From 444bb36f82eb5a55ea68668166c10f65428de24b Mon Sep 17 00:00:00 2001
From: Alex Ionescu <aionescu@gmail.com>
Date: Thu, 5 Jan 2006 15:32:08 +0000
Subject: [PATCH] - Change dispatcher lock release to be more like documented
 in Windows Internals II and to allow an easier move to Queued Spinlock.

svn path=/trunk/; revision=20579
---
 reactos/ntoskrnl/include/internal/ke.h | 12 ++++++++----
 reactos/ntoskrnl/ke/wait.c             | 15 ++++-----------
 2 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/reactos/ntoskrnl/include/internal/ke.h b/reactos/ntoskrnl/include/internal/ke.h
index 30bf212a785..9c8a49ac060 100644
--- a/reactos/ntoskrnl/include/internal/ke.h
+++ b/reactos/ntoskrnl/include/internal/ke.h
@@ -51,6 +51,7 @@ extern ULONG_PTR KERNEL_BASE;
 #ifndef CONFIG_SMP
 #define KeInitializeDispatcher()
 #define KeAcquireDispatcherDatabaseLock() KeRaiseIrqlToDpcLevel();
+#define KeReleaseDispatcherDatabaseLock(OldIrql) KiExitDispatcher(OldIrql);
 #define KeAcquireDispatcherDatabaseLockAtDpcLevel()
 #define KeReleaseDispatcherDatabaseLockFromDpcLevel()
 #else
@@ -60,6 +61,9 @@ extern ULONG_PTR KERNEL_BASE;
     KeAcquireSpinLockAtDpcLevel (&DispatcherDatabaseLock);
 #define KeReleaseDispatcherDatabaseLockFromDpcLevel() \
     KeReleaseSpinLockFromDpcLevel(&DispatcherDatabaseLock);
+#define KeReleaseDispatcherDatabaseLock(OldIrql) \
+    KeReleaseSpinLockFromDpcLevel(&DispatcherDatabaseLock); \
+    KiExitDispatcher(OldIrql);
 #endif
 
 /* The following macro initializes a dispatcher object's header */
@@ -259,6 +263,10 @@ VOID
 STDCALL
 KiAdjustQuantumThread(IN PKTHREAD Thread);
 
+VOID
+FASTCALL
+KiExitDispatcher(KIRQL OldIrql);
+
 /* gmutex.c ********************************************************************/
 
 VOID
@@ -386,10 +394,6 @@ KiExpireTimers(
     PVOID SystemArgument2
 );
 
-VOID
-FASTCALL
-KeReleaseDispatcherDatabaseLock(KIRQL Irql);
-
 VOID
 STDCALL
 KeInitializeThread(
diff --git a/reactos/ntoskrnl/ke/wait.c b/reactos/ntoskrnl/ke/wait.c
index 79b18f686d7..fad80d9c993 100644
--- a/reactos/ntoskrnl/ke/wait.c
+++ b/reactos/ntoskrnl/ke/wait.c
@@ -798,7 +798,7 @@ KiAcquireFastMutex(IN PFAST_MUTEX FastMutex)
 
 VOID
 FASTCALL
-KeReleaseDispatcherDatabaseLock(KIRQL OldIrql)
+KiExitDispatcher(KIRQL OldIrql)
 {
     /* If it's the idle thread, dispatch */
     if (!(KeIsExecutingDpc()) &&
@@ -807,17 +807,10 @@ KeReleaseDispatcherDatabaseLock(KIRQL OldIrql)
         (KeGetCurrentThread() == KeGetCurrentPrcb()->IdleThread))
     {
         KiDispatchThreadNoLock(Ready);
-        KeLowerIrql(OldIrql);
-    }
-    else
-    {
-        /* Just release the spin lock */
-#ifdef CONFIG_SMP
-        KeReleaseSpinLock(&DispatcherDatabaseLock, OldIrql);
-#else
-        KeLowerIrql(OldIrql);
-#endif
     }
+
+    /* Lower irql back */
+    KeLowerIrql(OldIrql);
 }
 
 /* EOF */