unit: properly update references to units which are merged

When we merge units that some kind of object points to, those pointers
might become invalidated, and needs to be updated. Introduce a UnitRef
struct which links up all the unit references, to ensure corrected
references.

At the same time, drop configured_sockets in the Service object, and
replace it by proper UNIT_TRIGGERS resp. UNIT_TRIGGERED_BY dependencies,
which allow us to simplify a lot of code.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/service.h b/src/service.h
index 2102826723..8f67ad50a8 100644
--- a/src/service.h
+++ b/src/service.h
@@ -27,6 +27,7 @@ typedef struct Service Service;
 #include "unit.h"
 #include "path.h"
 #include "ratelimit.h"
+#include "service.h"
 
 typedef enum ServiceState {
         SERVICE_DEAD,
@@ -154,8 +155,7 @@ struct Service {
 
         RateLimit ratelimit;
 
-        struct Socket *accept_socket;
-        Set *configured_sockets;
+        UnitRef accept_socket;
 
         Watch timer_watch;
         PathSpec *pid_file_pathspec;
@@ -165,6 +165,8 @@ struct Service {
 
 extern const UnitVTable service_vtable;
 
+struct Socket;
+
 int service_set_socket_fd(Service *s, int fd, struct Socket *socket);
 
 const char* service_state_to_string(ServiceState i);