HaikuDepot: Fix Crash on Quit During Load

If the system is currently loading-up and populating
data and the user quits then it was crashing because
of a call to a deleted ProcessCoordinator object.
This change implements the reference as BReference
ensuring that the ProcessCoordinator object is only
deleted after it is not used anywhere.

Resolves #16109

Change-Id: If535c151819da37d502283af3745e4148da69026
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2797
Reviewed-by: waddlesplash <[email protected]>

src/apps/haikudepot/server/AbstractProcess.cpp

@@ -36,7 +36,7 @@ void
 AbstractProcess::SetListener(AbstractProcessListener* listener)
 {
 	AutoLocker<BLocker> locker(&fLock);
-	fListener = listener;
+	fListener = BReference<AbstractProcessListener>(listener);
 }
 
 
@@ -64,7 +64,7 @@ AbstractProcess::Run()
 	if (runResult != B_OK)
 		printf("[%s] an error has arisen; %s\n", Name(), strerror(runResult));
 
-	AbstractProcessListener* listener;
+	BReference<AbstractProcessListener> listener;
 
 	{
 		AutoLocker<BLocker> locker(&fLock);
@@ -76,7 +76,7 @@ AbstractProcess::Run()
 	// this process may be part of a larger bulk-load process and
 	// if so, the process orchestration needs to know when this
 	// process has completed.
-	if (listener != NULL)
+	if (listener.Get() != NULL)
 		listener->ProcessExited();
 
 	return runResult;
@@ -110,7 +110,7 @@ status_t
 AbstractProcess::Stop()
 {
 	status_t result = B_CANCELED;
-    AbstractProcessListener* listener = NULL;
+    BReference<AbstractProcessListener> listener = NULL;
 
 	{
 		AutoLocker<BLocker> locker(&fLock);
@@ -126,7 +126,7 @@ AbstractProcess::Stop()
 		}
 	}
 
-	if (listener != NULL)
+	if (listener.Get() != NULL)
 		listener->ProcessExited();
 
 	return result;

src/apps/haikudepot/server/AbstractProcess.h

@@ -8,6 +8,7 @@
 #define ABSTRACT_PROCESS_H
 
 #include <String.h>
+#include <Referenceable.h>
 #include <Url.h>
 
 #include "StandardMetaData.h"
@@ -26,7 +27,7 @@ typedef enum process_state {
     failure.
  */
 
-class AbstractProcessListener {
+class AbstractProcessListener : public BReferenceable {
 public:
 	virtual	void				ProcessExited() = 0;
 };
@@ -55,7 +56,7 @@ protected:
 
 private:
 			BLocker				fLock;
-			AbstractProcessListener*
+			BReference<AbstractProcessListener>
 								fListener;
 			bool				fWasStopped;
 			process_state		fProcessState;

src/apps/haikudepot/ui/MainWindow.cpp

@@ -496,7 +496,7 @@ MainWindow::MessageReceived(BMessage* message)
 				}
 				_AddRemovePackageFromLists(ref);
 				if ((changes & PKG_CHANGED_STATE) != 0
-						&& fCoordinator == NULL) {
+						&& fCoordinator.Get() == NULL) {
 					fWorkStatusView->PackageStatusChanged(ref);
 				}
 			}
@@ -1334,14 +1334,14 @@ MainWindow::_AddProcessCoordinator(ProcessCoordinator* item)
 {
 	AutoLocker<BLocker> lock(&fCoordinatorLock);
 
-	if (fCoordinator == NULL) {
+	if (fCoordinator.Get() == NULL) {
 		if (acquire_sem(fCoordinatorRunningSem) != B_OK)
 			debugger("unable to acquire the process coordinator sem");
 		if (Logger::IsInfoEnabled()) {
 			printf("adding and starting a process coordinator [%s]\n",
 				item->Name().String());
 		}
-		fCoordinator = item;
+		fCoordinator = BReference<ProcessCoordinator>(item);
 		fCoordinator->Start();
 	}
 	else {
@@ -1364,7 +1364,7 @@ MainWindow::_SpinUntilProcessCoordinatorComplete()
 			debugger("unable to release the process coordinator sem");
 		{
 			AutoLocker<BLocker> lock(&fCoordinatorLock);
-			if (fCoordinator == NULL)
+			if (fCoordinator.Get() == NULL)
 				return;
 		}
 	}
@@ -1381,16 +1381,15 @@ MainWindow::_StopProcessCoordinators()
 		AutoLocker<BLocker> lock(&fCoordinatorLock);
 
 		while (!fCoordinatorQueue.empty()) {
-			ProcessCoordinator *processCoordinator = fCoordinatorQueue.front();
+			BReference<ProcessCoordinator> processCoordinator = fCoordinatorQueue.front();
 			if (Logger::IsInfoEnabled()) {
 				printf("will drop queued process coordinator [%s]\n",
 					processCoordinator->Name().String());
 			}
 			fCoordinatorQueue.pop();
-			delete processCoordinator;
 		}
 
-		if (fCoordinator != NULL) {
+		if (fCoordinator.Get() != NULL) {
 			fCoordinator->Stop();
 		}
 	}
@@ -1416,7 +1415,7 @@ MainWindow::CoordinatorChanged(ProcessCoordinatorState& coordinatorState)
 {
 	AutoLocker<BLocker> lock(&fCoordinatorLock);
 
-	if (fCoordinator == coordinatorState.Coordinator()) {
+	if (fCoordinator.Get() == coordinatorState.Coordinator()) {
 		if (!coordinatorState.IsRunning()) {
 			if (release_sem(fCoordinatorRunningSem) != B_OK)
 				debugger("unable to release the process coordinator sem");
@@ -1434,8 +1433,9 @@ MainWindow::CoordinatorChanged(ProcessCoordinatorState& coordinatorState)
 				messenger.SendMessage(message);
 			}
 
-			delete fCoordinator;
+			fCoordinator = BReference<ProcessCoordinator>(NULL);
-			fCoordinator = NULL;
+				// will delete the old process coordinator if it is not used
+				// elsewhere.
 
 			// now schedule the next one.
 			if (!fCoordinatorQueue.empty()) {

src/apps/haikudepot/ui/MainWindow.h

@@ -155,9 +155,10 @@ private:
 			Model				fModel;
 			ModelListenerRef	fModelListener;
 
-			std::queue<ProcessCoordinator*>
+			std::queue<BReference<ProcessCoordinator>>
 								fCoordinatorQueue;
-			ProcessCoordinator*	fCoordinator;
+			BReference<ProcessCoordinator>
+								fCoordinator;
 			BLocker				fCoordinatorLock;
 			sem_id				fCoordinatorRunningSem;