+
+/**
+ * Internal callback for evmgr management.
+ * The effect of this function is hidden: it exits
+ * the waiting poll if any.
+ */
+static void evmgr_on_efd_event(struct evmgr *evmgr)
+{
+ uint64_t x;
+ read(evmgr->efd, &x, sizeof x);
+}
+
+/**
+ * wakeup the event loop if needed by sending
+ * an event.
+ */
+void evmgr_wakeup(struct evmgr *evmgr)
+{
+ uint64_t x;
+
+ if (evmgr->state & EVLOOP_STATE_WAIT) {
+ x = 1;
+ write(evmgr->efd, &x, sizeof x);
+ }
+}
+
+/**
+ */
+void *evmgr_holder(struct evmgr *evmgr)
+{
+ return evmgr->holder;
+}
+
+/**
+ */
+int evmgr_release_if(struct evmgr *evmgr, void *holder)
+{
+ if (evmgr->holder != holder)
+ return 0;
+ evmgr->holder = 0;
+ return 1;
+}
+
+/**
+ */
+int evmgr_try_hold(struct evmgr *evmgr, void *holder)
+{
+ if (!evmgr->holder)
+ evmgr->holder = holder;
+ return evmgr->holder == holder;
+}
+
+/******************************************************************************/
+/******************************************************************************/
+/****** SYSTEM D ******/
+/******************************************************************************/
+/******************************************************************************/
+
+#if WITH_SYSTEMD
+