1 files changed, 277 insertions, 0 deletions
diff --git a/xbmc/windowing/wayland/WinEventsWayland.cpp b/xbmc/windowing/wayland/WinEventsWayland.cpp
new file mode 100644
index 0000000..4345cf0
--- /dev/null
+++ b/xbmc/windowing/wayland/WinEventsWayland.cpp
@@ -0,0 +1,277 @@
+/*
+ *  Copyright (C) 2017-2018 Team Kodi
+ *  This file is part of Kodi - https://kodi.tv
+ *
+ *  SPDX-License-Identifier: GPL-2.0-or-later
+ *  See LICENSES/README.md for more information.
+ */
+
+#include "WinEventsWayland.h"
+
+#include "ServiceBroker.h"
+#include "application/AppInboundProtocol.h"
+#include "threads/CriticalSection.h"
+#include "threads/Thread.h"
+#include "utils/log.h"
+
+#include "platform/posix/utils/FileHandle.h"
+
+#include <exception>
+#include <memory>
+#include <mutex>
+#include <system_error>
+
+#include <sys/poll.h>
+#include <unistd.h>
+#include <wayland-client.hpp>
+
+using namespace KODI::UTILS::POSIX;
+using namespace KODI::WINDOWING::WAYLAND;
+
+namespace
+{
+/**
+ * Thread for processing Wayland events
+ *
+ * While not strictly needed, reading from the Wayland display file descriptor
+ * and dispatching the resulting events is done in an extra thread here.
+ * Sometime in the future, MessagePump() might be gone and then the
+ * transition will be easier since this extra thread is already here.
+ */
+class CWinEventsWaylandThread : CThread
+{
+  wayland::display_t& m_display;
+  // Pipe used for cancelling poll() on shutdown
+  CFileHandle m_pipeRead;
+  CFileHandle m_pipeWrite;
+
+  CCriticalSection m_roundtripQueueMutex;
+  std::atomic<wayland::event_queue_t*> m_roundtripQueue{nullptr};
+  CEvent m_roundtripQueueEvent;
+
+public:
+  CWinEventsWaylandThread(wayland::display_t& display)
+  : CThread("Wayland message pump"), m_display{display}
+  {
+    std::array<int, 2> fds;
+    if (pipe(fds.data()) < 0)
+    {
+      throw std::system_error(errno, std::generic_category(), "Error creating pipe for Wayland message pump cancellation");
+    }
+    m_pipeRead.attach(fds[0]);
+    m_pipeWrite.attach(fds[1]);
+    Create();
+  }
+
+  ~CWinEventsWaylandThread() override
+  {
+    Stop();
+    // Wait for roundtrip invocation to finish
+    std::unique_lock<CCriticalSection> lock(m_roundtripQueueMutex);
+  }
+
+  void Stop()
+  {
+    CLog::Log(LOGDEBUG, "Stopping Wayland message pump");
+    // Set m_bStop
+    StopThread(false);
+    InterruptPoll();
+    // Now wait for actual exit
+    StopThread(true);
+  }
+
+  void RoundtripQueue(wayland::event_queue_t const& queue)
+  {
+    wayland::event_queue_t queueCopy{queue};
+
+    // Serialize invocations of this function - it's used very rarely and usually
+    // not in parallel anyway, and doing it avoids lots of complications
+    std::unique_lock<CCriticalSection> lock(m_roundtripQueueMutex);
+
+    m_roundtripQueueEvent.Reset();
+    // We can just set the value here since there is no other writer in parallel
+    m_roundtripQueue.store(&queueCopy);
+    // Dispatching can happen now
+
+    // Make sure we don't wait for an event to happen on the socket
+    InterruptPoll();
+
+    if (m_bStop)
+      return;
+
+    m_roundtripQueueEvent.Wait();
+  }
+
+  wayland::display_t& GetDisplay()
+  {
+    return m_display;
+  }
+
+private:
+  void InterruptPoll()
+  {
+    char c = 0;
+    if (write(m_pipeWrite, &c, 1) != 1)
+      throw std::runtime_error("Failed to write to wayland message pipe");
+  }
+
+  void Process() override
+  {
+    try
+    {
+      std::array<pollfd, 2> pollFds;
+      pollfd& waylandPoll = pollFds[0];
+      pollfd& cancelPoll = pollFds[1];
+      // Wayland filedescriptor
+      waylandPoll.fd = m_display.get_fd();
+      waylandPoll.events = POLLIN;
+      waylandPoll.revents = 0;
+      // Read end of the cancellation pipe
+      cancelPoll.fd = m_pipeRead;
+      cancelPoll.events = POLLIN;
+      cancelPoll.revents = 0;
+
+      CLog::Log(LOGDEBUG, "Starting Wayland message pump");
+
+      // Run until cancelled or error
+      while (!m_bStop)
+      {
+        // dispatch() provides no way to cancel a blocked read from the socket
+        // wl_display_disconnect would just close the socket, leading to problems
+        // with the poll() that dispatch() uses internally - so we have to implement
+        // cancellation ourselves here
+
+        // Acquire global read intent
+        wayland::read_intent readIntent = m_display.obtain_read_intent();
+        m_display.flush();
+
+        if (poll(pollFds.data(), pollFds.size(), -1) < 0)
+        {
+          if (errno == EINTR)
+          {
+            continue;
+          }
+          else
+          {
+            throw std::system_error(errno, std::generic_category(), "Error polling on Wayland socket");
+          }
+        }
+
+        if (cancelPoll.revents & POLLERR || cancelPoll.revents & POLLHUP || cancelPoll.revents & POLLNVAL)
+        {
+          throw std::runtime_error("poll() signalled error condition on poll interruption socket");
+        }
+
+        if (waylandPoll.revents & POLLERR || waylandPoll.revents & POLLHUP || waylandPoll.revents & POLLNVAL)
+        {
+          throw std::runtime_error("poll() signalled error condition on Wayland socket");
+        }
+
+        // Read events and release intent; this does not block
+        readIntent.read();
+        // Dispatch default event queue
+        m_display.dispatch_pending();
+
+        if (auto* roundtripQueue = m_roundtripQueue.exchange(nullptr))
+        {
+          m_display.roundtrip_queue(*roundtripQueue);
+          m_roundtripQueueEvent.Set();
+        }
+        if (cancelPoll.revents & POLLIN)
+        {
+          // Read away the char so we don't get another notification
+          // Indepentent from m_roundtripQueue so there are no races
+          char c;
+          if (read(m_pipeRead, &c, 1) != 1)
+            throw std::runtime_error("Error reading from wayland message pipe");
+        }
+      }
+
+      CLog::Log(LOGDEBUG, "Wayland message pump stopped");
+    }
+    catch (std::exception const& e)
+    {
+      // FIXME CThread::OnException is very badly named and should probably go away
+      // FIXME Thread exception handling is seriously broken:
+      // Exceptions will be swallowed and do not terminate the program.
+      // Even XbmcCommons::UncheckedException which claims to be there for just this
+      // purpose does not cause termination, the log message will just be slightly different.
+
+      // But here, going on would be meaningless, so do a hard exit
+      CLog::Log(LOGFATAL, "Exception in Wayland message pump, exiting: {}", e.what());
+      std::terminate();
+    }
+
+    // Wake up if someone is still waiting for roundtrip, won't happen anytime soon...
+    m_roundtripQueueEvent.Set();
+  }
+};
+
+std::unique_ptr<CWinEventsWaylandThread> g_WlMessagePump{nullptr};
+
+}
+
+void CWinEventsWayland::SetDisplay(wayland::display_t* display)
+{
+  if (display && !g_WlMessagePump)
+  {
+    // Start message processing as soon as we have a display
+    g_WlMessagePump.reset(new CWinEventsWaylandThread(*display));
+  }
+  else if (g_WlMessagePump)
+  {
+    // Stop if display is set to nullptr
+    g_WlMessagePump.reset();
+  }
+}
+
+void CWinEventsWayland::Flush()
+{
+  if (g_WlMessagePump)
+  {
+    g_WlMessagePump->GetDisplay().flush();
+  }
+}
+
+void CWinEventsWayland::RoundtripQueue(const wayland::event_queue_t& queue)
+{
+  if (g_WlMessagePump)
+  {
+    g_WlMessagePump->RoundtripQueue(queue);
+  }
+}
+
+bool CWinEventsWayland::MessagePump()
+{
+  std::shared_ptr<CAppInboundProtocol> appPort = CServiceBroker::GetAppPort();
+  // Forward any events that may have been pushed to our queue
+  while (true)
+  {
+    XBMC_Event event;
+    {
+      // Scoped lock for reentrancy
+      std::unique_lock<CCriticalSection> lock(m_queueMutex);
+
+      if (m_queue.empty())
+      {
+        break;
+      }
+
+      // First get event and remove it from the queue, then pass it on - be aware that this
+      // function must be reentrant
+      event = m_queue.front();
+      m_queue.pop();
+    }
+
+    if (appPort)
+      appPort->OnEvent(event);
+  }
+
+  return true;
+}
+
+void CWinEventsWayland::MessagePush(XBMC_Event* ev)
+{
+  std::unique_lock<CCriticalSection> lock(m_queueMutex);
+  m_queue.emplace(*ev);
+}