SingleApplication/singleapplication.cpp
Itay Grudev 4f03651072 Primary PID support (#36)
* Added the ability to bring the primary application window to the foreground on Windows systems by adding an option flag. THis option can only be used in Windows development and in applications derived from QApplication with a QMainWindow object.
Because the primary application needs to be instructed to go to the foreground, the option SecondaryNotification must also be set to use this functionality

* Changed the ability to bring the primary application window to the front as discussed in itay-grudev/SingleApplication#31.

Now the process ID of the primary application get stored and is accessible for other instances of the application. It is to the developer to bring the applications windows to the front. For convenience the accompanying readme now contains a paragraph with example of how to do this on Windows systems.

* v3.0.9 Added SingleApplicationPrivate::primaryPid()
2017-10-02 12:17:41 +01:00

475 lines
15 KiB
C++

// 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_WIN
#include <windows.h>
#include <lmcons.h>
#endif
#include "singleapplication.h"
#include "singleapplication_p.h"
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;
inst->primaryPid = -1;
}
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
}
// 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_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
}
// 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 )
{
Q_Q(SingleApplication);
#ifdef Q_OS_UNIX
// Handle any further termination signals to ensure the
// QSharedMemory block is deleted even if the process crashes
crashHandler();
#endif
// 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->secondary = 0;
}
inst->primary = true;
inst->primaryPid = q->applicationPid();
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
}
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 );
}
}
qint64 SingleApplicationPrivate::primaryPid()
{
qint64 pid;
memory->lock();
InstancesInfo* inst = (InstancesInfo*)memory->data();
pid = inst->primaryPid;
memory->unlock();
return pid;
}
#ifdef Q_OS_UNIX
void SingleApplicationPrivate::crashHandler()
{
// 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 )
{
delete ((SingleApplication*)QCoreApplication::instance())->d_ptr;
::exit( 128 + signum );
}
#endif
/**
* @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
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;
}
qint64 SingleApplication::primaryPid()
{
Q_D(SingleApplication);
return d->primaryPid();
}
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;
}