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Diffstat (limited to 'Rx/NET/Source/System.Reactive.Core/Reactive/Internal/SystemClock.cs')
| -rw-r--r-- | Rx/NET/Source/System.Reactive.Core/Reactive/Internal/SystemClock.cs | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/Rx/NET/Source/System.Reactive.Core/Reactive/Internal/SystemClock.cs b/Rx/NET/Source/System.Reactive.Core/Reactive/Internal/SystemClock.cs new file mode 100644 index 0000000..e482dd0 --- /dev/null +++ b/Rx/NET/Source/System.Reactive.Core/Reactive/Internal/SystemClock.cs @@ -0,0 +1,149 @@ +// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information. + +using System.ComponentModel; +using System.Threading; + +namespace System.Reactive.PlatformServices +{ + /// <summary> + /// (Infrastructure) Provides access to local system clock services. + /// </summary> + /// <remarks> + /// This type is used by the Rx infrastructure and not meant for public consumption or implementation. + /// No guarantees are made about forward compatibility of the type's functionality and its usage. + /// </remarks> + [EditorBrowsable(EditorBrowsableState.Never)] + public static class SystemClock + { + private static Lazy<ISystemClock> s_serviceSystemClock = new Lazy<ISystemClock>(InitializeSystemClock); + private static Lazy<INotifySystemClockChanged> s_serviceSystemClockChanged = new Lazy<INotifySystemClockChanged>(InitializeSystemClockChanged); + + private static int _refCount; + + /// <summary> + /// Gets the local system clock time. + /// </summary> + public static DateTimeOffset UtcNow + { + get { return s_serviceSystemClock.Value.UtcNow; } + } + + /// <summary> + /// Event that gets raised when a system clock change is detected, if there's any interest as indicated by AddRef calls. + /// </summary> + public static event EventHandler<SystemClockChangedEventArgs> SystemClockChanged; + + /// <summary> + /// Adds a reference to the system clock monitor, causing it to be sending notifications. + /// </summary> + /// <exception cref="NotSupportedException">Thrown when the system doesn't support sending clock change notifications.</exception> + public static void AddRef() + { + if (Interlocked.Increment(ref _refCount) == 1) + { + s_serviceSystemClockChanged.Value.SystemClockChanged += OnSystemClockChanged; + } + } + + /// <summary> + /// Removes a reference to the system clock monitor, causing it to stop sending notifications + /// if the removed reference was the last one. + /// </summary> + public static void Release() + { + if (Interlocked.Decrement(ref _refCount) == 0) + { + s_serviceSystemClockChanged.Value.SystemClockChanged -= OnSystemClockChanged; + } + } + + private static void OnSystemClockChanged(object sender, SystemClockChangedEventArgs e) + { + var scc = SystemClockChanged; + if (scc != null) + scc(sender, e); + } + + private static ISystemClock InitializeSystemClock() + { + return PlatformEnlightenmentProvider.Current.GetService<ISystemClock>() ?? new DefaultSystemClock(); + } + + private static INotifySystemClockChanged InitializeSystemClockChanged() + { + return PlatformEnlightenmentProvider.Current.GetService<INotifySystemClockChanged>() ?? new DefaultSystemClockMonitor(); + } + } + + /// <summary> + /// (Infrastructure) Provides access to the local system clock. + /// </summary> + /// <remarks> + /// This type is used by the Rx infrastructure and not meant for public consumption or implementation. + /// No guarantees are made about forward compatibility of the type's functionality and its usage. + /// </remarks> + [EditorBrowsable(EditorBrowsableState.Never)] + public interface ISystemClock + { + /// <summary> + /// Gets the current time. + /// </summary> + DateTimeOffset UtcNow { get; } + } + + /// <summary> + /// (Infrastructure) Provides a mechanism to notify local schedulers about system clock changes. + /// </summary> + /// <remarks> + /// This type is used by the Rx infrastructure and not meant for public consumption or implementation. + /// No guarantees are made about forward compatibility of the type's functionality and its usage. + /// </remarks> + [EditorBrowsable(EditorBrowsableState.Never)] + public interface INotifySystemClockChanged + { + /// <summary> + /// Event that gets raised when a system clock change is detected. + /// </summary> + event EventHandler<SystemClockChangedEventArgs> SystemClockChanged; + } + + /// <summary> + /// (Infrastructure) Event arguments for system clock change notifications. + /// </summary> + /// <remarks> + /// This type is used by the Rx infrastructure and not meant for public consumption or implementation. + /// No guarantees are made about forward compatibility of the type's functionality and its usage. + /// </remarks> + [EditorBrowsable(EditorBrowsableState.Never)] + public class SystemClockChangedEventArgs : EventArgs + { + /// <summary> + /// Creates a new system clock notification object with unknown old and new times. + /// </summary> + public SystemClockChangedEventArgs() + : this(DateTimeOffset.MinValue, DateTimeOffset.MaxValue) + { + } + + /// <summary> + /// Creates a new system clock notification object with the specified old and new times. + /// </summary> + /// <param name="oldTime">Time before the system clock changed, or DateTimeOffset.MinValue if not known.</param> + /// <param name="newTime">Time after the system clock changed, or DateTimeOffset.MaxValue if not known.</param> + public SystemClockChangedEventArgs(DateTimeOffset oldTime, DateTimeOffset newTime) + { + OldTime = oldTime; + NewTime = newTime; + } + + /// <summary> + /// Gets the time before the system clock changed, or DateTimeOffset.MinValue if not known. + /// </summary> + public DateTimeOffset OldTime { get; private set; } + + /// <summary> + /// Gets the time after the system clock changed, or DateTimeOffset.MaxValue if not known. + /// </summary> + public DateTimeOffset NewTime { get; private set; } + } +} |