First attempt at async host side

level_zero/src/ze.rs

@@ -325,6 +325,11 @@ impl<'a> CommandQueue<'a> {
         ));
         Ok(())
     }
+
+    pub fn synchronize(&self, timeout_ns: u64) -> Result<()> {
+        check!(sys::zeCommandQueueSynchronize(self.as_ffi(), timeout_ns));
+        Ok(())
+    }
 }
 
 impl<'a> Drop for CommandQueue<'a> {
@@ -1097,6 +1102,15 @@ impl<'a> Event<'a> {
         Ok(unsafe { Self::from_ffi(result) })
     }
 
+    pub fn is_ready(&self) -> Result<bool> {
+        let status = unsafe { sys::zeEventQueryStatus(self.as_ffi()) };
+        match status {
+            sys::ze_result_t::ZE_RESULT_SUCCESS => Ok(true),
+            sys::ze_result_t::ZE_RESULT_NOT_READY => Ok(false),
+            err => Err(err),
+        }
+    }
+
     unsafe fn with_raw_slice<'x, T>(
         events: &[&Event<'x>],
         f: impl FnOnce(u32, *mut sys::ze_event_handle_t) -> T,

zluda/src/cuda.rs

@@ -2186,7 +2186,7 @@ pub extern "system" fn cuGetErrorString(
     error: CUresult,
     pStr: *mut *const ::std::os::raw::c_char,
 ) -> CUresult {
-    r#impl::get_error_string(error,  pStr).encuda()
+    r#impl::get_error_string(error, pStr).encuda()
 }
 
 #[cfg_attr(not(test), no_mangle)]
@@ -2209,7 +2209,10 @@ pub extern "system" fn cuDriverGetVersion(driverVersion: *mut ::std::os::raw::c_
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuDeviceGet(device: *mut CUdevice, ordinal: ::std::os::raw::c_int) -> CUresult {
+pub extern "system" fn cuDeviceGet(
+    device: *mut CUdevice,
+    ordinal: ::std::os::raw::c_int,
+) -> CUresult {
     r#impl::device::get(device.decuda(), ordinal).encuda()
 }
 
@@ -2374,7 +2377,7 @@ pub extern "system" fn cuCtxGetFlags(flags: *mut ::std::os::raw::c_uint) -> CUre
 
 #[cfg_attr(not(test), no_mangle)]
 pub extern "system" fn cuCtxSynchronize() -> CUresult {
-    r#impl::context::synchronize()
+    r#impl::context::synchronize().encuda()
 }
 
 #[cfg_attr(not(test), no_mangle)]
@@ -2429,7 +2432,10 @@ pub extern "system" fn cuCtxResetPersistingL2Cache() -> CUresult {
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuCtxAttach(pctx: *mut CUcontext, flags: ::std::os::raw::c_uint) -> CUresult {
+pub extern "system" fn cuCtxAttach(
+    pctx: *mut CUcontext,
+    flags: ::std::os::raw::c_uint,
+) -> CUresult {
     r#impl::context::attach(pctx.decuda(), flags).encuda()
 }
 
@@ -2667,7 +2673,10 @@ pub extern "system" fn cuDeviceGetPCIBusId(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuIpcGetEventHandle(pHandle: *mut CUipcEventHandle, event: CUevent) -> CUresult {
+pub extern "system" fn cuIpcGetEventHandle(
+    pHandle: *mut CUipcEventHandle,
+    event: CUevent,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -2680,7 +2689,10 @@ pub extern "system" fn cuIpcOpenEventHandle(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuIpcGetMemHandle(pHandle: *mut CUipcMemHandle, dptr: CUdeviceptr) -> CUresult {
+pub extern "system" fn cuIpcGetMemHandle(
+    pHandle: *mut CUipcMemHandle,
+    dptr: CUdeviceptr,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -2930,12 +2942,18 @@ pub extern "system" fn cuMemcpyAtoHAsync_v2(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuMemcpy2DAsync_v2(pCopy: *const CUDA_MEMCPY2D, hStream: CUstream) -> CUresult {
+pub extern "system" fn cuMemcpy2DAsync_v2(
+    pCopy: *const CUDA_MEMCPY2D,
+    hStream: CUstream,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuMemcpy3DAsync_v2(pCopy: *const CUDA_MEMCPY3D, hStream: CUstream) -> CUresult {
+pub extern "system" fn cuMemcpy3DAsync_v2(
+    pCopy: *const CUDA_MEMCPY3D,
+    hStream: CUstream,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -3406,7 +3424,9 @@ pub extern "system" fn cuStreamBeginCapture_v2(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuThreadExchangeStreamCaptureMode(mode: *mut CUstreamCaptureMode) -> CUresult {
+pub extern "system" fn cuThreadExchangeStreamCaptureMode(
+    mode: *mut CUstreamCaptureMode,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -3449,7 +3469,7 @@ pub extern "system" fn cuStreamQuery(hStream: CUstream) -> CUresult {
 
 #[cfg_attr(not(test), no_mangle)]
 pub extern "system" fn cuStreamSynchronize(hStream: CUstream) -> CUresult {
-    CUresult::CUDA_SUCCESS
+    r#impl::stream::synchronize(hStream.decuda()).encuda()
 }
 
 #[cfg_attr(not(test), no_mangle)]
@@ -3481,7 +3501,10 @@ pub extern "system" fn cuStreamSetAttribute(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuEventCreate(phEvent: *mut CUevent, Flags: ::std::os::raw::c_uint) -> CUresult {
+pub extern "system" fn cuEventCreate(
+    phEvent: *mut CUevent,
+    Flags: ::std::os::raw::c_uint,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -3652,7 +3675,10 @@ pub extern "system" fn cuFuncSetCacheConfig(hfunc: CUfunction, config: CUfunc_ca
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuFuncSetSharedMemConfig(hfunc: CUfunction, config: CUsharedconfig) -> CUresult {
+pub extern "system" fn cuFuncSetSharedMemConfig(
+    hfunc: CUfunction,
+    config: CUsharedconfig,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -3770,7 +3796,10 @@ pub extern "system" fn cuFuncSetSharedSize(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuParamSetSize(hfunc: CUfunction, numbytes: ::std::os::raw::c_uint) -> CUresult {
+pub extern "system" fn cuParamSetSize(
+    hfunc: CUfunction,
+    numbytes: ::std::os::raw::c_uint,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -3836,7 +3865,10 @@ pub extern "system" fn cuParamSetTexRef(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuGraphCreate(phGraph: *mut CUgraph, flags: ::std::os::raw::c_uint) -> CUresult {
+pub extern "system" fn cuGraphCreate(
+    phGraph: *mut CUgraph,
+    flags: ::std::os::raw::c_uint,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -3980,7 +4012,10 @@ pub extern "system" fn cuGraphAddEmptyNode(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuGraphClone(phGraphClone: *mut CUgraph, originalGraph: CUgraph) -> CUresult {
+pub extern "system" fn cuGraphClone(
+    phGraphClone: *mut CUgraph,
+    originalGraph: CUgraph,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -3994,7 +4029,10 @@ pub extern "system" fn cuGraphNodeFindInClone(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuGraphNodeGetType(hNode: CUgraphNode, type_: *mut CUgraphNodeType) -> CUresult {
+pub extern "system" fn cuGraphNodeGetType(
+    hNode: CUgraphNode,
+    type_: *mut CUgraphNodeType,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -4144,7 +4182,10 @@ pub extern "system" fn cuGraphExecUpdate(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuGraphKernelNodeCopyAttributes(dst: CUgraphNode, src: CUgraphNode) -> CUresult {
+pub extern "system" fn cuGraphKernelNodeCopyAttributes(
+    dst: CUgraphNode,
+    src: CUgraphNode,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -4284,7 +4325,10 @@ pub extern "system" fn cuTexRefSetFilterMode(hTexRef: CUtexref, fm: CUfilter_mod
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuTexRefSetMipmapFilterMode(hTexRef: CUtexref, fm: CUfilter_mode) -> CUresult {
+pub extern "system" fn cuTexRefSetMipmapFilterMode(
+    hTexRef: CUtexref,
+    fm: CUfilter_mode,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -4311,17 +4355,26 @@ pub extern "system" fn cuTexRefSetMaxAnisotropy(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuTexRefSetBorderColor(hTexRef: CUtexref, pBorderColor: *mut f32) -> CUresult {
+pub extern "system" fn cuTexRefSetBorderColor(
+    hTexRef: CUtexref,
+    pBorderColor: *mut f32,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuTexRefSetFlags(hTexRef: CUtexref, Flags: ::std::os::raw::c_uint) -> CUresult {
+pub extern "system" fn cuTexRefSetFlags(
+    hTexRef: CUtexref,
+    Flags: ::std::os::raw::c_uint,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuTexRefGetAddress_v2(pdptr: *mut CUdeviceptr, hTexRef: CUtexref) -> CUresult {
+pub extern "system" fn cuTexRefGetAddress_v2(
+    pdptr: *mut CUdeviceptr,
+    hTexRef: CUtexref,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -4348,7 +4401,10 @@ pub extern "system" fn cuTexRefGetAddressMode(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuTexRefGetFilterMode(pfm: *mut CUfilter_mode, hTexRef: CUtexref) -> CUresult {
+pub extern "system" fn cuTexRefGetFilterMode(
+    pfm: *mut CUfilter_mode,
+    hTexRef: CUtexref,
+) -> CUresult {
     r#impl::unimplemented()
 }
 
@@ -4392,7 +4448,10 @@ pub extern "system" fn cuTexRefGetMaxAnisotropy(
 }
 
 #[cfg_attr(not(test), no_mangle)]
-pub extern "system" fn cuTexRefGetBorderColor(pBorderColor: *mut f32, hTexRef: CUtexref) -> CUresult {
+pub extern "system" fn cuTexRefGetBorderColor(
+    pBorderColor: *mut f32,
+    hTexRef: CUtexref,
+) -> CUresult {
     r#impl::unimplemented()
 }
 

zluda/src/impl/context.rs

@@ -257,9 +257,14 @@ pub fn detach(pctx: *mut Context) -> Result<(), CUresult> {
     })?
 }
 
-pub(crate) fn synchronize() -> CUresult {
+pub(crate) fn synchronize() -> Result<(), CUresult> {
-    // TODO: change the implementation once we do async stream operations
+    GlobalState::lock_current_context(|ctx| {
-    CUresult::CUDA_SUCCESS
+        ctx.default_stream.synchronize()?;
+        for stream in ctx.streams.iter().copied() {
+            unsafe { &mut *stream }.synchronize()?;
+        }
+        Ok(())
+    })?
 }
 
 #[cfg(test)]

zluda/src/impl/device.rs

@@ -1,4 +1,4 @@
-use super::{context, CUresult, GlobalState};
+use super::{context, transmute_lifetime, transmute_lifetime_mut, CUresult, GlobalState};
 use crate::cuda;
 use cuda::{CUdevice_attribute, CUuuid_st};
 use std::{
@@ -21,6 +21,7 @@ pub struct Device {
     pub default_queue: l0::CommandQueue<'static>,
     pub l0_context: l0::Context,
     pub primary_context: context::Context,
+    pub event_pool: DynamicEventPool,
     properties: Option<Box<l0::sys::ze_device_properties_t>>,
     image_properties: Option<Box<l0::sys::ze_device_image_properties_t>>,
     memory_properties: Option<Vec<l0::sys::ze_device_memory_properties_t>>,
@@ -42,12 +43,14 @@ impl Device {
             true,
             ptr::null_mut(),
         )?);
+        let event_pool = DynamicEventPool::new(l0_dev, transmute_lifetime(&ctx))?;
         Ok(Self {
             index: Index(idx as c_int),
             base: l0_dev,
             default_queue: queue,
             l0_context: ctx,
             primary_context: primary_context,
+            event_pool,
             properties: None,
             image_properties: None,
             memory_properties: None,
@@ -395,8 +398,103 @@ pub(crate) fn primary_ctx_release_v2(_dev_idx: Index) -> CUresult {
     CUresult::CUDA_SUCCESS
 }
 
+pub struct DynamicEventPool {
+    count: usize,
+    events: Vec<DynamicEventPoolEntry>,
+}
+
+impl DynamicEventPool {
+    fn new(dev: l0::Device, ctx: &'static l0::Context) -> l0::Result<Self> {
+        Ok(DynamicEventPool {
+            count: 0,
+            events: vec![DynamicEventPoolEntry::new(dev, ctx)?],
+        })
+    }
+
+    pub fn get(
+        &'static mut self,
+        dev: l0::Device,
+        ctx: &'static l0::Context,
+    ) -> l0::Result<(l0::Event<'static>, u64)> {
+        self.count += 1;
+        let events = unsafe { transmute_lifetime_mut(&mut self.events) };
+        let (global_idx, (ev, local_idx)) = {
+            for (idx, entry) in self.events.iter_mut().enumerate() {
+                if let Some((ev, local_idx)) = entry.get()? {
+                    let marker = (idx << 32) as u64 | local_idx as u64;
+                    return Ok((ev, marker));
+                }
+            }
+            events.push(DynamicEventPoolEntry::new(dev, ctx)?);
+            let global_idx = (events.len() - 1) as u64;
+            (global_idx, events.last_mut().unwrap().get()?.unwrap())
+        };
+        let marker = (global_idx << 32) | local_idx as u64;
+        Ok((ev, marker))
+    }
+
+    pub fn mark_as_free(&mut self, marker: u64) {
+        let global_idx = (marker >> 32) as u32;
+        self.events[global_idx as usize].mark_as_free(marker as u32);
+        self.count -= 1;
+        // TODO: clean up empty entries
+    }
+}
+
+const DYNAMIC_EVENT_POOL_ENTRY_SIZE: usize = 448;
+const DYNAMIC_EVENT_POOL_ENTRY_BITMAP_SIZE: usize =
+    DYNAMIC_EVENT_POOL_ENTRY_SIZE / (mem::size_of::<u64>() * 8);
+#[repr(C)]
+#[repr(align(64))]
+struct DynamicEventPoolEntry {
+    event_pool: l0::EventPool<'static>,
+    bit_map: [u64; DYNAMIC_EVENT_POOL_ENTRY_BITMAP_SIZE],
+}
+
+impl DynamicEventPoolEntry {
+    fn new(dev: l0::Device, ctx: &'static l0::Context) -> l0::Result<Self> {
+        Ok(DynamicEventPoolEntry {
+            event_pool: l0::EventPool::new(
+                ctx,
+                DYNAMIC_EVENT_POOL_ENTRY_SIZE as u32,
+                Some(&[dev]),
+            )?,
+            bit_map: [0; DYNAMIC_EVENT_POOL_ENTRY_BITMAP_SIZE],
+        })
+    }
+
+    fn get(&'static mut self) -> l0::Result<Option<(l0::Event<'static>, u32)>> {
+        for (idx, value) in self.bit_map.iter_mut().enumerate() {
+            let shift = first_index_of_zero_u64(*value);
+            if shift == 64 {
+                continue;
+            }
+            *value = *value | (1u64 << shift);
+            let entry_index = (idx as u32 * 64u32) + shift;
+            let event = l0::Event::new(&self.event_pool, entry_index)?;
+            return Ok(Some((event, entry_index)));
+        }
+        Ok(None)
+    }
+
+    fn mark_as_free(&mut self, idx: u32) {
+        let value = &mut self.bit_map[idx as usize / 64];
+        let shift = idx % 64;
+        *value = *value & !(1 << shift);
+    }
+}
+
+fn first_index_of_zero_u64(x: u64) -> u32 {
+    let x = !x;
+    (x & x.wrapping_neg()).trailing_zeros()
+}
+
 #[cfg(test)]
 mod test {
+    use std::mem;
+
+    use super::DynamicEventPoolEntry;
+
     use super::super::test::CudaDriverFns;
     use super::super::CUresult;
 
@@ -413,4 +511,10 @@ mod test {
         assert_eq!(flags, 0);
         assert_eq!(active, 0);
     }
+
+    #[test]
+    pub fn dynamic_event_pool_page_is_64b() {
+        assert_eq!(mem::size_of::<DynamicEventPoolEntry>(), 64);
+        assert_eq!(mem::align_of::<DynamicEventPoolEntry>(), 64);
+    }
 }

zluda/src/impl/memory.rs

@@ -11,13 +11,10 @@ pub fn alloc_v2(dptr: *mut *mut c_void, bytesize: usize) -> Result<(), CUresult>
 }
 
 pub fn copy_v2(dst: *mut c_void, src: *const c_void, bytesize: usize) -> Result<(), CUresult> {
-    GlobalState::lock_stream(stream::CU_STREAM_LEGACY, |stream| {
+    GlobalState::lock_enqueue(stream::CU_STREAM_LEGACY, |cmd_list, signal, wait| {
-        let cmd_list = stream.command_list()?;
+        unsafe { cmd_list.append_memory_copy_raw(dst, src, bytesize, Some(signal), wait)? };
-        unsafe { cmd_list.append_memory_copy_raw(dst, src, bytesize, None, &mut [])? };
+        Ok::<_, l0::sys::ze_result_t>(())
-        cmd_list.close()?;
+    })
-        stream.queue.execute_and_synchronize(cmd_list)?;
-        Ok::<_, CUresult>(())
-    })?
 }
 
 pub fn free_v2(ptr: *mut c_void) -> Result<(), CUresult> {

zluda/src/impl/mod.rs

@@ -273,6 +273,32 @@ impl GlobalState {
         }
     }
 
+    fn lock_enqueue(
+        stream: *mut stream::Stream,
+        f: impl FnOnce(
+            &mut l0::CommandList,
+            &l0::Event<'static>,
+            &[&l0::Event<'static>],
+        ) -> l0::Result<()>,
+    ) -> Result<(), CUresult> {
+        Self::lock_stream(stream, |stream_data| {
+            let l0_dev = unsafe { (*(*stream_data.context).device).base };
+            let l0_ctx = unsafe { &mut (*(*stream_data.context).device).l0_context };
+            let event_pool = unsafe { &mut (*(*stream_data.context).device).event_pool };
+            let mut cmd_list = unsafe { mem::transmute(stream_data.command_list()?) };
+            stream_data
+                .process_finished_events(&mut |(_, marker)| event_pool.mark_as_free(marker))?;
+            let prev_event = stream_data.get_last_event();
+            let prev_event_array = prev_event.map(|e| [e]);
+            let empty = [];
+            let prev_event_slice = prev_event_array.as_ref().map_or(&empty[..], |arr| &arr[..]);
+            let (new_event, new_marker) = event_pool.get(l0_dev, l0_ctx)?;
+            f(&mut cmd_list, &new_event, prev_event_slice)?;
+            stream_data.push_event((new_event, new_marker));
+            Ok(())
+        })?
+    }
+
     fn lock_function<T>(
         func: *mut function::Function,
         f: impl FnOnce(&mut function::FunctionData) -> T,
@@ -421,6 +447,10 @@ pub(crate) fn get_error_string(error: CUresult, str: *mut *const i8) -> CUresult
     }
 }
 
+unsafe fn transmute_lifetime<'a, 'b, T: ?Sized>(t: &'a T) -> &'b T {
+    mem::transmute(t)
+}
+
 unsafe fn transmute_lifetime_mut<'a, 'b, T: ?Sized>(t: &'a mut T) -> &'b mut T {
     mem::transmute(t)
 }

zluda/src/impl/stream.rs

@@ -2,7 +2,7 @@ use super::{
     context::{Context, ContextData},
     CUresult, GlobalState,
 };
-use std::{mem, ptr};
+use std::{collections::VecDeque, mem, ptr};
 
 use super::{HasLivenessCookie, LiveCheck};
 
@@ -34,21 +34,27 @@ impl HasLivenessCookie for StreamData {
 pub struct StreamData {
     pub context: *mut ContextData,
     pub queue: l0::CommandQueue<'static>,
+    pub prev_events: VecDeque<(l0::Event<'static>, u64)>,
 }
 
 impl StreamData {
-    pub fn new_unitialized(ctx: &'static l0::Context, dev: l0::Device) -> Result<Self, CUresult> {
+    pub fn new_unitialized(
+        ctx: &'static l0::Context,
+        device: l0::Device,
+    ) -> Result<Self, CUresult> {
         Ok(StreamData {
             context: ptr::null_mut(),
-            queue: l0::CommandQueue::new(ctx, dev)?,
+            queue: l0::CommandQueue::new(ctx, device)?,
+            prev_events: VecDeque::new(),
         })
     }
     pub fn new(ctx: &mut ContextData) -> Result<Self, CUresult> {
         let l0_ctx = &mut unsafe { &mut *ctx.device }.l0_context;
-        let l0_dev = unsafe { &*ctx.device }.base;
+        let device = unsafe { &*ctx.device }.base;
         Ok(StreamData {
             context: ctx as *mut _,
-            queue: l0::CommandQueue::new(l0_ctx, l0_dev)?,
+            queue: l0::CommandQueue::new(l0_ctx, device)?,
+            prev_events: VecDeque::new(),
         })
     }
 
@@ -57,6 +63,39 @@ impl StreamData {
         let dev = unsafe { &mut *ctx.device };
         l0::CommandList::new(&mut dev.l0_context, dev.base)
     }
+
+    pub fn process_finished_events(
+        &mut self,
+        f: &mut impl FnMut((l0::Event<'static>, u64)),
+    ) -> l0::Result<()> {
+        loop {
+            match self.prev_events.get(0) {
+                None => return Ok(()),
+                Some((ev, _)) => {
+                    if ev.is_ready()? {
+                        f(self.prev_events.pop_front().unwrap());
+                    } else {
+                        return Ok(());
+                    }
+                }
+            }
+        }
+    }
+
+    pub fn get_last_event(&self) -> Option<&l0::Event<'static>> {
+        self.prev_events.iter().next_back().map(|(ev, _)| ev)
+    }
+
+    pub fn push_event(&mut self, ev: (l0::Event<'static>, u64)) {
+        self.prev_events.push_back(ev);
+    }
+
+    pub fn synchronize(&mut self) -> l0::Result<()> {
+        self.queue.synchronize(u64::MAX)?;
+        let event_pool = unsafe { &mut (*(*self.context).device).event_pool };
+        self.process_finished_events(&mut |(_, marker)| event_pool.mark_as_free(marker))?;
+        Ok(())
+    }
 }
 
 impl Drop for StreamData {
@@ -102,6 +141,13 @@ pub(crate) fn destroy_v2(pstream: *mut Stream) -> Result<(), CUresult> {
     GlobalState::lock(|_| Stream::destroy_impl(pstream))?
 }
 
+pub(crate) fn synchronize(pstream: *mut Stream) -> Result<(), CUresult> {
+    if pstream == ptr::null_mut() {
+        return Err(CUresult::CUDA_ERROR_INVALID_VALUE);
+    }
+    GlobalState::lock_stream(pstream, |stream_data| Ok(stream_data.synchronize()?))?
+}
+
 #[cfg(test)]
 mod test {
     use crate::cuda::CUstream;