src/app/applicationinstancemanager.cpp

   1 /*
   2  * Bittorrent Client using Qt and libtorrent.
   3  * Copyright (C) 2019  Vladimir Golovnev <glassez@yandex.ru>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  *
  19  * In addition, as a special exception, the copyright holders give permission to
  20  * link this program with the OpenSSL project's "OpenSSL" library (or with
  21  * modified versions of it that use the same license as the "OpenSSL" library),
  22  * and distribute the linked executables. You must obey the GNU General Public
  23  * License in all respects for all of the code used other than "OpenSSL".  If you
  24  * modify file(s), you may extend this exception to your version of the file(s),
  25  * but you are not obligated to do so. If you do not wish to do so, delete this
  26  * exception statement from your version.
  27  */
  28
  29 #include "applicationinstancemanager.h"
  30
  31 #include <QtSystemDetection>
  32
  33 #ifdef Q_OS_WIN
  34 #include <windows.h>
  35
  36 #include <QDebug>
  37 #include <QSharedMemory>
  38 #endif
  39
  40 #include "base/path.h"
  41 #include "qtlocalpeer/qtlocalpeer.h"
  42
  43 ApplicationInstanceManager::ApplicationInstanceManager(const Path &instancePath, QObject *parent)
  44     : QObject {parent}
  45     , m_peer {new QtLocalPeer(instancePath.data(), this)}
  46     , m_isFirstInstance {!m_peer->isClient()}
  47 {
  48     connect(m_peer, &QtLocalPeer::messageReceived, this, &ApplicationInstanceManager::messageReceived);
  49
  50 #ifdef Q_OS_WIN
  51     const QString sharedMemoryKey = instancePath.data() + u"/shared-memory";
  52     auto sharedMem = new QSharedMemory(sharedMemoryKey, this);
  53     if (m_isFirstInstance)
  54     {
  55         // First instance creates shared memory and store PID
  56         if (sharedMem->create(sizeof(DWORD)) && sharedMem->lock())
  57         {
  58             *(static_cast<DWORD *>(sharedMem->data())) = ::GetCurrentProcessId();
  59             sharedMem->unlock();
  60         }
  61     }
  62     else
  63     {
  64         // Later instances attach to shared memory and retrieve PID
  65         if (sharedMem->attach() && sharedMem->lock())
  66         {
  67             ::AllowSetForegroundWindow(*(static_cast<DWORD *>(sharedMem->data())));
  68             sharedMem->unlock();
  69         }
  70     }
  71
  72     if (!sharedMem->isAttached())
  73         qCritical() << "Failed to initialize shared memory: " << sharedMem->errorString();
  74 #endif
  75 }
  76
  77 bool ApplicationInstanceManager::isFirstInstance() const
  78 {
  79     return m_isFirstInstance;
  80 }
  81
  82 bool ApplicationInstanceManager::sendMessage(const QString &message, const int timeout)
  83 {
  84     return m_peer->sendMessage(message, timeout);
  85 }