leakstracer: Add API for tracking and checkpointing objects

This feature was previously available only through the SIGUSR2 signal,
which meant it wasn't available on platforms that don't have UNIX
signals, such as Windows and with applications that already use
SIGUSR1 for something else.

Now we have action-signals for doing the same. These action signals
can also be used for fetching the checkpoint information
programmatically instead of printing to the debug log.
This commit is contained in:
Nirbheek Chauhan 2019-06-21 18:17:13 +05:30
parent 5524137d7e
commit 6ccf59ec06
2 changed files with 209 additions and 54 deletions

View file

@ -75,6 +75,10 @@ enum
/* actions */
SIGNAL_GET_LIVE_OBJECTS,
SIGNAL_LOG_LIVE_OBJECTS,
SIGNAL_ACTIVITY_START_TRACKING,
SIGNAL_ACTIVITY_GET_CHECKPOINT,
SIGNAL_ACTIVITY_LOG_CHECKPOINT,
SIGNAL_ACTIVITY_STOP_TRACKING,
LAST_SIGNAL
};
@ -89,13 +93,16 @@ G_DEFINE_TYPE_WITH_CODE (GstLeaksTracer, gst_leaks_tracer,
static GstStructure *gst_leaks_tracer_get_live_objects (GstLeaksTracer * self);
static void gst_leaks_tracer_log_live_objects (GstLeaksTracer * self);
static void gst_leaks_tracer_activity_start_tracking (GstLeaksTracer * self);
static GstStructure *gst_leaks_tracer_activity_get_checkpoint (GstLeaksTracer *
self);
static void gst_leaks_tracer_activity_log_checkpoint (GstLeaksTracer * self);
static void gst_leaks_tracer_activity_stop_tracking (GstLeaksTracer * self);
static GstTracerRecord *tr_alive;
static GstTracerRecord *tr_refings;
#ifdef G_OS_UNIX
static GstTracerRecord *tr_added = NULL;
static GstTracerRecord *tr_removed = NULL;
#endif /* G_OS_UNIX */
static GQueue instances = G_QUEUE_INIT;
static guint gst_leaks_tracer_signals[LAST_SIGNAL] = { 0 };
@ -292,7 +299,6 @@ should_handle_object_type (GstLeaksTracer * self, GType object_type)
return FALSE;
}
#ifdef G_OS_UNIX
/* The object may be destroyed when we log it using the checkpointing system so
* we have to save its type name */
typedef struct
@ -321,7 +327,6 @@ object_log_free (ObjectLog * obj)
{
g_free (obj);
}
#endif /* G_OS_UNIX */
static void
handle_object_destroyed (GstLeaksTracer * self, gpointer object)
@ -335,10 +340,8 @@ handle_object_destroyed (GstLeaksTracer * self, gpointer object)
}
g_hash_table_remove (self->objects, object);
#ifdef G_OS_UNIX
if (self->removed)
g_hash_table_add (self->removed, object_log_new (object));
#endif /* G_OS_UNIX */
out:
GST_OBJECT_UNLOCK (self);
}
@ -382,10 +385,8 @@ handle_object_created (GstLeaksTracer * self, gpointer object, GType type,
g_hash_table_insert (self->objects, object, infos);
#ifdef G_OS_UNIX
if (self->added)
g_hash_table_add (self->added, object_log_new (object));
#endif /* G_OS_UNIX */
GST_OBJECT_UNLOCK (self);
}
@ -762,51 +763,17 @@ sig_usr1_handler (G_GNUC_UNUSED int signal)
g_queue_foreach (&instances, (GFunc) gst_leaks_tracer_log_live_objects, NULL);
}
static void
log_checkpoint (GHashTable * hash, GstTracerRecord * record)
{
GHashTableIter iter;
gpointer o;
g_hash_table_iter_init (&iter, hash);
while (g_hash_table_iter_next (&iter, &o, NULL)) {
ObjectLog *obj = o;
gst_tracer_record_log (record, obj->type_name, obj->object);
}
}
static void
do_checkpoint (GstLeaksTracer * self)
{
GST_TRACE_OBJECT (self, "listing objects created since last checkpoint");
log_checkpoint (self->added, tr_added);
GST_TRACE_OBJECT (self, "listing objects removed since last checkpoint");
log_checkpoint (self->removed, tr_removed);
g_hash_table_remove_all (self->added);
g_hash_table_remove_all (self->removed);
}
static void
sig_usr2_handler_foreach (gpointer data, gpointer user_data)
{
GstLeaksTracer *tracer = data;
GST_OBJECT_LOCK (tracer);
if (!tracer->added) {
GST_TRACE_OBJECT (tracer, "First checkpoint, start tracking objects");
tracer->added = g_hash_table_new_full (NULL, NULL,
(GDestroyNotify) object_log_free, NULL);
tracer->removed = g_hash_table_new_full (NULL, NULL,
(GDestroyNotify) object_log_free, NULL);
gst_leaks_tracer_activity_start_tracking (tracer);
} else {
do_checkpoint (tracer);
gst_leaks_tracer_activity_log_checkpoint (tracer);
}
GST_OBJECT_UNLOCK (tracer);
}
static void
@ -818,14 +785,6 @@ sig_usr2_handler (G_GNUC_UNUSED int signal)
static void
setup_signals (void)
{
tr_added = gst_tracer_record_new ("object-added.class",
RECORD_FIELD_TYPE_NAME, RECORD_FIELD_ADDRESS, NULL);
GST_OBJECT_FLAG_SET (tr_added, GST_OBJECT_FLAG_MAY_BE_LEAKED);
tr_removed = gst_tracer_record_new ("object-removed.class",
RECORD_FIELD_TYPE_NAME, RECORD_FIELD_ADDRESS, NULL);
GST_OBJECT_FLAG_SET (tr_removed, GST_OBJECT_FLAG_MAY_BE_LEAKED);
signal (SIGUSR1, sig_usr1_handler);
signal (SIGUSR2, sig_usr2_handler);
}
@ -859,6 +818,102 @@ gst_leaks_tracer_log_live_objects (GstLeaksTracer * self)
GST_OBJECT_UNLOCK (self);
}
static void
gst_leaks_tracer_activity_start_tracking (GstLeaksTracer * self)
{
GST_OBJECT_LOCK (self);
if (self->added) {
GST_ERROR_OBJECT (self, "tracking is already in progress");
return;
}
self->added = g_hash_table_new_full (NULL, NULL,
(GDestroyNotify) object_log_free, NULL);
self->removed = g_hash_table_new_full (NULL, NULL,
(GDestroyNotify) object_log_free, NULL);
GST_OBJECT_UNLOCK (self);
}
/* When @ret is %NULL, this simply logs the activities */
static void
process_checkpoint (GstTracerRecord * record, const gchar * record_type,
GHashTable * hash, GValue * ret)
{
GHashTableIter iter;
gpointer o;
g_hash_table_iter_init (&iter, hash);
while (g_hash_table_iter_next (&iter, &o, NULL)) {
ObjectLog *obj = o;
if (!ret) {
/* log to the debug log */
gst_tracer_record_log (record, obj->type_name, obj->object);
} else {
GValue s_value = G_VALUE_INIT;
GValue addr_value = G_VALUE_INIT;
gchar *address = g_strdup_printf ("%p", obj->object);
GstStructure *s = gst_structure_new_empty (record_type);
/* copy type_name because it's owned by @obj */
gst_structure_set (s, "type-name", G_TYPE_STRING, obj->type_name, NULL);
/* avoid copy of @address */
g_value_init (&addr_value, G_TYPE_STRING);
g_value_take_string (&addr_value, address);
gst_structure_take_value (s, "address", &addr_value);
/* avoid copy of the structure */
g_value_init (&s_value, GST_TYPE_STRUCTURE);
g_value_take_boxed (&s_value, s);
gst_value_list_append_and_take_value (ret, &s_value);
}
}
}
static GstStructure *
gst_leaks_tracer_activity_get_checkpoint (GstLeaksTracer * self)
{
GValue added = G_VALUE_INIT;
GValue removed = G_VALUE_INIT;
GstStructure *s = gst_structure_new_empty ("activity-checkpoint");
g_value_init (&added, GST_TYPE_LIST);
g_value_init (&removed, GST_TYPE_LIST);
GST_OBJECT_LOCK (self);
process_checkpoint (tr_added, "objects-created", self->added, &added);
process_checkpoint (tr_removed, "objects-removed", self->removed, &removed);
g_hash_table_remove_all (self->added);
g_hash_table_remove_all (self->removed);
GST_OBJECT_UNLOCK (self);
gst_structure_take_value (s, "objects-created-list", &added);
gst_structure_take_value (s, "objects-removed-list", &removed);
return s;
}
static void
gst_leaks_tracer_activity_log_checkpoint (GstLeaksTracer * self)
{
GST_OBJECT_LOCK (self);
GST_TRACE_OBJECT (self, "listing objects created since last checkpoint");
process_checkpoint (tr_added, NULL, self->added, NULL);
GST_TRACE_OBJECT (self, "listing objects removed since last checkpoint");
process_checkpoint (tr_removed, NULL, self->removed, NULL);
g_hash_table_remove_all (self->added);
g_hash_table_remove_all (self->removed);
GST_OBJECT_UNLOCK (self);
}
static void
gst_leaks_tracer_activity_stop_tracking (GstLeaksTracer * self)
{
GST_OBJECT_LOCK (self);
g_clear_pointer (&self->added, g_hash_table_destroy);
g_clear_pointer (&self->removed, g_hash_table_destroy);
GST_OBJECT_UNLOCK (self);
}
static void
gst_leaks_tracer_class_init (GstLeaksTracerClass * klass)
{
@ -877,6 +932,14 @@ gst_leaks_tracer_class_init (GstLeaksTracerClass * klass)
RECORD_FIELD_DESC, RECORD_FIELD_REF_COUNT, RECORD_FIELD_TRACE, NULL);
GST_OBJECT_FLAG_SET (tr_alive, GST_OBJECT_FLAG_MAY_BE_LEAKED);
tr_added = gst_tracer_record_new ("object-added.class",
RECORD_FIELD_TYPE_NAME, RECORD_FIELD_ADDRESS, NULL);
GST_OBJECT_FLAG_SET (tr_added, GST_OBJECT_FLAG_MAY_BE_LEAKED);
tr_removed = gst_tracer_record_new ("object-removed.class",
RECORD_FIELD_TYPE_NAME, RECORD_FIELD_ADDRESS, NULL);
GST_OBJECT_FLAG_SET (tr_removed, GST_OBJECT_FLAG_MAY_BE_LEAKED);
if (g_getenv ("GST_LEAKS_TRACER_SIG"))
setup_signals ();
@ -934,6 +997,94 @@ gst_leaks_tracer_class_init (GstLeaksTracerClass * klass)
G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION, G_STRUCT_OFFSET (GstLeaksTracerClass,
log_live_objects), NULL, NULL, NULL, G_TYPE_NONE, 0, G_TYPE_NONE);
/**
* GstLeaksTracer:::activity-start-tracking
* @leakstracer: the leaks tracer object to emit this signal on
*
* Start storing information about all objects that are being created or
* removed. Call `stop-tracking` to stop.
*
* NOTE: You do not need to call this to use the *-live-objects action
* signals listed above.
*
* Since: 1.18
*/
gst_leaks_tracer_signals[SIGNAL_ACTIVITY_START_TRACKING] =
g_signal_new ("activity-start-tracking", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION, G_STRUCT_OFFSET (GstLeaksTracerClass,
activity_start_tracking), NULL, NULL, NULL, G_TYPE_NONE, 0,
G_TYPE_NONE);
/**
* GstLeaksTracer:::activity-get-checkpoint
* @leakstracer: the leaks tracer object to emit this signal on
*
* You must call this after calling `activity-start-tracking` and you should
* call `activity-stop-tracking` when you are done tracking.
*
* Returns a #GstStructure with two fields: `"objects-created-list"` and
* `"objects-removed-list"`, each of which is a #GValue of type #GST_TYPE_LIST
* containing all objects that were created/removed since the last
* checkpoint, or since tracking started if this is the first checkpoint.
*
* The list elements are in order of creation/removal. Each list element is
* a #GValue containing a #GstStructure with the following fields:
*
* `type-name`: a string representing the type of the object
* `address`: a string representing the address of the object; the object
* itself cannot be returned since we don't own it and it may be
* freed at any moment, or it may already have been freed
*
* Returns: (transfer full): a newly-allocated #GstStructure
*
* Since: 1.18
*/
gst_leaks_tracer_signals[SIGNAL_ACTIVITY_GET_CHECKPOINT] =
g_signal_new ("activity-get-checkpoint", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION, G_STRUCT_OFFSET (GstLeaksTracerClass,
activity_get_checkpoint), NULL, NULL, NULL, GST_TYPE_STRUCTURE, 0,
G_TYPE_NONE);
/**
* GstLeaksTracer:::activity-log-checkpoint
* @leakstracer: the leaks tracer object to emit this signal on
*
* You must call this after calling `activity-start-tracking` and you should
* call `activity-stop-tracking` when you are done tracking.
*
* List all objects that were created or removed since the last checkpoint,
* or since tracking started if this is the first checkpoint.
*
* This action signal is equivalent to `activity-get-checkpoint` except that
* the checkpoint data will be printed to the debug log under `GST_TRACER:7`.
*
* Since: 1.18
*/
gst_leaks_tracer_signals[SIGNAL_ACTIVITY_LOG_CHECKPOINT] =
g_signal_new ("activity-log-checkpoint", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION, G_STRUCT_OFFSET (GstLeaksTracerClass,
activity_log_checkpoint), NULL, NULL, NULL, G_TYPE_NONE, 0,
G_TYPE_NONE);
/**
* GstLeaksTracer:::activity-stop-tracking
* @leakstracer: the leaks tracer object to emit this signal on
*
* Stop tracking all objects that are being created or removed, undoes the
* effects of the `start-tracking` signal.
*
* Since: 1.18
*/
gst_leaks_tracer_signals[SIGNAL_ACTIVITY_STOP_TRACKING] =
g_signal_new ("activity-stop-tracking", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION, G_STRUCT_OFFSET (GstLeaksTracerClass,
activity_stop_tracking), NULL, NULL, NULL, G_TYPE_NONE, 0,
G_TYPE_NONE);
klass->get_live_objects = gst_leaks_tracer_get_live_objects;
klass->log_live_objects = gst_leaks_tracer_log_live_objects;
klass->activity_start_tracking = gst_leaks_tracer_activity_start_tracking;
klass->activity_get_checkpoint = gst_leaks_tracer_activity_get_checkpoint;
klass->activity_log_checkpoint = gst_leaks_tracer_activity_log_checkpoint;
klass->activity_stop_tracking = gst_leaks_tracer_activity_stop_tracking;
}

View file

@ -78,8 +78,12 @@ struct _GstLeaksTracerClass {
GstTracerClass parent_class;
/* actions */
GstStructure * (*get_live_objects) (GstLeaksTracer *tracer);
void (*log_live_objects) (GstLeaksTracer *tracer);
GstStructure * (*get_live_objects) (GstLeaksTracer *tracer);
void (*log_live_objects) (GstLeaksTracer *tracer);
void (*activity_start_tracking) (GstLeaksTracer *tracer);
GstStructure * (*activity_get_checkpoint) (GstLeaksTracer *tracer);
void (*activity_log_checkpoint) (GstLeaksTracer *tracer);
void (*activity_stop_tracking) (GstLeaksTracer *tracer);
};
G_GNUC_INTERNAL GType gst_leaks_tracer_get_type (void);