2 files changed, 34 insertions, 28 deletions

diff --git a/src/libserver/symcache/symcache_runtime.cxx b/src/libserver/symcache/symcache_runtime.cxx
index 15f970d8c..741e75183 100644
--- a/src/libserver/symcache/symcache_runtime.cxx
+++ b/src/libserver/symcache/symcache_runtime.cxx
@@ -1,5 +1,5 @@
 /*
- * Copyright 2023 Vsevolod Stakhov
+ * Copyright 2024 Vsevolod Stakhov
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -51,6 +51,12 @@ auto symcache_runtime::create(struct rspamd_task *task, symcache &cache) -> symc
 	checkpoint->profile_start = now;
 	checkpoint->lim = rspamd_task_get_required_score(task, task->result);
 
+	/*
+	 * We enable profiling if the following conditions are met:
+	 * - we have not profiled for a long time
+	 * - message is large
+	 * - random probability
+	 */
 	if ((cache.get_last_profile() == 0.0 || now > cache.get_last_profile() + PROFILE_MAX_TIME) ||
 		(task->msg.len >= PROFILE_MESSAGE_SIZE_THRESHOLD) ||
 		(rspamd_random_double_fast() >= (1 - PROFILE_PROBABILITY))) {
@@ -332,10 +338,7 @@ auto symcache_runtime::process_pre_postfilters(struct rspamd_task *task,
 		auto dyn_item = get_dynamic_item(item->id);
 
 		if (!dyn_item->started && !dyn_item->finished) {
-			if (has_slow) {
-				/* Delay */
-				has_slow = false;
-
+			if (slow_status == slow_status::enabled) {
 				return false;
 			}
 
@@ -424,10 +427,7 @@ auto symcache_runtime::process_filters(struct rspamd_task *task, symcache &cache
 
 			process_symbol(task, cache, item.get(), dyn_item);
 
-			if (has_slow) {
-				/* Delay */
-				has_slow = false;
-
+			if (slow_status == slow_status::enabled) {
 				return false;
 			}
 		}
@@ -654,7 +654,7 @@ rspamd_symcache_delayed_item_cb(EV_P_ ev_timer *w, int what)
 	if (cbd->event) {
 		cbd->event = nullptr;
 
-		/* Timer will be stopped here */
+		/* Timer will be stopped here; `has_slow` is also reset there */
 		rspamd_session_remove_event(cbd->task->s,
 									rspamd_symcache_delayed_item_fin, cbd);
 
@@ -732,7 +732,7 @@ auto symcache_runtime::finalize_item(struct rspamd_task *task, cache_dynamic_ite
 		}
 		else {
 			/* Just reset as no timer is added */
-			has_slow = FALSE;
+			slow_status = slow_status::none;
 			return false;
 		}
 
@@ -744,34 +744,32 @@ auto symcache_runtime::finalize_item(struct rspamd_task *task, cache_dynamic_ite
 		auto diff = ((ev_now(task->event_loop) - profile_start) * 1e3 -
 					 dyn_item->start_msec);
 
+		if (G_UNLIKELY(RSPAMD_TASK_IS_PROFILING(task))) {
+			rspamd_task_profile_set(task, item->symbol.c_str(), diff);
+		}
+
+		if (rspamd_worker_is_scanner(task->worker)) {
+			rspamd_set_counter(item->cd, diff);
+		}
+
 		if (diff > slow_diff_limit) {
 
-			if (!has_slow) {
-				has_slow = true;
+			if (slow_status == slow_status::none) {
+				slow_status = slow_status::enabled;
 
-				msg_info_task("slow rule: %s(%d): %.2f ms; enable slow timer delay",
+				msg_info_task("slow rule: %s(%d): %.2f ms; enable 100ms idle timer to allow other rules to be finished",
 							  item->symbol.c_str(), item->id,
 							  diff);
-
 				if (enable_slow_timer()) {
-					/* Allow network execution */
 					return;
 				}
 			}
 			else {
-				msg_info_task("slow rule: %s(%d): %.2f ms",
+				msg_info_task("slow rule: %s(%d): %.2f ms; idle timer has already been activated for this scan",
 							  item->symbol.c_str(), item->id,
 							  diff);
 			}
 		}
-
-		if (G_UNLIKELY(RSPAMD_TASK_IS_PROFILING(task))) {
-			rspamd_task_profile_set(task, item->symbol.c_str(), diff);
-		}
-
-		if (rspamd_worker_is_scanner(task->worker)) {
-			rspamd_set_counter(item->cd, diff);
-		}
 	}
 
 	process_item_rdeps(task, item);
diff --git a/src/libserver/symcache/symcache_runtime.hxx b/src/libserver/symcache/symcache_runtime.hxx
index aa8f66c0f..181b32880 100644
--- a/src/libserver/symcache/symcache_runtime.hxx
+++ b/src/libserver/symcache/symcache_runtime.hxx
@@ -1,5 +1,5 @@
 /*
- * Copyright 2023 Vsevolod Stakhov
+ * Copyright 2024 Vsevolod Stakhov
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -46,10 +46,16 @@ struct cache_dynamic_item {
 static_assert(sizeof(cache_dynamic_item) == sizeof(std::uint64_t));
 static_assert(std::is_trivial_v<cache_dynamic_item>);
 
+
 class symcache_runtime {
 	unsigned items_inflight;
+	enum class slow_status : std::uint8_t {
+		none = 0,
+		enabled = 1,
+		disabled = 2,
+	} slow_status;
+
 	bool profile;
-	bool has_slow;
 
 	double profile_start;
 	double lim;
@@ -199,7 +205,9 @@ public:
 	/* XXX: a helper to allow hiding internal implementation of the slow timer structure */
 	auto unset_slow() -> void
 	{
-		has_slow = false;
+		if (slow_status == slow_status::enabled) {
+			slow_status = slow_status::disabled;
+		}
 	}
 };