X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=blobdiff_plain;f=lib%2Fctf-ir%2Fevent.c;h=5cfd5e14a124515e8bbcfc943722c71c8b75e005;hp=6dc7ad0754c4dd0da7bd7d3992983eb8a803f766;hb=312c056ae3d374b253fa0cfe5ed576c0b0e5e569;hpb=50842bdc4c21f3de2b63e29cdac730af8b6dcca6

diff --git a/lib/ctf-ir/event.c b/lib/ctf-ir/event.c
index 6dc7ad07..5cfd5e14 100644
--- a/lib/ctf-ir/event.c
+++ b/lib/ctf-ir/event.c
@@ -29,6 +29,7 @@
 #define BT_LOG_TAG "EVENT"
 #include <babeltrace/lib-logging-internal.h>
 
+#include <babeltrace/assert-pre-internal.h>
 #include <babeltrace/ctf-ir/fields-internal.h>
 #include <babeltrace/ctf-ir/field-types-internal.h>
 #include <babeltrace/ctf-ir/clock-class.h>
@@ -43,95 +44,68 @@
 #include <babeltrace/ctf-ir/stream-internal.h>
 #include <babeltrace/ctf-ir/packet.h>
 #include <babeltrace/ctf-ir/packet-internal.h>
+#include <babeltrace/ctf-ir/trace.h>
 #include <babeltrace/ctf-ir/trace-internal.h>
 #include <babeltrace/ctf-ir/validation-internal.h>
 #include <babeltrace/ctf-ir/packet-internal.h>
 #include <babeltrace/ctf-ir/utils.h>
-#include <babeltrace/ctf-writer/serialize-internal.h>
 #include <babeltrace/ref.h>
 #include <babeltrace/ctf-ir/attributes-internal.h>
 #include <babeltrace/compiler-internal.h>
+#include <babeltrace/assert-internal.h>
 #include <inttypes.h>
 
 static
-void bt_event_destroy(struct bt_object *obj);
-
-struct bt_event *bt_event_create(struct bt_event_class *event_class)
+int bt_event_common_validate_types_for_create(
+		struct bt_event_class_common *event_class,
+		struct bt_validation_output *validation_output,
+		bt_validation_flag_copy_field_type_func copy_field_type_func)
 {
 	int ret;
 	enum bt_validation_flag validation_flags =
 		BT_VALIDATION_FLAG_STREAM |
 		BT_VALIDATION_FLAG_EVENT;
-	struct bt_event *event = NULL;
-	struct bt_trace *trace = NULL;
-	struct bt_stream_class *stream_class = NULL;
-	struct bt_field_type *packet_header_type = NULL;
-	struct bt_field_type *packet_context_type = NULL;
-	struct bt_field_type *event_header_type = NULL;
-	struct bt_field_type *stream_event_ctx_type = NULL;
-	struct bt_field_type *event_context_type = NULL;
-	struct bt_field_type *event_payload_type = NULL;
-	struct bt_field *event_header = NULL;
-	struct bt_field *stream_event_context = NULL;
-	struct bt_field *event_context = NULL;
-	struct bt_field *event_payload = NULL;
-	struct bt_value *environment = NULL;
-	struct bt_validation_output validation_output = { 0 };
+	struct bt_trace_common *trace = NULL;
+	struct bt_stream_class_common *stream_class = NULL;
+	struct bt_field_type_common *packet_header_type = NULL;
+	struct bt_field_type_common *packet_context_type = NULL;
+	struct bt_field_type_common *event_header_type = NULL;
+	struct bt_field_type_common *stream_event_ctx_type = NULL;
+	struct bt_field_type_common *event_context_type = NULL;
+	struct bt_field_type_common *event_payload_type = NULL;
 	int trace_valid = 0;
+	struct bt_value *environment = NULL;
 
-	BT_LOGD("Creating event object: event-class-addr=%p, "
-		"event-class-name=\"%s\", event-class-id=%" PRId64,
-		event_class, bt_event_class_get_name(event_class),
-		bt_event_class_get_id(event_class));
-
-	if (!event_class) {
-		BT_LOGW_STR("Invalid parameter: event class is NULL.");
-		goto error;
-	}
-
-	stream_class = bt_event_class_get_stream_class(event_class);
-
-	/*
-	 * We disallow the creation of an event if its event class has not been
-	 * associated to a stream class.
-	 */
-	if (!stream_class) {
-		BT_LOGW_STR("Event class is not part of a stream class.");
-		goto error;
-	}
-
-	/* The event class was frozen when added to its stream class */
-	assert(event_class->frozen);
-
-	/* Validate the trace (if any), the stream class, and the event class */
-	trace = bt_stream_class_get_trace(stream_class);
+	stream_class = bt_event_class_common_borrow_stream_class(event_class);
+	BT_ASSERT(stream_class);
+	trace = bt_stream_class_common_borrow_trace(stream_class);
 	if (trace) {
-		BT_LOGD_STR("Event's class is part of a trace.");
-		packet_header_type = bt_trace_get_packet_header_type(trace);
+		BT_LOGD_STR("Event class is part of a trace.");
+		packet_header_type =
+			bt_trace_common_borrow_packet_header_field_type(trace);
 		trace_valid = trace->valid;
-		assert(trace_valid);
+		BT_ASSERT(trace_valid);
 		environment = trace->environment;
 	}
 
-	packet_context_type = bt_stream_class_get_packet_context_type(
-		stream_class);
-	event_header_type = bt_stream_class_get_event_header_type(
-		stream_class);
-	stream_event_ctx_type = bt_stream_class_get_event_context_type(
-		stream_class);
-	event_context_type = bt_event_class_get_context_type(event_class);
-	event_payload_type = bt_event_class_get_payload_type(event_class);
+	packet_context_type =
+		bt_stream_class_common_borrow_packet_context_field_type(
+			stream_class);
+	event_header_type =
+		bt_stream_class_common_borrow_event_header_field_type(
+			stream_class);
+	stream_event_ctx_type =
+		bt_stream_class_common_borrow_event_context_field_type(
+			stream_class);
+	event_context_type =
+		bt_event_class_common_borrow_context_field_type(event_class);
+	event_payload_type =
+		bt_event_class_common_borrow_payload_field_type(event_class);
 	ret = bt_validate_class_types(environment, packet_header_type,
 		packet_context_type, event_header_type, stream_event_ctx_type,
 		event_context_type, event_payload_type, trace_valid,
 		stream_class->valid, event_class->valid,
-		&validation_output, validation_flags);
-	BT_PUT(packet_header_type);
-	BT_PUT(packet_context_type);
-	BT_PUT(event_header_type);
-	BT_PUT(stream_event_ctx_type);
-	BT_PUT(event_context_type);
-	BT_PUT(event_payload_type);
+		validation_output, validation_flags, copy_field_type_func);
 	if (ret) {
 		/*
 		 * This means something went wrong during the validation
@@ -141,917 +115,743 @@ struct bt_event *bt_event_create(struct bt_event_class *event_class)
 		goto error;
 	}
 
-	if ((validation_output.valid_flags & validation_flags) !=
+	if ((validation_output->valid_flags & validation_flags) !=
 			validation_flags) {
 		/* Invalid trace/stream class/event class */
 		BT_LOGW("Invalid trace, stream class, or event class: "
-			"valid-flags=0x%x", validation_output.valid_flags);
+			"valid-flags=0x%x", validation_output->valid_flags);
 		goto error;
 	}
 
-	/*
-	 * At this point we know the trace (if associated to the stream
-	 * class), the stream class, and the event class, with their
-	 * current types, are valid. We may proceed with creating
-	 * the event.
-	 */
-	event = g_new0(struct bt_event, 1);
-	if (!event) {
-		BT_LOGE_STR("Failed to allocate one event.");
-		goto error;
-	}
+	goto end;
 
-	bt_object_init(event, bt_event_destroy);
+error:
+	bt_validation_output_put_types(validation_output);
+	ret = -1;
 
-	/*
-	 * event does not share a common ancestor with the event class; it has
-	 * to guarantee its existence by holding a reference. This reference
-	 * shall be released once the event is associated to a stream since,
-	 * from that point, the event and its class will share the same
-	 * lifetime.
-	 */
-	event->event_class = bt_get(event_class);
-	event->clock_values = g_hash_table_new_full(g_direct_hash,
-			g_direct_equal, bt_put, bt_put);
+end:
+	return ret;
+}
+
+static
+int bt_event_common_create_fields(
+		struct bt_stream_class_common *stream_class,
+		struct bt_validation_output *validation_output,
+		void *(*create_field_func)(void *),
+		void (*release_field_func)(void *),
+		void *(*create_header_field_func)(void *, void *),
+		void (*release_header_field_func)(void *),
+		struct bt_field_wrapper **header_field,
+		struct bt_field_common **stream_event_context_field,
+		struct bt_field_common **context_field,
+		struct bt_field_common **payload_field)
+{
+	int ret = 0;
 
-	if (validation_output.event_header_type) {
+	if (validation_output->event_header_type) {
 		BT_LOGD("Creating initial event header field: ft-addr=%p",
-			validation_output.event_header_type);
-		event_header =
-			bt_field_create(validation_output.event_header_type);
-		if (!event_header) {
+			validation_output->event_header_type);
+		*header_field =
+			create_header_field_func(stream_class,
+				validation_output->event_header_type);
+		if (!*header_field) {
 			BT_LOGE_STR("Cannot create initial event header field object.");
 			goto error;
 		}
 	}
 
-	if (validation_output.stream_event_ctx_type) {
+	if (validation_output->stream_event_ctx_type) {
 		BT_LOGD("Creating initial stream event context field: ft-addr=%p",
-			validation_output.stream_event_ctx_type);
-		stream_event_context = bt_field_create(
-			validation_output.stream_event_ctx_type);
-		if (!stream_event_context) {
+			validation_output->stream_event_ctx_type);
+		*stream_event_context_field = create_field_func(
+			validation_output->stream_event_ctx_type);
+		if (!*stream_event_context_field) {
 			BT_LOGE_STR("Cannot create initial stream event context field object.");
 			goto error;
 		}
 	}
 
-	if (validation_output.event_context_type) {
+	if (validation_output->event_context_type) {
 		BT_LOGD("Creating initial event context field: ft-addr=%p",
-			validation_output.event_context_type);
-		event_context = bt_field_create(
-			validation_output.event_context_type);
-		if (!event_context) {
+			validation_output->event_context_type);
+		*context_field = create_field_func(
+			validation_output->event_context_type);
+		if (!*context_field) {
 			BT_LOGE_STR("Cannot create initial event context field object.");
 			goto error;
 		}
 	}
 
-	if (validation_output.event_payload_type) {
+	if (validation_output->event_payload_type) {
 		BT_LOGD("Creating initial event payload field: ft-addr=%p",
-			validation_output.event_payload_type);
-		event_payload = bt_field_create(
-			validation_output.event_payload_type);
-		if (!event_payload) {
+			validation_output->event_payload_type);
+		*payload_field = create_field_func(
+			validation_output->event_payload_type);
+		if (!*payload_field) {
 			BT_LOGE_STR("Cannot create initial event payload field object.");
 			goto error;
 		}
 	}
 
-	/*
-	 * At this point all the fields are created, potentially from
-	 * validated copies of field types, so that the field types and
-	 * fields can be replaced in the trace, stream class,
-	 * event class, and created event.
-	 */
-	bt_validation_replace_types(trace, stream_class,
-		event_class, &validation_output, validation_flags);
-	BT_MOVE(event->event_header, event_header);
-	BT_MOVE(event->stream_event_context, stream_event_context);
-	BT_MOVE(event->context_payload, event_context);
-	BT_MOVE(event->fields_payload, event_payload);
-
-	/*
-	 * Put what was not moved in bt_validation_replace_types().
-	 */
-	bt_validation_output_put_types(&validation_output);
-
-	/*
-	 * Freeze the stream class since the event header must not be changed
-	 * anymore.
-	 */
-	bt_stream_class_freeze(stream_class);
-
-	/*
-	 * Mark stream class, and event class as valid since
-	 * they're all frozen now.
-	 */
-	stream_class->valid = 1;
-	event_class->valid = 1;
-
-	/* Put stuff we borrowed from the event class */
-	BT_PUT(stream_class);
-	BT_PUT(trace);
-	BT_LOGD("Created event object: addr=%p, event-class-name=\"%s\", "
-		"event-class-id=%" PRId64,
-		event, bt_event_class_get_name(event->event_class),
-		bt_event_class_get_id(event_class));
-	return event;
+	goto end;
 
 error:
-	bt_validation_output_put_types(&validation_output);
-	BT_PUT(event);
-	BT_PUT(stream_class);
-	BT_PUT(trace);
-	BT_PUT(event_header);
-	BT_PUT(stream_event_context);
-	BT_PUT(event_context);
-	BT_PUT(event_payload);
-	assert(!packet_header_type);
-	assert(!packet_context_type);
-	assert(!event_header_type);
-	assert(!stream_event_ctx_type);
-	assert(!event_context_type);
-	assert(!event_payload_type);
+	if (*header_field) {
+		release_header_field_func(*header_field);
+	}
 
-	return event;
-}
+	if (*stream_event_context_field) {
+		release_field_func(*stream_event_context_field);
+	}
 
-struct bt_event_class *bt_event_get_class(struct bt_event *event)
-{
-	struct bt_event_class *event_class = NULL;
+	if (*context_field) {
+		release_field_func(*context_field);
+	}
 
-	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		goto end;
+	if (*payload_field) {
+		release_field_func(*payload_field);
 	}
 
-	event_class = bt_get(bt_event_borrow_event_class(event));
+	ret = -1;
+
 end:
-	return event_class;
+	return ret;
 }
 
-struct bt_stream *bt_event_get_stream(struct bt_event *event)
+BT_HIDDEN
+int _bt_event_common_validate(struct bt_event_common *event)
 {
-	struct bt_stream *stream = NULL;
+	int ret = 0;
+	struct bt_stream_class_common *stream_class;
 
-	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		goto end;
+	BT_ASSERT(event);
+	if (event->header_field) {
+		ret = bt_field_common_validate_recursive(
+			event->header_field->field);
+		if (ret) {
+			BT_ASSERT_PRE_MSG("Invalid event's header field: "
+				"%![event-]+_e, %![field-]+_f",
+				event, event->header_field->field);
+			goto end;
+		}
 	}
 
+	stream_class = bt_event_class_common_borrow_stream_class(event->class);
+
 	/*
-	 * If the event has a parent, then this is its (writer) stream.
-	 * If the event has no parent, then if it has a packet, this
-	 * is its (non-writer) stream.
+	 * We should not have been able to create the event without associating
+	 * the event class to a stream class.
 	 */
-	if (event->base.parent) {
-		stream = (struct bt_stream *) bt_object_get_parent(event);
-	} else {
-		if (event->packet) {
-			stream = bt_get(event->packet->stream);
+	BT_ASSERT(stream_class);
+
+	if (stream_class->event_context_field_type) {
+		ret = bt_field_common_validate_recursive(
+			event->stream_event_context_field);
+		if (ret) {
+			BT_ASSERT_PRE_MSG("Invalid event's stream event context field: "
+				"%![event-]+_e, %![field-]+_f",
+				event, event->stream_event_context_field);
+			goto end;
 		}
 	}
 
+	if (event->class->context_field_type) {
+		ret = bt_field_common_validate_recursive(event->context_field);
+		if (ret) {
+			BT_ASSERT_PRE_MSG("Invalid event's payload field: "
+				"%![event-]+_e, %![field-]+_f",
+				event, event->context_field);
+			goto end;
+		}
+	}
+
+	ret = bt_field_common_validate_recursive(event->payload_field);
+	if (ret) {
+		BT_ASSERT_PRE_MSG("Invalid event's payload field: "
+			"%![event-]+_e, %![field-]+_f",
+			event, event->payload_field);
+		goto end;
+	}
+
 end:
-	return stream;
+	return ret;
 }
 
-int bt_event_set_payload(struct bt_event *event,
-		const char *name,
-		struct bt_field *payload)
+BT_HIDDEN
+void _bt_event_common_freeze(struct bt_event_common *event)
 {
-	int ret = 0;
+	BT_ASSERT(event);
 
-	if (!event || !payload) {
-		BT_LOGW("Invalid parameter: event or payload field is NULL: "
-			"event-addr=%p, payload-field-addr=%p",
-			event, payload);
-		ret = -1;
-		goto end;
+	if (event->frozen) {
+		return;
 	}
 
-	if (event->frozen) {
-		BT_LOGW("Invalid parameter: event is frozen: addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		ret = -1;
-		goto end;
+	BT_LOGD("Freezing event: addr=%p, "
+		"event-class-name=\"%s\", event-class-id=%" PRId64,
+		event, bt_event_class_common_get_name(event->class),
+		bt_event_class_common_get_id(event->class));
+
+	if (event->header_field) {
+		BT_LOGD_STR("Freezing event's header field.");
+		bt_field_common_set_is_frozen_recursive(
+			event->header_field->field, true);
 	}
 
-	if (name) {
-		ret = bt_field_structure_set_field_by_name(
-			event->fields_payload, name, payload);
-	} else {
-		struct bt_field_type *payload_type;
-
-		payload_type = bt_field_get_type(payload);
-
-		if (bt_field_type_compare(payload_type,
-				event->event_class->fields) == 0) {
-			bt_put(event->fields_payload);
-			bt_get(payload);
-			event->fields_payload = payload;
-		} else {
-			BT_LOGW("Invalid parameter: payload field type is different from the expected field type: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64,
-				event,
-				bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class));
-			ret = -1;
-		}
+	if (event->stream_event_context_field) {
+		BT_LOGD_STR("Freezing event's stream event context field.");
+		bt_field_common_set_is_frozen_recursive(
+			event->stream_event_context_field, true);
+	}
 
-		bt_put(payload_type);
+	if (event->context_field) {
+		BT_LOGD_STR("Freezing event's context field.");
+		bt_field_common_set_is_frozen_recursive(event->context_field, true);
 	}
 
-	if (ret) {
-		BT_LOGW("Failed to set event's payload field: event-addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64 ", "
-			"payload-field-name=\"%s\", payload-field-addr=%p",
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class),
-			name, payload);
-	} else {
-		BT_LOGV("Set event's payload field: event-addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64 ", "
-			"payload-field-name=\"%s\", payload-field-addr=%p",
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class),
-			name, payload);
+	if (event->payload_field) {
+		BT_LOGD_STR("Freezing event's payload field.");
+		bt_field_common_set_is_frozen_recursive(event->payload_field, true);
 	}
 
-end:
-	return ret;
+	event->frozen = 1;
 }
 
-struct bt_field *bt_event_get_event_payload(struct bt_event *event)
+BT_HIDDEN
+int bt_event_common_initialize(struct bt_event_common *event,
+		struct bt_event_class_common *event_class,
+		struct bt_clock_class *init_expected_clock_class,
+		bt_object_release_func release_func,
+		bt_validation_flag_copy_field_type_func field_type_copy_func,
+		bool must_be_in_trace,
+		int (*map_clock_classes_func)(struct bt_stream_class_common *stream_class,
+			struct bt_field_type_common *packet_context_field_type,
+			struct bt_field_type_common *event_header_field_type),
+		void *(*create_field_func)(void *),
+		void (*release_field_func)(void *),
+		void *(*create_header_field_func)(void *, void *),
+		void (*release_header_field_func)(void *))
 {
-	struct bt_field *payload = NULL;
+	int ret;
+	struct bt_trace_common *trace = NULL;
+	struct bt_stream_class_common *stream_class = NULL;
+	struct bt_field_wrapper *event_header = NULL;
+	struct bt_field_common *stream_event_context = NULL;
+	struct bt_field_common *event_context = NULL;
+	struct bt_field_common *event_payload = NULL;
+	struct bt_validation_output validation_output = { 0 };
+	struct bt_clock_class *expected_clock_class =
+		init_expected_clock_class ? bt_get(init_expected_clock_class) :
+		NULL;
 
-	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		goto end;
-	}
+	BT_ASSERT_PRE_NON_NULL(event_class, "Event class");
+	BT_LOGD("Initializing common event object: event-class-addr=%p, "
+		"event-class-name=\"%s\", event-class-id=%" PRId64,
+		event_class, bt_event_class_common_get_name(event_class),
+		bt_event_class_common_get_id(event_class));
 
-	if (!event->fields_payload) {
-		BT_LOGV("Event has no current payload field: addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		goto end;
-	}
+	stream_class = bt_event_class_common_borrow_stream_class(event_class);
+	BT_ASSERT_PRE(stream_class,
+		"Event class is not part of a stream class: %!+_E", event_class);
 
-	payload = event->fields_payload;
-	bt_get(payload);
-end:
-	return payload;
-}
+	/* The event class was frozen when added to its stream class */
+	BT_ASSERT(event_class->frozen);
+	trace = bt_stream_class_common_borrow_trace(stream_class);
 
-int bt_event_set_event_payload(struct bt_event *event,
-		struct bt_field *payload)
-{
-	return bt_event_set_payload(event, NULL, payload);
-}
+	if (must_be_in_trace) {
+		BT_ASSERT_PRE(trace,
+			"Event class's stream class is not part of a trace: "
+			"%![ec-]+_E, %![ec-]+_S", event_class, stream_class);
+	}
 
-struct bt_field *bt_event_get_payload(struct bt_event *event,
-		const char *name)
-{
-	struct bt_field *field = NULL;
+	/*
+	 * This must be called before anything that can fail because on
+	 * failure, the caller releases the reference to `event` to
+	 * destroy it.
+	 */
+	bt_object_init(event, release_func);
 
-	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		goto end;
+	if (!stream_class->frozen) {
+		/*
+		 * Because this function freezes the stream class,
+		 * validate that this stream class contains at most a
+		 * single clock class so that we set its expected clock
+		 * class for future checks.
+		 */
+		ret = bt_stream_class_common_validate_single_clock_class(
+			stream_class, &expected_clock_class);
+		if (ret) {
+			BT_LOGW("Event class's stream class or one of its event "
+				"classes contains a field type which is not "
+				"recursively mapped to the expected "
+				"clock class: "
+				"stream-class-addr=%p, "
+				"stream-class-id=%" PRId64 ", "
+				"stream-class-name=\"%s\", "
+				"expected-clock-class-addr=%p, "
+				"expected-clock-class-name=\"%s\"",
+				stream_class,
+				bt_stream_class_common_get_id(stream_class),
+				bt_stream_class_common_get_name(stream_class),
+				expected_clock_class,
+				expected_clock_class ?
+					bt_clock_class_get_name(expected_clock_class) :
+					NULL);
+			goto error;
+		}
 	}
 
-	if (name) {
-		field = bt_field_structure_get_field_by_name(
-			event->fields_payload, name);
-	} else {
-		field = event->fields_payload;
-		bt_get(field);
+	/* Validate the trace, the stream class, and the event class */
+	ret = bt_event_common_validate_types_for_create(
+		event_class, &validation_output, field_type_copy_func);
+	if (ret) {
+		/* bt_event_common_validate_types_for_create() logs errors */
+		goto error;
 	}
-end:
-	return field;
-}
 
-struct bt_field *bt_event_get_payload_by_index(
-		struct bt_event *event, uint64_t index)
-{
-	struct bt_field *field = NULL;
+	if (map_clock_classes_func) {
+		/*
+		 * Safe to automatically map selected fields to the
+		 * stream's clock's class here because the stream class
+		 * is about to be frozen.
+		 */
+		if (map_clock_classes_func(stream_class,
+				validation_output.packet_context_type,
+				validation_output.event_header_type)) {
+			BT_LOGW_STR("Cannot automatically map selected stream class's "
+				"field types to stream class's clock's class.");
+			goto error;
+		}
+	}
 
-	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		goto end;
+	/*
+	 * event does not share a common ancestor with the event class; it has
+	 * to guarantee its existence by holding a reference. This reference
+	 * shall be released once the event is associated to a stream since,
+	 * from that point, the event and its class will share the same
+	 * lifetime.
+	 */
+	event->class = bt_get(event_class);
+
+	ret = bt_event_common_create_fields(stream_class,
+		&validation_output,
+		create_field_func, release_field_func,
+		create_header_field_func, release_header_field_func,
+		&event_header, &stream_event_context, &event_context,
+		&event_payload);
+	if (ret) {
+		/* bt_event_common_create_fields() logs errors */
+		goto error;
 	}
 
-	field = bt_field_structure_get_field_by_index(event->fields_payload,
-		index);
-end:
-	return field;
-}
+	/*
+	 * At this point all the fields are created, potentially from
+	 * validated copies of field types, so that the field types and
+	 * fields can be replaced in the trace, stream class,
+	 * event class, and created event.
+	 */
+	bt_validation_replace_types(trace, stream_class, event_class,
+		&validation_output,
+		BT_VALIDATION_FLAG_STREAM | BT_VALIDATION_FLAG_EVENT);
+	event->header_field = event_header;
+	event_header = NULL;
+	event->stream_event_context_field = stream_event_context;
+	stream_event_context = NULL;
+	event->context_field = event_context;
+	event_context = NULL;
+	event->payload_field = event_payload;
+	event_payload = NULL;
 
-struct bt_field *bt_event_get_header(
-		struct bt_event *event)
-{
-	struct bt_field *header = NULL;
+	/*
+	 * Put what was not moved in bt_validation_replace_types().
+	 */
+	bt_validation_output_put_types(&validation_output);
 
-	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		goto end;
-	}
+	/*
+	 * Freeze the stream class since the event header must not be changed
+	 * anymore.
+	 */
+	bt_stream_class_common_freeze(stream_class);
 
-	if (!event->event_header) {
-		BT_LOGV("Event has no current header field: addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		goto end;
+	/*
+	 * It is safe to set the stream class's unique clock class
+	 * now because the stream class is frozen.
+	 */
+	if (expected_clock_class) {
+		BT_MOVE(stream_class->clock_class, expected_clock_class);
 	}
 
-	header = event->event_header;
-	bt_get(header);
-end:
-	return header;
-}
+	/*
+	 * Mark stream class, and event class as valid since
+	 * they're all frozen now.
+	 */
+	stream_class->valid = 1;
+	event_class->valid = 1;
 
-int bt_event_set_header(struct bt_event *event,
-		struct bt_field *header)
-{
-	int ret = 0;
-	struct bt_field_type *field_type = NULL;
-	struct bt_stream_class *stream_class = NULL;
+	/* Put stuff we borrowed from the event class */
+	BT_LOGD("Initialized event object: addr=%p, event-class-name=\"%s\", "
+		"event-class-id=%" PRId64,
+		event, bt_event_class_common_get_name(event->class),
+		bt_event_class_common_get_id(event->class));
+	goto end;
 
-	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		ret = -1;
-		goto end;
+error:
+	bt_validation_output_put_types(&validation_output);
+	bt_put(expected_clock_class);
+
+	if (event_header) {
+		release_header_field_func(event_header);
 	}
 
-	if (event->frozen) {
-		BT_LOGW("Invalid parameter: event is frozen: addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		ret = -1;
-		goto end;
+	if (stream_event_context) {
+		release_field_func(stream_event_context);
 	}
 
-	stream_class = (struct bt_stream_class *) bt_object_get_parent(
-			event->event_class);
-	/*
-	 * Ensure the provided header's type matches the one registered to the
-	 * stream class.
-	 */
-	if (header) {
-		field_type = bt_field_get_type(header);
-		if (bt_field_type_compare(field_type,
-				stream_class->event_header_type)) {
-			BT_LOGW("Invalid parameter: header field type is different from the expected field type: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64,
-				event,
-				bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class));
-			ret = -1;
-			goto end;
-		}
-	} else {
-		if (stream_class->event_header_type) {
-			BT_LOGW("Invalid parameter: setting no event header but event header field type is not NULL: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64 ", "
-				"event-header-ft-addr=%p",
-				event,
-				bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class),
-				stream_class->event_header_type);
-			ret = -1;
-			goto end;
-		}
+	if (event_context) {
+		release_field_func(event_context);
 	}
 
-	bt_put(event->event_header);
-	event->event_header = bt_get(header);
-	BT_LOGV("Set event's header field: event-addr=%p, "
-		"event-class-name=\"%s\", event-class-id=%" PRId64 ", "
-		"header-field-addr=%p",
-		event, bt_event_class_get_name(event->event_class),
-		bt_event_class_get_id(event->event_class), header);
+	if (event_payload) {
+		release_field_func(event_payload);
+	}
+
+	ret = -1;
+
 end:
-	bt_put(stream_class);
-	bt_put(field_type);
 	return ret;
 }
 
-struct bt_field *bt_event_get_event_context(
-		struct bt_event *event)
+static
+void bt_event_header_field_recycle(struct bt_field_wrapper *field_wrapper,
+		struct bt_stream_class *stream_class)
 {
-	struct bt_field *context = NULL;
+	BT_ASSERT(field_wrapper);
+	BT_LIB_LOGD("Recycling event header field: "
+		"addr=%p, %![sc-]+S, %![field-]+f", field_wrapper,
+		stream_class, field_wrapper->field);
+	bt_object_pool_recycle_object(
+		&stream_class->event_header_field_pool,
+		field_wrapper);
+}
 
-	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		goto end;
+static
+struct bt_field_wrapper *create_event_header_field(
+		struct bt_stream_class *stream_class,
+		struct bt_field_type_common *ft)
+{
+	struct bt_field_wrapper *field_wrapper = NULL;
+
+	field_wrapper = bt_field_wrapper_create(
+		&stream_class->event_header_field_pool, (void *) ft);
+	if (!field_wrapper) {
+		goto error;
 	}
 
-	if (!event->context_payload) {
-		BT_LOGV("Event has no current context field: addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		goto end;
+	goto end;
+
+error:
+	if (field_wrapper) {
+		bt_event_header_field_recycle(field_wrapper, stream_class);
+		field_wrapper = NULL;
 	}
 
-	context = event->context_payload;
-	bt_get(context);
 end:
-	return context;
+	return field_wrapper;
 }
 
-int bt_event_set_event_context(struct bt_event *event,
-		struct bt_field *context)
+BT_HIDDEN
+struct bt_event *bt_event_new(struct bt_event_class *event_class)
 {
-	int ret = 0;
-	struct bt_field_type *field_type = NULL;
+	int ret;
+	struct bt_event *event = NULL;
+	struct bt_stream_class *stream_class;
 
+	event = g_new0(struct bt_event, 1);
 	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		ret = -1;
-		goto end;
+		BT_LOGE_STR("Failed to allocate one event.");
+		goto error;
 	}
 
-	if (event->frozen) {
-		BT_LOGW("Invalid parameter: event is frozen: addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		ret = -1;
-		goto end;
+	ret = bt_event_common_initialize(BT_TO_COMMON(event),
+		BT_TO_COMMON(event_class), NULL, NULL,
+		(bt_validation_flag_copy_field_type_func) bt_field_type_copy,
+		true, NULL,
+		(void *) bt_field_create_recursive,
+		(void *) bt_field_destroy_recursive,
+		(void *) create_event_header_field,
+		(void *) bt_event_header_field_recycle);
+	if (ret) {
+		/* bt_event_common_initialize() logs errors */
+		goto error;
 	}
 
-	if (context) {
-		field_type = bt_field_get_type(context);
-
-		if (bt_field_type_compare(field_type,
-				event->event_class->context)) {
-			BT_LOGW("Invalid parameter: context field type is different from the expected field type: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64,
-				event,
-				bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class));
-			ret = -1;
-			goto end;
-		}
-	} else {
-		if (event->event_class->context) {
-			BT_LOGW("Invalid parameter: setting no event context but event context field type is not NULL: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64 ", "
-				"event-context-ft-addr=%p",
-				event,
-				bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class),
-				event->event_class->context);
-			ret = -1;
-			goto end;
+	bt_object_set_is_shared((void *) event, false);
+	event->clock_values = g_hash_table_new_full(g_direct_hash,
+			g_direct_equal, NULL,
+			(GDestroyNotify) bt_clock_value_recycle);
+	BT_ASSERT(event->clock_values);
+	stream_class = bt_event_class_borrow_stream_class(event_class);
+	BT_ASSERT(stream_class);
+
+	if (stream_class->common.clock_class) {
+		struct bt_clock_value *clock_value;
+
+		clock_value = bt_clock_value_create(
+			stream_class->common.clock_class);
+		if (!clock_value) {
+			BT_LIB_LOGE("Cannot create clock value from clock class: "
+				"%![cc-]+K", stream_class->common.clock_class);
+			goto error;
 		}
+
+		g_hash_table_insert(event->clock_values,
+			stream_class->common.clock_class, clock_value);
+	}
+
+	goto end;
+
+error:
+	if (event) {
+		bt_event_destroy(event);
+		event = NULL;
 	}
 
-	bt_put(event->context_payload);
-	event->context_payload = bt_get(context);
-	BT_LOGV("Set event's context field: event-addr=%p, "
-		"event-class-name=\"%s\", event-class-id=%" PRId64 ", "
-		"context-field-addr=%p",
-		event, bt_event_class_get_name(event->event_class),
-		bt_event_class_get_id(event->event_class), context);
 end:
-	bt_put(field_type);
-	return ret;
+	return event;
 }
 
-struct bt_field *bt_event_get_stream_event_context(
-		struct bt_event *event)
+BT_ASSERT_PRE_FUNC
+static inline
+void _bt_event_reset_dev_mode(struct bt_event *event)
 {
-	struct bt_field *stream_event_context = NULL;
+	GHashTableIter iter;
+	gpointer key, value;
 
-	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		goto end;
+	BT_ASSERT(event);
+
+	if (event->common.header_field) {
+		bt_field_common_set_is_frozen_recursive(
+			event->common.header_field->field, false);
+		bt_field_common_reset_recursive(
+			event->common.header_field->field);
 	}
 
-	if (!event->stream_event_context) {
-		BT_LOGV("Event has no current stream event context field: addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		goto end;
+	if (event->common.stream_event_context_field) {
+		bt_field_common_set_is_frozen_recursive(
+			event->common.stream_event_context_field, false);
+		bt_field_common_reset_recursive(
+			event->common.stream_event_context_field);
 	}
 
-	stream_event_context = event->stream_event_context;
-end:
-	return bt_get(stream_event_context);
+	if (event->common.context_field) {
+		bt_field_common_set_is_frozen_recursive(
+			event->common.context_field, false);
+		bt_field_common_reset_recursive(event->common.context_field);
+	}
+
+	if (event->common.payload_field) {
+		bt_field_common_set_is_frozen_recursive(
+			event->common.payload_field, false);
+		bt_field_common_reset_recursive(event->common.payload_field);
+	}
+
+	g_hash_table_iter_init(&iter, event->clock_values);
+	while (g_hash_table_iter_next(&iter, &key, &value)) {
+		struct bt_clock_value *clock_value = value;
+
+		BT_ASSERT(clock_value);
+		bt_clock_value_reset(clock_value);
+		bt_clock_value_set_is_frozen(clock_value, false);
+	}
 }
 
-int bt_event_set_stream_event_context(struct bt_event *event,
-		struct bt_field *stream_event_context)
+#ifdef BT_DEV_MODE
+# define bt_event_reset_dev_mode	_bt_event_reset_dev_mode
+#else
+# define bt_event_reset_dev_mode(_x)
+#endif
+
+static inline
+void bt_event_reset(struct bt_event *event)
 {
-	int ret = 0;
-	struct bt_field_type *field_type = NULL;
-	struct bt_stream_class *stream_class = NULL;
+	BT_ASSERT(event);
+	event->common.frozen = false;
+	bt_event_reset_dev_mode(event);
+	BT_PUT(event->packet);
+}
 
+BT_HIDDEN
+struct bt_event *bt_event_create(struct bt_event_class *event_class,
+		struct bt_packet *packet)
+{
+	int ret;
+	struct bt_event *event = NULL;
+
+	BT_ASSERT(event_class);
+	event = bt_object_pool_create_object(&event_class->event_pool);
 	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		ret = -1;
-		goto end;
+		BT_LIB_LOGE("Cannot allocate one event from event class's event pool: "
+			"%![event-class-]+E", event_class);
+		goto error;
 	}
 
-	if (event->frozen) {
-		BT_LOGW("Invalid parameter: event is frozen: addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		ret = -1;
-		goto end;
+	if (!event->common.class) {
+		event->common.class = bt_get(event_class);
 	}
 
-	stream_class = bt_event_class_get_stream_class(event->event_class);
-	/*
-	 * We should not have been able to create the event without associating
-	 * the event class to a stream class.
-	 */
-	assert(stream_class);
+	BT_ASSERT(packet);
+	ret = bt_event_set_packet(event, packet);
+	if (ret) {
+		BT_LIB_LOGE("Cannot set event's packet: "
+			"%![event-]+e, %![packet-]+a", event, packet);
+		goto error;
+	}
 
-	if (stream_event_context) {
-		field_type = bt_field_get_type(stream_event_context);
-		if (bt_field_type_compare(field_type,
-				stream_class->event_context_type)) {
-			BT_LOGW("Invalid parameter: stream event context field type is different from the expected field type: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64,
-				event,
-				bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class));
-			ret = -1;
-			goto end;
-		}
-	} else {
-		if (stream_class->event_context_type) {
-			BT_LOGW("Invalid parameter: setting no stream event context but stream event context field type is not NULL: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64 ", "
-				"stream-event-context-ft-addr=%p",
-				event,
-				bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class),
-				stream_class->event_context_type);
-			ret = -1;
-			goto end;
-		}
+	goto end;
+
+error:
+	if (event) {
+		bt_event_recycle(event);
+		event = NULL;
 	}
 
-	bt_get(stream_event_context);
-	BT_MOVE(event->stream_event_context, stream_event_context);
-	BT_LOGV("Set event's stream event context field: event-addr=%p, "
-		"event-class-name=\"%s\", event-class-id=%" PRId64 ", "
-		"stream-event-context-field-addr=%p",
-		event, bt_event_class_get_name(event->event_class),
-		bt_event_class_get_id(event->event_class),
-		stream_event_context);
 end:
-	BT_PUT(stream_class);
-	bt_put(field_type);
-	return ret;
+	return event;
 }
 
-/* Pre-2.0 CTF writer backward compatibility */
-void bt_ctf_event_get(struct bt_event *event)
+struct bt_event_class *bt_event_borrow_class(struct bt_event *event)
 {
-	bt_get(event);
+	BT_ASSERT_PRE_NON_NULL(event, "Event");
+	return BT_FROM_COMMON(
+		bt_event_common_borrow_class(BT_TO_COMMON(event)));
 }
 
-/* Pre-2.0 CTF writer backward compatibility */
-void bt_ctf_event_put(struct bt_event *event)
+struct bt_stream *bt_event_borrow_stream(struct bt_event *event)
 {
-	bt_put(event);
+	BT_ASSERT_PRE_NON_NULL(event, "Event");
+	return event->packet ? event->packet->stream : NULL;
 }
 
-void bt_event_destroy(struct bt_object *obj)
+struct bt_field *bt_event_borrow_payload(struct bt_event *event)
 {
-	struct bt_event *event;
+	return BT_FROM_COMMON(
+		bt_event_common_borrow_payload(BT_TO_COMMON(event)));
+}
 
-	event = container_of(obj, struct bt_event, base);
-	BT_LOGD("Destroying event: addr=%p, "
-		"event-class-name=\"%s\", event-class-id=%" PRId64,
-		event, bt_event_class_get_name(event->event_class),
-		bt_event_class_get_id(event->event_class));
+struct bt_field *bt_event_borrow_header(struct bt_event *event)
+{
+	return BT_FROM_COMMON(
+		bt_event_common_borrow_header(BT_TO_COMMON(event)));
+}
 
-	if (!event->base.parent) {
-		/*
-		 * Event was keeping a reference to its class since it shared no
-		 * common ancestor with it to guarantee they would both have the
-		 * same lifetime.
-		 */
-		bt_put(event->event_class);
+struct bt_field *bt_event_borrow_context(struct bt_event *event)
+{
+	return BT_FROM_COMMON(
+		bt_event_common_borrow_context(BT_TO_COMMON(event)));
+}
+
+struct bt_field *bt_event_borrow_stream_event_context(
+		struct bt_event *event)
+{
+	return BT_FROM_COMMON(bt_event_common_borrow_stream_event_context(
+		BT_TO_COMMON(event)));
+}
+
+static
+void release_event_header_field(struct bt_field_wrapper *field_wrapper,
+		struct bt_event_common *event_common)
+{
+	struct bt_event *event = BT_FROM_COMMON(event_common);
+	struct bt_event_class *event_class = bt_event_borrow_class(event);
+
+	if (!event_class) {
+		bt_field_wrapper_destroy(field_wrapper);
+	} else {
+		struct bt_stream_class *stream_class =
+			bt_event_class_borrow_stream_class(event_class);
+
+		BT_ASSERT(stream_class);
+		bt_event_header_field_recycle(field_wrapper, stream_class);
 	}
+}
+
+BT_HIDDEN
+void bt_event_destroy(struct bt_event *event)
+{
+	BT_ASSERT(event);
+	bt_event_common_finalize((void *) event,
+		(void *) bt_field_destroy_recursive,
+		(void *) release_event_header_field);
 	g_hash_table_destroy(event->clock_values);
-	BT_LOGD_STR("Putting event's header field.");
-	bt_put(event->event_header);
-	BT_LOGD_STR("Putting event's stream event context field.");
-	bt_put(event->stream_event_context);
-	BT_LOGD_STR("Putting event's context field.");
-	bt_put(event->context_payload);
-	BT_LOGD_STR("Putting event's payload field.");
-	bt_put(event->fields_payload);
 	BT_LOGD_STR("Putting event's packet.");
 	bt_put(event->packet);
 	g_free(event);
 }
 
-struct bt_clock_value *bt_event_get_clock_value(
+struct bt_clock_value *bt_event_borrow_clock_value(
 		struct bt_event *event, struct bt_clock_class *clock_class)
 {
 	struct bt_clock_value *clock_value = NULL;
 
-	if (!event || !clock_class) {
-		BT_LOGW("Invalid parameter: event or clock class is NULL: "
-			"event-addr=%p, clock-class-addr=%p",
-			event, clock_class);
-		goto end;
-	}
-
+	BT_ASSERT_PRE_NON_NULL(event, "Event");
+	BT_ASSERT_PRE_NON_NULL(clock_class, "Clock class");
 	clock_value = g_hash_table_lookup(event->clock_values, clock_class);
 	if (!clock_value) {
 		BT_LOGV("No clock value associated to the given clock class: "
 			"event-addr=%p, event-class-name=\"%s\", "
 			"event-class-id=%" PRId64 ", clock-class-addr=%p, "
 			"clock-class-name=\"%s\"", event,
-			bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class),
+			bt_event_class_common_get_name(event->common.class),
+			bt_event_class_common_get_id(event->common.class),
 			clock_class, bt_clock_class_get_name(clock_class));
 		goto end;
 	}
 
-	bt_get(clock_value);
 end:
 	return clock_value;
 }
 
-int bt_event_set_clock_value(struct bt_event *event,
-		struct bt_clock_value *value)
-{
-	int ret = 0;
-	struct bt_trace *trace;
-	struct bt_stream_class *stream_class;
-	struct bt_event_class *event_class;
-	struct bt_clock_class *clock_class = NULL;
-
-	if (!event || !value) {
-		BT_LOGW("Invalid parameter: event or clock value is NULL: "
-			"event-addr=%p, clock-value-addr=%p",
-			event, value);
-		ret = -1;
-		goto end;
-	}
-
-	if (event->frozen) {
-		BT_LOGW("Invalid parameter: event is frozen: addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		ret = -1;
-		goto end;
-	}
-
-	clock_class = bt_clock_value_get_class(value);
-	event_class = bt_event_borrow_event_class(event);
-	assert(event_class);
-	stream_class = bt_event_class_borrow_stream_class(event_class);
-	assert(stream_class);
-	trace = bt_stream_class_borrow_trace(stream_class);
-	assert(trace);
-
-	if (!bt_trace_has_clock_class(trace, clock_class)) {
-		BT_LOGW("Invalid parameter: clock class is not part of event's trace: "
-			"event-addr=%p, event-class-name=\"%s\", "
-			"event-class-id=%" PRId64 ", clock-class-addr=%p, "
-			"clock-class-name=\"%s\"",
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class),
-			clock_class, bt_clock_class_get_name(clock_class));
-		ret = -1;
-		goto end;
-	}
-
-	g_hash_table_insert(event->clock_values, clock_class, bt_get(value));
-	BT_LOGV("Set event's clock value: "
-		"event-addr=%p, event-class-name=\"%s\", "
-		"event-class-id=%" PRId64 ", clock-class-addr=%p, "
-		"clock-class-name=\"%s\", clock-value-addr=%p, "
-		"clock-value-cycles=%" PRIu64,
-		event, bt_event_class_get_name(event->event_class),
-		bt_event_class_get_id(event->event_class),
-		clock_class, bt_clock_class_get_name(clock_class),
-		value, value->value);
-	clock_class = NULL;
-
-end:
-	bt_put(clock_class);
-	return ret;
-}
-
-BT_HIDDEN
-int bt_event_validate(struct bt_event *event)
-{
-	/* Make sure each field's payload has been set */
-	int ret;
-	struct bt_stream_class *stream_class = NULL;
-
-	assert(event);
-	if (event->event_header) {
-		ret = bt_field_validate(event->event_header);
-		if (ret) {
-			BT_LOGD("Invalid event's header field: "
-					"event-addr=%p, event-class-name=\"%s\", "
-					"event-class-id=%" PRId64,
-					event, bt_event_class_get_name(event->event_class),
-					bt_event_class_get_id(event->event_class));
-			goto end;
-		}
-	}
-
-	stream_class = bt_event_class_get_stream_class(event->event_class);
-	/*
-	 * We should not have been able to create the event without associating
-	 * the event class to a stream class.
-	 */
-	assert(stream_class);
-	if (stream_class->event_context_type) {
-		ret = bt_field_validate(event->stream_event_context);
-		if (ret) {
-			BT_LOGD("Invalid event's stream event context field: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64,
-				event,
-				bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class));
-			goto end;
-		}
-	}
-
-	ret = bt_field_validate(event->fields_payload);
-	if (ret) {
-		BT_LOGD("Invalid event's payload field: "
-			"event-addr=%p, event-class-name=\"%s\", "
-			"event-class-id=%" PRId64,
-			event,
-			bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		goto end;
-	}
-
-	if (event->event_class->context) {
-		BT_LOGD("Invalid event's context field: "
-			"event-addr=%p, event-class-name=\"%s\", "
-			"event-class-id=%" PRId64,
-			event,
-			bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		ret = bt_field_validate(event->context_payload);
-	}
-end:
-	bt_put(stream_class);
-	return ret;
-}
-
-BT_HIDDEN
-int bt_event_serialize(struct bt_event *event,
-		struct bt_stream_pos *pos,
-		enum bt_byte_order native_byte_order)
-{
-	int ret = 0;
-
-	assert(event);
-	assert(pos);
-
-	BT_LOGV_STR("Serializing event's context field.");
-	if (event->context_payload) {
-		ret = bt_field_serialize(event->context_payload, pos,
-			native_byte_order);
-		if (ret) {
-			BT_LOGW("Cannot serialize event's context field: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64,
-				event,
-				bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class));
-			goto end;
-		}
-	}
-
-	BT_LOGV_STR("Serializing event's payload field.");
-	if (event->fields_payload) {
-		ret = bt_field_serialize(event->fields_payload, pos,
-			native_byte_order);
-		if (ret) {
-			BT_LOGW("Cannot serialize event's payload field: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64,
-				event,
-				bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class));
-			goto end;
-		}
-	}
-end:
-	return ret;
-}
-
-struct bt_packet *bt_event_get_packet(struct bt_event *event)
+struct bt_packet *bt_event_borrow_packet(struct bt_event *event)
 {
 	struct bt_packet *packet = NULL;
 
-	if (!event) {
-		BT_LOGW_STR("Invalid parameter: event is NULL.");
-		goto end;
-	}
-
+	BT_ASSERT_PRE_NON_NULL(event, "Event");
 	if (!event->packet) {
 		BT_LOGV("Event has no current packet: addr=%p, "
 			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
+			event, bt_event_class_common_get_name(event->common.class),
+			bt_event_class_common_get_id(event->common.class));
 		goto end;
 	}
 
-	packet = bt_get(event->packet);
+	packet = event->packet;
+
 end:
 	return packet;
 }
 
-int bt_event_set_packet(struct bt_event *event,
-		struct bt_packet *packet)
+BT_HIDDEN
+int bt_event_set_packet(struct bt_event *event, struct bt_packet *packet)
 {
-	struct bt_stream_class *event_stream_class = NULL;
-	struct bt_stream_class *packet_stream_class = NULL;
-	struct bt_stream *stream = NULL;
-	int ret = 0;
-
-	if (!event || !packet) {
-		BT_LOGW("Invalid parameter: event or packet is NULL: "
-			"event-addr=%p, packet-addr=%p",
-			event, packet);
-		ret = -1;
-		goto end;
-	}
-
-	if (event->frozen) {
-		BT_LOGW("Invalid parameter: event is frozen: addr=%p, "
-			"event-class-name=\"%s\", event-class-id=%" PRId64,
-			event, bt_event_class_get_name(event->event_class),
-			bt_event_class_get_id(event->event_class));
-		ret = -1;
-		goto end;
-	}
+	BT_ASSERT_PRE_NON_NULL(event, "Event");
+	BT_ASSERT_PRE_NON_NULL(packet, "Packet");
+	BT_ASSERT_PRE_EVENT_COMMON_HOT(BT_TO_COMMON(event), "Event");
 
 	/*
 	 * Make sure the new packet was created by this event's
 	 * stream, if it is set.
 	 */
-	stream = bt_event_get_stream(event);
-	if (stream) {
-		if (packet->stream != stream) {
-			BT_LOGW("Invalid parameter: packet's stream and event's stream differ: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64 ", packet-stream-addr=%p, "
-				"event-stream-addr=%p",
-				event, bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class),
-				packet->stream, stream);
-			ret = -1;
-			goto end;
-		}
+	if (bt_event_borrow_stream(event)) {
+		BT_ASSERT_PRE(packet->stream == bt_event_borrow_stream(event),
+			"Packet's stream and event's stream differ: "
+			"%![event-]+e, %![packet-]+a",
+			event, packet);
 	} else {
-		event_stream_class =
-			bt_event_class_get_stream_class(event->event_class);
-		packet_stream_class =
-			bt_stream_get_class(packet->stream);
-
-		assert(event_stream_class);
-		assert(packet_stream_class);
-
-		if (event_stream_class != packet_stream_class) {
-			BT_LOGW("Invalid parameter: packet's stream class and event's stream class differ: "
-				"event-addr=%p, event-class-name=\"%s\", "
-				"event-class-id=%" PRId64 ", packet-stream-class-addr=%p, "
-				"event-stream-class-addr=%p",
-				event, bt_event_class_get_name(event->event_class),
-				bt_event_class_get_id(event->event_class),
-				packet_stream_class, event_stream_class);
-			ret = -1;
-			goto end;
-		}
+		BT_ASSERT_PRE(bt_event_class_borrow_stream_class(
+			BT_FROM_COMMON(event->common.class)) ==
+			BT_FROM_COMMON(packet->stream->common.stream_class),
+			"Packet's stream class and event's stream class differ: "
+			"%![event-]+e, %![packet-]+a",
+			event, packet);
 	}
 
 	bt_get(packet);
@@ -1059,38 +859,78 @@ int bt_event_set_packet(struct bt_event *event,
 	BT_LOGV("Set event's packet: event-addr=%p, "
 		"event-class-name=\"%s\", event-class-id=%" PRId64 ", "
 		"packet-addr=%p",
-		event, bt_event_class_get_name(event->event_class),
-		bt_event_class_get_id(event->event_class), packet);
-
-end:
-	BT_PUT(stream);
-	BT_PUT(event_stream_class);
-	BT_PUT(packet_stream_class);
+		event, bt_event_class_common_get_name(event->common.class),
+		bt_event_class_common_get_id(event->common.class), packet);
+	return 0;
+}
 
-	return ret;
+BT_HIDDEN
+void _bt_event_freeze(struct bt_event *event)
+{
+	_bt_event_common_freeze(BT_TO_COMMON(event));
+	BT_LOGD_STR("Freezing event's packet.");
+	bt_packet_freeze(event->packet);
 }
 
 BT_HIDDEN
-void bt_event_freeze(struct bt_event *event)
+void bt_event_recycle(struct bt_event *event)
 {
-	assert(event);
+	struct bt_event_class *event_class;
 
-	if (event->frozen) {
-		return;
-	}
+	BT_ASSERT(event);
+	BT_LIB_LOGD("Recycling event: %!+e", event);
 
-	BT_LOGD("Freezing event: addr=%p, "
-		"event-class-name=\"%s\", event-class-id=%" PRId64,
-		event, bt_event_class_get_name(event->event_class),
-		bt_event_class_get_id(event->event_class));
-	bt_packet_freeze(event->packet);
-	BT_LOGD_STR("Freezing event's header field.");
-	bt_field_freeze(event->event_header);
-	BT_LOGD_STR("Freezing event's stream event context field.");
-	bt_field_freeze(event->stream_event_context);
-	BT_LOGD_STR("Freezing event's context field.");
-	bt_field_freeze(event->context_payload);
-	BT_LOGD_STR("Freezing event's payload field.");
-	bt_field_freeze(event->fields_payload);
-	event->frozen = 1;
+	/*
+	 * Those are the important ordered steps:
+	 *
+	 * 1. Reset the event object (put any permanent reference it
+	 *    has, unfreeze it and its fields in developer mode, etc.),
+	 *    but do NOT put its class's reference. This event class
+	 *    contains the pool to which we're about to recycle this
+	 *    event object, so we must guarantee its existence thanks
+	 *    to this existing reference.
+	 *
+	 * 2. Move the event class reference to our `event_class`
+	 *    variable so that we can set the event's class member
+	 *    to NULL before recycling it. We CANNOT do this after
+	 *    we put the event class reference because this bt_put()
+	 *    could destroy the event class, also destroying its
+	 *    event pool, thus also destroying our event object (this
+	 *    would result in an invalid write access).
+	 *
+	 * 3. Recycle the event object.
+	 *
+	 * 4. Put our event class reference.
+	 */
+	bt_event_reset(event);
+	event_class = BT_FROM_COMMON(event->common.class);
+	BT_ASSERT(event_class);
+	event->common.class = NULL;
+	bt_object_pool_recycle_object(&event_class->event_pool, event);
+	bt_put(event_class);
+}
+
+int bt_event_move_header(struct bt_event *event,
+		struct bt_event_header_field *header_field)
+{
+	struct bt_stream_class *stream_class;
+	struct bt_field_wrapper *field_wrapper = (void *) header_field;
+
+	BT_ASSERT_PRE_NON_NULL(event, "Event");
+	BT_ASSERT_PRE_NON_NULL(field_wrapper, "Header field");
+	BT_ASSERT_PRE_HOT(BT_TO_COMMON(event), "Event", ": +%!+e", event);
+	stream_class = bt_event_class_borrow_stream_class(
+		bt_event_borrow_class(event));
+	BT_ASSERT_PRE(stream_class->common.event_header_field_type,
+		"Stream class has no event header field type: %!+S",
+		stream_class);
+
+	/* Recycle current header field: always exists */
+	BT_ASSERT(event->common.header_field);
+	bt_event_header_field_recycle(event->common.header_field,
+		stream_class);
+
+	/* Move new field */
+	event->common.header_field = (void *) field_wrapper;
+	return 0;
 }