jamulus/src/signalhandler.cpp
2020-05-15 20:05:04 +01:00

185 lines
5.9 KiB
C++
Executable file

/******************************************************************************\
* Copyright (c) 2020
*
* Author(s):
* Peter L Jones
*
******************************************************************************
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option) any later
* version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
******************************************************************************
*
* This code contains some ideas derived from QCtrlSignals
* https://github.com/Skycoder42/QCtrlSignals.git
* - mostly the singleton and emitSignal code, plus some of the structure
* - virtually everything else is common knowledge across SourceForge answers
*
* BSD 3-Clause License
*
* Copyright (c) 2016, Felix Barz
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
\******************************************************************************/
#include "signalhandler.h"
class CSignalHandlerSingleton : public CSignalHandler {
public:
inline CSignalHandlerSingleton() : CSignalHandler() {}
};
Q_GLOBAL_STATIC ( CSignalHandlerSingleton, singleton )
CSignalHandler::CSignalHandler() : pSignalBase ( CSignalBase::withSignalHandler ( this ) ) {}
CSignalHandler::~CSignalHandler() = default;
CSignalHandler* CSignalHandler::getSingletonP() { return singleton; }
bool CSignalHandler::emitSignal ( int sigNum )
{
return QMetaObject::invokeMethod( singleton, "HandledSignal", Qt::QueuedConnection, Q_ARG( int, sigNum ) );
}
#ifndef _WIN32
void CSignalHandler::OnSocketNotify( int socket )
{
int sigNum;
if ( ::read ( socket, &sigNum, sizeof ( int ) ) == sizeof ( int ) )
{
emitSignal ( sigNum );
}
}
#endif
// ----------------------------------------------------------
CSignalBase::CSignalBase ( CSignalHandler* pSignalHandler ) :
pSignalHandler ( pSignalHandler )
{
}
CSignalBase::~CSignalBase() = default;
CSignalBase* CSignalBase::withSignalHandler ( CSignalHandler* pSignalHandler )
{
#ifdef _WIN32
return new CSignalWin ( pSignalHandler );
#else
return new CSignalUnix ( pSignalHandler );
#endif
}
#ifdef _WIN32
CSignalWin::CSignalWin ( CSignalHandler* nPSignalHandler ) :
CSignalBase ( nPSignalHandler ),
lock ( QReadWriteLock::Recursive )
{
SetConsoleCtrlHandler ( signalHandler, true );
}
CSignalWin::~CSignalWin() {
SetConsoleCtrlHandler ( signalHandler, false );
}
QReadWriteLock* CSignalWin::getLock() const
{
return &lock;
}
BOOL WINAPI CSignalWin::signalHandler ( _In_ DWORD )
{
auto self = getSelf<CSignalWin>();
QReadLocker lock ( self->getLock() );
return self->pSignalHandler->emitSignal ( -1 );
}
#else
int CSignalUnix::socketPair[2];
CSignalUnix::CSignalUnix ( CSignalHandler* nPSignalHandler ) :
CSignalBase ( nPSignalHandler )
{
if ( ::socketpair ( AF_UNIX, SOCK_STREAM, 0, socketPair ) == 0 )
{
socketNotifier = new QSocketNotifier ( socketPair[ 1 ], QSocketNotifier::Read );
QObject::connect ( socketNotifier, &QSocketNotifier::activated, nPSignalHandler, &CSignalHandler::OnSocketNotify );
socketNotifier->setEnabled ( true );
setSignalHandled ( SIGUSR1, true );
setSignalHandled ( SIGINT, true );
setSignalHandled ( SIGTERM, true );
}
}
CSignalUnix::~CSignalUnix() {
setSignalHandled ( SIGUSR1, false );
setSignalHandled ( SIGINT, false );
setSignalHandled ( SIGTERM, false );
}
QReadWriteLock* CSignalUnix::getLock() const { return nullptr; }
bool CSignalUnix::setSignalHandled ( int sigNum, bool state )
{
struct sigaction sa;
sigemptyset ( &sa.sa_mask );
if ( state )
{
sa.sa_handler = CSignalUnix::signalHandler;
sa.sa_flags |= SA_RESTART;
}
else
{
sa.sa_handler = SIG_DFL;
}
return ::sigaction ( sigNum, &sa, nullptr ) == 0;
}
void CSignalUnix::signalHandler ( int sigNum )
{
const auto res = ::write ( socketPair[ 0 ], &sigNum, sizeof ( int ) );
Q_UNUSED ( res );
}
#endif