[GUI] Settings information, fix missing initial masternodes count value.

src/qt/clientmodel.cpp

@@ -83,6 +83,17 @@ QString ClientModel::getMasternodeCountString() const
     return tr("Total: %1 (IPv4: %2 / IPv6: %3 / Tor: %4 / Unknown: %5)").arg(QString::number(total)).arg(QString::number((int)ipv4)).arg(QString::number((int)ipv6)).arg(QString::number((int)onion)).arg(QString::number((int)nUnknown));
 }
 
+QString ClientModel::getMasternodesCount()
+{
+    if (!cachedMasternodeCountString.isEmpty()) {
+        return cachedMasternodeCountString;
+    }
+
+    // Force an update
+    cachedMasternodeCountString = getMasternodeCountString();
+    return cachedMasternodeCountString;
+}
+
 int ClientModel::getNumBlocks()
 {
     if (!cacheTip) {
@@ -139,12 +150,8 @@ void ClientModel::updateTimer()
 
 void ClientModel::updateMnTimer()
 {
-    // Get required lock upfront. This avoids the GUI from getting stuck on
-    // periodical polls if the core is holding the locks for a longer time -
-    // for example, during a wallet rescan.
-    TRY_LOCK(cs_main, lockMain);
-    if (!lockMain)
-        return;
+    // Following method is locking the mnmanager mutex for now,
+    // future: move to an event based update.
     QString newMasternodeCountString = getMasternodeCountString();
 
     if (cachedMasternodeCountString != newMasternodeCountString) {

src/qt/clientmodel.h

@@ -89,6 +89,9 @@ class ClientModel : public QObject
     // Start/Stop the masternode polling timer
     void startMasternodesTimer();
     void stopMasternodesTimer();
+    // Force a MN count update calling mnmanager directly locking its internal mutex.
+    // Future todo: implement an event based update and remove the lock requirement.
+    QString getMasternodesCount();
 
 private:
     QString getMasternodeCountString() const;

src/qt/pivx/settings/settingsinformationwidget.cpp

@@ -1,6 +1,6 @@
 // Copyright (c) 2019-2020 The PIVX developers
 // Distributed under the MIT software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+// file COPYING or https://www.opensource.org/licenses/mit-license.php.
 
 #include "qt/pivx/settings/settingsinformationwidget.h"
 #include "qt/pivx/settings/forms/ui_settingsinformationwidget.h"
@@ -14,6 +14,8 @@
 
 #include <QDir>
 
+#define REQUEST_UPDATE_MN_COUNT 0
+
 SettingsInformationWidget::SettingsInformationWidget(PIVXGUI* _window,QWidget *parent) :
     PWidget(_window,parent),
     ui(new Ui::SettingsInformationWidget)
@@ -165,6 +167,8 @@ void SettingsInformationWidget::showEvent(QShowEvent *event)
     QWidget::showEvent(event);
     if (clientModel) {
         clientModel->startMasternodesTimer();
+        // Initial masternodes count value, running in a worker thread to not lock mnmanager mutex in the main thread.
+        execute(REQUEST_UPDATE_MN_COUNT);
     }
 }
 
@@ -175,6 +179,21 @@ void SettingsInformationWidget::hideEvent(QHideEvent *event) {
     }
 }
 
+void SettingsInformationWidget::run(int type)
+{
+    if (type == REQUEST_UPDATE_MN_COUNT) {
+        QMetaObject::invokeMethod(this, "setMasternodeCount",
+                                  Qt::QueuedConnection, Q_ARG(QString, clientModel->getMasternodesCount()));
+    }
+}
+
+void SettingsInformationWidget::onError(QString error, int type)
+{
+    if (type == REQUEST_UPDATE_MN_COUNT) {
+        setMasternodeCount(tr("No available data"));
+    }
+}
+
 SettingsInformationWidget::~SettingsInformationWidget()
 {
     delete ui;

src/qt/pivx/settings/settingsinformationwidget.h

@@ -19,19 +19,22 @@ class SettingsInformationWidget : public PWidget
 
 public:
     explicit SettingsInformationWidget(PIVXGUI* _window, QWidget *parent = nullptr);
-    ~SettingsInformationWidget();
+    ~SettingsInformationWidget() override;
 
     void loadClientModel() override;
 
+    void run(int type) override;
+    void onError(QString error, int type) override;
+
 private Q_SLOTS:
     void setNumConnections(int count);
     void setNumBlocks(int count);
-    void setMasternodeCount(const QString& strMasternodes);
     void showEvent(QShowEvent* event) override;
     void hideEvent(QHideEvent* event) override;
 
 public Q_SLOTS:
     void openNetworkMonitor();
+    void setMasternodeCount(const QString& strMasternodes);
 
 private:
     Ui::SettingsInformationWidget *ui;