Better handling of ready: true.

fixtures/async/container/a_container.rb

@@ -107,6 +107,27 @@ module Container
 						)
 					end
 				end
+
+				it "can exec with ready: true without premature termination" do
+					container.spawn(restart: false) do |instance|
+						# Using exec with ready: true should not cause the process to be killed
+						# by hang prevention, even though the notification pipe stays open.
+						instance.exec("sleep", "1", ready: true)
+					end
+
+					# Wait for the process to become ready:
+					container.wait_until_ready
+
+					# Sleep longer than the hang prevention timeout (0.1s) to verify
+					# the process isn't prematurely killed:
+					sleep(0.2)
+
+					# The process should still be running (not killed by hang prevention):
+					expect(container).to be(:running?)
+
+					# Now stop the container:
+					container.stop(false)
+				end
 			end
 
 			with "#sleep" do

lib/async/container/forked.rb

@@ -80,13 +80,15 @@ def name
 					# This method replaces the child process with the new executable, thus this method never returns.
 					#
 					# @parameter arguments [Array] The arguments to pass to the new process.
-					# @parameter ready [Boolean] If true, informs the parent process that the child is ready. Otherwise, the child process will need to use a notification protocol to inform the parent process that it is ready.
+					# @parameter ready [Boolean] If true, informs the parent process that the child is ready before exec. The notification pipe will still be passed to the exec'd process to prevent premature termination.
 					# @parameter options [Hash] Additional options to pass to {::Process.exec}.
 					def exec(*arguments, ready: true, **options)
+						# Always set up the notification pipe to be inherited by the exec'd process.
+						# This prevents the pipe from closing, which would trigger hang prevention and SIGKILL.
+						self.before_spawn(arguments, options)
+
 						if ready
 							self.ready!(status: "(exec)")
-						else
-							self.before_spawn(arguments, options)
 						end
 
 						::Process.exec(*arguments, **options)

lib/async/container/threaded.rb

@@ -91,10 +91,11 @@ def name
 					# Execute a child process using {::Process.spawn}. In order to simulate {::Process.exec}, an {Exit} instance is raised to propagage exit status.
 					# This creates the illusion that this method does not return (normally).
 					def exec(*arguments, ready: true, **options)
+						# Always set up the notification pipe to be inherited by the spawned process.
+						self.before_spawn(arguments, options)
+
 						if ready
 							self.ready!(status: "(spawn)")
-						else
-							self.before_spawn(arguments, options)
 						end
 
 						begin

releases.md

@@ -1,5 +1,9 @@
 # Releases
 
+## Unreleased
+
+  - **Fixed**: `instance.exec` with `ready: true` no longer causes premature termination. The notification pipe is now always passed to the exec'd process.
+
 ## v0.34.4
 
   - Add missing `bake` and `context` files to the release.