32 lines
2.1 KiB
Plaintext
32 lines
2.1 KiB
Plaintext
== Why is this an issue?
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https://learn.microsoft.com/en-us/dotnet/api/system.gc.collect[GC.Collect] is a method that forces or suggests to the https://learn.microsoft.com/en-us/dotnet/standard/garbage-collection/[garbage collector] to run a collection of objects in the managed heap that are no longer being used and free their memory.
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Calling `GC.Collect` is rarely necessary and can significantly affect application performance. That's because it is a https://en.wikipedia.org/wiki/Tracing_garbage_collection[tracing garbage collector] and needs to examine _every object in memory_ for cleanup and analyze all reachable objects from every application's root (static fields, local variables on thread stacks, etc.).
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To perform tracing and memory releasing correctly, the garbage collection https://learn.microsoft.com/en-us/dotnet/standard/garbage-collection/latency[may] need to block all threads currently in execution. That is why, as a general rule, the https://learn.microsoft.com/en-us/dotnet/standard/garbage-collection/performance#troubleshoot-performance-issues[performance implications] of calling `GC.Collect` far outweigh the benefits.
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This rule raises an issue when any overload of `Collect` is invoked.
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[source,csharp]
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----
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static void Main(string[] args)
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{
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// ...
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GC.Collect(); // Noncompliant
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GC.Collect(2, GCCollectionMode.Optimized); // Noncompliant
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}
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----
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There may be exceptions to this rule: for example, you've just triggered some event that is unique in the run of your program that caused a lot of long-lived objects to die, and you want to release their memory.
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== Resources
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=== Documentation
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* https://learn.microsoft.com/en-us/dotnet/standard/garbage-collection/[Garbage collection]
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* https://learn.microsoft.com/en-us/dotnet/api/system.gc.collect[GC.Collect]
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* https://learn.microsoft.com/en-us/dotnet/standard/garbage-collection/latency[Garbage collection latency modes]
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* https://learn.microsoft.com/en-us/dotnet/standard/garbage-collection/performance#troubleshoot-performance-issues[Garbage collection troubleshoot performance issues]
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include::rspecator.adoc[] |