[PULL 02/15] qio: Add trace points to net_listener

[Eric Blake <eblake@redhat.com>]

Upcoming patches will adjust how net_listener watches for new client
connections; adding trace points now makes it easier to debug that the
changes work as intended.  For example, adding
--trace='qio_net_listener*' to the qemu-storage-daemon command line
before --nbd-server will track when the server first starts listening
for clients.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-ID: <20251113011625.878876-17-eblake@redhat.com>
---
 io/net-listener.c | 10 ++++++++++
 io/trace-events   |  5 +++++
 2 files changed, 15 insertions(+)

diff --git a/io/net-listener.c b/io/net-listener.c
index 47405965a66..007acbd5b18 100644
--- a/io/net-listener.c
+++ b/io/net-listener.c
@@ -23,6 +23,7 @@
 #include "io/dns-resolver.h"
 #include "qapi/error.h"
 #include "qemu/module.h"
+#include "trace.h"

 QIONetListener *qio_net_listener_new(void)
 {
@@ -50,6 +51,7 @@ static gboolean qio_net_listener_channel_func(QIOChannel *ioc,
         return TRUE;
     }

+    trace_qio_net_listener_callback(listener, listener->io_func);
     if (listener->io_func) {
         listener->io_func(listener, sioc, listener->io_data);
     }
@@ -123,6 +125,7 @@ void qio_net_listener_add(QIONetListener *listener,
     object_ref(OBJECT(sioc));
     listener->connected = true;

+    trace_qio_net_listener_watch(listener, listener->io_func, "add");
     if (listener->io_func != NULL) {
         object_ref(OBJECT(listener));
         listener->io_source[listener->nsioc] = qio_channel_add_watch_source(
@@ -143,6 +146,8 @@ void qio_net_listener_set_client_func_full(QIONetListener *listener,
 {
     size_t i;

+    trace_qio_net_listener_unwatch(listener, listener->io_func,
+                                   "set_client_func");
     if (listener->io_notify) {
         listener->io_notify(listener->io_data);
     }
@@ -158,6 +163,8 @@ void qio_net_listener_set_client_func_full(QIONetListener *listener,
         }
     }

+    trace_qio_net_listener_watch(listener, listener->io_func,
+                                 "set_client_func");
     if (listener->io_func != NULL) {
         for (i = 0; i < listener->nsioc; i++) {
             object_ref(OBJECT(listener));
@@ -218,6 +225,7 @@ QIOChannelSocket *qio_net_listener_wait_client(QIONetListener *listener)
     };
     size_t i;

+    trace_qio_net_listener_unwatch(listener, listener->io_func, "wait_client");
     for (i = 0; i < listener->nsioc; i++) {
         if (listener->io_source[i]) {
             g_source_destroy(listener->io_source[i]);
@@ -247,6 +255,7 @@ QIOChannelSocket *qio_net_listener_wait_client(QIONetListener *listener)
     g_main_loop_unref(loop);
     g_main_context_unref(ctxt);

+    trace_qio_net_listener_watch(listener, listener->io_func, "wait_client");
     if (listener->io_func != NULL) {
         for (i = 0; i < listener->nsioc; i++) {
             object_ref(OBJECT(listener));
@@ -268,6 +277,7 @@ void qio_net_listener_disconnect(QIONetListener *listener)
         return;
     }

+    trace_qio_net_listener_unwatch(listener, listener->io_func, "disconnect");
     for (i = 0; i < listener->nsioc; i++) {
         if (listener->io_source[i]) {
             g_source_destroy(listener->io_source[i]);
diff --git a/io/trace-events b/io/trace-events
index dc3a63ba1fb..10976eca5fe 100644
--- a/io/trace-events
+++ b/io/trace-events
@@ -72,3 +72,8 @@ qio_channel_command_new_pid(void *ioc, int writefd, int readfd, int pid) "Comman
 qio_channel_command_new_spawn(void *ioc, const char *binary, int flags) "Command new spawn ioc=%p binary=%s flags=%d"
 qio_channel_command_abort(void *ioc, int pid) "Command abort ioc=%p pid=%d"
 qio_channel_command_wait(void *ioc, int pid, int ret, int status) "Command abort ioc=%p pid=%d ret=%d status=%d"
+
+# net-listener.c
+qio_net_listener_watch(void *listener, void *func, const char *extra) "Net listener=%p watch enabled func=%p by %s"
+qio_net_listener_unwatch(void *listener, void *func, const char *extra) "Net listener=%p watch disabled func=%p by %s"
+qio_net_listener_callback(void *listener, void *func) "Net listener=%p callback forwarding to func=%p"
-- 
2.51.1