new file mode 100644
--- /dev/null
+++ b/ipc/unixsocket/ConnectionOrientedSocket.cpp
@@ -0,0 +1,19 @@
+/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ConnectionOrientedSocket.h"
+
+namespace mozilla {
+namespace ipc {
+
+ConnectionOrientedSocketIO::~ConnectionOrientedSocketIO()
+{ }
+
+ConnectionOrientedSocket::~ConnectionOrientedSocket()
+{ }
+
+}
+}

new file mode 100644
--- /dev/null
+++ b/ipc/unixsocket/ConnectionOrientedSocket.h
@@ -0,0 +1,47 @@
+/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_ipc_connectionorientedsocket_h
+#define mozilla_ipc_connectionorientedsocket_h
+
+#include <sys/socket.h>
+#include "nsError.h"
+
+namespace mozilla {
+namespace ipc {
+
+union sockaddr_any;
+
+/*
+ * |ConnectionOrientedSocketIO| and |ConnectionOrientedSocket| define
+ * interfaces for implementing stream sockets on I/O and main thread.
+ * |ListenSocket| uses these classes to handle accepted sockets.
+ */
+
+class ConnectionOrientedSocketIO
+{
+public:
+  virtual nsresult Accept(int aFd,
+                          const union sockaddr_any* aAddr,
+                          socklen_t aAddrLen) = 0;
+
+protected:
+  virtual ~ConnectionOrientedSocketIO();
+};
+
+class ConnectionOrientedSocket
+{
+public:
+  virtual ConnectionOrientedSocketIO* GetIO() = 0;
+
+protected:
+  virtual ~ConnectionOrientedSocket();
+};
+
+}
+}
+
+#endif

new file mode 100644
--- /dev/null
+++ b/ipc/unixsocket/ListenSocket.cpp
@@ -0,0 +1,439 @@
+/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ListenSocket.h"
+#include <fcntl.h>
+#include "ConnectionOrientedSocket.h"
+#include "mozilla/RefPtr.h"
+#include "nsXULAppAPI.h"
+#include "UnixSocketConnector.h"
+
+static const size_t MAX_READ_SIZE = 1; /* any small constant */
+
+namespace mozilla {
+namespace ipc {
+
+//
+// ListenSocketIO
+//
+
+class ListenSocketIO MOZ_FINAL : public UnixSocketWatcher
+                               , protected SocketIOBase
+{
+public:
+  class ListenTask;
+
+  ListenSocketIO(MessageLoop* mIOLoop,
+                 ListenSocket* aListenSocket,
+                 UnixSocketConnector* aConnector,
+                 const nsACString& aAddress);
+  ~ListenSocketIO();
+
+  void                GetSocketAddr(nsAString& aAddrStr) const;
+  SocketConsumerBase* GetConsumer();
+  SocketBase*         GetSocketBase();
+
+  // Shutdown state
+  //
+
+  bool IsShutdownOnMainThread() const;
+  void ShutdownOnMainThread();
+
+  bool IsShutdownOnIOThread() const;
+  void ShutdownOnIOThread();
+
+  // Task callback methods
+  //
+
+  /**
+   * Run bind/listen to prepare for further runs of accept()
+   */
+  void Listen(ConnectionOrientedSocketIO* aCOSocketIO);
+
+  // I/O callback methods
+  //
+
+  void OnAccepted(int aFd, const sockaddr_any* aAddr,
+                  socklen_t aAddrLen) MOZ_OVERRIDE;
+  void OnConnected() MOZ_OVERRIDE;
+  void OnError(const char* aFunction, int aErrno) MOZ_OVERRIDE;
+  void OnListening() MOZ_OVERRIDE;
+
+private:
+  void FireSocketError();
+
+  // Set up flags on file descriptor.
+  static bool SetSocketFlags(int aFd);
+
+  /**
+   * Consumer pointer. Non-thread safe RefPtr, so should only be manipulated
+   * directly from main thread. All non-main-thread accesses should happen with
+   * mIO as container.
+   */
+  RefPtr<ListenSocket> mListenSocket;
+
+  /**
+   * Connector object used to create the connection we are currently using.
+   */
+  nsAutoPtr<UnixSocketConnector> mConnector;
+
+  /**
+   * If true, do not requeue whatever task we're running
+   */
+  bool mShuttingDownOnIOThread;
+
+  /**
+   * Address we are connecting to, assuming we are creating a client connection.
+   */
+  nsCString mAddress;
+
+  /**
+   * Size of the socket address struct
+   */
+  socklen_t mAddrSize;
+
+  /**
+   * Address struct of the socket currently in use
+   */
+  sockaddr_any mAddr;
+
+  ConnectionOrientedSocketIO* mCOSocketIO;
+};
+
+ListenSocketIO::ListenSocketIO(MessageLoop* mIOLoop,
+                               ListenSocket* aListenSocket,
+                               UnixSocketConnector* aConnector,
+                               const nsACString& aAddress)
+: UnixSocketWatcher(mIOLoop)
+, SocketIOBase(MAX_READ_SIZE)
+, mListenSocket(aListenSocket)
+, mConnector(aConnector)
+, mShuttingDownOnIOThread(false)
+, mAddress(aAddress)
+, mCOSocketIO(nullptr)
+{
+  MOZ_ASSERT(mListenSocket);
+  MOZ_ASSERT(mConnector);
+}
+
+ListenSocketIO::~ListenSocketIO()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(IsShutdownOnMainThread());
+}
+
+void
+ListenSocketIO::GetSocketAddr(nsAString& aAddrStr) const
+{
+  if (!mConnector) {
+    NS_WARNING("No connector to get socket address from!");
+    aAddrStr.Truncate();
+    return;
+  }
+  mConnector->GetSocketAddr(mAddr, aAddrStr);
+}
+
+SocketBase*
+ListenSocketIO::GetSocketBase()
+{
+  return mListenSocket.get();
+}
+
+bool
+ListenSocketIO::IsShutdownOnMainThread() const
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  return mListenSocket == nullptr;
+}
+
+void
+ListenSocketIO::ShutdownOnMainThread()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!IsShutdownOnMainThread());
+
+  mListenSocket = nullptr;
+}
+
+bool
+ListenSocketIO::IsShutdownOnIOThread() const
+{
+  return mShuttingDownOnIOThread;
+}
+
+void
+ListenSocketIO::ShutdownOnIOThread()
+{
+  MOZ_ASSERT(!NS_IsMainThread());
+  MOZ_ASSERT(!mShuttingDownOnIOThread);
+
+  Close(); // will also remove fd from I/O loop
+  mShuttingDownOnIOThread = true;
+}
+
+void
+ListenSocketIO::Listen(ConnectionOrientedSocketIO* aCOSocketIO)
+{
+  MOZ_ASSERT(MessageLoopForIO::current() == GetIOLoop());
+  MOZ_ASSERT(mConnector);
+  MOZ_ASSERT(aCOSocketIO);
+
+  if (!IsOpen()) {
+    int fd = mConnector->Create();
+    if (fd < 0) {
+      NS_WARNING("Cannot create socket fd!");
+      FireSocketError();
+      return;
+    }
+    if (!SetSocketFlags(fd)) {
+      NS_WARNING("Cannot set socket flags!");
+      FireSocketError();
+      return;
+    }
+    SetFd(fd);
+  }
+
+  mCOSocketIO = aCOSocketIO;
+
+  // This will set things we don't particularly care about, but
+  // it will hand back the correct structure size which is what
+  // we do care about.
+  if (!mConnector->CreateAddr(true, mAddrSize, mAddr, nullptr)) {
+    NS_WARNING("Cannot create socket address!");
+    FireSocketError();
+    return;
+  }
+
+  // calls OnListening on success, or OnError otherwise
+  nsresult rv = UnixSocketWatcher::Listen(
+    reinterpret_cast<struct sockaddr*>(&mAddr), mAddrSize);
+  NS_WARN_IF(NS_FAILED(rv));
+}
+
+void
+ListenSocketIO::OnAccepted(int aFd,
+                           const sockaddr_any* aAddr,
+                           socklen_t aAddrLen)
+{
+  MOZ_ASSERT(MessageLoopForIO::current() == GetIOLoop());
+  MOZ_ASSERT(GetConnectionStatus() == SOCKET_IS_LISTENING);
+  MOZ_ASSERT(mCOSocketIO);
+
+  RemoveWatchers(READ_WATCHER|WRITE_WATCHER);
+
+  nsRefPtr<nsRunnable> runnable;
+
+  if (NS_SUCCEEDED(mCOSocketIO->Accept(aFd, aAddr, aAddrLen))) {
+    runnable =
+      new SocketIOEventRunnable<ListenSocketIO>(
+        this, SocketIOEventRunnable<ListenSocketIO>::CONNECT_SUCCESS);
+    return;
+  } else {
+    runnable =
+      new SocketIOEventRunnable<ListenSocketIO>(
+        this, SocketIOEventRunnable<ListenSocketIO>::CONNECT_ERROR);
+  }
+
+  NS_DispatchToMainThread(runnable);
+}
+
+void
+ListenSocketIO::OnConnected()
+{
+  MOZ_ASSERT(MessageLoopForIO::current() == GetIOLoop());
+
+  NS_NOTREACHED("Invalid call to |ListenSocketIO::OnConnected|");
+}
+
+void
+ListenSocketIO::OnListening()
+{
+  MOZ_ASSERT(MessageLoopForIO::current() == GetIOLoop());
+  MOZ_ASSERT(GetConnectionStatus() == SOCKET_IS_LISTENING);
+
+  if (!mConnector->SetUpListenSocket(GetFd())) {
+    NS_WARNING("Could not set up listen socket!");
+    FireSocketError();
+    return;
+  }
+
+  AddWatchers(READ_WATCHER, true);
+}
+
+void
+ListenSocketIO::OnError(const char* aFunction, int aErrno)
+{
+  MOZ_ASSERT(MessageLoopForIO::current() == GetIOLoop());
+
+  UnixFdWatcher::OnError(aFunction, aErrno);
+  FireSocketError();
+}
+
+void
+ListenSocketIO::FireSocketError()
+{
+  MOZ_ASSERT(MessageLoopForIO::current() == GetIOLoop());
+
+  // Clean up watchers, statuses, fds
+  Close();
+
+  // Tell the main thread we've errored
+  nsRefPtr<nsRunnable> r =
+    new SocketIOEventRunnable<ListenSocketIO>(
+      this, SocketIOEventRunnable<ListenSocketIO>::CONNECT_ERROR);
+
+  NS_DispatchToMainThread(r);
+}
+
+bool
+ListenSocketIO::SetSocketFlags(int aFd)
+{
+  static const int reuseaddr = 1;
+
+  // Set socket addr to be reused even if kernel is still waiting to close
+  int res = setsockopt(aFd, SOL_SOCKET, SO_REUSEADDR,
+                       &reuseaddr, sizeof(reuseaddr));
+  if (res < 0) {
+    return false;
+  }
+
+  // Set close-on-exec bit.
+  int flags = TEMP_FAILURE_RETRY(fcntl(aFd, F_GETFD));
+  if (-1 == flags) {
+    return false;
+  }
+  flags |= FD_CLOEXEC;
+  if (-1 == TEMP_FAILURE_RETRY(fcntl(aFd, F_SETFD, flags))) {
+    return false;
+  }
+
+  // Set non-blocking status flag.
+  flags = TEMP_FAILURE_RETRY(fcntl(aFd, F_GETFL));
+  if (-1 == flags) {
+    return false;
+  }
+  flags |= O_NONBLOCK;
+  if (-1 == TEMP_FAILURE_RETRY(fcntl(aFd, F_SETFL, flags))) {
+    return false;
+  }
+
+  return true;
+}
+
+//
+// Socket tasks
+//
+
+class ListenSocketIO::ListenTask MOZ_FINAL
+  : public SocketIOTask<ListenSocketIO>
+{
+public:
+  ListenTask(ListenSocketIO* aIO, ConnectionOrientedSocketIO* aCOSocketIO)
+  : SocketIOTask<ListenSocketIO>(aIO)
+  , mCOSocketIO(aCOSocketIO)
+  {
+    MOZ_ASSERT(mCOSocketIO);
+  }
+
+  void Run() MOZ_OVERRIDE
+  {
+    MOZ_ASSERT(!NS_IsMainThread());
+
+    if (!IsCanceled()) {
+      GetIO()->Listen(mCOSocketIO);
+    }
+  }
+
+private:
+  ConnectionOrientedSocketIO* mCOSocketIO;
+};
+
+//
+// UnixSocketConsumer
+//
+
+ListenSocket::ListenSocket()
+: mIO(nullptr)
+{ }
+
+ListenSocket::~ListenSocket()
+{
+  MOZ_ASSERT(!mIO);
+}
+
+void
+ListenSocket::Close()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!mIO) {
+    return;
+  }
+
+  // From this point on, we consider mIO as being deleted. We sever
+  // the relationship here so any future calls to listen or connect
+  // will create a new implementation.
+  mIO->ShutdownOnMainThread();
+
+  XRE_GetIOMessageLoop()->PostTask(
+    FROM_HERE, new SocketIOShutdownTask<ListenSocketIO>(mIO));
+
+  mIO = nullptr;
+
+  NotifyDisconnect();
+}
+
+bool
+ListenSocket::Listen(UnixSocketConnector* aConnector,
+                     ConnectionOrientedSocket* aCOSocket)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aConnector);
+  MOZ_ASSERT(aCOSocket);
+
+  nsAutoPtr<UnixSocketConnector> connector(aConnector);
+
+  if (mIO) {
+    NS_WARNING("Socket already connecting/connected!");
+    return false;
+  }
+
+  mIO = new ListenSocketIO(
+    XRE_GetIOMessageLoop(), this, connector.forget(), EmptyCString());
+
+  // Prepared I/O object, now start listening.
+  return Listen(aCOSocket);
+}
+
+bool
+ListenSocket::Listen(ConnectionOrientedSocket* aCOSocket)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mIO);
+  MOZ_ASSERT(aCOSocket);
+
+  SetConnectionStatus(SOCKET_LISTENING);
+
+  XRE_GetIOMessageLoop()->PostTask(
+    FROM_HERE, new ListenSocketIO::ListenTask(mIO, aCOSocket->GetIO()));
+
+  return true;
+}
+
+void
+ListenSocket::GetSocketAddr(nsAString& aAddrStr)
+{
+  aAddrStr.Truncate();
+  if (!mIO || GetConnectionStatus() != SOCKET_CONNECTED) {
+    NS_WARNING("No socket currently open!");
+    return;
+  }
+  mIO->GetSocketAddr(aAddrStr);
+}
+
+} // namespace ipc
+} // namespace mozilla

new file mode 100644
--- /dev/null
+++ b/ipc/unixsocket/ListenSocket.h
@@ -0,0 +1,78 @@
+/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_ipc_listensocket_h
+#define mozilla_ipc_listensocket_h
+
+#include "nsString.h"
+#include "mozilla/ipc/SocketBase.h"
+
+namespace mozilla {
+namespace ipc {
+
+class ConnectionOrientedSocket;
+class ListenSocketIO;
+class UnixSocketConnector;
+
+class ListenSocket : public SocketBase
+{
+protected:
+  virtual ~ListenSocket();
+
+public:
+  ListenSocket();
+
+  /**
+   * Starts a task on the socket that will try to accept a new connection
+   * in a non-blocking manner.
+   *
+   * @param aConnector Connector object for socket-type-specific functions
+   * @param aCOSocket The connection-oriented socket for handling the
+   *                  accepted connection.
+   *
+   * @return true on listen started, false otherwise
+   */
+  bool Listen(UnixSocketConnector* aConnector,
+              ConnectionOrientedSocket* aCOSocket);
+
+  /**
+   * Starts a task on the socket that will try to accept a new connection
+   * in a non-blocking manner. This method re-uses a previously created
+   * listen socket.
+   *
+   * @param aCOSocket The connection-oriented socket for handling the
+   *                  accepted connection.
+   *
+   * @return true on listen started, false otherwise
+   */
+  bool Listen(ConnectionOrientedSocket* aCOSocket);
+
+  /**
+   * Queues the internal representation of socket for deletion. Can be called
+   * from main thread.
+   */
+  void Close();
+
+  /**
+   * Get the current sockaddr for the socket
+   */
+  void GetSocketAddr(nsAString& aAddrStr);
+
+private:
+
+  // Legacy interface from |SocketBase|; should be replaced by |Close|.
+  void CloseSocket() MOZ_OVERRIDE
+  {
+    Close();
+  }
+
+  ListenSocketIO* mIO;
+};
+
+} // namespace ipc
+} // namepsace mozilla
+
+#endif // mozilla_ipc_listensocket_h

--- a/ipc/unixsocket/moz.build
+++ b/ipc/unixsocket/moz.build
@@ -1,21 +1,25 @@
 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 EXPORTS.mozilla.ipc += [
+    'ConnectionOrientedSocket.h',
+    'ListenSocket.h',
     'SocketBase.h',
     'UnixSocket.h',
     'UnixSocketConnector.h'
 ]
 
 SOURCES += [
+    'ConnectionOrientedSocket.cpp',
+    'ListenSocket.cpp',
     'SocketBase.cpp',
     'UnixSocket.cpp',
     'UnixSocketConnector.cpp'
 ]
 
 FAIL_ON_WARNINGS = True
 
 include('/ipc/chromium/chromium-config.mozbuild')