diff --git a/libs/binder/FdTrigger.h b/libs/binder/FdTrigger.h
new file mode 100644
index 0000000..984e685
--- /dev/null
+++ b/libs/binder/FdTrigger.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2021 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 <memory>
+
+#include <android-base/unique_fd.h>
+#include <utils/Errors.h>
+
+namespace android {
+
+/** This is not a pipe. */
+class FdTrigger {
+public:
+    /** Returns nullptr for error case */
+    static std::unique_ptr<FdTrigger> make();
+
+    /**
+     * Close the write end of the pipe so that the read end receives POLLHUP.
+     * Not threadsafe.
+     */
+    void trigger();
+
+    /**
+     * Whether this has been triggered.
+     */
+    bool isTriggered();
+
+    /**
+     * Poll for a read event.
+     *
+     * event - for pollfd
+     *
+     * Return:
+     *   true - time to read!
+     *   false - trigger happened
+     */
+    status_t triggerablePoll(base::borrowed_fd fd, int16_t event);
+
+private:
+    base::unique_fd mWrite;
+    base::unique_fd mRead;
+};
+} // namespace android