switch to mio so we can not block

Cargo.lock

@@ -188,6 +188,20 @@ name = "fuchsia-cprng"
 version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "fuchsia-zircon"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "fuchsia-zircon-sys"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "getopts"
 version = "0.2.21"
@@ -196,11 +210,33 @@ dependencies = [
  "unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "iovec"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "kernel32-sys"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "lazycell"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "libc"
 version = "0.2.62"
@@ -214,6 +250,67 @@ dependencies = [
  "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "mio"
+version = "0.6.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "iovec 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)",
+ "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "mio-child-process"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.21 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio-extras 2.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "mio-extras"
+version = "2.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lazycell 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.21 (registry+https://github.com/rust-lang/crates.io-index)",
+ "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "miow"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ws2_32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "net2"
+version = "0.2.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "nodrop"
 version = "0.1.14"
@@ -357,6 +454,11 @@ dependencies = [
  "syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "slab"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "sup"
 version = "0.1.0"
@@ -367,6 +469,8 @@ dependencies = [
  "fern 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "getopts 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.21 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio-child-process 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -421,6 +525,11 @@ name = "unicode-xid"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "winapi"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "winapi"
 version = "0.3.8"
@@ -430,6 +539,11 @@ dependencies = [
  "winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "winapi-build"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "winapi-i686-pc-windows-gnu"
 version = "0.4.0"
@@ -451,6 +565,15 @@ dependencies = [
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "ws2_32-sys"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [metadata]
 "checksum approx 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "08abcc3b4e9339e33a3d0a5ed15d84a687350c05689d825e0f6655eef9e76a94"
 "checksum arrayref 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "0d382e583f07208808f6b1249e60848879ba3543f57c32277bf52d69c2f0f0ee"
@@ -476,10 +599,20 @@ dependencies = [
 "checksum failure_derive 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0bc225b78e0391e4b8683440bf2e63c2deeeb2ce5189eab46e2b68c6d3725d08"
 "checksum fern 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)" = "e69ab0d5aca163e388c3a49d284fed6c3d0810700e77c5ae2756a50ec1a4daaa"
 "checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
+"checksum fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2e9763c69ebaae630ba35f74888db465e49e259ba1bc0eda7d06f4a067615d82"
+"checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum getopts 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)" = "14dbbfd5c71d70241ecf9e6f13737f7b5ce823821063188d7e46c41d371eebd5"
+"checksum iovec 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b2b3ea6ff95e175473f8ffe6a7eb7c00d054240321b84c57051175fe3c1e075e"
+"checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+"checksum lazycell 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
 "checksum libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)" = "34fcd2c08d2f832f376f4173a231990fa5aef4e99fb569867318a227ef4c06ba"
 "checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
+"checksum mio 0.6.21 (registry+https://github.com/rust-lang/crates.io-index)" = "302dec22bcf6bae6dfb69c647187f4b4d0fb6f535521f7bc022430ce8e12008f"
+"checksum mio-child-process 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "93e2c2ad8adb5feea8031c9b23b17e359dd65a75b32214660686edec80be0bf4"
+"checksum mio-extras 2.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "52403fe290012ce777c4626790c8951324a2b9e3316b3143779c72b029742f19"
+"checksum miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8c1f2f3b1cf331de6896aabf6e9d55dca90356cc9960cca7eaaf408a355ae919"
+"checksum net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)" = "42550d9fb7b6684a6d404d9fa7250c2eb2646df731d1c06afc06dcee9e1bcf88"
 "checksum nodrop 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)" = "72ef4a56884ca558e5ddb05a1d1e7e1bfd9a68d9ed024c21704cc98872dae1bb"
 "checksum num-integer 0.1.41 (registry+https://github.com/rust-lang/crates.io-index)" = "b85e541ef8255f6cf42bbfe4ef361305c6c135d10919ecc26126c4e5ae94bc09"
 "checksum num-traits 0.1.43 (registry+https://github.com/rust-lang/crates.io-index)" = "92e5113e9fd4cc14ded8e499429f396a20f98c772a47cc8622a736e1ec843c31"
@@ -498,13 +631,17 @@ dependencies = [
 "checksum rustc-demangle 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)" = "4c691c0e608126e00913e33f0ccf3727d5fc84573623b8d65b2df340b5201783"
 "checksum serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)" = "9796c9b7ba2ffe7a9ce53c2287dfc48080f4b2b362fcc245a259b3a7201119dd"
 "checksum serde_derive 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)" = "4b133a43a1ecd55d4086bd5b4dc6c1751c68b1bfbeba7a5040442022c7e7c02e"
+"checksum slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 "checksum syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "66850e97125af79138385e9b88339cbcd037e3f28ceab8c5ad98e64f0f1f80bf"
 "checksum synstructure 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3f085a5855930c0441ca1288cf044ea4aecf4f43a91668abdb870b4ba546a203"
 "checksum time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "db8dcfca086c1143c9270ac42a2bbd8a7ee477b78ac8e45b19abfb0cbede4b6f"
 "checksum toml 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "c7aabe75941d914b72bf3e5d3932ed92ce0664d49d8432305a8b547c37227724"
 "checksum unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "7007dbd421b92cc6e28410fe7362e2e0a2503394908f417b68ec8d1c364c4e20"
 "checksum unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
+"checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 "checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
+"checksum winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2d315eee3b34aca4797b2da6b13ed88266e6d612562a0c46390af8299fc699bc"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 "checksum winconsole 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3ef84b96d10db72dd980056666d7f1e7663ce93d82fa33b63e71c966f4cf5032"
+"checksum ws2_32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d59cefebd0c892fa2dd6de581e937301d8552cb44489cdff035c6187cb63fa5e"

Cargo.toml

@@ -11,6 +11,8 @@ dirs = "2.0"
 fern = { version = "0.5", features = ["colored"] }
 getopts = "0.2"
 log = "0.4"
+mio = "0.6"
+mio-child-process = "0.2"
 serde = "1.0"
 serde_derive = "1.0"
 toml = "0.5"

src/app.rs

@@ -2,19 +2,29 @@ use std::process::{Command, ExitStatus};
 
 use crate::result::Result;
 
+/// structure to define an app config
 #[derive(Clone, Debug, Deserialize)]
 pub struct App {
+	/// name of the app
 	pub name: String,
+	/// path/command to run
 	pub command: String,
+	/// arguments
 	pub args: Vec<String>,
+	/// should the app be restarted if it exits successfully
 	pub restart_on_success: Option<bool>,
+	/// should the app be restarted if it exits unsuccessfully
 	pub restart_on_failure: Option<bool>,
+	/// should the app be restarted if it is terminated
 	pub restart_on_terminate: Option<bool>,
+	/// on sup startup, should we wait for this app to run before continuting
 	pub wait: Option<bool>,
+	/// should this app keep sup from exiting, if it's running
 	pub hold: Option<bool>,
 }
 
 impl App {
+	/// start the application and wait for it to exit
 	pub fn wait_start(&self) -> Result<()> {
 		info!("starting application {}", &self.name);
 
@@ -41,7 +51,8 @@ impl App {
 		}
 	}
 
-	pub fn handle_exit(&self, status: ExitStatus) -> bool {
+	/// see if the app should be restarted
+	pub fn check_restart(&self, status: ExitStatus) -> bool {
 		if status.success() {
 			info!("application exited: {}", &self.name);
 			self.restart_on_success.unwrap_or(false)

src/apps.rs

@@ -3,6 +3,8 @@ use std::fs::File;
 use std::io::Read;
 use std::path::PathBuf;
 
+use mio::{Poll, PollOpt, Ready};
+
 use crate::app::App;
 use crate::proc::Proc;
 use crate::result::Result;
@@ -13,8 +15,10 @@ pub struct Apps {
 }
 
 impl Apps {
+	/// load apps from toml file
 	pub fn load(p: PathBuf) -> Result<Self> {
 		let path: String = p.display().to_string();
+
 		match File::open(p) {
 			Ok(mut file) => {
 				let mut buf = String::new();
@@ -43,10 +47,12 @@ impl Apps {
 		self.app.clone()
 	}
 
-	pub fn start(&self) -> (Vec<Proc>, Option<i8>) {
+	pub fn start(&self) -> (Vec<Proc>, Option<i8>, Poll) {
 		let mut procs: Vec<Proc> = Vec::new();
 		let mut holds: Option<i8> = None;
 
+		let poll = Poll::new().unwrap();
+
 		for app in self.apps() {
 			if app.wait.unwrap_or(false) {
 				if let Err(e) = app.wait_start() {
@@ -60,6 +66,8 @@ impl Apps {
 						if proc.app.hold.unwrap_or(false) {
 							holds = Some(holds.unwrap_or(0) + 1);
 						}
+						poll.register(&proc.process, proc.token, Ready::all(), PollOpt::edge())
+							.unwrap();
 						procs.push(proc);
 					}
 					Err(e) => {
@@ -70,60 +78,8 @@ impl Apps {
 			}
 		}
 
-		(procs, holds)
+		info!("holds: {:?}", holds);
-	}
-
-	pub fn run(&self, procs: Vec<Proc>, holds: Option<i8>) -> Result<Vec<Proc>> {
-		let mut procs = procs;
-		let mut holds = holds;
-
-		if holds.unwrap_or(0) < 1 {
-			error!("no holds configured");
-			return Ok(procs);
-		}
-
-		while holds > Some(0) {
-			let mut newprocs: Vec<Proc> = Vec::new();
-
-			while let Some(mut proc) = procs.pop() {
-				match proc.child.try_wait() {
-					Ok(Some(status)) => {
-						let hold = proc.app.hold.unwrap_or(false);
-						if proc.app.handle_exit(status) {
-							let name = proc.app.name.clone();
-							match Proc::start(proc.app) {
-								Ok(p) => newprocs.push(p),
-								Err(e) => {
-									error!("error restarting {}", name);
-									error!("{:?}", e);
-									if hold {
-										holds = Some(holds.unwrap_or(0) - 1);
-									}
-								}
-							};
-						} else if hold {
-							holds = Some(holds.unwrap_or(0) - 1);
-						}
-					}
-					Ok(None) => {
-						if let Some(s) = &proc.check_stdout() {
-							for line in s.lines() {
-								info!("[{}] stdout: {}", &proc.app.name, line);
-							}
-						}
-						if let Some(s) = &proc.check_stderr() {
-							for line in s.lines() {
-								info!("[{}] stderr: {}", &proc.app.name, line);
-							}
-						}
-						newprocs.push(proc);
-					}
-					Err(e) => error!("error: {:?}", e),
-				}
-			}
-			procs = newprocs;
-		}
 
-		Ok(procs)
+		(procs, holds, poll)
 	}
 }

src/config.rs

@@ -54,7 +54,7 @@ impl Config {
 		let log_file = if let Some(f) = matches.opt_str("f") {
 			PathBuf::from(f)
 		} else {
-			let mut p = PathBuf::new();
+			let mut p = PathBuf::from(&config_directory);
 			p.push("sup.log");
 			p
 		};

src/logger.rs

@@ -2,13 +2,13 @@ use std::path::PathBuf;
 
 use chrono::Local;
 use colored::Colorize;
-use fern::{Dispatch, log_file};
 use fern::colors::{Color, ColoredLevelConfig};
+use fern::{log_file, Dispatch};
 use log::LevelFilter;
 
 use crate::result::Result;
 
-pub fn setup_logger(logfile: PathBuf, level: LevelFilter) -> Result<()> {
+pub fn setup(logfile: PathBuf, level: LevelFilter) -> Result<()> {
 	Dispatch::new()
 		.format(|out, message, record| {
 			let colors = ColoredLevelConfig::new()
@@ -20,7 +20,11 @@ pub fn setup_logger(logfile: PathBuf, level: LevelFilter) -> Result<()> {
 
 			out.finish(format_args!(
 				"{} {} {}",
-				Local::now().format("%Y-%m-%dT%H:%M:%S%.3f%z").to_string().white().bold(),
+				Local::now()
+					.format("%Y-%m-%dT%H:%M:%S%.3f%z")
+					.to_string()
+					.white()
+					.bold(),
 				colors.color(record.level()),
 				message
 			))

src/main.rs

@@ -5,6 +5,8 @@ extern crate fern;
 extern crate getopts;
 #[macro_use]
 extern crate log;
+extern crate mio;
+extern crate mio_child_process;
 extern crate serde;
 #[macro_use]
 extern crate serde_derive;
@@ -16,6 +18,7 @@ mod config;
 mod logger;
 mod proc;
 mod result;
+mod run;
 
 use std::path::PathBuf;
 
@@ -23,11 +26,12 @@ use apps::Apps;
 use config::Config;
 use proc::Proc;
 use result::Result;
+use run::run;
 
 fn main() {
 	let config = Config::from_args();
 
-	if let Err(e) = logger::setup_logger(config.log_file, config.log_level) {
+	if let Err(e) = logger::setup(config.log_file, config.log_level) {
 		println!("FATAL: Error initializing logger: {:?}", e);
 		std::process::exit(1);
 	}
@@ -51,7 +55,7 @@ fn main() {
 
 fn startup(apps_file: PathBuf) -> Result<Vec<Proc>> {
 	let apps = Apps::load(apps_file)?;
-	let (procs, holds) = apps.start();
+	let (procs, holds, poll) = apps.start();
-	let procs = apps.run(procs, holds)?;
+	let procs = run(procs, holds, poll)?;
 	Ok(procs)
 }

src/proc.rs

@@ -1,12 +1,16 @@
-use std::io::Read;
+use std::convert::TryInto;
-use std::process::{Child, Command, Stdio};
+use std::process::{Command, Stdio};
+
+use mio::Token;
+use mio_child_process::{CommandAsync, Process};
 
 use crate::app::App;
 use crate::result::Result;
 
 pub struct Proc {
 	pub app: App,
-	pub child: Child,
+	pub process: Process,
+	pub token: Token,
 }
 
 impl Proc {
@@ -18,55 +22,18 @@ impl Proc {
 		command.stderr(Stdio::piped());
 		command.args(&app.args);
 
-		let child = command.spawn()?;
+		let process = command.spawn_async()?;
+		let token = Token(process.id().try_into()?);
 
-		Ok(Proc { app, child })
+		Ok(Proc {
+			app,
+			process,
+			token,
+		})
 	}
 
 	pub fn stop(&mut self) {
 		info!("stopping {}", &self.app.name);
-		let _ = self.child.kill();
+		let _ = self.process.kill();
-	}
-
-	pub fn check_stdout(&mut self) -> Option<String> {
-		let child_stdout = self.child.stdout.as_mut();
-		if let Some(stdout) = child_stdout {
-			let mut buf = String::new();
-			match stdout.read_to_string(&mut buf) {
-				Ok(size) => {
-					if size > 0 {
-						return Some(buf);
-					} else {
-						return None;
-					}
-				}
-				Err(e) => {
-					error!("couldn't read stdout from {}: {:?}", &self.app.name, e);
-					return None;
-				}
-			}
-		}
-		None
-	}
-
-	pub fn check_stderr(&mut self) -> Option<String> {
-		let child_stderr = self.child.stderr.as_mut();
-		if let Some(stderr) = child_stderr {
-			let mut buf = String::new();
-			match stderr.read_to_string(&mut buf) {
-				Ok(size) => {
-					if size > 0 {
-						return Some(buf);
-					} else {
-						return None;
-					}
-				}
-				Err(e) => {
-					error!("couldn't read stderr from {}: {:?}", &self.app.name, e);
-					return None;
-				}
-			}
-		}
-		None
 	}
 }

src/run.rs

@@ -0,0 +1,103 @@
+use std::sync::mpsc::TryRecvError;
+
+use mio::{Events, Poll, PollOpt, Ready, Token};
+use mio_child_process::{ProcessEvent, StdioChannel};
+
+use crate::proc::Proc;
+use crate::result::Result;
+
+/// check for holds and start the loop
+pub fn run(procs: Vec<Proc>, holds: Option<i8>, poll: Poll) -> Result<Vec<Proc>> {
+	if holds.unwrap_or(0) < 1 {
+		error!("no holds configured");
+		return Ok(procs);
+	}
+
+	Ok(run_loop(procs, holds, poll))
+}
+
+/// restart an App, return the new Proc or report error
+fn restart_app(proc: Proc) -> Result<Proc> {
+	let app = proc.app.clone();
+	let name = proc.app.name.clone();
+
+	match Proc::start(app) {
+		Ok(p) => Ok(p),
+		Err(e) => {
+			error!("error restarting {}", name);
+			error!("{:?}", e);
+			Err(e)
+		}
+	}
+}
+
+fn find_proc_by_token(token: Token, procs: &[Proc]) -> Option<usize> {
+	for (counter, proc) in procs.iter().enumerate() {
+		if proc.token == token {
+			return Some(counter);
+		}
+	}
+
+	None
+}
+
+fn process_event_data(channel: StdioChannel, data: String, app_name: &str) {
+	let c = match channel {
+		StdioChannel::Stdout => "stdout",
+		StdioChannel::Stderr => "stderr",
+	};
+
+	info!("[{}] {}: {}", c, app_name, data);
+}
+
+/// run the main loop until out of holds
+fn run_loop(procs: Vec<Proc>, holds: Option<i8>, poll: Poll) -> Vec<Proc> {
+	let mut procs = procs;
+	let mut holds = holds;
+
+	let mut events = Events::with_capacity(1024);
+
+	while holds > Some(0) {
+		poll.poll(&mut events, None).unwrap();
+
+		for event in events.iter() {
+			if let Some(i) = find_proc_by_token(event.token(), &procs) {
+				let mut proc = procs.remove(i);
+
+				match proc.process.try_recv() {
+					Ok(ProcessEvent::Data(channel, data)) => {
+						process_event_data(channel, data, &proc.app.name);
+						procs.push(proc);
+					}
+					Ok(ProcessEvent::CommandError(e)) => {
+						error!("[{}]: command error: {:?}", &proc.app.name, e)
+					}
+					Ok(ProcessEvent::IoError(channel, e)) => {
+						error!("[{}]: io error on {:?}: {:?}", &proc.app.name, channel, e)
+					}
+					Ok(ProcessEvent::Utf8Error(channel, e)) => {
+						error!("[{}]: utf8 error on {:?}: {:?}", &proc.app.name, channel, e)
+					}
+					Ok(ProcessEvent::Exit(status)) => {
+						let hold = proc.app.hold.unwrap_or(false);
+						if proc.app.check_restart(status) {
+							if let Ok(p) = restart_app(proc) {
+								poll.register(&p.process, p.token, Ready::all(), PollOpt::edge())
+									.unwrap();
+								procs.push(p);
+							} else if hold {
+								holds = Some(holds.unwrap_or(0) - 1);
+							}
+						} else if hold {
+							holds = Some(holds.unwrap_or(0) - 1);
+						}
+					}
+					Err(TryRecvError::Empty) => {}
+					Err(TryRecvError::Disconnected) => {}
+				};
+			}
+		}
+	}
+
+	procs
+}