.

test_util/src/spawn.rs

@@ -33,13 +33,21 @@ pub fn exec_replace_inner(
   use win32job::ExtendedLimitInfo;
   use win32job::Job;
 
-  // Creates a child process, and then assigns it to our current job. It would be more reliable
-  // to create the child suspended and then assign it to the job. For now, we create the child, create
-  // the job and then assign both us and the child to the job.
+  // Use a job to ensure the child process's lifetime does not exceed the current process's lifetime.
+  // This ensures that if the current process is terminated (e.g., via ctrl+c or task manager),
+  // the child process is automatically reaped.
 
+  // For more information about this technique, see Raymond Chen's blog post:
   // https://devblogs.microsoft.com/oldnewthing/20131209-00/?p=2433
+  // Note: While our implementation is not perfect, it serves its purpose for test code.
+
+  // In the future, we may directly obtain the main thread's handle from Rust code and use it
+  // to create a suspended process that we can then resume:
   // https://github.com/rust-lang/rust/issues/96723
 
+  // Creates a child process and assigns it to our current job.
+  // A more reliable approach would be to create the child suspended and then assign it to the job.
+  // For now, we create the child, create the job, and then assign both us and the child to the job.
   let mut child = Command::new(cmd).args(&args[1..]).spawn()?;
 
   let mut info = ExtendedLimitInfo::default();
@@ -53,8 +61,11 @@ pub fn exec_replace_inner(
   std::process::exit(exit.code().unwrap_or(1));
 }
 
-/// Runs a command, replacing the current process. On Windows, this function blocks and
+/// Runs a command, replacing the current process on Unix. On Windows, this function blocks and
 /// exits.
+///
+/// In either case, the only way this function returns is if it fails to launch the child
+/// process.
 pub fn exec_replace(command: &str, args: &[&str]) -> Result<Infallible, Error> {
   exec_replace_inner(command, args)
 }