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Switch the desktop encoder on SIGUSR2 without dropping the session #96
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
|
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@@ -144,10 +144,46 @@ fn set_video_pref() -> Result<(), Box<dyn std::error::Error>> { | |
| let selection = video_select::selection(); | ||
| let codec = match selection.codec_pref { video_select::CodecPref::Auto => "auto", video_select::CodecPref::H264 => "h264", video_select::CodecPref::H265 => "h265" }; | ||
| println!("encoder={:?} source={} codec_pref={codec} source={}", selection.encoder, video_select::encoder_source_label(selection.encoder_source), video_select::source_label(selection.codec_source)); | ||
| // Both subcommands wake the host. Encoder changes restart live desktop streams; codec changes are logged only. | ||
| match notify_host(libc::SIGUSR2) { | ||
| Ok(()) => println!("notified the running host"), | ||
| Err(_) => println!( | ||
| "host not running, or the running host is not this binary: takes effect the next time a desktop connection starts, or after restarting the service" | ||
| ), | ||
| } | ||
| if which == "set-codec" { | ||
| println!("takes effect the next time a desktop connection starts"); | ||
| } | ||
| Ok(()) | ||
| } | ||
|
|
||
| /// Signal the host recorded in host.pid only when `/proc/<pid>/exe` is exactly | ||
| /// `canonicalize(current_exe())`. A filename match is not enough: an older host | ||
| /// has no SIGUSR2 handler, and the default action terminates the process. | ||
| /// A replaced binary reads back as `… (deleted)` and does not match. | ||
| fn notify_host(signal: i32) -> Result<(), ()> { | ||
| let pid = std::fs::read_to_string(host_pid_path()) | ||
| .ok() | ||
| .and_then(|s| s.trim().parse::<i32>().ok()) | ||
| .filter(|p| *p > 1) | ||
| .ok_or(())?; | ||
| let exe = std::fs::read_link(format!("/proc/{pid}/exe")).map_err(|_| ())?; | ||
| let own = std::fs::canonicalize(std::env::current_exe().map_err(|_| ())?).map_err(|_| ())?; | ||
| if !same_host_binary(&exe, &own) { | ||
| return Err(()); | ||
| } | ||
| if unsafe { libc::kill(pid, signal) } == 0 { | ||
| Ok(()) | ||
| } else { | ||
| Err(()) | ||
| } | ||
| } | ||
|
|
||
| /// `/proc/<pid>/exe` must equal the canonical path of this binary. A trailing ` (deleted)` does not match. | ||
| fn same_host_binary(proc_exe: &std::path::Path, own: &std::path::Path) -> bool { | ||
| proc_exe == own | ||
| } | ||
|
|
||
| /// Explicit command words for set-encoder / set-codec. Empty and whitespace are illegal. | ||
| pub(crate) fn cli_pref_ok(which: &str, value: &str) -> bool { | ||
| let value = value.trim(); | ||
|
|
@@ -196,21 +232,85 @@ mod cli_exit_tests { | |
| assert_eq!(super::reject_cli(Some("set-encoder"), 3, super::cli_pref_ok("set-encoder", "")), Some(2)); | ||
| assert_eq!(super::reject_cli(Some("set-codec"), 3, super::cli_pref_ok("set-codec", " ")), Some(2)); | ||
| } | ||
|
|
||
| /// SIGUSR1 and SIGUSR2 are installed with no assist UI. `host.pid` is written only after both exist. | ||
| #[test] | ||
| fn signal_handlers_install_without_assist() { | ||
| let rt = tokio::runtime::Builder::new_current_thread().enable_all().build().unwrap(); | ||
| rt.block_on(async { | ||
| let _guard = crate::config::test_env_lock().lock().unwrap(); | ||
| let dir = | ||
| std::env::temp_dir().join(format!("uuremote-signal-test-{}", std::process::id())); | ||
| let _ = std::fs::remove_dir_all(&dir); | ||
| std::env::set_var("UU_CONFIG", dir.join("config.json")); | ||
| assert!(super::install_host_signals(None)); | ||
| let pid = std::fs::read_to_string(super::host_pid_path()).unwrap(); | ||
| assert_eq!(pid.trim(), std::process::id().to_string()); | ||
| std::env::remove_var("UU_CONFIG"); | ||
| let _ = std::fs::remove_dir_all(&dir); | ||
| }); | ||
| } | ||
|
|
||
| #[test] | ||
| fn sigusr2_requires_the_same_canonical_binary() { | ||
| let own = std::path::Path::new("/home/user/.local/bin/uuremote-server"); | ||
| assert!(super::same_host_binary(own, own)); | ||
| assert!(!super::same_host_binary( | ||
| std::path::Path::new("/tmp/unpack/uuremote-server"), | ||
| own | ||
| )); | ||
| assert!(!super::same_host_binary( | ||
| std::path::Path::new("/home/user/.local/bin/uuremote-server (deleted)"), | ||
| own | ||
| )); | ||
| } | ||
| } | ||
| /// SIGUSR1 (`uuremote-server show`) opens the host window. | ||
| /// SIGUSR2 (set-encoder, set-codec, or `kill -USR2`) re-reads host_settings. Encoder changes switch live desktop streams; codec changes are logged for the next connection. | ||
| /// The default action of either signal terminates the process, so both handlers are installed before `host.pid` is written. | ||
| /// SIGUSR2 is independent of remote assistance: `UU_REMOTE_ASSIST=0` and a failed assist setup still switch live encoders. | ||
| /// SIGUSR1 is installed first as a no-op so `show` cannot terminate a host that has no assist window yet. | ||
| fn install_host_signals(ui: Option<std::sync::Arc<assist::LocalUi>>) -> bool { | ||
| static USR1: std::sync::Once = std::sync::Once::new(); | ||
| static USR2: std::sync::Once = std::sync::Once::new(); | ||
| let mut usr1_ok = true; | ||
| USR1.call_once(|| { | ||
| match tokio::signal::unix::signal(tokio::signal::unix::SignalKind::user_defined1()) { | ||
| Ok(mut usr1) => { tokio::spawn(async move { while usr1.recv().await.is_some() {} }); } | ||
| Err(_) => usr1_ok = false, | ||
| } | ||
| }); | ||
| if !usr1_ok { return false; } | ||
| let mut usr2_ok = true; | ||
| USR2.call_once(|| { | ||
| match tokio::signal::unix::signal(tokio::signal::unix::SignalKind::user_defined2()) { | ||
| Ok(mut usr2) => { tokio::spawn(async move { while usr2.recv().await.is_some() { crate::video_select::publish_reload(); } }); } | ||
| Err(_) => usr2_ok = false, | ||
| } | ||
| }); | ||
| if !usr2_ok { return false; } | ||
| // Assist attaches later and replaces the no-op with the window. A second registration replaces the first. | ||
| if let Some(ui) = ui { | ||
| if let Ok(mut usr1) = tokio::signal::unix::signal(tokio::signal::unix::SignalKind::user_defined1()) { | ||
| tokio::spawn(async move { while usr1.recv().await.is_some() { ui.present(); } }); | ||
| } | ||
| } | ||
| write_host_pid(); | ||
| true | ||
| } | ||
|
|
||
| fn present_on_usr1(ui: std::sync::Arc<assist::LocalUi>) { | ||
| let _ = install_host_signals(Some(ui)); | ||
| } | ||
|
|
||
| fn host_pid_path() -> std::path::PathBuf { config::path().with_file_name("host.pid") } | ||
| /// Lets `uuremote-server show` find this host service to open its window (SIGUSR1). | ||
| fn write_host_pid() { | ||
| use std::os::unix::fs::OpenOptionsExt; | ||
| use std::io::Write; | ||
| let path = host_pid_path(); | ||
| if let Some(dir) = path.parent() { let _ = std::fs::create_dir_all(dir); } | ||
| if let Ok(mut f) = std::fs::OpenOptions::new().write(true).create(true).truncate(true).mode(0o600).open(path) { | ||
| let _ = write!(f, "{}", std::process::id()); | ||
| } | ||
| } | ||
|
|
@@ -521,6 +621,8 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> { | |
| virtual_audio::init(); | ||
| let _audio_cleanup=virtual_audio::Cleanup; | ||
| log::info!("Starting uu-remote-linux host v{}...", env!("CARGO_PKG_VERSION")); | ||
| // Before host.pid, and before assist: a missing or failed assist session must still handle SIGUSR2. | ||
| let _ = install_host_signals(None); | ||
|
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When the host runs with AGENTS.md reference: AGENTS.md:L133-L133 Useful? React with 👍 / 👎.
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Author
There was a problem hiding this comment. Fixed in 5911a80: |
||
| video::warm_auto_probe(); | ||
| video::check_ffmpeg_usable(); | ||
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For a host authenticated solely through
UU_*environment credentials, or using a freshUU_CONFIGparent, the config directory need not exist when startup first calls this function.write_host_pid()silently fails because it does not create the parent, yet this returns success and is never retried when assistance is disabled;set-encoderlater creates the directory forhost_settings.jsonbut finds no PID, so it cannot notify the running host. Create the parent before writing or propagate the failure for retry.AGENTS.md reference: AGENTS.md:L28-L29
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Fixed in 5911a80:
write_host_pidcreates the config directory before writinghost.pid.