gstreamer-rs/gstreamer/src/pad.rs

// Copyright (C) 2017 Sebastian Dröge <sebastian@centricular.com>
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use miniobject::MiniObject;
use BinFlags;
use Buffer;
use BufferList;
use Event;
use FlowError;
use FlowReturn;
use FlowSuccess;
use Format;
use FormattedValue;
use GenericFormattedValue;
use LoggableError;
use Pad;
use PadLinkCheck;
use PadLinkError;
use PadLinkReturn;
use PadLinkSuccess;
use PadProbeReturn;
use PadProbeType;
use Query;
use QueryRef;
use SpecificFormattedValue;
use StaticPadTemplate;

use std::cell::RefCell;
use std::mem;
use std::ptr;

use glib;
use glib::object::{Cast, IsA};
use glib::translate::{
    from_glib, from_glib_borrow, from_glib_full, from_glib_none, mut_override, FromGlib,
    FromGlibPtrBorrow, ToGlib, ToGlibPtr,
};
use glib::StaticType;
use glib_sys;
use glib_sys::gpointer;

use libc;

use gst_sys;

impl Pad {
    pub fn new_from_static_template(templ: &StaticPadTemplate, name: Option<&str>) -> Pad {
        assert_initialized_main_thread!();
        unsafe {
            from_glib_none(gst_sys::gst_pad_new_from_static_template(
                mut_override(templ.to_glib_none().0),
                name.to_glib_none().0,
            ))
        }
    }
}

#[derive(Debug, PartialEq, Eq)]
pub struct PadProbeId(libc::c_ulong);

impl ToGlib for PadProbeId {
    type GlibType = libc::c_ulong;

    fn to_glib(&self) -> libc::c_ulong {
        self.0
    }
}

impl FromGlib<libc::c_ulong> for PadProbeId {
    fn from_glib(val: libc::c_ulong) -> PadProbeId {
        skip_assert_initialized!();
        assert_ne!(val, 0);
        PadProbeId(val)
    }
}

#[derive(Debug)]
pub struct PadProbeInfo<'a> {
    pub mask: PadProbeType,
    pub id: PadProbeId,
    pub offset: u64,
    pub size: u32,
    pub data: Option<PadProbeData<'a>>,
    pub flow_ret: FlowReturn,
}

#[derive(Debug)]
pub enum PadProbeData<'a> {
    Buffer(Buffer),
    BufferList(BufferList),
    Query(&'a mut QueryRef),
    Event(Event),
    #[doc(hidden)]
    __Unknown(*mut gst_sys::GstMiniObject),
}

unsafe impl<'a> Send for PadProbeData<'a> {}
unsafe impl<'a> Sync for PadProbeData<'a> {}

#[derive(Debug)]
pub struct StreamLock(Pad);
impl Drop for StreamLock {
    fn drop(&mut self) {
        unsafe {
            let pad: *mut gst_sys::GstPad = self.0.to_glib_none().0;
            glib_sys::g_rec_mutex_unlock(&mut (*pad).stream_rec_lock);
        }
    }
}

pub trait PadExtManual: 'static {
    fn add_probe<F>(&self, mask: PadProbeType, func: F) -> Option<PadProbeId>
    where
        F: Fn(&Self, &mut PadProbeInfo) -> PadProbeReturn + Send + Sync + 'static;
    fn remove_probe(&self, id: PadProbeId);

    fn chain(&self, buffer: Buffer) -> Result<FlowSuccess, FlowError>;
    fn push(&self, buffer: Buffer) -> Result<FlowSuccess, FlowError>;

    fn chain_list(&self, list: BufferList) -> Result<FlowSuccess, FlowError>;
    fn push_list(&self, list: BufferList) -> Result<FlowSuccess, FlowError>;

    fn pull_range(&self, offset: u64, size: u32) -> Result<Buffer, FlowError>;
    fn get_range(&self, offset: u64, size: u32) -> Result<Buffer, FlowError>;

    fn peer_query(&self, query: &mut QueryRef) -> bool;
    fn query(&self, query: &mut QueryRef) -> bool;
    fn query_default<P: IsA<::Object>>(&self, parent: Option<&P>, query: &mut QueryRef) -> bool;
    fn proxy_query_caps(&self, query: &mut QueryRef) -> bool;
    fn proxy_query_accept_caps(&self, query: &mut QueryRef) -> bool;

    fn event_default<P: IsA<::Object>>(&self, parent: Option<&P>, event: Event) -> bool;
    fn push_event(&self, event: Event) -> bool;
    fn send_event(&self, event: Event) -> bool;

    fn get_last_flow_return(&self) -> Result<FlowSuccess, FlowError>;

    fn iterate_internal_links(&self) -> ::Iterator<Pad>;
    fn iterate_internal_links_default<P: IsA<::Object>>(
        &self,
        parent: Option<&P>,
    ) -> ::Iterator<Pad>;

    fn link<P: IsA<Pad>>(&self, sinkpad: &P) -> Result<PadLinkSuccess, PadLinkError>;
    fn link_full<P: IsA<Pad>>(
        &self,
        sinkpad: &P,
        flags: PadLinkCheck,
    ) -> Result<PadLinkSuccess, PadLinkError>;

    fn stream_lock(&self) -> StreamLock;

    fn set_activate_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>) -> Result<(), LoggableError> + Send + Sync + 'static;

    fn set_activatemode_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, ::PadMode, bool) -> Result<(), LoggableError>
            + Send
            + Sync
            + 'static;

    fn set_chain_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, ::Buffer) -> Result<FlowSuccess, FlowError>
            + Send
            + Sync
            + 'static;

    fn set_chain_list_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, ::BufferList) -> Result<FlowSuccess, FlowError>
            + Send
            + Sync
            + 'static;

    fn set_event_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, ::Event) -> bool + Send + Sync + 'static;

    fn set_event_full_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, ::Event) -> Result<FlowSuccess, FlowError>
            + Send
            + Sync
            + 'static;

    fn set_getrange_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, u64, u32) -> Result<::Buffer, ::FlowError>
            + Send
            + Sync
            + 'static;

    fn set_iterate_internal_links_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>) -> ::Iterator<Pad> + Send + Sync + 'static;

    fn set_link_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, &Pad) -> Result<::PadLinkSuccess, ::PadLinkError>
            + Send
            + Sync
            + 'static;

    fn set_query_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, &mut ::QueryRef) -> bool + Send + Sync + 'static;

    fn set_unlink_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>) + Send + Sync + 'static;

    fn start_task<F: FnMut() + Send + 'static>(&self, func: F) -> Result<(), glib::BoolError>;

    fn peer_query_convert<V: Into<GenericFormattedValue>, U: SpecificFormattedValue>(
        &self,
        src_val: V,
    ) -> Option<U>;
    fn peer_query_convert_generic<V: Into<GenericFormattedValue>>(
        &self,
        src_val: V,
        dest_format: Format,
    ) -> Option<GenericFormattedValue>;

    fn peer_query_duration<T: SpecificFormattedValue>(&self) -> Option<T>;
    fn peer_query_duration_generic(&self, format: Format) -> Option<GenericFormattedValue>;

    fn peer_query_position<T: SpecificFormattedValue>(&self) -> Option<T>;
    fn peer_query_position_generic(&self, format: Format) -> Option<GenericFormattedValue>;

    fn query_convert<V: Into<GenericFormattedValue>, U: SpecificFormattedValue>(
        &self,
        src_val: V,
    ) -> Option<U>;
    fn query_convert_generic<V: Into<GenericFormattedValue>>(
        &self,
        src_val: V,
        dest_format: Format,
    ) -> Option<GenericFormattedValue>;

    fn query_duration<T: SpecificFormattedValue>(&self) -> Option<T>;
    fn query_duration_generic(&self, format: Format) -> Option<GenericFormattedValue>;

    fn query_position<T: SpecificFormattedValue>(&self) -> Option<T>;
    fn query_position_generic(&self, format: Format) -> Option<GenericFormattedValue>;

    fn get_mode(&self) -> ::PadMode;

    fn sticky_events_foreach<F: FnMut(Event) -> Result<Option<Event>, Option<Event>>>(
        &self,
        func: F,
    );

    fn store_sticky_event(&self, event: &Event) -> Result<FlowSuccess, FlowError>;

    fn set_bin_flags(&self, flags: BinFlags);

    fn unset_bin_flags(&self, flags: BinFlags);

    fn get_bin_flags(&self) -> BinFlags;
}

impl<O: IsA<Pad>> PadExtManual for O {
    fn add_probe<F>(&self, mask: PadProbeType, func: F) -> Option<PadProbeId>
    where
        F: Fn(&Self, &mut PadProbeInfo) -> PadProbeReturn + Send + Sync + 'static,
    {
        unsafe {
            let func_box: Box<F> = Box::new(func);
            let id = gst_sys::gst_pad_add_probe(
                self.as_ref().to_glib_none().0,
                mask.to_glib(),
                Some(trampoline_pad_probe::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );

            if id == 0 {
                None
            } else {
                Some(from_glib(id))
            }
        }
    }

    fn remove_probe(&self, id: PadProbeId) {
        unsafe {
            gst_sys::gst_pad_remove_probe(self.as_ref().to_glib_none().0, id.to_glib());
        }
    }

    fn chain(&self, buffer: Buffer) -> Result<FlowSuccess, FlowError> {
        unsafe {
            FlowReturn::from_glib(gst_sys::gst_pad_chain(
                self.as_ref().to_glib_none().0,
                buffer.into_ptr(),
            ))
            .into_result()
        }
    }

    fn push(&self, buffer: Buffer) -> Result<FlowSuccess, FlowError> {
        unsafe {
            FlowReturn::from_glib(gst_sys::gst_pad_push(
                self.as_ref().to_glib_none().0,
                buffer.into_ptr(),
            ))
            .into_result()
        }
    }

    fn chain_list(&self, list: BufferList) -> Result<FlowSuccess, FlowError> {
        unsafe {
            FlowReturn::from_glib(gst_sys::gst_pad_chain_list(
                self.as_ref().to_glib_none().0,
                list.into_ptr(),
            ))
            .into_result()
        }
    }

    fn push_list(&self, list: BufferList) -> Result<FlowSuccess, FlowError> {
        unsafe {
            FlowReturn::from_glib(gst_sys::gst_pad_push_list(
                self.as_ref().to_glib_none().0,
                list.into_ptr(),
            ))
            .into_result()
        }
    }

    fn get_range(&self, offset: u64, size: u32) -> Result<Buffer, FlowError> {
        unsafe {
            let mut buffer = ptr::null_mut();
            let ret: FlowReturn = from_glib(gst_sys::gst_pad_get_range(
                self.as_ref().to_glib_none().0,
                offset,
                size,
                &mut buffer,
            ));
            ret.into_result_value(|| from_glib_full(buffer))
        }
    }

    fn pull_range(&self, offset: u64, size: u32) -> Result<Buffer, FlowError> {
        unsafe {
            let mut buffer = ptr::null_mut();
            let ret: FlowReturn = from_glib(gst_sys::gst_pad_pull_range(
                self.as_ref().to_glib_none().0,
                offset,
                size,
                &mut buffer,
            ));
            ret.into_result_value(|| from_glib_full(buffer))
        }
    }

    fn query(&self, query: &mut QueryRef) -> bool {
        unsafe {
            from_glib(gst_sys::gst_pad_query(
                self.as_ref().to_glib_none().0,
                query.as_mut_ptr(),
            ))
        }
    }

    fn peer_query(&self, query: &mut QueryRef) -> bool {
        unsafe {
            from_glib(gst_sys::gst_pad_peer_query(
                self.as_ref().to_glib_none().0,
                query.as_mut_ptr(),
            ))
        }
    }

    fn query_default<P: IsA<::Object>>(&self, parent: Option<&P>, query: &mut QueryRef) -> bool {
        skip_assert_initialized!();
        unsafe {
            from_glib(gst_sys::gst_pad_query_default(
                self.as_ref().to_glib_none().0,
                parent.map(|p| p.as_ref()).to_glib_none().0,
                query.as_mut_ptr(),
            ))
        }
    }

    fn proxy_query_accept_caps(&self, query: &mut QueryRef) -> bool {
        unsafe {
            from_glib(gst_sys::gst_pad_proxy_query_accept_caps(
                self.as_ref().to_glib_none().0,
                query.as_mut_ptr(),
            ))
        }
    }

    fn proxy_query_caps(&self, query: &mut QueryRef) -> bool {
        unsafe {
            from_glib(gst_sys::gst_pad_proxy_query_accept_caps(
                self.as_ref().to_glib_none().0,
                query.as_mut_ptr(),
            ))
        }
    }

    fn event_default<P: IsA<::Object>>(&self, parent: Option<&P>, event: Event) -> bool {
        skip_assert_initialized!();
        unsafe {
            from_glib(gst_sys::gst_pad_event_default(
                self.as_ref().to_glib_none().0,
                parent.map(|p| p.as_ref()).to_glib_none().0,
                event.into_ptr(),
            ))
        }
    }

    fn push_event(&self, event: Event) -> bool {
        unsafe {
            from_glib(gst_sys::gst_pad_push_event(
                self.as_ref().to_glib_none().0,
                event.into_ptr(),
            ))
        }
    }

    fn send_event(&self, event: Event) -> bool {
        unsafe {
            from_glib(gst_sys::gst_pad_send_event(
                self.as_ref().to_glib_none().0,
                event.into_ptr(),
            ))
        }
    }

    fn get_last_flow_return(&self) -> Result<FlowSuccess, FlowError> {
        let ret: FlowReturn = unsafe {
            from_glib(gst_sys::gst_pad_get_last_flow_return(
                self.as_ref().to_glib_none().0,
            ))
        };
        ret.into_result()
    }

    fn iterate_internal_links(&self) -> ::Iterator<Pad> {
        unsafe {
            from_glib_full(gst_sys::gst_pad_iterate_internal_links(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    fn iterate_internal_links_default<P: IsA<::Object>>(
        &self,
        parent: Option<&P>,
    ) -> ::Iterator<Pad> {
        unsafe {
            from_glib_full(gst_sys::gst_pad_iterate_internal_links_default(
                self.as_ref().to_glib_none().0,
                parent.map(|p| p.as_ref()).to_glib_none().0,
            ))
        }
    }

    fn link<P: IsA<Pad>>(&self, sinkpad: &P) -> Result<PadLinkSuccess, PadLinkError> {
        let ret: PadLinkReturn = unsafe {
            from_glib(gst_sys::gst_pad_link(
                self.as_ref().to_glib_none().0,
                sinkpad.as_ref().to_glib_none().0,
            ))
        };
        ret.into_result()
    }

    fn link_full<P: IsA<Pad>>(
        &self,
        sinkpad: &P,
        flags: PadLinkCheck,
    ) -> Result<PadLinkSuccess, PadLinkError> {
        let ret: PadLinkReturn = unsafe {
            from_glib(gst_sys::gst_pad_link_full(
                self.as_ref().to_glib_none().0,
                sinkpad.as_ref().to_glib_none().0,
                flags.to_glib(),
            ))
        };
        ret.into_result()
    }

    fn stream_lock(&self) -> StreamLock {
        unsafe {
            let ptr: &mut gst_sys::GstPad = &mut *(self.as_ptr() as *mut _);
            glib_sys::g_rec_mutex_lock(&mut ptr.stream_rec_lock);
            StreamLock(from_glib_none(ptr as *mut gst_sys::GstPad))
        }
    }

    fn set_activate_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>) -> Result<(), LoggableError> + Send + Sync + 'static,
    {
        #[allow(clippy::type_complexity)]
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_activate_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_activate_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn set_activatemode_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, ::PadMode, bool) -> Result<(), LoggableError>
            + Send
            + Sync
            + 'static,
    {
        #[allow(clippy::type_complexity)]
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_activatemode_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_activatemode_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn set_chain_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, ::Buffer) -> Result<FlowSuccess, FlowError>
            + Send
            + Sync
            + 'static,
    {
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_chain_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_chain_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn set_chain_list_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, ::BufferList) -> Result<FlowSuccess, FlowError>
            + Send
            + Sync
            + 'static,
    {
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_chain_list_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_chain_list_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn set_event_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, ::Event) -> bool + Send + Sync + 'static,
    {
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_event_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_event_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn set_event_full_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, ::Event) -> Result<FlowSuccess, FlowError>
            + Send
            + Sync
            + 'static,
    {
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_event_full_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_event_full_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn set_getrange_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, u64, u32) -> Result<::Buffer, FlowError>
            + Send
            + Sync
            + 'static,
    {
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_getrange_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_getrange_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn set_iterate_internal_links_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>) -> ::Iterator<Pad> + Send + Sync + 'static,
    {
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_iterate_internal_links_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_iterate_internal_links_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn set_link_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, &Pad) -> Result<::PadLinkSuccess, ::PadLinkError>
            + Send
            + Sync
            + 'static,
    {
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_link_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_link_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn set_query_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>, &mut ::QueryRef) -> bool + Send + Sync + 'static,
    {
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_query_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_query_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn set_unlink_function<F>(&self, func: F)
    where
        F: Fn(&Self, Option<&::Object>) + Send + Sync + 'static,
    {
        unsafe {
            let func_box: Box<F> = Box::new(func);
            gst_sys::gst_pad_set_unlink_function_full(
                self.as_ref().to_glib_none().0,
                Some(trampoline_unlink_function::<Self, F>),
                Box::into_raw(func_box) as gpointer,
                Some(destroy_closure::<F>),
            );
        }
    }

    fn start_task<F: FnMut() + Send + 'static>(&self, func: F) -> Result<(), glib::BoolError> {
        unsafe {
            glib_result_from_gboolean!(
                gst_sys::gst_pad_start_task(
                    self.as_ref().to_glib_none().0,
                    Some(trampoline_pad_task::<F>),
                    into_raw_pad_task(func),
                    Some(destroy_closure_pad_task::<F>),
                ),
                "Failed to start pad task",
            )
        }
    }

    fn peer_query_convert<V: Into<GenericFormattedValue>, U: SpecificFormattedValue>(
        &self,
        src_val: V,
    ) -> Option<U> {
        let src_val = src_val.into();
        unsafe {
            let mut dest_val = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_peer_query_convert(
                self.as_ref().to_glib_none().0,
                src_val.get_format().to_glib(),
                src_val.to_raw_value(),
                U::get_default_format().to_glib(),
                dest_val.as_mut_ptr(),
            ));
            if ret {
                Some(U::from_raw(U::get_default_format(), dest_val.assume_init()))
            } else {
                None
            }
        }
    }

    fn peer_query_convert_generic<V: Into<GenericFormattedValue>>(
        &self,
        src_val: V,
        dest_format: Format,
    ) -> Option<GenericFormattedValue> {
        let src_val = src_val.into();
        unsafe {
            let mut dest_val = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_peer_query_convert(
                self.as_ref().to_glib_none().0,
                src_val.get_format().to_glib(),
                src_val.to_raw_value(),
                dest_format.to_glib(),
                dest_val.as_mut_ptr(),
            ));
            if ret {
                Some(GenericFormattedValue::new(
                    dest_format,
                    dest_val.assume_init(),
                ))
            } else {
                None
            }
        }
    }

    fn peer_query_duration<T: SpecificFormattedValue>(&self) -> Option<T> {
        unsafe {
            let mut duration = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_peer_query_duration(
                self.as_ref().to_glib_none().0,
                T::get_default_format().to_glib(),
                duration.as_mut_ptr(),
            ));
            if ret {
                Some(T::from_raw(T::get_default_format(), duration.assume_init()))
            } else {
                None
            }
        }
    }

    fn peer_query_duration_generic(&self, format: Format) -> Option<GenericFormattedValue> {
        unsafe {
            let mut duration = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_peer_query_duration(
                self.as_ref().to_glib_none().0,
                format.to_glib(),
                duration.as_mut_ptr(),
            ));
            if ret {
                Some(GenericFormattedValue::new(format, duration.assume_init()))
            } else {
                None
            }
        }
    }

    fn peer_query_position<T: SpecificFormattedValue>(&self) -> Option<T> {
        unsafe {
            let mut cur = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_peer_query_position(
                self.as_ref().to_glib_none().0,
                T::get_default_format().to_glib(),
                cur.as_mut_ptr(),
            ));
            if ret {
                Some(T::from_raw(T::get_default_format(), cur.assume_init()))
            } else {
                None
            }
        }
    }

    fn peer_query_position_generic(&self, format: Format) -> Option<GenericFormattedValue> {
        unsafe {
            let mut cur = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_peer_query_position(
                self.as_ref().to_glib_none().0,
                format.to_glib(),
                cur.as_mut_ptr(),
            ));
            if ret {
                Some(GenericFormattedValue::new(format, cur.assume_init()))
            } else {
                None
            }
        }
    }

    fn query_convert<V: Into<GenericFormattedValue>, U: SpecificFormattedValue>(
        &self,
        src_val: V,
    ) -> Option<U> {
        let src_val = src_val.into();

        unsafe {
            let mut dest_val = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_query_convert(
                self.as_ref().to_glib_none().0,
                src_val.get_format().to_glib(),
                src_val.to_raw_value(),
                U::get_default_format().to_glib(),
                dest_val.as_mut_ptr(),
            ));
            if ret {
                Some(U::from_raw(U::get_default_format(), dest_val.assume_init()))
            } else {
                None
            }
        }
    }

    fn query_convert_generic<V: Into<GenericFormattedValue>>(
        &self,
        src_val: V,
        dest_format: Format,
    ) -> Option<GenericFormattedValue> {
        let src_val = src_val.into();

        unsafe {
            let mut dest_val = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_query_convert(
                self.as_ref().to_glib_none().0,
                src_val.get_format().to_glib(),
                src_val.get_value(),
                dest_format.to_glib(),
                dest_val.as_mut_ptr(),
            ));
            if ret {
                Some(GenericFormattedValue::new(
                    dest_format,
                    dest_val.assume_init(),
                ))
            } else {
                None
            }
        }
    }

    fn query_duration<T: SpecificFormattedValue>(&self) -> Option<T> {
        unsafe {
            let mut duration = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_query_duration(
                self.as_ref().to_glib_none().0,
                T::get_default_format().to_glib(),
                duration.as_mut_ptr(),
            ));
            if ret {
                Some(T::from_raw(T::get_default_format(), duration.assume_init()))
            } else {
                None
            }
        }
    }

    fn query_duration_generic(&self, format: Format) -> Option<GenericFormattedValue> {
        unsafe {
            let mut duration = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_query_duration(
                self.as_ref().to_glib_none().0,
                format.to_glib(),
                duration.as_mut_ptr(),
            ));
            if ret {
                Some(GenericFormattedValue::new(format, duration.assume_init()))
            } else {
                None
            }
        }
    }

    fn query_position<T: SpecificFormattedValue>(&self) -> Option<T> {
        unsafe {
            let mut cur = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_query_position(
                self.as_ref().to_glib_none().0,
                T::get_default_format().to_glib(),
                cur.as_mut_ptr(),
            ));
            if ret {
                Some(T::from_raw(T::get_default_format(), cur.assume_init()))
            } else {
                None
            }
        }
    }

    fn query_position_generic(&self, format: Format) -> Option<GenericFormattedValue> {
        unsafe {
            let mut cur = mem::MaybeUninit::uninit();
            let ret = from_glib(gst_sys::gst_pad_query_position(
                self.as_ref().to_glib_none().0,
                format.to_glib(),
                cur.as_mut_ptr(),
            ));
            if ret {
                Some(GenericFormattedValue::new(format, cur.assume_init()))
            } else {
                None
            }
        }
    }

    fn get_mode(&self) -> ::PadMode {
        unsafe {
            let ptr: &gst_sys::GstPad = &*(self.as_ptr() as *const _);
            from_glib(ptr.mode)
        }
    }

    fn sticky_events_foreach<F: FnMut(Event) -> Result<Option<Event>, Option<Event>>>(
        &self,
        func: F,
    ) {
        unsafe extern "C" fn trampoline(
            _pad: *mut gst_sys::GstPad,
            event: *mut *mut gst_sys::GstEvent,
            user_data: glib_sys::gpointer,
        ) -> glib_sys::gboolean {
            let func =
                user_data as *mut &mut (dyn FnMut(Event) -> Result<Option<Event>, Option<Event>>);
            let res = (*func)(from_glib_full(*event));

            match res {
                Ok(Some(ev)) => {
                    *event = ev.into_ptr();
                    glib_sys::GTRUE
                }
                Err(Some(ev)) => {
                    *event = ev.into_ptr();
                    glib_sys::GFALSE
                }
                Ok(None) => {
                    *event = ptr::null_mut();
                    glib_sys::GTRUE
                }
                Err(None) => {
                    *event = ptr::null_mut();
                    glib_sys::GFALSE
                }
            }
        }

        unsafe {
            let mut func = func;
            let func_obj: &mut (dyn FnMut(Event) -> Result<Option<Event>, Option<Event>>) =
                &mut func;
            let func_ptr = &func_obj
                as *const &mut (dyn FnMut(Event) -> Result<Option<Event>, Option<Event>>)
                as glib_sys::gpointer;

            gst_sys::gst_pad_sticky_events_foreach(
                self.as_ref().to_glib_none().0,
                Some(trampoline),
                func_ptr,
            );
        }
    }

    fn store_sticky_event(&self, event: &Event) -> Result<FlowSuccess, FlowError> {
        let ret: FlowReturn = unsafe {
            from_glib(gst_sys::gst_pad_store_sticky_event(
                self.as_ref().to_glib_none().0,
                event.to_glib_none().0,
            ))
        };
        ret.into_result()
    }

    fn set_bin_flags(&self, flags: BinFlags) {
        unsafe {
            let ptr: *mut gst_sys::GstObject = self.as_ptr() as *mut _;
            let _guard = ::utils::MutexGuard::lock(&(*ptr).lock);
            (*ptr).flags |= flags.to_glib();
        }
    }

    fn unset_bin_flags(&self, flags: BinFlags) {
        unsafe {
            let ptr: *mut gst_sys::GstObject = self.as_ptr() as *mut _;
            let _guard = ::utils::MutexGuard::lock(&(*ptr).lock);
            (*ptr).flags &= !flags.to_glib();
        }
    }

    fn get_bin_flags(&self) -> BinFlags {
        unsafe {
            let ptr: *mut gst_sys::GstObject = self.as_ptr() as *mut _;
            let _guard = ::utils::MutexGuard::lock(&(*ptr).lock);
            from_glib((*ptr).flags)
        }
    }
}

unsafe extern "C" fn trampoline_pad_probe<
    T,
    F: Fn(&T, &mut PadProbeInfo) -> PadProbeReturn + Send + Sync + 'static,
>(
    pad: *mut gst_sys::GstPad,
    info: *mut gst_sys::GstPadProbeInfo,
    func: gpointer,
) -> gst_sys::GstPadProbeReturn
where
    T: IsA<Pad>,
{
    let func: &F = &*(func as *const F);
    let mut data_type = None;

    let mut probe_info = PadProbeInfo {
        mask: from_glib((*info).type_),
        id: PadProbeId((*info).id),
        offset: (*info).offset,
        size: (*info).size,
        data: if (*info).data.is_null() {
            None
        } else {
            let data = (*info).data as *mut gst_sys::GstMiniObject;
            (*info).data = ptr::null_mut();
            if (*data).type_ == Buffer::static_type().to_glib() {
                data_type = Some(Buffer::static_type());
                Some(PadProbeData::Buffer(from_glib_full(
                    data as *const gst_sys::GstBuffer,
                )))
            } else if (*data).type_ == BufferList::static_type().to_glib() {
                data_type = Some(BufferList::static_type());
                Some(PadProbeData::BufferList(from_glib_full(
                    data as *const gst_sys::GstBufferList,
                )))
            } else if (*data).type_ == Query::static_type().to_glib() {
                data_type = Some(Query::static_type());
                Some(PadProbeData::Query(QueryRef::from_mut_ptr(
                    data as *mut gst_sys::GstQuery,
                )))
            } else if (*data).type_ == Event::static_type().to_glib() {
                data_type = Some(Event::static_type());
                Some(PadProbeData::Event(from_glib_full(
                    data as *const gst_sys::GstEvent,
                )))
            } else {
                Some(PadProbeData::__Unknown(data))
            }
        },
        flow_ret: from_glib((*info).ABI.abi.flow_ret),
    };

    let ret = func(&Pad::from_glib_borrow(pad).unsafe_cast(), &mut probe_info);

    if ret == PadProbeReturn::Handled {
        // Handled queries need to be returned
        // Handled buffers are consumed
        // No other types can safely be used here

        match probe_info.data {
            Some(PadProbeData::Query(query)) => {
                assert_eq!(data_type, Some(Query::static_type()));
                (*info).data = query.as_mut_ptr() as *mut libc::c_void;
            }
            Some(PadProbeData::Buffer(_)) => {
                assert_eq!(data_type, Some(Buffer::static_type()));
                // Buffer not consumed by probe; consume it here
            }
            None if data_type == Some(Buffer::static_type()) => {
                // Buffer consumed by probe
            }
            other => panic!(
                "Bad data for {:?} pad probe returning Handled: {:?}",
                data_type, other
            ),
        }
    } else {
        match probe_info.data {
            Some(PadProbeData::Buffer(buffer)) => {
                assert_eq!(data_type, Some(Buffer::static_type()));
                (*info).data = buffer.into_ptr() as *mut libc::c_void;
            }
            Some(PadProbeData::BufferList(bufferlist)) => {
                assert_eq!(data_type, Some(BufferList::static_type()));
                (*info).data = bufferlist.into_ptr() as *mut libc::c_void;
            }
            Some(PadProbeData::Event(event)) => {
                assert_eq!(data_type, Some(Event::static_type()));
                (*info).data = event.into_ptr() as *mut libc::c_void;
            }
            Some(PadProbeData::Query(query)) => {
                assert_eq!(data_type, Some(Query::static_type()));
                (*info).data = query.as_mut_ptr() as *mut libc::c_void;
            }
            Some(PadProbeData::__Unknown(ptr)) => {
                assert_eq!(data_type, None);
                (*info).data = ptr as *mut libc::c_void;
            }
            None => {
                assert_eq!(data_type, None);
            }
        }
    }

    (*info).ABI.abi.flow_ret = probe_info.flow_ret.to_glib();

    ret.to_glib()
}

unsafe extern "C" fn trampoline_activate_function<
    T,
    F: Fn(&T, Option<&::Object>) -> Result<(), LoggableError> + Send + Sync + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
) -> glib_sys::gboolean
where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).activatedata as *const F);

    match func(
        &Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
    ) {
        Ok(()) => true,
        Err(err) => {
            err.log_with_object(&Pad::from_glib_borrow(pad));
            false
        }
    }
    .to_glib()
}

unsafe extern "C" fn trampoline_activatemode_function<
    T,
    F: Fn(&T, Option<&::Object>, ::PadMode, bool) -> Result<(), LoggableError> + Send + Sync + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
    mode: gst_sys::GstPadMode,
    active: glib_sys::gboolean,
) -> glib_sys::gboolean
where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).activatemodedata as *const F);

    match func(
        &&Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
        from_glib(mode),
        from_glib(active),
    ) {
        Ok(()) => true,
        Err(err) => {
            err.log_with_object(&Pad::from_glib_borrow(pad));
            false
        }
    }
    .to_glib()
}

unsafe extern "C" fn trampoline_chain_function<
    T,
    F: Fn(&T, Option<&::Object>, ::Buffer) -> Result<FlowSuccess, FlowError> + Send + Sync + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
    buffer: *mut gst_sys::GstBuffer,
) -> gst_sys::GstFlowReturn
where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).chaindata as *const F);

    let res: FlowReturn = func(
        &Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
        from_glib_full(buffer),
    )
    .into();
    res.to_glib()
}

unsafe extern "C" fn trampoline_chain_list_function<
    T,
    F: Fn(&T, Option<&::Object>, ::BufferList) -> Result<FlowSuccess, FlowError>
        + Send
        + Sync
        + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
    list: *mut gst_sys::GstBufferList,
) -> gst_sys::GstFlowReturn
where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).chainlistdata as *const F);

    let res: FlowReturn = func(
        &Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
        from_glib_full(list),
    )
    .into();
    res.to_glib()
}

unsafe extern "C" fn trampoline_event_function<
    T,
    F: Fn(&T, Option<&::Object>, ::Event) -> bool + Send + Sync + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
    event: *mut gst_sys::GstEvent,
) -> glib_sys::gboolean
where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).eventdata as *const F);

    func(
        &Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
        from_glib_full(event),
    )
    .to_glib()
}

unsafe extern "C" fn trampoline_event_full_function<
    T,
    F: Fn(&T, Option<&::Object>, ::Event) -> Result<FlowSuccess, FlowError> + Send + Sync + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
    event: *mut gst_sys::GstEvent,
) -> gst_sys::GstFlowReturn
where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).eventdata as *const F);

    let res: FlowReturn = func(
        &Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
        from_glib_full(event),
    )
    .into();
    res.to_glib()
}

unsafe extern "C" fn trampoline_getrange_function<
    T,
    F: Fn(&T, Option<&::Object>, u64, u32) -> Result<::Buffer, FlowError> + Send + Sync + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
    offset: u64,
    length: u32,
    buffer: *mut *mut gst_sys::GstBuffer,
) -> gst_sys::GstFlowReturn
where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).getrangedata as *const F);

    match func(
        &Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
        offset,
        length,
    ) {
        Ok(new_buffer) => {
            *buffer = new_buffer.into_ptr();
            FlowReturn::Ok.to_glib()
        }
        Err(ret) => FlowReturn::from_error(ret).to_glib(),
    }
}

unsafe extern "C" fn trampoline_iterate_internal_links_function<
    T,
    F: Fn(&T, Option<&::Object>) -> ::Iterator<Pad> + Send + Sync + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
) -> *mut gst_sys::GstIterator
where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).iterintlinkdata as *const F);

    // Steal the iterator and return it
    let ret = func(
        &Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
    );
    let ptr = ret.to_glib_none().0;
    mem::forget(ret);

    ptr as *mut _
}

unsafe extern "C" fn trampoline_link_function<
    T,
    F: Fn(&T, Option<&::Object>, &::Pad) -> Result<::PadLinkSuccess, ::PadLinkError>
        + Send
        + Sync
        + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
    peer: *mut gst_sys::GstPad,
) -> gst_sys::GstPadLinkReturn
where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).linkdata as *const F);

    let res: ::PadLinkReturn = func(
        &Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
        &from_glib_borrow(peer),
    )
    .into();
    res.to_glib()
}

unsafe extern "C" fn trampoline_query_function<
    T,
    F: Fn(&T, Option<&::Object>, &mut ::QueryRef) -> bool + Send + Sync + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
    query: *mut gst_sys::GstQuery,
) -> glib_sys::gboolean
where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).querydata as *const F);

    func(
        &Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
        ::QueryRef::from_mut_ptr(query),
    )
    .to_glib()
}

unsafe extern "C" fn trampoline_unlink_function<
    T,
    F: Fn(&T, Option<&::Object>) + Send + Sync + 'static,
>(
    pad: *mut gst_sys::GstPad,
    parent: *mut gst_sys::GstObject,
) where
    T: IsA<Pad>,
{
    let func: &F = &*((*pad).unlinkdata as *const F);

    func(
        &Pad::from_glib_borrow(pad).unsafe_cast(),
        Option::<::Object>::from_glib_borrow(parent).as_ref(),
    )
}

unsafe extern "C" fn destroy_closure<F>(ptr: gpointer) {
    Box::<F>::from_raw(ptr as *mut _);
}

unsafe extern "C" fn trampoline_pad_task<F: FnMut() + Send + 'static>(func: gpointer) {
    let func: &RefCell<F> = &*(func as *const RefCell<F>);
    (&mut *func.borrow_mut())()
}

fn into_raw_pad_task<F: FnMut() + Send + 'static>(func: F) -> gpointer {
    #[allow(clippy::type_complexity)]
    let func: Box<RefCell<F>> = Box::new(RefCell::new(func));
    Box::into_raw(func) as gpointer
}

unsafe extern "C" fn destroy_closure_pad_task<F>(ptr: gpointer) {
    Box::<RefCell<F>>::from_raw(ptr as *mut _);
}

#[cfg(test)]
mod tests {
    use super::*;
    use prelude::*;
    use std::sync::mpsc::channel;
    use std::sync::{Arc, Mutex};

    #[test]
    fn test_event_chain_functions() {
        ::init().unwrap();

        let pad = ::Pad::new(Some("sink"), ::PadDirection::Sink);

        let events = Arc::new(Mutex::new(Vec::new()));
        let events_clone = events.clone();
        pad.set_event_function(move |_, _, event| {
            let mut events = events_clone.lock().unwrap();
            events.push(event);

            true
        });

        let buffers = Arc::new(Mutex::new(Vec::new()));
        let buffers_clone = buffers.clone();
        pad.set_chain_function(move |_, _, buffer| {
            let mut buffers = buffers_clone.lock().unwrap();
            buffers.push(buffer);

            Ok(FlowSuccess::Ok)
        });

        pad.set_active(true).unwrap();

        assert!(pad.send_event(::Event::new_stream_start("test").build()));
        let segment = ::FormattedSegment::<::ClockTime>::new();
        assert!(pad.send_event(::Event::new_segment(segment.as_ref()).build()));

        assert_eq!(pad.chain(::Buffer::new()), Ok(FlowSuccess::Ok));

        let events = events.lock().unwrap();
        let buffers = buffers.lock().unwrap();
        assert_eq!(events.len(), 2);
        assert_eq!(buffers.len(), 1);

        match events[0].view() {
            ::EventView::StreamStart(..) => (),
            _ => unreachable!(),
        }

        match events[1].view() {
            ::EventView::Segment(..) => (),
            _ => unreachable!(),
        }
    }

    #[test]
    fn test_task() {
        ::init().unwrap();

        let pad = ::Pad::new(Some("sink"), ::PadDirection::Sink);
        let (sender, receiver) = channel();

        let mut i = 0;
        let pad_clone = pad.clone();
        pad.start_task(move || {
            i += 1;
            if i == 3 {
                sender.send(i).unwrap();
                pad_clone.pause_task().unwrap();
            }
        })
        .unwrap();

        assert_eq!(receiver.recv().unwrap(), 3);
    }

    #[test]
    fn test_probe() {
        ::init().unwrap();

        let (major, minor, micro, _) = ::version();
        let pad = ::Pad::new(Some("src"), ::PadDirection::Src);
        let events = Arc::new(Mutex::new(Vec::new()));
        let buffers = Arc::new(Mutex::new(Vec::new()));

        let flow_override = if (major, minor, micro) >= (1, 16, 1) {
            FlowReturn::Eos
        } else {
            // Broken on 1.16.0
            // https://gitlab.freedesktop.org/gstreamer/gstreamer/merge_requests/151
            FlowReturn::Ok
        };

        {
            let events = events.clone();
            pad.add_probe(::PadProbeType::EVENT_DOWNSTREAM, move |_, info| {
                if let Some(PadProbeData::Event(event)) = &info.data {
                    let mut events = events.lock().unwrap();
                    events.push(event.clone());
                } else {
                    unreachable!();
                }
                ::PadProbeReturn::Ok
            });
        }

        {
            let buffers = buffers.clone();
            let flow_override = flow_override;
            pad.add_probe(::PadProbeType::BUFFER, move |_, info| {
                if let Some(PadProbeData::Buffer(buffer)) = info.data.take() {
                    let mut buffers = buffers.lock().unwrap();
                    info.flow_ret = if buffers.is_empty() {
                        FlowReturn::Ok
                    } else {
                        flow_override
                    };
                    buffers.push(buffer);
                } else {
                    unreachable!();
                }
                ::PadProbeReturn::Handled
            });
        }

        pad.set_active(true).unwrap();

        assert!(pad.push_event(::Event::new_stream_start("test").build()));
        let segment = ::FormattedSegment::<::ClockTime>::new();
        assert!(pad.push_event(::Event::new_segment(segment.as_ref()).build()));

        assert_eq!(pad.push(::Buffer::new()), Ok(FlowSuccess::Ok));
        assert_eq!(pad.push(::Buffer::new()), flow_override.into_result());

        let events = events.lock().unwrap();
        let buffers = buffers.lock().unwrap();
        assert_eq!(events.len(), 2);
        assert_eq!(buffers.len(), 2);

        assert_eq!(events[0].get_type(), ::EventType::StreamStart);
        assert_eq!(events[1].get_type(), ::EventType::Segment);

        assert!(
            buffers.iter().all(|b| b.is_writable()),
            "A buffer ref leaked!"
        );

        drop(pad); // Need to drop the pad first to unref sticky events
        assert!(
            events.iter().all(|e| e.is_writable()),
            "An event ref leaked!"
        );
    }
}