1 files changed, 141 insertions, 0 deletions
diff --git a/indra/llcommon/lldeadmantimer.cpp b/indra/llcommon/lldeadmantimer.cpp
new file mode 100644
index 0000000000..2f48d13c2d
--- /dev/null
+++ b/indra/llcommon/lldeadmantimer.cpp
@@ -0,0 +1,141 @@
+/** 
+* @file lldeadmantimer.cpp
+* @brief Simple deadman-switch timer.
+* @author monty@lindenlab.com
+*
+* $LicenseInfo:firstyear=2013&license=viewerlgpl$
+* Second Life Viewer Source Code
+* Copyright (C) 2013, Linden Research, Inc.
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation;
+* version 2.1 of the License only.
+*
+* This library is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*
+* Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+* $/LicenseInfo$
+*/
+
+
+#include "lldeadmantimer.h"
+
+
+LLDeadmanTimer::LLDeadmanTimer(F64 horizon)
+	: mHorizon(U64(horizon * gClockFrequency)),
+	  mActive(false),			// If true, a timer is running.
+	  mDone(false),				// If true, timer has completed and can be read (once)
+	  mStarted(U64L(0)),
+	  mExpires(U64L(0)),
+	  mStopped(U64L(0)),
+	  mCount(U64L(0))
+{}
+
+
+void LLDeadmanTimer::start(U64 now)
+{
+	// *TODO:  If active, let's complete an existing timer and save
+	// the result to the side.  I think this will be useful later.
+	// For now, wipe out anything in progress, start fresh.
+	
+	if (! now)
+	{
+		now = LLTimer::getCurrentClockCount();
+	}
+	mActive = true;
+	mDone = false;
+	mStarted = now;
+	mExpires = now + mHorizon;
+	mStopped = now;
+	mCount = U64L(0);
+}
+
+
+void LLDeadmanTimer::stop(U64 now)
+{
+	if (! mActive)
+	{
+		return;
+	}
+
+	if (! now)
+	{
+		now = LLTimer::getCurrentClockCount();
+	}
+	mStopped = now;
+	mActive = false;
+	mDone = true;
+}
+
+
+bool LLDeadmanTimer::isExpired(F64 & started, F64 & stopped, U64 & count, U64 now)
+{
+	if (! mActive)
+	{
+		return false;
+	}
+	
+	if (! mDone)
+	{
+		if (! now)
+		{
+			now = LLTimer::getCurrentClockCount();
+		}
+
+		if (now > mExpires)
+		{
+			// mStopped from ringBell() is the value we want
+			mActive = false;
+			mDone = true;
+		}
+	}
+
+	if (! mDone)
+	{
+		return false;
+	}
+	
+	started = mStarted * gClockFrequencyInv;
+	stopped = mStopped * gClockFrequencyInv;
+	count = mCount;
+	mDone = false;
+
+	return true;
+}
+
+	
+void LLDeadmanTimer::ringBell(U64 now)
+{
+	if (! mActive)
+	{
+		return;
+	}
+	
+	if (! now)
+	{
+		now = LLTimer::getCurrentClockCount();
+	}
+
+	if (now > mExpires)
+	{
+		mActive = false;
+		mDone = true;
+	}
+	else
+	{
+		mStopped = now;
+		mExpires = now + mHorizon;
+		++mCount;
+	}
+	
+	return;
+}
+