Defer IWorkspace service registration onto a background job

[vogella]

Summary

• context.registerService(IWorkspace.class, workspace, null) dispatches ServiceEvent.REGISTERED synchronously to every ServiceTracker<IWorkspace> listener. Several listeners (e.g. save-participant registrations in DebugPlugin, LaunchingPlugin) do non-trivial work that blocks the startup critical path by ~250 ms on a medium workspace.
• Schedule the registration on a system Job so the fan-out runs off the main thread. removedService now joins the job before unregistering to preserve shutdown ordering.
• ResourcesPlugin.getWorkspace() is unaffected — it reads the field directly rather than going through the OSGi service.

Test plan

• Re-measure startup with the existing instrumentation: expect openInstanceLocationTracker leaf (~257 ms) to drop near zero, with the work reappearing off the critical path.
• Verify startup.complete headline drops by a comparable amount; if not, something downstream is serialized on the IWorkspace service.
• Exercise shutdown (bundle stop / framework stop) to confirm removedService joins the job correctly with no spurious warnings.
• Run org.eclipse.core.tests.resources bundle test suite.
• Smoke test: launch IDE, confirm save participants still run (e.g. Debug, JDT Launching) by invoking a workspace save.

🤖 Generated with Claude Code

[gemini-code-assist]

Code Review

This pull request updates ResourcesPlugin to perform IWorkspace service registration asynchronously, optimizing the startup path. The review feedback suggests enhancing the lifecycle management of the registration job by checking for cancellation within the task, explicitly canceling the job during service removal, and clearing service registration references to prevent potential leaks or stale states.

[gemini-code-assist]

To prevent potential service leaks during rapid startup/shutdown or service removal, the background job should check if it has been canceled before proceeding with the service registration. This works in conjunction with calling job.cancel() in removedService.

Suggested change

	Job job = Job.create("Register IWorkspace service", (IProgressMonitor monitor) -> { //$NON-NLS-1$
	Workspace ws = workspace;
	if (ws != null) {
	try {
	workspaceRegistration = context.registerService(IWorkspace.class, ws, null);
	} catch (IllegalStateException e) {
	// bundle context became invalid during shutdown
	}
	}
	return Status.OK_STATUS;
	});
	Job job = Job.create("Register IWorkspace service", (IProgressMonitor monitor) -> { //$NON-NLS-1$
	Workspace ws = workspace;
	if (ws != null && !monitor.isCanceled()) {
	try {
	workspaceRegistration = context.registerService(IWorkspace.class, ws, null);
	} catch (IllegalStateException e) {
	// bundle context became invalid during shutdown
	}
	}
	return Status.OK_STATUS;
	});

[gemini-code-assist]

It is recommended to cancel the registration job before joining it to ensure that if the job hasn't started yet, it won't run at all. Additionally, nulling out the registration fields after unregistering is a good practice to avoid stale references and potential double-unregistration issues.

				Job job = workspaceRegistrationJob;
				if (job != null) {
					job.cancel();
					try {
						job.join();
					} catch (InterruptedException e) {
						Thread.currentThread().interrupt();
					}
					workspaceRegistrationJob = null;
				}
				ServiceRegistration<IWorkspace> registration = workspaceRegistration;
				if (registration != null) {
					workspaceRegistration = null;
					try {
						registration.unregister();
					} catch (RuntimeException e) {
						getLog().log(Status.warning("Unregistering workspaces throws an exception", e)); //$NON-NLS-1$
					}
				}