ktsu.SingleAppInstance 1.2.3

Prefix Reserved
.NET 8.0 This package targets .NET 8.0. The package is compatible with this framework or higher.
There is a newer version of this package available.
See the version list below for details. 
dotnet add package ktsu.SingleAppInstance --version 1.2.3
                    


                    

                
NuGet\Install-Package ktsu.SingleAppInstance -Version 1.2.3
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="ktsu.SingleAppInstance" Version="1.2.3" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="ktsu.SingleAppInstance" Version="1.2.3" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="ktsu.SingleAppInstance" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add ktsu.SingleAppInstance --version 1.2.3
                    


                    

                
#r "nuget: ktsu.SingleAppInstance, 1.2.3"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
#addin nuget:?package=ktsu.SingleAppInstance&version=1.2.3
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=ktsu.SingleAppInstance&version=1.2.3
                    


                            Install as a Cake Tool

ktsu.SingleAppInstance

Overview

The SingleAppInstance class provides a mechanism to ensure that only one instance of an application is running at a time. This is useful for applications that should not have multiple instances running simultaneously, such as desktop applications or services.

Features

  • Single Instance Enforcement: Ensures that only one instance of the application is running.
  • Enhanced Process Identification: Uses detailed process information (PID, process name, start time, main module filename) to accurately identify running instances.
  • PID File Management: Stores process information in JSON format in the application data directory.
  • Race Condition Handling: Handles potential race conditions when starting multiple instances simultaneously with a timeout mechanism.
  • Backward Compatibility: Maintains compatibility with older versions that only stored the PID.

Installation

To install the ktsu.SingleAppInstance package, run the following command:

dotnet add package ktsu.SingleAppInstance

Usage

Basic Usage

To use the SingleAppInstance class, call the ExitIfAlreadyRunning method at the start of your application:

using ktsu.SingleAppInstance;

class Program
{
    static void Main(string[] args)
    {
        SingleAppInstance.ExitIfAlreadyRunning();
        
        // Your application code here
        Console.WriteLine("Application is running.");
    }
}

Custom Launch Logic

If you prefer to explicitly handle the case where another instance is already running:

using ktsu.SingleAppInstance;

class Program
{
    static void Main(string[] args)
    {
        if (SingleAppInstance.ShouldLaunch())
        {
            // Your application code here
            Console.WriteLine("Application is running.");
        }
        else
        {
            // Handle the case where another instance is already running
            Console.WriteLine("Another instance is already running.");
        }
    }
}

Methods

  • ExitIfAlreadyRunning(): Exits the application with a status code of 0 if another instance is already running.
  • ShouldLaunch(): Determines whether the application should launch based on whether another instance is running. It also handles writing the current process information to a PID file and implements a waiting mechanism to handle potential race conditions.

Technical Implementation

Under the hood, SingleAppInstance:

  1. Stores a JSON-serialized ProcessInfo object containing:

    • Process ID
    • Process name
    • Start time
    • Main module filename

  2. Uses the application data directory to store the PID file. The file is named .SingleAppInstance.pid.

  3. When checking for running instances, it:

    • Reads the PID file
    • Verifies if a process with the stored ID exists
    • Confirms it's the same application by comparing process name and executable path
    • Handles access restrictions and various edge cases

  4. Implements a 1-second timeout in ShouldLaunch() to detect race conditions when multiple instances start simultaneously.

Contributing

Contributions are welcome! Please open an issue or submit a pull request on GitHub.

Support

If you encounter any issues or have questions, please open an issue on GitHub.

License

This project is licensed under the MIT License.

Product Compatible and additional computed target framework versions.
.NET net8.0 is compatible.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed.  net9.0 is compatible.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed.  net10.0 was computed.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
1.2.6-pre.18 116 5/20/2025
1.2.6-pre.15 73 5/17/2025
1.2.6-pre.14 127 5/16/2025
1.2.6-pre.13 198 5/15/2025
1.2.6-pre.12 194 5/14/2025
1.2.6-pre.11 194 5/13/2025
1.2.6-pre.10 227 5/12/2025
1.2.6-pre.9 164 5/11/2025
1.2.6-pre.8 104 5/10/2025
1.2.6-pre.7 46 5/9/2025
1.2.6-pre.6 117 5/8/2025
1.2.6-pre.5 117 5/7/2025
1.2.6-pre.4 114 5/6/2025
1.2.6-pre.3 114 5/5/2025
1.2.6-pre.2 116 5/4/2025
1.2.6-pre.1 111 5/4/2025
1.2.5 145 5/4/2025
1.2.5-pre.3 107 4/29/2025
1.2.5-pre.2 128 4/28/2025
1.2.5-pre.1 62 4/26/2025
1.2.4 141 4/25/2025
1.2.3 111 4/19/2025
1.2.2 176 4/18/2025
1.2.2-pre.3 60 4/4/2025
1.2.2-pre.2 113 4/4/2025
1.2.2-pre.1 132 3/31/2025
1.2.1 147 3/30/2025
1.2.0 149 3/30/2025
1.1.1-pre.2 74 3/29/2025
1.1.1-pre.1 462 3/25/2025
1.1.0 119 2/17/2025
1.0.0-pre.19 71 2/14/2025
1.0.0-pre.18 72 2/6/2025
1.0.0-pre.17 68 2/5/2025
1.0.0-pre.16 61 2/5/2025
1.0.0-pre.15 69 2/3/2025
1.0.0-pre.14 70 2/3/2025
1.0.0-pre.13 62 2/3/2025
1.0.0-pre.12 79 2/2/2025
1.0.0-pre.11 65 1/31/2025
1.0.0-pre.10 63 1/30/2025
1.0.0-pre.9 75 1/28/2025
1.0.0-pre.8 64 1/26/2025
1.0.0-pre.7 58 1/24/2025
1.0.0-pre.6 65 1/22/2025
1.0.0-pre.5 65 1/20/2025
1.0.0-pre.4 57 1/18/2025
1.0.0-pre.3 58 1/16/2025
1.0.0-pre.2 43 1/14/2025
1.0.0-pre.1 65 1/13/2025
0.0.1-pre.1 58 1/13/2025

## v1.2.3 (patch)

Changes since v1.2.2:

- Add guidelines for using command line in non-interactive mode and directory context ([@matt-edmondson](https://github.com/matt-edmondson))
- Add memory.jsonl file with project and class details ([@matt-edmondson](https://github.com/matt-edmondson))
- Add SingleAppInstance.Test project to solution and configure build settings ([@matt-edmondson](https://github.com/matt-edmondson))
- Add tests for SingleAppInstance behavior with no other instance running and custom launch logic ([@matt-edmondson](https://github.com/matt-edmondson))
- Add workflow and process guidelines to Copilot instructions ([@matt-edmondson](https://github.com/matt-edmondson))
- Clarify command line usage by providing an example for non-interactive mode with `git` commands ([@matt-edmondson](https://github.com/matt-edmondson))
- Comment out MaxCpuCount setting in .runsettings to disable process-level parallelization ([@matt-edmondson](https://github.com/matt-edmondson))
- Enhance memory.jsonl to include additional details for SingleAppInstance tests and project structure ([@matt-edmondson](https://github.com/matt-edmondson))
- Enhance memory.jsonl to include advanced process detection and compatibility details for SingleAppInstance class ([@matt-edmondson](https://github.com/matt-edmondson))
- Enhance SingleAppInstance to store and verify process information in JSON format ([@matt-edmondson](https://github.com/matt-edmondson))
- Enhance SingleAppInstanceTests by adding assertions to verify PID file handling and initial state checks ([@matt-edmondson](https://github.com/matt-edmondson))
- Organize and enhance Copilot documentation with detailed guidelines on memory usage, coding standards, and project management practices. ([@matt-edmondson](https://github.com/matt-edmondson))
- Refactor SingleAppInstanceTests for better isolation ([@matt-edmondson](https://github.com/matt-edmondson))
- Refactor SingleAppInstanceTests to improve clarity and structure of test methods, ensuring accurate PID file handling and process information validation. ([@matt-edmondson](https://github.com/matt-edmondson))
- Refactor SingleAppInstanceTests to simplify file deletion logic and remove unnecessary try-finally blocks, ensuring clearer test flow and improved readability. ([@matt-edmondson](https://github.com/matt-edmondson))
- Refine README.md for clarity and usage instructions of SingleAppInstance ([@matt-edmondson](https://github.com/matt-edmondson))
- Refine README.md to enhance feature descriptions and clarify technical implementation details for SingleAppInstance ([@matt-edmondson](https://github.com/matt-edmondson))
- Refine workflow guidelines for clarity on specialized tool usage and documentation checks ([@matt-edmondson](https://github.com/matt-edmondson))
- Set max cpus for tests to 1 ([@matt-edmondson](https://github.com/matt-edmondson))
- Update Copilot instructions for .NET project build and testing guidelines ([@matt-edmondson](https://github.com/matt-edmondson))
- Update language-specific guidelines to clarify test execution commands and improve resource management ([@matt-edmondson](https://github.com/matt-edmondson))
- Update language-specific guidelines to clarify tool usage and fallback options ([@matt-edmondson](https://github.com/matt-edmondson))
- Update test command to run in a single process ([@matt-edmondson](https://github.com/matt-edmondson))

## v1.2.2 (patch)

Changes since v1.2.1:

- Add comprehensive Copilot instructions and memory management guidelines ([@matt-edmondson](https://github.com/matt-edmondson))
- Add markdownlint configuration file for linting rules ([@matt-edmondson](https://github.com/matt-edmondson))

## v1.2.1 (patch)

Changes since v1.2.0:

- Update packages ([@matt-edmondson](https://github.com/matt-edmondson))

## v1.2.0 (minor)

Changes since v1.1.0:

- Add LICENSE template ([@matt-edmondson](https://github.com/matt-edmondson))

## v1.1.0 (minor)

Changes since v1.0.0-pre.19:

- Apply new editorconfig ([@matt-edmondson](https://github.com/matt-edmondson))