From bf7da71eafcbe89124c220e0be166e6c96bed940 Mon Sep 17 00:00:00 2001
From: Seth Alves <seth.alves@gmail.com>
Date: Mon, 26 Jun 2017 15:07:22 -0700
Subject: [PATCH 1/2] use QEventLoop and a timer for a less CPU using sleep +
 event-processing

---
 libraries/script-engine/src/ScriptEngine.cpp | 29 +++++++++-----------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/libraries/script-engine/src/ScriptEngine.cpp b/libraries/script-engine/src/ScriptEngine.cpp
index d9b41bb55d..017124af1c 100644
--- a/libraries/script-engine/src/ScriptEngine.cpp
+++ b/libraries/script-engine/src/ScriptEngine.cpp
@@ -1067,24 +1067,21 @@ void ScriptEngine::run() {
         // on shutdown and stop... so we want to loop and sleep until we've spent our time in
         // purgatory, constantly checking to see if our script was asked to end
         bool processedEvents = false;
-        while (!_isFinished && clock::now() < sleepUntil) {
-
-            {
-                PROFILE_RANGE(script, "processEvents-sleep");
-                QCoreApplication::processEvents(); // before we sleep again, give events a chance to process
+        if (!_isFinished) {
+            PROFILE_RANGE(script, "processEvents-sleep");
+            std::chrono::milliseconds sleepFor =
+                std::chrono::duration_cast<std::chrono::milliseconds>(sleepUntil - clock::now());
+            if (sleepFor > std::chrono::milliseconds(0)) {
+                QEventLoop loop;
+                QTimer timer;
+                timer.setSingleShot(true);
+                connect(&timer, SIGNAL(timeout()), &loop, SLOT(quit()));
+                timer.start(sleepFor);
+                loop.exec();
+            } else {
+                QCoreApplication::processEvents();
             }
             processedEvents = true;
-
-            // If after processing events, we're past due, exit asap
-            if (clock::now() >= sleepUntil) {
-                break;
-            }
-
-            // We only want to sleep a small amount so that any pending events (like timers or invokeMethod events)
-            // will be able to process quickly.
-            static const int SMALL_SLEEP_AMOUNT = 100;
-            auto smallSleepUntil = clock::now() + static_cast<std::chrono::microseconds>(SMALL_SLEEP_AMOUNT);
-            std::this_thread::sleep_until(smallSleepUntil);
         }
 
         PROFILE_RANGE(script, "ScriptMainLoop");

From 4f672f93d20ed87aec24b57f3fd37c3a6d2e76d8 Mon Sep 17 00:00:00 2001
From: Seth Alves <seth.alves@gmail.com>
Date: Mon, 26 Jun 2017 16:03:39 -0700
Subject: [PATCH 2/2] avoid cast that isn't always available

---
 libraries/script-engine/src/ScriptEngine.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/script-engine/src/ScriptEngine.cpp b/libraries/script-engine/src/ScriptEngine.cpp
index 017124af1c..81b815a34b 100644
--- a/libraries/script-engine/src/ScriptEngine.cpp
+++ b/libraries/script-engine/src/ScriptEngine.cpp
@@ -1076,7 +1076,7 @@ void ScriptEngine::run() {
                 QTimer timer;
                 timer.setSingleShot(true);
                 connect(&timer, SIGNAL(timeout()), &loop, SLOT(quit()));
-                timer.start(sleepFor);
+                timer.start(sleepFor.count());
                 loop.exec();
             } else {
                 QCoreApplication::processEvents();