Merge pull request #499 from zellij-org/multiprocess

Switch to a multiprocess client-sever model

.gitignore

@@ -3,4 +3,5 @@
 .vscode
 .vim
 .DS_Store 
-/assets/man/zellij.1
+/assets/man/zellij.1
+**/target

Cargo.toml

@@ -15,6 +15,7 @@ include = ["src/**/*", "assets/plugins/*", "assets/layouts/*", "assets/config/*"
 ansi_term = "0.12.1"
 backtrace = "0.3.55"
 bincode = "1.3.1"
+daemonize = "0.4.1"
 directories-next = "2.0"
 futures = "0.3.5"
 libc = "0.2"

src/cli.rs

@@ -13,19 +13,23 @@ pub struct CliArgs {
     pub max_panes: Option<usize>,
 
     /// Change where zellij looks for layouts and plugins
-    #[structopt(long)]
+    #[structopt(long, parse(from_os_str))]
     pub data_dir: Option<PathBuf>,
 
+    /// Run server listening at the specified socket path
+    #[structopt(long, parse(from_os_str))]
+    pub server: Option<PathBuf>,
+
     /// Path to a layout yaml file
-    #[structopt(short, long)]
+    #[structopt(short, long, parse(from_os_str))]
     pub layout: Option<PathBuf>,
 
     /// Change where zellij looks for the configuration
-    #[structopt(short, long, env=ZELLIJ_CONFIG_FILE_ENV)]
+    #[structopt(short, long, env=ZELLIJ_CONFIG_FILE_ENV, parse(from_os_str))]
     pub config: Option<PathBuf>,
 
     /// Change where zellij looks for the configuration
-    #[structopt(long, env=ZELLIJ_CONFIG_DIR_ENV)]
+    #[structopt(long, env=ZELLIJ_CONFIG_DIR_ENV, parse(from_os_str))]
     pub config_dir: Option<PathBuf>,
 
     #[structopt(subcommand)]

src/client/mod.rs

@@ -4,30 +4,62 @@ pub mod pane_resizer;
 pub mod panes;
 pub mod tab;
 
-use serde::{Deserialize, Serialize};
-use std::io::Write;
+use std::env::current_exe;
+use std::io::{self, Write};
+use std::path::Path;
+use std::process::Command;
 use std::sync::mpsc;
 use std::thread;
 
 use crate::cli::CliArgs;
 use crate::common::{
     command_is_executing::CommandIsExecuting,
-    errors::{ClientContext, ContextType},
+    errors::ContextType,
     input::config::Config,
     input::handler::input_loop,
     input::options::Options,
+    ipc::{ClientToServerMsg, ServerToClientMsg},
     os_input_output::ClientOsApi,
     thread_bus::{SenderType, SenderWithContext, SyncChannelWithContext},
+    utils::consts::ZELLIJ_IPC_PIPE,
 };
-use crate::server::ServerInstruction;
 
 /// Instructions related to the client-side application and sent from server to client
-#[derive(Serialize, Deserialize, Debug, Clone)]
+#[derive(Debug, Clone)]
 pub enum ClientInstruction {
     Error(String),
     Render(Option<String>),
     UnblockInputThread,
     Exit,
+    ServerError(String),
+}
+
+impl From<ServerToClientMsg> for ClientInstruction {
+    fn from(instruction: ServerToClientMsg) -> Self {
+        match instruction {
+            ServerToClientMsg::Exit => ClientInstruction::Exit,
+            ServerToClientMsg::Render(buffer) => ClientInstruction::Render(buffer),
+            ServerToClientMsg::UnblockInputThread => ClientInstruction::UnblockInputThread,
+            ServerToClientMsg::ServerError(backtrace) => ClientInstruction::ServerError(backtrace),
+        }
+    }
+}
+
+fn spawn_server(socket_path: &Path) -> io::Result<()> {
+    let status = Command::new(current_exe()?)
+        .arg("--server")
+        .arg(socket_path)
+        .status()?;
+    if status.success() {
+        Ok(())
+    } else {
+        let msg = "Process returned non-zero exit code";
+        let err_msg = match status.code() {
+            Some(c) => format!("{}: {}", msg, c),
+            None => msg.to_string(),
+        };
+        Err(io::Error::new(io::ErrorKind::Other, err_msg))
+    }
 }
 
 pub fn start_client(mut os_input: Box<dyn ClientOsApi>, opts: CliArgs, config: Config) {
@@ -45,13 +77,16 @@ pub fn start_client(mut os_input: Box<dyn ClientOsApi>, opts: CliArgs, config: C
         .unwrap();
     std::env::set_var(&"ZELLIJ", "0");
 
+    #[cfg(not(test))]
+    spawn_server(&*ZELLIJ_IPC_PIPE).unwrap();
+
     let mut command_is_executing = CommandIsExecuting::new();
 
     let config_options = Options::from_cli(&config.options, opts.option.clone());
 
     let full_screen_ws = os_input.get_terminal_size_using_fd(0);
-    os_input.connect_to_server();
-    os_input.send_to_server(ServerInstruction::NewClient(
+    os_input.connect_to_server(&*ZELLIJ_IPC_PIPE);
+    os_input.send_to_server(ClientToServerMsg::NewClient(
         full_screen_ws,
         opts,
         config_options,
@@ -97,15 +132,26 @@ pub fn start_client(mut os_input: Box<dyn ClientOsApi>, opts: CliArgs, config: C
         .name("signal_listener".to_string())
         .spawn({
             let os_input = os_input.clone();
+            let send_client_instructions = send_client_instructions.clone();
             move || {
-                os_input.receive_sigwinch(Box::new({
-                    let os_api = os_input.clone();
-                    move || {
-                        os_api.send_to_server(ServerInstruction::TerminalResize(
-                            os_api.get_terminal_size_using_fd(0),
-                        ));
-                    }
-                }));
+                os_input.handle_signals(
+                    Box::new({
+                        let os_api = os_input.clone();
+                        move || {
+                            os_api.send_to_server(ClientToServerMsg::TerminalResize(
+                                os_api.get_terminal_size_using_fd(0),
+                            ));
+                        }
+                    }),
+                    Box::new({
+                        let send_client_instructions = send_client_instructions.clone();
+                        move || {
+                            send_client_instructions
+                                .send(ClientInstruction::Exit)
+                                .unwrap()
+                        }
+                    }),
+                );
             }
         })
         .unwrap();
@@ -114,47 +160,53 @@ pub fn start_client(mut os_input: Box<dyn ClientOsApi>, opts: CliArgs, config: C
         .name("router".to_string())
         .spawn({
             let os_input = os_input.clone();
-            move || {
-                loop {
-                    let (instruction, mut err_ctx) = os_input.recv_from_server();
-                    err_ctx.add_call(ContextType::Client(ClientContext::from(&instruction)));
-                    if let ClientInstruction::Exit = instruction {
-                        break;
+            let mut should_break = false;
+            move || loop {
+                let (instruction, err_ctx) = os_input.recv_from_server();
+                err_ctx.update_thread_ctx();
+                match instruction {
+                    ServerToClientMsg::Exit | ServerToClientMsg::ServerError(_) => {
+                        should_break = true;
                     }
-                    send_client_instructions.send(instruction).unwrap();
+                    _ => {}
+                }
+                send_client_instructions.send(instruction.into()).unwrap();
+                if should_break {
+                    break;
                 }
-                send_client_instructions
-                    .send(ClientInstruction::Exit)
-                    .unwrap();
             }
         })
         .unwrap();
 
-    #[warn(clippy::never_loop)]
+    let handle_error = |backtrace: String| {
+        os_input.unset_raw_mode(0);
+        let goto_start_of_last_line = format!("\u{1b}[{};{}H", full_screen_ws.rows, 1);
+        let restore_snapshot = "\u{1b}[?1049l";
+        let error = format!(
+            "{}\n{}{}",
+            goto_start_of_last_line, restore_snapshot, backtrace
+        );
+        let _ = os_input
+            .get_stdout_writer()
+            .write(error.as_bytes())
+            .unwrap();
+        std::process::exit(1);
+    };
+
     loop {
         let (client_instruction, mut err_ctx) = receive_client_instructions
             .recv()
             .expect("failed to receive app instruction on channel");
 
-        err_ctx.add_call(ContextType::Client(ClientContext::from(
-            &client_instruction,
-        )));
+        err_ctx.add_call(ContextType::Client((&client_instruction).into()));
         match client_instruction {
             ClientInstruction::Exit => break,
             ClientInstruction::Error(backtrace) => {
-                let _ = os_input.send_to_server(ServerInstruction::ClientExit);
-                os_input.unset_raw_mode(0);
-                let goto_start_of_last_line = format!("\u{1b}[{};{}H", full_screen_ws.rows, 1);
-                let restore_snapshot = "\u{1b}[?1049l";
-                let error = format!(
-                    "{}\n{}{}",
-                    goto_start_of_last_line, restore_snapshot, backtrace
-                );
-                let _ = os_input
-                    .get_stdout_writer()
-                    .write(error.as_bytes())
-                    .unwrap();
-                std::process::exit(1);
+                let _ = os_input.send_to_server(ClientToServerMsg::ClientExit);
+                handle_error(backtrace);
+            }
+            ClientInstruction::ServerError(backtrace) => {
+                handle_error(backtrace);
             }
             ClientInstruction::Render(output) => {
                 if output.is_none() {
@@ -172,7 +224,7 @@ pub fn start_client(mut os_input: Box<dyn ClientOsApi>, opts: CliArgs, config: C
         }
     }
 
-    let _ = os_input.send_to_server(ServerInstruction::ClientExit);
+    let _ = os_input.send_to_server(ClientToServerMsg::ClientExit);
     router_thread.join().unwrap();
 
     // cleanup();

src/common/errors.rs

@@ -19,12 +19,29 @@ const MAX_THREAD_CALL_STACK: usize = 6;
 use super::thread_bus::SenderWithContext;
 #[cfg(not(test))]
 use std::panic::PanicInfo;
+
+pub trait ErrorInstruction {
+    fn error(err: String) -> Self;
+}
+
+impl ErrorInstruction for ClientInstruction {
+    fn error(err: String) -> Self {
+        ClientInstruction::Error(err)
+    }
+}
+
+impl ErrorInstruction for ServerInstruction {
+    fn error(err: String) -> Self {
+        ServerInstruction::Error(err)
+    }
+}
+
 /// Custom panic handler/hook. Prints the [`ErrorContext`].
 #[cfg(not(test))]
-pub fn handle_panic(
-    info: &PanicInfo<'_>,
-    send_app_instructions: &SenderWithContext<ClientInstruction>,
-) {
+pub fn handle_panic<T>(info: &PanicInfo<'_>, sender: &SenderWithContext<T>)
+where
+    T: ErrorInstruction + Clone,
+{
     use backtrace::Backtrace;
     use std::{process, thread};
     let backtrace = Backtrace::new();
@@ -70,7 +87,7 @@ pub fn handle_panic(
         println!("{}", backtrace);
         process::exit(1);
     } else {
-        let _ = send_app_instructions.send(ClientInstruction::Error(backtrace));
+        let _ = sender.send(T::error(backtrace));
     }
 }
 
@@ -103,6 +120,11 @@ impl ErrorContext {
                 break;
             }
         }
+        self.update_thread_ctx()
+    }
+
+    /// Updates the thread local [`ErrorContext`].
+    pub fn update_thread_ctx(&self) {
         ASYNCOPENCALLS
             .try_with(|ctx| *ctx.borrow_mut() = *self)
             .unwrap_or_else(|_| OPENCALLS.with(|ctx| *ctx.borrow_mut() = *self));
@@ -333,13 +355,15 @@ pub enum ClientContext {
     Error,
     UnblockInputThread,
     Render,
+    ServerError,
 }
 
 impl From<&ClientInstruction> for ClientContext {
     fn from(client_instruction: &ClientInstruction) -> Self {
         match *client_instruction {
             ClientInstruction::Exit => ClientContext::Exit,
             ClientInstruction::Error(_) => ClientContext::Error,
+            ClientInstruction::ServerError(_) => ClientContext::ServerError,
             ClientInstruction::Render(_) => ClientContext::Render,
             ClientInstruction::UnblockInputThread => ClientContext::UnblockInputThread,
         }
@@ -350,22 +374,20 @@ impl From<&ClientInstruction> for ClientContext {
 #[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize)]
 pub enum ServerContext {
     NewClient,
-    Action,
     Render,
-    TerminalResize,
     UnblockInputThread,
     ClientExit,
+    Error,
 }
 
 impl From<&ServerInstruction> for ServerContext {
     fn from(server_instruction: &ServerInstruction) -> Self {
         match *server_instruction {
             ServerInstruction::NewClient(..) => ServerContext::NewClient,
-            ServerInstruction::Action(_) => ServerContext::Action,
-            ServerInstruction::TerminalResize(_) => ServerContext::TerminalResize,
             ServerInstruction::Render(_) => ServerContext::Render,
             ServerInstruction::UnblockInputThread => ServerContext::UnblockInputThread,
             ServerInstruction::ClientExit => ServerContext::ClientExit,
+            ServerInstruction::Error(_) => ServerContext::Error,
         }
     }
 }