From f485e0fa1fc4c182f8e75ad97bf5cdc8deff0ba2 Mon Sep 17 00:00:00 2001
From: Aditya Kulkarni <adityapk@gmail.com>
Date: Wed, 7 Nov 2018 21:11:53 -0800
Subject: [PATCH] Proper shutdown procedure

---
 src/connection.cpp | 16 ++++++++++++++++
 src/connection.h   |  5 +++++
 src/rpc.cpp        |  9 ++++++---
 src/rpc.h          |  1 +
 4 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/connection.cpp b/src/connection.cpp
index 7b4be73..42ff779 100644
--- a/src/connection.cpp
+++ b/src/connection.cpp
@@ -487,10 +487,19 @@ Connection::~Connection() {
 
 void Connection::doRPC(const json& payload, const std::function<void(json)>& cb, 
                        const std::function<void(QNetworkReply*, const json&)>& ne) {
+    if (shutdownInProgress) {
+        qDebug() << "Ignoring RPC because shutdown in progress";
+        return;
+    }
+
     QNetworkReply *reply = restclient->post(*request, QByteArray::fromStdString(payload.dump()));
 
     QObject::connect(reply, &QNetworkReply::finished, [=] {
         reply->deleteLater();
+        if (shutdownInProgress) {
+            qDebug() << "Ignoring callback because shutdown in progress";
+            return;
+        }
         
         if (reply->error() != QNetworkReply::NoError) {
             auto parsed = json::parse(reply->readAll(), nullptr, false);
@@ -530,3 +539,10 @@ void Connection::showTxError(const QString& error) {
     QMessageBox::critical(main, "Transaction Error", "There was an error sending the transaction. The error was: \n\n"
         + error, QMessageBox::StandardButton::Ok);
 }
+
+/**
+ * Prevent all future calls from going through
+ */ 
+void Connection::shutdown() {
+    shutdownInProgress = true;
+}
\ No newline at end of file
diff --git a/src/connection.h b/src/connection.h
index fc3c3c0..95e157f 100644
--- a/src/connection.h
+++ b/src/connection.h
@@ -90,6 +90,8 @@ public:
     std::shared_ptr<ConnectionConfig>   config;
     MainWindow*                         main;
 
+    void shutdown();
+
     void doRPC(const json& payload, const std::function<void(json)>& cb, 
                const std::function<void(QNetworkReply*, const json&)>& ne);
     void doRPCWithDefaultErrorHandling(const json& payload, const std::function<void(json)>& cb);
@@ -143,6 +145,9 @@ public:
         });
         waitTimer->start(100);    
     }
+
+private:
+    bool shutdownInProgress = false;    
 };
 
 #endif
diff --git a/src/rpc.cpp b/src/rpc.cpp
index da02c53..db5da25 100644
--- a/src/rpc.cpp
+++ b/src/rpc.cpp
@@ -857,6 +857,8 @@ void RPC::shutdownZcashd() {
     };
     
     conn->doRPCWithDefaultErrorHandling(payload, [=](auto) {});
+    conn->shutdown();
+
 
     QMessageBox d(main);
     d.setIcon(QMessageBox::Icon::Information);
@@ -869,11 +871,12 @@ void RPC::shutdownZcashd() {
     // We capture by reference all the local variables because of the d.exec() 
     // below, which blocks this function until we exit. 
     QObject::connect(&waiter, &QTimer::timeout, [&] () {
-        if (ezcashd->atEnd()) {
+        if (ezcashd->atEnd() && ezcashd->processId() == 0) {
             qDebug() << "Ended";
-            d.accept();
+            waiter.stop();
+            QTimer::singleShot(1000, [&]() { d.accept(); });
         } else {
-            qDebug() << "Not ended";
+            qDebug() << "Not ended, continuing to wait...";
         }
     });
     waiter.start(1000);
diff --git a/src/rpc.h b/src/rpc.h
index c2539c3..6d2d8e9 100644
--- a/src/rpc.h
+++ b/src/rpc.h
@@ -112,6 +112,7 @@ private:
 
     // Current balance in the UI. If this number updates, then refresh the UI
     QString                     currentBalance;
+
     // First time warning flag for no connection
     bool                        firstTime = true;
 };