[PATCH V11 13/15] monitor/hmp: display IOThread holders

[Zhang Chen <zhangckid@gmail.com>]

Display holder information in info iothreads to aid manual debugging.
Omit the holders line when an IOThread has no holders.

Signed-off-by: Zhang Chen <zhangckid@gmail.com>
---
 monitor/hmp-cmds.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index e9fb8d827a..de37f83a72 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -240,11 +240,33 @@ void hmp_info_iothreads(Monitor *mon, const QDict *qdict)
     IOThreadInfoList *info_list = qmp_query_iothreads(NULL);
     IOThreadInfoList *info;
     IOThreadInfo *value;
+    IOThreadHolderList *h;
 
     for (info = info_list; info; info = info->next) {
         value = info->value;
         monitor_printf(mon, "%s:\n", value->id);
         monitor_printf(mon, "  thread_id=%" PRId64 "\n", value->thread_id);
+        if (value->holders) {
+            monitor_printf(mon, "  holders=");
+            for (h = value->holders; h; h = h->next) {
+                IOThreadHolder *holder = h->value;
+
+                switch (holder->type) {
+                case IO_THREAD_HOLDER_KIND_BLOCK_EXPORT:
+                    monitor_printf(mon, "[block-export: %s]",
+                                   holder->u.block_export.export_id);
+                    break;
+                case IO_THREAD_HOLDER_KIND_QOM_OBJECT:
+                    monitor_printf(mon, "[qom-path: %s]",
+                                   holder->u.qom_object.qom_path);
+                    break;
+                default:
+                    monitor_printf(mon, "[unknown]");
+                    break;
+                }
+            }
+            monitor_printf(mon, "\n");
+        }
         monitor_printf(mon, "  poll-max-ns=%" PRId64 "\n", value->poll_max_ns);
         monitor_printf(mon, "  poll-grow=%" PRId64 "\n", value->poll_grow);
         monitor_printf(mon, "  poll-shrink=%" PRId64 "\n", value->poll_shrink);
-- 
2.53.0