Crash SourceKitService to restart it

Shutdown an re-initialize would (sometimes?) give us back the previous XPC connection. The crash request is working even if SourceKit is busy fulfilling other requests and is guaranteed to spawn a new process.

Author: ahoppen

SourceKitStressTester/Sources/StressTester/SourceKitDocument.swift

@@ -457,9 +457,10 @@ class SourceKitDocument {
     case .timedOut:
       /// We timed out waiting for the response. Any following requests would
       /// not be executed by SourceKit until this one finishes. To avoid this,
-      /// and since we don't have cancellation support in SourceKit, set up a
-      /// new connection that is free to execute requests.
-      connection.restart()
+      /// and since we don't have cancellation support in SourceKit, crash the
+      /// current SourceKitService so we get a new instance that isn't
+      /// processing any requests.
+      connection.crash()
       throw SourceKitError.timedOut(request: info)
     }
   }

SourceKitStressTester/Sources/SwiftSourceKit/SourcekitdClient.swift

@@ -83,19 +83,15 @@ public class SourceKitdService {
     sourcekitd_shutdown()
   }
 
-  /// Restarts the service. This is a workaround to set up a new service in case
+  /// Crash the service. This is a workaround to set up a new service in case
   /// we time out waiting for a request response and we want to handle it.
   /// Replace by proper cancellation once we have cancellation support in
   /// SourceKit.
-  public func restart() {
-    sourcekitd_shutdown()
-    // We need to wait for the old service to fully shut down before we can
-    // create a new one but we don't receive a notification when the old service
-    // did shut down. Waiting for a second seems to give it enough time.
-    sleep(1)
-    initializeService()
+  public func crash() {
+    let request = SourceKitdRequest(uid: .request_CrashWithExit)
+    _ = sourcekitd_send_request_sync(request.rawRequest)
     stateQueue.sync {
-      self.state = .running
+      self.state = .interrupted
     }
   }