From 566243ade559105be3ff553e8a772c9a0c81bfb9 Mon Sep 17 00:00:00 2001
From: Wez Furlong <wez@wezfurlong.org>
Date: Sat, 10 Jul 2021 20:53:10 -0700
Subject: [PATCH] mux: add some metrics around reading from ptys

---
 Cargo.lock     |  1 +
 mux/Cargo.toml |  1 +
 mux/src/lib.rs | 15 +++++++++++++--
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 9de12f317..73f5934c0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2499,6 +2499,7 @@ dependencies = [
  "libc",
  "log",
  "luahelper",
+ "metrics",
  "portable-pty",
  "promise",
  "rangeset",
diff --git a/mux/Cargo.toml b/mux/Cargo.toml
index cad5567ff..b001297ac 100644
--- a/mux/Cargo.toml
+++ b/mux/Cargo.toml
@@ -19,6 +19,7 @@ lazy_static = "1.4"
 libc = "0.2"
 log = "0.4"
 luahelper = { path = "../luahelper" }
+metrics = { version="0.16", features=["std"]}
 portable-pty = { path = "../pty", features = ["serde_support"]}
 promise = { path = "../promise" }
 rangeset = { path = "../rangeset" }
diff --git a/mux/src/lib.rs b/mux/src/lib.rs
index e3a7067e3..d103596c5 100644
--- a/mux/src/lib.rs
+++ b/mux/src/lib.rs
@@ -5,6 +5,7 @@ use anyhow::{anyhow, Error};
 use config::{configuration, ExitBehavior};
 use domain::{Domain, DomainId};
 use log::error;
+use metrics::histogram;
 use portable_pty::ExitStatus;
 use std::cell::{Ref, RefCell, RefMut};
 use std::collections::HashMap;
@@ -13,9 +14,8 @@ use std::io::Read;
 use std::rc::Rc;
 use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
 use std::sync::{Arc, Condvar, Mutex};
-use std::time::Duration;
-
 use std::thread;
+use std::time::{Duration, Instant};
 use termwiz::escape::Action;
 use thiserror::*;
 
@@ -66,12 +66,18 @@ pub struct Mux {
 /// It blocks until the mux has finished consuming the data, which provides
 /// some back-pressure so that eg: ctrl-c can remain responsive.
 fn send_actions_to_mux(pane_id: PaneId, dead: &Arc<AtomicBool>, actions: Vec<Action>) {
+    let start = Instant::now();
     promise::spawn::block_on(promise::spawn::spawn_into_main_thread({
         let dead = Arc::clone(&dead);
         async move {
             let mux = Mux::get().unwrap();
             if let Some(pane) = mux.get_pane(pane_id) {
+                let start = Instant::now();
                 pane.perform_actions(actions);
+                histogram!(
+                    "send_actions_to_mux.perform_actions.latency",
+                    start.elapsed()
+                );
                 mux.notify(MuxNotification::PaneOutput(pane_id));
             } else {
                 // Something else removed the pane from
@@ -81,6 +87,8 @@ fn send_actions_to_mux(pane_id: PaneId, dead: &Arc<AtomicBool>, actions: Vec<Act
             }
         }
     }));
+    histogram!("send_actions_to_mux.latency", start.elapsed());
+    histogram!("send_actions_to_mux.rate", 1.);
 }
 
 struct BufState {
@@ -91,8 +99,10 @@ struct BufState {
 
 impl BufState {
     fn write(&self, buf: &[u8]) {
+        let start = Instant::now();
         let mut queue = self.queue.lock().unwrap();
         queue.extend(buf);
+        histogram!("read_from_pane_pty.BufState.extend", start.elapsed());
         self.cond.notify_one();
     }
 }
@@ -179,6 +189,7 @@ fn read_from_pane_pty(pane_id: PaneId, banner: Option<String>, mut reader: Box<d
                 break;
             }
             Ok(size) => {
+                histogram!("read_from_pane_pty.bytes.rate", size as f64);
                 state.write(&buf[..size]);
             }
         }