| | | 1 | | // Licensed to the .NET Foundation under one or more agreements. |
| | | 2 | | // The .NET Foundation licenses this file to you under the MIT license. |
| | | 3 | | |
| | | 4 | | using System; |
| | | 5 | | using System.Collections.Concurrent; |
| | | 6 | | using System.Threading; |
| | | 7 | | |
| | | 8 | | namespace CoreWCF.Runtime |
| | | 9 | | { |
| | | 10 | | internal struct TimeoutHelper |
| | | 11 | | { |
| | | 12 | | // This is a brief plan on how to recover original timeout from CancellationToken |
| | | 13 | | // The coalescing is needed to prevent hammering at the timer queue otherwise we |
| | | 14 | | // get a lot of contention on it. It's really only the timer that needs to be coalesced. |
| | | 15 | | // 1. Change the coalescing to keep track of IOThreadTimer object |
| | | 16 | | // 2. Create a class which derives from/encapsulates an IOThreadTimer which can be used to |
| | | 17 | | // register CancellationTokenSource objects to call cancel when the timer fires. This |
| | | 18 | | // is the class that we coalesce. |
| | | 19 | | // 3. Create RecoverableTimeoutCancellationTokenSource which derives from Cancellation token source. |
| | | 20 | | // It has the following behavior: |
| | | 21 | | // a. Takes the derived IOThreadTimer from (2) in the constructor and registers cancelling itself |
| | | 22 | | // when the timer fires. |
| | | 23 | | // b. Takes the requested timeout in the constructor and saves it. |
| | | 24 | | // c. Override the GetHashCode method to return a value representing the original timeout value. |
| | | 25 | | // CancellationToken defers to the owning CancellationTokenSource to implement GetHashCode() |
| | | 26 | | // 4. Add a TimeoutHelper method which returns a TimeSpan from a CancellationToken. It queries the |
| | | 27 | | // GetHashCode method to get the original requested timeout. |
| | | 28 | | public static readonly TimeSpan MaxWait = TimeSpan.FromMilliseconds(int.MaxValue); |
| | | 29 | | private static readonly CancellationToken s_precancelledToken = new CancellationToken(true); |
| | | 30 | | |
| | | 31 | | private bool _cancellationTokenInitialized; |
| | | 32 | | private bool _deadlineSet; |
| | | 33 | | |
| | | 34 | | private CancellationToken _cancellationToken; |
| | | 35 | | private DateTime _deadline; |
| | | 36 | | private TimeSpan _originalTimeout; |
| | | 37 | | |
| | | 38 | | public TimeoutHelper(TimeSpan timeout) |
| | | 39 | | { |
| | | 40 | | Fx.Assert(timeout >= TimeSpan.Zero || timeout == Timeout.InfiniteTimeSpan, |
| | | 41 | | $"timeout must be non-negative or {Timeout.InfiniteTimeSpan}"); |
| | | 42 | | |
| | | 43 | | _cancellationToken = default; |
| | | 44 | | _cancellationTokenInitialized = false; |
| | | 45 | | _originalTimeout = timeout; |
| | | 46 | | _deadline = DateTime.MaxValue; |
| | | 47 | | _deadlineSet = (timeout == TimeSpan.MaxValue || timeout == Timeout.InfiniteTimeSpan); |
| | | 48 | | } |
| | | 49 | | |
| | | 50 | | public CancellationToken GetCancellationToken() |
| | | 51 | | { |
| | | 52 | | if (!_cancellationTokenInitialized) |
| | | 53 | | { |
| | | 54 | | TimeSpan timeout = RemainingTime(); |
| | | 55 | | if (timeout >= MaxWait || timeout == Timeout.InfiniteTimeSpan) |
| | | 56 | | { |
| | | 57 | | _cancellationToken = CancellationToken.None; |
| | | 58 | | } |
| | | 59 | | else if (timeout > TimeSpan.Zero) |
| | | 60 | | { |
| | | 61 | | _cancellationToken = TimeoutTokenSource.FromTimeout((int)timeout.TotalMilliseconds); |
| | | 62 | | } |
| | | 63 | | else |
| | | 64 | | { |
| | | 65 | | _cancellationToken = s_precancelledToken; |
| | | 66 | | } |
| | | 67 | | _cancellationTokenInitialized = true; |
| | | 68 | | } |
| | | 69 | | |
| | | 70 | | return _cancellationToken; |
| | | 71 | | } |
| | | 72 | | |
| | | 73 | | |
| | | 74 | | public TimeSpan OriginalTimeout |
| | | 75 | | { |
| | | 76 | | get { return _originalTimeout; } |
| | | 77 | | } |
| | | 78 | | |
| | | 79 | | public static bool IsTooLarge(TimeSpan timeout) |
| | | 80 | | { |
| | | 81 | | return (timeout > MaxWait) && (timeout != TimeSpan.MaxValue); |
| | | 82 | | } |
| | | 83 | | |
| | | 84 | | public static TimeSpan FromMilliseconds(int milliseconds) |
| | | 85 | | { |
| | | 86 | | if (milliseconds == Timeout.Infinite) |
| | | 87 | | { |
| | | 88 | | return TimeSpan.MaxValue; |
| | | 89 | | } |
| | | 90 | | else |
| | | 91 | | { |
| | | 92 | | return TimeSpan.FromMilliseconds(milliseconds); |
| | | 93 | | } |
| | | 94 | | } |
| | | 95 | | |
| | | 96 | | public static int ToMilliseconds(TimeSpan timeout) |
| | | 97 | | { |
| | | 98 | | if (timeout == TimeSpan.MaxValue) |
| | | 99 | | { |
| | | 100 | | return Timeout.Infinite; |
| | | 101 | | } |
| | | 102 | | else |
| | | 103 | | { |
| | | 104 | | long ticks = Ticks.FromTimeSpan(timeout); |
| | | 105 | | if (ticks / TimeSpan.TicksPerMillisecond > int.MaxValue) |
| | | 106 | | { |
| | | 107 | | return int.MaxValue; |
| | | 108 | | } |
| | | 109 | | return Ticks.ToMilliseconds(ticks); |
| | | 110 | | } |
| | | 111 | | } |
| | | 112 | | |
| | | 113 | | public static TimeSpan Min(TimeSpan val1, TimeSpan val2) |
| | | 114 | | { |
| | | 115 | | if (val1 > val2) |
| | | 116 | | { |
| | | 117 | | return val2; |
| | | 118 | | } |
| | | 119 | | else |
| | | 120 | | { |
| | | 121 | | return val1; |
| | | 122 | | } |
| | | 123 | | } |
| | | 124 | | |
| | | 125 | | public static TimeSpan Add(TimeSpan timeout1, TimeSpan timeout2) |
| | | 126 | | { |
| | | 127 | | return Ticks.ToTimeSpan(Ticks.Add(Ticks.FromTimeSpan(timeout1), Ticks.FromTimeSpan(timeout2))); |
| | | 128 | | } |
| | | 129 | | |
| | | 130 | | public static DateTime Add(DateTime time, TimeSpan timeout) |
| | | 131 | | { |
| | | 132 | | if (timeout >= TimeSpan.Zero && DateTime.MaxValue - time <= timeout) |
| | | 133 | | { |
| | | 134 | | return DateTime.MaxValue; |
| | | 135 | | } |
| | | 136 | | if (timeout <= TimeSpan.Zero && DateTime.MinValue - time >= timeout) |
| | | 137 | | { |
| | | 138 | | return DateTime.MinValue; |
| | | 139 | | } |
| | | 140 | | return time + timeout; |
| | | 141 | | } |
| | | 142 | | |
| | | 143 | | public static DateTime Subtract(DateTime time, TimeSpan timeout) |
| | | 144 | | { |
| | | 145 | | return Add(time, TimeSpan.Zero - timeout); |
| | | 146 | | } |
| | | 147 | | |
| | | 148 | | public static TimeSpan Divide(TimeSpan timeout, int factor) |
| | | 149 | | { |
| | | 150 | | if (timeout == TimeSpan.MaxValue) |
| | | 151 | | { |
| | | 152 | | return TimeSpan.MaxValue; |
| | | 153 | | } |
| | | 154 | | |
| | | 155 | | return Ticks.ToTimeSpan((Ticks.FromTimeSpan(timeout) / factor) + 1); |
| | | 156 | | } |
| | | 157 | | |
| | | 158 | | public TimeSpan RemainingTime() |
| | | 159 | | { |
| | | 160 | | if (!_deadlineSet) |
| | | 161 | | { |
| | | 162 | | SetDeadline(); |
| | | 163 | | return _originalTimeout; |
| | | 164 | | } |
| | | 165 | | else if (_deadline == DateTime.MaxValue) |
| | | 166 | | { |
| | | 167 | | return TimeSpan.MaxValue; |
| | | 168 | | } |
| | | 169 | | else |
| | | 170 | | { |
| | | 171 | | TimeSpan remaining = _deadline - DateTime.UtcNow; |
| | | 172 | | if (remaining <= TimeSpan.Zero) |
| | | 173 | | { |
| | | 174 | | return TimeSpan.Zero; |
| | | 175 | | } |
| | | 176 | | else |
| | | 177 | | { |
| | | 178 | | return remaining; |
| | | 179 | | } |
| | | 180 | | } |
| | | 181 | | } |
| | | 182 | | |
| | | 183 | | public TimeSpan ElapsedTime() |
| | | 184 | | { |
| | | 185 | | return _originalTimeout - RemainingTime(); |
| | | 186 | | } |
| | | 187 | | |
| | | 188 | | private void SetDeadline() |
| | | 189 | | { |
| | | 190 | | Fx.Assert(!_deadlineSet, "TimeoutHelper deadline set twice."); |
| | | 191 | | _deadline = DateTime.UtcNow + _originalTimeout; |
| | | 192 | | _deadlineSet = true; |
| | | 193 | | } |
| | | 194 | | |
| | | 195 | | public static TimeSpan GetOriginalTimeout(CancellationToken token) |
| | | 196 | | { |
| | | 197 | | return RecoverableTimeoutCancellationTokenSource.GetOriginalTimeout(token); |
| | | 198 | | } |
| | | 199 | | |
| | | 200 | | public static void ThrowIfNegativeArgument(TimeSpan timeout) |
| | | 201 | | { |
| | | 202 | | ThrowIfNegativeArgument(timeout, "timeout"); |
| | | 203 | | } |
| | | 204 | | |
| | | 205 | | public static void ThrowIfNegativeArgument(TimeSpan timeout, string argumentName) |
| | | 206 | | { |
| | | 207 | | if (timeout < TimeSpan.Zero) |
| | | 208 | | { |
| | | 209 | | throw Fx.Exception.ArgumentOutOfRange(argumentName, timeout, SRCommon.Format(SRCommon.TimeoutMustBeNonNe |
| | | 210 | | } |
| | | 211 | | } |
| | | 212 | | |
| | | 213 | | public static void ThrowIfNonPositiveArgument(TimeSpan timeout) |
| | | 214 | | { |
| | | 215 | | ThrowIfNonPositiveArgument(timeout, "timeout"); |
| | | 216 | | } |
| | | 217 | | |
| | | 218 | | public static void ThrowIfNonPositiveArgument(TimeSpan timeout, string argumentName) |
| | | 219 | | { |
| | | 220 | | if (timeout <= TimeSpan.Zero) |
| | | 221 | | { |
| | | 222 | | throw Fx.Exception.ArgumentOutOfRange(argumentName, timeout, SRCommon.Format(SRCommon.TimeoutMustBePosit |
| | | 223 | | } |
| | | 224 | | } |
| | | 225 | | |
| | | 226 | | public static bool WaitOne(WaitHandle waitHandle, TimeSpan timeout) |
| | | 227 | | { |
| | | 228 | | ThrowIfNegativeArgument(timeout); |
| | | 229 | | if (timeout == TimeSpan.MaxValue) |
| | | 230 | | { |
| | | 231 | | waitHandle.WaitOne(); |
| | | 232 | | return true; |
| | | 233 | | } |
| | | 234 | | else |
| | | 235 | | { |
| | | 236 | | // http://msdn.microsoft.com/en-us/library/85bbbxt9(v=vs.110).aspx |
| | | 237 | | // with exitContext was used in Desktop which is not supported in Net Native or CoreClr |
| | | 238 | | return waitHandle.WaitOne(timeout); |
| | | 239 | | } |
| | | 240 | | } |
| | | 241 | | |
| | | 242 | | internal static TimeoutException CreateEnterTimedOutException(TimeSpan timeout) |
| | | 243 | | { |
| | | 244 | | return new TimeoutException(SRCommon.Format(SRCommon.LockTimeoutExceptionMessage, timeout)); |
| | | 245 | | } |
| | | 246 | | } |
| | | 247 | | |
| | | 248 | | /// <summary> |
| | | 249 | | /// This class coalesces timeout tokens because cancelation tokens with timeouts are more expensive to expose. |
| | | 250 | | /// Disposing too many such tokens will cause thread contentions in high throughput scenario. |
| | | 251 | | /// |
| | | 252 | | /// Tokens with target cancelation time 15ms apart would resolve to the same instance. |
| | | 253 | | /// </summary> |
| | | 254 | | internal static class TimeoutTokenSource |
| | | 255 | | { |
| | | 256 | | /// <summary> |
| | | 257 | | /// These are constants use to calculate timeout coalescing, for more description see method FromTimeoutAsync |
| | | 258 | | /// </summary> |
| | | 259 | | private const int CoalescingFactor = 15; |
| | | 260 | | private const int GranularityFactor = 2000; |
| | | 261 | | private const int SegmentationFactor = CoalescingFactor * GranularityFactor; |
| | | 262 | | |
| | 0 | 263 | | private static readonly ConcurrentDictionary<long, CancellationTokenSourceIOThreadTimer> s_timerCache = |
| | 0 | 264 | | new ConcurrentDictionary<long, CancellationTokenSourceIOThreadTimer>(); |
| | | 265 | | |
| | 0 | 266 | | private static readonly Action<object> s_deregisterTimer = (object state) => |
| | 0 | 267 | | { |
| | 0 | 268 | | long targetTime = (long)state; |
| | 0 | 269 | | s_timerCache.TryRemove(targetTime, out CancellationTokenSourceIOThreadTimer ignored); |
| | 0 | 270 | | }; |
| | | 271 | | |
| | | 272 | | public static CancellationToken FromTimeout(int millisecondsTimeout) |
| | | 273 | | { |
| | | 274 | | // Note that CancellationTokenSource constructor requires input to be >= -1, |
| | | 275 | | // restricting millisecondsTimeout to be >= -1 would enforce that |
| | 0 | 276 | | if (millisecondsTimeout < -1) |
| | | 277 | | { |
| | 0 | 278 | | throw new ArgumentOutOfRangeException("Invalid millisecondsTimeout value " + millisecondsTimeout); |
| | | 279 | | } |
| | | 280 | | |
| | | 281 | | // To prevent s_tokenCache growing too large, we have to adjust the granularity of the our coalesce dependin |
| | | 282 | | // on the value of millisecondsTimeout. The coalescing span scales proportionally with millisecondsTimeout w |
| | | 283 | | // would guarantee constant s_tokenCache size in the case where similar millisecondsTimeout values are accep |
| | | 284 | | // If the method is given a wildly different millisecondsTimeout values all the time, the dictionary would s |
| | | 285 | | // only grow logarithmically with respect to the range of the input values |
| | | 286 | | |
| | 0 | 287 | | uint currentTime = (uint)Environment.TickCount; |
| | 0 | 288 | | long targetTime = millisecondsTimeout + currentTime; |
| | | 289 | | |
| | | 290 | | // Formula for our coalescing span: |
| | | 291 | | // Divide millisecondsTimeout by SegmentationFactor and take the highest bit and then multiply CoalescingFac |
| | 0 | 292 | | int segmentValue = millisecondsTimeout / SegmentationFactor; |
| | 0 | 293 | | int coalescingSpanMs = CoalescingFactor; |
| | 0 | 294 | | while (segmentValue > 0) |
| | | 295 | | { |
| | 0 | 296 | | segmentValue >>= 1; |
| | 0 | 297 | | coalescingSpanMs <<= 1; |
| | | 298 | | } |
| | 0 | 299 | | targetTime = ((targetTime + (coalescingSpanMs - 1)) / coalescingSpanMs) * coalescingSpanMs; |
| | | 300 | | |
| | 0 | 301 | | if (!s_timerCache.TryGetValue(targetTime, out CancellationTokenSourceIOThreadTimer ctsTimer)) |
| | | 302 | | { |
| | 0 | 303 | | ctsTimer = new CancellationTokenSourceIOThreadTimer(); |
| | | 304 | | |
| | | 305 | | // only a single thread may succeed adding its timer into the cache |
| | 0 | 306 | | if (s_timerCache.TryAdd(targetTime, ctsTimer)) |
| | | 307 | | { |
| | | 308 | | // Clean up cache when timer fires |
| | 0 | 309 | | ctsTimer.SetCompletionCallback(s_deregisterTimer, targetTime); |
| | 0 | 310 | | ctsTimer.Set((int)(targetTime - currentTime)); |
| | | 311 | | } |
| | | 312 | | else |
| | | 313 | | { |
| | | 314 | | // for threads that failed when calling TryAdd, there should be one already in the cache |
| | 0 | 315 | | if (!s_timerCache.TryGetValue(targetTime, out ctsTimer)) |
| | | 316 | | { |
| | | 317 | | // In unlikely scenario the timer has already fired, we would not find it in cache. |
| | | 318 | | // In this case we would simply create a CTS which doesn't use the coalesced timer. |
| | 0 | 319 | | var cts = new RecoverableTimeoutCancellationTokenSource(millisecondsTimeout); |
| | 0 | 320 | | cts.CancelAfter(millisecondsTimeout); |
| | 0 | 321 | | return cts.Token; |
| | | 322 | | } |
| | | 323 | | } |
| | | 324 | | } |
| | | 325 | | |
| | 0 | 326 | | var tokenSource = new RecoverableTimeoutCancellationTokenSource(millisecondsTimeout); |
| | 0 | 327 | | ctsTimer.RegisterTokenSourceForCancellation(tokenSource); |
| | 0 | 328 | | return tokenSource.Token; |
| | | 329 | | } |
| | | 330 | | } |
| | | 331 | | } |