From 98e95de90e79c581d2296084ea23919ed616ad29 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C5=99emysl=20Eric=20Janouch?= <p@janouch.name>
Date: Tue, 20 Oct 2020 02:02:09 +0200
Subject: [PATCH] degesch: add a hidden LOMEM compile option

---
 degesch.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/degesch.c b/degesch.c
index 6d120c2..d96567f 100644
--- a/degesch.c
+++ b/degesch.c
@@ -1904,6 +1904,8 @@ struct plugin
 
 struct plugin_vtable
 {
+	/// Collect garbage
+	void (*gc) (struct plugin *self);
 	/// Unregister and free the plugin including all relevant resources
 	void (*free) (struct plugin *self);
 };
@@ -5382,6 +5384,9 @@ transport_tls_init_ctx (struct server *s, SSL_CTX *ssl_ctx, struct error **e)
 #ifdef SSL_OP_NO_COMPRESSION
 	SSL_CTX_set_options (ssl_ctx, SSL_OP_NO_COMPRESSION);
 #endif // SSL_OP_NO_COMPRESSION
+#ifdef LOMEM
+	SSL_CTX_set_mode (ssl_ctx, SSL_MODE_RELEASE_BUFFERS);
+#endif // LOMEM
 
 	struct error *error = NULL;
 	if (!transport_tls_init_ca (s, ssl_ctx, &error))
@@ -8437,6 +8442,13 @@ struct lua_plugin
 	struct lua_schema_item *schemas;    ///< Registered schema items
 };
 
+static void
+lua_plugin_gc (struct plugin *self_)
+{
+	struct lua_plugin *self = (struct lua_plugin *) self_;
+	lua_gc (self->L, LUA_GCCOLLECT);
+}
+
 static void
 lua_plugin_free (struct plugin *self_)
 {
@@ -8446,6 +8458,7 @@ lua_plugin_free (struct plugin *self_)
 
 struct plugin_vtable lua_plugin_vtable =
 {
+	.gc   = lua_plugin_gc,
 	.free = lua_plugin_free,
 };
 
@@ -13821,7 +13834,14 @@ on_flush_timer (struct app_context *ctx)
 			"Log write failure detected for #s", buffer->name);
 	}
 
-	// TODO: maybe also garbage collect all plugins?
+#ifdef LOMEM
+	// Lua should normally be reasonable and collect garbage when needed,
+	// though we can try to push it.  This is a reasonable place.
+	LIST_FOR_EACH (struct plugin, iter, ctx->plugins)
+		if (iter->vtable->gc)
+			iter->vtable->gc (iter);
+#endif // LOMEM
+
 	rearm_flush_timer (ctx);
 }