diff --git a/libs/ui/Android.bp b/libs/ui/Android.bp
index f770975..a4d0dd1 100644
--- a/libs/ui/Android.bp
+++ b/libs/ui/Android.bp
@@ -55,6 +55,7 @@
     srcs: [
         "ColorSpace.cpp",
         "BufferHubBuffer.cpp",
+        "BufferHubEventFd.cpp",
         "BufferHubMetadata.cpp",
         "DebugUtils.cpp",
         "Fence.cpp",
@@ -112,6 +113,7 @@
             cflags: ["-DLIBUI_IN_VNDK"],
             exclude_srcs: [
                 "BufferHubBuffer.cpp",
+                "BufferHubEventFd.cpp",
                 "BufferHubMetadata.cpp",
             ],
             exclude_header_libs: [
diff --git a/libs/ui/BufferHubEventFd.cpp b/libs/ui/BufferHubEventFd.cpp
new file mode 100644
index 0000000..978b352
--- /dev/null
+++ b/libs/ui/BufferHubEventFd.cpp
@@ -0,0 +1,47 @@
+/*
+ * 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)) {}
+
+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
diff --git a/libs/ui/include/ui/BufferHubEventFd.h b/libs/ui/include/ui/BufferHubEventFd.h
new file mode 100644
index 0000000..0e856bd
--- /dev/null
+++ b/libs/ui/include/ui/BufferHubEventFd.h
@@ -0,0 +1,59 @@
+/*
+ * 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.
+ */
+
+#ifndef ANDROID_BUFFER_HUB_EVENT_FD_H_
+#define ANDROID_BUFFER_HUB_EVENT_FD_H_
+
+#include <android-base/unique_fd.h>
+#include <utils/Errors.h>
+
+namespace android {
+
+class BufferHubEventFd {
+public:
+    /**
+     * Constructs a valid event fd.
+     */
+    BufferHubEventFd();
+
+    /**
+     * Returns whether this BufferHubEventFd holds a valid event_fd.
+     */
+    bool isValid() const { return get() >= 0; }
+
+    /**
+     * Returns the fd number of the BufferHubEventFd object. Note that there is no ownership
+     * transfer.
+     */
+    int get() const { return mFd.get(); }
+
+    /**
+     * Signals the eventfd.
+     */
+    status_t signal() const;
+
+    /**
+     * Clears the signal from this eventfd if it is signaled.
+     */
+    status_t clear() const;
+
+private:
+    base::unique_fd mFd;
+};
+
+} // namespace android
+
+#endif // ANDROID_BUFFER_HUB_EVENT_FD_H_
diff --git a/libs/ui/tests/Android.bp b/libs/ui/tests/Android.bp
index b7ad4e5..988103d 100644
--- a/libs/ui/tests/Android.bp
+++ b/libs/ui/tests/Android.bp
@@ -51,15 +51,22 @@
         "libdvr_headers",
         "libnativewindow_headers",
     ],
+    static_libs: [
+        "libgmock",
+    ],
     shared_libs: [
         "android.frameworks.bufferhub@1.0",
         "libhidlbase",
         "libhwbinder",
+        "liblog",
         "libpdx_default_transport",
         "libui",
         "libutils"
     ],
-    srcs: ["BufferHubBuffer_test.cpp"],
+    srcs: [
+        "BufferHubBuffer_test.cpp",
+        "BufferHubEventFd_test.cpp",
+    ],
     cflags: ["-Wall", "-Werror"],
 }
 
diff --git a/libs/ui/tests/BufferHubEventFd_test.cpp b/libs/ui/tests/BufferHubEventFd_test.cpp
new file mode 100644
index 0000000..8e61c68
--- /dev/null
+++ b/libs/ui/tests/BufferHubEventFd_test.cpp
@@ -0,0 +1,338 @@
+/*
+ * Copyright 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.
+ */
+
+#define LOG_TAG "BufferHubEventFdTest"
+
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+
+#include <hidl/ServiceManagement.h>
+#include <hwbinder/IPCThreadState.h>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <ui/BufferHubEventFd.h>
+
+namespace android {
+
+namespace {
+
+const int kTimeout = 100;
+const std::chrono::milliseconds kTimeoutMs(kTimeout);
+
+using ::testing::Contains;
+using BufferHubEventFdTest = ::testing::Test;
+
+} // namespace
+
+TEST_F(BufferHubEventFdTest, EventFd_testSingleEpollFd) {
+    BufferHubEventFd eventFd;
+    ASSERT_TRUE(eventFd.isValid());
+
+    base::unique_fd epollFd(epoll_create(64));
+    epoll_event e = {.events = EPOLLIN | EPOLLET, .data = {.u32 = 0}};
+
+    ASSERT_GE(epollFd.get(), 0);
+    ASSERT_EQ(epoll_ctl(epollFd.get(), EPOLL_CTL_ADD, eventFd.get(), &e), 0);
+
+    std::array<epoll_event, 1> events;
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
+
+    eventFd.signal();
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 1);
+
+    // The epoll fd is edge triggered, so it only responds to the eventFd once.
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
+}
+
+TEST_F(BufferHubEventFdTest, EventFd_testClear) {
+    BufferHubEventFd eventFd;
+    ASSERT_TRUE(eventFd.isValid());
+
+    base::unique_fd epollFd(epoll_create(64));
+    epoll_event e = {.events = EPOLLIN | EPOLLET, .data = {.u32 = 0}};
+
+    ASSERT_GE(epollFd.get(), 0);
+    ASSERT_EQ(epoll_ctl(epollFd.get(), EPOLL_CTL_ADD, eventFd.get(), &e), 0);
+
+    eventFd.signal();
+    eventFd.clear();
+
+    std::array<epoll_event, 1> events;
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
+}
+
+TEST_F(BufferHubEventFdTest, EventFd_testDupEventFd) {
+    BufferHubEventFd eventFd;
+    ASSERT_TRUE(eventFd.isValid());
+
+    base::unique_fd epollFd(epoll_create(64));
+    epoll_event e = {.events = EPOLLIN | EPOLLET, .data = {.u32 = 0}};
+
+    ASSERT_GE(epollFd.get(), 0);
+    ASSERT_EQ(epoll_ctl(epollFd.get(), EPOLL_CTL_ADD, eventFd.get(), &e), 0);
+
+    // Technically, the dupliated eventFd and the original eventFd are pointing
+    // to the same kernel object. This test signals the duplicated eventFd but epolls the origianl
+    // eventFd.
+    base::unique_fd dupedEventFd(dup(eventFd.get()));
+    ASSERT_GE(dupedEventFd.get(), 0);
+
+    std::array<epoll_event, 1> events;
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
+
+    eventfd_write(dupedEventFd.get(), 1);
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 1);
+
+    // The epoll fd is edge triggered, so it only responds to the eventFd once.
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
+
+    eventfd_write(dupedEventFd.get(), 1);
+
+    eventfd_t value;
+    eventfd_read(dupedEventFd.get(), &value);
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
+}
+
+TEST_F(BufferHubEventFdTest, EventFd_testTwoEpollFds) {
+    BufferHubEventFd eventFd;
+    ASSERT_TRUE(eventFd.isValid());
+
+    base::unique_fd epollFd1(epoll_create(64));
+    base::unique_fd epollFd2(epoll_create(64));
+    epoll_event e = {.events = EPOLLIN | EPOLLET, .data = {.u32 = 0}};
+
+    ASSERT_GE(epollFd1.get(), 0);
+    ASSERT_GE(epollFd2.get(), 0);
+
+    // Register the same eventFd to two EpollFds.
+    ASSERT_EQ(epoll_ctl(epollFd1.get(), EPOLL_CTL_ADD, eventFd.get(), &e), 0);
+    ASSERT_EQ(epoll_ctl(epollFd2.get(), EPOLL_CTL_ADD, eventFd.get(), &e), 0);
+
+    std::array<epoll_event, 1> events;
+    EXPECT_EQ(epoll_wait(epollFd1.get(), events.data(), events.size(), 0), 0);
+    EXPECT_EQ(epoll_wait(epollFd2.get(), events.data(), events.size(), 0), 0);
+
+    eventFd.signal();
+    EXPECT_EQ(epoll_wait(epollFd1.get(), events.data(), events.size(), 0), 1);
+    EXPECT_EQ(epoll_wait(epollFd2.get(), events.data(), events.size(), 0), 1);
+
+    // The epoll fd is edge triggered, so it only responds to the eventFd once.
+    EXPECT_EQ(epoll_wait(epollFd1.get(), events.data(), events.size(), 0), 0);
+    EXPECT_EQ(epoll_wait(epollFd2.get(), events.data(), events.size(), 0), 0);
+
+    eventFd.signal();
+    EXPECT_EQ(epoll_wait(epollFd1.get(), events.data(), events.size(), 0), 1);
+
+    eventFd.clear();
+    EXPECT_EQ(epoll_wait(epollFd1.get(), events.data(), events.size(), 0), 0);
+    EXPECT_EQ(epoll_wait(epollFd2.get(), events.data(), events.size(), 0), 0);
+}
+
+TEST_F(BufferHubEventFdTest, EventFd_testTwoEventFds) {
+    BufferHubEventFd eventFd1;
+    BufferHubEventFd eventFd2;
+
+    ASSERT_TRUE(eventFd1.isValid());
+    ASSERT_TRUE(eventFd2.isValid());
+
+    base::unique_fd epollFd(epoll_create(64));
+    epoll_event e1 = {.events = EPOLLIN | EPOLLET, .data = {.u32 = 1}};
+    epoll_event e2 = {.events = EPOLLIN | EPOLLET, .data = {.u32 = 2}};
+
+    ASSERT_GE(epollFd.get(), 0);
+    ASSERT_EQ(epoll_ctl(epollFd.get(), EPOLL_CTL_ADD, eventFd1.get(), &e1), 0);
+    ASSERT_EQ(epoll_ctl(epollFd.get(), EPOLL_CTL_ADD, eventFd2.get(), &e2), 0);
+
+    std::array<epoll_event, 2> events;
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
+
+    // Signal one by one.
+    eventFd1.signal();
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 1);
+    EXPECT_EQ(events[0].data.u32, e1.data.u32);
+
+    eventFd2.signal();
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 1);
+    EXPECT_EQ(events[0].data.u32, e2.data.u32);
+
+    // Signal both.
+    eventFd1.signal();
+    eventFd2.signal();
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 2);
+
+    uint32_t u32s[] = {events[0].data.u32, events[1].data.u32};
+    EXPECT_THAT(u32s, Contains(e1.data.u32));
+    EXPECT_THAT(u32s, Contains(e2.data.u32));
+
+    // The epoll fd is edge triggered, so it only responds to the eventFd once.
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
+
+    eventFd1.signal();
+    eventFd2.signal();
+    eventFd2.clear();
+    EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 1);
+}
+
+TEST_F(BufferHubEventFdTest, EventFd_testPollingThreadWithTwoEventFds) {
+    BufferHubEventFd eventFd1;
+    BufferHubEventFd eventFd2;
+
+    ASSERT_TRUE(eventFd1.isValid());
+    ASSERT_TRUE(eventFd2.isValid());
+
+    base::unique_fd epollFd(epoll_create(64));
+    epoll_event e1 = {.events = EPOLLIN | EPOLLET, .data = {.u32 = 1}};
+    epoll_event e2 = {.events = EPOLLIN | EPOLLET, .data = {.u32 = 2}};
+
+    ASSERT_GE(epollFd.get(), 0);
+    ASSERT_EQ(epoll_ctl(epollFd.get(), EPOLL_CTL_ADD, eventFd1.get(), &e1), 0);
+    ASSERT_EQ(epoll_ctl(epollFd.get(), EPOLL_CTL_ADD, eventFd2.get(), &e2), 0);
+
+    int countEvent1 = 0;
+    int countEvent2 = 0;
+    std::atomic<bool> stop{false};
+    std::mutex mx;
+    std::condition_variable cv;
+
+    std::thread pollingThread([&] {
+        std::array<epoll_event, 2> events;
+        while (true) {
+            if (stop.load()) {
+                break;
+            }
+            int ret = epoll_wait(epollFd.get(), events.data(), events.size(), kTimeout);
+            ALOGE_IF(ret < 0 && errno != ETIMEDOUT, "Epoll failed.");
+
+            std::lock_guard<std::mutex> lock(mx);
+            for (int i = 0; i < ret; i++) {
+                if (events[i].data.u32 == e1.data.u32) {
+                    countEvent1++;
+                    cv.notify_one();
+                } else if (events[i].data.u32 == e2.data.u32) {
+                    countEvent2++;
+                    cv.notify_one();
+                }
+            }
+        }
+    });
+
+    {
+        std::unique_lock<std::mutex> lock(mx);
+
+        eventFd1.signal();
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEvent1 == 1; }));
+
+        eventFd1.signal();
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEvent1 == 2; }));
+
+        eventFd2.signal();
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEvent2 == 1; }));
+
+        eventFd1.clear();
+        eventFd2.clear();
+        EXPECT_EQ(countEvent1, 2);
+        EXPECT_EQ(countEvent2, 1);
+
+        eventFd1.signal();
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEvent1 == 3; }));
+
+        eventFd2.signal();
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEvent2 == 2; }));
+    }
+
+    stop.store(true);
+    pollingThread.join();
+}
+
+TEST_F(BufferHubEventFdTest, EventFd_testTwoPollingThreads) {
+    BufferHubEventFd eventFd;
+    ASSERT_TRUE(eventFd.isValid());
+
+    base::unique_fd epollFd1(epoll_create(64));
+    base::unique_fd epollFd2(epoll_create(64));
+    epoll_event e = {.events = EPOLLIN | EPOLLET, .data = {.u32 = 0}};
+
+    ASSERT_GE(epollFd1.get(), 0);
+    ASSERT_GE(epollFd2.get(), 0);
+
+    // Register the same eventFd to two EpollFds.
+    ASSERT_EQ(epoll_ctl(epollFd1.get(), EPOLL_CTL_ADD, eventFd.get(), &e), 0);
+    ASSERT_EQ(epoll_ctl(epollFd2.get(), EPOLL_CTL_ADD, eventFd.get(), &e), 0);
+
+    int countEpoll1 = 0;
+    int countEpoll2 = 0;
+    std::atomic<bool> stop{false};
+    std::mutex mx;
+    std::condition_variable cv;
+
+    std::thread pollingThread1([&] {
+        std::array<epoll_event, 1> events;
+        while (!stop.load()) {
+            int ret = epoll_wait(epollFd1.get(), events.data(), events.size(), kTimeout);
+            ALOGE_IF(ret < 0 && errno != ETIMEDOUT, "Epoll failed.");
+
+            if (ret > 0) {
+                std::lock_guard<std::mutex> lock(mx);
+                countEpoll1++;
+                cv.notify_one();
+            }
+        }
+    });
+
+    std::thread pollingThread2([&] {
+        std::array<epoll_event, 1> events;
+        while (!stop.load()) {
+            int ret = epoll_wait(epollFd2.get(), events.data(), events.size(), kTimeout);
+            ALOGE_IF(ret < 0 && errno != ETIMEDOUT, "Epoll failed.");
+
+            if (ret > 0) {
+                std::lock_guard<std::mutex> lock(mx);
+                countEpoll2++;
+                cv.notify_one();
+            }
+        }
+    });
+
+    {
+        std::unique_lock<std::mutex> lock(mx);
+
+        eventFd.signal();
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEpoll1 == 1; }));
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEpoll2 == 1; }));
+
+        eventFd.signal();
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEpoll1 == 2; }));
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEpoll2 == 2; }));
+
+        eventFd.clear();
+        EXPECT_EQ(countEpoll1, 2);
+        EXPECT_EQ(countEpoll2, 2);
+
+        eventFd.signal();
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEpoll1 == 3; }));
+        EXPECT_TRUE(cv.wait_for(lock, kTimeoutMs, [&] { return countEpoll2 == 3; }));
+    }
+
+    stop.store(true);
+    pollingThread1.join();
+    pollingThread2.join();
+}
+
+} // namespace android