/or sell copies of the Software, and to permit persons to whom the
-// Software is furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
-// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
-
-#ifndef FBTK_SIGNALHANDLER_HH
-#define FBTK_SIGNALHANDLER_HH
-
-#include <signal.h>
-
-namespace FbTk {
-
-/// Base class that SignalHandler calls when it gets a signal
-/// Use this to catch system signals
-class SignalEventHandler {
-public:
-    virtual void handleSignal(int signum) = 0;
-    virtual ~SignalEventHandler() { }
-};
-
-///   Handles system signals, singleton.
-/**
-   Usage: inherit the class SignalEventHandler and then register 
-   it to SignalHandler by calling registerHandler with
-   a signal number
-*/
-class SignalHandler {
-public:
-    /// get singleton object
-    static SignalHandler &instance();
-    /** 
-        Register an event handler
-        @return true on success else false
-        @param signum signal number
-        @param eh event handler
-        @param oldhandler_ret return handler to old sighandler
-    */
-    bool registerHandler(int signum, SignalEventHandler *eh, SignalEventHandler **oldhandler_ret = 0);
-
-private:
-    SignalHandler();
-
-    static void handleSignal(int signum);
-
-    static SignalEventHandler *s_signal_handler[NSIG]; ///< NSIG defined in signal.h
-}; 
-
-} // end namespace FbTk
-
-#endif // FBTK_SIGNALHANDLER_HH