Merge pull request #13767 from peppy/fix-realm-refresh-race

Fix thread safety of realm `Refresh` operation
This commit is contained in:
Dan Balasescu
2021-07-05 13:53:29 +09:00
committed by GitHub
3 changed files with 64 additions and 32 deletions

View File

@ -9,6 +9,7 @@ namespace osu.Game.Database
{
/// <summary>
/// The main realm context, bound to the update thread.
/// If querying from a non-update thread is needed, use <see cref="GetForRead"/> or <see cref="GetForWrite"/> to receive a context instead.
/// </summary>
Realm Context { get; }

View File

@ -2,8 +2,10 @@
// See the LICENCE file in the repository root for full licence text.
using System;
using System.Diagnostics;
using System.Threading;
using osu.Framework.Allocation;
using osu.Framework.Development;
using osu.Framework.Graphics;
using osu.Framework.Logging;
using osu.Framework.Platform;
@ -38,21 +40,29 @@ namespace osu.Game.Database
private static readonly GlobalStatistic<int> pending_writes = GlobalStatistics.Get<int>("Realm", "Pending writes");
private static readonly GlobalStatistic<int> active_usages = GlobalStatistics.Get<int>("Realm", "Active usages");
private readonly object updateContextLock = new object();
private Realm context;
public Realm Context
{
get
{
if (context == null)
if (!ThreadSafety.IsUpdateThread)
throw new InvalidOperationException($"Use {nameof(GetForRead)} or {nameof(GetForWrite)} when performing realm operations from a non-update thread");
lock (updateContextLock)
{
context = createContext();
Logger.Log($"Opened realm \"{context.Config.DatabasePath}\" at version {context.Config.SchemaVersion}");
if (context == null)
{
context = createContext();
Logger.Log($"Opened realm \"{context.Config.DatabasePath}\" at version {context.Config.SchemaVersion}");
}
// creating a context will ensure our schema is up-to-date and migrated.
return context;
}
// creating a context will ensure our schema is up-to-date and migrated.
return context;
}
}
@ -107,8 +117,11 @@ namespace osu.Game.Database
{
base.Update();
if (context?.Refresh() == true)
refreshes.Value++;
lock (updateContextLock)
{
if (context?.Refresh() == true)
refreshes.Value++;
}
}
private Realm createContext()
@ -154,9 +167,15 @@ namespace osu.Game.Database
private void flushContexts()
{
Logger.Log(@"Flushing realm contexts...", LoggingTarget.Database);
Debug.Assert(blockingLock.CurrentCount == 0);
var previousContext = context;
context = null;
Realm previousContext;
lock (updateContextLock)
{
previousContext = context;
context = null;
}
// wait for all threaded usages to finish
while (active_usages.Value > 0)