libgui: plumb setFrameRate thru BufferQueue

The current implementation just assumes that the Surface
and BLASTBufferQueue lives in the same process and rely
on inheritance to handle setFrameRate. This doesn't work
for any usecase that the Surface is Parceled to a diffrent process.

Bug: 281695725
Test: atest CtsGraphicsTestCases --test-filter SetFrameRateTest*
Change-Id: I4e08b92b618fa7b863ca3ef4f7b46d9f1c30c775

1 files changed, 65 insertions, 0 deletions

diff --git a/libs/gui/FrameRateUtils.cpp b/libs/gui/FrameRateUtils.cpp
new file mode 100644
index 0000000000..6993bfab45
--- /dev/null
+++ b/libs/gui/FrameRateUtils.cpp
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gui/Flags.h>
+#include <gui/FrameRateUtils.h>
+#include <system/window.h>
+#include <utils/Log.h>
+
+#include <cmath>
+
+namespace android {
+// Returns true if the frameRate is valid.
+//
+// @param frameRate the frame rate in Hz
+// @param compatibility a ANATIVEWINDOW_FRAME_RATE_COMPATIBILITY_*
+// @param changeFrameRateStrategy a ANATIVEWINDOW_CHANGE_FRAME_RATE_*
+// @param functionName calling function or nullptr. Used for logging
+// @param privileged whether caller has unscoped surfaceflinger access
+bool ValidateFrameRate(float frameRate, int8_t compatibility, int8_t changeFrameRateStrategy,
+                       const char* inFunctionName, bool privileged) {
+    const char* functionName = inFunctionName != nullptr ? inFunctionName : "call";
+    int floatClassification = std::fpclassify(frameRate);
+    if (frameRate < 0 || floatClassification == FP_INFINITE || floatClassification == FP_NAN) {
+        ALOGE("%s failed - invalid frame rate %f", functionName, frameRate);
+        return false;
+    }
+
+    if (compatibility != ANATIVEWINDOW_FRAME_RATE_COMPATIBILITY_DEFAULT &&
+        compatibility != ANATIVEWINDOW_FRAME_RATE_COMPATIBILITY_FIXED_SOURCE &&
+        (!privileged ||
+         (compatibility != ANATIVEWINDOW_FRAME_RATE_EXACT &&
+          compatibility != ANATIVEWINDOW_FRAME_RATE_NO_VOTE))) {
+        ALOGE("%s failed - invalid compatibility value %d privileged: %s", functionName,
+              compatibility, privileged ? "yes" : "no");
+        return false;
+    }
+
+    if (__builtin_available(android 31, *)) {
+        if (changeFrameRateStrategy != ANATIVEWINDOW_CHANGE_FRAME_RATE_ONLY_IF_SEAMLESS &&
+            changeFrameRateStrategy != ANATIVEWINDOW_CHANGE_FRAME_RATE_ALWAYS) {
+            ALOGE("%s failed - invalid change frame rate strategy value %d", functionName,
+                  changeFrameRateStrategy);
+            if (FLAG_BQ_SET_FRAME_RATE) {
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
+} // namespace android