SemaphoreSlimContext.cs

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using System;
using System.Threading;
using System.Threading.Tasks;
 
using Microsoft.Extensions.Logging;
 
namespace Tgstation.Server.Host.Utils
{
    sealed class SemaphoreSlimContext : IDisposable
    {
        public static async ValueTask<SemaphoreSlimContext> Lock(SemaphoreSlim semaphore, CancellationToken cancellationToken, ILogger? logger = null)
        {
            ArgumentNullException.ThrowIfNull(semaphore);
            logger?.LogTrace("Acquiring semaphore...");
            await semaphore.WaitAsync(cancellationToken);
            return new SemaphoreSlimContext(semaphore, logger);
        }
 
        public static SemaphoreSlimContext? TryLock(SemaphoreSlim semaphore, ILogger? logger, out bool locked)
        {
            ArgumentNullException.ThrowIfNull(semaphore);
            logger?.LogTrace("Trying to acquire semaphore...");
            locked = semaphore.Wait(TimeSpan.Zero);
            logger?.LogTrace("Acquired semaphore {un}successfully", locked ? String.Empty : "un");
            return locked
                ? new SemaphoreSlimContext(semaphore, logger)
                : null;
        }
 
        readonly ILogger? logger;
 
        readonly SemaphoreSlim lockedSemaphore;
 
        SemaphoreSlimContext(SemaphoreSlim lockedSemaphore, ILogger? logger)
        {
            this.lockedSemaphore = lockedSemaphore;
            this.logger = logger;
        }
 
        public void Dispose()
        {
            logger?.LogTrace("Releasing semaphore...");
            lockedSemaphore.Release();
        }
    }
}