daemon: gather luacov statistics from early start

If KRESD_COVERAGE_STATS environment variable is set, luacov statistics
are saved to path specified by it.

Beware! Parallel execution needs special handling which is not built-in.

diff --git a/daemon/engine.c b/daemon/engine.c
index f126b855a522592c820f3a010f64922f51a29080..92fde30ae0c5bd07fd59c697162f8f70fde498fc 100644 (file)
--- a/daemon/engine.c
+++ b/daemon/engine.c
@@ -663,6 +663,34 @@ static void update_state(uv_timer_t *handle)
        lru_apply(engine->resolver.cache_rtt, update_stat_item, NULL);
 }
 
+/**
+ * Start luacov measurement and store results to file specified by
+ * KRESD_COVERAGE_STATS environment variable.
+ * Do nothing if the variable is not set.
+ */
+static void init_measurement(struct engine *engine)
+{
+       const char * const statspath = getenv("KRESD_COVERAGE_STATS");
+       if (!statspath)
+               return;
+
+       char * snippet = NULL;
+       int ret = asprintf(&snippet,
+               "_luacov_runner = require('luacov.runner')\n"
+               "_luacov_runner.init({\n"
+               "       statsfile = '%s',\n"
+               "       exclude = {'test', 'tapered', 'lua/5.1'},\n"
+               "})\n"
+               "jit.off()\n", statspath
+       );
+       assert(ret > 0);
+
+       ret = luaL_loadstring(engine->L, snippet);
+       assert(ret == 0);
+       lua_call(engine->L, 0, 0);
+       free(snippet);
+}
+
 int engine_init(struct engine *engine, knot_mm_t *pool)
 {
        if (engine == NULL) {
@@ -677,6 +705,7 @@ int engine_init(struct engine *engine, knot_mm_t *pool)
        if (ret != 0) {
                engine_deinit(engine);
        }
+       init_measurement(engine);
        /* Initialize resolver */
        ret = init_resolver(engine);
        if (ret != 0) {