modules/video_output/win32/inhibit.c

   1 /*****************************************************************************
   2  * inhibit.c: Windows video output common code
   3  *****************************************************************************
   4  * Copyright (C) 2018 VLC authors and VideoLAN
   5  *
   6  * Authors: Steve Lhomme <robux4@ycbcr.xyz>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #ifdef HAVE_CONFIG_H
  24 # include "config.h"
  25 #endif
  26
  27 #include <vlc_common.h>
  28 #include <vlc_inhibit.h>
  29 #include <vlc_plugin.h>
  30 #include <assert.h>
  31
  32 struct vlc_inhibit_sys
  33 {
  34     vlc_mutex_t mutex;
  35     vlc_cond_t cond;
  36     vlc_thread_t thread;
  37     unsigned int mask;
  38 };
  39
  40 static void Inhibit (vlc_inhibit_t *ih, unsigned mask)
  41 {
  42     vlc_inhibit_sys_t *sys = ih->p_sys;
  43     vlc_mutex_lock(&sys->mutex);
  44     sys->mask = mask;
  45     vlc_cond_signal(&sys->cond);
  46     vlc_mutex_unlock(&sys->mutex);
  47 }
  48
  49 static void RestoreStateOnCancel( void* p_opaque )
  50 {
  51     VLC_UNUSED(p_opaque);
  52     SetThreadExecutionState( ES_CONTINUOUS );
  53 }
  54
  55 static void* Run(void* obj)
  56 {
  57     vlc_inhibit_t *ih = (vlc_inhibit_t*)obj;
  58     vlc_inhibit_sys_t *sys = ih->p_sys;
  59     EXECUTION_STATE prev_state = ES_CONTINUOUS;
  60
  61     for  (unsigned int mask = 0;;)
  62     {
  63         vlc_mutex_lock(&sys->mutex);
  64         mutex_cleanup_push(&sys->mutex);
  65         vlc_cleanup_push(RestoreStateOnCancel, ih);
  66         while (mask == sys->mask)
  67             vlc_cond_wait(&sys->cond, &sys->mutex);
  68         mask = sys->mask;
  69         vlc_mutex_unlock(&sys->mutex);
  70         vlc_cleanup_pop();
  71         vlc_cleanup_pop();
  72
  73         bool suspend = (mask & VLC_INHIBIT_DISPLAY) != 0;
  74         if (suspend)
  75             /* Prevent monitor from powering off */
  76             prev_state = SetThreadExecutionState( ES_DISPLAY_REQUIRED |
  77                                                   ES_SYSTEM_REQUIRED |
  78                                                   ES_CONTINUOUS );
  79         else
  80             SetThreadExecutionState( prev_state );
  81     }
  82     vlc_assert_unreachable();
  83 }
  84
  85 static void CloseInhibit (vlc_object_t *obj)
  86 {
  87     vlc_inhibit_t *ih = (vlc_inhibit_t*)obj;
  88     vlc_inhibit_sys_t* sys = ih->p_sys;
  89     vlc_cancel(sys->thread);
  90     vlc_join(sys->thread, NULL);
  91     vlc_cond_destroy(&sys->cond);
  92     vlc_mutex_destroy(&sys->mutex);
  93 }
  94
  95 static int OpenInhibit (vlc_object_t *obj)
  96 {
  97     vlc_inhibit_t *ih = (vlc_inhibit_t *)obj;
  98     vlc_inhibit_sys_t *sys = ih->p_sys =
  99             vlc_obj_malloc(obj, sizeof(vlc_inhibit_sys_t));
 100     if (unlikely(ih->p_sys == NULL))
 101         return VLC_ENOMEM;
 102
 103     vlc_mutex_init(&sys->mutex);
 104     vlc_cond_init(&sys->cond);
 105     sys->mask = 0;
 106
 107     /* SetThreadExecutionState always needs to be called from the same thread */
 108     if (vlc_clone(&sys->thread, Run, ih, VLC_THREAD_PRIORITY_LOW))
 109     {
 110         vlc_cond_destroy(&sys->cond);
 111         vlc_mutex_destroy(&sys->mutex);
 112         return VLC_EGENERIC;
 113     }
 114
 115     ih->inhibit = Inhibit;
 116     return VLC_SUCCESS;
 117 }
 118
 119 vlc_module_begin ()
 120     set_shortname (N_("Windows screensaver"))
 121     set_description (N_("Windows screen saver inhibition"))
 122     set_category (CAT_ADVANCED)
 123     set_subcategory (SUBCAT_ADVANCED_MISC)
 124     set_capability ("inhibit", 10)
 125     set_callbacks (OpenInhibit, CloseInhibit)
 126 vlc_module_end ()