fix(threads): a race condition, build-times, and warnings (#79)

* Fix a race condition, build-times, and warnings

* Yeah, yeah... I know

* style(code): add comment to explain race condition

Co-authored-by: Aram Drevekenin <aram@poor.dev>

Cargo.toml

@@ -20,12 +20,21 @@ bincode = "1.3.1"
 structopt = "0.3"
 serde_yaml = "0.8"
 serde_json = "1.0"
-wasmer = { git = "https://github.com/wasmerio/wasmer.git" }
-wasmer-wasi = { git = "https://github.com/wasmerio/wasmer.git" }
 
 [dependencies.async-std]
 version = "1.3.0"
 features = ["unstable"]
 
+[dependencies.wasmer]
+git = "https://github.com/wasmerio/wasmer.git"
+optional = true
+
+[dependencies.wasmer-wasi]
+git = "https://github.com/wasmerio/wasmer.git"
+optional = true
+
+[features]
+wasm-wip = ["wasmer", "wasmer-wasi"]
+
 [dev-dependencies]
 insta = "0.16.1"

src/main.rs

@@ -11,19 +11,15 @@ mod screen;
 mod terminal_pane;
 mod utils;
 
-use std::io::{self, Read, Write};
+use std::io::Write;
 use std::os::unix::net::UnixStream;
 use std::path::PathBuf;
 use std::sync::mpsc::{channel, Receiver, Sender};
-use std::sync::{Arc, Mutex};
 use std::thread;
 
 use serde::{Deserialize, Serialize};
 use structopt::StructOpt;
 
-use wasmer::{Exports, Function, Instance, Module, Store, Value};
-use wasmer_wasi::WasiState;
-
 use crate::command_is_executing::CommandIsExecuting;
 use crate::input::input_loop;
 use crate::layout::Layout;
@@ -257,13 +253,17 @@ pub fn start(mut os_input: Box<dyn OsApi>, opts: Opt) {
     // Here be dragons! This is very much a work in progress, and isn't quite functional
     // yet. It's being left out of the tests because is slows them down massively (by
     // recompiling a WASM module for every single test). Stay tuned for more updates!
-    #[cfg(not(test))]
+    #[cfg(feature = "wasm-wip")]
     active_threads.push(
         thread::Builder::new()
             .name("wasm".to_string())
             .spawn(move || {
                 // TODO: Clone shared state here
                 move || -> Result<(), Box<dyn std::error::Error>> {
+                    use std::io;
+                    use std::sync::{Arc, Mutex};
+                    use wasmer::{Exports, Function, Instance, Module, Store, Value};
+                    use wasmer_wasi::WasiState;
                     let store = Store::default();
 
                     println!("Compiling module...");
@@ -364,6 +364,7 @@ pub fn start(mut os_input: Box<dyn OsApi>, opts: Opt) {
     let _ipc_thread = thread::Builder::new()
         .name("ipc_server".to_string())
         .spawn({
+            use std::io::Read;
             let send_pty_instructions = send_pty_instructions.clone();
             let send_screen_instructions = send_screen_instructions.clone();
             move || {

src/pty_bus.rs

@@ -11,7 +11,7 @@ use std::path::PathBuf;
 
 use crate::layout::Layout;
 use crate::os_input_output::OsApi;
-use crate::utils::logging::{debug_log_to_file, debug_to_file};
+use crate::utils::logging::debug_to_file;
 use crate::ScreenInstruction;
 
 pub struct ReadFromPid {

src/screen.rs

@@ -380,9 +380,15 @@ impl Screen {
         }
     }
     pub fn handle_pty_event(&mut self, pid: RawFd, event: VteEvent) {
-        let terminal_output = self.terminals.get_mut(&pid).unwrap();
+        // if we don't have the terminal in self.terminals it's probably because
+        // of a race condition where the terminal was created in pty_bus but has not
+        // yet been created in Screen. These events are currently not buffered, so
+        // if you're debugging seemingly randomly missing stdout data, this is
+        // the reason
+        if let Some(terminal_output) = self.terminals.get_mut(&pid) {
             terminal_output.handle_event(event);
         }
+    }
     pub fn write_to_active_terminal(&mut self, mut bytes: Vec<u8>) {
         if let Some(active_terminal_id) = &self.get_active_terminal_id() {
             self.os_api

src/utils/logging.rs

@@ -23,14 +23,9 @@ pub fn atomic_create_dir(dir_name: &str) -> io::Result<()> {
     }
 }
 
-pub fn debug_log_to_file(message: String) -> io::Result<()> {
+pub fn debug_log_to_file(mut message: String) -> io::Result<()> {
-    atomic_create_file(MOSAIC_TMP_LOG_FILE);
+    message.push('\n');
-    let mut file = fs::OpenOptions::new()
+    debug_log_to_file_without_newline(message)
-        .append(true)
-        .create(true)
-        .open(MOSAIC_TMP_LOG_FILE)?;
-    file.write_all(message.as_bytes())?;
-    file.write_all(b"\n")
 }
 
 pub fn debug_log_to_file_without_newline(message: String) -> io::Result<()> {
@@ -39,9 +34,7 @@ pub fn debug_log_to_file_without_newline(message: String) -> io::Result<()> {
         .append(true)
         .create(true)
         .open(MOSAIC_TMP_LOG_FILE)?;
-    file.write_all(message.as_bytes())?;
+    file.write_all(message.as_bytes())
-
-    Ok(())
 }
 
 pub fn debug_log_to_file_pid_0(message: String, pid: RawFd) -> io::Result<()> {