[Spice-devel] [PATCH 04/12] qxl-wddm-dod: Debug warning on long wait on event

[Yuri Benditovich]

In release build this does not affect the code.
In debug build we will have a warning printout when waiting
on event is close to 2 seconds - this can be a cause of following
stop by OS. The printout contains name of related event variable.
There is one event (in offload thread) that long wait on it
does not affect any functionality, for it this warning is disabled.

Signed-off-by: Yuri Benditovich <yuri.benditovich at daynix.com>
---
 qxldod/QxlDod.cpp |  3 ++-
 qxldod/QxlDod.h   | 15 +++++++++++++--
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/qxldod/QxlDod.cpp b/qxldod/QxlDod.cpp
index 01de9b3..7e3afb3 100755
--- a/qxldod/QxlDod.cpp
+++ b/qxldod/QxlDod.cpp
@@ -5095,7 +5095,8 @@ void QxlDevice::PresentThreadRoutine()
         // No need for a mutex, only one consumer thread
         SPICE_RING_CONS_WAIT(m_PresentRing, wait);
         while (wait) {
-            WaitForObject(&m_PresentEvent, NULL);
+            // we do not want indication of long wait on this event
+            DoWaitForObject(&m_PresentEvent, NULL, NULL);
             SPICE_RING_CONS_WAIT(m_PresentRing, wait);
         }
         drawables = *SPICE_RING_CONS_ITEM(m_PresentRing);
diff --git a/qxldod/QxlDod.h b/qxldod/QxlDod.h
index 324b940..7bb5de5 100755
--- a/qxldod/QxlDod.h
+++ b/qxldod/QxlDod.h
@@ -416,11 +416,13 @@ struct Resource {
 
 BOOLEAN
 FORCEINLINE
-WaitForObject(
+DoWaitForObject(
     PVOID Object,
-    PLARGE_INTEGER Timeout)
+    PLARGE_INTEGER Timeout,
+    LPCSTR name)
 {
     NTSTATUS status;
+    TimeMeasurement tm;
     status = KeWaitForSingleObject (
             Object,
             Executive,
@@ -428,9 +430,18 @@ WaitForObject(
             FALSE,
             Timeout);
     ASSERT(NT_SUCCESS(status));
+    tm.Stop();
+    if (name && tm.Diff() > 1900)
+    {
+        // 2 seconds in PresentDisplayOnly triggers watchdog on Win10RS1
+        // when VSync control enabled. Print the exact event name.
+        DbgPrint(TRACE_LEVEL_ERROR, ("Waiting %d ms for %s\n", tm.Diff(), name));
+    }
     return (status == STATUS_SUCCESS);
 }
 
+#define WaitForObject(o, timeout) DoWaitForObject((o), (timeout), #o)
+
 VOID
 FORCEINLINE
 ReleaseMutex(
-- 
2.7.0.windows.1