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author | Jiyoung Yun <jy910.yun@samsung.com> | 2017-04-13 14:17:19 +0900 |
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committer | Jiyoung Yun <jy910.yun@samsung.com> | 2017-04-13 14:17:19 +0900 |
commit | a56e30c8d33048216567753d9d3fefc2152af8ac (patch) | |
tree | 7e5d979695fc4a431740982eb1cfecc2898b23a5 /src/mscorlib/shared/System/Threading/LazyThreadSafetyMode.cs | |
parent | 4b11dc566a5bbfa1378d6266525c281b028abcc8 (diff) | |
download | coreclr-a56e30c8d33048216567753d9d3fefc2152af8ac.tar.gz coreclr-a56e30c8d33048216567753d9d3fefc2152af8ac.tar.bz2 coreclr-a56e30c8d33048216567753d9d3fefc2152af8ac.zip |
Imported Upstream version 2.0.0.11353upstream/2.0.0.11353
Diffstat (limited to 'src/mscorlib/shared/System/Threading/LazyThreadSafetyMode.cs')
-rw-r--r-- | src/mscorlib/shared/System/Threading/LazyThreadSafetyMode.cs | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/mscorlib/shared/System/Threading/LazyThreadSafetyMode.cs b/src/mscorlib/shared/System/Threading/LazyThreadSafetyMode.cs new file mode 100644 index 0000000000..2d13f23762 --- /dev/null +++ b/src/mscorlib/shared/System/Threading/LazyThreadSafetyMode.cs @@ -0,0 +1,44 @@ +// Licensed to the .NET Foundation under one or more agreements. +// The .NET Foundation licenses this file to you under the MIT license. +// See the LICENSE file in the project root for more information. + +// =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ +// +// a set of lightweight static helpers for lazy initialization. +// +// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- + +namespace System.Threading +{ + /// <summary> + /// Specifies how a <see cref="T:System.Threading.Lazy{T}"/> instance should synchronize access among multiple threads. + /// </summary> + public enum LazyThreadSafetyMode + { + /// <summary> + /// This mode makes no guarantees around the thread-safety of the <see cref="T:System.Threading.Lazy{T}"/> instance. If used from multiple threads, the behavior of the <see cref="T:System.Threading.Lazy{T}"/> is undefined. + /// This mode should be used when a <see cref="T:System.Threading.Lazy{T}"/> is guaranteed to never be initialized from more than one thread simultaneously and high performance is crucial. + /// If valueFactory throws an exception when the <see cref="T:System.Threading.Lazy{T}"/> is initialized, the exception will be cached and returned on subsequent accesses to Value. Also, if valueFactory recursively + /// accesses Value on this <see cref="T:System.Threading.Lazy{T}"/> instance, a <see cref="T:System.InvalidOperationException"/> will be thrown. + /// </summary> + None, + + /// <summary> + /// When multiple threads attempt to simultaneously initialize a <see cref="T:System.Threading.Lazy{T}"/> instance, this mode allows each thread to execute the + /// valueFactory but only the first thread to complete initialization will be allowed to set the final value of the <see cref="T:System.Threading.Lazy{T}"/>. + /// Once initialized successfully, any future calls to Value will return the cached result. If valueFactory throws an exception on any thread, that exception will be + /// propagated out of Value. If any thread executes valueFactory without throwing an exception and, therefore, successfully sets the value, that value will be returned on + /// subsequent accesses to Value from any thread. If no thread succeeds in setting the value, IsValueCreated will remain false and subsequent accesses to Value will result in + /// the valueFactory delegate re-executing. Also, if valueFactory recursively accesses Value on this <see cref="T:System.Threading.Lazy{T}"/> instance, an exception will NOT be thrown. + /// </summary> + PublicationOnly, + + /// <summary> + /// This mode uses locks to ensure that only a single thread can initialize a <see cref="T:System.Threading.Lazy{T}"/> instance in a thread-safe manner. In general, + /// taken if this mode is used in conjunction with a <see cref="T:System.Threading.Lazy{T}"/> valueFactory delegate that uses locks internally, a deadlock can occur if not + /// handled carefully. If valueFactory throws an exception when the<see cref="T:System.Threading.Lazy{T}"/> is initialized, the exception will be cached and returned on + /// subsequent accesses to Value. Also, if valueFactory recursively accesses Value on this <see cref="T:System.Threading.Lazy{T}"/> instance, a <see cref="T:System.InvalidOperationException"/> will be thrown. + /// </summary> + ExecutionAndPublication + } +} |