mod_cron: Load last task run time inside task runner to fix async

This ensures that all interactions with storage happen inside an async
thread, allowing async waiting to be performed in storage drivers.

1 files changed, 28 insertions, 10 deletions

diff --git a/plugins/mod_cron.lua b/plugins/mod_cron.lua
index a39d05d5..dc9cfbd4 100644
--- a/plugins/mod_cron.lua
+++ b/plugins/mod_cron.lua
@@ -12,16 +12,27 @@ function module.add_host(host_module)
 	local last_run_times = host_module:open_store("cron", "map");
 	active_hosts[host_module.host] = true;
 
-	local function save_task(task, started_at) last_run_times:set(nil, task.id, started_at); end
+	local function save_task(task, started_at)
+		last_run_times:set(nil, task.id, started_at);
+	end
+
+	local function restore_task(task)
+		if task.last == nil then
+			task.last = last_run_times:get(nil, task.id);
+		end
+	end
 
 	local function task_added(event)
 		local task = event.item;
-		if task.name == nil then task.name = task.when; end
-		if task.id == nil then task.id = event.source.name .. "/" .. task.name:gsub("%W", "_"):lower(); end
-		if task.last == nil then task.last = last_run_times:get(nil, task.id); end
+		if task.name == nil then
+			task.name = task.when;
+		end
+		if task.id == nil then
+			task.id = event.source.name .. "/" .. task.name:gsub("%W", "_"):lower();
+		end
+		task.restore = restore_task;
 		task.save = save_task;
-		module:log("debug", "%s task %s added, last run %s", task.when, task.id,
-			task.last and datetime.datetime(task.last) or "never");
+		module:log("debug", "%s task %s added", task.when, task.id);
 		return true
 	end
 
@@ -33,12 +44,20 @@ function module.add_host(host_module)
 
 	host_module:handle_items("task", task_added, task_removed, true);
 
-	function host_module.unload() active_hosts[host_module.host] = nil; end
+	function host_module.unload()
+		active_hosts[host_module.host] = nil;
+	end
 end
 
-local function should_run(when, last) return not last or last + periods[when] * 0.995 <= os.time() end
+local function should_run(when, last)
+	return not last or last + periods[when] * 0.995 <= os.time()
+end
 
 local function run_task(task)
+	task:restore();
+	if not should_run(task.when, task.last) then
+		return
+	end
 	local started_at = os.time();
 	task:run(started_at);
 	task.last = started_at;
@@ -52,8 +71,7 @@ scheduled = module:add_timer(1, function()
 	for host in pairs(active_hosts) do
 		module:log("debug", "Running periodic tasks for host %s", host);
 		for _, task in ipairs(module:context(host):get_host_items("task")) do
-			module:log("debug", "Considering %s task %s (%s)", task.when, task.id, task.run);
-			if should_run(task.when, task.last) then task_runner:run(task); end
+			task_runner:run(task);
 		end
 	end
 	module:log("debug", "Wait %ds", delay);