[PATCH v2 3/5] ntoskrnl.exe: Implement KeReadStateEvent.

[Derek Lesho]

Signed-off-by: Derek Lesho 
---
v2:
  - Added tests.
  - Added header definition.
---
 dlls/ntoskrnl.exe/ntoskrnl.exe.spec |  2 +-
 dlls/ntoskrnl.exe/sync.c            | 22 ++++++++++++++++++++++
 dlls/ntoskrnl.exe/tests/driver.c    | 11 +++++++++++
 include/ddk/wdm.h                   |  1 +
 4 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
index 34fde20f8a4..b2d7d8b9640 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
+++ b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
@@ -599,7 +599,7 @@
 @ stdcall KeQueryTickCount(ptr)
 @ stdcall KeQueryTimeIncrement()
 @ stub KeRaiseUserException
-@ stub KeReadStateEvent
+@ stdcall KeReadStateEvent(ptr)
 @ stub KeReadStateMutant
 @ stub KeReadStateMutex
 @ stub KeReadStateQueue
diff --git a/dlls/ntoskrnl.exe/sync.c b/dlls/ntoskrnl.exe/sync.c
index 5e06ab2f2b6..7f19ce7571b 100644
--- a/dlls/ntoskrnl.exe/sync.c
+++ b/dlls/ntoskrnl.exe/sync.c
@@ -311,6 +311,28 @@ void WINAPI KeClearEvent( PRKEVENT event )
     KeResetEvent( event );
 }

+/***********************************************************************
+ *           KeReadStateEvent (NTOSKRNL.EXE.@)
+ */
+LONG WINAPI KeReadStateEvent( PRKEVENT event )
+{
+    HANDLE handle;
+
+    TRACE("event %p.\n", event);
+
+    if (event->Header.WaitListHead.Blink == INVALID_HANDLE_VALUE)
+    {
+        if (!(ObOpenObjectByPointer( event, OBJ_KERNEL_HANDLE, NULL, EVENT_QUERY_STATE, NULL, KernelMode, &handle )))
+        {
+            EVENT_BASIC_INFORMATION event_info;
+            if (!(NtQueryEvent( handle, EventBasicInformation, &event_info, sizeof(event_info), NULL)))
+                event->Header.SignalState = event_info.EventState;
+            NtClose( handle );
+        }
+    }
+    return event->Header.SignalState;
+}
+
 /***********************************************************************
  *           KeInitializeSemaphore   (NTOSKRNL.EXE.@)
  */
diff --git a/dlls/ntoskrnl.exe/tests/driver.c b/dlls/ntoskrnl.exe/tests/driver.c
index bb5bbeb4fa5..d1503f824ef 100644
--- a/dlls/ntoskrnl.exe/tests/driver.c
+++ b/dlls/ntoskrnl.exe/tests/driver.c
@@ -447,8 +447,14 @@ static void test_sync(void)
     ret = wait_single(&manual_event, 0);
     ok(ret == STATUS_TIMEOUT, "got %#x\n", ret);

+    ret = KeReadStateEvent(&manual_event);
+    ok(ret == 0, "got %d\n", ret);
+
     KeSetEvent(&manual_event, 0, FALSE);

+    ret = KeReadStateEvent(&manual_event);
+    ok(ret == 1, "got %d\n", ret);
+
     ret = wait_single(&manual_event, 0);
     ok(ret == 0, "got %#x\n", ret);

@@ -541,9 +547,14 @@ static void test_sync(void)
     ret = ObReferenceObjectByHandle(handle, SYNCHRONIZE, *pExEventObjectType, KernelMode, (void **)&event, NULL);
     ok(!ret, "ObReferenceObjectByHandle failed: %#x\n", ret);

+
     ret = wait_single(event, 0);
     ok(ret == 0, "got %#x\n", ret);
+    ret = KeReadStateEvent(event);
+    ok(ret == 1, "got %d\n", ret);
     KeResetEvent(event);
+    ret = KeReadStateEvent(event);
+    ok(ret == 0, "got %d\n", ret);
     ret = wait_single(event, 0);
     ok(ret == STATUS_TIMEOUT, "got %#x\n", ret);
     ret = wait_single_handle(handle, 0);
diff --git a/include/ddk/wdm.h b/include/ddk/wdm.h
index 59af860708b..176b432644a 100644
--- a/include/ddk/wdm.h
+++ b/include/ddk/wdm.h
@@ -1759,6 +1759,7 @@ KAFFINITY WINAPI KeQueryActiveProcessors(void);
 void      WINAPI KeQuerySystemTime(LARGE_INTEGER*);
 void      WINAPI KeQueryTickCount(LARGE_INTEGER*);
 ULONG     WINAPI KeQueryTimeIncrement(void);
+LONG      WINAPI KeReadStateEvent(PRKEVENT);
 void    FASTCALL KeReleaseInStackQueuedSpinLockFromDpcLevel(KLOCK_QUEUE_HANDLE*);
 LONG      WINAPI KeReleaseMutex(PRKMUTEX,BOOLEAN);
 LONG      WINAPI KeReleaseSemaphore(PRKSEMAPHORE,KPRIORITY,LONG,BOOLEAN);