Update to use the new pad builders for safely setting pad functions

Only two uses of unsafely setting the pad functions is left:
- fallbacksrc for overriding the chain function of the proxy pad of a
  ghost pad
- threadshare for overriding the pad functions after creationg, which
  probably needs some fixing at some point

2 files changed, 138 insertions, 76 deletions

diff --git a/utils/fallbackswitch/src/fallbacksrc.rs b/utils/fallbackswitch/src/fallbacksrc.rs
index 9883bb32f..1a9325c44 100644
--- a/utils/fallbackswitch/src/fallbacksrc.rs
+++ b/utils/fallbackswitch/src/fallbacksrc.rs
@@ -704,7 +704,11 @@ impl FallbackSrc {
         };
 
         input
-            .add_pad(&gst::GhostPad::new(Some("src"), &srcpad).unwrap())
+            .add_pad(
+                &gst::GhostPad::builder(Some("src"), gst::PadDirection::Src)
+                    .build_with_target(&srcpad)
+                    .unwrap(),
+            )
             .unwrap();
 
         Ok(input.upcast())
@@ -724,7 +728,11 @@ impl FallbackSrc {
 
         let srcpad = audiotestsrc.get_static_pad("src").unwrap();
         input
-            .add_pad(&gst::GhostPad::new(Some("src"), &srcpad).unwrap())
+            .add_pad(
+                &gst::GhostPad::builder(Some("src"), gst::PadDirection::Src)
+                    .build_with_target(&srcpad)
+                    .unwrap(),
+            )
             .unwrap();
 
         Ok(input.upcast())
@@ -772,22 +780,27 @@ impl FallbackSrc {
         let templ = element
             .get_pad_template(if is_audio { "audio" } else { "video" })
             .unwrap();
-        let ghostpad =
-            gst::GhostPad::from_template(Some(&templ.get_name()), &srcpad, &templ).unwrap();
-
-        element.add_pad(&ghostpad).unwrap();
+        let ghostpad = gst::GhostPad::builder_with_template(&templ, Some(&templ.get_name()))
+            .build_with_target(&srcpad)
+            .unwrap();
 
         let proxypad = ghostpad.get_internal().expect("no internal pad");
         let element_weak = element.downgrade();
-        proxypad.set_chain_function(move |pad, _parent, buffer| {
-            let element = match element_weak.upgrade() {
-                None => return Err(gst::FlowError::Flushing),
-                Some(element) => element,
-            };
+        // Safety: Nothing else can have a reference to the proxy pad yet apart from the ghost pad
+        // itself, so changing the chain function is still safe.
+        unsafe {
+            proxypad.set_chain_function(move |pad, _parent, buffer| {
+                let element = match element_weak.upgrade() {
+                    None => return Err(gst::FlowError::Flushing),
+                    Some(element) => element,
+                };
 
-            let src = FallbackSrc::from_instance(&element);
-            src.proxy_pad_chain(&element, pad, buffer)
-        });
+                let src = FallbackSrc::from_instance(&element);
+                src.proxy_pad_chain(&element, pad, buffer)
+            });
+        }
+
+        element.add_pad(&ghostpad).unwrap();
 
         Ok(Stream {
             fallback_input,
@@ -2215,7 +2228,9 @@ mod custom_source {
                 (element.get_pad_template("video_%u").unwrap(), name)
             };
 
-            let ghost_pad = gst::GhostPad::from_template(Some(&name), pad, &templ).unwrap();
+            let ghost_pad = gst::GhostPad::builder_with_template(&templ, Some(&name))
+                .build_with_target(pad)
+                .unwrap();
 
             let stream = Stream {
                 source_pad: pad.clone(),
diff --git a/utils/togglerecord/src/togglerecord.rs b/utils/togglerecord/src/togglerecord.rs
index 201fce387..146aa3a0b 100644
--- a/utils/togglerecord/src/togglerecord.rs
+++ b/utils/togglerecord/src/togglerecord.rs
@@ -362,59 +362,6 @@ lazy_static! {
 }
 
 impl ToggleRecord {
-    fn set_pad_functions(sinkpad: &gst::Pad, srcpad: &gst::Pad) {
-        sinkpad.set_chain_function(|pad, parent, buffer| {
-            ToggleRecord::catch_panic_pad_function(
-                parent,
-                || Err(gst::FlowError::Error),
-                |togglerecord, element| togglerecord.sink_chain(pad, element, buffer),
-            )
-        });
-        sinkpad.set_event_function(|pad, parent, event| {
-            ToggleRecord::catch_panic_pad_function(
-                parent,
-                || false,
-                |togglerecord, element| togglerecord.sink_event(pad, element, event),
-            )
-        });
-        sinkpad.set_query_function(|pad, parent, query| {
-            ToggleRecord::catch_panic_pad_function(
-                parent,
-                || false,
-                |togglerecord, element| togglerecord.sink_query(pad, element, query),
-            )
-        });
-        sinkpad.set_iterate_internal_links_function(|pad, parent| {
-            ToggleRecord::catch_panic_pad_function(
-                parent,
-                || gst::Iterator::from_vec(vec![]),
-                |togglerecord, element| togglerecord.iterate_internal_links(pad, element),
-            )
-        });
-
-        srcpad.set_event_function(|pad, parent, event| {
-            ToggleRecord::catch_panic_pad_function(
-                parent,
-                || false,
-                |togglerecord, element| togglerecord.src_event(pad, element, event),
-            )
-        });
-        srcpad.set_query_function(|pad, parent, query| {
-            ToggleRecord::catch_panic_pad_function(
-                parent,
-                || false,
-                |togglerecord, element| togglerecord.src_query(pad, element, query),
-            )
-        });
-        srcpad.set_iterate_internal_links_function(|pad, parent| {
-            ToggleRecord::catch_panic_pad_function(
-                parent,
-                || gst::Iterator::from_vec(vec![]),
-                |togglerecord, element| togglerecord.iterate_internal_links(pad, element),
-            )
-        });
-    }
-
     fn handle_main_stream<T: HandleData>(
         &self,
         element: &gst::Element,
@@ -1537,11 +1484,61 @@ impl ObjectSubclass for ToggleRecord {
 
     fn with_class(klass: &subclass::simple::ClassStruct<Self>) -> Self {
         let templ = klass.get_pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::from_template(&templ, Some("sink"));
-        let templ = klass.get_pad_template("src").unwrap();
-        let srcpad = gst::Pad::from_template(&templ, Some("src"));
+        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+            .chain_function(|pad, parent, buffer| {
+                ToggleRecord::catch_panic_pad_function(
+                    parent,
+                    || Err(gst::FlowError::Error),
+                    |togglerecord, element| togglerecord.sink_chain(pad, element, buffer),
+                )
+            })
+            .event_function(|pad, parent, event| {
+                ToggleRecord::catch_panic_pad_function(
+                    parent,
+                    || false,
+                    |togglerecord, element| togglerecord.sink_event(pad, element, event),
+                )
+            })
+            .query_function(|pad, parent, query| {
+                ToggleRecord::catch_panic_pad_function(
+                    parent,
+                    || false,
+                    |togglerecord, element| togglerecord.sink_query(pad, element, query),
+                )
+            })
+            .iterate_internal_links_function(|pad, parent| {
+                ToggleRecord::catch_panic_pad_function(
+                    parent,
+                    || gst::Iterator::from_vec(vec![]),
+                    |togglerecord, element| togglerecord.iterate_internal_links(pad, element),
+                )
+            })
+            .build();
 
-        ToggleRecord::set_pad_functions(&sinkpad, &srcpad);
+        let templ = klass.get_pad_template("src").unwrap();
+        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+            .event_function(|pad, parent, event| {
+                ToggleRecord::catch_panic_pad_function(
+                    parent,
+                    || false,
+                    |togglerecord, element| togglerecord.src_event(pad, element, event),
+                )
+            })
+            .query_function(|pad, parent, query| {
+                ToggleRecord::catch_panic_pad_function(
+                    parent,
+                    || false,
+                    |togglerecord, element| togglerecord.src_query(pad, element, query),
+                )
+            })
+            .iterate_internal_links_function(|pad, parent| {
+                ToggleRecord::catch_panic_pad_function(
+                    parent,
+                    || gst::Iterator::from_vec(vec![]),
+                    |togglerecord, element| togglerecord.iterate_internal_links(pad, element),
+                )
+            })
+            .build();
 
         let main_stream = Stream::new(sinkpad, srcpad);
 
@@ -1734,12 +1731,62 @@ impl ElementImpl for ToggleRecord {
         *pad_count += 1;
 
         let templ = element.get_pad_template("sink_%u").unwrap();
-        let sinkpad = gst::Pad::from_template(&templ, Some(format!("sink_{}", id).as_str()));
+        let sinkpad =
+            gst::Pad::builder_with_template(&templ, Some(format!("sink_{}", id).as_str()))
+                .chain_function(|pad, parent, buffer| {
+                    ToggleRecord::catch_panic_pad_function(
+                        parent,
+                        || Err(gst::FlowError::Error),
+                        |togglerecord, element| togglerecord.sink_chain(pad, element, buffer),
+                    )
+                })
+                .event_function(|pad, parent, event| {
+                    ToggleRecord::catch_panic_pad_function(
+                        parent,
+                        || false,
+                        |togglerecord, element| togglerecord.sink_event(pad, element, event),
+                    )
+                })
+                .query_function(|pad, parent, query| {
+                    ToggleRecord::catch_panic_pad_function(
+                        parent,
+                        || false,
+                        |togglerecord, element| togglerecord.sink_query(pad, element, query),
+                    )
+                })
+                .iterate_internal_links_function(|pad, parent| {
+                    ToggleRecord::catch_panic_pad_function(
+                        parent,
+                        || gst::Iterator::from_vec(vec![]),
+                        |togglerecord, element| togglerecord.iterate_internal_links(pad, element),
+                    )
+                })
+                .build();
 
         let templ = element.get_pad_template("src_%u").unwrap();
-        let srcpad = gst::Pad::from_template(&templ, Some(format!("src_{}", id).as_str()));
-
-        ToggleRecord::set_pad_functions(&sinkpad, &srcpad);
+        let srcpad = gst::Pad::builder_with_template(&templ, Some(format!("src_{}", id).as_str()))
+            .event_function(|pad, parent, event| {
+                ToggleRecord::catch_panic_pad_function(
+                    parent,
+                    || false,
+                    |togglerecord, element| togglerecord.src_event(pad, element, event),
+                )
+            })
+            .query_function(|pad, parent, query| {
+                ToggleRecord::catch_panic_pad_function(
+                    parent,
+                    || false,
+                    |togglerecord, element| togglerecord.src_query(pad, element, query),
+                )
+            })
+            .iterate_internal_links_function(|pad, parent| {
+                ToggleRecord::catch_panic_pad_function(
+                    parent,
+                    || gst::Iterator::from_vec(vec![]),
+                    |togglerecord, element| togglerecord.iterate_internal_links(pad, element),
+                )
+            })
+            .build();
 
         sinkpad.set_active(true).unwrap();
         srcpad.set_active(true).unwrap();