[kernel] Guest-thread blocking for pthread_mutex_lock is currently disabled

src/SharpEmu.Libs/Kernel/KernelAprCompatExports.cs

@@ -11,8 +11,13 @@ namespace SharpEmu.Libs.Kernel;
 
 public static class KernelAprCompatExports
 {
-    private static readonly ConcurrentDictionary<uint, ulong> _submittedCommandBuffers = new();
+    private static readonly ConcurrentDictionary<uint, AprSubmission> _submittedCommandBuffers = new();
     private static int _nextSubmissionId;
+    private static int _aprWaitTraceCount;
+    private static readonly bool _traceApr =
+        string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_AMPR"), "1", StringComparison.Ordinal);
+
+    private readonly record struct AprSubmission(ulong CommandBuffer, ulong Priority, ulong ResultAddress);
 
     [SysAbiExport(
         Nid = "ASoW5WE-UPo",
@@ -37,7 +42,7 @@ public static class KernelAprCompatExports
             submissionId = unchecked((uint)Interlocked.Increment(ref _nextSubmissionId));
         }
 
-        _submittedCommandBuffers[submissionId] = commandBuffer;
+        _submittedCommandBuffers[submissionId] = new AprSubmission(commandBuffer, priority, resultAddress);
 
         var completionResult = AmprExports.CompleteCommandBuffer(ctx, commandBuffer);
         if (completionResult != (int)OrbisGen2Result.ORBIS_GEN2_OK)
@@ -67,20 +72,23 @@ public static class KernelAprCompatExports
     public static int KernelAprWaitCommandBuffer(CpuContext ctx)
     {
         var submissionId = unchecked((uint)ctx[CpuRegister.Rdi]);
-        var priority = ctx[CpuRegister.Rsi];
+        var waitArg1 = ctx[CpuRegister.Rsi];
-        var resultAddress = ctx[CpuRegister.Rdx];
+        var waitArg2 = ctx[CpuRegister.Rdx];
 
-        if (!_submittedCommandBuffers.TryRemove(submissionId, out var commandBuffer))
+        if (!_submittedCommandBuffers.TryRemove(submissionId, out var submission))
         {
+            TraceAprWaitFailure(ctx, "wait_missing", submissionId, commandBuffer: 0, waitArg1, waitArg2);
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
         }
 
+        var resultAddress = ResolveWaitResultAddress(waitArg1, waitArg2, submission.ResultAddress);
         if (resultAddress != 0 && !TryWriteAprResult(ctx, resultAddress))
         {
+            TraceAprWaitFailure(ctx, "wait_result_fault", submissionId, submission.CommandBuffer, waitArg1, waitArg2);
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
 
-        TraceApr(ctx, "wait", submissionId, commandBuffer, priority, resultAddress);
+        TraceApr(ctx, "wait", submissionId, submission.CommandBuffer, waitArg1, resultAddress);
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
@@ -98,7 +106,7 @@ public static class KernelAprCompatExports
         }
 
         var submissionId = unchecked((uint)Interlocked.Increment(ref _nextSubmissionId));
-        _submittedCommandBuffers[submissionId] = commandBuffer;
+        _submittedCommandBuffers[submissionId] = new AprSubmission(commandBuffer, ctx[CpuRegister.Rsi], ResultAddress: 0);
 
         var completionResult = AmprExports.CompleteCommandBuffer(ctx, commandBuffer);
         if (completionResult != (int)OrbisGen2Result.ORBIS_GEN2_OK)
@@ -125,7 +133,7 @@ public static class KernelAprCompatExports
         }
 
         var submissionId = unchecked((uint)Interlocked.Increment(ref _nextSubmissionId));
-        _submittedCommandBuffers[submissionId] = commandBuffer;
+        _submittedCommandBuffers[submissionId] = new AprSubmission(commandBuffer, ctx[CpuRegister.Rsi], ResultAddress: 0);
 
         var completionResult = AmprExports.CompleteCommandBuffer(ctx, commandBuffer);
         if (completionResult != (int)OrbisGen2Result.ORBIS_GEN2_OK)
@@ -149,6 +157,27 @@ public static class KernelAprCompatExports
         return ctx.Memory.TryWrite(resultAddress, result);
     }
 
+    private static ulong ResolveWaitResultAddress(ulong waitArg1, ulong waitArg2, ulong submittedResultAddress)
+    {
+        if (waitArg2 == 0)
+        {
+            return submittedResultAddress;
+        }
+
+        if (IsAmprCompletionToken(waitArg1) && waitArg2 <= 0xFFFF)
+        {
+            return submittedResultAddress;
+        }
+
+        return waitArg2;
+    }
+
+    private static bool IsAmprCompletionToken(ulong value)
+    {
+        var tag = value >> 56;
+        return tag is 0x0C or 0x10;
+    }
+
     private static bool TryWriteUInt32(CpuContext ctx, ulong address, uint value)
     {
         Span<byte> buffer = stackalloc byte[sizeof(uint)];
@@ -164,7 +193,7 @@ public static class KernelAprCompatExports
         ulong priority,
         ulong aux)
     {
-        if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_AMPR"), "1", StringComparison.Ordinal))
+        if (!_traceApr)
         {
             return;
         }
@@ -181,4 +210,46 @@ public static class KernelAprCompatExports
                 $"[LOADER][TRACE] apr.{operation}.result: addr=0x{aux:X16} q0=0x{result0:X16} q1=0x{result1:X16}");
         }
     }
+
+    private static void TraceAprWaitFailure(
+        CpuContext ctx,
+        string operation,
+        uint submissionId,
+        ulong commandBuffer,
+        ulong priority,
+        ulong resultAddress)
+    {
+        if (!_traceApr)
+        {
+            return;
+        }
+
+        var traceCount = Interlocked.Increment(ref _aprWaitTraceCount);
+        if (traceCount > 32 && (traceCount & 0x3FF) != 0)
+        {
+            return;
+        }
+
+        var returnRip = 0UL;
+        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rsp], out returnRip);
+        Console.Error.WriteLine(
+            $"[LOADER][TRACE] apr.{operation}: id=0x{submissionId:X8} cmd=0x{commandBuffer:X16} " +
+            $"rsi=0x{priority:X16} rdx=0x{resultAddress:X16} rcx=0x{ctx[CpuRegister.Rcx]:X16} " +
+            $"r8=0x{ctx[CpuRegister.R8]:X16} r9=0x{ctx[CpuRegister.R9]:X16} ret=0x{returnRip:X16}");
+        TraceReadableQword(ctx, operation, "rsi", priority);
+        TraceReadableQword(ctx, operation, "rdx", resultAddress);
+        TraceReadableQword(ctx, operation, "rcx", ctx[CpuRegister.Rcx]);
+        TraceReadableQword(ctx, operation, "r8", ctx[CpuRegister.R8]);
+    }
+
+    private static void TraceReadableQword(CpuContext ctx, string operation, string name, ulong address)
+    {
+        if (address == 0 || !ctx.TryReadUInt64(address, out var value))
+        {
+            return;
+        }
+
+        Console.Error.WriteLine(
+            $"[LOADER][TRACE] apr.{operation}.{name}: addr=0x{address:X16} q0=0x{value:X16}");
+    }
 }

src/SharpEmu.Libs/Kernel/KernelEventFlagCompatExports.cs

@@ -127,6 +127,7 @@ public static class KernelEventFlagCompatExports
             TraceEventFlag($"set handle=0x{handle:X16} pattern=0x{pattern:X16} bits=0x{state.Bits:X16} ret=0x{returnRip:X16}");
         }
 
+        _ = GuestThreadExecution.Scheduler?.WakeBlockedThreads(GetEventFlagWakeKey(handle));
         return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_OK);
     }
 
@@ -226,7 +227,7 @@ public static class KernelEventFlagCompatExports
         Monitor.Enter(state.Gate);
         try
         {
-            if (TryCompleteSatisfiedWait(ctx, state, pattern, waitMode, out var immediateWaitResult))
+            if (TryCompleteSatisfiedWait(ctx, state, pattern, waitMode, resultAddress, out var immediateWaitResult))
             {
                 return SetReturn(ctx, immediateWaitResult);
             }
@@ -242,7 +243,28 @@ public static class KernelEventFlagCompatExports
             var currentGuestThread = GuestThreadExecution.CurrentGuestThreadHandle;
             var currentFiber = FiberExports.GetCurrentFiberAddressForDiagnostics(ctx);
             var managedThread = Environment.CurrentManagedThreadId;
-            var requestedBlock = GuestThreadExecution.RequestCurrentThreadBlock("sceKernelWaitEventFlag");
+            var blockedWaitResult = OrbisGen2Result.ORBIS_GEN2_OK;
+            var requestedBlock = GuestThreadExecution.RequestCurrentThreadBlock(
+                ctx,
+                "sceKernelWaitEventFlag",
+                GetEventFlagWakeKey(handle),
+                () => (int)blockedWaitResult,
+                () =>
+                {
+                    if (!TryPrepareBlockedWait(
+                            ctx,
+                            state,
+                            pattern,
+                            waitMode,
+                            resultAddress,
+                            out var preparedResult))
+                    {
+                        return false;
+                    }
+
+                    blockedWaitResult = preparedResult;
+                    return true;
+                });
             TraceEventFlag($"wait-unsatisfied handle=0x{handle:X16} pattern=0x{pattern:X16} bits=0x{state.Bits:X16} guest_thread=0x{currentGuestThread:X16} fiber=0x{currentFiber:X16} managed={managedThread} block={requestedBlock} ret=0x{returnRip:X16} frames={FormatFrameChain(ctx)}");
             TraceEventFlag($"wait-object handle=0x{handle:X16} name='{state.Name}' {FormatGuestWaitObject(ctx)}");
             if (!requestedBlock)
@@ -270,7 +292,7 @@ public static class KernelEventFlagCompatExports
                             Monitor.Enter(state.Gate);
                         }
 
-                        if (TryCompleteSatisfiedWait(ctx, state, pattern, waitMode, out var pumpedWaitResult))
+                        if (TryCompleteSatisfiedWait(ctx, state, pattern, waitMode, resultAddress, out var pumpedWaitResult))
                         {
                             state.WaitingThreads = Math.Max(0, state.WaitingThreads - 1);
                             releaseWaiter = false;
@@ -369,19 +391,21 @@ public static class KernelEventFlagCompatExports
     }
 
     private static bool TryCompleteSatisfiedWait(
-        CpuContext ctx,
+    CpuContext ctx,
-        EventFlagState state,
+    EventFlagState state,
-        ulong pattern,
+    ulong pattern,
-        uint waitMode,
+    uint waitMode,
-        out OrbisGen2Result result)
+    ulong resultAddress,
+    out OrbisGen2Result result)
     {
         result = OrbisGen2Result.ORBIS_GEN2_OK;
+
         if (!IsSatisfied(state.Bits, pattern, waitMode))
         {
             return false;
         }
 
-        if (!TryWriteResultPattern(ctx, ctx[CpuRegister.Rcx], state.Bits))
+        if (!TryWriteResultPattern(ctx, resultAddress, state.Bits))
         {
             result = OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
             return true;
@@ -391,6 +415,41 @@ public static class KernelEventFlagCompatExports
         return true;
     }
 
+    private static bool TryPrepareBlockedWait(
+        CpuContext ctx,
+        EventFlagState state,
+        ulong pattern,
+        uint waitMode,
+        ulong resultAddress,
+        out OrbisGen2Result result)
+    {
+        lock (state.Gate)
+        {
+            result = OrbisGen2Result.ORBIS_GEN2_OK;
+            if (!IsSatisfied(state.Bits, pattern, waitMode))
+            {
+                return false;
+            }
+
+            if (!TryWriteResultPattern(ctx, resultAddress, state.Bits))
+            {
+                result = OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+            }
+            else
+            {
+                ApplyClearMode(state, pattern, waitMode);
+            }
+
+            state.WaitingThreads = Math.Max(0, state.WaitingThreads - 1);
+            TraceEventFlag(
+                $"wait-wake pattern=0x{pattern:X16} mode=0x{waitMode:X2} bits=0x{state.Bits:X16} waiters={state.WaitingThreads}");
+            return true;
+        }
+    }
+
+    private static string GetEventFlagWakeKey(ulong handle) =>
+        $"event_flag:0x{handle:X16}";
+
     private static bool TryWriteResultPattern(CpuContext ctx, ulong address, ulong bits) =>
         address == 0 || ctx.TryWriteUInt64(address, bits);
 

src/SharpEmu.Libs/Kernel/KernelEventQueueCompatExports.cs

@@ -10,10 +10,14 @@ namespace SharpEmu.Libs.Kernel;
 public static class KernelEventQueueCompatExports
 {
     private const int KernelEventSize = 0x20;
+    public const short KernelEventFilterGraphics = -14;
+    public const short KernelEventFilterAmpr = -16;
+    public const short KernelEventFilterAmprSystem = -17;
 
     private static readonly object _eventQueueGate = new();
     private static readonly HashSet<ulong> _eventQueues = new();
     private static readonly Dictionary<ulong, LinkedList<KernelQueuedEvent>> _pendingEvents = new();
+    private static readonly Dictionary<ulong, Dictionary<(ulong Ident, short Filter), KernelEventRegistration>> _registeredEvents = new();
     private static long _nextEventQueueHandle = 1;
 
     public readonly record struct KernelQueuedEvent(
@@ -24,6 +28,11 @@ public static class KernelEventQueueCompatExports
         ulong Data,
         ulong UserData);
 
+    private readonly record struct KernelEventRegistration(
+        ulong Ident,
+        short Filter,
+        ulong UserData);
+
     [SysAbiExport(
         Nid = "D0OdFMjp46I",
         ExportName = "sceKernelCreateEqueue",
@@ -42,6 +51,7 @@ public static class KernelEventQueueCompatExports
         {
             _eventQueues.Add(handle);
             _pendingEvents[handle] = new LinkedList<KernelQueuedEvent>();
+            _registeredEvents[handle] = new Dictionary<(ulong Ident, short Filter), KernelEventRegistration>();
         }
 
         if (!ctx.TryWriteUInt64(outAddress, handle))
@@ -65,6 +75,7 @@ public static class KernelEventQueueCompatExports
         {
             _eventQueues.Remove(handle);
             _pendingEvents.Remove(handle);
+            _registeredEvents.Remove(handle);
         }
 
         TraceEventQueue(ctx, "delete", handle);
@@ -122,8 +133,16 @@ public static class KernelEventQueueCompatExports
         LibraryName = "libKernel")]
     public static int KernelAddAmprEvent(CpuContext ctx)
     {
-        TraceEventQueue(ctx, "add_ampr", ctx[CpuRegister.Rdi]);
+        var handle = ctx[CpuRegister.Rdi];
-        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        var registered = RegisterEvent(
+            handle,
+            unchecked((uint)ctx[CpuRegister.Rsi]),
+            KernelEventFilterAmpr,
+            ctx[CpuRegister.Rdx]);
+        TraceEventQueue(ctx, "add_ampr", handle);
+        return registered
+            ? (int)OrbisGen2Result.ORBIS_GEN2_OK
+            : (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
     }
 
     [SysAbiExport(
@@ -133,8 +152,16 @@ public static class KernelEventQueueCompatExports
         LibraryName = "libKernel")]
     public static int KernelAddAmprSystemEvent(CpuContext ctx)
     {
-        TraceEventQueue(ctx, "add_ampr_system", ctx[CpuRegister.Rdi]);
+        var handle = ctx[CpuRegister.Rdi];
-        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        var registered = RegisterEvent(
+            handle,
+            unchecked((uint)ctx[CpuRegister.Rsi]),
+            KernelEventFilterAmprSystem,
+            ctx[CpuRegister.Rdx]);
+        TraceEventQueue(ctx, "add_ampr_system", handle);
+        return registered
+            ? (int)OrbisGen2Result.ORBIS_GEN2_OK
+            : (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
     }
 
     [SysAbiExport(
@@ -144,8 +171,15 @@ public static class KernelEventQueueCompatExports
         LibraryName = "libKernel")]
     public static int KernelDeleteAmprEvent(CpuContext ctx)
     {
-        TraceEventQueue(ctx, "delete_ampr", ctx[CpuRegister.Rdi]);
+        var handle = ctx[CpuRegister.Rdi];
-        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        var deleted = DeleteRegisteredEvent(
+            handle,
+            unchecked((uint)ctx[CpuRegister.Rsi]),
+            KernelEventFilterAmpr);
+        TraceEventQueue(ctx, "delete_ampr", handle);
+        return deleted
+            ? (int)OrbisGen2Result.ORBIS_GEN2_OK
+            : (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
     }
 
     [SysAbiExport(
@@ -155,8 +189,15 @@ public static class KernelEventQueueCompatExports
         LibraryName = "libKernel")]
     public static int KernelDeleteAmprSystemEvent(CpuContext ctx)
     {
-        TraceEventQueue(ctx, "delete_ampr_system", ctx[CpuRegister.Rdi]);
+        var handle = ctx[CpuRegister.Rdi];
-        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        var deleted = DeleteRegisteredEvent(
+            handle,
+            unchecked((uint)ctx[CpuRegister.Rsi]),
+            KernelEventFilterAmprSystem);
+        TraceEventQueue(ctx, "delete_ampr_system", handle);
+        return deleted
+            ? (int)OrbisGen2Result.ORBIS_GEN2_OK
+            : (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
     }
 
     [SysAbiExport(
@@ -171,6 +212,57 @@ public static class KernelEventQueueCompatExports
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
+    [SysAbiExport(
+        Nid = "vz+pg2zdopI",
+        ExportName = "sceKernelGetEventUserData",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelGetEventUserData(CpuContext ctx)
+    {
+        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rdi] + 0x18, out var userData);
+        ctx[CpuRegister.Rax] = userData;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "mJ7aghmgvfc",
+        ExportName = "sceKernelGetEventId",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelGetEventId(CpuContext ctx)
+    {
+        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rdi], out var ident);
+        ctx[CpuRegister.Rax] = ident;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "23CPPI1tyBY",
+        ExportName = "sceKernelGetEventFilter",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelGetEventFilter(CpuContext ctx)
+    {
+        Span<byte> filterBytes = stackalloc byte[sizeof(short)];
+        var filter = ctx.Memory.TryRead(ctx[CpuRegister.Rdi] + 0x08, filterBytes)
+            ? BinaryPrimitives.ReadInt16LittleEndian(filterBytes)
+            : (short)0;
+        ctx[CpuRegister.Rax] = unchecked((uint)filter);
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "kwGyyjohI50",
+        ExportName = "sceKernelGetEventData",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelGetEventData(CpuContext ctx)
+    {
+        _ = ctx.TryReadUInt64(ctx[CpuRegister.Rdi] + 0x10, out var data);
+        ctx[CpuRegister.Rax] = data;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
     [SysAbiExport(
         Nid = "fzyMKs9kim0",
         ExportName = "sceKernelWaitEqueue",
@@ -196,7 +288,13 @@ public static class KernelEventQueueCompatExports
             return (int)OrbisGen2Result.ORBIS_GEN2_OK;
         }
 
-        if (timeoutAddress == 0 && GuestThreadExecution.RequestCurrentThreadBlock("sceKernelWaitEqueue"))
+        if (timeoutAddress == 0 &&
+            GuestThreadExecution.RequestCurrentThreadBlock(
+                ctx,
+                "sceKernelWaitEqueue",
+                GetEventQueueWakeKey(handle),
+                () => ResumeWaitEqueue(ctx, handle, eventsAddress, eventCapacity, outCountAddress),
+                () => HasPendingEvents(handle)))
         {
             TraceEventQueue(ctx, "wait-block", handle);
             return (int)OrbisGen2Result.ORBIS_GEN2_OK;
@@ -216,6 +314,7 @@ public static class KernelEventQueueCompatExports
 
     public static bool EnqueueEvent(ulong handle, KernelQueuedEvent queuedEvent)
     {
+        var queued = false;
         lock (_eventQueueGate)
         {
             if (!_eventQueues.Contains(handle))
@@ -230,10 +329,100 @@ public static class KernelEventQueueCompatExports
             }
 
             queue.AddLast(queuedEvent);
+            queued = true;
+        }
+
+        if (queued)
+        {
+            WakeEventQueue(handle);
+        }
+
+        return queued;
+    }
+
+    public static bool RegisterEvent(
+        ulong handle,
+        ulong ident,
+        short filter,
+        ulong userData)
+    {
+        lock (_eventQueueGate)
+        {
+            if (!_eventQueues.Contains(handle))
+            {
+                return false;
+            }
+
+            if (!_registeredEvents.TryGetValue(handle, out var events))
+            {
+                events = new Dictionary<(ulong Ident, short Filter), KernelEventRegistration>();
+                _registeredEvents[handle] = events;
+            }
+
+            events[(ident, filter)] = new KernelEventRegistration(ident, filter, userData);
             return true;
         }
     }
 
+    public static bool DeleteRegisteredEvent(
+        ulong handle,
+        ulong ident,
+        short filter)
+    {
+        lock (_eventQueueGate)
+        {
+            return _registeredEvents.TryGetValue(handle, out var events) &&
+                   events.Remove((ident, filter));
+        }
+    }
+
+    public static int TriggerRegisteredEvents(
+        ulong ident,
+        short filter,
+        ulong data)
+    {
+        List<ulong>? wakeHandles = null;
+        var triggeredCount = 0;
+        lock (_eventQueueGate)
+        {
+            foreach (var (handle, registrations) in _registeredEvents)
+            {
+                if (!registrations.TryGetValue((ident, filter), out var registration))
+                {
+                    continue;
+                }
+
+                if (!_pendingEvents.TryGetValue(handle, out var queue))
+                {
+                    queue = new LinkedList<KernelQueuedEvent>();
+                    _pendingEvents[handle] = queue;
+                }
+
+                QueueOrUpdateEvent(
+                    queue,
+                    new KernelQueuedEvent(
+                        registration.Ident,
+                        registration.Filter,
+                        0,
+                        1,
+                        data,
+                        registration.UserData));
+                (wakeHandles ??= new List<ulong>()).Add(handle);
+                triggeredCount++;
+            }
+        }
+
+        if (wakeHandles is not null)
+        {
+            foreach (var handle in wakeHandles)
+            {
+                WakeEventQueue(handle);
+            }
+        }
+
+        return triggeredCount;
+    }
+
     public static bool TriggerDisplayEvent(
         ulong handle,
         ulong ident,
@@ -241,6 +430,7 @@ public static class KernelEventQueueCompatExports
         ulong eventHint,
         ulong userData)
     {
+        var triggered = false;
         lock (_eventQueueGate)
         {
             if (!_eventQueues.Contains(handle))
@@ -254,17 +444,8 @@ public static class KernelEventQueueCompatExports
                 _pendingEvents[handle] = events;
             }
 
-            LinkedListNode<KernelQueuedEvent>? pendingNode = null;
-            for (var node = events.First; node is not null; node = node.Next)
-            {
-                if (node.Value.Ident == ident && node.Value.Filter == filter)
-                {
-                    pendingNode = node;
-                    break;
-                }
-            }
-
             var count = 1UL;
+            var pendingNode = FindPendingEvent(events, ident, filter);
             if (pendingNode is not null)
             {
                 count = Math.Min(((pendingNode.Value.Data >> 12) & 0xFUL) + 1, 0xFUL);
@@ -289,8 +470,80 @@ public static class KernelEventQueueCompatExports
                 events.AddLast(triggeredEvent);
             }
 
-            return true;
+            triggered = true;
         }
+
+        if (triggered)
+        {
+            WakeEventQueue(handle);
+        }
+
+        return triggered;
+    }
+
+    private static int ResumeWaitEqueue(
+        CpuContext ctx,
+        ulong handle,
+        ulong eventsAddress,
+        int eventCapacity,
+        ulong outCountAddress)
+    {
+        var deliveredCount = DequeueEvents(ctx, handle, eventsAddress, eventCapacity);
+        if (outCountAddress != 0 && !TryWriteUInt32(ctx, outCountAddress, (uint)deliveredCount))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    private static bool HasPendingEvents(ulong handle)
+    {
+        lock (_eventQueueGate)
+        {
+            return _pendingEvents.TryGetValue(handle, out var events) && events.Count != 0;
+        }
+    }
+
+    private static void QueueOrUpdateEvent(
+        LinkedList<KernelQueuedEvent> queue,
+        KernelQueuedEvent queuedEvent)
+    {
+        var pendingNode = FindPendingEvent(queue, queuedEvent.Ident, queuedEvent.Filter);
+        if (pendingNode is null)
+        {
+            queue.AddLast(queuedEvent);
+            return;
+        }
+
+        pendingNode.Value = queuedEvent with
+        {
+            Fflags = Math.Max(pendingNode.Value.Fflags + 1, queuedEvent.Fflags),
+        };
+    }
+
+    private static LinkedListNode<KernelQueuedEvent>? FindPendingEvent(
+        LinkedList<KernelQueuedEvent> queue,
+        ulong ident,
+        short filter)
+    {
+        for (var node = queue.First; node is not null; node = node.Next)
+        {
+            if (node.Value.Ident == ident && node.Value.Filter == filter)
+            {
+                return node;
+            }
+        }
+
+        return null;
+    }
+
+    private static string GetEventQueueWakeKey(ulong handle) =>
+        $"sceKernelWaitEqueue:{handle:X16}";
+
+    private static void WakeEventQueue(ulong handle)
+    {
+        _ = GuestThreadExecution.Scheduler?.WakeBlockedThreads(GetEventQueueWakeKey(handle));
     }
 
     private static int DequeueEvents(CpuContext ctx, ulong handle, ulong eventsAddress, int eventCapacity)

src/SharpEmu.Libs/Kernel/KernelExports.cs

@@ -252,6 +252,32 @@ public static class KernelExports
         return PthreadCreate(ctx);
     }
 
+    [SysAbiExport(
+        Nid = "3kg7rT0NQIs",
+        ExportName = "scePthreadExit",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int PthreadExit(CpuContext ctx)
+    {
+        var value = ctx[CpuRegister.Rdi];
+        GuestThreadExecution.RequestCurrentEntryExit("scePthreadExit", value);
+        ctx[CpuRegister.Rax] = value;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
+    [SysAbiExport(
+        Nid = "FJrT5LuUBAU",
+        ExportName = "pthread_exit",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libScePosix")]
+    public static int PosixPthreadExit(CpuContext ctx)
+    {
+        var value = ctx[CpuRegister.Rdi];
+        GuestThreadExecution.RequestCurrentEntryExit("pthread_exit", value);
+        ctx[CpuRegister.Rax] = value;
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
     [SysAbiExport(
         Nid = "onNY9Byn-W8",
         ExportName = "scePthreadJoin",

src/SharpEmu.Libs/Kernel/KernelMemoryCompatExports.cs

@@ -65,6 +65,7 @@ public static class KernelMemoryCompatExports
     private const uint HostPageExecuteWriteCopy = 0x80;
     private const uint HostPageGuard = 0x100;
     private const int Enomem = 12;
+    private const int Efault = 14;
     private const int Einval = 22;
     private const int Erange = 34;
     private const int Struncate = 80;
@@ -96,10 +97,14 @@ public static class KernelMemoryCompatExports
     private static readonly object _libcAllocGate = new();
     private static readonly object _memoryGate = new();
     private static readonly object _tlsGate = new();
+    private static readonly object _ioTraceGate = new();
+    private static readonly object _statCacheGate = new();
     private static readonly Dictionary<ulong, DirectAllocation> _directAllocations = new();
     private static readonly Dictionary<ulong, LibcHeapAllocation> _libcAllocations = new();
     private static readonly Dictionary<ulong, MappedRegion> _mappedRegions = new();
     private static readonly Dictionary<ulong, ulong> _tlsModuleBlocks = new();
+    private static readonly HashSet<string> _tracedStatResults = new(StringComparer.Ordinal);
+    private static readonly HashSet<string> _negativeStatCache = new(StringComparer.OrdinalIgnoreCase);
     private static long _nextFileDescriptor = 2;
     private static ulong _nextPhysicalAddress;
     private static ulong _nextVirtualAddress;
@@ -114,6 +119,8 @@ public static class KernelMemoryCompatExports
     private static int _hostMemoryWriteFallbackCount;
     private static int _hostMemoryReadFallbackCount;
     private static int _nullWcscpyRecoveryCount;
+    private static string? _cachedApp0Root;
+    private static string? _cachedDownload0Root;
 
     [StructLayout(LayoutKind.Sequential)]
     private struct MemoryBasicInformation
@@ -1236,6 +1243,12 @@ public static class KernelMemoryCompatExports
         var mode = ResolveOpenMode(flags, access);
         try
         {
+            if (IsMutatingOpen(flags) && IsReadOnlyGuestMutationPath(guestPath))
+            {
+                LogOpenTrace($"_open readonly path='{guestPath}' host='{hostPath}' flags=0x{flags:X8}");
+                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_PERMISSION_DENIED;
+            }
+
             var wantsDirectory = (flags & O_DIRECTORY) != 0;
             if (wantsDirectory || Directory.Exists(hostPath))
             {
@@ -1280,6 +1293,11 @@ public static class KernelMemoryCompatExports
                 _openFiles[fd] = stream;
             }
 
+            if (IsMutatingOpen(flags))
+            {
+                InvalidateNegativeStatCacheForPathAndAncestors(guestPath);
+            }
+
             LogOpenTrace($"_open file path='{guestPath}' host='{hostPath}' flags=0x{flags:X8} fd={fd}");
             ctx[CpuRegister.Rax] = unchecked((ulong)fd);
             return (int)OrbisGen2Result.ORBIS_GEN2_OK;
@@ -1334,11 +1352,30 @@ public static class KernelMemoryCompatExports
         }
 
         var hostPath = ResolveGuestPath(guestPath);
-        if (!TryWriteHostPathStat(ctx, statAddress, hostPath))
+        var statCacheKey = GetNegativeStatCacheKey(guestPath);
+        if (statCacheKey is not null && IsNegativeStatCached(statCacheKey))
         {
+            LogUniqueStatTrace(guestPath, hostPath, found: false);
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
         }
 
+        if (!TryWriteHostPathStat(ctx, statAddress, hostPath))
+        {
+            if (statCacheKey is not null)
+            {
+                AddNegativeStatCache(statCacheKey);
+            }
+
+            LogUniqueStatTrace(guestPath, hostPath, found: false);
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+        }
+
+        if (statCacheKey is not null)
+        {
+            RemoveNegativeStatCache(statCacheKey);
+        }
+
+        LogUniqueStatTrace(guestPath, hostPath, found: true);
         ctx[CpuRegister.Rax] = 0;
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
@@ -1356,13 +1393,22 @@ public static class KernelMemoryCompatExports
         var sizesAddress = ctx[CpuRegister.Rcx];
         if (pathListAddress == 0 || count == 0 || sizesAddress == 0 || count > 1024)
         {
+            KernelRuntimeCompatExports.TrySetErrno(ctx, Einval);
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
         }
 
         for (ulong i = 0; i < count; i++)
         {
+            if (idsAddress != 0 &&
+                !TryWriteUInt32Compat(ctx, idsAddress + (i * sizeof(uint)), uint.MaxValue))
+            {
+                KernelRuntimeCompatExports.TrySetErrno(ctx, Efault);
+                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+            }
+
             if (!TryResolveAprFilepath(ctx, pathListAddress, i, out var guestPath))
             {
+                KernelRuntimeCompatExports.TrySetErrno(ctx, Efault);
                 return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
             }
 
@@ -1370,6 +1416,7 @@ public static class KernelMemoryCompatExports
             if (!TryGetAprFileSize(hostPath, out var fileSize))
             {
                 LogIoTrace("apr_resolve", guestPath, $"host='{hostPath}' index={i} count={count} result=not_found");
+                KernelRuntimeCompatExports.TrySetErrno(ctx, 2);
                 return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
             }
 
@@ -1379,11 +1426,13 @@ public static class KernelMemoryCompatExports
             if (idsAddress != 0 &&
                 !TryWriteUInt32Compat(ctx, idsAddress + (i * sizeof(uint)), fileId))
             {
+                KernelRuntimeCompatExports.TrySetErrno(ctx, Efault);
                 return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
             }
 
             if (!TryWriteUInt64Compat(ctx, sizesAddress + (i * sizeof(ulong)), fileSize))
             {
+                KernelRuntimeCompatExports.TrySetErrno(ctx, Efault);
                 return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
             }
         }
@@ -1415,6 +1464,170 @@ public static class KernelMemoryCompatExports
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
+    [SysAbiExport(
+        Nid = "AUXVxWeJU-A",
+        ExportName = "sceKernelUnlink",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelUnlink(CpuContext ctx)
+    {
+        var pathAddress = ctx[CpuRegister.Rdi];
+        if (pathAddress == 0)
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+
+        if (!TryReadNullTerminatedUtf8(ctx, pathAddress, MaxGuestStringLength, out var guestPath))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
+        var hostPath = ResolveGuestPath(guestPath);
+        if (IsReadOnlyGuestMutationPath(guestPath))
+        {
+            LogOpenTrace($"unlink readonly path='{guestPath}' host='{hostPath}'");
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_PERMISSION_DENIED;
+        }
+
+        try
+        {
+            if (Directory.Exists(hostPath))
+            {
+                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_PERMISSION_DENIED;
+            }
+
+            if (!File.Exists(hostPath))
+            {
+                AddNegativeStatCacheForGuestPath(guestPath);
+                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+            }
+
+            File.Delete(hostPath);
+            InvalidateNegativeStatCacheForPathAndAncestors(guestPath);
+            AddNegativeStatCacheForGuestPath(guestPath);
+            LogOpenTrace($"unlink path='{guestPath}' host='{hostPath}'");
+            ctx[CpuRegister.Rax] = 0;
+            return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        }
+        catch (UnauthorizedAccessException)
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_PERMISSION_DENIED;
+        }
+        catch (IOException)
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_BUSY;
+        }
+    }
+
+    [SysAbiExport(
+        Nid = "1-LFLmRFxxM",
+        ExportName = "sceKernelMkdir",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelMkdir(CpuContext ctx)
+    {
+        var pathAddress = ctx[CpuRegister.Rdi];
+        if (pathAddress == 0)
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+
+        if (!TryReadNullTerminatedUtf8(ctx, pathAddress, MaxGuestStringLength, out var guestPath))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
+        var hostPath = ResolveGuestPath(guestPath);
+        if (IsReadOnlyGuestMutationPath(guestPath))
+        {
+            LogOpenTrace($"mkdir readonly path='{guestPath}' host='{hostPath}'");
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_PERMISSION_DENIED;
+        }
+
+        try
+        {
+            if (File.Exists(hostPath) || Directory.Exists(hostPath))
+            {
+                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_ALREADY_EXISTS;
+            }
+
+            var parentDirectory = Path.GetDirectoryName(hostPath);
+            if (string.IsNullOrWhiteSpace(parentDirectory) || !Directory.Exists(parentDirectory))
+            {
+                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+            }
+
+            Directory.CreateDirectory(hostPath);
+            if (!Directory.Exists(hostPath))
+            {
+                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+            }
+
+            InvalidateNegativeStatCacheForPathAndAncestors(guestPath);
+            LogOpenTrace($"mkdir path='{guestPath}' host='{hostPath}'");
+            ctx[CpuRegister.Rax] = 0;
+            return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        }
+        catch (UnauthorizedAccessException)
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_PERMISSION_DENIED;
+        }
+        catch (IOException)
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+    }
+
+    [SysAbiExport(
+        Nid = "naInUjYt3so",
+        ExportName = "sceKernelRmdir",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libKernel")]
+    public static int KernelRmdir(CpuContext ctx)
+    {
+        var pathAddress = ctx[CpuRegister.Rdi];
+        if (pathAddress == 0)
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT;
+        }
+
+        if (!TryReadNullTerminatedUtf8(ctx, pathAddress, MaxGuestStringLength, out var guestPath))
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
+        }
+
+        var hostPath = ResolveGuestPath(guestPath);
+        if (IsReadOnlyGuestMutationPath(guestPath))
+        {
+            LogOpenTrace($"rmdir readonly path='{guestPath}' host='{hostPath}'");
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_PERMISSION_DENIED;
+        }
+
+        try
+        {
+            if (!Directory.Exists(hostPath))
+            {
+                AddNegativeStatCacheForGuestPath(guestPath);
+                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
+            }
+
+            Directory.Delete(hostPath, recursive: false);
+            InvalidateNegativeStatCacheForPathAndAncestors(guestPath);
+            AddNegativeStatCacheForGuestPath(guestPath);
+            LogOpenTrace($"rmdir path='{guestPath}' host='{hostPath}'");
+            ctx[CpuRegister.Rax] = 0;
+            return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        }
+        catch (UnauthorizedAccessException)
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_PERMISSION_DENIED;
+        }
+        catch (IOException)
+        {
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_BUSY;
+        }
+    }
+
     private static int KernelCloseCore(CpuContext ctx, int fd)
     {
         if (fd is 0 or 1 or 2)
@@ -3798,57 +4011,72 @@ public static class KernelMemoryCompatExports
             return guestPath;
         }
 
-        var devlogAppRoot = ResolveDevlogAppRoot();
         if (guestPath.StartsWith("/devlog/app/", StringComparison.OrdinalIgnoreCase))
         {
             var relative = NormalizeMountRelativePath(guestPath["/devlog/app/".Length..]);
-            return Path.Combine(devlogAppRoot, relative);
+            return Path.Combine(ResolveDevlogAppRoot(), relative);
         }
 
         if (guestPath.StartsWith("devlog/app/", StringComparison.OrdinalIgnoreCase))
         {
             var relative = NormalizeMountRelativePath(guestPath["devlog/app/".Length..]);
-            return Path.Combine(devlogAppRoot, relative);
+            return Path.Combine(ResolveDevlogAppRoot(), relative);
         }
 
         if (string.Equals(guestPath, "/devlog/app", StringComparison.OrdinalIgnoreCase) ||
             string.Equals(guestPath, "devlog/app", StringComparison.OrdinalIgnoreCase))
         {
-            return devlogAppRoot;
+            return ResolveDevlogAppRoot();
         }
 
-        var temp0Root = ResolveTemp0Root();
         if (guestPath.StartsWith("/temp0/", StringComparison.OrdinalIgnoreCase))
         {
             var relative = NormalizeMountRelativePath(guestPath["/temp0/".Length..]);
-            return Path.Combine(temp0Root, relative);
+            return Path.Combine(ResolveTemp0Root(), relative);
         }
 
         if (string.Equals(guestPath, "/temp0", StringComparison.OrdinalIgnoreCase))
         {
-            return temp0Root;
+            return ResolveTemp0Root();
+        }
+
+        if (guestPath.StartsWith("/download0/", StringComparison.OrdinalIgnoreCase))
+        {
+            var relative = NormalizeMountRelativePath(guestPath["/download0/".Length..]);
+            return Path.Combine(ResolveDownload0Root(), relative);
+        }
+
+        if (guestPath.StartsWith("download0/", StringComparison.OrdinalIgnoreCase))
+        {
+            var relative = NormalizeMountRelativePath(guestPath["download0/".Length..]);
+            return Path.Combine(ResolveDownload0Root(), relative);
+        }
+
+        if (string.Equals(guestPath, "/download0", StringComparison.OrdinalIgnoreCase) ||
+            string.Equals(guestPath, "download0", StringComparison.OrdinalIgnoreCase))
+        {
+            return ResolveDownload0Root();
         }
 
-        var hostappRoot = ResolveHostappRoot();
         if (guestPath.StartsWith("/hostapp/", StringComparison.OrdinalIgnoreCase))
         {
             var relative = NormalizeMountRelativePath(guestPath["/hostapp/".Length..]);
-            return Path.Combine(hostappRoot, relative);
+            return Path.Combine(ResolveHostappRoot(), relative);
         }
 
         if (guestPath.StartsWith("hostapp/", StringComparison.OrdinalIgnoreCase))
         {
             var relative = NormalizeMountRelativePath(guestPath["hostapp/".Length..]);
-            return Path.Combine(hostappRoot, relative);
+            return Path.Combine(ResolveHostappRoot(), relative);
         }
 
         if (string.Equals(guestPath, "/hostapp", StringComparison.OrdinalIgnoreCase) ||
             string.Equals(guestPath, "hostapp", StringComparison.OrdinalIgnoreCase))
         {
-            return hostappRoot;
+            return ResolveHostappRoot();
         }
 
-        var app0Root = Environment.GetEnvironmentVariable("SHARPEMU_APP0_DIR");
+        var app0Root = ResolveApp0Root();
         if (!string.IsNullOrWhiteSpace(app0Root))
         {
             if (string.Equals(guestPath, "/app0", StringComparison.OrdinalIgnoreCase) ||
@@ -3881,6 +4109,24 @@ public static class KernelMemoryCompatExports
         return guestPath;
     }
 
+    private static string? ResolveApp0Root()
+    {
+        var cached = Volatile.Read(ref _cachedApp0Root);
+        if (!string.IsNullOrWhiteSpace(cached))
+        {
+            return cached;
+        }
+
+        var configured = Environment.GetEnvironmentVariable("SHARPEMU_APP0_DIR");
+        if (string.IsNullOrWhiteSpace(configured))
+        {
+            return null;
+        }
+
+        Interlocked.CompareExchange(ref _cachedApp0Root, configured, null);
+        return _cachedApp0Root;
+    }
+
     private static string NormalizeMountRelativePath(string relativePath)
     {
         return relativePath
@@ -3931,6 +4177,32 @@ public static class KernelMemoryCompatExports
         return root;
     }
 
+    private static string ResolveDownload0Root()
+    {
+        var cached = Volatile.Read(ref _cachedDownload0Root);
+        if (!string.IsNullOrWhiteSpace(cached))
+        {
+            return cached;
+        }
+
+        const string download0VariableName = "SHARPEMU_DOWNLOAD0_DIR";
+        var configuredRoot = Environment.GetEnvironmentVariable(download0VariableName);
+        string root;
+        if (!string.IsNullOrWhiteSpace(configuredRoot))
+        {
+            root = Path.GetFullPath(configuredRoot);
+        }
+        else
+        {
+            root = Path.Combine(GetPerAppWritableRoot(), "download0");
+            Environment.SetEnvironmentVariable(download0VariableName, root);
+        }
+
+        Directory.CreateDirectory(root);
+        Interlocked.CompareExchange(ref _cachedDownload0Root, root, null);
+        return _cachedDownload0Root;
+    }
+
     private static string ResolveHostappRoot()
     {
         const string hostappVariableName = "SHARPEMU_HOSTAPP_DIR";
@@ -3950,6 +4222,22 @@ public static class KernelMemoryCompatExports
         return root;
     }
 
+    private static string GetPerAppWritableRoot()
+    {
+        var app0Root = Environment.GetEnvironmentVariable("SHARPEMU_APP0_DIR");
+        var appName = string.IsNullOrWhiteSpace(app0Root)
+            ? "default"
+            : Path.GetFileName(Path.TrimEndingDirectorySeparator(app0Root));
+        if (string.IsNullOrWhiteSpace(appName))
+        {
+            appName = "default";
+        }
+
+        var invalidChars = Path.GetInvalidFileNameChars();
+        appName = new string(appName.Select(ch => invalidChars.Contains(ch) ? '_' : ch).ToArray());
+        return Path.Combine(Path.GetTempPath(), "SharpEmu", appName);
+    }
+
     private static void EnsureOpenParentDirectoryExists(string guestPath, string hostPath, int flags)
     {
         if (string.IsNullOrWhiteSpace(hostPath))
@@ -3973,6 +4261,17 @@ public static class KernelMemoryCompatExports
         }
     }
 
+    private static bool IsMutatingOpen(int flags) =>
+        (flags & (O_WRONLY | O_RDWR | O_CREAT | O_TRUNC | O_APPEND)) != 0;
+
+    private static bool IsReadOnlyGuestMutationPath(string guestPath)
+    {
+        var normalized = NormalizeGuestStatCachePath(guestPath);
+        return normalized is not null &&
+               (string.Equals(normalized, "/app0", StringComparison.OrdinalIgnoreCase) ||
+                normalized.StartsWith("/app0/", StringComparison.OrdinalIgnoreCase));
+    }
+
     private static bool TryReadCString(CpuContext ctx, ulong address, ulong maxLength, out byte[] bytes)
     {
         return TryReadBytesUntilNull(ctx, address, maxLength, 1_048_576, out bytes);
@@ -4350,7 +4649,7 @@ public static class KernelMemoryCompatExports
         return true;
     }
 
-    private static bool TryReadUInt64Compat(CpuContext ctx, ulong address, out ulong value)
+    internal static bool TryReadUInt64Compat(CpuContext ctx, ulong address, out ulong value)
     {
         Span<byte> bytes = stackalloc byte[sizeof(ulong)];
         if (!TryReadCompat(ctx, address, bytes))
@@ -4397,7 +4696,7 @@ public static class KernelMemoryCompatExports
         return TryWriteCompat(ctx, address, bytes);
     }
 
-    private static bool TryWriteUInt64Compat(CpuContext ctx, ulong address, ulong value)
+    internal static bool TryWriteUInt64Compat(CpuContext ctx, ulong address, ulong value)
     {
         Span<byte> bytes = stackalloc byte[sizeof(ulong)];
         BinaryPrimitives.WriteUInt64LittleEndian(bytes, value);
@@ -5345,19 +5644,20 @@ public static class KernelMemoryCompatExports
         size = 0;
         try
         {
-            if (Directory.Exists(hostPath))
+            var fileInfo = new FileInfo(hostPath);
+            if (fileInfo.Exists)
             {
-                size = 65536;
+                var length = fileInfo.Length;
+                size = length < 0 ? 0UL : unchecked((ulong)length);
                 return true;
             }
 
-            if (!File.Exists(hostPath))
+            if (!new DirectoryInfo(hostPath).Exists)
             {
                 return false;
             }
 
-            var length = new FileInfo(hostPath).Length;
+            size = 65536;
-            size = length < 0 ? 0UL : unchecked((ulong)length);
             return true;
         }
         catch
@@ -5542,6 +5842,120 @@ public static class KernelMemoryCompatExports
         Console.Error.WriteLine($"[LOADER][TRACE] {operation} path='{path}' {detail}");
     }
 
+    private static void LogUniqueStatTrace(string guestPath, string hostPath, bool found)
+    {
+        if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_IO"), "1", StringComparison.Ordinal))
+        {
+            return;
+        }
+
+        var result = found ? "found" : "not_found";
+        lock (_ioTraceGate)
+        {
+            if (!_tracedStatResults.Add($"{result}\0{guestPath}"))
+            {
+                return;
+            }
+        }
+
+        LogIoTrace("stat", guestPath, $"host='{hostPath}' result={result}");
+    }
+
+    private static string? GetNegativeStatCacheKey(string guestPath)
+    {
+        var normalized = NormalizeGuestStatCachePath(guestPath);
+        return IsReadOnlyGuestStatPath(normalized) ? normalized : null;
+    }
+
+    private static string? NormalizeGuestStatCachePath(string guestPath)
+    {
+        var normalized = guestPath.Replace('\\', '/').TrimEnd('/');
+        if (normalized.Length == 0)
+        {
+            return null;
+        }
+
+        if (normalized[0] != '/')
+        {
+            normalized = "/" + normalized;
+        }
+
+        return normalized;
+    }
+
+    private static bool IsReadOnlyGuestStatPath(string? normalizedGuestPath) =>
+        normalizedGuestPath is not null &&
+        (string.Equals(normalizedGuestPath, "/app0", StringComparison.OrdinalIgnoreCase) ||
+         normalizedGuestPath.StartsWith("/app0/", StringComparison.OrdinalIgnoreCase) ||
+         string.Equals(normalizedGuestPath, "/hostapp", StringComparison.OrdinalIgnoreCase) ||
+         normalizedGuestPath.StartsWith("/hostapp/", StringComparison.OrdinalIgnoreCase) ||
+         string.Equals(normalizedGuestPath, "/devlog/app", StringComparison.OrdinalIgnoreCase) ||
+         normalizedGuestPath.StartsWith("/devlog/app/", StringComparison.OrdinalIgnoreCase) ||
+         string.Equals(normalizedGuestPath, "/temp0", StringComparison.OrdinalIgnoreCase) ||
+         normalizedGuestPath.StartsWith("/temp0/", StringComparison.OrdinalIgnoreCase) ||
+         string.Equals(normalizedGuestPath, "/download0", StringComparison.OrdinalIgnoreCase) ||
+         normalizedGuestPath.StartsWith("/download0/", StringComparison.OrdinalIgnoreCase));
+
+    private static bool IsNegativeStatCached(string cacheKey)
+    {
+        lock (_statCacheGate)
+        {
+            return _negativeStatCache.Contains(cacheKey);
+        }
+    }
+
+    private static void AddNegativeStatCache(string cacheKey)
+    {
+        lock (_statCacheGate)
+        {
+            _negativeStatCache.Add(cacheKey);
+        }
+    }
+
+    private static void RemoveNegativeStatCache(string cacheKey)
+    {
+        lock (_statCacheGate)
+        {
+            _negativeStatCache.Remove(cacheKey);
+        }
+    }
+
+    private static void AddNegativeStatCacheForGuestPath(string guestPath)
+    {
+        var cacheKey = GetNegativeStatCacheKey(guestPath);
+        if (cacheKey is not null)
+        {
+            AddNegativeStatCache(cacheKey);
+        }
+    }
+
+    private static void InvalidateNegativeStatCacheForPathAndAncestors(string guestPath)
+    {
+        var normalized = NormalizeGuestStatCachePath(guestPath);
+        if (normalized is null)
+        {
+            return;
+        }
+
+        lock (_statCacheGate)
+        {
+            var current = normalized;
+            while (true)
+            {
+                _negativeStatCache.Remove(current);
+                var slash = current.LastIndexOf('/');
+                if (slash <= 0)
+                {
+                    break;
+                }
+
+                current = current[..slash];
+            }
+
+            _negativeStatCache.Remove("/");
+        }
+    }
+
     private static string PreviewIoBytes(byte[] buffer, int count, int maxBytes)
     {
         if (count <= 0)

src/SharpEmu.Libs/Kernel/KernelPthreadCompatExports.cs

@@ -1,6 +1,7 @@
 // Copyright (C) 2026 SharpEmu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+using System.Collections.Concurrent;
 using SharpEmu.HLE;
 using System.Buffers.Binary;
 using System.Threading;
@@ -10,7 +11,7 @@ namespace SharpEmu.Libs.Kernel;
 
 public static class KernelPthreadCompatExports
 {
-    private const int MutexTypeDefault = 1;
+    private const int MutexTypeDefault = 0;
     private const int MutexTypeErrorCheck = 1;
     private const int MutexTypeRecursive = 2;
     private const int MutexTypeNormal = 3;
@@ -25,11 +26,18 @@ public static class KernelPthreadCompatExports
     private const int PthreadOnceDone = 2;
 
     private static readonly object _stateGate = new();
-    private static readonly Dictionary<ulong, PthreadMutexState> _mutexStates = new();
+    private static readonly ConcurrentDictionary<ulong, PthreadMutexState> _mutexStates = new();
     private static readonly Dictionary<ulong, PthreadMutexAttrState> _mutexAttrStates = new();
     private static readonly Dictionary<ulong, PthreadCondState> _condStates = new();
     private static readonly Dictionary<ulong, object> _onceGates = new();
     private static readonly HashSet<ulong> _condAttrStates = new();
+    private static readonly bool _tracePthreads =
+        string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_PTHREADS"), "1", StringComparison.Ordinal);
+    private static readonly bool _tracePthreadConds =
+        _tracePthreads ||
+        string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_PTHREAD_CONDS"), "1", StringComparison.Ordinal);
+    private static readonly HashSet<ulong>? _tracePthreadMutexFilter = ParseTraceAddressFilter(
+        Environment.GetEnvironmentVariable("SHARPEMU_LOG_PTHREAD_MUTEX_FILTER"));
 
     private sealed class PthreadMutexState
     {
@@ -40,6 +48,12 @@ public static class KernelPthreadCompatExports
         public int Protocol { get; set; }
     }
 
+    private sealed class PthreadMutexWaiter
+    {
+        public required ulong ThreadId { get; init; }
+        public int Reserved;
+    }
+
     private sealed class PthreadCondState
     {
         public object SyncRoot { get; } = new();
@@ -463,19 +477,13 @@ public static class KernelPthreadCompatExports
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
         }
 
-        lock (_stateGate)
+        _mutexStates[mutexAddress] = state;
-        {
+        _mutexStates[handle] = state;
-            _mutexStates[mutexAddress] = state;
-            _mutexStates[handle] = state;
-        }
 
-        if (!ctx.TryWriteUInt64(mutexAddress, handle))
+        if (!KernelMemoryCompatExports.TryWriteUInt64Compat(ctx, mutexAddress, handle))
         {
-            lock (_stateGate)
+            _mutexStates.TryRemove(mutexAddress, out _);
-            {
+            _mutexStates.TryRemove(handle, out _);
-                _mutexStates.Remove(mutexAddress);
-                _mutexStates.Remove(handle);
-            }
 
             state.Semaphore.Dispose();
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
@@ -492,15 +500,10 @@ public static class KernelPthreadCompatExports
         }
 
         var resolvedAddress = ResolveMutexHandle(ctx, mutexAddress);
-        PthreadMutexState? state;
+        _mutexStates.TryRemove(resolvedAddress, out var state);
-        lock (_stateGate)
+        if (resolvedAddress != mutexAddress)
         {
-            _mutexStates.TryGetValue(resolvedAddress, out state);
+            _mutexStates.TryRemove(mutexAddress, out _);
-            _mutexStates.Remove(resolvedAddress);
-            if (resolvedAddress != mutexAddress)
-            {
-                _mutexStates.Remove(mutexAddress);
-            }
         }
 
         if (state is null)
@@ -508,7 +511,7 @@ public static class KernelPthreadCompatExports
             return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
         }
 
-        _ = ctx.TryWriteUInt64(mutexAddress, 0);
+        _ = KernelMemoryCompatExports.TryWriteUInt64Compat(ctx, mutexAddress, 0);
         state.Semaphore.Dispose();
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
@@ -538,7 +541,7 @@ public static class KernelPthreadCompatExports
                     return (int)OrbisGen2Result.ORBIS_GEN2_OK;
                 }
 
-                if (state.Type is MutexTypeNormal or MutexTypeAdaptiveNp)
+                if (state.Type is MutexTypeDefault or MutexTypeNormal or MutexTypeAdaptiveNp)
                 {
                     if (tryOnly)
                     {
@@ -563,15 +566,33 @@ public static class KernelPthreadCompatExports
             }
         }
 
-        var acquired = true;
+        var acquired = state.Semaphore.Wait(0);
-        if (tryOnly)
+        if (!acquired)
         {
-            acquired = state.Semaphore.Wait(0);
+            // Guest-thread blocking for pthread_mutex_lock is currently disabled.
-        }
+            // Demon's Souls deadlocks during PS5SyncEvent initialization.
-        else
+            /* var waiter = new PthreadMutexWaiter { ThreadId = currentThreadId };
-        {
+            if (!tryOnly &&
-            state.Semaphore.Wait();
+                GuestThreadExecution.IsGuestThread &&
+                GuestThreadExecution.TryGetCurrentImportCallFrame(out _) &&
+                GuestThreadExecution.RequestCurrentThreadBlock(
+                    ctx,
+                    "pthread_mutex_lock",
+                    GetMutexWakeKey(resolvedAddress),
+                    () => CompleteBlockedMutexLock(ctx, mutexAddress, resolvedAddress, state, waiter),
+                    () => TryReserveBlockedMutexLock(ctx, mutexAddress, resolvedAddress, state, waiter)))
+            {
+                TracePthreadMutex(ctx, "lock-block", mutexAddress, resolvedAddress, state, currentThreadId, (int)OrbisGen2Result.ORBIS_GEN2_OK);
+                return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+            } */
+
+            if (!tryOnly)
+            {
+                state.Semaphore.Wait();
+                acquired = true;
+            }
         }
+
         if (!acquired)
         {
             TracePthreadMutex(ctx, tryOnly ? "trylock" : "lock", mutexAddress, resolvedAddress, state, currentThreadId, (int)OrbisGen2Result.ORBIS_GEN2_ERROR_BUSY);
@@ -630,6 +651,7 @@ public static class KernelPthreadCompatExports
             try
             {
                 state.Semaphore.Release();
+                _ = GuestThreadExecution.Scheduler?.WakeBlockedThreads(GetMutexWakeKey(resolvedAddress), 1);
             }
             catch (SemaphoreFullException)
             {
@@ -666,7 +688,7 @@ public static class KernelPthreadCompatExports
             _mutexAttrStates[handle] = initialState;
         }
 
-        if (!ctx.TryWriteUInt64(attrAddress, handle))
+        if (!KernelMemoryCompatExports.TryWriteUInt64Compat(ctx, attrAddress, handle))
         {
             lock (_stateGate)
             {
@@ -765,22 +787,16 @@ public static class KernelPthreadCompatExports
             return 0;
         }
 
-        lock (_stateGate)
+        if (_mutexStates.ContainsKey(mutexAddress))
         {
-            if (_mutexStates.ContainsKey(mutexAddress))
+            return mutexAddress;
-            {
-                return mutexAddress;
-            }
         }
 
-        if (ctx.TryReadUInt64(mutexAddress, out var pointedHandle) && pointedHandle != 0)
+        if (KernelMemoryCompatExports.TryReadUInt64Compat(ctx, mutexAddress, out var pointedHandle) && pointedHandle != 0)
         {
-            lock (_stateGate)
+            if (_mutexStates.ContainsKey(pointedHandle))
             {
-                if (_mutexStates.ContainsKey(pointedHandle))
+                return pointedHandle;
-                {
-                    return pointedHandle;
-                }
             }
         }
 
@@ -796,16 +812,13 @@ public static class KernelPthreadCompatExports
             return false;
         }
 
-        lock (_stateGate)
+        if (_mutexStates.TryGetValue(mutexAddress, out state))
         {
-            if (_mutexStates.TryGetValue(mutexAddress, out state))
+            resolvedAddress = mutexAddress;
-            {
+            return true;
-                resolvedAddress = mutexAddress;
-                return true;
-            }
         }
 
-        if (!ctx.TryReadUInt64(mutexAddress, out var pointedHandle))
+        if (!KernelMemoryCompatExports.TryReadUInt64Compat(ctx, mutexAddress, out var pointedHandle))
         {
             return false;
         }
@@ -817,14 +830,11 @@ public static class KernelPthreadCompatExports
 
         if (pointedHandle != 0)
         {
-            lock (_stateGate)
+            if (_mutexStates.TryGetValue(pointedHandle, out state))
             {
-                if (_mutexStates.TryGetValue(pointedHandle, out state))
+                _mutexStates.TryAdd(mutexAddress, state);
-                {
+                resolvedAddress = pointedHandle;
-                    _mutexStates[mutexAddress] = state;
+                return true;
-                    resolvedAddress = pointedHandle;
-                    return true;
-                }
             }
 
             resolvedAddress = pointedHandle;
@@ -847,7 +857,7 @@ public static class KernelPthreadCompatExports
             return 0;
         }
 
-        if (ctx.TryReadUInt64(attrAddress, out var pointedHandle) && pointedHandle != 0)
+        if (KernelMemoryCompatExports.TryReadUInt64Compat(ctx, attrAddress, out var pointedHandle) && pointedHandle != 0)
         {
             lock (_stateGate)
             {
@@ -900,7 +910,7 @@ public static class KernelPthreadCompatExports
             }
         }
 
-        if (ctx.TryReadUInt64(condAddress, out var pointedHandle) && pointedHandle != 0)
+        if (KernelMemoryCompatExports.TryReadUInt64Compat(ctx, condAddress, out var pointedHandle) && pointedHandle != 0)
         {
             lock (_stateGate)
             {
@@ -932,7 +942,7 @@ public static class KernelPthreadCompatExports
             }
         }
 
-        if (ctx is null || !ctx.TryReadUInt64(condAddress, out var pointedHandle))
+        if (ctx is null || !KernelMemoryCompatExports.TryReadUInt64Compat(ctx, condAddress, out var pointedHandle))
         {
             return false;
         }
@@ -971,7 +981,7 @@ public static class KernelPthreadCompatExports
             _condStates[handle] = createdState;
         }
 
-        if (!ctx.TryWriteUInt64(condAddress, handle))
+        if (!KernelMemoryCompatExports.TryWriteUInt64Compat(ctx, condAddress, handle))
         {
             lock (_stateGate)
             {
@@ -1035,7 +1045,7 @@ public static class KernelPthreadCompatExports
             _condStates[handle] = state;
         }
 
-        if (!ctx.TryWriteUInt64(condAddress, handle))
+        if (!KernelMemoryCompatExports.TryWriteUInt64Compat(ctx, condAddress, handle))
         {
             lock (_stateGate)
             {
@@ -1066,7 +1076,7 @@ public static class KernelPthreadCompatExports
             }
         }
 
-        _ = ctx.TryWriteUInt64(condAddress, 0);
+        _ = KernelMemoryCompatExports.TryWriteUInt64Compat(ctx, condAddress, 0);
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
@@ -1202,6 +1212,63 @@ public static class KernelPthreadCompatExports
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
+    private static string GetMutexWakeKey(ulong resolvedMutexAddress) =>
+        $"pthread_mutex:0x{resolvedMutexAddress:X16}";
+
+    private static bool TryReserveBlockedMutexLock(
+        CpuContext ctx,
+        ulong mutexAddress,
+        ulong resolvedAddress,
+        PthreadMutexState state,
+        PthreadMutexWaiter waiter)
+    {
+        lock (state)
+        {
+            if (state.OwnerThreadId != 0 || state.RecursionCount != 0)
+            {
+                TracePthreadMutex(ctx, "lock-reserve-busy", mutexAddress, resolvedAddress, state, waiter.ThreadId, (int)OrbisGen2Result.ORBIS_GEN2_ERROR_BUSY);
+                return false;
+            }
+
+            state.OwnerThreadId = waiter.ThreadId;
+            state.RecursionCount = 1;
+            Interlocked.Exchange(ref waiter.Reserved, 1);
+        }
+
+        TracePthreadMutex(ctx, "lock-reserve", mutexAddress, resolvedAddress, state, waiter.ThreadId, (int)OrbisGen2Result.ORBIS_GEN2_OK);
+        return true;
+    }
+
+    private static int CompleteBlockedMutexLock(
+        CpuContext ctx,
+        ulong mutexAddress,
+        ulong resolvedAddress,
+        PthreadMutexState state,
+        PthreadMutexWaiter waiter)
+    {
+        var currentThreadId = KernelPthreadState.GetCurrentThreadHandle();
+        if (Interlocked.Exchange(ref waiter.Reserved, 0) == 1)
+        {
+            TracePthreadMutex(ctx, "lock-resume", mutexAddress, resolvedAddress, state, currentThreadId, (int)OrbisGen2Result.ORBIS_GEN2_OK);
+            return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+        }
+
+        if (!state.Semaphore.Wait(0))
+        {
+            TracePthreadMutex(ctx, "lock-resume-busy", mutexAddress, resolvedAddress, state, currentThreadId, (int)OrbisGen2Result.ORBIS_GEN2_ERROR_BUSY);
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_BUSY;
+        }
+
+        lock (state)
+        {
+            state.OwnerThreadId = currentThreadId;
+            state.RecursionCount = 1;
+        }
+
+        TracePthreadMutex(ctx, "lock-resume", mutexAddress, resolvedAddress, state, currentThreadId, (int)OrbisGen2Result.ORBIS_GEN2_OK);
+        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
+    }
+
     private static TimeSpan GetCondWaitTimeout(uint timeoutUsec)
     {
         if (timeoutUsec == 0)
@@ -1313,13 +1380,10 @@ public static class KernelPthreadCompatExports
             _mutexStates[handle] = createdState;
         }
 
-        if (!ctx.TryWriteUInt64(mutexAddress, handle))
+        if (!KernelMemoryCompatExports.TryWriteUInt64Compat(ctx, mutexAddress, handle))
         {
-            lock (_stateGate)
+            _mutexStates.TryRemove(mutexAddress, out _);
-            {
+            _mutexStates.TryRemove(handle, out _);
-                _mutexStates.Remove(mutexAddress);
-                _mutexStates.Remove(handle);
-            }
 
             resolvedAddress = 0;
             state = null;
@@ -1357,13 +1421,13 @@ public static class KernelPthreadCompatExports
 
     private static void TracePthreadMutex(CpuContext ctx, string operation, ulong mutexAddress, ulong resolvedAddress, PthreadMutexState? state, ulong currentThreadId, int result)
     {
-        if (!ShouldTracePthread())
+        if (!ShouldTracePthreadMutex(mutexAddress, resolvedAddress))
         {
             return;
         }
 
-        _ = ctx.TryReadUInt64(mutexAddress, out var guestWord0);
+        _ = KernelMemoryCompatExports.TryReadUInt64Compat(ctx, mutexAddress, out var guestWord0);
-        _ = ctx.TryReadUInt64(mutexAddress + 8, out var guestWord1);
+        _ = KernelMemoryCompatExports.TryReadUInt64Compat(ctx, mutexAddress + 8, out var guestWord1);
         Console.Error.WriteLine(
             $"[LOADER][TRACE] pthread_{operation}: mutex=0x{mutexAddress:X16} resolved=0x{resolvedAddress:X16} " +
             $"guest[0]=0x{guestWord0:X16} guest[8]=0x{guestWord1:X16} " +
@@ -1373,7 +1437,7 @@ public static class KernelPthreadCompatExports
 
     private static void TracePthreadCond(string operation, ulong condAddress, ulong mutexAddress, PthreadCondState? state, bool timed, int result)
     {
-        if (!ShouldTracePthread())
+        if (!_tracePthreadConds)
         {
             return;
         }
@@ -1385,6 +1449,45 @@ public static class KernelPthreadCompatExports
 
     private static bool ShouldTracePthread()
     {
-        return string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_PTHREADS"), "1", StringComparison.Ordinal);
+        return _tracePthreads;
+    }
+
+    private static bool ShouldTracePthreadMutex(ulong mutexAddress, ulong resolvedAddress)
+    {
+        if (_tracePthreadMutexFilter is null || _tracePthreadMutexFilter.Count == 0)
+        {
+            return _tracePthreads;
+        }
+
+        return _tracePthreadMutexFilter.Contains(mutexAddress) ||
+            _tracePthreadMutexFilter.Contains(resolvedAddress);
+    }
+
+    private static HashSet<ulong>? ParseTraceAddressFilter(string? filter)
+    {
+        if (string.IsNullOrWhiteSpace(filter))
+        {
+            return null;
+        }
+
+        var addresses = new HashSet<ulong>();
+        foreach (var token in filter.Split(new[] { ',', ';', ' ' }, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries))
+        {
+            var normalized = token.StartsWith("0x", StringComparison.OrdinalIgnoreCase)
+                ? token[2..]
+                : token;
+            normalized = normalized.TrimStart('0');
+
+            if (ulong.TryParse(
+                    normalized.Length == 0 ? "0" : normalized,
+                    System.Globalization.NumberStyles.HexNumber,
+                    System.Globalization.CultureInfo.InvariantCulture,
+                    out var address))
+            {
+                addresses.Add(address);
+            }
+        }
+
+        return addresses.Count == 0 ? null : addresses;
     }
 }

src/SharpEmu.Libs/Kernel/KernelPthreadExtendedCompatExports.cs

@@ -3,6 +3,7 @@
 
 using SharpEmu.HLE;
 using System.Buffers.Binary;
+using System.Collections.Concurrent;
 using System.Text;
 using System.Threading;
 using System.Diagnostics.CodeAnalysis;
@@ -26,12 +27,12 @@ public static class KernelPthreadExtendedCompatExports
     private static readonly Dictionary<ulong, ThreadState> _threadStates = new();
     private static readonly Dictionary<ulong, PthreadAttrState> _attrStates = new();
     private static readonly Dictionary<ulong, PthreadRwlockState> _rwlockStates = new();
-    private static readonly Dictionary<int, TlsKeyState> _tlsKeys = new();
+    private static readonly ConcurrentDictionary<int, TlsKeyState> _tlsKeys = new();
     private static int _nextTlsKey = 1;
     private static long _nextSyntheticRwlockHandleId = 1;
     private static long _nextSyntheticPthreadAttrHandleId = 1;
 
-    private static readonly Dictionary<ulong, Dictionary<int, ulong>> _threadLocalSpecific = new();
+    private static readonly ConcurrentDictionary<ulong, ConcurrentDictionary<int, ulong>> _threadLocalSpecific = new();
 
     private sealed class ThreadState
     {
@@ -793,7 +794,7 @@ public static class KernelPthreadExtendedCompatExports
             _rwlockStates[syntheticHandle] = rwlock;
         }
 
-        _ = ctx.TryWriteUInt64(rwlockAddress, syntheticHandle);
+        _ = KernelMemoryCompatExports.TryWriteUInt64Compat(ctx, rwlockAddress, syntheticHandle);
         ctx[CpuRegister.Rax] = 0;
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
@@ -847,7 +848,7 @@ public static class KernelPthreadExtendedCompatExports
             }
         }
 
-        _ = ctx.TryWriteUInt64(rwlockAddress, 0);
+        _ = KernelMemoryCompatExports.TryWriteUInt64Compat(ctx, rwlockAddress, 0);
         ctx[CpuRegister.Rax] = 0;
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
@@ -959,15 +960,13 @@ public static class KernelPthreadExtendedCompatExports
         }
 
         int key;
-        lock (_stateGate)
+        while (true)
         {
-            while (_tlsKeys.ContainsKey(_nextTlsKey))
+            key = Interlocked.Increment(ref _nextTlsKey) - 1;
+            if (_tlsKeys.TryAdd(key, new TlsKeyState(destructor)))
             {
-                _nextTlsKey++;
+                break;
             }
-
-            key = _nextTlsKey++;
-            _tlsKeys[key] = new TlsKeyState(destructor);
         }
 
         if (!TryWriteInt32(ctx, outKeyAddress, key))
@@ -994,17 +993,14 @@ public static class KernelPthreadExtendedCompatExports
     public static int PosixPthreadKeyDelete(CpuContext ctx)
     {
         var key = unchecked((int)ctx[CpuRegister.Rdi]);
-        lock (_stateGate)
+        if (!_tlsKeys.TryRemove(key, out _))
         {
-            if (!_tlsKeys.Remove(key))
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
-            {
+        }
-                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
-            }
 
-            foreach (var entry in _threadLocalSpecific)
+        foreach (var values in _threadLocalSpecific.Values)
-            {
+        {
-                entry.Value.Remove(key);
+            values.TryRemove(key, out _);
-            }
         }
 
         ctx[CpuRegister.Rax] = 0;
@@ -1028,22 +1024,15 @@ public static class KernelPthreadExtendedCompatExports
         var key = unchecked((int)ctx[CpuRegister.Rdi]);
         var value = ctx[CpuRegister.Rsi];
         var currentThreadHandle = KernelPthreadState.GetCurrentThreadHandle();
-        lock (_stateGate)
+        if (!_tlsKeys.ContainsKey(key))
         {
-            if (!_tlsKeys.TryGetValue(key, out _))
+            return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
-            {
-                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_NOT_FOUND;
-            }
-
-            if (!_threadLocalSpecific.TryGetValue(currentThreadHandle, out var values))
-            {
-                values = new Dictionary<int, ulong>();
-                _threadLocalSpecific[currentThreadHandle] = values;
-            }
-
-            values[key] = value;
         }
 
+        var values = _threadLocalSpecific.GetOrAdd(
+            currentThreadHandle,
+            static _ => new ConcurrentDictionary<int, ulong>());
+        values[key] = value;
         ctx[CpuRegister.Rax] = 0;
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
@@ -1065,19 +1054,16 @@ public static class KernelPthreadExtendedCompatExports
         var key = unchecked((int)ctx[CpuRegister.Rdi]);
         var currentThreadHandle = KernelPthreadState.GetCurrentThreadHandle();
         ulong value = 0;
-        lock (_stateGate)
+        if (!_tlsKeys.ContainsKey(key))
         {
-            if (!_tlsKeys.TryGetValue(key, out _))
+            ctx[CpuRegister.Rax] = 0;
-            {
+            return (int)OrbisGen2Result.ORBIS_GEN2_OK;
-                ctx[CpuRegister.Rax] = 0;
+        }
-                return (int)OrbisGen2Result.ORBIS_GEN2_OK;
-            }
 
-            if (_threadLocalSpecific.TryGetValue(currentThreadHandle, out var values) &&
+        if (_threadLocalSpecific.TryGetValue(currentThreadHandle, out var values) &&
-                values.TryGetValue(key, out var storedValue))
+            values.TryGetValue(key, out var storedValue))
-            {
+        {
-                value = storedValue;
+            value = storedValue;
-            }
         }
 
         ctx[CpuRegister.Rax] = value;
@@ -1163,7 +1149,7 @@ public static class KernelPthreadExtendedCompatExports
             }
         }
 
-        if (ctx.TryReadUInt64(rwlockAddress, out var pointedHandle) && pointedHandle != 0)
+        if (KernelMemoryCompatExports.TryReadUInt64Compat(ctx, rwlockAddress, out var pointedHandle) && pointedHandle != 0)
         {
             lock (_stateGate)
             {
@@ -1195,7 +1181,7 @@ public static class KernelPthreadExtendedCompatExports
             }
         }
 
-        if (!ctx.TryReadUInt64(rwlockAddress, out var pointedHandle))
+        if (!KernelMemoryCompatExports.TryReadUInt64Compat(ctx, rwlockAddress, out var pointedHandle))
         {
             return false;
         }
@@ -1230,7 +1216,7 @@ public static class KernelPthreadExtendedCompatExports
             _rwlockStates[syntheticHandle] = createdRwlock;
         }
 
-        _ = ctx.TryWriteUInt64(rwlockAddress, syntheticHandle);
+        _ = KernelMemoryCompatExports.TryWriteUInt64Compat(ctx, rwlockAddress, syntheticHandle);
         resolvedAddress = syntheticHandle;
         rwlock = createdRwlock;
         return true;

src/SharpEmu.Libs/Kernel/KernelPthreadState.cs

@@ -1,6 +1,7 @@
 // Copyright (C) 2026 SharpEmu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+using System.Collections.Concurrent;
 using System.Runtime.InteropServices;
 using System.Threading;
 using SharpEmu.HLE;
@@ -11,8 +12,7 @@ internal static class KernelPthreadState
 {
     private const int ThreadObjectSize = 0x1000;
 
-    private static readonly object Gate = new();
+    private static readonly ConcurrentDictionary<ulong, ThreadIdentity> Threads = new();
-    private static readonly Dictionary<ulong, ThreadIdentity> Threads = new();
     private static readonly byte[] ZeroThreadObject = new byte[ThreadObjectSize];
     private static long _nextUniqueThreadId = 1;
 
@@ -56,10 +56,7 @@ internal static class KernelPthreadState
 
     internal static bool TryGetThreadIdentity(ulong threadHandle, out ThreadIdentity identity)
     {
-        lock (Gate)
+        return Threads.TryGetValue(threadHandle, out identity);
-        {
-            return Threads.TryGetValue(threadHandle, out identity);
-        }
     }
 
     private static void EnsureCurrentThreadRegistered()
@@ -81,10 +78,7 @@ internal static class KernelPthreadState
         Marshal.Copy(ZeroThreadObject, 0, pointer, ThreadObjectSize);
 
         var handle = unchecked((ulong)pointer.ToInt64());
-        lock (Gate)
+        Threads[handle] = new ThreadIdentity(uniqueId, string.IsNullOrWhiteSpace(name) ? $"Thread-{uniqueId:X}" : name);
-        {
-            Threads[handle] = new ThreadIdentity(uniqueId, string.IsNullOrWhiteSpace(name) ? $"Thread-{uniqueId:X}" : name);
-        }
 
         return handle;
     }

src/SharpEmu.Libs/Kernel/KernelRuntimeCompatExports.cs

@@ -57,6 +57,13 @@ public static class KernelRuntimeCompatExports
     private static readonly (ulong Base, ulong Size)[] _prtApertures = new (ulong Base, ulong Size)[3];
     private static int _stackChkFailCount;
     private static long _usleepTraceCount;
+    private static readonly bool _traceUsleep =
+        string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_USLEEP"), "1", StringComparison.Ordinal);
+    private static readonly bool _traceGuestThreads =
+        string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_GUEST_THREADS"), "1", StringComparison.Ordinal);
+
+    [ThreadStatic]
+    private static int _shortUsleepCount;
 
     [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
     private delegate ulong RdtscDelegate();
@@ -80,10 +87,20 @@ public static class KernelRuntimeCompatExports
 
         if (micros < 1000)
         {
-            Thread.Yield();
+            // Guest worker pools use usleep(1) as a polling backoff. Periodically
+            // relinquish a full host time slice so spin workers cannot starve producers.
+            if ((++_shortUsleepCount & 31) == 0)
+            {
+                Thread.Sleep(1);
+            }
+            else
+            {
+                Thread.Yield();
+            }
         }
         else
         {
+            _shortUsleepCount = 0;
             var sleepMilliseconds = (int)Math.Min((micros + 999UL) / 1000UL, int.MaxValue);
             Thread.Sleep(sleepMilliseconds);
         }
@@ -94,7 +111,7 @@ public static class KernelRuntimeCompatExports
 
     private static void TraceUsleepSpin(CpuContext ctx, ulong micros)
     {
-        if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_USLEEP"), "1", StringComparison.Ordinal))
+        if (!_traceUsleep)
         {
             return;
         }
@@ -142,6 +159,19 @@ public static class KernelRuntimeCompatExports
 
         Console.Error.WriteLine(
             $"[LOADER][TRACE] usleep#{count}: usec={micros} ret=0x{returnRip:X16} caller={callerReturnText} thread=0x{thread:X16} fiber=0x{fiber:X16} rbx=0x{rbx:X16} lock@+F78=0x{lockAddress:X16}:{lockText} r12=0x{r12:X16} scheduler@+8={schedulerText} r13=0x{r13:X16}:{waitValueText} r14=0x{ctx[CpuRegister.R14]:X16} r15=0x{ctx[CpuRegister.R15]:X16}");
+
+        if (count % 100000 == 0 &&
+            _traceGuestThreads &&
+            GuestThreadExecution.Scheduler is { } scheduler)
+        {
+            foreach (var snapshot in scheduler.SnapshotThreads())
+            {
+                Console.Error.WriteLine(
+                    $"[LOADER][TRACE] guest_thread.snapshot handle=0x{snapshot.ThreadHandle:X16} name='{snapshot.Name}' " +
+                    $"state={snapshot.State} imports={snapshot.ImportCount} nid={snapshot.LastImportNid ?? "none"} " +
+                    $"ret=0x{snapshot.LastReturnRip:X16} block={snapshot.BlockReason ?? "none"}");
+            }
+        }
     }
 
     [SysAbiExport(
@@ -581,19 +611,16 @@ public static class KernelRuntimeCompatExports
     public static int ErrorAddress(CpuContext ctx)
     {
         var address = GetTlsScratchAddress(ctx, TlsErrnoOffset);
-        if (address != 0)
-        {
-            Span<byte> zero = stackalloc byte[sizeof(int)];
-            if (!ctx.Memory.TryWrite(address, zero))
-            {
-                return (int)OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT;
-            }
-        }
-
         ctx[CpuRegister.Rax] = address;
         return (int)OrbisGen2Result.ORBIS_GEN2_OK;
     }
 
+    internal static bool TrySetErrno(CpuContext ctx, int value)
+    {
+        var address = GetTlsScratchAddress(ctx, TlsErrnoOffset);
+        return address != 0 && TryWriteInt32(ctx, address, value);
+    }
+
     [SysAbiExport(
         Nid = "bnZxYgAFeA0",
         ExportName = "sceKernelGetSanitizerNewReplaceExternal",
@@ -1505,30 +1532,40 @@ public static class KernelRuntimeCompatExports
             ulong.TryParse(overrideHzText, out var overrideHz) &&
             overrideHz >= minSane)
         {
+            TraceKernelTscFrequency("env", overrideHz);
             return overrideHz;
         }
 
-        if (TryResolveCpuidTscFrequency(out ulong cpuidHz) && cpuidHz >= minSane)
-        {
-            return cpuidHz;
-        }
-
         if (TryCalibrateHostTscFrequency(out ulong calibratedHz) && calibratedHz >= minSane)
         {
+            TraceKernelTscFrequency("calibrated-rdtsc", calibratedHz);
             return calibratedHz;
         }
 
+        if (TryResolveCpuidTscFrequency(out ulong cpuidHz) && cpuidHz >= minSane)
+        {
+            TraceKernelTscFrequency("cpuid", cpuidHz);
+            return cpuidHz;
+        }
+
         var hostQpc = Stopwatch.Frequency > 0
             ? unchecked((ulong)Stopwatch.Frequency)
             : DefaultKernelTscFrequency;
         if (hostQpc >= minSane)
         {
+            TraceKernelTscFrequency("qpc", hostQpc);
             return hostQpc;
         }
 
+        TraceKernelTscFrequency("default", DefaultKernelTscFrequency);
         return DefaultKernelTscFrequency;
     }
 
+    private static void TraceKernelTscFrequency(string source, ulong frequencyHz)
+    {
+        Console.Error.WriteLine($"[LOADER][INFO] Kernel TSC frequency: {frequencyHz} Hz ({source})");
+    }
+
     private static bool TryResolveCpuidTscFrequency(out ulong frequencyHz)
     {
         frequencyHz = 0;
@@ -1788,7 +1825,7 @@ public static class KernelRuntimeCompatExports
             }
 
             var invokeArgs = allocateAtHasAllowAlternativeArg
-                ? new object[] { desiredAddress, length, false, false }
+                ? new object[] { desiredAddress, length, false, allowSearch }
                 : new object[] { desiredAddress, length, false };
             var result = allocateAt.Invoke(memoryObject, invokeArgs);
             if (result is not ulong allocated || allocated == 0)

src/SharpEmu.Libs/Kernel/KernelSemaphoreCompatExports.cs

@@ -120,7 +120,7 @@ public static class KernelSemaphoreCompatExports
                 return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_TIMED_OUT);
             }
 
-            if (!GuestThreadExecution.RequestCurrentThreadBlock("sceKernelWaitSema"))
+            if (!GuestThreadExecution.RequestCurrentThreadBlock(ctx, "sceKernelWaitSema"))
             {
                 TraceSemaphore($"wait-would-block handle=0x{handle:X8} name='{semaphore.Name}' need={needCount} count={semaphore.Count}");
                 return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_TRY_AGAIN);