The singleton is a design pattern to ensure that exactly one application-wide instance of a particular class exists.
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121 views
Singleton-ish RMI Server
In this program there is a single remote server which performs miscellaneous work. Because there is only one server, it seems like a singleton pattern could fit well.
The problem that a distributed ...
6
votes
1answer
50 views
Creating an in-memory ViewCounter that commits to database every 10 minutes
This singleton is responsible for counting every pageview (called Routes in our case) we get by id, until the timer runs out and commits the results to the database in one query. Then the counter gets ...
2
votes
1answer
67 views
Global.asax singleton
Please help me decide whether this should be good or bad idea to declare a Singleton variable in Global.asax file. (It is not actually singleton pattern, I just want to make sure that only one ...
3
votes
1answer
77 views
Singleton base class
I just wrote a singleton base class for a hobby project I'm currently working on. Python is not my first language, which is why I am not sure if everything is done the pythonic way.
I also used ...
3
votes
2answers
77 views
Manage Sessions within a Singleton
I am looking for advice if the below code is a good idea or not. If not, why? I am building a website which allows a user to purchase items. The user account and cart items will be stored in Session. ...
2
votes
1answer
32 views
Javascript singleton to notify different objects of changes in viewport size
I'm working on a singleton object to manage size changes in the viewport, I wanted it to be a singleton because there may be different unrelated objects that need to be notified when a change in ...
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vote
0answers
35 views
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2answers
158 views
Building in the built-in declarations
In order for Rubberduck to be able to "recognize" the built-in VBA functions, procedures and objects, I added yet another constructor parameter to my Declaration ...
1
vote
1answer
104 views
Dependency injection thread safety
Is it OK to mix different lifetime of ISerializer and ICacheProvider in this case? I am using Unity DI. In this case, whenever ...
0
votes
1answer
85 views
0
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1answer
256 views
A Singleton Base and derived class
I have a base and derived class since I need to have different kinds of concrete classes.
I cannot use the getInstance() function in the base class since I cannot ...
3
votes
1answer
91 views
Reducing lock contention for a caching utility, or make it totally lockless but threadsafe
My Java program is a module called configProxy which fetches configuration entries from a remote node (say from a Redis instance). When the caller calls the ...
22
votes
4answers
13k views
Swift 1.2 Singleton Implementation
I am pretty new to Swift, as a solo developer I was wondering if somebody could pass comments on the singleton implementation below. The code does work, but being new to Swift and knowing that there ...
4
votes
1answer
127 views
Correct usage for singleton and reusability?
I've made the following DataSetReader, DS Attribute, and DataSetManager.
My main concerns ...
5
votes
3answers
290 views
Design of a remoteControl class for connecting to electronic devices
In a course that I'm taking on learning object oriented programming in java, I have completed an assignment for modeling a home entertainment system and the ability for a user to be able to use a ...
0
votes
1answer
141 views
PHP framework building: initializer and object loader classes
I am building a PHP framework and would like to get some feedback on a few different sections of the project. I consider myself still a neophyte in PHP so I would like to ask if I'm going about ...
1
vote
1answer
39 views
Managing a collection of object instances and getting them back out with instance manager / service locator
I'm creating an event loop for an asynchronous event execution library for PHP in PHP. Note that this is for a library and not an application. My event loop is just that -- a simple event loop that ...
3
votes
1answer
82 views
Execute startup method asynchronously
The goal is to call startManager on application start so that the manager is initialized in background without blocking application main thread.
Is it a safe ...
12
votes
1answer
120 views
Storing messages for the application's runtime
I am currently writing a well.. manual testing site for a chat-based bot. The full code can be found on github.
For that purpose I had to keep track of the messages currently in the "system". The ...
3
votes
0answers
142 views
Blocking builder with singleton
I am trying to implement a singleton builder that would be shared across
multiple builder threads for Coordinate objects.
Here is the simplified target class ...
3
votes
1answer
164 views
Ensure only a single instance of static template class member
I am interacting with a C library, whose documentation states that certain functions are not thread safe. Since its functions deal heterogeneously with multiple types, I have written a template ...
1
vote
0answers
79 views
Singleton request validator and sanitizor class
I have tried to code a PHP singleton class for validating multiple/single fields (sanitizing is optional). When validating single field, on success it will return 1 (...
5
votes
2answers
320 views
Thread-safe Phoenix Singleton class template with Boost
I've implemented the phoenix-singleton as a class template with boost inspired by Modern C++ Design. The code compiles fine with MSVC 2013 - and it seems to work, but I'm new
to multi-threaded ...
8
votes
1answer
1k views
Can we now `implement Singleton` using Java 8?
After my success with extending enum - I thought I would try to make Singleton creation as simple as possible since Java-8 makes ...
1
vote
2answers
343 views
Proper way to wait end of a service and singleton design
My code works fine and I would like to know if I chose the best strategy to implement my code, or if It can written better (more fast, more clear, best use of design pattern, etc).
In my android ...
2
votes
1answer
117 views
Lazy singleton with BackboneJS
I am trying to have a Backbone.Model which is a singleton and I wish to instantiate it lazily. I only need to support modern browsers so please do not worry about the use of ES5 getter.
Is this the ...
10
votes
5answers
4k views
Singleton Database class
Currently my team is building an application involving a database. We have to write a lot of data (approx 2,000,000 records) to the database and therefore we decided to open a connection once and ...
8
votes
3answers
519 views
Singleton Database wrapper
Before everybody yells at me about why I wrote a PDO wrapper class, it's to avoid writing try/catch, ...
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votes
2answers
875 views
Correct way to implement a Singleton field
I have a helper class that does HTTP operations on Android. Every method uses a client field. I think it's a good idea to make this client a singleton since every method in the class uses it.
The ...
4
votes
2answers
991 views
Singleton necessary in DAO
I am using a singleton in my DAO. Would I be better with static methods? Also, should I be worried about synchronization of the singleton and my data statures?
...
4
votes
2answers
139 views
Address book with singletons
My main goal with this refactor was to change instance methods that should have been class methods in the first place into class methods. My secondary goal was to add singletons to these classes ...
4
votes
2answers
81 views
Static variable representing program state accessed with multiple functions
I have this method that performs certain functions based on the state that the algorithm is currently at:
...
2
votes
2answers
731 views
PHP Trait Singleton
An implementation of the singleton pattern in PHP using a trait (added in 5.4). Is there anything missing, any ways to create a second copy of the class?
...
6
votes
1answer
883 views
Searching for songs on an Android application
In my application I need to search for some songs on my external storage card every now and then. On startup I read everything, however when it comes to new activities I thought I could just pass the ...
5
votes
2answers
414 views
Android global data
I have a huge list of song objects in my program and I need those objects in almost all activities. Well, at least a part of it up to everything.
So I created a class which looks pretty much like ...
5
votes
3answers
266 views
Is this good design for custom email template?
I read effective Java by Joshua Bloch. And it said use enums over int constant. So I was thinking instead of using hard coded strings I could also use enums. The forgotpassword.txt and ...
6
votes
1answer
96 views
Manage a collection of settings in memory with global scope
I have a WPF app and a bunch of read/write settings that need to be accessible from various view models. a setting can be any type (string, ...
1
vote
1answer
105 views
Singleton-like pattern for a project [closed]
I'm changing the inner implementation of a project. In order to do so, I've created an interface that will be implemented in 2 different ways.
One of this ways is by class ...
6
votes
4answers
2k views
Sound manager for Android
I created a singleton class for managing sound effects on Android. This class will only be instanced and loaded once at the beginning, and each activity will use the loaded songs.
I don't know either ...
3
votes
1answer
221 views
Singleton With Sub-Singletons
I've found myself wanting an easy way to implement chat into various apps, so I developed a set of classes for the firebase.com backend that make it easy for me to quickly set up the nuts and bolts of ...
6
votes
2answers
398 views
Singleton design pattern
I am a beginner in PHP-OOP and design patterns. I have got this basic piece of code in Singleton Pattern and I changed it in order to understand its behavior. I can see that it works as expected.
...
6
votes
1answer
238 views
A parametrized Config singleton
Here is an attempt to code a specific kind of Singleton - the one geared for our configuration needs. It needs to be initialized with a configuration location, do not allow copies or other instances, ...
4
votes
1answer
852 views
ResourceManager Singleton
As I understand creating lots of resource managers in C# may be a bad idea so I thought that the best thing to do would be to create a singleton for this.
However, I'm not 100% if this is a good ...
6
votes
2answers
750 views
Simple Java Singleton
Below is a Singleton that I designed as a piece of sample code for a website I'm working on for fun. The goal is to use the Singleton to hold an Earth object since ...
3
votes
2answers
2k views
Using a singleton class to get and set program wide settings
The following code works and does what I want, but I'd like to confirm I'm using this OOP concept correctly. I'm using the following class to get and set some configuration parameters for my program. ...
3
votes
1answer
93 views
How do I avoid explicit type switching when operation based on state?
I've encountered a problem that I have to solve using dynamic_cast to invoke different functions, depending on the type of class State family.
I was re-factoring a ...
0
votes
1answer
2k views
PHP starting OOP MySQLi singleton
this is my first post on the whole StackExchange network, so I might make some mistakes. And I'm also spanish spearker, so I'll probably have mistakes in my writting too..
Context: I'm starting with ...
6
votes
4answers
479 views
Singleton SpinLock: Making Random Thread-Safe
Is this a valid and safe use of .NET's System.Threading.SpinLock?
Why am I doing this?
Random's public methods are not ...
0
votes
1answer
149 views
Creating a singleton container class for intrer-class messaging
My question is for validation of my code (any loop holes / bugs) and guidance the best methodology to implement for my requirement.
I am developing a Python application that will have many classes. ...
2
votes
2answers
638 views
I need code review on using singleton to access local database
As I get to some performance issues in my app and find that I use database access in a bad way.
So I decided to move to singleton pattern.
I need someone to review this code and confirm me that I made ...
