From 3eeb3a539dda788907121e1f32a5e9dc6883e242 Mon Sep 17 00:00:00 2001
From: Atlante45 <clement.brisset@gmail.com>
Date: Tue, 22 Apr 2014 11:48:43 -0700
Subject: [PATCH] Fixed lack of resolution in usecTimestampNow()

---
 assignment-client/src/main.cpp      |  1 +
 domain-server/src/main.cpp          |  2 ++
 interface/src/main.cpp              |  1 +
 libraries/shared/src/SharedUtil.cpp | 22 +++++++++++++++++++---
 libraries/shared/src/SharedUtil.h   |  1 +
 5 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/assignment-client/src/main.cpp b/assignment-client/src/main.cpp
index 24d19ddef6..7132b5c38a 100644
--- a/assignment-client/src/main.cpp
+++ b/assignment-client/src/main.cpp
@@ -17,6 +17,7 @@
 #include "AssignmentClientMonitor.h"
 
 int main(int argc, char* argv[]) {
+    initialiseUsecTimestampNow();
     
 #ifndef WIN32
     setvbuf(stdout, NULL, _IOLBF, 0);
diff --git a/domain-server/src/main.cpp b/domain-server/src/main.cpp
index bdb10cb56f..871c16a215 100644
--- a/domain-server/src/main.cpp
+++ b/domain-server/src/main.cpp
@@ -18,10 +18,12 @@
 #include <QtCore/QCoreApplication>
 
 #include <Logging.h>
+#include <SharedUtil.h>
 
 #include "DomainServer.h"
 
 int main(int argc, char* argv[]) {
+    initialiseUsecTimestampNow();
     
 #ifndef WIN32
     setvbuf(stdout, NULL, _IOLBF, 0);
diff --git a/interface/src/main.cpp b/interface/src/main.cpp
index 2bb0633f24..6f9dc5e3bd 100644
--- a/interface/src/main.cpp
+++ b/interface/src/main.cpp
@@ -16,6 +16,7 @@
 #include <SharedUtil.h>
 
 int main(int argc, const char * argv[]) {
+    initialiseUsecTimestampNow();
     QElapsedTimer startupTime;
     startupTime.start();
     
diff --git a/libraries/shared/src/SharedUtil.cpp b/libraries/shared/src/SharedUtil.cpp
index a13772d862..78ef997c35 100644
--- a/libraries/shared/src/SharedUtil.cpp
+++ b/libraries/shared/src/SharedUtil.cpp
@@ -21,18 +21,34 @@
 
 #include <QtCore/QDebug>
 #include <QDateTime>
+#include <QElapsedTimer>
 
 #include "OctalCode.h"
 #include "SharedUtil.h"
 
-int usecTimestampNowAdjust = 0;
+
+static qint64 TIME_REFERENCE = 0; // in usec
+static QElapsedTimer timestampTimer;
+static int usecTimestampNowAdjust = 0; // in usec
+
+void initialiseUsecTimestampNow() {
+    static bool initialised = false;
+    if (initialised) {
+        qDebug() << "[WARNING] Double initialisation of usecTimestampNow().";
+        return;
+    }
+    
+    TIME_REFERENCE = QDateTime::currentMSecsSinceEpoch() * 1000; // ms to usec
+    initialised = true;
+}
+
 void usecTimestampNowForceClockSkew(int clockSkew) {
     ::usecTimestampNowAdjust = clockSkew;
 }
 
 quint64 usecTimestampNow() {
-    qint64 msecSinceEpoch = QDateTime::currentMSecsSinceEpoch();
-    return msecSinceEpoch * 1000 + ::usecTimestampNowAdjust;
+    //          usec                       nsec to usec                   usec
+    return TIME_REFERENCE + timestampTimer.nsecsElapsed() / 1000 + ::usecTimestampNowAdjust;
 }
 
 float randFloat() {
diff --git a/libraries/shared/src/SharedUtil.h b/libraries/shared/src/SharedUtil.h
index 4a3fe2a129..54d599070d 100644
--- a/libraries/shared/src/SharedUtil.h
+++ b/libraries/shared/src/SharedUtil.h
@@ -60,6 +60,7 @@ static const quint64 USECS_PER_SECOND = USECS_PER_MSEC * MSECS_PER_SECOND;
 
 const int BITS_IN_BYTE  = 8;
 
+void initialiseUsecTimestampNow();
 quint64 usecTimestampNow();
 void usecTimestampNowForceClockSkew(int clockSkew);