Replace qetsingleapplication by singleApplication.

See : https://github.com/itay-grudev/SingleApplication


git-svn-id: svn+ssh://svn.tuxfamily.org/svnroot/qet/qet/trunk@5481 bfdf4180-ca20-0410-9c96-a3a8aa849046

SingleApplication/singleapplication.cpp

@@ -0,0 +1,174 @@
+// The MIT License (MIT)
+//
+// 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
+// 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 <QtCore/QTime>
+#include <QtCore/QThread>
+#include <QtCore/QDateTime>
+#include <QtCore/QByteArray>
+#include <QtCore/QSharedMemory>
+
+#include "singleapplication.h"
+#include "singleapplication_p.h"
+
+/**
+ * @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();
+
+#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 ) ) ) {
+        // 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() ) {
+            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();
+        }
+
+        d->memory->unlock();
+
+        // 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;
+    }
+
+    // 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 );
+}
+
+/**
+ * @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,  SingleApplicationPrivate::Reconnect );
+
+    d->socket->write( message );
+    bool dataWritten = d->socket->flush();
+    d->socket->waitForBytesWritten( timeout );
+    return dataWritten;
+}