add support for systemd event loop

Author: zishfish

CMakeLists-implied-options.txt

@@ -87,6 +87,7 @@ if(LWS_WITH_DISTRO_RECOMMENDED)
 	set(LWS_WITH_LIBUV 1)				# libuv
 	set(LWS_WITH_LIBEV 1)				# libev
 	set(LWS_WITH_LIBEVENT 1)			# libevent
+	set(LWS_WITH_SDEVENT 0)				# sd-event
 	set(LWS_WITH_EVLIB_PLUGINS 1)			# event libraries created as plugins / individual packages
 	set(LWS_WITHOUT_EXTENSIONS 0)			# libz
 	set(LWS_ROLE_DBUS 1)				# dbus-related libs
@@ -117,7 +118,8 @@ endif()
 if (LWS_WITH_LIBEV OR
     LWS_WITH_LIBUV OR
     LWS_WITH_LIBEVENT OR
-    LWS_WITH_GLIB)
+    LWS_WITH_GLIB OR
+    LWS_WITH_SDEVENT)
 	set(LWS_WITH_EVENT_LIBS 1)
 else()
 	unset(LWS_WITH_EVENT_LIBS)

CMakeLists.txt

@@ -152,6 +152,7 @@ option(LWS_WITH_LIBEV "Compile with support for libev" OFF)
 option(LWS_WITH_LIBUV "Compile with support for libuv" OFF)
 option(LWS_WITH_LIBEVENT "Compile with support for libevent" OFF)
 option(LWS_WITH_GLIB "Compile with support for glib event loop" OFF)
+option(LWS_WITH_SDEVENT "Compile with support for sd-event loop" OFF)
 
 if (UNIX)
 # since v4.1, on unix platforms default is build any event libs as runtime plugins

cmake/lws_config.h.in

@@ -150,6 +150,7 @@
 #cmakedefine LWS_WITH_LIBEV
 #cmakedefine LWS_WITH_LIBEVENT
 #cmakedefine LWS_WITH_LIBUV
+#cmakedefine LWS_WITH_SDEVENT
 #cmakedefine LWS_WITH_LWSAC
 #cmakedefine LWS_LOGS_TIMESTAMP
 #cmakedefine LWS_WITH_MBEDTLS

include/libwebsockets/lws-context-vhost.h

@@ -230,6 +230,9 @@
 	/**< (CTX) Disable lws_system state, eg, because we are a secure streams
 	 * proxy client that is not trying to track system state by itself. */
 
+#define LWS_SERVER_OPTION_SDEVENT			 (1ll << 36)
+    /**< (CTX) Use sd-event loop */
+
 	/****** add new things just above ---^ ******/
 
 

lib/core/context.c

@@ -340,6 +340,7 @@ static const struct lws_evlib_map {
 	{ LWS_SERVER_OPTION_LIBEVENT, "evlib_event" },
 	{ LWS_SERVER_OPTION_GLIB,     "evlib_glib" },
 	{ LWS_SERVER_OPTION_LIBEV,    "evlib_ev" },
+	{ LWS_SERVER_OPTION_SDEVENT,  "evlib_sd" },
 };
 static const char * const dlist[] = {
 	LWS_INSTALL_LIBDIR,
@@ -520,6 +521,13 @@ lws_create_context(const struct lws_context_creation_info *info)
 	}
 #endif
 
+#if defined(LWS_WITH_SDEVENT)
+    if (lws_check_opt(info->options, LWS_SERVER_OPTION_SDEVENT)) {
+        extern const lws_plugin_evlib_t evlib_sd;
+        plev = &evlib_sd;
+    }
+#endif
+
 #endif /* with event libs */
 
 #endif /* not with ev plugins */

lib/event-libs/CMakeLists.txt

@@ -91,6 +91,10 @@ if (LWS_WITH_LIBEV)
 	set(LWS_HAVE_EVBACKEND_IOURING ${LWS_HAVE_EVBACKEND_IOURING} PARENT_SCOPE)
 endif()
 
+if (LWS_WITH_SDEVENT)
+	add_subdir_include_directories(sdevent)
+endif()
+
 
 
 #

lib/event-libs/sdevent/CMakeLists.txt

@@ -0,0 +1,41 @@
+# The strategy is to only export to PARENT_SCOPE
+#
+#  - changes to LIB_LIST
+#  - includes via include_directories
+#
+# and keep everything else private
+
+include_directories(.)
+
+# configure or find systemd library
+set(LIB_SYSTEMD_LIBRARIES CACHE PATH "Path to the libsystemd library")
+if ("${LWS_SYSTEMD_LIBRARIES}" STREQUAL "")
+    if (NOT LIB_SYSTEMD_FOUND)
+        find_library(LIBSYSTEMD_LIBRARIES NAMES systemd)
+    endif()
+else()
+    set(LIBSYSTEMD_LIBRARIES ${LWS_SYSTEMD_LIBRARIES})
+endif()
+message("libsystemd libraries: ${LIBSYSTEMD_LIBRARIES}")
+
+if (LWS_WITH_EVLIB_PLUGINS)
+
+    create_evlib_plugin(
+            evlib_sd
+            sdevent.c
+            private-lib-event-libs-sdevent.h
+            ${LIBSYSTEMD_LIBRARIES}
+    )
+
+else()
+
+    list(APPEND LIB_LIST ${LIBSYSTEMD_LIBRARIES})
+    list(APPEND SOURCES event-libs/sdevent/sdevent.c)
+
+endif()
+
+#
+# Keep explicit parent scope exports at end
+#
+
+exports_to_parent_scope()

lib/event-libs/sdevent/private-lib-event-libs-sdevent.h

@@ -0,0 +1,3 @@
+#include <private-lib-core.h>
+
+extern const struct lws_event_loop_ops event_loop_ops_sdevent;