Measure how long an app changing module cannot answer, against a host restart (030)

An app of a million items (a list grown by doubling) or of a thousand, in
a host of apps, its store in RAM: the longest gap between two answered
writes while it changes module on SIGHUP (stopped and started again from
its store, 71e319b), and while the host is restarted. A thousand items:
1.59 ms against 3.05 (median of 20 and 10). A million: 150.64 ms against
149.73 (10 and 5): both are the store read again (pure_app_start, 142
ms), so changing does not answer sooner than restarting.

1 files changed, 28 insertions, 0 deletions

diff --git a/research/experiments/030-app-lifecycle/items.aup b/research/experiments/030-app-lifecycle/items.aup
new file mode 100644
index 0000000..b6d928b
--- /dev/null
+++ b/research/experiments/030-app-lifecycle/items.aup
@@ -0,0 +1,28 @@
+record Item {
+  n = 0
+}
+state items: list of Item
+state more: list of Item
+state hits = 0
+input seed = message { n: number }
+input grow = message { step: number }
+input add = message { step: number }
+on seed {
+  items.append(Item { n: seed.n })
+}
+on grow {
+  for i in items {
+    more.append(Item { n: i.n + grow.step })
+  }
+  for m in more {
+    items.append(Item { n: m.n })
+  }
+  for m in more {
+    more.remove(m)
+  }
+}
+on add {
+  hits = hits + add.step
+}
+view count = count(i in items where i.n > 0)
+view total = hits