From 5aec0ff207e9427b8756471eb003fd68859f67b1 Mon Sep 17 00:00:00 2001
From: Justin Clark-Casey (justincc)
Date: Wed, 25 Jul 2012 23:27:00 +0100
Subject: Move Watchdog and MemoryWatchdog classes into
OpenSim.Framework.Monitoring with other monitoring code from
OpenSim.Framework
---
OpenSim/Framework/Monitoring/Watchdog.cs | 334 +++++++++++++++++++++++++++++++
1 file changed, 334 insertions(+)
create mode 100644 OpenSim/Framework/Monitoring/Watchdog.cs
(limited to 'OpenSim/Framework/Monitoring/Watchdog.cs')
diff --git a/OpenSim/Framework/Monitoring/Watchdog.cs b/OpenSim/Framework/Monitoring/Watchdog.cs
new file mode 100644
index 0000000..d4cf02f
--- /dev/null
+++ b/OpenSim/Framework/Monitoring/Watchdog.cs
@@ -0,0 +1,334 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of the OpenSimulator Project nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using log4net;
+
+namespace OpenSim.Framework.Monitoring
+{
+ ///
+ /// Manages launching threads and keeping watch over them for timeouts
+ ///
+ public static class Watchdog
+ {
+ /// Timer interval in milliseconds for the watchdog timer
+ const double WATCHDOG_INTERVAL_MS = 2500.0d;
+
+ /// Default timeout in milliseconds before a thread is considered dead
+ public const int DEFAULT_WATCHDOG_TIMEOUT_MS = 5000;
+
+ [System.Diagnostics.DebuggerDisplay("{Thread.Name}")]
+ public class ThreadWatchdogInfo
+ {
+ public Thread Thread { get; private set; }
+
+ ///
+ /// Approximate tick when this thread was started.
+ ///
+ ///
+ /// Not terribly good since this quickly wraps around.
+ ///
+ public int FirstTick { get; private set; }
+
+ ///
+ /// Last time this heartbeat update was invoked
+ ///
+ public int LastTick { get; set; }
+
+ ///
+ /// Number of milliseconds before we notify that the thread is having a problem.
+ ///
+ public int Timeout { get; set; }
+
+ ///
+ /// Is this thread considered timed out?
+ ///
+ public bool IsTimedOut { get; set; }
+
+ ///
+ /// Will this thread trigger the alarm function if it has timed out?
+ ///
+ public bool AlarmIfTimeout { get; set; }
+
+ ///
+ /// Method execute if alarm goes off. If null then no alarm method is fired.
+ ///
+ public Func AlarmMethod { get; set; }
+
+ public ThreadWatchdogInfo(Thread thread, int timeout)
+ {
+ Thread = thread;
+ Timeout = timeout;
+ FirstTick = Environment.TickCount & Int32.MaxValue;
+ LastTick = FirstTick;
+ }
+ }
+
+ ///
+ /// This event is called whenever a tracked thread is
+ /// stopped or has not called UpdateThread() in time<
+ /// /summary>
+ public static event Action OnWatchdogTimeout;
+
+ private static readonly ILog m_log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+ private static Dictionary m_threads;
+ private static System.Timers.Timer m_watchdogTimer;
+
+ ///
+ /// Last time the watchdog thread ran.
+ ///
+ ///
+ /// Should run every WATCHDOG_INTERVAL_MS
+ ///
+ public static int LastWatchdogThreadTick { get; private set; }
+
+ static Watchdog()
+ {
+ m_threads = new Dictionary();
+ m_watchdogTimer = new System.Timers.Timer(WATCHDOG_INTERVAL_MS);
+ m_watchdogTimer.AutoReset = false;
+ m_watchdogTimer.Elapsed += WatchdogTimerElapsed;
+
+ // Set now so we don't get alerted on the first run
+ LastWatchdogThreadTick = Environment.TickCount & Int32.MaxValue;
+
+ m_watchdogTimer.Start();
+ }
+
+ ///
+ /// Start a new thread that is tracked by the watchdog timer.
+ ///
+ /// The method that will be executed in a new thread
+ /// A name to give to the new thread
+ /// Priority to run the thread at
+ /// True to run this thread as a background thread, otherwise false
+ /// Trigger an alarm function is we have timed out
+ /// The newly created Thread object
+ public static Thread StartThread(
+ ThreadStart start, string name, ThreadPriority priority, bool isBackground, bool alarmIfTimeout)
+ {
+ return StartThread(start, name, priority, isBackground, alarmIfTimeout, null, DEFAULT_WATCHDOG_TIMEOUT_MS);
+ }
+
+ ///
+ /// Start a new thread that is tracked by the watchdog timer
+ ///
+ /// The method that will be executed in a new thread
+ /// A name to give to the new thread
+ /// Priority to run the thread at
+ /// True to run this thread as a background
+ /// thread, otherwise false
+ /// Trigger an alarm function is we have timed out
+ ///
+ /// Alarm method to call if alarmIfTimeout is true and there is a timeout.
+ /// Normally, this will just return some useful debugging information.
+ ///
+ /// Number of milliseconds to wait until we issue a warning about timeout.
+ /// The newly created Thread object
+ public static Thread StartThread(
+ ThreadStart start, string name, ThreadPriority priority, bool isBackground,
+ bool alarmIfTimeout, Func alarmMethod, int timeout)
+ {
+ Thread thread = new Thread(start);
+ thread.Name = name;
+ thread.Priority = priority;
+ thread.IsBackground = isBackground;
+
+ ThreadWatchdogInfo twi
+ = new ThreadWatchdogInfo(thread, timeout)
+ { AlarmIfTimeout = alarmIfTimeout, AlarmMethod = alarmMethod };
+
+ m_log.DebugFormat(
+ "[WATCHDOG]: Started tracking thread {0}, ID {1}", twi.Thread.Name, twi.Thread.ManagedThreadId);
+
+ lock (m_threads)
+ m_threads.Add(twi.Thread.ManagedThreadId, twi);
+
+ thread.Start();
+
+ return thread;
+ }
+
+ ///
+ /// Marks the current thread as alive
+ ///
+ public static void UpdateThread()
+ {
+ UpdateThread(Thread.CurrentThread.ManagedThreadId);
+ }
+
+ ///
+ /// Stops watchdog tracking on the current thread
+ ///
+ ///
+ /// True if the thread was removed from the list of tracked
+ /// threads, otherwise false
+ ///
+ public static bool RemoveThread()
+ {
+ return RemoveThread(Thread.CurrentThread.ManagedThreadId);
+ }
+
+ private static bool RemoveThread(int threadID)
+ {
+ lock (m_threads)
+ return m_threads.Remove(threadID);
+ }
+
+ public static bool AbortThread(int threadID)
+ {
+ lock (m_threads)
+ {
+ if (m_threads.ContainsKey(threadID))
+ {
+ ThreadWatchdogInfo twi = m_threads[threadID];
+ twi.Thread.Abort();
+ RemoveThread(threadID);
+
+ return true;
+ }
+ else
+ {
+ return false;
+ }
+ }
+ }
+
+ private static void UpdateThread(int threadID)
+ {
+ ThreadWatchdogInfo threadInfo;
+
+ // Although TryGetValue is not a thread safe operation, we use a try/catch here instead
+ // of a lock for speed. Adding/removing threads is a very rare operation compared to
+ // UpdateThread(), and a single UpdateThread() failure here and there won't break
+ // anything
+ try
+ {
+ if (m_threads.TryGetValue(threadID, out threadInfo))
+ {
+ threadInfo.LastTick = Environment.TickCount & Int32.MaxValue;
+ threadInfo.IsTimedOut = false;
+ }
+ else
+ {
+ m_log.WarnFormat("[WATCHDOG]: Asked to update thread {0} which is not being monitored", threadID);
+ }
+ }
+ catch { }
+ }
+
+ ///
+ /// Get currently watched threads for diagnostic purposes
+ ///
+ ///
+ public static ThreadWatchdogInfo[] GetThreadsInfo()
+ {
+ lock (m_threads)
+ return m_threads.Values.ToArray();
+ }
+
+ ///
+ /// Return the current thread's watchdog info.
+ ///
+ /// The watchdog info. null if the thread isn't being monitored.
+ public static ThreadWatchdogInfo GetCurrentThreadInfo()
+ {
+ lock (m_threads)
+ {
+ if (m_threads.ContainsKey(Thread.CurrentThread.ManagedThreadId))
+ return m_threads[Thread.CurrentThread.ManagedThreadId];
+ }
+
+ return null;
+ }
+
+ ///
+ /// Check watched threads. Fire alarm if appropriate.
+ ///
+ ///
+ ///
+ private static void WatchdogTimerElapsed(object sender, System.Timers.ElapsedEventArgs e)
+ {
+ int now = Environment.TickCount & Int32.MaxValue;
+ int msElapsed = now - LastWatchdogThreadTick;
+
+ if (msElapsed > WATCHDOG_INTERVAL_MS * 2)
+ m_log.WarnFormat(
+ "[WATCHDOG]: {0} ms since Watchdog last ran. Interval should be approximately {1} ms",
+ msElapsed, WATCHDOG_INTERVAL_MS);
+
+ LastWatchdogThreadTick = Environment.TickCount & Int32.MaxValue;
+
+ Action callback = OnWatchdogTimeout;
+
+ if (callback != null)
+ {
+ List callbackInfos = null;
+
+ lock (m_threads)
+ {
+ foreach (ThreadWatchdogInfo threadInfo in m_threads.Values)
+ {
+ if (threadInfo.Thread.ThreadState == ThreadState.Stopped)
+ {
+ RemoveThread(threadInfo.Thread.ManagedThreadId);
+
+ if (callbackInfos == null)
+ callbackInfos = new List();
+
+ callbackInfos.Add(threadInfo);
+ }
+ else if (!threadInfo.IsTimedOut && now - threadInfo.LastTick >= threadInfo.Timeout)
+ {
+ threadInfo.IsTimedOut = true;
+
+ if (threadInfo.AlarmIfTimeout)
+ {
+ if (callbackInfos == null)
+ callbackInfos = new List();
+
+ callbackInfos.Add(threadInfo);
+ }
+ }
+ }
+ }
+
+ if (callbackInfos != null)
+ foreach (ThreadWatchdogInfo callbackInfo in callbackInfos)
+ callback(callbackInfo);
+ }
+
+ if (MemoryWatchdog.Enabled)
+ MemoryWatchdog.Update();
+
+ m_watchdogTimer.Start();
+ }
+ }
+}
\ No newline at end of file
--
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