diff --git a/linphone-desktop/CMakeLists.txt b/linphone-desktop/CMakeLists.txt
index 06b1b8b01..fc4acde5d 100644
--- a/linphone-desktop/CMakeLists.txt
+++ b/linphone-desktop/CMakeLists.txt
@@ -93,6 +93,7 @@ set(SOURCES
   src/components/sip-addresses/SipAddressesModel.cpp
   src/components/smart-search-bar/SmartSearchBarModel.cpp
   src/components/timeline/TimelineModel.cpp
+  src/externals/single-application/SingleApplication.cpp
   src/main.cpp
 )
 
@@ -123,6 +124,8 @@ set(HEADERS
   src/components/sip-addresses/SipAddressesModel.hpp
   src/components/smart-search-bar/SmartSearchBarModel.hpp
   src/components/timeline/TimelineModel.hpp
+  src/externals/single-application/SingleApplication.hpp
+  src/externals/single-application/SingleApplicationPrivate.hpp
   src/utils.hpp
 )
 
diff --git a/linphone-desktop/src/externals/single-application/SingleApplication.cpp b/linphone-desktop/src/externals/single-application/SingleApplication.cpp
new file mode 100644
index 000000000..465c68747
--- /dev/null
+++ b/linphone-desktop/src/externals/single-application/SingleApplication.cpp
@@ -0,0 +1,452 @@
+// The MIT License (MIT)
+//
+// Copyright (c) Itay Grudev 2015 - 2016
+//
+// 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 <cstdlib>
+
+#include <QtCore/QDir>
+#include <QtCore/QProcess>
+#include <QtCore/QByteArray>
+#include <QtCore/QSemaphore>
+#include <QtCore/QSharedMemory>
+#include <QtCore/QStandardPaths>
+#include <QtCore/QCryptographicHash>
+#include <QtNetwork/QLocalServer>
+#include <QtNetwork/QLocalSocket>
+
+#ifdef Q_OS_UNIX
+  #include <signal.h>
+  #include <unistd.h>
+#endif // ifdef Q_OS_UNIX
+
+#ifdef Q_OS_WIN
+  #include <windows.h>
+  #include <lmcons.h>
+#endif // ifdef Q_OS_WIN
+
+#include "SingleApplication.hpp"
+#include "SingleApplicationPrivate.hpp"
+
+// =============================================================================
+
+static const char NewInstance = 'N';
+static const char SecondaryInstance = 'S';
+static const char Reconnect = 'R';
+static const char InvalidConnection = '\0';
+
+// -----------------------------------------------------------------------------
+
+SingleApplicationPrivate::SingleApplicationPrivate (SingleApplication *q_ptr) : q_ptr(q_ptr) {
+  server = nullptr;
+  socket = nullptr;
+}
+
+SingleApplicationPrivate::~SingleApplicationPrivate () {
+  if (socket != nullptr) {
+    socket->close();
+    delete socket;
+  }
+  memory->lock();
+  InstancesInfo *inst = (InstancesInfo *)memory->data();
+  if (server != nullptr) {
+    server->close();
+    delete server;
+    inst->primary = false;
+  }
+  memory->unlock();
+  delete memory;
+}
+
+void SingleApplicationPrivate::genBlockServerName (int timeout) {
+  QCryptographicHash appData(QCryptographicHash::Sha256);
+  appData.addData("SingleApplication", 17);
+  appData.addData(SingleApplication::app_t::applicationName().toUtf8());
+  appData.addData(SingleApplication::app_t::organizationName().toUtf8());
+  appData.addData(SingleApplication::app_t::organizationDomain().toUtf8());
+
+  if (!(options & SingleApplication::Mode::ExcludeAppVersion)) {
+    appData.addData(SingleApplication::app_t::applicationVersion().toUtf8());
+  }
+
+  if (!(options & SingleApplication::Mode::ExcludeAppPath)) {
+    #ifdef Q_OS_WIN
+      appData.addData(SingleApplication::app_t::applicationFilePath().toLower().toUtf8());
+    #else
+      appData.addData(SingleApplication::app_t::applicationFilePath().toUtf8());
+    #endif // ifdef Q_OS_WIN
+  }
+
+  // User level block requires a user specific data in the hash
+  if (options & SingleApplication::Mode::User) {
+    #ifdef Q_OS_WIN
+      Q_UNUSED(timeout);
+      wchar_t username[UNLEN + 1];
+      // Specifies size of the buffer on input
+      DWORD usernameLength = UNLEN + 1;
+      if (GetUserNameW(username, &usernameLength)) {
+        appData.addData(QString::fromWCharArray(username).toUtf8());
+      } else {
+        appData.addData(QStandardPaths::standardLocations(QStandardPaths::HomeLocation).join("").toUtf8());
+      }
+    #endif // ifdef Q_OS_WIN
+    #ifdef Q_OS_UNIX
+      QProcess process;
+      process.start("whoami");
+      if (process.waitForFinished(timeout) &&
+          process.exitCode() == QProcess::NormalExit) {
+        appData.addData(process.readLine());
+      } else {
+        appData.addData(
+          QDir(
+            QStandardPaths::standardLocations(QStandardPaths::HomeLocation).first()
+          ).absolutePath().toUtf8()
+        );
+      }
+    #endif // ifdef Q_OS_UNIX
+  }
+
+  // Replace the backslash in RFC 2045 Base64 [a-zA-Z0-9+/=] to comply with
+  // server naming requirements.
+  blockServerName = appData.result().toBase64().replace("/", "_");
+}
+
+void SingleApplicationPrivate::startPrimary (bool resetMemory) {
+  #ifdef Q_OS_UNIX
+    // Handle any further termination signals to ensure the
+    // QSharedMemory block is deleted even if the process crashes
+    crashHandler();
+  #endif // ifdef Q_OS_UNIX
+  // Successful creation means that no main process exists
+  // So we start a QLocalServer to listen for connections
+  QLocalServer::removeServer(blockServerName);
+  server = new QLocalServer();
+
+  // Restrict access to the socket according to the
+  // SingleApplication::Mode::User flag on User level or no restrictions
+  if (options & SingleApplication::Mode::User) {
+    server->setSocketOptions(QLocalServer::UserAccessOption);
+  } else {
+    server->setSocketOptions(QLocalServer::WorldAccessOption);
+  }
+
+  server->listen(blockServerName);
+  QObject::connect(
+    server,
+    &QLocalServer::newConnection,
+    this,
+    &SingleApplicationPrivate::slotConnectionEstablished
+  );
+
+  // Reset the number of connections
+  memory->lock();
+  InstancesInfo *inst = (InstancesInfo *)memory->data();
+
+  if (resetMemory) {
+    inst->primary = true;
+    inst->secondary = 0;
+  } else {
+    inst->primary = true;
+  }
+
+  memory->unlock();
+
+  instanceNumber = 0;
+}
+
+void SingleApplicationPrivate::startSecondary () {
+  #ifdef Q_OS_UNIX
+    // Handle any further termination signals to ensure the
+    // QSharedMemory block is deleted even if the process crashes
+    crashHandler();
+  #endif // ifdef Q_OS_UNIX
+}
+
+void SingleApplicationPrivate::connectToPrimary (int msecs, char connectionType) {
+  // Connect to the Local Server of the Primary Instance if not already
+  // connected.
+  if (socket == nullptr) {
+    socket = new QLocalSocket();
+  }
+
+  // If already connected - we are done;
+  if (socket->state() == QLocalSocket::ConnectedState)
+    return;
+
+  // If not connect
+  if (socket->state() == QLocalSocket::UnconnectedState ||
+      socket->state() == QLocalSocket::ClosingState) {
+    socket->connectToServer(blockServerName);
+  }
+
+  // Wait for being connected
+  if (socket->state() == QLocalSocket::ConnectingState) {
+    socket->waitForConnected(msecs);
+  }
+
+  // Initialisation message according to the SingleApplication protocol
+  if (socket->state() == QLocalSocket::ConnectedState) {
+    // Notify the parent that a new instance had been started;
+    QByteArray initMsg = blockServerName.toLatin1();
+
+    initMsg.append(connectionType);
+    initMsg.append((const char *)&instanceNumber, sizeof(quint32));
+    initMsg.append(QByteArray::number(qChecksum(initMsg.constData(), initMsg.length()), 256));
+
+    socket->write(initMsg);
+    socket->flush();
+    socket->waitForBytesWritten(msecs);
+  }
+}
+
+#ifdef Q_OS_UNIX
+  void SingleApplicationPrivate::crashHandler () {
+    // This guarantees the program will work even with multiple
+    // instances of SingleApplication in different threads.
+    // Which in my opinion is idiotic, but lets handle that too.
+    {
+      sharedMemMutex.lock();
+      sharedMem.append(this);
+      sharedMemMutex.unlock();
+    }
+
+    // Handle any further termination signals to ensure the
+    // QSharedMemory block is deleted even if the process crashes
+    signal(SIGHUP, SingleApplicationPrivate::terminate);        // 1
+    signal(SIGINT, SingleApplicationPrivate::terminate);        // 2
+    signal(SIGQUIT, SingleApplicationPrivate::terminate);       // 3
+    signal(SIGILL, SingleApplicationPrivate::terminate);        // 4
+    signal(SIGABRT, SingleApplicationPrivate::terminate);       // 6
+    signal(SIGFPE, SingleApplicationPrivate::terminate);        // 8
+    signal(SIGBUS, SingleApplicationPrivate::terminate);        // 10
+    signal(SIGSEGV, SingleApplicationPrivate::terminate);       // 11
+    signal(SIGSYS, SingleApplicationPrivate::terminate);        // 12
+    signal(SIGPIPE, SingleApplicationPrivate::terminate);       // 13
+    signal(SIGALRM, SingleApplicationPrivate::terminate);       // 14
+    signal(SIGTERM, SingleApplicationPrivate::terminate);       // 15
+    signal(SIGXCPU, SingleApplicationPrivate::terminate);       // 24
+    signal(SIGXFSZ, SingleApplicationPrivate::terminate);       // 25
+  }
+
+  void SingleApplicationPrivate::terminate (int signum) {
+    while (!sharedMem.empty()) {
+      delete sharedMem.back();
+      sharedMem.pop_back();
+    }
+    ::exit(128 + signum);
+  }
+
+  QList<SingleApplicationPrivate *> SingleApplicationPrivate::sharedMem;
+  QMutex SingleApplicationPrivate::sharedMemMutex;
+#endif // ifdef Q_OS_UNIX
+
+/**
+ * @brief Executed when a connection has been made to the LocalServer
+ */
+void SingleApplicationPrivate::slotConnectionEstablished () {
+  Q_Q(SingleApplication);
+
+  QLocalSocket *nextConnSocket = server->nextPendingConnection();
+
+  // Verify that the new connection follows the SingleApplication protocol
+  char connectionType = InvalidConnection;
+  quint32 instanceId;
+  QByteArray initMsg, tmp;
+  if (nextConnSocket->waitForReadyRead(100)) {
+    tmp = nextConnSocket->read(blockServerName.length());
+    // Verify that the socket data start with blockServerName
+    if (tmp == blockServerName.toLatin1()) {
+      initMsg = tmp;
+      connectionType = nextConnSocket->read(1)[0];
+
+      switch (connectionType) {
+        case NewInstance:
+        case SecondaryInstance:
+        case Reconnect: {
+          initMsg += connectionType;
+          tmp = nextConnSocket->read(sizeof(quint32));
+          const char *data = tmp.constData();
+          instanceId = (quint32) * data;
+          initMsg += tmp;
+          // Verify the checksum of the initMsg
+          QByteArray checksum = QByteArray::number(
+              qChecksum(initMsg.constData(), initMsg.length()),
+              256
+            );
+          tmp = nextConnSocket->read(checksum.length());
+          if (checksum == tmp)
+            break;         // Otherwise set to invalid connection (next line)
+        }
+        default:
+          connectionType = InvalidConnection;
+      }
+    }
+  }
+
+  if (connectionType == InvalidConnection) {
+    nextConnSocket->close();
+    delete nextConnSocket;
+    return;
+  }
+
+  QObject::connect(
+    nextConnSocket,
+    &QLocalSocket::aboutToClose,
+    this,
+    [nextConnSocket, instanceId, this]() {
+      Q_EMIT this->slotClientConnectionClosed(nextConnSocket, instanceId);
+    }
+  );
+
+  QObject::connect(
+    nextConnSocket,
+    &QLocalSocket::readyRead,
+    this,
+    [nextConnSocket, instanceId, this]() {
+      Q_EMIT this->slotDataAvailable(nextConnSocket, instanceId);
+    }
+  );
+
+  if (connectionType == NewInstance || (
+        connectionType == SecondaryInstance &&
+        options & SingleApplication::Mode::SecondaryNotification
+      )
+  ) {
+    Q_EMIT q->instanceStarted();
+  }
+
+  if (nextConnSocket->bytesAvailable() > 0) {
+    Q_EMIT this->slotDataAvailable(nextConnSocket, instanceId);
+  }
+}
+
+void SingleApplicationPrivate::slotDataAvailable (QLocalSocket *dataSocket, quint32 instanceId) {
+  Q_Q(SingleApplication);
+  Q_EMIT q->receivedMessage(instanceId, dataSocket->readAll());
+}
+
+void SingleApplicationPrivate::slotClientConnectionClosed (QLocalSocket *closedSocket, quint32 instanceId) {
+  if (closedSocket->bytesAvailable() > 0)
+    Q_EMIT slotDataAvailable(closedSocket, instanceId);
+  closedSocket->deleteLater();
+}
+
+/**
+ * @brief Constructor. Checks and fires up LocalServer or closes the program
+ * if another instance already exists
+ * @param argc
+ * @param argv
+ * @param {bool} allowSecondaryInstances
+ */
+SingleApplication::SingleApplication (int &argc, char *argv[], bool allowSecondary, Options options, int timeout)
+  : app_t(argc, argv), d_ptr(new SingleApplicationPrivate(this)) {
+  Q_D(SingleApplication);
+
+  // Store the current mode of the program
+  d->options = options;
+
+  // Generating an application ID used for identifying the shared memory
+  // block and QLocalServer
+  d->genBlockServerName(timeout);
+
+  // Guarantee thread safe behaviour with a shared memory block. Also by
+  // explicitly attaching it and then deleting it we make sure that the
+  // memory is deleted even if the process had crashed on Unix.
+  #ifdef Q_OS_UNIX
+    d->memory = new QSharedMemory(d->blockServerName);
+    d->memory->attach();
+    delete d->memory;
+  #endif // ifdef Q_OS_UNIX
+  d->memory = new QSharedMemory(d->blockServerName);
+
+  // Create a shared memory block
+  if (d->memory->create(sizeof(InstancesInfo))) {
+    d->startPrimary(true);
+    return;
+  } else {
+    // Attempt to attach to the memory segment
+    if (d->memory->attach()) {
+      d->memory->lock();
+      InstancesInfo *inst = (InstancesInfo *)d->memory->data();
+
+      if (!inst->primary) {
+        d->startPrimary(false);
+        d->memory->unlock();
+        return;
+      }
+
+      // Check if another instance can be started
+      if (allowSecondary) {
+        inst->secondary += 1;
+        d->instanceNumber = inst->secondary;
+        d->startSecondary();
+        if (d->options & Mode::SecondaryNotification) {
+          d->connectToPrimary(timeout, SecondaryInstance);
+        }
+        d->memory->unlock();
+        return;
+      }
+
+      d->memory->unlock();
+    }
+  }
+
+  d->connectToPrimary(timeout, NewInstance);
+  delete d;
+  ::exit(EXIT_SUCCESS);
+}
+
+/**
+ * @brief Destructor
+ */
+SingleApplication::~SingleApplication () {
+  Q_D(SingleApplication);
+  delete d;
+}
+
+bool SingleApplication::isPrimary () {
+  Q_D(SingleApplication);
+  return d->server != nullptr;
+}
+
+bool SingleApplication::isSecondary () {
+  Q_D(SingleApplication);
+  return d->server == nullptr;
+}
+
+quint32 SingleApplication::instanceId () {
+  Q_D(SingleApplication);
+  return d->instanceNumber;
+}
+
+bool SingleApplication::sendMessage (QByteArray message, int timeout) {
+  Q_D(SingleApplication);
+
+  // Nobody to connect to
+  if (isPrimary()) return false;
+
+  // Make sure the socket is connected
+  d->connectToPrimary(timeout, Reconnect);
+
+  d->socket->write(message);
+  bool dataWritten = d->socket->flush();
+  d->socket->waitForBytesWritten(timeout);
+  return dataWritten;
+}
diff --git a/linphone-desktop/src/externals/single-application/SingleApplication.hpp b/linphone-desktop/src/externals/single-application/SingleApplication.hpp
new file mode 100644
index 000000000..23b043d41
--- /dev/null
+++ b/linphone-desktop/src/externals/single-application/SingleApplication.hpp
@@ -0,0 +1,133 @@
+// The MIT License (MIT)
+//
+// Copyright (c) Itay Grudev 2015 - 2016
+//
+// 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.
+
+// See: https://github.com/itay-grudev/SingleApplication/
+
+#ifndef SINGLE_APPLICATION_H
+#define SINGLE_APPLICATION_H
+
+#include <QtCore/QtGlobal>
+#include <QtNetwork/QLocalSocket>
+
+#ifndef QAPPLICATION_CLASS
+  #define QAPPLICATION_CLASS QCoreApplication
+#endif // ifndef QAPPLICATION_CLASS
+
+#include QT_STRINGIFY(QAPPLICATION_CLASS)
+
+// =============================================================================
+
+class SingleApplicationPrivate;
+
+/**
+ * @brief The SingleApplication class handles multipe instances of the same
+ * Application
+ * @see QCoreApplication
+ */
+class SingleApplication : public QAPPLICATION_CLASS {
+  Q_OBJECT
+
+  typedef QAPPLICATION_CLASS app_t;
+
+public:
+  /**
+   * @brief Mode of operation of SingleApplication.
+   * Whether the block should be user-wide or system-wide and whether the
+   * primary instance should be notified when a secondary instance had been
+   * started.
+   * @note Operating system can restrict the shared memory blocks to the same
+   * user, in which case the User/System modes will have no effect and the
+   * block will be user wide.
+   * @enum
+   */
+  enum Mode {
+    User = 1 << 0,
+    System = 1 << 1,
+    SecondaryNotification = 1 << 2,
+    ExcludeAppVersion = 1 << 3,
+    ExcludeAppPath = 1 << 4
+  };
+
+  Q_DECLARE_FLAGS(Options, Mode)
+
+  /**
+   * @brief Intitializes a SingleApplication instance with argc command line
+   * arguments in argv
+   * @arg {int &} argc - Number of arguments in argv
+   * @arg {const char *[]} argv - Supplied command line arguments
+   * @arg {bool} allowSecondary - Whether to start the instance as secondary
+   * if there is already a primary instance.
+   * @arg {Mode} mode - Whether for the SingleApplication block to be applied
+   * User wide or System wide.
+   * @arg {int} timeout - Timeout to wait in miliseconds.
+   * @note argc and argv may be changed as Qt removes arguments that it
+   * recognizes
+   * @note Mode::SecondaryNotification only works if set on both the primary
+   * instance and the secondary instance.
+   * @note The timeout is just a hint for the maximum time of blocking
+   * operations. It does not guarantee that the SingleApplication
+   * initialisation will be completed in given time, though is a good hint.
+   * Usually 4*timeout would be the worst case (fail) scenario.
+   * @see See the corresponding QAPPLICATION_CLASS constructor for reference
+   */
+  explicit SingleApplication (int &argc, char *argv[], bool allowSecondary = false, Options options = Mode::User, int timeout = 100);
+  ~SingleApplication ();
+
+  /**
+   * @brief Returns if the instance is the primary instance
+   * @returns {bool}
+   */
+  bool isPrimary ();
+
+  /**
+   * @brief Returns if the instance is a secondary instance
+   * @returns {bool}
+   */
+  bool isSecondary ();
+
+  /**
+   * @brief Returns a unique identifier for the current instance
+   * @returns {int}
+   */
+  quint32 instanceId ();
+
+  /**
+   * @brief Sends a message to the primary instance. Returns true on success.
+   * @param {int} timeout - Timeout for connecting
+   * @returns {bool}
+   * @note sendMessage() will return false if invoked from the primary
+   * instance.
+   */
+  bool sendMessage (QByteArray message, int timeout = 100);
+
+Q_SIGNALS:
+  void instanceStarted ();
+  void receivedMessage (quint32 instanceId, QByteArray message);
+
+private:
+  SingleApplicationPrivate *d_ptr;
+  Q_DECLARE_PRIVATE(SingleApplication)
+};
+
+Q_DECLARE_OPERATORS_FOR_FLAGS(SingleApplication::Options)
+
+#endif // SINGLE_APPLICATION_H
diff --git a/linphone-desktop/src/externals/single-application/SingleApplicationPrivate.hpp b/linphone-desktop/src/externals/single-application/SingleApplicationPrivate.hpp
new file mode 100644
index 000000000..cc8c8dc50
--- /dev/null
+++ b/linphone-desktop/src/externals/single-application/SingleApplicationPrivate.hpp
@@ -0,0 +1,82 @@
+// The MIT License (MIT)
+//
+// Copyright (c) Itay Grudev 2015 - 2016
+//
+// 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.
+
+//
+// W A R N I N G !!!
+// -----------------
+//
+// This file is not part of the SingleApplication API. It is used purely as an
+// implementation detail. This header file may change from version to
+// version without notice, or may even be removed.
+//
+
+#ifndef SINGLE_APPLICATION_PRIVATE_H
+#define SINGLE_APPLICATION_PRIVATE_H
+
+#include <QtCore/QMutex>
+#include <QtCore/QSharedMemory>
+#include <QtNetwork/QLocalServer>
+#include <QtNetwork/QLocalSocket>
+
+#include "SingleApplication.hpp"
+
+// =============================================================================
+
+struct InstancesInfo {
+  bool primary;
+  quint32 secondary;
+};
+
+class SingleApplicationPrivate : public QObject {
+  Q_OBJECT
+
+public:
+  Q_DECLARE_PUBLIC(SingleApplication) SingleApplicationPrivate (SingleApplication *q_ptr);
+  ~SingleApplicationPrivate ();
+
+  void genBlockServerName (int msecs);
+  void startPrimary (bool resetMemory);
+  void startSecondary ();
+  void connectToPrimary (int msecs, char connectionType);
+
+  #ifdef Q_OS_UNIX
+    void crashHandler ();
+    static void terminate (int signum);
+    static QList<SingleApplicationPrivate *> sharedMem;
+    static QMutex sharedMemMutex;
+  #endif // ifdef Q_OS_UNIX
+
+  QSharedMemory *memory;
+  SingleApplication *q_ptr;
+  QLocalSocket *socket;
+  QLocalServer *server;
+  quint32 instanceNumber;
+  QString blockServerName;
+  SingleApplication::Options options;
+
+public Q_SLOTS:
+  void slotConnectionEstablished ();
+  void slotDataAvailable(QLocalSocket *, quint32);
+  void slotClientConnectionClosed(QLocalSocket *, quint32);
+};
+
+#endif // SINGLE_APPLICATION_PRIVATE_H