7bb601b5d7
* Modify rule S2551: clarify example in description * Modify rule S2551: improve word choice
49 lines
1.5 KiB
Plaintext
49 lines
1.5 KiB
Plaintext
include::../why-dotnet.adoc[]
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For example, a `string` should never be used for locking. When a `string` is https://en.wikipedia.org/wiki/Interning_(computer_science)[interned] by the runtime, it can be shared by multiple threads, breaking the locking mechanism.
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Instead, a dedicated private `object` instance should be used for each shared resource. This minimizes access to the lock instance, avoiding deadlocks and lock contention.
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The following objects are considered as shared resources:
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* a reference to https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/this[this]: if the instance is publicly accessibly, the lock might be shared
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* a https://learn.microsoft.com/en-us/dotnet/api/system.type[Type] object: if the type class is publicly accessibly, the lock might be shared
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* a https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/strings/[string] literal or instance: if any other part of the program uses the same string, the lock is shared because of interning
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== How to fix it
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=== Code examples
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==== Noncompliant code example
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[source,csharp,diff-id=1,diff-type=noncompliant]
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----
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void MyLockingMethod()
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{
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lock (this) // Noncompliant
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{
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// ...
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}
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}
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----
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==== Compliant solution
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[source,csharp,diff-id=1,diff-type=compliant]
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----
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private readonly object lockObj = new object();
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void MyLockingMethod()
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{
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lock (lockObj)
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{
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// ...
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}
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}
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----
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include::../resources-dotnet.adoc[]
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include::../rspecator.adoc[]
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