diff options
| author | Edward Hervey <edward@centricular.com> | 2017-12-05 17:28:55 +0100 |
|---|---|---|
| committer | Edward Hervey <bilboed@bilboed.com> | 2017-12-05 18:19:32 +0100 |
| commit | e5c15f6b9605a1e682a60ea1bfadae831e651a41 (patch) | |
| tree | 5004ecda8f202da1cbf1f16a0fcdca52eb88e90d | |
| parent | 16d9954dd5a294f0a1e320b37e2582413cc516a8 (diff) | |
utils: Never return a group_id of 0, add GST_GROUP_ID_INVALID
Various plugins use special values (0 or G_MAXUINT32) as an
invalid/unset group_id, but nothing guarantees a groupid won't have
that value.
Instead define a value which group_id will never have and make
gst_group_id_next() always return a value different from that.
API: GST_GROUP_ID_INVALID
| -rw-r--r-- | docs/gst/gstreamer-sections.txt | 1 | ||||
| -rw-r--r-- | gst/gstutils.c | 12 | ||||
| -rw-r--r-- | gst/gstutils.h | 12 |
3 files changed, 23 insertions, 2 deletions
diff --git a/docs/gst/gstreamer-sections.txt b/docs/gst/gstreamer-sections.txt index 6385ca67e..52443e18f 100644 --- a/docs/gst/gstreamer-sections.txt +++ b/docs/gst/gstreamer-sections.txt @@ -3571,6 +3571,7 @@ GFLOAT_FROM_LE GFLOAT_SWAP_LE_BE GFLOAT_TO_BE GFLOAT_TO_LE +GST_GROUP_ID_INVALID gst_guint64_to_gdouble gst_gdouble_to_guint64 diff --git a/gst/gstutils.c b/gst/gstutils.c index 143bed758..be45dec0f 100644 --- a/gst/gstutils.c +++ b/gst/gstutils.c @@ -4177,14 +4177,22 @@ gst_pad_get_stream (GstPad * pad) * This function is used to generate a new group-id for the * stream-start event. * + * This function never returns %GST_GROUP_ID_INVALID (which is 0) + * * Returns: A constantly incrementing unsigned integer, which might * overflow back to 0 at some point. */ guint gst_util_group_id_next (void) { - static gint counter = 0; - return g_atomic_int_add (&counter, 1); + static gint counter = 1; + gint ret = g_atomic_int_add (&counter, 1); + + /* Make sure we don't return GST_GROUP_ID_INVALID */ + if (G_UNLIKELY (ret == GST_GROUP_ID_INVALID)) + ret = g_atomic_int_add (&counter, 1); + + return ret; } /* Compute log2 of the passed 64-bit number by finding the highest set bit */ diff --git a/gst/gstutils.h b/gst/gstutils.h index e891f1b89..a9b9eee88 100644 --- a/gst/gstutils.h +++ b/gst/gstutils.h @@ -107,6 +107,18 @@ guint32 gst_util_seqnum_next (void); GST_EXPORT gint32 gst_util_seqnum_compare (guint32 s1, guint32 s2); +/** + * GST_GROUP_ID_INVALID: + * + * A value which is guaranteed to never be returned by + * gst_util_group_id_next(). + * + * Can be used as a default value in variables used to store group_id. + * + * Since: 1.14 + */ +#define GST_GROUP_ID_INVALID (0) + GST_EXPORT guint gst_util_group_id_next (void); |