reaper: SIGHUP calls Lua function "reload"

CM4all · Dec 6, 2023 · 0557ac9 · 0557ac9
1 parent 41a6ce1
commit 0557ac9
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Showing 5 changed files with 19 additions and 1 deletion.
diff --git a/debian/changelog b/debian/changelog
@@ -2,6 +2,7 @@ cm4all-spawn (0.15) unstable; urgency=low
 
   * reaper: refactor the Lua cgroup API
   * reaper: add Lua attribute for inspecting a cgroup's parent
+  * reaper: SIGHUP calls Lua function "reload"
   * systemd: remove dependency on "network.target"
 
  --   

diff --git a/doc/index.rst b/doc/index.rst
@@ -29,6 +29,14 @@ This daemon watches cgroups below certain scopes; once they run empty,
 statistics are collected and logged and the cgroup is deleted.
 
 
+``SIGHUP``
+^^^^^^^^^^
+
+On ``systemctl reload cm4all-spawn-reaper`` (i.e. ``SIGHUP``), the
+daemon calls the Lua function ``reload`` if one was defined.  It is up
+to the Lua script to define the exact meaning of this feature.
+
+
 Resource Accounting
 ^^^^^^^^^^^^^^^^^^^
 

diff --git a/libcommon b/libcommon
diff --git a/src/reaper/Instance.cxx b/src/reaper/Instance.cxx
@@ -99,4 +99,6 @@ Instance::OnExit() noexcept
 void
 Instance::OnReload(int) noexcept
 {
+	if (lua_accounting)
+		lua_accounting->Reload();
 }
diff --git a/src/reaper/LAccounting.hxx b/src/reaper/LAccounting.hxx
@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include "lua/ReloadRunner.hxx"
 #include "lua/State.hxx"
 #include "lua/ValuePtr.hxx"
 #include "util/IntrusiveList.hxx"
@@ -14,6 +15,8 @@ struct CgroupResourceUsage;
 class LuaAccounting final {
 	Lua::State state;
 
+	Lua::ReloadRunner reload{state.get()};
+
 	const Lua::ValuePtr handler;
 
 	class Thread;
@@ -25,6 +28,10 @@ public:
 
 	~LuaAccounting() noexcept;
 
+	void Reload() noexcept {
+		reload.Start();
+	}
+
 	void InvokeCgroupReleased(UniqueFileDescriptor cgroup_fd,
 				  const char *relative_path,
 				  const CgroupResourceUsage &usage);
+69 −0		src/lua/ReloadRunner.cxx
+37 −0		src/lua/ReloadRunner.hxx
+1 −0		src/lua/meson.build
+7 −10		src/lua/pg/Connection.cxx