File indexing completed on 2024-05-19 15:27:52

 /*
     This file is part of KGraphViewer.
     Copyright (C) 2010  Gael de Chalendar <kleag@free.fr>
 
     This program is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License as
     published by the Free Software Foundation; either version 2 of
     the License, or (at your option) any later version.
 
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 */
 
 #include "loadagraphthread.h"
 #include "kgraphviewerlib_debug.h"
 
 #include <QDebug>
 
 void LoadAGraphThread::run()
 {
     qCDebug(KGRAPHVIEWERLIB_LOG) << m_dotFileName;
     FILE *fp = fopen(m_dotFileName.toUtf8().data(), "r");
     if (!fp) {
         qCWarning(KGRAPHVIEWERLIB_LOG) << "Failed to open file " << m_dotFileName;
         return;
     }
     m_g = agread(fp, nullptr);
     if (!m_g) {
         qCWarning(KGRAPHVIEWERLIB_LOG) << "Failed to read file, retrying to work around graphviz bug(?)";
         rewind(fp);
         m_g = agread(fp, nullptr);
     }
     if (m_g == nullptr) {
         qCWarning(KGRAPHVIEWERLIB_LOG) << "Failed to read file " << m_dotFileName;
     }
     fclose(fp);
 }
 
 void LoadAGraphThread::loadFile(const QString &dotFileName)
 {
     // FIXME: deadlock possible
     // if thread is still running or queued finished signal of the thread has not
     // yet been delivered so its handler who would release the semaphore,
     // then the semaphore can not be acquired and this will block the (main) thread
     // which called LoadAGraphThread::loadFile().
     // That one though very much might have also been the one which before invoked this
     // method and thus the still running thread or yet-to-be delivered finished signal.
     // But being blocked now, it will not reach its event loop where the queued finished
     // signal of the thread would be processed and delivered, so in the further processing
     // by the signal handler this semaphore would be released
     // -> blocked ourselves without any escape
     sem.acquire();
     m_dotFileName = dotFileName;
     m_g = nullptr;
     start();
 }
 
 #include "moc_loadagraphthread.cpp"