Monitoring global for Pools + API enhancements. (#230)

* Monitoring global for Pools + API enhancements.

* Another layer of API improvements.

* small snafu

* Typo :fp:

Cargo.toml

@@ -124,5 +124,8 @@ tempfile = "3.14.0"
 # rerun
 rerun = "0.21.0"
 
+# smallvec to avoid heap allocations
+smallvec = { version = "1.13.2", features = ["serde"] }
+
 # [profile.release]
 # lto = true

components/sources/cu_v4l/src/lib.rs

@@ -186,8 +186,18 @@ mod linux_impl {
             let mut stream = CuV4LStream::with_buffers(
                 &dev,
                 Type::VideoCapture,
-                actual_fmt.size as usize,
                 req_buffers,
+                CuHostMemoryPool::new(
+                    format!("V4L Host Pool {}", v4l_device).as_str(),
+                    req_buffers as usize + 1,
+                    || vec![0; actual_fmt.size as usize],
+                )
+                .map_err(|e| {
+                    CuError::new_with_cause(
+                        "Could not create host memory pool backing the V4lStream",
+                        e,
+                    )
+                })?,
             )
             .map_err(|e| CuError::new_with_cause("Could not create the V4lStream", e))?;
             debug!("V4L: Set timeout to {} ms", req_timeout.as_millis() as u64);

components/sources/cu_v4l/src/v4lstream.rs

@@ -14,33 +14,55 @@ use v4l::{v4l2, Device};
 pub struct CuV4LStream {
     v4l_handle: Arc<Handle>,
     v4l_buf_type: Type,
-    memory_pool: CuHostMemoryPool<Vec<u8>>,
+    pool: Arc<CuHostMemoryPool<Vec<u8>>>,
     // Arena matching the vl42 metadata and the Copper Buffers
     arena: Vec<(Metadata, Option<CuHandle<Vec<u8>>>)>,
     arena_last_freed_up_index: usize,
     timeout: Option<i32>,
     active: bool,
 }
 
+use std::fs;
+use std::os::fd::RawFd;
+use std::path::PathBuf;
+
+fn get_original_dev_path(fd: RawFd) -> Option<PathBuf> {
+    let link_path = format!("/proc/self/fd/{}", fd);
+
+    if let Ok(path) = fs::read_link(link_path) {
+        if path.to_string_lossy().starts_with("/dev/video") {
+            return Some(path);
+        }
+    }
+    None
+}
+
 impl CuV4LStream {
     #[allow(dead_code)]
     pub fn new(dev: &Device, buf_size: usize, buf_type: Type) -> io::Result<Self> {
-        CuV4LStream::with_buffers(dev, buf_type, buf_size, 4)
+        let original_path = get_original_dev_path(dev.handle().fd()).unwrap();
+        let pool = CuHostMemoryPool::new(
+            format!("V4L Host Pool {}", original_path.display()).as_str(),
+            4,
+            || vec![0; buf_size],
+        )
+        .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
+
+        CuV4LStream::with_buffers(dev, buf_type, 4, pool)
     }
 
     pub fn with_buffers(
         dev: &Device,
         buf_type: Type,
-        buf_size: usize,
         buf_count: u32,
+        pool: Arc<CuHostMemoryPool<Vec<u8>>>,
     ) -> io::Result<Self> {
-        let memory_pool = CuHostMemoryPool::new(buf_count as usize + 1, || vec![0; buf_size]); // +1 to be able to queue one last buffer before zapping the first
         let mut arena = Vec::new();
         arena.resize(buf_count as usize, (Metadata::default(), None));
 
         let mut result = CuV4LStream {
             v4l_handle: dev.handle(),
-            memory_pool,
+            pool,
             arena,
             arena_last_freed_up_index: 0,
             v4l_buf_type: buf_type,
@@ -191,7 +213,7 @@ impl Stream for CuV4LStream {
 
 impl CaptureStream<'_> for CuV4LStream {
     fn queue(&mut self, index: usize) -> io::Result<()> {
-        let buffer_handle = self.memory_pool.acquire().unwrap();
+        let buffer_handle = self.pool.acquire().unwrap();
         self.arena[index] = (Metadata::default(), Some(buffer_handle.clone()));
         let mut v4l2_buf = buffer_handle.with_inner_mut(|inner| {
             let destination: &mut [u8] = inner;

core/cu29_log_runtime/Cargo.toml

@@ -19,7 +19,7 @@ cu29-log = { workspace = true }
 cu29-traits = { workspace = true }
 cu29-clock = { workspace = true }
 bincode = { workspace = true }
-smallvec = "1.13.2"
+smallvec = { workspace = true }
 log = "0.4.22"
 
 [dev-dependencies]

core/cu29_runtime/Cargo.toml

@@ -34,6 +34,7 @@ cu29-clock = { workspace = true }
 clap = { workspace = true }
 tempfile = { workspace = true }
 arrayvec = "0.7.6"
+smallvec = { workspace = true }
 ron = "0.8.1"
 hdrhistogram = "7.5.4"
 petgraph = { version = "0.7.1", features = ["serde", "serde-1", "serde_derive"] }