From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Fri, 18 Mar 2016 19:52:18 +0000 (-0400)
Subject: Implement variant type
X-Git-Tag: v2.9.0-rc1~76
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=65c85aa61984217039857513bbe988036f371693;p=lttng-modules.git

Implement variant type

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/lttng-context.c b/lttng-context.c
index 93373226..d299d5e2 100644
--- a/lttng-context.c
+++ b/lttng-context.c
@@ -144,6 +144,7 @@ void lttng_context_update(struct lttng_ctx *ctx)
 			case atype_struct:
 			case atype_array_compound:
 			case atype_sequence_compound:
+			case atype_variant:
 			default:
 				WARN_ON_ONCE(1);
 				break;
@@ -166,6 +167,7 @@ void lttng_context_update(struct lttng_ctx *ctx)
 			case atype_struct:
 			case atype_array_compound:
 			case atype_sequence_compound:
+			case atype_variant:
 			default:
 				WARN_ON_ONCE(1);
 				break;
@@ -187,6 +189,7 @@ void lttng_context_update(struct lttng_ctx *ctx)
 			case atype_struct:
 			case atype_array_compound:
 			case atype_sequence_compound:
+			case atype_variant:
 			default:
 				WARN_ON_ONCE(1);
 				break;
@@ -199,6 +202,7 @@ void lttng_context_update(struct lttng_ctx *ctx)
 		case atype_struct:
 		case atype_array_compound:
 		case atype_sequence_compound:
+		case atype_variant:
 			break;
 
 		case atype_enum:
diff --git a/lttng-events.c b/lttng-events.c
index a5fe3e86..0c72015f 100644
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -1736,6 +1736,62 @@ int _lttng_struct_statedump(struct lttng_session *session,
 	return ret;
 }
 
+/*
+ * Must be called with sessions_mutex held.
+ */
+static
+int _lttng_variant_type_statedump(struct lttng_session *session,
+		const struct lttng_type *type,
+		size_t nesting)
+{
+	int ret;
+	uint32_t i, nr_choices;
+
+	ret = print_tabs(session, nesting);
+	if (ret)
+		return ret;
+	ret = lttng_metadata_printf(session,
+		"variant <_%s> {\n",
+		type->u.variant.tag_name);
+	if (ret)
+		return ret;
+	nr_choices = type->u.variant.nr_choices;
+	for (i = 0; i < nr_choices; i++) {
+		const struct lttng_event_field *iter_field;
+
+		iter_field = &type->u.variant.choices[i];
+		ret = _lttng_field_statedump(session, iter_field, nesting + 1);
+		if (ret)
+			return ret;
+	}
+	ret = print_tabs(session, nesting);
+	if (ret)
+		return ret;
+	ret = lttng_metadata_printf(session,
+		"}");
+	return ret;
+}
+
+/*
+ * Must be called with sessions_mutex held.
+ */
+static
+int _lttng_variant_statedump(struct lttng_session *session,
+		const struct lttng_event_field *field,
+		size_t nesting)
+{
+	int ret;
+
+	ret = _lttng_variant_type_statedump(session,
+			&field->type, nesting);
+	if (ret)
+		return ret;
+	ret = lttng_metadata_printf(session,
+		"_%s;\n",
+		field->name);
+	return ret;
+}
+
 /*
  * Must be called with sessions_mutex held.
  */
@@ -1747,7 +1803,7 @@ int _lttng_array_compound_statedump(struct lttng_session *session,
 	int ret;
 	const struct lttng_type *elem_type;
 
-	/* Only array of structures are currently supported. */
+	/* Only array of structures and variants are currently supported. */
 	elem_type = field->type.u.array_compound.elem_type;
 	switch (elem_type->atype) {
 	case atype_struct:
@@ -1755,6 +1811,11 @@ int _lttng_array_compound_statedump(struct lttng_session *session,
 		if (ret)
 			return ret;
 		break;
+	case atype_variant:
+		ret = _lttng_variant_type_statedump(session, elem_type, nesting);
+		if (ret)
+			return ret;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -1779,7 +1840,7 @@ int _lttng_sequence_compound_statedump(struct lttng_session *session,
 
 	length_name = field->type.u.sequence_compound.length_name;
 
-	/* Only array of structures are currently supported. */
+	/* Only array of structures and variants are currently supported. */
 	elem_type = field->type.u.sequence_compound.elem_type;
 	switch (elem_type->atype) {
 	case atype_struct:
@@ -1787,6 +1848,11 @@ int _lttng_sequence_compound_statedump(struct lttng_session *session,
 		if (ret)
 			return ret;
 		break;
+	case atype_variant:
+		ret = _lttng_variant_type_statedump(session, elem_type, nesting);
+		if (ret)
+			return ret;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -1962,6 +2028,9 @@ int _lttng_field_statedump(struct lttng_session *session,
 	case atype_sequence_compound:
 		ret = _lttng_sequence_compound_statedump(session, field, nesting);
 		break;
+	case atype_variant:
+		ret = _lttng_variant_statedump(session, field, nesting);
+		break;
 
 	default:
 		WARN_ON_ONCE(1);
diff --git a/lttng-events.h b/lttng-events.h
index 56f5d3ac..9d775d57 100644
--- a/lttng-events.h
+++ b/lttng-events.h
@@ -52,6 +52,7 @@ enum abstract_types {
 	atype_struct,
 	atype_array_compound,		/* Array of compound types. */
 	atype_sequence_compound,	/* Sequence of compound types. */
+	atype_variant,
 	NR_ABSTRACT_TYPES,
 };
 
@@ -139,6 +140,11 @@ struct lttng_type {
 			struct lttng_type *elem_type;
 			const char *length_name;
 		} sequence_compound;
+		struct {
+			const char *tag_name;
+			struct lttng_event_field *choices; /* Array of fields. */
+			uint32_t nr_choices;
+		} variant;
 	} u;
 };
 
diff --git a/lttng-filter.c b/lttng-filter.c
index 96ba1d23..36c6db90 100644
--- a/lttng-filter.c
+++ b/lttng-filter.c
@@ -186,6 +186,7 @@ int apply_field_reloc(struct lttng_event *event,
 		case atype_struct:		/* Unsupported. */
 		case atype_array_compound:	/* Unsupported. */
 		case atype_sequence_compound:	/* Unsupported. */
+		case atype_variant:		/* Unsupported. */
 		default:
 			return -EINVAL;
 		}
@@ -221,6 +222,7 @@ int apply_field_reloc(struct lttng_event *event,
 	case atype_struct:		/* Unsupported. */
 	case atype_array_compound:	/* Unsupported. */
 	case atype_sequence_compound:	/* Unsupported. */
+	case atype_variant:		/* Unsupported. */
 	default:
 		return -EINVAL;
 	}
@@ -271,6 +273,7 @@ int apply_context_reloc(struct lttng_event *event,
 	case atype_struct:	/* Unsupported. */
 	case atype_array_compound:	/* Unsupported. */
 	case atype_sequence_compound:	/* Unsupported. */
+	case atype_variant:		/* Unsupported. */
 	default:
 		return -EINVAL;
 	}