From a46879eefd9563015cd6ef88465fef9ecc833054 Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonyg@leastfixedpoint.com>
Date: Mon, 27 Sep 2021 13:19:36 +0200
Subject: [PATCH] TODO

---
 TODO.md | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 TODO.md

diff --git a/TODO.md b/TODO.md
new file mode 100644
index 0000000..f87420e
--- /dev/null
+++ b/TODO.md
@@ -0,0 +1,55 @@
+ - signals (SIGTERM)
+
+ - service-started, service-running, and service-complete
+    - actually more like: stopped, starting, started, running, failed, and stopping.
+    - ... but with `complete` added, to mirror `failed`.
+    - service controls: reload?, restart, pause, unpause, force-stop ("blocked")
+    - difference between "pause" and "block" is that "pause" stops the
+      actual program instance but doesn't flag the service as
+      non-started, while "block" pushes it all the way back to
+      "stopped".
+
+ - deal with logging
+    - when syslogd is running, /dev/log is a unix datagram socket
+
+ - service for `apk` operations - otherwise they clash
+
+Service lifecycle (as freely imagined; really, a state machine similar
+to this will be induced by assertion-driven
+subconversations/facets...):
+
+    digraph G {
+        compound=true;
+
+        subgraph cluster_runnable {
+            label="Runnable";
+            running [label="running\n(a.k.a. ready)"];
+            starting -> started [label="deps satisfied\nstart svc"];
+            started -> running [label="marked running\n-"];
+            started -> failed [label="start failed\n-"];
+            started -> complete [label="svc done\n-"];
+            running -> failed [label="svc failed\n-"];
+            running -> complete [label="svc done\n-"];
+            failed -> started [label="restart\nstart svc"];
+            complete -> started [label="restart\nstart svc"];
+            running -> started [label="restart\nstart svc"];
+        }
+        stopped;
+        paused [label="running\n(paused)"];
+        blocked [label="stopped\n(blocked)"];
+
+        stopped -> starting [label="required\nscan deps"];
+        running -> stopped [label="unrequired\nstop svc"];
+
+        running -> paused [lhead=cluster_runnable, label="pause req\nstop svc"];
+        paused -> starting [label="unpause req\nscan deps"];
+
+        running -> blocked [lhead=cluster_runnable, label="block req\nstop svc"];
+        blocked -> stopped [label="unblock req\ncheck for requirement"];
+
+        paused -> blocked [label="block req\n-"];
+    }
+
+Oh, how about having a set-of-states approach: one for the
+supervision/dependency-resolution process, and one for the service
+itself?