refactor: setup child process pipe in Rust (#21579)

Avoid passing the fd into JS and back into Rust. Instead we setup the
child's end of the pipe directly using a special Rust op.

ext/node/lib.rs

@@ -30,6 +30,7 @@ mod path;
 mod polyfill;
 mod resolution;
 
+pub use ops::ipc::ChildPipeFd;
 pub use ops::v8::VM_CONTEXT_INDEX;
 pub use package_json::PackageJson;
 pub use path::PathClean;
@@ -313,6 +314,7 @@ deno_core::extension!(deno_node,
     ops::util::op_node_guess_handle_type,
     ops::crypto::op_node_create_private_key,
     ops::ipc::op_node_ipc_pipe,
+    ops::ipc::op_node_child_ipc_pipe,
     ops::ipc::op_node_ipc_write,
     ops::ipc::op_node_ipc_read,
   ],

ext/node/ops/ipc.rs

@@ -6,6 +6,8 @@ pub use unix::*;
 #[cfg(windows)]
 pub use windows::*;
 
+pub struct ChildPipeFd(pub i32);
+
 #[cfg(unix)]
 mod unix {
   use std::cell::RefCell;
@@ -46,6 +48,22 @@ mod unix {
     Ok(state.resource_table.add(IpcJsonStreamResource::new(fd)?))
   }
 
+  // Open IPC pipe from bootstrap options.
+  #[op2]
+  #[smi]
+  pub fn op_node_child_ipc_pipe(
+    state: &mut OpState,
+  ) -> Result<Option<ResourceId>, AnyError> {
+    let fd = match state.try_borrow_mut::<crate::ChildPipeFd>() {
+      Some(child_pipe_fd) => child_pipe_fd.0,
+      None => return Ok(None),
+    };
+
+    Ok(Some(
+      state.resource_table.add(IpcJsonStreamResource::new(fd)?),
+    ))
+  }
+
   #[op2(async)]
   pub async fn op_node_ipc_write(
     state: Rc<RefCell<OpState>>,
@@ -492,6 +510,12 @@ mod windows {
     Err(deno_core::error::not_supported())
   }
 
+  #[op2(fast)]
+  #[smi]
+  pub fn op_node_child_ipc_pipe() -> Result<i32, AnyError> {
+    Ok(-1)
+  }
+
   #[op2(async)]
   pub async fn op_node_ipc_write() -> Result<(), AnyError> {
     Err(deno_core::error::not_supported())

ext/node/polyfills/02_init.js

@@ -12,7 +12,6 @@ let initialized = false;
 function initialize(
   usesLocalNodeModulesDir,
   argv0,
-  ipcFd,
 ) {
   if (initialized) {
     throw Error("Node runtime already initialized");
@@ -38,7 +37,7 @@ function initialize(
   // but it's the only way to get `args` and `version` and this point.
   internals.__bootstrapNodeProcess(argv0, Deno.args, Deno.version);
   internals.__initWorkerThreads();
-  internals.__setupChildProcessIpcChannel(ipcFd);
+  internals.__setupChildProcessIpcChannel();
   // `Deno[Deno.internal].requireImpl` will be unreachable after this line.
   delete internals.requireImpl;
 }

ext/node/polyfills/child_process.ts

@@ -49,6 +49,7 @@ import {
 } from "ext:deno_node/internal/util.mjs";
 
 const { core } = globalThis.__bootstrap;
+const ops = core.ops;
 
 const MAX_BUFFER = 1024 * 1024;
 
@@ -822,7 +823,8 @@ export function execFileSync(
   return ret.stdout as string | Buffer;
 }
 
-function setupChildProcessIpcChannel(fd: number) {
+function setupChildProcessIpcChannel() {
+  const fd = ops.op_node_child_ipc_pipe();
   if (typeof fd != "number" || fd < 0) return;
   setupChannel(process, fd);
 }

runtime/js/99_main.js

@@ -440,7 +440,6 @@ function bootstrapMainRuntime(runtimeOptions) {
     3: inspectFlag,
     5: hasNodeModulesDir,
     6: maybeBinaryNpmCommandName,
-    7: nodeIpcFd,
   } = runtimeOptions;
 
   performance.setTimeOrigin(DateNow());
@@ -546,7 +545,7 @@ function bootstrapMainRuntime(runtimeOptions) {
   ObjectDefineProperty(globalThis, "Deno", util.readOnly(finalDenoNs));
 
   if (nodeBootstrap) {
-    nodeBootstrap(hasNodeModulesDir, maybeBinaryNpmCommandName, nodeIpcFd);
+    nodeBootstrap(hasNodeModulesDir, maybeBinaryNpmCommandName);
   }
 }
 

runtime/worker.rs

@@ -487,7 +487,16 @@ impl MainWorker {
   }
 
   pub fn bootstrap(&mut self, options: BootstrapOptions) {
-    self.js_runtime.op_state().borrow_mut().put(options.clone());
+    // Setup bootstrap options for ops.
+    {
+      let op_state = self.js_runtime.op_state();
+      let mut state = op_state.borrow_mut();
+      state.put(options.clone());
+      if let Some(node_ipc_fd) = options.node_ipc_fd {
+        state.put(deno_node::ChildPipeFd(node_ipc_fd));
+      }
+    }
+
     let scope = &mut self.js_runtime.handle_scope();
     let args = options.as_v8(scope);
     let bootstrap_fn = self.bootstrap_fn_global.take().unwrap();

runtime/worker_bootstrap.rs

@@ -117,8 +117,6 @@ struct BootstrapV8<'a>(
   bool,
   // maybe_binary_npm_command_name
   Option<&'a str>,
-  // node_ipc_fd
-  i32,
 );
 
 impl BootstrapOptions {
@@ -138,7 +136,6 @@ impl BootstrapOptions {
       self.enable_testing_features,
       self.has_node_modules_dir,
       self.maybe_binary_npm_command_name.as_deref(),
-      self.node_ipc_fd.unwrap_or(-1),
     );
 
     bootstrap.serialize(ser).unwrap()