From 14066e19b602c166d8e6ca7192b9354e86483f38 Mon Sep 17 00:00:00 2001
From: Suyono <suyono3484@gmail.com>
Date: Tue, 21 Nov 2023 13:19:04 +1100
Subject: [PATCH] wip: waiter

---
 Cargo.lock                    | 20 +++++++++++++++++++-
 Cargo.toml                    |  1 +
 src/bin/init.rs               | 11 +----------
 src/init.rs                   |  2 +-
 src/init/daemon.rs            | 20 ++++++++++++++++++++
 src/init/daemon/sighandler.rs | 31 +++++++++++++++++++++++++++++++
 src/init/daemon/waiter.rs     | 10 ++++++++++
 src/init/sighandler.rs        | 23 -----------------------
 8 files changed, 83 insertions(+), 35 deletions(-)
 create mode 100644 src/init/daemon.rs
 create mode 100644 src/init/daemon/sighandler.rs
 create mode 100644 src/init/daemon/waiter.rs
 delete mode 100644 src/init/sighandler.rs

diff --git a/Cargo.lock b/Cargo.lock
index 30c42b2..8009b84 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -44,6 +44,12 @@ version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
+[[package]]
+name = "bitflags"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "327762f6e5a765692301e5bb513e0d9fef63be86bbc14528052b1cd3e6f03e07"
+
 [[package]]
 name = "bytes"
 version = "1.5.0"
@@ -119,6 +125,17 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "nix"
+version = "0.27.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2eb04e9c688eff1c89d72b407f168cf79bb9e867a9d3323ed6c01519eb9cc053"
+dependencies = [
+ "bitflags 2.4.1",
+ "cfg-if",
+ "libc",
+]
+
 [[package]]
 name = "num_cpus"
 version = "1.16.0"
@@ -191,7 +208,7 @@ version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4722d768eff46b75989dd134e5c353f0d6296e5aaa3132e776cbdb56be7731aa"
 dependencies = [
- "bitflags",
+ "bitflags 1.3.2",
 ]
 
 [[package]]
@@ -354,5 +371,6 @@ checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
 name = "wingmate-rs"
 version = "0.1.0"
 dependencies = [
+ "nix",
  "tokio",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index b7bc4b1..60c7fab 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,4 +6,5 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+nix = {version = "0.27.1", features = ["process"]}
 tokio = { version = "1.34.0", features = ["full"] }
diff --git a/src/bin/init.rs b/src/bin/init.rs
index 42ebf59..8500fa4 100644
--- a/src/bin/init.rs
+++ b/src/bin/init.rs
@@ -1,17 +1,8 @@
 
 use std::error;
 use wingmate_rs::init;
-use tokio::task::{self, JoinHandle};
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn error::Error>> {
-    let sig_handler_fn: JoinHandle<Result<(), Box<dyn error::Error + Send + Sync>>> = task::spawn(async {
-        init::sighandler::sighandler().await
-    });
-
-    if let Err(v) = sig_handler_fn.await? {
-        return Err(v as Box<dyn error::Error>)
-    }
-
-    Ok(())
+    init::daemon::start().await
 }
\ No newline at end of file
diff --git a/src/init.rs b/src/init.rs
index ddfd3e5..7b1b652 100644
--- a/src/init.rs
+++ b/src/init.rs
@@ -1 +1 @@
-pub mod sighandler;
\ No newline at end of file
+pub mod daemon;
\ No newline at end of file
diff --git a/src/init/daemon.rs b/src/init/daemon.rs
new file mode 100644
index 0000000..a8f944b
--- /dev/null
+++ b/src/init/daemon.rs
@@ -0,0 +1,20 @@
+mod sighandler;
+mod waiter;
+
+use std::error;
+use tokio::task::{self, JoinHandle};
+use tokio::sync::watch;
+
+pub async fn start() -> Result<(), Box<dyn error::Error>> {
+    let (tx, mut _rx) = watch::channel::<i32>(1);
+
+    let sig_handler_fn: JoinHandle<Result<(), Box<dyn error::Error + Send + Sync>>> = task::spawn(async move {
+        sighandler::sighandler(tx).await
+    });
+
+    if let Err(v) = sig_handler_fn.await? {
+        return Err(v as Box<dyn error::Error>)
+    }
+
+    Ok(())
+}
\ No newline at end of file
diff --git a/src/init/daemon/sighandler.rs b/src/init/daemon/sighandler.rs
new file mode 100644
index 0000000..89e9708
--- /dev/null
+++ b/src/init/daemon/sighandler.rs
@@ -0,0 +1,31 @@
+use std::error;
+use tokio::signal::unix::{signal, SignalKind};
+use tokio::select;
+use tokio::sync::watch::Sender;
+
+pub async fn sighandler(s: Sender<i32>) -> Result<(), Box<dyn error::Error + Send + Sync>> {
+    let mut sigint = signal(SignalKind::interrupt())?; 
+    let mut sigterm = signal(SignalKind::terminate())?;
+    let mut sigchld = signal(SignalKind::child())?;
+
+    'signal: loop {
+        select! {
+            _ = sigint.recv() => {
+                println!("got SIGINT");
+                drop(s);
+                break 'signal;
+            },
+            _ = sigterm.recv() => {
+                println!("got SIGTERM");
+                drop(s);
+                break 'signal;
+            },
+            _ = sigchld.recv() => {
+                // do nothing intentionally
+                // return Err(())
+            },
+        }
+        }
+
+    Ok(())
+}
\ No newline at end of file
diff --git a/src/init/daemon/waiter.rs b/src/init/daemon/waiter.rs
new file mode 100644
index 0000000..bf4a29e
--- /dev/null
+++ b/src/init/daemon/waiter.rs
@@ -0,0 +1,10 @@
+use nix::sys::wait;
+use nix::unistd::Pid;
+
+#[allow(dead_code)]
+fn wait_all() {
+    match wait::waitpid(Pid::from_raw(-1), Some(wait::WaitPidFlag::WNOHANG)) {
+        Ok(_x) => {},
+        Err(_err) => {},
+    }
+}
\ No newline at end of file
diff --git a/src/init/sighandler.rs b/src/init/sighandler.rs
deleted file mode 100644
index f3e09fd..0000000
--- a/src/init/sighandler.rs
+++ /dev/null
@@ -1,23 +0,0 @@
-use std::error;
-use tokio::signal::unix::{signal, SignalKind};
-use tokio::select;
-
-#[allow(dead_code)]
-pub async fn sighandler() -> Result<(), Box<dyn error::Error + Send + Sync>> {
-    let mut sigint = signal(SignalKind::interrupt())?; 
-    let mut sigterm = signal(SignalKind::terminate())?;
-    let mut sigchld = signal(SignalKind::child())?;
-    select! {
-        _ = sigint.recv() => {
-            println!("got SIGINT");
-        },
-        _ = sigterm.recv() => {
-            println!("got SIGTERM");
-        },
-        _ = sigchld.recv() => {
-            // return Err(())
-        },
-    }
-
-    Ok(())
-}
\ No newline at end of file