1 files changed, 72 insertions, 0 deletions
diff --git a/libs/hostgraphics/ui/Fence.h b/libs/hostgraphics/ui/Fence.h
new file mode 100644
index 000000000000..04d535c3a211
--- /dev/null
+++ b/libs/hostgraphics/ui/Fence.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#ifndef ANDROID_FENCE_H
+#define ANDROID_FENCE_H
+
+#include <utils/String8.h>
+#include <utils/RefBase.h>
+
+typedef int64_t nsecs_t;
+
+namespace android {
+
+class Fence : public LightRefBase<Fence> {
+public:
+    Fence() { }
+    Fence(int) { }
+    static const sp<Fence> NO_FENCE;
+    static constexpr nsecs_t SIGNAL_TIME_PENDING = INT64_MAX;
+    static constexpr nsecs_t SIGNAL_TIME_INVALID = -1;
+    static sp<Fence> merge(const char* name, const sp<Fence>& f1, const sp<Fence>& f2) {
+        return NO_FENCE;
+    }
+
+    static sp<Fence> merge(const String8& name, const sp<Fence>& f1, const sp<Fence>& f2) {
+        return NO_FENCE;
+    }
+
+    enum class Status {
+        Invalid,     // Fence is invalid
+        Unsignaled,  // Fence is valid but has not yet signaled
+        Signaled,    // Fence is valid and has signaled
+    };
+
+    status_t wait(int timeout) { return OK; }
+
+    status_t waitForever(const char* logname) { return OK; }
+
+    int dup() const { return 0; }
+
+    inline Status getStatus() {
+        // The sync_wait call underlying wait() has been measured to be
+        // significantly faster than the sync_fence_info call underlying
+        // getSignalTime(), which might otherwise appear to be the more obvious
+        // way to check whether a fence has signaled.
+        switch (wait(0)) {
+            case NO_ERROR:
+                return Status::Signaled;
+            case -ETIME:
+                return Status::Unsignaled;
+            default:
+                return Status::Invalid;
+        }
+    }
+};
+
+} // namespace android
+
+#endif // ANDROID_FENCE_H