diff --git a/media/utils/TimerThread-test.cpp b/media/utils/TimerThread-test.cpp
new file mode 100644
index 0000000..ee8a811
--- /dev/null
+++ b/media/utils/TimerThread-test.cpp
@@ -0,0 +1,146 @@
+/*
+ * 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 <chrono>
+#include <thread>
+#include <gtest/gtest.h>
+#include <mediautils/TimerThread.h>
+
+using namespace std::chrono_literals;
+
+namespace android {
+namespace {
+
+constexpr auto kJitter = 10ms;
+
+TEST(TimerThread, Basic) {
+    std::atomic<bool> taskRan = false;
+    TimerThread thread;
+    thread.scheduleTask([&taskRan] { taskRan = true; }, 100ms);
+    std::this_thread::sleep_for(100ms - kJitter);
+    ASSERT_FALSE(taskRan);
+    std::this_thread::sleep_for(2 * kJitter);
+    ASSERT_TRUE(taskRan);
+}
+
+TEST(TimerThread, Cancel) {
+    std::atomic<bool> taskRan = false;
+    TimerThread thread;
+    TimerThread::Handle handle = thread.scheduleTask([&taskRan] { taskRan = true; }, 100ms);
+    std::this_thread::sleep_for(100ms - kJitter);
+    ASSERT_FALSE(taskRan);
+    thread.cancelTask(handle);
+    std::this_thread::sleep_for(2 * kJitter);
+    ASSERT_FALSE(taskRan);
+}
+
+TEST(TimerThread, CancelAfterRun) {
+    std::atomic<bool> taskRan = false;
+    TimerThread thread;
+    TimerThread::Handle handle = thread.scheduleTask([&taskRan] { taskRan = true; }, 100ms);
+    std::this_thread::sleep_for(100ms + kJitter);
+    ASSERT_TRUE(taskRan);
+    thread.cancelTask(handle);
+}
+
+TEST(TimerThread, MultipleTasks) {
+    std::array<std::atomic<bool>, 6> taskRan;
+    TimerThread thread;
+
+    auto startTime = std::chrono::steady_clock::now();
+
+    thread.scheduleTask([&taskRan] { taskRan[0] = true; }, 300ms);
+    thread.scheduleTask([&taskRan] { taskRan[1] = true; }, 100ms);
+    thread.scheduleTask([&taskRan] { taskRan[2] = true; }, 200ms);
+    thread.scheduleTask([&taskRan] { taskRan[3] = true; }, 400ms);
+    auto handle4 = thread.scheduleTask([&taskRan] { taskRan[4] = true; }, 200ms);
+    thread.scheduleTask([&taskRan] { taskRan[5] = true; }, 200ms);
+
+    // Task 1 should trigger around 100ms.
+    std::this_thread::sleep_until(startTime + 100ms - kJitter);
+    ASSERT_FALSE(taskRan[0]);
+    ASSERT_FALSE(taskRan[1]);
+    ASSERT_FALSE(taskRan[2]);
+    ASSERT_FALSE(taskRan[3]);
+    ASSERT_FALSE(taskRan[4]);
+    ASSERT_FALSE(taskRan[5]);
+
+    std::this_thread::sleep_until(startTime + 100ms + kJitter);
+    ASSERT_FALSE(taskRan[0]);
+    ASSERT_TRUE(taskRan[1]);
+    ASSERT_FALSE(taskRan[2]);
+    ASSERT_FALSE(taskRan[3]);
+    ASSERT_FALSE(taskRan[4]);
+    ASSERT_FALSE(taskRan[5]);
+
+    // Cancel task 4 before it gets a chance to run.
+    thread.cancelTask(handle4);
+
+    // Tasks 2 and 5 should trigger around 200ms.
+    std::this_thread::sleep_until(startTime + 200ms - kJitter);
+    ASSERT_FALSE(taskRan[0]);
+    ASSERT_TRUE(taskRan[1]);
+    ASSERT_FALSE(taskRan[2]);
+    ASSERT_FALSE(taskRan[3]);
+    ASSERT_FALSE(taskRan[4]);
+    ASSERT_FALSE(taskRan[5]);
+
+    std::this_thread::sleep_until(startTime + 200ms + kJitter);
+    ASSERT_FALSE(taskRan[0]);
+    ASSERT_TRUE(taskRan[1]);
+    ASSERT_TRUE(taskRan[2]);
+    ASSERT_FALSE(taskRan[3]);
+    ASSERT_FALSE(taskRan[4]);
+    ASSERT_TRUE(taskRan[5]);
+
+    // Task 0 should trigger around 300ms.
+    std::this_thread::sleep_until(startTime + 300ms - kJitter);
+    ASSERT_FALSE(taskRan[0]);
+    ASSERT_TRUE(taskRan[1]);
+    ASSERT_TRUE(taskRan[2]);
+    ASSERT_FALSE(taskRan[3]);
+    ASSERT_FALSE(taskRan[4]);
+    ASSERT_TRUE(taskRan[5]);
+
+    std::this_thread::sleep_until(startTime + 300ms + kJitter);
+    ASSERT_TRUE(taskRan[0]);
+    ASSERT_TRUE(taskRan[1]);
+    ASSERT_TRUE(taskRan[2]);
+    ASSERT_FALSE(taskRan[3]);
+    ASSERT_FALSE(taskRan[4]);
+    ASSERT_TRUE(taskRan[5]);
+
+    // Task 3 should trigger around 400ms.
+    std::this_thread::sleep_until(startTime + 400ms - kJitter);
+    ASSERT_TRUE(taskRan[0]);
+    ASSERT_TRUE(taskRan[1]);
+    ASSERT_TRUE(taskRan[2]);
+    ASSERT_FALSE(taskRan[3]);
+    ASSERT_FALSE(taskRan[4]);
+    ASSERT_TRUE(taskRan[5]);
+
+    std::this_thread::sleep_until(startTime + 400ms + kJitter);
+    ASSERT_TRUE(taskRan[0]);
+    ASSERT_TRUE(taskRan[1]);
+    ASSERT_TRUE(taskRan[2]);
+    ASSERT_TRUE(taskRan[3]);
+    ASSERT_FALSE(taskRan[4]);
+    ASSERT_TRUE(taskRan[5]);
+}
+
+
+}  // namespace
+}  // namespace android