[fireball] 59785: [NTOS] - Aleksandar Andrejevic: Implement NtQueryTimerResolution(). CORE-7387

Author: fireball
Date: Mon Aug 19 19:40:25 2013
New Revision: 59785

URL: http://svn.reactos.org/svn/reactos?rev=59785&view=rev
Log:
[NTOS]
- Aleksandar Andrejevic: Implement NtQueryTimerResolution().

CORE-7387

Modified:
    trunk/reactos/ntoskrnl/ke/clock.c

Modified: trunk/reactos/ntoskrnl/ke/clock.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ke/clock.c?rev=59…
==============================================================================
--- trunk/reactos/ntoskrnl/ke/clock.c	[iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/ke/clock.c	[iso-8859-1] Mon Aug 19 19:40:25 2013
@@ -242,8 +242,40 @@
                        OUT PULONG MaximumResolution,
                        OUT PULONG ActualResolution)
 {
-    UNIMPLEMENTED;
-    return STATUS_NOT_IMPLEMENTED;
+    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
+
+    /* Check if the call came from user mode */
+    if (PreviousMode != KernelMode)
+    {
+        _SEH2_TRY
+        {
+            /* Probe the parameters */
+            ProbeForWriteUlong(MinimumResolution);
+            ProbeForWriteUlong(MaximumResolution);
+            ProbeForWriteUlong(ActualResolution);
+
+            /* Try to set the parameters to the actual values */
+            *MinimumResolution = KeMinimumIncrement;
+            *MaximumResolution = KeMaximumIncrement;
+            *ActualResolution = KeTimeIncrement;
+        }
+        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+        {
+            /* Return the exception code */
+            _SEH2_YIELD(return _SEH2_GetExceptionCode());
+        }
+        _SEH2_END;
+    }
+    else
+    {
+        /* The call came from kernel mode. Use the pointers directly */
+        *MinimumResolution = KeMinimumIncrement;
+        *MaximumResolution = KeMaximumIncrement;
+        *ActualResolution = KeTimeIncrement;
+    }
+
+    /* Return success */
+    return STATUS_SUCCESS;
 }
 
 NTSTATUS