From 1fca2400a4bdb7a40663ad3369146520fcb903c7 Mon Sep 17 00:00:00 2001
From: Aiken Harris <harraiken91@gmail.com>
Date: Wed, 17 Jun 2026 16:30:28 +0200
Subject: [PATCH] Add functions to transition threads to deferred ready or
 transition states

---
 xtoskrnl/includes/ke/kthread.hh |  2 ++
 xtoskrnl/ke/kthread.cc          | 60 +++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/xtoskrnl/includes/ke/kthread.hh b/xtoskrnl/includes/ke/kthread.hh
index 4f724a4..241d384 100644
--- a/xtoskrnl/includes/ke/kthread.hh
+++ b/xtoskrnl/includes/ke/kthread.hh
@@ -22,6 +22,7 @@ namespace KE
 
         public:
             STATIC XTAPI VOID AttachThread(IN PKTHREAD Thread);
+            STATIC XTAPI VOID DispatchReadyThread(IN PKTHREAD Thread);
             STATIC XTAPI PETHREAD GetInitialThread(VOID);
             STATIC XTAPI XTSTATUS InitializeIdleThread(IN PKPROCESS IdleProcess,
                                                        IN OUT PKTHREAD IdleThread,
@@ -36,6 +37,7 @@ namespace KE
                                                    IN PVOID EnvironmentBlock,
                                                    IN PVOID Stack,
                                                    IN BOOLEAN AttachToProcess);
+            STATIC XTAPI VOID ReadyThread(IN PKTHREAD Thread);
 
         private:
             STATIC XTAPI VOID HandleSystemThreadExit(VOID);
diff --git a/xtoskrnl/ke/kthread.cc b/xtoskrnl/ke/kthread.cc
index 69565f4..7cc6182 100644
--- a/xtoskrnl/ke/kthread.cc
+++ b/xtoskrnl/ke/kthread.cc
@@ -75,6 +75,44 @@ KE::KThread::AttachThread(IN OUT PKTHREAD Thread)
     }
 }
 
+/**
+ * Transitions a thread to the ready state and queues it for execution within the dispatcher database.
+ *
+ * @param Thread
+ *        Supplies a pointer to the thread to be dispatched.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+VOID
+KE::KThread::DispatchReadyThread(IN PKTHREAD Thread)
+{
+    PKPROCESS Process;
+
+    /* Extract the process from the thread's APC state */
+    Process = Thread->ApcState.Process;
+
+    /* Verify if the process and thread are resident in physical memory */
+    if(Process->State != ProcessInMemory)
+    {
+        /* Process is swapped out, place the thread in a transition state */
+        Thread->State = Transition;
+    }
+    else if(!Thread->KernelStackResident)
+    {
+        /* Increment the active stack count and transition the thread */
+        Process->StackCount++;
+        Thread->State = Transition;
+    }
+    else
+    {
+        /* Both process and thread's stack are fully resident, queue the thread for execution */
+        KE::Scheduler::InsertDeferredReadyList(Thread);
+    }
+}
+
 /**
  * Retrieves a pointer to the system's initial executive thread object.
  *
@@ -346,6 +384,28 @@ KE::KThread::InitializeThread(IN PKPROCESS Process,
     return STATUS_SUCCESS;
 }
 
+/**
+ * Prepares a thread for execution by safely acquiring the dispatcher database lock.
+ *
+ * @param Thread
+ *        Supplies a pointer to the thread to be readied.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+VOID
+KE::KThread::ReadyThread(IN PKTHREAD Thread)
+{
+    /* Raise runlevel to SYNC level and acquire the dispatcher database lock */
+    KE::RaiseRunLevel RunLevel(SYNC_LEVEL);
+    KE::QueuedSpinLockGuard DispatcherGuard(DispatcherLock);
+
+    /* Evaluate residency and queue the thread */
+    DispatchReadyThread(Thread);
+}
+
 /**
  * Suspend APC-built thread NOP routine. It takes no actions.
  *