jellyfin/MediaBrowser.Common/Extensions/ProcessExtensions.cs
2020-04-03 20:51:30 -04:00

80 lines
3.2 KiB
C#

using System;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;
namespace MediaBrowser.Common.Extensions
{
/// <summary>
/// Extension methods for <see cref="Process"/>.
/// </summary>
public static class ProcessExtensions
{
/// <summary>
/// Asynchronously wait for the process to exit.
/// </summary>
/// <param name="process">The process to wait for.</param>
/// <param name="timeout">The duration to wait before cancelling waiting for the task.</param>
/// <returns>True if the task exited normally, false if the timeout elapsed before the process exited.</returns>
public static async Task<bool> WaitForExitAsync(this Process process, TimeSpan timeout)
{
using (var cancelTokenSource = new CancellationTokenSource(timeout))
{
return await WaitForExitAsync(process, cancelTokenSource.Token).ConfigureAwait(false);
}
}
/// <summary>
/// Asynchronously wait for the process to exit.
/// </summary>
/// <param name="process">The process to wait for.</param>
/// <param name="cancelToken">A <see cref="CancellationToken"/> to observe while waiting for the process to exit.</param>
/// <returns>True if the task exited normally, false if cancelled before the process exited.</returns>
public static async Task<bool> WaitForExitAsync(this Process process, CancellationToken cancelToken)
{
if (!process.EnableRaisingEvents)
{
throw new InvalidOperationException("EnableRisingEvents must be enabled to async wait for a task to exit.");
}
// Add an event handler for the process exit event
var tcs = new TaskCompletionSource<bool>();
process.Exited += (sender, args) => tcs.TrySetResult(true);
// Return immediately if the process has already exited
if (process.HasExitedSafe())
{
return true;
}
// Register with the cancellation token then await
using (var cancelRegistration = cancelToken.Register(() => tcs.TrySetResult(process.HasExitedSafe())))
{
return await tcs.Task.ConfigureAwait(false);
}
}
/// <summary>
/// Gets a value indicating whether the associated process has been terminated using
/// <see cref="Process.HasExited"/>. This is safe to call even if there is no operating system process
/// associated with the <see cref="Process"/>.
/// </summary>
/// <param name="process">The process to check the exit status for.</param>
/// <returns>
/// True if the operating system process referenced by the <see cref="Process"/> component has
/// terminated, or if there is no associated operating system process; otherwise, false.
/// </returns>
private static bool HasExitedSafe(this Process process)
{
try
{
return process.HasExited;
}
catch (InvalidOperationException)
{
return true;
}
}
}
}