1 files changed, 49 insertions, 0 deletions
diff --git a/libs/ui/BufferHubEventFd.cpp b/libs/ui/BufferHubEventFd.cpp
new file mode 100644
index 0000000000..bffc2ca803
--- /dev/null
+++ b/libs/ui/BufferHubEventFd.cpp
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2018 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 <sys/eventfd.h>
+
+#include <log/log.h>
+#include <ui/BufferHubEventFd.h>
+
+namespace android {
+
+BufferHubEventFd::BufferHubEventFd() : mFd(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK)) {}
+
+BufferHubEventFd::BufferHubEventFd(int fd) : mFd(fd) {}
+
+status_t BufferHubEventFd::signal() const {
+    if (!isValid()) {
+        ALOGE("%s: cannot signal an invalid eventfd.", __FUNCTION__);
+        return DEAD_OBJECT;
+    }
+
+    eventfd_write(mFd.get(), 1);
+    return OK;
+}
+
+status_t BufferHubEventFd::clear() const {
+    if (!isValid()) {
+        ALOGE("%s: cannot clear an invalid eventfd.", __FUNCTION__);
+        return DEAD_OBJECT;
+    }
+
+    eventfd_t value;
+    eventfd_read(mFd.get(), &value);
+    return OK;
+}
+
+} // namespace android