From: Francis Deslauriers <francis.deslauriers@efficios.com>
Date: Mon, 27 Apr 2020 21:21:25 +0000 (-0400)
Subject: Generalize `lttng_enabler_link_bytecode()` bytecode list
X-Git-Tag: v2.13.0-rc1~436
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=621c07fc1b90c12ec997d539770da1937d11c450;p=lttng-ust.git

Generalize `lttng_enabler_link_bytecode()` bytecode list

So it can be used for both filter and capture bytecode runtimes

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I61ac07545f8db2964f8ea0a7d40ec7be306efe90
---

diff --git a/liblttng-ust/lttng-bytecode.c b/liblttng-ust/lttng-bytecode.c
index a05117a1..a6527ff1 100644
--- a/liblttng-ust/lttng-bytecode.c
+++ b/liblttng-ust/lttng-bytecode.c
@@ -519,31 +519,43 @@ void lttng_bytecode_filter_sync_state(struct lttng_bytecode_runtime *runtime)
 }
 
 /*
- * Link all bytecodes of the enabler referenced in the provided bytecode list.
+ * Given the lists of bytecode programs of an instance (trigger or event) and
+ * of a matching enabler, try to link all the enabler's bytecode programs with
+ * the instance.
+ *
+ * This function is called after we confirmed that name enabler and the
+ * instance are name matching (or glob pattern matching).
  */
 void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
 		struct lttng_ctx **ctx,
-		struct cds_list_head *bytecode_runtime_head,
-		struct lttng_enabler *enabler)
+		struct cds_list_head *instance_bytecode_head,
+		struct cds_list_head *enabler_bytecode_head)
 {
-	struct lttng_ust_bytecode_node *bc;
+	struct lttng_ust_bytecode_node *enabler_bc;
 	struct lttng_bytecode_runtime *runtime;
 
 	assert(event_desc);
 
-	/* Link each bytecode. */
-	cds_list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
+	/* Go over all the bytecode programs of the enabler. */
+	cds_list_for_each_entry(enabler_bc, enabler_bytecode_head, node) {
 		int found = 0, ret;
 		struct cds_list_head *insert_loc;
 
-		cds_list_for_each_entry(runtime,
-				bytecode_runtime_head, node) {
-			if (runtime->bc == bc) {
+		/*
+		 * Check if the current enabler bytecode program is already
+		 * linked with the instance.
+		 */
+		cds_list_for_each_entry(runtime, instance_bytecode_head, node) {
+			if (runtime->bc == enabler_bc) {
 				found = 1;
 				break;
 			}
 		}
-		/* Skip bytecode already linked */
+
+		/*
+		 * Skip bytecode already linked, go to the next enabler
+		 * bytecode program.
+		 */
 		if (found)
 			continue;
 
@@ -553,8 +565,8 @@ void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
 		 * insert the new bytecode right after it.
 		 */
 		cds_list_for_each_entry_reverse(runtime,
-				bytecode_runtime_head, node) {
-			if (runtime->bc->bc.seqnum <= bc->bc.seqnum) {
+				instance_bytecode_head, node) {
+			if (runtime->bc->bc.seqnum <= enabler_bc->bc.seqnum) {
 				/* insert here */
 				insert_loc = &runtime->node;
 				goto add_within;
@@ -562,10 +574,10 @@ void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
 		}
 
 		/* Add to head to list */
-		insert_loc = bytecode_runtime_head;
+		insert_loc = instance_bytecode_head;
 	add_within:
 		dbg_printf("linking bytecode\n");
-		ret = link_bytecode(event_desc, ctx, bc, insert_loc);
+		ret = link_bytecode(event_desc, ctx, enabler_bc, insert_loc);
 		if (ret) {
 			dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
 		}
diff --git a/liblttng-ust/lttng-events.c b/liblttng-ust/lttng-events.c
index d6d0642d..5941365a 100644
--- a/liblttng-ust/lttng-events.c
+++ b/liblttng-ust/lttng-events.c
@@ -1223,7 +1223,7 @@ int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
 		lttng_enabler_link_bytecode(event->desc,
 			&session->ctx,
 			&event->filter_bytecode_runtime_head,
-			lttng_event_enabler_as_enabler(event_enabler));
+			&lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
 
 		/* TODO: merge event context. */
 	}
@@ -1755,8 +1755,9 @@ int lttng_event_notifier_enabler_ref_event_notifiers(
 		 * Link filter bytecodes if not linked yet.
 		 */
 		lttng_enabler_link_bytecode(event_notifier->desc,
-			&event_notifier_group->ctx, &event_notifier->filter_bytecode_runtime_head,
-			lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
+			&event_notifier_group->ctx,
+			&event_notifier->filter_bytecode_runtime_head,
+			&lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
 	}
 end:
 	return 0;
diff --git a/liblttng-ust/ust-events-internal.h b/liblttng-ust/ust-events-internal.h
index 24393936..0fc0b795 100644
--- a/liblttng-ust/ust-events-internal.h
+++ b/liblttng-ust/ust-events-internal.h
@@ -150,16 +150,16 @@ int lttng_event_enabler_attach_exclusion(struct lttng_event_enabler *enabler,
 		struct lttng_ust_excluder_node *excluder);
 
 /*
- * Synchronize bytecodes for the enabler and the event.
+ * Synchronize bytecodes for the enabler and the instance (event or trigger).
  *
- * This function goes over all bytecode programs of the event enabler to ensure
- * each is linked to the provided event.
+ * This function goes over all bytecode programs of the enabler (event or
+ * trigger enabler) to ensure each is linked to the provided instance.
  */
 LTTNG_HIDDEN
 void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
 		struct lttng_ctx **ctx,
-		struct cds_list_head *bytecode_runtime_head,
-		struct lttng_enabler *enabler);
+		struct cds_list_head *instance_bytecode_runtime_head,
+		struct cds_list_head *enabler_bytecode_runtime_head);
 
 /*
  * Allocate and initialize a `struct lttng_event_notifier_group` object.