Fix a hang during the loading stage

In KAddressArbiter, threads were originally inserted into the wait queue according to their DynamicPriority.

When multiple threads had the same DynamicPriority, the original implementation could not guarantee their existing order. Threads with the same dynamic priority are now inserted in FIFO order, preventing unstable wake-up ordering from blocking the guest synchronization flow.
This commit is contained in:
avan
2026-09-08 15:54:22 -05:00
committed by KeatonTheBot
parent e07f333a31
commit ef14467d1f
@@ -15,7 +15,6 @@ namespace Ryujinx.HLE.HOS.Kernel.Threading
private readonly Dictionary<ulong, List<KThread>> _condVarThreads;
private readonly Dictionary<ulong, List<KThread>> _arbiterThreads;
private readonly ByDynamicPriority _byDynamicPriority;
public KAddressArbiter(KernelContext context)
{
@@ -23,7 +22,6 @@ namespace Ryujinx.HLE.HOS.Kernel.Threading
_condVarThreads = [];
_arbiterThreads = [];
_byDynamicPriority = new ByDynamicPriority();
}
public Result ArbitrateLock(int ownerHandle, ulong mutexAddress, int requesterHandle)
@@ -142,14 +140,9 @@ namespace Ryujinx.HLE.HOS.Kernel.Threading
if (_condVarThreads.TryGetValue(condVarAddress, out List<KThread> threads))
{
int i = 0;
int i = FindDynamicPriorityFifoInsertionIndex(threads, currentThread);
if (threads.Count > 0)
{
i = threads.BinarySearch(currentThread, _byDynamicPriority);
if (i < 0) i = ~i;
}
threads.Insert(i, currentThread);
}
else
@@ -332,14 +325,9 @@ namespace Ryujinx.HLE.HOS.Kernel.Threading
if (_arbiterThreads.TryGetValue(address, out List<KThread> threads))
{
int i = 0;
int i = FindDynamicPriorityFifoInsertionIndex(threads, currentThread);
if (threads.Count > 0)
{
i = threads.BinarySearch(currentThread, _byDynamicPriority);
if (i < 0) i = ~i;
}
threads.Insert(i, currentThread);
}
else
@@ -424,14 +412,9 @@ namespace Ryujinx.HLE.HOS.Kernel.Threading
if (_arbiterThreads.TryGetValue(address, out List<KThread> threads))
{
int i = 0;
int i = FindDynamicPriorityFifoInsertionIndex(threads, currentThread);
if (threads.Count > 0)
{
i = threads.BinarySearch(currentThread, _byDynamicPriority);
if (i < 0) i = ~i;
}
threads.Insert(i, currentThread);
}
else
@@ -627,12 +610,28 @@ namespace Ryujinx.HLE.HOS.Kernel.Threading
return validCount;
}
private class ByDynamicPriority : IComparer<KThread>
private static int FindDynamicPriorityFifoInsertionIndex(List<KThread> threads, KThread currentThread)
{
public int Compare(KThread x, KThread y)
int low = 0;
int high = threads.Count;
// Lower numeric values represent higher priorities. Use upper-bound insertion
// to preserve FIFO order among waiters with the same dynamic priority.
while (low < high)
{
return x!.DynamicPriority.CompareTo(y!.DynamicPriority);
int middle = low + ((high - low) >> 1);
if (threads[middle].DynamicPriority <= currentThread.DynamicPriority)
{
low = middle + 1;
}
else
{
high = middle;
}
}
return low;
}
}
}