app_server: FontStyle lifecycle

FontFamily is babysitted by the FontManager. It doesn't own FontStyle
references, there's no place in it to release them.

FontManager owns a reference to the FontStyle, and it is in
fStyleHashTable. Putting a style there acquires a new reference, so we
can release the one from the new style. Removing a style from the map
releases the reference. We need to clear the map before shutting down
FreeType to get rid of our last references and let the styles die now
instead of afterwards to avoid double freeing the faces.

These solve the new crash from the previous patch. It didn't crash
before because even after the map was destroyed there were still
dangling references to the styles.

On removing a user font, the style will remove itself from the family
through the manager if that was the last reference, and the manager will
remove and delete the family if it has no more styles.

Change-Id: I460ff830fa8a8a5adb90dc8ea12120e1e50a5912
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6052
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

src/servers/app/ServerApp.cpp

@@ -1766,12 +1766,7 @@ ServerApp::_DispatchMessage(int32 code, BPrivate::LinkReceiver& link)
 			status_t status = B_OK;
 
 			AutoLocker<FontManagerBase> fontLock(fAppFontManager);
-			FontStyle* style = fAppFontManager->GetStyle(familyID, styleID);
+			status = fAppFontManager->RemoveUserFont(familyID, styleID);
-
-			if (style != NULL) {
-				status = fAppFontManager->RemoveUserFont(familyID, styleID);
-			} else
-				status = B_BAD_VALUE;
 
 			fLink.StartMessage(status);
 			fLink.Flush();

src/servers/app/font/AppFontManager.cpp

@@ -95,6 +95,7 @@ AppFontManager::_AddUserFont(FT_Face face, node_ref nodeRef, const char* path,
 	styleID = style->ID();
 
 	fStyleHashTable.Put(FontKey(familyID, styleID), style);
+	style->ReleaseReference();
 
 	return B_OK;
 }
@@ -160,19 +161,7 @@ AppFontManager::RemoveUserFont(uint16 familyID, uint16 styleID)
 	ASSERT(IsLocked());
 
 	FontKey fKey(familyID, styleID);
-	FontStyle* styleRef = fStyleHashTable.Get(fKey);
+	FontStyle* styleRef = fStyleHashTable.Remove(fKey);
-	fStyleHashTable.Remove(fKey);
 
-	FontFamily* family = styleRef->Family();
+	return styleRef != NULL ? B_OK : B_BAD_VALUE;
-	bool removed = family->RemoveStyle(styleRef, this);
-
-	if (!removed)
-		syslog(LOG_DEBUG, "AppFontManager::RemoveUserFont style not removed from family\n");
-
-	fFamilies.RemoveItem(family);
-	delete family;
-
-	styleRef->ReleaseReference();
-
-	return B_OK;
 }

src/servers/app/font/FontFamily.cpp

@@ -78,8 +78,6 @@ FontFamily::~FontFamily()
 		// we remove us before deleting the style, so that the font manager
 		// is not contacted to remove the style from us
 		style->_SetFontFamily(NULL, -1);
-
-		style->ReleaseReference();
 	}
 }
 

src/servers/app/font/FontManager.cpp

@@ -69,6 +69,8 @@ FontManagerBase::~FontManagerBase()
 	for (int32 i = fFamilies.CountItems(); i-- > 0;)
 		delete fFamilies.ItemAt(i);
 
+	fStyleHashTable.Clear();
+
 	if (fHasFreetypeLibrary == true)
 		FT_Done_FreeType(gFreeTypeLibrary);
 }
@@ -306,8 +308,10 @@ FontManagerBase::RemoveStyle(FontStyle* style)
 		debugger("style removed but still available!");
 
 	if (family->RemoveStyle(style)
-		&& family->CountStyles() == 0)
+		&& family->CountStyles() == 0) {
 		fFamilies.RemoveItem(family);
+		delete family;
+	}
 }
 
 
@@ -320,4 +324,4 @@ FontManagerBase::_FindFamily(const char* name) const
 	FontFamily family(name, 0);
 	return const_cast<FontFamily*>(fFamilies.BinarySearch(family,
 		compare_font_families));
-}
+}

src/servers/app/font/GlobalFontManager.cpp

@@ -484,8 +484,6 @@ GlobalFontManager::_RemoveStyle(font_directory& directory, FontStyle* style)
 	directory.revision++;
 
 	fStyleHashTable.Remove(FontKey(style->Family()->ID(), style->ID()));
-
-	style->ReleaseReference();
 }
 
 
@@ -741,6 +739,7 @@ GlobalFontManager::_AddFont(font_directory& directory, BEntry& entry)
 
 	directory.styles.AddItem(style);
 	fStyleHashTable.Put(FontKey(style->Family()->ID(), style->ID()), style);
+	style->ReleaseReference();
 
 	if (directory.AlreadyScanned())
 		directory.revision++;