diff --git a/libs/utils/src/http/endpoint.rs b/libs/utils/src/http/endpoint.rs index 4b4aa88d6b..a6ba685447 100644 --- a/libs/utils/src/http/endpoint.rs +++ b/libs/utils/src/http/endpoint.rs @@ -15,7 +15,7 @@ use once_cell::sync::Lazy; use regex::Regex; use routerify::ext::RequestExt; use routerify::{Middleware, RequestInfo, Router, RouterBuilder}; -use tokio::sync::{mpsc, Mutex}; +use tokio::sync::{mpsc, Mutex, Notify}; use tokio_stream::wrappers::ReceiverStream; use tokio_util::io::ReaderStream; use tracing::{debug, info, info_span, warn, Instrument}; @@ -358,25 +358,41 @@ pub async fn profile_cpu_handler(req: Request) -> Result, A Some(1001..) => return Err(ApiError::BadRequest(anyhow!("frequency must be <=1000 Hz"))), Some(frequency) => frequency, }; - - // Only allow one profiler at a time. - static PROFILE_LOCK: Lazy> = Lazy::new(|| Mutex::new(())); - let _lock = PROFILE_LOCK - .try_lock() - .map_err(|_| ApiError::Conflict("profiler already running".into()))?; + let force: bool = parse_query_param(&req, "force")?.unwrap_or_default(); // Take the profile. - let report = tokio::task::spawn_blocking(move || { + static PROFILE_LOCK: Lazy> = Lazy::new(|| Mutex::new(())); + static PROFILE_CANCEL: Lazy = Lazy::new(Notify::new); + + let report = { + // Only allow one profiler at a time. If force is true, cancel a running profile (e.g. a + // Grafana continuous profile). We use a try_lock() loop when cancelling instead of waiting + // for a lock(), to avoid races where the notify isn't currently awaited. + let _lock = loop { + match PROFILE_LOCK.try_lock() { + Ok(lock) => break lock, + Err(_) if force => PROFILE_CANCEL.notify_waiters(), + Err(_) => return Err(ApiError::Conflict("profiler already running".into())), + } + tokio::time::sleep(Duration::from_millis(1)).await; // don't busy-wait + }; + let guard = ProfilerGuardBuilder::default() .frequency(frequency_hz) .blocklist(&["libc", "libgcc", "pthread", "vdso"]) - .build()?; - std::thread::sleep(Duration::from_secs(seconds)); - guard.report().build() - }) - .await - .map_err(|join_err| ApiError::InternalServerError(join_err.into()))? - .map_err(|pprof_err| ApiError::InternalServerError(pprof_err.into()))?; + .build() + .map_err(|err| ApiError::InternalServerError(err.into()))?; + + tokio::select! { + _ = tokio::time::sleep(Duration::from_secs(seconds)) => {}, + _ = PROFILE_CANCEL.notified() => {}, + }; + + guard + .report() + .build() + .map_err(|err| ApiError::InternalServerError(err.into()))? + }; // Return the report in the requested format. match format {