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-rw-r--r--singleapplication.cpp429
1 files changed, 59 insertions, 370 deletions
diff --git a/singleapplication.cpp b/singleapplication.cpp
index a333a62..8dd94a8 100644
--- a/singleapplication.cpp
+++ b/singleapplication.cpp
@@ -1,6 +1,6 @@
// The MIT License (MIT)
//
-// Copyright (c) Itay Grudev 2015 - 2016
+// Copyright (c) Itay Grudev 2015 - 2018
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
@@ -20,355 +20,15 @@
// 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/QTime>
+#include <QtCore/QThread>
+#include <QtCore/QDateTime>
#include <QtCore/QByteArray>
-#include <QtCore/QSemaphore>
#include <QtCore/QSharedMemory>
-#include <QtCore/QStandardPaths>
-#include <QtCore/QCryptographicHash>
-#include <QtCore/QDataStream>
-#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"
-
-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 = static_cast<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 = static_cast<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, ConnectionType 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;
- QDataStream writeStream(&initMsg, QIODevice::WriteOnly);
- writeStream.setVersion(QDataStream::Qt_5_6);
- writeStream << blockServerName.toLatin1();
- writeStream << static_cast<quint8>(connectionType);
- writeStream << instanceNumber;
- quint16 checksum = qChecksum(initMsg.constData(), static_cast<quint32>(initMsg.length()));
- writeStream << checksum;
-
- // The header indicates the message length that follows
- QByteArray header;
- QDataStream headerStream(&header, QIODevice::WriteOnly);
- headerStream.setVersion(QDataStream::Qt_5_6);
- headerStream << (quint64) initMsg.length();
-
- socket->write( header );
- socket->write( initMsg );
- socket->flush();
- socket->waitForBytesWritten( msecs );
- }
-}
-
-qint64 SingleApplicationPrivate::primaryPid()
-{
- qint64 pid;
-
- memory->lock();
- InstancesInfo* inst = static_cast<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();
-
- quint32 instanceId = 0;
- ConnectionType connectionType = InvalidConnection;
- if( nextConnSocket->waitForReadyRead( 100 ) ) {
- // read the fields in same order and format as written
- QDataStream headerStream(nextConnSocket);
- headerStream.setVersion(QDataStream::Qt_5_6);
-
- // Read the header to know the message length
- quint64 msgLen = 0;
- headerStream >> msgLen;
-
- if (msgLen >= sizeof(quint16)) {
- // Read the message body
- QByteArray msgBytes = nextConnSocket->read(msgLen);
- QDataStream readStream(msgBytes);
- readStream.setVersion(QDataStream::Qt_5_6);
-
- // server name
- QByteArray latin1Name;
- readStream >> latin1Name;
-
- // connection type
- quint8 connType = InvalidConnection;
- readStream >> connType;
- connectionType = static_cast<ConnectionType>(connType);
-
- // instance id
- readStream >> instanceId;
-
- // checksum
- quint16 msgChecksum = 0;
- readStream >> msgChecksum;
-
- const quint16 actualChecksum = qChecksum(msgBytes.constData(), static_cast<quint32>(msgBytes.length() - sizeof(quint16)));
-
- if (readStream.status() != QDataStream::Ok || QLatin1String(latin1Name) != blockServerName || msgChecksum != actualChecksum) {
- 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
@@ -386,52 +46,81 @@ SingleApplication::SingleApplication( int &argc, char *argv[], bool allowSeconda
// Generating an application ID used for identifying the shared memory
// block and QLocalServer
- d->genBlockServerName( timeout );
+ d->genBlockServerName();
- // 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
+ // By explicitly attaching it and then deleting it we make sure that the
+ // memory is deleted even after the process has crashed on Unix.
d->memory = new QSharedMemory( d->blockServerName );
d->memory->attach();
delete d->memory;
#endif
+ // Guarantee thread safe behaviour with a shared memory block.
d->memory = new QSharedMemory( d->blockServerName );
// Create a shared memory block
if( d->memory->create( sizeof( InstancesInfo ) ) ) {
- d->startPrimary( true );
- return;
+ // Initialize the shared memory block
+ d->memory->lock();
+ d->initializeMemoryBlock();
+ d->memory->unlock();
} else {
// Attempt to attach to the memory segment
- if( d->memory->attach() ) {
- d->memory->lock();
- InstancesInfo* inst = static_cast<InstancesInfo*>(d->memory->data());
+ if( ! d->memory->attach() ) {
+ qCritical() << "SingleApplication: Unable to attach to shared memory block.";
+ qCritical() << d->memory->errorString();
+ delete d;
+ ::exit( EXIT_FAILURE );
+ }
+ }
+
+ InstancesInfo* inst = static_cast<InstancesInfo*>( d->memory->data() );
+ QTime time;
+ time.start();
+
+ // Make sure the shared memory block is initialised and in consistent state
+ while( true ) {
+ d->memory->lock();
+
+ if( d->blockChecksum() == inst->checksum ) break;
+
+ if( time.elapsed() > 5000 ) {
+ qWarning() << "SingleApplication: Shared memory block has been in an inconsistent state from more than 5s. Assuming primary instance failure.";
+ d->initializeMemoryBlock();
+ }
- if( ! inst->primary ) {
- d->startPrimary( false );
- d->memory->unlock();
- return;
- }
+ d->memory->unlock();
- // 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, SingleApplicationPrivate::SecondaryInstance );
- }
- d->memory->unlock();
- return;
- }
+ // Random sleep here limits the probability of a colision between two racing apps
+ qsrand( QDateTime::currentMSecsSinceEpoch() % std::numeric_limits<uint>::max() );
+ QThread::sleep( 8 + static_cast <unsigned long>( static_cast <float>( qrand() ) / RAND_MAX * 10 ) );
+ }
+
+ if( inst->primary == false) {
+ d->startPrimary();
+ d->memory->unlock();
+ return;
+ }
- d->memory->unlock();
+ // Check if another instance can be started
+ if( allowSecondary ) {
+ inst->secondary += 1;
+ inst->checksum = d->blockChecksum();
+ d->instanceNumber = inst->secondary;
+ d->startSecondary();
+ if( d->options & Mode::SecondaryNotification ) {
+ d->connectToPrimary( timeout, SingleApplicationPrivate::SecondaryInstance );
}
+ d->memory->unlock();
+ return;
}
+ d->memory->unlock();
+
d->connectToPrimary( timeout, SingleApplicationPrivate::NewInstance );
+
delete d;
+
::exit( EXIT_SUCCESS );
}
generated by cgit v1.2.1 (git 2.18.0) at 2024-06-01 20:13:09 +0000