From 607a1328ff83fcccd620472ce14cb2e5a580aaea Mon Sep 17 00:00:00 2001
From: Grzegorz Krajewski <krajekg@gmail.com>
Date: Tue, 17 Nov 2015 23:01:50 +0100
Subject: [PATCH] Throw a runtime_error exception for start/stop

Throwing a runtime_error exception after Timer::Start or Timer::Stop has been called twice.
---
 src/mlpack/core/util/timers.cpp | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/mlpack/core/util/timers.cpp b/src/mlpack/core/util/timers.cpp
index 0dbd7d55a7..4c649b24b4 100644
--- a/src/mlpack/core/util/timers.cpp
+++ b/src/mlpack/core/util/timers.cpp
@@ -33,6 +33,17 @@ inline void timersub(const timeval* tvp, const timeval* uvp, timeval* vvp)
  */
 void Timer::Start(const std::string& name)
 {
+    if((timerState[name] == 1) && (name != "total_time"))
+  {
+    std::ostringstream error;
+    error << "Timer::Start(): timer '" << name
+	      << "' has already been " << "started";
+	
+    throw std::runtime_error(error.str());
+  }
+  
+  timerState[name] = true;
+  
   CLI::GetSingleton().timer.StartTimer(name);
 }
 
@@ -41,6 +52,17 @@ void Timer::Start(const std::string& name)
  */
 void Timer::Stop(const std::string& name)
 {
+    if((timerState[name] == 0) && (name != "total_time"))
+  {
+    std::ostringstream error;
+    error << "Timer::Stop(): timer '" << name
+	<< "' has already been " << "stopped";
+	
+    throw std::runtime_error(error.str());
+  }
+  
+  timerState[name] = false;
+  
   CLI::GetSingleton().timer.StopTimer(name);
 }