QProcess not exiting when invoked from a QThread

bemineni

0 down vote favorite

I am trying to install a RPM using QProcess(/bin/rpm). This QProcess is running in a concurrent thread which was started by another QThread.

   @QThread retThread = new CMyThread(this);
   connect(retThread, SIGNAL(finished()), retThread, SLOT(deleteLater()));
   retThread->start();@

For some reason the QProcess keeps on running and never exits. When I get the pid of the QProcess and check using the ps command, I dont' see any rpm command that is being executed. The standard out and standard error both are merged on to a single channel and logged on to a file.

The log indicates that the rpm command has finished the process of the installation.

The same behavior is not seen when I run the rpm installation using the QProcess on the main thread. Is this anything related to the event loop. If so how to check if the event loop exists . As per to my knowledge a thread should automatically create the event loop from QT 4.4 and above. I am using QT 4.8

http://qt-project.org/wiki/Threads_Events_QObjects

I feel like the event loop exists, since I am getting other thread queued signals in this thread.

@QString ORIGINAL_LOG_FILE = "/var/Component.log";

int PROC_WAIT_TIME= 90000;
QSharedPointer<QProcess>  process(new QProcess);


QString program = "/bin/rpm";
QStringList compArgs;

compArgs << "-Uvh"<<"--nodeps"<<"some.rpm";


QStringList configEnvironmentVars = process->systemEnvironment();


process->setEnvironment(configEnvironmentVars);

process->setWorkingDirectory("/tmp/something");

connect(process.data() , SIGNAL(finished(int,QProcess::ExitStatus)),this,SLOT(slot_finished(int,QProcess::ExitStatus)) );

// process->setWorkingDirectory();
process->setProcessChannelMode(QProcess::MergedChannels);
process->setStandardOutputFile&#40;ORIGINAL_LOG_FILE, QIODevice::ReadWrite | QIODevice::Append | QIODevice::Text&#41;;
process->start(program, compArgs);

if (process->waitForStarted())
{
  LOGINFO(m_nodeLogFile,QString("Waiting for the process to finish"));
  do
  {
     LOGINFO(m_nodeLogFile, QString("pid = %1").arg((uint)process->pid()));
     LOGINFO(m_nodeLogFile , QString("Error = %1").arg(process->error()));
     LOGINFO(m_nodeLogFile,QString("Envirnoment variables = %1").arg(configEnvironmentVars.join("\n")));
     LOGINFO(m_nodeLogFile,QString("Working directory = %1").arg(process->workingDirectory()));
     LOGINFO(m_nodeLogFile,QString("State = %1").arg(process->state()));
  }while(!process->waitForFinished(100));@

AcerExtensa

First of all: looks like your Thread construction is wrong. Read this: "How To Really, Truly Use QThreads; The Full Explanation":http://mayaposch.wordpress.com/2011/11/01/how-to-really-truly-use-qthreads-the-full-explanation/

And why are you waiting for process finishing in a loop? Using signal/slots are better approach....