asyncio: Added Linux io_uring support.

CMakeLists.txt

@@ -286,6 +286,7 @@ set_option(SDL_SYSTEM_ICONV        "Use iconv() from system-installed libraries"
 set_option(SDL_LIBICONV            "Prefer iconv() from libiconv, if available, over libc version" OFF)
 set_option(SDL_GCC_ATOMICS         "Use gcc builtin atomics" ${SDL_GCC_ATOMICS_DEFAULT})
 dep_option(SDL_DBUS                "Enable D-Bus support" ON "${UNIX_SYS}" OFF)
+dep_option(SDL_LIBURING            "Enable liburing support" ON "${UNIX_SYS}" OFF)
 dep_option(SDL_DISKAUDIO           "Support the disk writer audio driver" ON "SDL_AUDIO" OFF)
 dep_option(SDL_DUMMYAUDIO          "Support the dummy audio driver" ON "SDL_AUDIO" OFF)
 dep_option(SDL_DUMMYVIDEO          "Use dummy video driver" ON "SDL_VIDEO" OFF)
@@ -1657,6 +1658,16 @@ elseif(UNIX AND NOT APPLE AND NOT RISCOS AND NOT HAIKU)
         set(SDL_USE_IME 1)
       endif()
 
+      if(SDL_LIBURING)
+        pkg_search_module(LIBURING liburing-ffi)
+        find_path(HAVE_LIBURING_H NAMES liburing.h)
+        if(LIBURING_FOUND AND HAVE_LIBURING_H)
+          set(HAVE_LIBURING_LIBURING_H TRUE)
+          sdl_include_directories(PRIVATE SYSTEM ${LIBURING_INCLUDE_DIRS})
+          set(HAVE_LIBURING TRUE)
+        endif()
+      endif()
+
       if((FREEBSD OR NETBSD) AND NOT HAVE_INOTIFY)
         set(LibInotify_PKG_CONFIG_SPEC libinotify)
         pkg_check_modules(PC_LIBINOTIFY IMPORTED_TARGET ${LibInotify_PKG_CONFIG_SPEC})
@@ -1720,6 +1731,10 @@ elseif(UNIX AND NOT APPLE AND NOT RISCOS AND NOT HAIKU)
       endif()
     endif()
 
+    if(HAVE_LIBURING_H)
+      sdl_sources("${SDL3_SOURCE_DIR}/src/file/io_uring/SDL_asyncio_liburing.c")
+    endif()
+
     # Always compiled for Linux, unconditionally:
     sdl_sources(
       "${SDL3_SOURCE_DIR}/src/core/linux/SDL_evdev_capabilities.c"