muxer: append causes on some _next iterator method code paths

The goal of this patch (on top of the fact that having more error causes
is nice) is to ensure that if an error status is returned to
muxer_msg_iter_do_next, an error is set on the current thread.  This
will help for the next patch, which will save and restore the error in
this function.

Change-Id: I7221af107f330ab5ded10b69f24121be6ad1678c
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/2382
Reviewed-by: Francis Deslauriers <francis.deslauriers@efficios.com>

diff --git a/src/plugins/utils/muxer/muxer.c b/src/plugins/utils/muxer/muxer.c
index a2db3cb9ee398dd3e523a9d4d6dbc91cd042e5ab..1571167cbea31e485a1a13ef8abd13a56815714f 100644 (file)
--- a/src/plugins/utils/muxer/muxer.c
+++ b/src/plugins/utils/muxer/muxer.c
@@ -382,8 +382,7 @@ bt_component_class_message_iterator_next_method_status muxer_upstream_msg_iter_n
                struct muxer_upstream_msg_iter *muxer_upstream_msg_iter,
                bool *is_ended)
 {
-       struct muxer_comp *muxer_comp =
-               muxer_upstream_msg_iter->muxer_comp;
+       struct muxer_comp *muxer_comp = muxer_upstream_msg_iter->muxer_comp;
        bt_component_class_message_iterator_next_method_status status;
        bt_message_iterator_next_status input_port_iter_status;
        bt_message_array_const msgs;
@@ -438,10 +437,19 @@ bt_component_class_message_iterator_next_method_status muxer_upstream_msg_iter_n
                *is_ended = true;
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
                break;
+       case BT_MESSAGE_ITERATOR_NEXT_STATUS_ERROR:
+       case BT_MESSAGE_ITERATOR_NEXT_STATUS_MEMORY_ERROR:
+               /* Error status code */
+               BT_COMP_LOGE_APPEND_CAUSE(muxer_comp->self_comp,
+                       "Upstream iterator's next method returned an error: status=%s",
+                       bt_common_func_status_string(input_port_iter_status));
+               status = (int) input_port_iter_status;
+               break;
        default:
-               /* Error or unsupported status code */
-               BT_COMP_LOGE("Error or unsupported status code: "
-                       "status-code=%d", input_port_iter_status);
+               /* Unsupported status code */
+               BT_COMP_LOGE_APPEND_CAUSE(muxer_comp->self_comp,
+                       "Unsupported status code: status=%s",
+                       bt_common_func_status_string(input_port_iter_status));
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                break;
        }
@@ -917,10 +925,8 @@ validate_muxer_upstream_msg_iter(
        struct muxer_upstream_msg_iter *muxer_upstream_msg_iter,
        bool *is_ended)
 {
-       struct muxer_comp *muxer_comp =
-               muxer_upstream_msg_iter->muxer_comp;
-       bt_component_class_message_iterator_next_method_status status =
-               BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
+       struct muxer_comp *muxer_comp = muxer_upstream_msg_iter->muxer_comp;
+       bt_component_class_message_iterator_next_method_status status;
 
        BT_COMP_LOGD("Validating muxer's upstream message iterator wrapper: "
                "muxer-upstream-msg-iter-wrap-addr=%p",
@@ -932,6 +938,7 @@ validate_muxer_upstream_msg_iter(
                        "queue-len=%u, upstream-msg-iter-addr=%p",
                        muxer_upstream_msg_iter->msgs->length,
                        muxer_upstream_msg_iter->msg_iter);
+               status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
                goto end;
        }
 
@@ -949,8 +956,7 @@ validate_muxer_upstream_msg_iters(
                struct muxer_msg_iter *muxer_msg_iter)
 {
        struct muxer_comp *muxer_comp = muxer_msg_iter->muxer_comp;
-       bt_component_class_message_iterator_next_method_status status =
-               BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
+       bt_component_class_message_iterator_next_method_status status;
        size_t i;
 
        BT_COMP_LOGD("Validating muxer's upstream message iterator wrappers: "
@@ -968,7 +974,8 @@ validate_muxer_upstream_msg_iters(
                        muxer_upstream_msg_iter, &is_ended);
                if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                        if (status < 0) {
-                               BT_COMP_LOGE("Cannot validate muxer's upstream message iterator wrapper: "
+                               BT_COMP_LOGE_APPEND_CAUSE(muxer_comp->self_comp,
+                                       "Cannot validate muxer's upstream message iterator wrapper: "
                                        "muxer-msg-iter-addr=%p, "
                                        "muxer-upstream-msg-iter-wrap-addr=%p",
                                        muxer_msg_iter,
@@ -1009,6 +1016,8 @@ validate_muxer_upstream_msg_iters(
                }
        }
 
+       status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
+
 end:
        return status;
 }
@@ -1040,7 +1049,8 @@ bt_component_class_message_iterator_next_method_status muxer_msg_iter_do_next_on
                        &next_return_ts);
        if (status < 0 || status == BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_END) {
                if (status < 0) {
-                       BT_COMP_LOGE("Cannot find the youngest upstream message iterator wrapper: "
+                       BT_COMP_LOGE_APPEND_CAUSE(muxer_comp->self_comp,
+                               "Cannot find the youngest upstream message iterator wrapper: "
                                "status=%s",
                                bt_common_func_status_string(status));
                } else {
@@ -1053,7 +1063,8 @@ bt_component_class_message_iterator_next_method_status muxer_msg_iter_do_next_on
        }
 
        if (next_return_ts < muxer_msg_iter->last_returned_ts_ns) {
-               BT_COMP_LOGE("Youngest upstream message iterator wrapper's timestamp is less than muxer's message iterator's last returned timestamp: "
+               BT_COMP_LOGE_APPEND_CAUSE(muxer_comp->self_comp,
+                       "Youngest upstream message iterator wrapper's timestamp is less than muxer's message iterator's last returned timestamp: "
                        "muxer-msg-iter-addr=%p, ts=%" PRId64 ", "
                        "last-returned-ts=%" PRId64,
                        muxer_msg_iter, next_return_ts,