xbmc/cores/AudioEngine/Sinks/alsa/ALSADeviceMonitor.cpp

   1 /*
   2  *  Copyright (C) 2014-2018 Team Kodi
   3  *  This file is part of Kodi - https://kodi.tv
   4  *
   5  *  SPDX-License-Identifier: GPL-2.0-or-later
   6  *  See LICENSES/README.md for more information.
   7  */
   8
   9 #include "ALSADeviceMonitor.h"
  10
  11 #include "ServiceBroker.h"
  12 #include "cores/AudioEngine/Engines/ActiveAE/ActiveAE.h"
  13 #include "utils/log.h"
  14
  15 #include "platform/linux/FDEventMonitor.h"
  16
  17 #include <libudev.h>
  18
  19 CALSADeviceMonitor::CALSADeviceMonitor() :
  20   m_udev(NULL),
  21   m_udevMonitor(NULL)
  22 {
  23 }
  24
  25 CALSADeviceMonitor::~CALSADeviceMonitor()
  26 {
  27   Stop();
  28 }
  29
  30 void CALSADeviceMonitor::Start()
  31 {
  32   int err;
  33
  34   if (!m_udev)
  35   {
  36     m_udev = udev_new();
  37     if (!m_udev)
  38     {
  39       CLog::Log(LOGWARNING, "CALSADeviceMonitor::Start - Unable to open udev handle");
  40       return;
  41     }
  42
  43     m_udevMonitor = udev_monitor_new_from_netlink(m_udev, "udev");
  44     if (!m_udevMonitor)
  45     {
  46       CLog::Log(LOGERROR, "CALSADeviceMonitor::Start - udev_monitor_new_from_netlink() failed");
  47       goto err_unref_udev;
  48     }
  49
  50     err = udev_monitor_filter_add_match_subsystem_devtype(m_udevMonitor, "sound", NULL);
  51     if (err)
  52     {
  53       CLog::Log(LOGERROR, "CALSADeviceMonitor::Start - udev_monitor_filter_add_match_subsystem_devtype() failed");
  54       goto err_unref_monitor;
  55     }
  56
  57     err = udev_monitor_enable_receiving(m_udevMonitor);
  58     if (err)
  59     {
  60       CLog::Log(LOGERROR, "CALSADeviceMonitor::Start - udev_monitor_enable_receiving() failed");
  61       goto err_unref_monitor;
  62     }
  63
  64     const auto eventMonitor = CServiceBroker::GetPlatform().GetService<CFDEventMonitor>();
  65     eventMonitor->AddFD(CFDEventMonitor::MonitoredFD(udev_monitor_get_fd(m_udevMonitor), POLLIN,
  66                                                      FDEventCallback, m_udevMonitor),
  67                         m_fdMonitorId);
  68   }
  69
  70   return;
  71
  72 err_unref_monitor:
  73   udev_monitor_unref(m_udevMonitor);
  74   m_udevMonitor = NULL;
  75 err_unref_udev:
  76   udev_unref(m_udev);
  77   m_udev = NULL;
  78 }
  79
  80 void CALSADeviceMonitor::Stop()
  81 {
  82   if (m_udev)
  83   {
  84     const auto eventMonitor = CServiceBroker::GetPlatform().GetService<CFDEventMonitor>();
  85     eventMonitor->RemoveFD(m_fdMonitorId);
  86
  87     udev_monitor_unref(m_udevMonitor);
  88     m_udevMonitor = NULL;
  89     udev_unref(m_udev);
  90     m_udev = NULL;
  91   }
  92 }
  93
  94 void CALSADeviceMonitor::FDEventCallback(int id, int fd, short revents, void *data)
  95 {
  96   struct udev_monitor *udevMonitor = (struct udev_monitor *)data;
  97   bool audioDevicesChanged = false;
  98   struct udev_device *device;
  99
 100   while ((device = udev_monitor_receive_device(udevMonitor)) != NULL)
 101   {
 102     const char* action = udev_device_get_action(device);
 103     const char* soundInitialized = udev_device_get_property_value(device, "SOUND_INITIALIZED");
 104
 105     if (!action || !soundInitialized)
 106       continue;
 107
 108     /* cardX devices emit a "change" event when ready (i.e. all subdevices added) */
 109     if (strcmp(action, "change") == 0)
 110     {
 111       CLog::Log(LOGDEBUG, "CALSADeviceMonitor - ALSA card added (\"{}\", \"{}\")",
 112                 udev_device_get_syspath(device), udev_device_get_devpath(device));
 113       audioDevicesChanged = true;
 114     }
 115     else if (strcmp(action, "remove") == 0)
 116     {
 117       CLog::Log(LOGDEBUG, "CALSADeviceMonitor - ALSA card removed");
 118       audioDevicesChanged = true;
 119     }
 120
 121     udev_device_unref(device);
 122   }
 123
 124   if (audioDevicesChanged)
 125   {
 126     CServiceBroker::GetActiveAE()->DeviceChange();
 127   }
 128 }