kc3-lang/SDL/src/core/linux/SDL_dbus.h

• Show log

  Commit

• Hash : f4a56d7e
  Author :
  Date : 2020-03-30T14:26:15
  

  Enable thread-safety features in libdbus
  
  There are multiple SDL APIs that internally sink into dbus calls, e.g. battery
  status, thread priority. If those calls happen in different threads simultaneously
  it can result in dbus crashes.
  
  To abide by dbus's multithreading guidelines we must call dbus_threads_init_default()
  to enable dbus's internal locking mechanisms:
  https://dbus.freedesktop.org/doc/api/html/group__DBusThreads.html#gac7b8a7001befc3eaa8c6b043151008dc
  
  Additionally, access to a DBusMessage must be synchronized between threads.
  SDL was already abiding that guideline as the DBusMessage structs aren't shared.
  
  The following email from the dbus mailing list hints that arbitrating access to
  the DBusConnection on the SDL may also be required:
  https://lists.freedesktop.org/archives/dbus/2017-September/017306.html
  

Download

• src/core/linux/SDL_dbus.h

• /*
    Simple DirectMedia Layer
    Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
  
    This software is provided 'as-is', without any express or implied
    warranty.  In no event will the authors be held liable for any damages
    arising from the use of this software.
  
    Permission is granted to anyone to use this software for any purpose,
    including commercial applications, and to alter it and redistribute it
    freely, subject to the following restrictions:
  
    1. The origin of this software must not be misrepresented; you must not
       claim that you wrote the original software. If you use this software
       in a product, an acknowledgment in the product documentation would be
       appreciated but is not required.
    2. Altered source versions must be plainly marked as such, and must not be
       misrepresented as being the original software.
    3. This notice may not be removed or altered from any source distribution.
  */
  
  #include "../../SDL_internal.h"
  
  #ifndef SDL_dbus_h_
  #define SDL_dbus_h_
  
  #ifdef HAVE_DBUS_DBUS_H
  #define SDL_USE_LIBDBUS 1
  #include "SDL_stdinc.h"
  #include <dbus/dbus.h>
  
  
  typedef struct SDL_DBusContext {
      DBusConnection *session_conn;
      DBusConnection *system_conn;
  
      DBusConnection *(*bus_get_private)(DBusBusType, DBusError *);
      dbus_bool_t (*bus_register)(DBusConnection *, DBusError *);
      void (*bus_add_match)(DBusConnection *, const char *, DBusError *);
      DBusConnection * (*connection_open_private)(const char *, DBusError *);
      void (*connection_set_exit_on_disconnect)(DBusConnection *, dbus_bool_t);
      dbus_bool_t (*connection_get_is_connected)(DBusConnection *);
      dbus_bool_t (*connection_add_filter)(DBusConnection *, DBusHandleMessageFunction, void *, DBusFreeFunction);
      dbus_bool_t (*connection_try_register_object_path)(DBusConnection *, const char *,
          const DBusObjectPathVTable *, void *, DBusError *);
      dbus_bool_t (*connection_send)(DBusConnection *, DBusMessage *, dbus_uint32_t *);
      DBusMessage *(*connection_send_with_reply_and_block)(DBusConnection *, DBusMessage *, int, DBusError *);
      void (*connection_close)(DBusConnection *);
      void (*connection_unref)(DBusConnection *);
      void (*connection_flush)(DBusConnection *);
      dbus_bool_t (*connection_read_write)(DBusConnection *, int);
      DBusDispatchStatus (*connection_dispatch)(DBusConnection *);
      dbus_bool_t (*message_is_signal)(DBusMessage *, const char *, const char *); 
      DBusMessage *(*message_new_method_call)(const char *, const char *, const char *, const char *);
      dbus_bool_t (*message_append_args)(DBusMessage *, int, ...);
      dbus_bool_t (*message_append_args_valist)(DBusMessage *, int, va_list);
      dbus_bool_t (*message_get_args)(DBusMessage *, DBusError *, int, ...);
      dbus_bool_t (*message_get_args_valist)(DBusMessage *, DBusError *, int, va_list);
      dbus_bool_t (*message_iter_init)(DBusMessage *, DBusMessageIter *);
      dbus_bool_t (*message_iter_next)(DBusMessageIter *);
      void (*message_iter_get_basic)(DBusMessageIter *, void *);
      int (*message_iter_get_arg_type)(DBusMessageIter *);
      void (*message_iter_recurse)(DBusMessageIter *, DBusMessageIter *); 
      void (*message_unref)(DBusMessage *);
      dbus_bool_t (*threads_init_default)(void);
      void (*error_init)(DBusError *);
      dbus_bool_t (*error_is_set)(const DBusError *);
      void (*error_free)(DBusError *);
      char *(*get_local_machine_id)(void);
      void (*free)(void *);
      void (*free_string_array)(char **);
      void (*shutdown)(void);
  
  } SDL_DBusContext;
  
  extern void SDL_DBus_Init(void);
  extern void SDL_DBus_Quit(void);
  extern SDL_DBusContext * SDL_DBus_GetContext(void);
  
  /* These use the built-in Session connection. */
  extern SDL_bool SDL_DBus_CallMethod(const char *node, const char *path, const char *interface, const char *method, ...);
  extern SDL_bool SDL_DBus_CallVoidMethod(const char *node, const char *path, const char *interface, const char *method, ...);
  extern SDL_bool SDL_DBus_QueryProperty(const char *node, const char *path, const char *interface, const char *property, const int expectedtype, void *result);
  
  /* These use whatever connection you like. */
  extern SDL_bool SDL_DBus_CallMethodOnConnection(DBusConnection *conn, const char *node, const char *path, const char *interface, const char *method, ...);
  extern SDL_bool SDL_DBus_CallVoidMethodOnConnection(DBusConnection *conn, const char *node, const char *path, const char *interface, const char *method, ...);
  extern SDL_bool SDL_DBus_QueryPropertyOnConnection(DBusConnection *conn, const char *node, const char *path, const char *interface, const char *property, const int expectedtype, void *result);
  
  extern void SDL_DBus_ScreensaverTickle(void);
  extern SDL_bool SDL_DBus_ScreensaverInhibit(SDL_bool inhibit);
  
  #endif /* HAVE_DBUS_DBUS_H */
  
  #endif /* SDL_dbus_h_ */
  
  /* vi: set ts=4 sw=4 expandtab: */
  

Download