Reworked logger to better handle multithreading

sleepyhead/main.cpp

@@ -25,6 +25,8 @@
 #include <QSettings>
 #include <QFileDialog>
 #include <QSysInfo>
+#include <QThreadPool>
+
 
 #include "SleepLib/schema.h"
 #include "mainwindow.h"
@@ -50,18 +52,19 @@
 
 MainWindow *mainwin = nullptr;
 
+QMutex mutex;
+
 #if QT_VERSION < QT_VERSION_CHECK(5,0,0)
 void MyOutputHandler(QtMsgType type, const char *msgtxt)
 {
+
 #else
 void MyOutputHandler(QtMsgType type, const QMessageLogContext &context, const QString &msgtxt)
 {
     Q_UNUSED(context)
 #endif
 
-    if (!mainwin) {
-        //  qInstallMessageHandler(0);
-
+    if (!logger) {
 #if QT_VERSION >= QT_VERSION_CHECK(5,0,0)
         fprintf(stderr, "Pre/Post: %s\n", msgtxt.toLocal8Bit().constData());
 #else
@@ -96,13 +99,16 @@ void MyOutputHandler(QtMsgType type, const QMessageLogContext &context, const QS
 #else
     msg = typestr + msgtxt;
 #endif
-    mainwin->Log(msg);
+
+    if (logger && logger->isRunning()) logger->append(msg);
+    else {
+        fprintf(stderr, msg.toLocal8Bit().data());
+    }
 
     if (type == QtFatalMsg) {
         abort();
     }
 
-    //loglock.unlock();
 }
 
 void initialize()
@@ -173,6 +179,23 @@ int main(int argc, char *argv[])
         }
     }
 
+    logger = new LogThread();
+    QThreadPool * threadpool = QThreadPool::globalInstance();
+    bool b = threadpool->tryStart(logger);
+    if (b) {
+        qWarning() << "Started logging thread";
+    } else {
+        qWarning() << "Logging thread did not start correctly";
+    }
+
+#if QT_VERSION >= QT_VERSION_CHECK(5,0,0)
+    qInstallMessageHandler(MyOutputHandler);
+#else
+    qInstallMsgHandler(MyOutputHandler);
+#endif
+
+
+
     ////////////////////////////////////////////////////////////////////////////////////////////
     // Language Selection
     ////////////////////////////////////////////////////////////////////////////////////////////
@@ -430,18 +453,12 @@ retry_directory:
 
     qDebug() << "Selected Font" << QApplication::font().family();
 
-#if QT_VERSION >= QT_VERSION_CHECK(5,0,0)
-    qInstallMessageHandler(MyOutputHandler);
-#else
-    qInstallMsgHandler(MyOutputHandler);
-#endif
-
     // Must be initialized AFTER profile creation
     MainWindow w;
 
     mainwin = &w;
 
-    if (check_updates) { mainwin->CheckForUpdates(); }
+  //  if (check_updates) { mainwin->CheckForUpdates(); }
 
     w.show();
 

sleepyhead/mainwindow.cpp

@@ -33,6 +33,8 @@
 #include <QTranslator>
 #include <QPushButton>
 #include <QCalendarWidget>
+#include <QThreadPool>
+
 #include "common_gui.h"
 
 #include <cmath>
@@ -114,31 +116,47 @@ QString getGraphicsEngine()
     return gfxEngine;
 }
 
-void MainWindow::Log(QString s)
+LogThread * logger = nullptr;
+
+void LogThread::append(QString msg)
 {
-
-    if (!strlock.tryLock()) {
-        return;
-    }
-
-    //  strlock.lock();
-    QString tmp = QString("%1: %2").arg(logtime.elapsed(), 5, 10, QChar('0')).arg(s);
-
-    logbuffer.append(tmp); //QStringList appears not to be threadsafe
-    strlock.unlock();
-
+    QString tmp = QString("%1: %2").arg(logtime.elapsed(), 5, 10, QChar('0')).arg(msg);
+    //QStringList appears not to be threadsafe
     strlock.lock();
-
-    // only do this in the main thread?
-    for (int i = 0; i < logbuffer.size(); i++) {
-        ui->logText->appendPlainText(logbuffer[i]);
-        fprintf(stderr, "%s\n", logbuffer[i].toLocal8Bit().constData());
-    }
-
-    logbuffer.clear();
+    buffer.append(tmp);
     strlock.unlock();
+}
 
-    //loglock.unlock();
+void LogThread::quit() {
+    qDebug() << "Shutting down logging thread";
+    running = false;
+    strlock.lock();
+    while (!buffer.isEmpty()) {
+        QString msg = buffer.takeFirst();
+        fprintf(stderr, "%s\n", msg.toLocal8Bit().constData());
+    }
+    strlock.unlock();
+}
+
+
+void LogThread::run()
+{
+    running = true;
+    do {
+        strlock.lock();
+        while (!buffer.isEmpty()) {
+            QString msg = buffer.takeFirst();
+            emit outputLog(msg);
+            fprintf(stderr, "%s\n", msg.toLocal8Bit().constData());
+        }
+        strlock.unlock();
+        QThread::msleep(1000);
+    } while (running);
+}
+
+void MainWindow::logMessage(QString msg)
+{
+    ui->logText->appendPlainText(msg);
 }
 
 MainWindow::MainWindow(QWidget *parent) :
@@ -147,9 +165,12 @@ MainWindow::MainWindow(QWidget *parent) :
 {
     Q_ASSERT(p_profile != nullptr);
 
-    logtime.start();
     ui->setupUi(this);
 
+    if (logger) {
+        connect(logger, SIGNAL(outputLog(QString)), this, SLOT(logMessage(QString)));
+    }
+
     QString version = VersionString;
 
 #ifdef TEST_BUILD
@@ -164,6 +185,14 @@ MainWindow::MainWindow(QWidget *parent) :
 
 
     this->setWindowTitle(STR_TR_SleepyHead + QString(" v%1 (" + tr("Profile") + ": %2)").arg(version).arg(PREF[STR_GEN_Profile].toString()));
+
+    qDebug() << STR_TR_SleepyHeadVersion.toLocal8Bit().data() << "built with Qt" << QT_VERSION_STR <<
+             "on" << __DATE__ << __TIME__;
+
+#ifdef BROKEN_OPENGL_BUILD
+    qDebug() << "This build has been created especially for computers with older graphics hardware.\n";
+#endif
+
     //ui->tabWidget->setCurrentIndex(1);
 
 #ifdef Q_OS_MAC
@@ -315,27 +344,28 @@ MainWindow::MainWindow(QWidget *parent) :
 
 void MainWindow::closeEvent(QCloseEvent * event)
 {
+    // Shutdown and Save the current User profile
+    Profiles::Done();
+
     if (daily) {
-        daily->close();
+        //daily->close();
         daily->deleteLater();
     }
 
     if (overview) {
-        overview->close();
+        //overview->close();
         overview->deleteLater();
     }
 
     if (oximetry) {
-        oximetry->close();
+        //oximetry->close();
         oximetry->deleteLater();
     }
 
-    // Shutdown and Save the current User profile
-    Profiles::Done();
-
     // Save current window position
     QSettings settings(getDeveloperName(), getAppName());
     settings.setValue("MainWindow/geometry", saveGeometry());
+
     QMainWindow::closeEvent(event);
 }
 
@@ -349,6 +379,12 @@ MainWindow::~MainWindow()
     // Trash anything allocated by the Graph objects
     DestroyGraphGlobals();
 
+    logger->quit();
+    disconnect(logger, SIGNAL(outputLog(QString)), this, SLOT(logMessage(QString)));
+
+    QThreadPool::globalInstance()->waitForDone(-1);
+    logger = nullptr;
+
     mainwin = nullptr;
     delete ui;
 }
@@ -400,13 +436,6 @@ void MainWindow::PopulatePurgeMenu()
 
 void MainWindow::Startup()
 {
-    qDebug() << STR_TR_SleepyHeadVersion.toLocal8Bit().data() << "built with Qt" << QT_VERSION_STR <<
-             "on" << __DATE__ << __TIME__;
-
-#ifdef BROKEN_OPENGL_BUILD
-    qDebug() << "This build has been created especially for computers with older graphics hardware.\n";
-#endif
-
     qstatus->setText(tr("Loading Data"));
     qprogress->show();
     //qstatusbar->showMessage(tr("Loading Data"),0);
@@ -1219,11 +1248,14 @@ void MainWindow::on_actionDebug_toggled(bool checked)
 {
     PROFILE.general->setShowDebug(checked);
 
+    logger->strlock.lock();
     if (checked) {
         ui->logText->show();
     } else {
         ui->logText->hide();
     }
+  //  QApplication::processEvents();
+    logger->strlock.unlock();
 }
 
 void MainWindow::on_action_Reset_Graph_Layout_triggered()

sleepyhead/mainwindow.h

@@ -17,6 +17,8 @@
 #include <QNetworkAccessManager>
 #include <QNetworkReply>
 #include <QSystemTrayIcon>
+#include <QRunnable>
+#include <QPlainTextEdit>
 
 #include "version.h"
 #include "daily.h"
@@ -65,6 +67,30 @@ class Daily;
 class Report;
 class Overview;
 
+class LogThread:public QObject, public QRunnable
+{
+    Q_OBJECT
+public:
+    explicit LogThread() { running = false; logtime.start(); }
+    virtual ~LogThread() {}
+
+    void run();
+    void append(QString msg);
+    bool isRunning() { return running; }
+
+    void quit();
+
+    QStringList buffer;
+    QMutex strlock;
+signals:
+    void outputLog(QString);
+protected:
+    volatile bool running;
+    QTime logtime;
+};
+extern LogThread * logger;
+
+
 /*! \class MainWindow
     \author Mark Watkins
     \brief The Main Application window for SleepyHead
@@ -78,9 +104,6 @@ class MainWindow : public QMainWindow
     explicit MainWindow(QWidget *parent = 0);
     ~MainWindow();
 
-    //! \brief Log message s to Application Debug log
-    void Log(QString s);
-
     //! \brief Update the list of Favourites (Bookmarks) in the right sidebar.
     void updateFavourites();
 
@@ -314,6 +337,8 @@ class MainWindow : public QMainWindow
 
     void on_actionPurgeCurrentDaysOximetry_triggered();
 
+    void logMessage(QString msg);
+
 private:
     int importCPAP(const QString &path, const QString &message);
     void importCPAPBackups();
@@ -329,8 +354,6 @@ private:
     Oximetry *oximetry;
     bool first_load;
     PreferencesDialog *prefdialog;
-    QMutex loglock, strlock;
-    QStringList logbuffer;
     QTime logtime;
     QSystemTrayIcon *systray;
     QMenu *systraymenu;
@@ -343,8 +366,6 @@ private:
 
     //! \brief Destroy ALL the CPAP data for the selected machine
     void purgeMachine(Machine *);
-
-
 };
 
 #endif // MAINWINDOW_H