[PATCH 2/5] wined3d: Block in wined3d_cs_emit_present() when we reach the latency limit.

[Matteo Bruni]

From: Matteo Bruni

Avoid busy spinning for a potentially long time.
---
 dlls/wined3d/cs.c              | 25 ++++++++++++++++++++++++-
 dlls/wined3d/wined3d_private.h |  3 ++-
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/dlls/wined3d/cs.c b/dlls/wined3d/cs.c
index 6a09ec2a35a..14f2ca9bb4a 100644
--- a/dlls/wined3d/cs.c
+++ b/dlls/wined3d/cs.c
@@ -724,6 +724,8 @@ static void wined3d_cs_exec_present(struct wined3d_cs *cs, const void *data)
     }

InterlockedDecrement(&cs->pending_presents);
+    if (InterlockedCompareExchange(&cs->waiting_for_present, FALSE, TRUE))
+        SetEvent(cs->present_event);
 }

void wined3d_cs_emit_present(struct wined3d_cs *cs, struct wined3d_swapchain *swapchain,
@@ -734,6 +736,8 @@ void wined3d_cs_emit_present(struct wined3d_cs *cs, struct wined3d_swapchain *sw
     unsigned int i;
     LONG pending;

+    wined3d_not_from_cs(cs);
+
     op = wined3d_device_context_require_space(&cs->c, sizeof(*op), WINED3D_CS_QUEUE_DEFAULT);
     op->opcode = WINED3D_CS_OP_PRESENT;
     op->dst_window_override = dst_window_override;
@@ -757,8 +761,17 @@ void wined3d_cs_emit_present(struct wined3d_cs *cs, struct wined3d_swapchain *sw
      * ahead of the worker thread. */
     while (pending >= swapchain->max_frame_latency)
     {
-        YieldProcessor();
+        InterlockedExchange(&cs->waiting_for_present, TRUE);
+
         pending = InterlockedCompareExchange(&cs->pending_presents, 0, 0);
+        if (pending >= swapchain->max_frame_latency || !InterlockedCompareExchange(&cs->waiting_for_present, FALSE, TRUE))
+        {
+            TRACE_(d3d_perf)("Reached latency limit (%u frames), blocking to wait.\n", swapchain->max_frame_latency);
+            wined3d_mutex_unlock();
+            WaitForSingleObject(cs->present_event, INFINITE);
+            wined3d_mutex_lock();
+            TRACE_(d3d_perf)("Woken up from the wait.\n");
+        }
     }
 }

@@ -3472,11 +3485,18 @@ struct wined3d_cs *wined3d_cs_create(struct wined3d_device *device,
             heap_free(cs->data);
             goto fail;
         }
+        if (!(cs->present_event = CreateEventW(NULL, FALSE, FALSE, NULL)))
+        {
+            ERR("Failed to create command stream present event.\n");
+            heap_free(cs->data);
+            goto fail;
+        }

if (!(GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
                 (const WCHAR *)wined3d_cs_run, &cs->wined3d_module)))
         {
             ERR("Failed to get wined3d module handle.\n");
+            CloseHandle(cs->present_event);
             CloseHandle(cs->event);
             heap_free(cs->data);
             goto fail;
@@ -3486,6 +3506,7 @@ struct wined3d_cs *wined3d_cs_create(struct wined3d_device *device,
         {
             ERR("Failed to create wined3d command stream thread.\n");
             FreeLibrary(cs->wined3d_module);
+            CloseHandle(cs->present_event);
             CloseHandle(cs->event);
             heap_free(cs->data);
             goto fail;
@@ -3508,6 +3529,8 @@ void wined3d_cs_destroy(struct wined3d_cs *cs)
     {
         wined3d_cs_emit_stop(cs);
         CloseHandle(cs->thread);
+        if (!CloseHandle(cs->present_event))
+            ERR("Closing present event failed.\n");
         if (!CloseHandle(cs->event))
             ERR("Closing event failed.\n");
     }
diff --git a/dlls/wined3d/wined3d_private.h b/dlls/wined3d/wined3d_private.h
index be576fcfbde..c71ac59270b 100644
--- a/dlls/wined3d/wined3d_private.h
+++ b/dlls/wined3d/wined3d_private.h
@@ -5131,8 +5131,9 @@ struct wined3d_cs
     struct list query_poll_list;
     BOOL queries_flushed;

-    HANDLE event;
+    HANDLE event, present_event;
     LONG waiting_for_event;
+    LONG waiting_for_present;
     LONG pending_presents;
 };