Changed the somewhat bold BLocker usage to a more straight forward semaphore

based mechanism to pause and eventually cancel the WorkerThread. This also works
now when the CopyEngine is still collecting file informartion (ticket #4153).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31912 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/installer/CopyEngine.cpp

@@ -26,6 +26,39 @@
 using std::nothrow;
 
 
+// SemaphoreLocking
+class SemaphoreLocking {
+public:
+	inline bool Lock(sem_id* lockable)
+	{
+		return acquire_sem(*lockable) == B_OK;
+	}
+
+	inline void Unlock(sem_id* lockable)
+	{
+		release_sem(*lockable);
+	}
+};
+
+// SemaphoreLocker
+class SemaphoreLocker : public AutoLocker<sem_id, SemaphoreLocking> {
+public:
+	inline SemaphoreLocker(sem_id semaphore, bool alreadyLocked = false,
+			bool lockIfNotLocked = true)
+		:
+		AutoLocker<sem_id, SemaphoreLocking>(),
+		fSem(semaphore)
+	{
+		SetTo(&fSem, alreadyLocked, lockIfNotLocked);
+	}
+
+private:
+	sem_id	fSem;
+};
+
+
+
+
 CopyEngine::CopyEngine(const BMessenger& messenger, BMessage* message)
 	:
 	fBufferQueue(),
@@ -102,16 +135,16 @@ CopyEngine::ResetTargets()
 
 
 status_t
-CopyEngine::CollectTargets(const char* source)
+CopyEngine::CollectTargets(const char* source, sem_id cancelSemaphore)
 {
 	int32 level = 0;
-	return _CollectCopyInfo(source, level);
+	return _CollectCopyInfo(source, level, cancelSemaphore);
 }
 
 
 status_t
 CopyEngine::CopyFolder(const char* source, const char* destination,
-	BLocker* locker)
+	sem_id cancelSemaphore)
 {
 	printf("%lld bytes to read in %lld files\n", fBytesToCopy, fItemsToCopy);
 
@@ -122,16 +155,16 @@ CopyEngine::CopyFolder(const char* source, const char* destination,
 	}
 
 	int32 level = 0;
-	return _CopyFolder(source, destination, level, locker);
+	return _CopyFolder(source, destination, level, cancelSemaphore);
 }
 
 
 status_t
 CopyEngine::CopyFile(const BEntry& _source, const BEntry& _destination,
-	BLocker* locker)
+	sem_id cancelSemaphore)
 {
-	AutoLocker<BLocker> lock(locker);
-	if (locker != NULL && !lock.IsLocked()) {
+	SemaphoreLocker lock(cancelSemaphore);
+	if (cancelSemaphore >= 0 && !lock.IsLocked()) {
 		// We are supposed to quit
 printf("CopyFile - cancled\n");
 		return B_CANCELED;
@@ -210,7 +243,8 @@ printf("CopyFile - cancled\n");
 
 
 status_t
-CopyEngine::_CollectCopyInfo(const char* _source, int32& level)
+CopyEngine::_CollectCopyInfo(const char* _source, int32& level,
+	sem_id cancelSemaphore)
 {
 	level++;
 
@@ -221,6 +255,12 @@ CopyEngine::_CollectCopyInfo(const char* _source, int32& level)
 
 	BEntry entry;
 	while (source.GetNextEntry(&entry) == B_OK) {
+		SemaphoreLocker lock(cancelSemaphore);
+		if (cancelSemaphore >= 0 && !lock.IsLocked()) {
+			// We are supposed to quit
+			return B_CANCELED;
+		}
+
 		struct stat statInfo;
 		entry.GetStat(&statInfo);
 
@@ -239,7 +279,10 @@ CopyEngine::_CollectCopyInfo(const char* _source, int32& level)
 			if (ret < B_OK)
 				return ret;
 
-			ret = _CollectCopyInfo(srcFolder.Path(), level);
+			if (cancelSemaphore >= 0)
+				lock.Unlock();
+
+			ret = _CollectCopyInfo(srcFolder.Path(), level, cancelSemaphore);
 			if (ret < B_OK)
 				return ret;
 		} else if (S_ISLNK(statInfo.st_mode)) {
@@ -259,7 +302,7 @@ CopyEngine::_CollectCopyInfo(const char* _source, int32& level)
 
 status_t
 CopyEngine::_CopyFolder(const char* _source, const char* _destination,
-	int32& level, BLocker* locker)
+	int32& level, sem_id cancelSemaphore)
 {
 	level++;
 	fCurrentTargetFolder = _destination;
@@ -283,8 +326,8 @@ CopyEngine::_CopyFolder(const char* _source, const char* _destination,
 
 	BEntry entry;
 	while (source.GetNextEntry(&entry) == B_OK) {
-		AutoLocker<BLocker> lock(locker);
-		if (locker != NULL && !lock.IsLocked()) {
+		SemaphoreLocker lock(cancelSemaphore);
+		if (cancelSemaphore >= 0 && !lock.IsLocked()) {
 			// We are supposed to quit
 			return B_CANCELED;
 		}
@@ -341,15 +384,15 @@ CopyEngine::_CopyFolder(const char* _source, const char* _destination,
 			if (ret < B_OK)
 				return ret;
 
-			if (locker != NULL)
+			if (cancelSemaphore >= 0)
 				lock.Unlock();
 
 			ret = _CopyFolder(srcFolder.Path(), dstFolder.Path(), level,
-				locker);
+				cancelSemaphore);
 			if (ret < B_OK)
 				return ret;
 
-			if (locker != NULL && !lock.Lock()) {
+			if (cancelSemaphore >= 0 && !lock.Lock()) {
 				// We are supposed to quit
 				return B_CANCELED;
 			}

src/apps/installer/CopyEngine.h

@@ -15,7 +15,6 @@
 #include "BlockingQueue.h"
 
 class BFile;
-class BLocker;
 class BMessage;
 class BMessenger;
 
@@ -26,23 +25,23 @@ public:
 	virtual						~CopyEngine();
 
 			void				ResetTargets();
-			status_t			CollectTargets(const char* source);
+			status_t			CollectTargets(const char* source,
+									sem_id cancelSemaphore = -1);
 
 			status_t			CopyFolder(const char* source,
 									const char* destination,
-									BLocker* locker = NULL);
+									sem_id cancelSemaphore = -1);
 
 			status_t			CopyFile(const BEntry& entry,
 									const BEntry& destination,
-									BLocker* locker = NULL);
+									sem_id cancelSemaphore = -1);
 
 private:
 			status_t			_CollectCopyInfo(const char* source,
-									int32& level);
+									int32& level, sem_id cancelSemaphore);
 			status_t			_CopyFolder(const char* source,
 									const char* destination,
-									int32& level,
-									BLocker* locker = NULL);
+									int32& level, sem_id cancelSemaphore);
 
 			bool				_ShouldCopyEntry(const char* name,
 									const struct stat& statInfo,

src/apps/installer/InstallerWindow.cpp

@@ -149,7 +149,7 @@ InstallerWindow::InstallerWindow()
 	fDriveSetupLaunched(false),
 	fInstallStatus(kReadyForInstall),
 	fWorkerThread(new WorkerThread(this)),
-	fCopyEngineLock(NULL)
+	fCopyEngineCancelSemaphore(-1)
 {
 	LogoView* logoView = new LogoView();
 
@@ -271,6 +271,7 @@ InstallerWindow::InstallerWindow()
 
 InstallerWindow::~InstallerWindow()
 {
+	_SetCopyEngineCancelSemaphore(-1);
 	be_roster->StopWatching(this);
 }
 
@@ -299,8 +300,7 @@ InstallerWindow::MessageReceived(BMessage *msg)
 	switch (msg->what) {
 		case MSG_RESET:
 		{
-			delete fCopyEngineLock;
-			fCopyEngineLock = NULL;
+			_SetCopyEngineCancelSemaphore(-1);
 
 			status_t error;
 			if (msg->FindInt32("error", &error) == B_OK) {
@@ -326,12 +326,13 @@ InstallerWindow::MessageReceived(BMessage *msg)
 			switch (fInstallStatus) {
 				case kReadyForInstall:
 				{
-					delete fCopyEngineLock;
-					fCopyEngineLock = new BLocker("copy engine lock");
+					_SetCopyEngineCancelSemaphore(create_sem(1,
+						"copy engine cancel"));
+
 					BList* list = new BList();
 					int32 size = 0;
 					fPackagesView->GetPackagesToInstall(list, &size);
-					fWorkerThread->SetLock(fCopyEngineLock);
+					fWorkerThread->SetLock(fCopyEngineCancelSemaphore);
 					fWorkerThread->SetPackagesList(list);
 					fWorkerThread->SetSpaceRequired(size);
 					fInstallStatus = kInstalling;
@@ -415,8 +416,8 @@ InstallerWindow::MessageReceived(BMessage *msg)
 		}
 		case MSG_INSTALL_FINISHED:
 		{
-			delete fCopyEngineLock;
-			fCopyEngineLock = NULL;
+			
+			_SetCopyEngineCancelSemaphore(-1);
 
 			fBeginButton->SetLabel("Quit");
 
@@ -688,14 +689,27 @@ InstallerWindow::_SetStatusMessage(const char *text)
 }
 
 
+void
+InstallerWindow::_SetCopyEngineCancelSemaphore(sem_id id, bool alreadyLocked)
+{
+	if (fCopyEngineCancelSemaphore >= 0) {
+		if (!alreadyLocked)
+			acquire_sem(fCopyEngineCancelSemaphore);
+		delete_sem(fCopyEngineCancelSemaphore);
+	}
+	fCopyEngineCancelSemaphore = id;
+}
+
+
 void
 InstallerWindow::_QuitCopyEngine(bool askUser)
 {
-	if (fCopyEngineLock == NULL)
+	if (fCopyEngineCancelSemaphore < 0)
 		return;
 
-	// first of all block the copy engine
-	fCopyEngineLock->Lock();
+	// First of all block the copy engine, so that it doesn't continue
+	// while the alert is showing, which would be irritating.
+	acquire_sem(fCopyEngineCancelSemaphore);
 	
 	bool quit = true;
 	if (askUser) {
@@ -706,23 +720,10 @@ InstallerWindow::_QuitCopyEngine(bool askUser)
 	}
 
 	if (quit) {
-		int32 tries = 0;
-		// wait until the engine blocks
-		while (fCopyEngineLock->CountLockRequests() < 2) {
-			// TODO: There is a race here, the copy engine
-			// may have finished before we locked the engine
-			// lock. That's why we limit the number of tries
-			// here.
-			tries++;
-			if (tries > 100)
-				break;
-			snooze(3000);
-		}
-		// make it quit by having it's lock fail
-		delete fCopyEngineLock;
-		fCopyEngineLock = NULL;
+		// Make it quit by having it's lock fail...
+		_SetCopyEngineCancelSemaphore(-1, true);
 	} else
-		fCopyEngineLock->Unlock();
+		release_sem(fCopyEngineCancelSemaphore);
 }
 
 

src/apps/installer/InstallerWindow.h

@@ -16,7 +16,6 @@ using namespace BPrivate;
 
 class BButton;
 class BLayoutItem;
-class BLocker;
 class BMenu;
 class BMenuField;
 class BStatusBar;
@@ -61,6 +60,8 @@ private:
 			void				_PublishPackages();
 			void				_SetStatusMessage(const char* text);
 
+			void				_SetCopyEngineCancelSemaphore(sem_id id,
+									bool alreadyLocked = false);
 			void				_QuitCopyEngine(bool askUser);
 
 	static	int					_ComparePackages(const void* firstArg,
@@ -95,7 +96,7 @@ private:
 
 			WorkerThread*		fWorkerThread;
 			BString				fLastStatus;
-			BLocker*			fCopyEngineLock;
+			sem_id				fCopyEngineCancelSemaphore;
 };
 
 #endif // INSTALLER_WINDOW_H

src/apps/installer/WorkerThread.cpp

@@ -77,7 +77,8 @@ WorkerThread::WorkerThread(InstallerWindow *window)
 	: BLooper("copy_engine"),
 	fWindow(window),
 	fPackages(NULL),
-	fSpaceRequired(0)
+	fSpaceRequired(0),
+	fCancelSemaphore(-1)
 {
 	Run();
 }
@@ -398,7 +399,7 @@ WorkerThread::_PerformInstall(BMenu* srcMenu, BMenu* targetMenu)
 
 	// let the engine collect information for the progress bar later on
 	engine.ResetTargets();
-	err = engine.CollectTargets(srcDirectory.Path());
+	err = engine.CollectTargets(srcDirectory.Path(), fCancelSemaphore);
 	if (err != B_OK)
 		goto error;
 
@@ -409,7 +410,7 @@ WorkerThread::_PerformInstall(BMenu* srcMenu, BMenu* targetMenu)
 		for (int32 i = 0; i < count; i++) {
 			Package *p = static_cast<Package*>(fPackages->ItemAt(i));
 			BPath packageDir(pkgRootDir.Path(), p->Folder());
-			err = engine.CollectTargets(packageDir.Path());
+			err = engine.CollectTargets(packageDir.Path(), fCancelSemaphore);
 			if (err != B_OK)
 				goto error;
 		}
@@ -417,7 +418,7 @@ WorkerThread::_PerformInstall(BMenu* srcMenu, BMenu* targetMenu)
 
 	// copy source volume
 	err = engine.CopyFolder(srcDirectory.Path(), targetDirectory.Path(),
-		fCancelLock);
+		fCancelSemaphore);
 	if (err != B_OK)
 		goto error;
 
@@ -429,7 +430,7 @@ WorkerThread::_PerformInstall(BMenu* srcMenu, BMenu* targetMenu)
 			Package *p = static_cast<Package*>(fPackages->ItemAt(i));
 			BPath packageDir(pkgRootDir.Path(), p->Folder());
 			err = engine.CopyFolder(packageDir.Path(), targetDirectory.Path(),
-				fCancelLock);
+				fCancelSemaphore);
 			if (err != B_OK)
 				goto error;
 		}

src/apps/installer/WorkerThread.h

@@ -14,7 +14,6 @@
 #include <Volume.h>
 
 class BList;
-class BLocker;
 class BMenu;
 class InstallerWindow;
 
@@ -32,8 +31,8 @@ public:
 									{ fSpaceRequired = bytes; };
 
 			bool				Cancel();
-			void				SetLock(BLocker* lock)
-									{ fCancelLock = lock; }
+			void				SetLock(sem_id cancelSemaphore)
+									{ fCancelSemaphore = cancelSemaphore; }
 
 			void				StartInstall();
 			void				WriteBootSector(BMenu* dstMenu);
@@ -50,7 +49,7 @@ private:
 			BDiskDeviceRoster	fDDRoster;
 			BList*				fPackages;
 			off_t				fSpaceRequired;
-			BLocker*			fCancelLock;
+			sem_id				fCancelSemaphore;
 };
 
 #endif // WORKER_THREAD_H