MemoryCache Evict Bug - Added item is evicted when capacity is hit
#42,624 建立於 2020年9月23日
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描述
Describe the bug
When we have a limit to the MemoryCache, its Evict logic does not behavior as expected This is a bug we found in community Why do I need to call twice the Set on my size limited MemoryCache when I hit the size limit?, the replier of this thread helped build a reproduce sample
To Reproduce
the below code can reproduce this issue
class Program
{
private static MemoryCache _cache;
private static MemoryCacheEntryOptions _options;
static void Main(string[] args)
{
_cache = new MemoryCache(new MemoryCacheOptions
{
SizeLimit = 2
});
_options = new MemoryCacheEntryOptions
{
Size = 1
};
_options.PostEvictionCallbacks.Add(new PostEvictionCallbackRegistration
{
EvictionCallback = (key, value, reason, state) =>
{
if (reason == EvictionReason.Capacity)
{
Console.WriteLine($"Evicting '{key}' for capacity");
}
}
});
Console.WriteLine(TestCache("first"));
Console.WriteLine(TestCache("second"));
Console.WriteLine(TestCache("third")); // starts compaction
Thread.Sleep(1000);
Console.WriteLine(TestCache("third"));
Console.WriteLine(TestCache("third")); // now from cache
}
private static object TestCache(string id)
{
if (_cache.TryGetValue(id, out var cachedEntry))
{
return cachedEntry;
}
_cache.Set(id, $"{id} - cached", _options);
return id;
}
}
Expected result should be
first
second
Evicting 'first' for capacity
third
third - cached
The actual result is
first
second
third
Evicting 'third' for capacity
Evicting 'first' for capacity
third
third - cached
Exceptions (if any)
Further technical details
- ASP.NET Core version 3.1
- Include the output of
dotnet --info.NET Core SDK (reflecting any global.json): Version: 3.1.402 Commit: 9b5de826fd
Runtime Environment: OS Name: Windows OS Version: 10.0.19042 OS Platform: Windows RID: win10-x64 Base Path: C:\Program Files\dotnet\sdk\3.1.402\
Host (useful for support): Version: 3.1.8 Commit: 9c1330dedd
.NET Core SDKs installed: 2.1.202 [C:\Program Files\dotnet\sdk] 2.1.504 [C:\Program Files\dotnet\sdk] 2.1.505 [C:\Program Files\dotnet\sdk] 2.1.507 [C:\Program Files\dotnet\sdk] 2.1.508 [C:\Program Files\dotnet\sdk] 2.1.509 [C:\Program Files\dotnet\sdk] 2.1.511 [C:\Program Files\dotnet\sdk] 2.1.602 [C:\Program Files\dotnet\sdk] 2.1.700 [C:\Program Files\dotnet\sdk] 2.2.108 [C:\Program Files\dotnet\sdk] 2.2.300 [C:\Program Files\dotnet\sdk] 3.0.100 [C:\Program Files\dotnet\sdk] 3.1.402 [C:\Program Files\dotnet\sdk]
.NET Core runtimes installed: Microsoft.AspNetCore.All 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.1.22 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.2.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.App 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.1.22 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.2.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 3.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 3.0.1-dev [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 3.0.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 3.1.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.NETCore.App 1.0.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.0.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.22 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.2.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 3.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 3.1.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.WindowsDesktop.App 3.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 3.1.8 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
- The IDE (VS / VS Code/ VS4Mac) you're running on, and it's version VS 2019 16.7.3