[*] Preemptive GetOverlappedResult fast-paths under WaitMultiple2 that rely on the alertable yield under next read/write cannot be trusted if the read count is zero.

Direct IO-specific quirk?
Windows 7 specific quirk?
Direct IO under Win7 specific quirk?
idk, but this fixes it

Source/IO/FS/Async.NT.cpp

@@ -279,6 +279,14 @@ namespace Aurora::IO::FS
         this->overlap.hEvent = this->event = CreateEventW(nullptr, true, false, nullptr);
         return this->overlap.hEvent != INVALID_HANDLE_VALUE;
     }
+
+    void NtAsyncFileTransaction::ResetAIO()
+    {
+        auto hEvent = this->overlap.hEvent;
+        AuResetMember(this->overlap);
+        this->overlap.hEvent = hEvent;
+    }
+
     static bool TranslateNtStatus(NtAsyncFileTransaction *that, BOOL val)
     {
         auto er = GetLastError();
@@ -347,12 +355,9 @@ namespace Aurora::IO::FS
 
     bool NtAsyncFileTransaction::IDontWannaUsePorts()
     {
-        // TODO: maybe we could use a semaphore counter of read attempts
-        // to allow APC callbacks to drag behind
-
         if (AuExchange(this->pPin, AuSharedFromThis()))
         {
-            while (SleepEx(100, true) == WAIT_IO_COMPLETION)
+            while (SleepEx(0, true) == WAIT_IO_COMPLETION)
             {
 
             }
@@ -407,6 +412,7 @@ namespace Aurora::IO::FS
         this->dwLastAbstractOffset = offset;
         this->dwLastBytes = 0;
 
+        this->ResetAIO();
         this->overlap.Offset     = AuBitsToLower(offset);
         this->overlap.OffsetHigh = AuBitsToHigher(offset);
        
@@ -453,7 +459,8 @@ namespace Aurora::IO::FS
         this->dwLastBytes = 0;
         this->dwLastAbstractStat   = memoryView->length;
         this->dwLastAbstractOffset = offset;
-        
+
+        this->ResetAIO();
         this->overlap.Offset     = AuBitsToLower(offset);
         this->overlap.OffsetHigh = AuBitsToHigher(offset);
         auto ret = ::WriteFileEx(this->pHandle_->writeHandle, memoryView->ptr, memoryView->length, &this->overlap, FileOperationCompletion);
@@ -533,10 +540,10 @@ namespace Aurora::IO::FS
             if (::GetOverlappedResult(this->pHandle_->handle,
                                       &this->overlap,
                                       &read,
-                                      false))
+                                      false) && read)
             {
                 DispatchCb(read);
-                return read;
+                return true;
             }
         }
         else

Source/IO/FS/Async.NT.hpp

@@ -51,6 +51,7 @@ namespace Aurora::IO::FS
         ~NtAsyncFileTransaction();
 
         bool Init(const AuSPtr<FileHandle> &handle);
+        void ResetAIO();
 
         bool StartRead(AuUInt64 offset, const AuSPtr<AuMemoryViewWrite> &memoryView) override;
         bool StartWrite(AuUInt64 offset, const AuSPtr<AuMemoryViewRead> &memoryView) override;

Source/IO/Net/AuNetStream.NT.cpp

@@ -300,10 +300,15 @@ namespace Aurora::IO::Net
                 return true;
             }
 
-            if (::GetOverlappedResult((HANDLE)this->GetSocket(), &this->overlap, &read, false))
+            if (!this->pMemoryHold)
+            {
+                return false;
+            }
+
+            if (::GetOverlappedResult((HANDLE)this->GetSocket(), &this->overlap, &read, false) && read)
             {
                 DispatchCb(read);
-                return read;
+                return true;
             }
         }
         else
@@ -397,7 +402,7 @@ namespace Aurora::IO::Net
     {
         if (AuExchange(this->pPin, AuSharedFromThis()))
         {
-            while (SleepEx(100, true) == WAIT_IO_COMPLETION)
+            while (SleepEx(0, true) == WAIT_IO_COMPLETION)
             {
 
             }

Source/IO/WaitMultiple.NT.cpp

@@ -52,14 +52,18 @@ namespace Aurora::IO
         {
             return {};
         }
+        
+        AuDebug::AddMemoryCrunch();
 
-        retTransasctions.reserve(transactions.size());
+        AuTryReserve(retTransasctions, transactions.size());
 
         for (const auto &file : transactions)
         {
-            AuTryInsert(handles, AuStaticPointerCast<FS::NtAsyncFileTransaction>(file)->GetHandle());
+            SysAssert(AuTryInsert(handles, AuStaticPointerCast<FS::NtAsyncFileTransaction>(file)->GetHandle()));
         }
 
+        AuDebug::DecMemoryCrunch();
+
         auto ret = WaitForMultipleObjectsEx(handles.size(), handles.data(), false, timeoutMs ? timeoutMs : INFINITE, TRUE);
 
         if (ret == WAIT_TIMEOUT || ret == WAIT_FAILED)
@@ -71,7 +75,9 @@ namespace Aurora::IO
         {
             if (AuStaticPointerCast<FS::NtAsyncFileTransaction>(file)->Complete())
             {
-                AuTryInsert(retTransasctions, file);
+                AuDebug::AddMemoryCrunch();
+                SysAssert(AuTryInsert(retTransasctions, file));
+                AuDebug::DecMemoryCrunch();
             }
         }