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authorMathias Gumz <akira at fluxbox dot org>2014-02-18 18:34:35 (GMT)
committerMathias Gumz <akira at fluxbox dot org>2014-02-18 18:34:35 (GMT)
commit43bdf499d56c09a520dc3bc03438dee4092d3d58 (patch)
treefc08fe113eb7c577eb402bf9ffebd8038d4f90da /src/FbTk/SignalHandler.cc
parent3696562aa87c7e68cb8b00b85f0e8d5cf2d199bf (diff)
downloadfluxbox-43bdf499d56c09a520dc3bc03438dee4092d3d58.zip
fluxbox-43bdf499d56c09a520dc3bc03438dee4092d3d58.tar.bz2
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*
Diffstat (limited to 'src/FbTk/SignalHandler.cc')
-rw-r--r--src/FbTk/SignalHandler.cc79
1 files changed, 0 insertions, 79 deletions
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 @@
1// SignalHandler.cc for FbTk - Fluxbox ToolKit
2// Copyright (c) 2002 - 2006 Henrik Kinnunen (fluxgen at fluxbox dot org)
3//
4// Permission is hereby granted, free of charge, to any person obtaining a
5// copy of this software and associated documentation files (the "Software"),
6// to deal in the Software without restriction, including without limitation
7// the rights to use, copy, modify, merge, publish, distribute, sublicense,
8// and/or sell copies of the Software, and to permit persons to whom the
9// Software is furnished to do so, subject to the following conditions:
10//
11// The above copyright notice and this permission notice shall be included in
12// all copies or substantial portions of the Software.
13//
14// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
19// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
20// DEALINGS IN THE SOFTWARE.
21
22#include "SignalHandler.hh"
23
24namespace FbTk {
25
26SignalEventHandler *SignalHandler::s_signal_handler[NSIG];
27
28SignalHandler::SignalHandler() {
29 // clear signal list
30 for (int i=0; i < NSIG; ++i)
31 s_signal_handler[i] = 0;
32}
33
34SignalHandler &SignalHandler::instance() {
35 static SignalHandler singleton;
36 return singleton;
37}
38
39bool SignalHandler::registerHandler(int signum, SignalEventHandler *eh,
40 SignalEventHandler **oldhandler_ret) {
41 // must be less than NSIG
42 if (signum >= NSIG)
43 return false;
44
45 // get old signal handler for this signum
46 if (oldhandler_ret != 0)
47 *oldhandler_ret = s_signal_handler[signum];
48
49#ifdef HAVE_SIGACTION
50 struct sigaction sa;
51 // set callback
52 sa.sa_handler = SignalHandler::handleSignal;
53 sigemptyset (&sa.sa_mask);
54 sa.sa_flags = 0;
55
56 if (sigaction(signum, &sa, 0) == -1)
57 return false;
58#else
59 // Fallback code for Windows and other platforms lacking sigaction.
60 if (signal(signum, &SignalHandler::handleSignal) == SIG_ERR) {
61 return false;
62 }
63#endif
64 s_signal_handler[signum] = eh;
65
66 return true;
67}
68
69void SignalHandler::handleSignal(int signum) {
70 if (signum >= NSIG)
71 return;
72 // make sure we got a handler for this signal
73 if (s_signal_handler[signum] != 0) {
74 s_signal_handler[signum]->handleSignal(signum);
75 }
76}
77
78}
79