Timer.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / clr / src / BCL / System / Threading / Timer.cs / 1 / Timer.cs
                        

                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
/*==============================================================================
** 
** Class: TimerQueue 
**
** 
** Purpose: Class for creating and managing a threadpool
**
**
=============================================================================*/ 

namespace System.Threading { 
    using System.Threading; 
    using System;
    using System.Security; 
    using System.Security.Permissions;
    using Microsoft.Win32;
    using System.Runtime.CompilerServices;
    using System.Runtime.InteropServices; 
    using System.Runtime.ConstrainedExecution;
 
    internal class _TimerCallback 
    {
        TimerCallback _timerCallback; 
        ExecutionContext _executionContext;
        Object _state;
        static internal ContextCallback _ccb = new ContextCallback(TimerCallback_Context);
        static internal void TimerCallback_Context(Object state) 
        {
            _TimerCallback helper = (_TimerCallback) state; 
            helper._timerCallback(helper._state); 

        } 

        internal _TimerCallback(TimerCallback timerCallback, Object state, ref StackCrawlMark stackMark)
        {
            _timerCallback = timerCallback; 
            _state = state;
            if (!ExecutionContext.IsFlowSuppressed()) 
            { 
                _executionContext = ExecutionContext.Capture(ref stackMark);
                ExecutionContext.ClearSyncContext(_executionContext); 
            }
        }

        // call back helper 
        static internal void PerformTimerCallback(Object state)
        { 
            _TimerCallback helper = (_TimerCallback)state; 

            BCLDebug.Assert(helper != null, "Null state passed to PerformTimerCallback!"); 
            // call directly if EC flow is suppressed
            if (helper._executionContext == null)
            {
                TimerCallback callback = helper._timerCallback; 
                callback(helper._state);
            } 
            else 
            {
                // From this point on we can use useExecutionContext for this callback 
                ExecutionContext.Run(helper._executionContext.CreateCopy(), _ccb, helper);
            }
        }
    } 

[System.Runtime.InteropServices.ComVisible(true)] 
    public delegate void TimerCallback(Object state); 

    [HostProtection(Synchronization=true, ExternalThreading=true)] 
    internal sealed class TimerBase : CriticalFinalizerObject, IDisposable
    {
#pragma warning disable 169
        private IntPtr     timerHandle; 
        private IntPtr     delegateInfo;
#pragma warning restore 169 
        private int        timerDeleted; 
        private int        m_lock = 0;
 
        ~TimerBase()
        {
            // lock(this) cannot be used reliably in Cer since thin lock could be
            // promoted to syncblock and that is not a guaranteed operation 
            bool bLockTaken = false;
            do 
            { 
                if (Interlocked.CompareExchange(ref m_lock, 1, 0) == 0)
                { 
                    bLockTaken = true;
                    try
                    {
                        DeleteTimerNative(null); 
                    }
                    finally 
                    { 
                        m_lock = 0;
                    } 
                }
                Thread.SpinWait(1);     // yield to processor
            }
            while (!bLockTaken); 
        }
 
        internal void AddTimer(TimerCallback   callback, 
                                           Object          state,
                                           UInt32      dueTime, 
                                           UInt32          period,
                                           ref StackCrawlMark  stackMark
                                           )
        { 
            if (callback != null)
            { 
                _TimerCallback callbackHelper = new _TimerCallback(callback, state, ref stackMark); 
                state = (Object)callbackHelper;
                AddTimerNative(state, dueTime, period, ref stackMark); 
                timerDeleted = 0;
            }
            else
            { 
                throw new ArgumentNullException("TimerCallback");
            } 
        } 

        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)] 
        internal bool ChangeTimer(UInt32 dueTime,UInt32 period)
        {
            bool status = false;
            bool bLockTaken = false; 

            // prepare here to prevent threadabort from occuring which could 
            // destroy m_lock state.  lock(this) can't be used due to critical 
            // finalizer and thinlock/syncblock escalation.
            RuntimeHelpers.PrepareConstrainedRegions(); 
            try
            {
            }
            finally 
            {
                do 
                { 
                    if (Interlocked.CompareExchange(ref m_lock, 1, 0) == 0)
                    { 
                        bLockTaken = true;
                        try
                        {
                            if (timerDeleted != 0) 
                                throw new ObjectDisposedException(null, Environment.GetResourceString("ObjectDisposed_Generic"));
                            status = ChangeTimerNative(dueTime,period); 
                        } 
                        finally
                        { 
                            m_lock = 0;
                        }
                    }
                    Thread.SpinWait(1);     // yield to processor 
                }
                while (!bLockTaken); 
            } 
            return status;
 
        }

        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
        internal bool Dispose(WaitHandle notifyObject) 
        {
            bool status = false; 
            bool bLockTaken = false; 
            RuntimeHelpers.PrepareConstrainedRegions();
            try 
            {
            }
            finally
            { 
                do
                { 
                    if (Interlocked.CompareExchange(ref m_lock, 1, 0) == 0) 
                    {
                        bLockTaken = true; 
                        try
                        {
                            status = DeleteTimerNative(notifyObject.SafeWaitHandle);
                        } 
                        finally
                        { 
                            m_lock = 0; 
                        }
                    } 
                    Thread.SpinWait(1);     // yield to processor
                }
                while (!bLockTaken);
                GC.SuppressFinalize(this); 
            }
 
            return status; 
        }
 
        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
        public void Dispose()
        {
            bool bLockTaken = false; 
            RuntimeHelpers.PrepareConstrainedRegions();
            try 
            { 
            }
            finally 
            {
                do
                {
                    if (Interlocked.CompareExchange(ref m_lock, 1, 0) == 0) 
                    {
                        bLockTaken = true; 
                        try 
                        {
                            DeleteTimerNative(null); 
                        }
                        finally
                        {
                            m_lock = 0; 
                        }
                    } 
                    Thread.SpinWait(1);     // yield to processor 
                }
                while (!bLockTaken); 
                GC.SuppressFinalize(this);
            }
        }
 
        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        private extern void AddTimerNative(Object   state, 
                                           UInt32      dueTime, 
                                           UInt32          period,
                                           ref StackCrawlMark  stackMark 
                                           );

        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        private  extern bool ChangeTimerNative(UInt32 dueTime,UInt32 period); 

        [MethodImplAttribute(MethodImplOptions.InternalCall)] 
        private  extern bool DeleteTimerNative(SafeHandle notifyObject); 

    } 

    [HostProtection(Synchronization=true, ExternalThreading=true)]
[System.Runtime.InteropServices.ComVisible(true)]
    public sealed class Timer : MarshalByRefObject, IDisposable 
    {
        private const UInt32 MAX_SUPPORTED_TIMEOUT = (uint)0xfffffffe; 
        private TimerBase timerBase; 

        public Timer(TimerCallback callback, 
                     Object        state,
                     int           dueTime,
                     int           period)
        { 
            if (dueTime < -1)
                throw new ArgumentOutOfRangeException("dueTime", Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegOrNegative1")); 
            if (period < -1 ) 
                throw new ArgumentOutOfRangeException("period", Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegOrNegative1"));
            StackCrawlMark stackMark = StackCrawlMark.LookForMyCaller; 

            TimerSetup(callback,state,(UInt32)dueTime,(UInt32)period,ref stackMark);
        }
 
        public Timer(TimerCallback callback,
                     Object        state, 
                     TimeSpan      dueTime, 
                     TimeSpan      period)
        { 
            long dueTm = (long)dueTime.TotalMilliseconds;
            if (dueTm < -1)
                throw new ArgumentOutOfRangeException("dueTm",Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegOrNegative1"));
            if (dueTm > MAX_SUPPORTED_TIMEOUT) 
                throw new ArgumentOutOfRangeException("dueTm",Environment.GetResourceString("ArgumentOutOfRange_TimeoutTooLarge"));
 
            long periodTm = (long)period.TotalMilliseconds; 
            if (periodTm < -1)
                throw new ArgumentOutOfRangeException("periodTm",Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegOrNegative1")); 
            if (periodTm > MAX_SUPPORTED_TIMEOUT)
                throw new ArgumentOutOfRangeException("periodTm",Environment.GetResourceString("ArgumentOutOfRange_PeriodTooLarge"));

            StackCrawlMark stackMark = StackCrawlMark.LookForMyCaller; 
            TimerSetup(callback,state,(UInt32)dueTm,(UInt32)periodTm,ref stackMark);
        } 
 
        [CLSCompliant(false)]
        public Timer(TimerCallback callback, 
                     Object        state,
                     UInt32        dueTime,
                     UInt32        period)
        { 
            StackCrawlMark stackMark = StackCrawlMark.LookForMyCaller;
            TimerSetup(callback,state,dueTime,period,ref stackMark); 
        } 

        public Timer(TimerCallback callback, 
                     Object        state,
                     long          dueTime,
                     long          period)
        { 
            if (dueTime < -1)
                throw new ArgumentOutOfRangeException("dueTime",Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegOrNegative1")); 
            if (period < -1) 
                throw new ArgumentOutOfRangeException("period",Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegOrNegative1"));
            if (dueTime > MAX_SUPPORTED_TIMEOUT) 
                throw new ArgumentOutOfRangeException("dueTime",Environment.GetResourceString("ArgumentOutOfRange_TimeoutTooLarge"));
            if (period > MAX_SUPPORTED_TIMEOUT)
                throw new ArgumentOutOfRangeException("period",Environment.GetResourceString("ArgumentOutOfRange_PeriodTooLarge"));
            StackCrawlMark stackMark = StackCrawlMark.LookForMyCaller; 
            TimerSetup(callback,state,(UInt32) dueTime, (UInt32) period,ref stackMark);
        } 
 
        public Timer(TimerCallback callback)
        { 
            int dueTime = -1;	// we want timer to be registered, but not activated.  Requires caller to call
            int period = -1;	// Change after a timer instance is created.  This is to avoid the potential
                                // for a timer to be fired before the returned value is assigned to the variable,
                                // potentially causing the callback to reference a bogus value (if passing the timer to the callback). 
 			
            StackCrawlMark stackMark = StackCrawlMark.LookForMyCaller; 
            TimerSetup(callback, this, (UInt32)dueTime, (UInt32)period, ref stackMark); 
        }
 
        private void TimerSetup(TimerCallback   callback,
                                                      Object          state,
                                                      UInt32      dueTime,
                                                      UInt32          period, 
                                                      ref StackCrawlMark  stackMark
                                                      ) 
        { 
            timerBase = new TimerBase();
            timerBase.AddTimer(callback, state,(UInt32) dueTime, (UInt32) period, ref stackMark); 
        }

        public bool Change(int dueTime, int period)
        { 
            if (dueTime < -1 )
                throw new ArgumentOutOfRangeException("dueTime",Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegOrNegative1")); 
            if (period < -1) 
                throw new ArgumentOutOfRangeException("period",Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegOrNegative1"));
 
            return timerBase.ChangeTimer((UInt32)dueTime,(UInt32)period);
        }

        public bool Change(TimeSpan dueTime, TimeSpan period) 
        {
            return Change((long) dueTime.TotalMilliseconds, (long) period.TotalMilliseconds); 
        } 

        [CLSCompliant(false)] 
        public bool Change(UInt32 dueTime, UInt32 period)
        {
            return timerBase.ChangeTimer(dueTime,period);
        } 

        public bool Change(long dueTime, long period) 
        { 
            if (dueTime < -1 )
                throw new ArgumentOutOfRangeException("dueTime", Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegOrNegative1")); 
            if (period < -1)
                throw new ArgumentOutOfRangeException("period", Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegOrNegative1"));
            if (dueTime > MAX_SUPPORTED_TIMEOUT)
                throw new ArgumentOutOfRangeException("dueTime", Environment.GetResourceString("ArgumentOutOfRange_TimeoutTooLarge")); 
            if (period > MAX_SUPPORTED_TIMEOUT)
                throw new ArgumentOutOfRangeException("period", Environment.GetResourceString("ArgumentOutOfRange_PeriodTooLarge")); 
 
            return timerBase.ChangeTimer((UInt32)dueTime,(UInt32)period);
        } 

        public bool Dispose(WaitHandle notifyObject)
        {
            if (notifyObject==null) 
                throw new ArgumentNullException("notifyObject");
            return timerBase.Dispose(notifyObject); 
        } 

 
        public void Dispose()
        {
            timerBase.Dispose();
        } 
    }
}

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