From 646b31d2bd42dd8dd591e14d0b6a711511dab699 Mon Sep 17 00:00:00 2001
From: Benjamin Lee <benjamin@computer.surgery>
Date: Fri, 26 Apr 2024 18:37:50 -0700
Subject: [PATCH] flush tracing-flame output file on exit
Previously we were dropping the flush guard early, possibly causing
samples to be lost on exit.
---
src/main.rs | 40 +++++++++++++++++++++++++---------------
1 file changed, 25 insertions(+), 15 deletions(-)
diff --git a/src/main.rs b/src/main.rs
index ef93a5a8..128766ea 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -7,7 +7,7 @@ use std::os::unix::fs::PermissionsExt as _; /* not unix specific, just only for
// are not stable as of writing This is the case for every other occurence of
// sync Mutex/RwLock, except for database related ones
use std::sync::{Arc, RwLock};
-use std::{any::Any, io, net::SocketAddr, sync::atomic, time::Duration};
+use std::{any::Any, fs, io, net::SocketAddr, sync::atomic, time::Duration};
use api::ruma_wrapper::{Ruma, RumaResponse};
use axum::{
@@ -83,6 +83,8 @@ struct Server {
#[cfg(feature = "sentry_telemetry")]
_sentry_guard: Option<sentry::ClientInitGuard>,
+
+ _tracing_flame_guard: TracingFlameGuard,
}
fn main() -> Result<(), Error> {
@@ -476,7 +478,7 @@ fn init(args: clap::Args) -> Result<Server, Error> {
None
};
- let tracing_reload_handle = init_tracing(&config);
+ let (tracing_reload_handle, tracing_flame_guard) = init_tracing(&config);
config.check()?;
@@ -506,6 +508,7 @@ fn init(args: clap::Args) -> Result<Server, Error> {
#[cfg(feature = "sentry_telemetry")]
_sentry_guard: sentry_guard,
+ _tracing_flame_guard: tracing_flame_guard,
})
}
@@ -579,10 +582,15 @@ impl LogLevelReloadHandles {
}
}
+#[cfg(feature = "perf_measurements")]
+type TracingFlameGuard = Option<tracing_flame::FlushGuard<io::BufWriter<fs::File>>>;
+#[cfg(not(feature = "perf_measurements"))]
+type TracingFlameGuard = ();
+
// clippy thinks the filter_layer clones are redundant if the next usage is
// behind a disabled feature.
#[allow(clippy::redundant_clone)]
-fn init_tracing(config: &Config) -> LogLevelReloadHandles {
+fn init_tracing(config: &Config) -> (LogLevelReloadHandles, TracingFlameGuard) {
let registry = Registry::default();
let fmt_layer = tracing_subscriber::fmt::Layer::new();
let filter_layer = match EnvFilter::try_new(&config.log) {
@@ -615,22 +623,20 @@ fn init_tracing(config: &Config) -> LogLevelReloadHandles {
};
#[cfg(feature = "perf_measurements")]
- let subscriber = {
- let flame_layer = if config.tracing_flame {
+ let (subscriber, flame_guard) = {
+ let (flame_layer, flame_guard) = if config.tracing_flame {
let flame_filter = match EnvFilter::try_new(&config.tracing_flame_filter) {
Ok(flame_filter) => flame_filter,
Err(e) => panic!("tracing_flame_filter config value is invalid: {e}"),
};
- // TODO: actually preserve this guard until exit: https://docs.rs/tracing-flame/latest/tracing_flame/struct.FlameLayer.html#dropping-and-flushing
- let (flame_layer, _guard) = tracing_flame::FlameLayer::with_file("./tracing.folded").unwrap();
- Some(
- flame_layer
- .with_empty_samples(false)
- .with_filter(flame_filter),
- )
+ let (flame_layer, flame_guard) = tracing_flame::FlameLayer::with_file("./tracing.folded").unwrap();
+ let flame_layer = flame_layer
+ .with_empty_samples(false)
+ .with_filter(flame_filter);
+ (Some(flame_layer), Some(flame_guard))
} else {
- None
+ (None, None)
};
let jaeger_layer = if config.allow_jaeger {
@@ -649,9 +655,13 @@ fn init_tracing(config: &Config) -> LogLevelReloadHandles {
None
};
- subscriber.with(flame_layer).with(jaeger_layer)
+ let subscriber = subscriber.with(flame_layer).with(jaeger_layer);
+ (subscriber, flame_guard)
};
+ #[cfg(not(feature = "perf_measurements"))]
+ let flame_guard = ();
+
tracing::subscriber::set_global_default(subscriber).unwrap();
#[cfg(all(feature = "tokio_console", feature = "release_max_log_level"))]
@@ -660,7 +670,7 @@ fn init_tracing(config: &Config) -> LogLevelReloadHandles {
needs access to trace-level events. 'release_max_log_level' must be disabled to use tokio-console."
);
- LogLevelReloadHandles::new(reload_handles)
+ (LogLevelReloadHandles::new(reload_handles), flame_guard)
}
// This is needed for opening lots of file descriptors, which tends to