diff --git a/libs/vr/libpdx/Android.bp b/libs/vr/libpdx/Android.bp
index f55e994..8fce140 100644
--- a/libs/vr/libpdx/Android.bp
+++ b/libs/vr/libpdx/Android.bp
@@ -5,12 +5,15 @@
         "-Wall",
         "-Wextra",
         "-Werror",
+        "-DLOG_TAG=\"libpdx\"",
+        "-DTRACE=0",
     ],
     export_include_dirs: ["private"],
     local_include_dirs: ["private"],
     srcs: [
         "client.cpp",
         "service.cpp",
+        "service_dispatcher.cpp",
         "status.cpp",
     ],
 }
diff --git a/libs/vr/libpdx/client.cpp b/libs/vr/libpdx/client.cpp
index bfa2d87..a01c4d6 100644
--- a/libs/vr/libpdx/client.cpp
+++ b/libs/vr/libpdx/client.cpp
@@ -1,6 +1,5 @@
 #include "pdx/client.h"
 
-#define LOG_TAG "ServiceFramework"
 #include <log/log.h>
 
 #include <pdx/trace.h>
diff --git a/libs/vr/libpdx/mock_tests.cpp b/libs/vr/libpdx/mock_tests.cpp
index 76fd154..4143837 100644
--- a/libs/vr/libpdx/mock_tests.cpp
+++ b/libs/vr/libpdx/mock_tests.cpp
@@ -3,7 +3,6 @@
 #include <pdx/mock_client_channel_factory.h>
 #include <pdx/mock_message_reader.h>
 #include <pdx/mock_message_writer.h>
-#include <pdx/mock_service_dispatcher.h>
 #include <pdx/mock_service_endpoint.h>
 
 TEST(MockTypes, Instantiation) {
@@ -15,6 +14,5 @@
   android::pdx::MockMessageReader message_reader;
   android::pdx::MockOutputResourceMapper output_resource_mapper;
   android::pdx::MockMessageWriter message_writer;
-  android::pdx::MockServiceDispatcher service_dispatcher;
   android::pdx::MockEndpoint endpoint;
 }
diff --git a/libs/vr/libpdx/private/pdx/mock_service_dispatcher.h b/libs/vr/libpdx/private/pdx/mock_service_dispatcher.h
deleted file mode 100644
index 9b51d30..0000000
--- a/libs/vr/libpdx/private/pdx/mock_service_dispatcher.h
+++ /dev/null
@@ -1,24 +0,0 @@
-#ifndef ANDROID_PDX_MOCK_SERVICE_DISPATCHER_H_
-#define ANDROID_PDX_MOCK_SERVICE_DISPATCHER_H_
-
-#include <gmock/gmock.h>
-#include <pdx/service_dispatcher.h>
-
-namespace android {
-namespace pdx {
-
-class MockServiceDispatcher : public ServiceDispatcher {
- public:
-  MOCK_METHOD1(AddService, int(const std::shared_ptr<Service>& service));
-  MOCK_METHOD1(RemoveService, int(const std::shared_ptr<Service>& service));
-  MOCK_METHOD0(ReceiveAndDispatch, int());
-  MOCK_METHOD1(ReceiveAndDispatch, int(int timeout));
-  MOCK_METHOD0(EnterDispatchLoop, int());
-  MOCK_METHOD1(SetCanceled, void(bool cancel));
-  MOCK_CONST_METHOD0(IsCanceled, bool());
-};
-
-}  // namespace pdx
-}  // namespace android
-
-#endif  // ANDROID_PDX_MOCK_SERVICE_DISPATCHER_H_
diff --git a/libs/vr/libpdx/private/pdx/mock_service_endpoint.h b/libs/vr/libpdx/private/pdx/mock_service_endpoint.h
index e741d4a..7f829e7 100644
--- a/libs/vr/libpdx/private/pdx/mock_service_endpoint.h
+++ b/libs/vr/libpdx/private/pdx/mock_service_endpoint.h
@@ -66,6 +66,7 @@
   MOCK_METHOD0(AllocateMessageState, void*());
   MOCK_METHOD1(FreeMessageState, void(void* state));
   MOCK_METHOD0(Cancel, Status<void>());
+  MOCK_CONST_METHOD0(epoll_fd, int());
 };
 
 }  // namespace pdx
diff --git a/libs/vr/libpdx/private/pdx/service_dispatcher.h b/libs/vr/libpdx/private/pdx/service_dispatcher.h
index c5e342a..bd27000 100644
--- a/libs/vr/libpdx/private/pdx/service_dispatcher.h
+++ b/libs/vr/libpdx/private/pdx/service_dispatcher.h
@@ -2,6 +2,11 @@
 #define ANDROID_PDX_SERVICE_DISPATCHER_H_
 
 #include <memory>
+#include <mutex>
+#include <unordered_map>
+#include <vector>
+
+#include <pdx/file_handle.h>
 
 namespace android {
 namespace pdx {
@@ -15,7 +20,10 @@
  */
 class ServiceDispatcher {
  public:
-  virtual ~ServiceDispatcher() = default;
+  // Get a new instance of ServiceDispatcher, or return nullptr if init failed.
+  static std::unique_ptr<ServiceDispatcher> Create();
+
+  ~ServiceDispatcher();
 
   /*
    * Adds a service to the list of services handled by this dispatcher. This
@@ -24,7 +32,7 @@
    *
    * Returns 0 on success; -EEXIST if the service was already added.
    */
-  virtual int AddService(const std::shared_ptr<Service>& service) = 0;
+  int AddService(const std::shared_ptr<Service>& service);
 
   /*
    * Removes a service from this dispatcher. This will fail if any threads are
@@ -33,7 +41,7 @@
    * Returns 0 on success; -ENOENT if the service was not previously added;
    * -EBUSY if there are threads in the dispatcher.
    */
-  virtual int RemoveService(const std::shared_ptr<Service>& service) = 0;
+  int RemoveService(const std::shared_ptr<Service>& service);
 
   /*
    * Receive and dispatch one set of messages. Multiple threads may enter this
@@ -42,14 +50,14 @@
    * cycle, requiring an external loop. This is useful when other work needs
    * to be done in the service dispatch loop.
    */
-  virtual int ReceiveAndDispatch() = 0;
+  int ReceiveAndDispatch();
 
   /*
    * Same as above with timeout in milliseconds. A negative value means
    * infinite timeout, while a value of 0 means return immediately if no
    * messages are available to receive.
    */
-  virtual int ReceiveAndDispatch(int timeout) = 0;
+  int ReceiveAndDispatch(int timeout);
 
   /*
    * Receive and dispatch messages until canceled. When more than one thread
@@ -58,19 +66,39 @@
    * hands Message instances (via move assignment) over to a queue of threads
    * (or perhaps one of several) to handle.
    */
-  virtual int EnterDispatchLoop() = 0;
+  int EnterDispatchLoop();
 
   /*
    * Sets the canceled state of the dispatcher. When canceled is true, any
    * threads blocked waiting for messages will return. This method waits until
    * all dispatch threads have exited the dispatcher.
    */
-  virtual void SetCanceled(bool cancel) = 0;
+  void SetCanceled(bool cancel);
 
   /*
    * Gets the canceled state of the dispatcher.
    */
-  virtual bool IsCanceled() const = 0;
+  bool IsCanceled() const;
+
+ private:
+  ServiceDispatcher();
+
+  // Internal thread accounting.
+  int ThreadEnter();
+  void ThreadExit();
+
+  std::mutex mutex_;
+  std::condition_variable condition_;
+  std::atomic<bool> canceled_{false};
+
+  std::vector<std::shared_ptr<Service>> services_;
+
+  int thread_count_ = 0;
+  LocalHandle event_fd_;
+  LocalHandle epoll_fd_;
+
+  ServiceDispatcher(const ServiceDispatcher&) = delete;
+  void operator=(const ServiceDispatcher&) = delete;
 };
 
 }  // namespace pdx
diff --git a/libs/vr/libpdx/private/pdx/service_endpoint.h b/libs/vr/libpdx/private/pdx/service_endpoint.h
index 28bd6bc..d581894 100644
--- a/libs/vr/libpdx/private/pdx/service_endpoint.h
+++ b/libs/vr/libpdx/private/pdx/service_endpoint.h
@@ -136,6 +136,10 @@
   // Cancels the endpoint, unblocking any receiver threads waiting for a
   // message.
   virtual Status<void> Cancel() = 0;
+
+  // Returns an fd that can be used with epoll() to wait for incoming messages
+  // from this endpoint.
+  virtual int epoll_fd() const = 0;
 };
 
 }  // namespace pdx
diff --git a/libs/vr/libpdx/service.cpp b/libs/vr/libpdx/service.cpp
index fab4770..1d3b62a 100644
--- a/libs/vr/libpdx/service.cpp
+++ b/libs/vr/libpdx/service.cpp
@@ -1,4 +1,3 @@
-#define LOG_TAG "ServiceFramework"
 #include "pdx/service.h"
 
 #include <fcntl.h>
@@ -10,8 +9,6 @@
 
 #include <pdx/trace.h>
 
-#define TRACE 0
-
 namespace android {
 namespace pdx {
 
diff --git a/libs/vr/libpdx/service_dispatcher.cpp b/libs/vr/libpdx/service_dispatcher.cpp
new file mode 100644
index 0000000..b112fa3
--- /dev/null
+++ b/libs/vr/libpdx/service_dispatcher.cpp
@@ -0,0 +1,192 @@
+#include <pdx/service_dispatcher.h>
+
+#include <errno.h>
+#include <log/log.h>
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+
+#include <pdx/service.h>
+#include <pdx/service_endpoint.h>
+
+static const int kMaxEventsPerLoop = 128;
+
+namespace android {
+namespace pdx {
+
+std::unique_ptr<ServiceDispatcher> ServiceDispatcher::Create() {
+  std::unique_ptr<ServiceDispatcher> dispatcher{new ServiceDispatcher()};
+  if (!dispatcher->epoll_fd_ || !dispatcher->event_fd_) {
+    dispatcher.reset();
+  }
+
+  return dispatcher;
+}
+
+ServiceDispatcher::ServiceDispatcher() {
+  event_fd_.Reset(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK));
+  if (!event_fd_) {
+    ALOGE("Failed to create event fd because: %s\n", strerror(errno));
+    return;
+  }
+
+  epoll_fd_.Reset(epoll_create1(EPOLL_CLOEXEC));
+  if (!epoll_fd_) {
+    ALOGE("Failed to create epoll fd because: %s\n", strerror(errno));
+    return;
+  }
+
+  // Use "this" as a unique pointer to distinguish the event fd from all
+  // the other entries that point to instances of Service.
+  epoll_event event;
+  event.events = EPOLLIN;
+  event.data.ptr = this;
+
+  if (epoll_ctl(epoll_fd_.Get(), EPOLL_CTL_ADD, event_fd_.Get(), &event) < 0) {
+    ALOGE("Failed to add event fd to epoll fd because: %s\n", strerror(errno));
+
+    // Close the fds here and signal failure to the factory method.
+    event_fd_.Close();
+    epoll_fd_.Close();
+  }
+}
+
+ServiceDispatcher::~ServiceDispatcher() { SetCanceled(true); }
+
+int ServiceDispatcher::ThreadEnter() {
+  std::lock_guard<std::mutex> autolock(mutex_);
+
+  if (canceled_)
+    return -EBUSY;
+
+  thread_count_++;
+  return 0;
+}
+
+void ServiceDispatcher::ThreadExit() {
+  std::lock_guard<std::mutex> autolock(mutex_);
+  thread_count_--;
+  condition_.notify_one();
+}
+
+int ServiceDispatcher::AddService(const std::shared_ptr<Service>& service) {
+  std::lock_guard<std::mutex> autolock(mutex_);
+
+  epoll_event event;
+  event.events = EPOLLIN;
+  event.data.ptr = service.get();
+
+  if (epoll_ctl(epoll_fd_.Get(), EPOLL_CTL_ADD, service->endpoint()->epoll_fd(),
+                &event) < 0) {
+    ALOGE("Failed to add service to dispatcher because: %s\n", strerror(errno));
+    return -errno;
+  }
+
+  services_.push_back(service);
+  return 0;
+}
+
+int ServiceDispatcher::RemoveService(const std::shared_ptr<Service>& service) {
+  std::lock_guard<std::mutex> autolock(mutex_);
+
+  // It's dangerous to remove a service while other threads may be using it.
+  if (thread_count_ > 0)
+    return -EBUSY;
+
+  epoll_event dummy;  // See BUGS in man 2 epoll_ctl.
+  if (epoll_ctl(epoll_fd_.Get(), EPOLL_CTL_DEL, service->endpoint()->epoll_fd(),
+                &dummy) < 0) {
+    ALOGE("Failed to remove service from dispatcher because: %s\n",
+          strerror(errno));
+    return -errno;
+  }
+
+  services_.erase(std::remove(services_.begin(), services_.end(), service),
+                  services_.end());
+  return 0;
+}
+
+int ServiceDispatcher::ReceiveAndDispatch() { return ReceiveAndDispatch(-1); }
+
+int ServiceDispatcher::ReceiveAndDispatch(int timeout) {
+  int ret = ThreadEnter();
+  if (ret < 0)
+    return ret;
+
+  epoll_event events[kMaxEventsPerLoop];
+
+  int count = epoll_wait(epoll_fd_.Get(), events, kMaxEventsPerLoop, timeout);
+  if (count <= 0) {
+    ALOGE_IF(count < 0, "Failed to wait for epoll events because: %s\n",
+             strerror(errno));
+    ThreadExit();
+    return count < 0 ? -errno : -ETIMEDOUT;
+  }
+
+  for (int i = 0; i < count; i++) {
+    if (events[i].data.ptr == this) {
+      ThreadExit();
+      return -EBUSY;
+    } else {
+      Service* service = static_cast<Service*>(events[i].data.ptr);
+
+      ALOGI_IF(TRACE, "Dispatching message: fd=%d\n",
+               service->endpoint()->epoll_fd());
+      service->ReceiveAndDispatch();
+    }
+  }
+
+  ThreadExit();
+  return 0;
+}
+
+int ServiceDispatcher::EnterDispatchLoop() {
+  int ret = ThreadEnter();
+  if (ret < 0)
+    return ret;
+
+  epoll_event events[kMaxEventsPerLoop];
+
+  while (!IsCanceled()) {
+    int count = epoll_wait(epoll_fd_.Get(), events, kMaxEventsPerLoop, -1);
+    if (count < 0 && errno != EINTR) {
+      ALOGE("Failed to wait for epoll events because: %s\n", strerror(errno));
+      ThreadExit();
+      return -errno;
+    }
+
+    for (int i = 0; i < count; i++) {
+      if (events[i].data.ptr == this) {
+        ThreadExit();
+        return -EBUSY;
+      } else {
+        Service* service = static_cast<Service*>(events[i].data.ptr);
+
+        ALOGI_IF(TRACE, "Dispatching message: fd=%d\n",
+                 service->endpoint()->epoll_fd());
+        service->ReceiveAndDispatch();
+      }
+    }
+  }
+
+  ThreadExit();
+  return 0;
+}
+
+void ServiceDispatcher::SetCanceled(bool cancel) {
+  std::unique_lock<std::mutex> lock(mutex_);
+  canceled_ = cancel;
+
+  if (canceled_ && thread_count_ > 0) {
+    eventfd_write(event_fd_.Get(), 1);  // Signal threads to quit.
+
+    condition_.wait(lock, [this] { return !(canceled_ && thread_count_ > 0); });
+
+    eventfd_t value;
+    eventfd_read(event_fd_.Get(), &value);  // Unsignal.
+  }
+}
+
+bool ServiceDispatcher::IsCanceled() const { return canceled_; }
+
+}  // namespace pdx
+}  // namespace android