Async tweaks

MetaBrainz.MusicBrainz/Interfaces/IPagedQueryResults.cs

@@ -58,7 +58,7 @@ public interface IPagedQueryResults<TResults, out TItem> : IJsonBasedObject
  /// <returns>This result set (with updated values).</returns>
  /// <exception cref="QueryException">When the web service reports an error.</exception>
  /// <exception cref="WebException">When something goes wrong with the web request.</exception>
- Task<TResults> NextAsync(CancellationToken cancellationToken = new());
+ Task<TResults> NextAsync(CancellationToken cancellationToken = default);
 
  /// <summary>
  /// The offset to use for the next request (via <see cref="Next()"/> and/or <see cref="Previous()"/>), or <see langword="null"/>
@@ -89,7 +89,7 @@ public interface IPagedQueryResults<TResults, out TItem> : IJsonBasedObject
  /// <returns>This result set (with updated values).</returns>
  /// <exception cref="QueryException">When the web service reports an error.</exception>
  /// <exception cref="WebException">When something goes wrong with the web request.</exception>
- Task<TResults> PreviousAsync(CancellationToken cancellationToken = new());
+ Task<TResults> PreviousAsync(CancellationToken cancellationToken = default);
 
  /// <summary>The current results.</summary>
  IReadOnlyList<TItem> Results { get; }

MetaBrainz.MusicBrainz/OAuth2.cs

@@ -219,7 +219,7 @@ public IAuthorizationToken GetBearerToken(string code, string clientSecret, Uri
  /// <param name="cancellationToken">The cancellation token to cancel the operation.</param>
  /// <returns>The obtained bearer token.</returns>
  public Task<IAuthorizationToken> GetBearerTokenAsync(string code, string clientSecret, Uri redirectUri,
- CancellationToken cancellationToken = new())
+ CancellationToken cancellationToken = default)
  => this.RequestTokenAsync("bearer", code, clientSecret, redirectUri, cancellationToken);
 
  /// <summary>Refreshes a bearer token.</summary>
@@ -235,7 +235,7 @@ public IAuthorizationToken RefreshBearerToken(string refreshToken, string client
  /// <param name="cancellationToken">The cancellation token to cancel the operation.</param>
  /// <returns>The obtained bearer token.</returns>
  public Task<IAuthorizationToken> RefreshBearerTokenAsync(string refreshToken, string clientSecret,
- CancellationToken cancellationToken = new())
+ CancellationToken cancellationToken = default)
  => this.RefreshTokenAsync("bearer", refreshToken, clientSecret, cancellationToken);
 
  #endregion
@@ -256,8 +256,6 @@ public Task<IAuthorizationToken> RefreshBearerTokenAsync(string refreshToken, st
 
  private Func<HttpClient>? _clientCreation;
 
- private readonly SemaphoreSlim _clientLock = new(1);
-
  private readonly bool _clientOwned;
 
  private bool _disposed;
@@ -285,14 +283,7 @@ public void Close() {
  if (!this._clientOwned) {
  throw new InvalidOperationException("An explicitly provided client instance is in use.");
  }
- this._clientLock.Wait();
- try {
- this._client?.Dispose();
- this._client = null;
- }
- finally {
- this._clientLock.Release();
- }
+ Interlocked.Exchange(ref this._client, null)?.Dispose();
  }
 
  /// <summary>Sets up code to run to configure a newly-created HTTP client.</summary>
@@ -328,7 +319,6 @@ private void Dispose(bool disposing) {
  this.Close();
  }
  this._client = null;
- this._clientLock.Dispose();
  }
  finally {
  this._disposed = true;
@@ -348,52 +338,48 @@ private void Dispose(bool disposing) {
  private async Task<HttpResponseMessage> PerformRequestAsync(Uri uri, HttpMethod method, HttpContent? body,
  CancellationToken cancellationToken) {
  Debug.Print($"[{DateTime.UtcNow}] WEB SERVICE REQUEST: {method.Method} {uri}");
- await this._clientLock.WaitAsync(cancellationToken);
- try {
- var client = this.Client;
- using var request = new HttpRequestMessage(method, uri) {
- Content = body,
- Headers = {
- Accept = {
- OAuth2.AcceptHeader,
- },
- }
- };
- // Use whatever user agent the client has set, plus our own.
- foreach (var userAgent in client.DefaultRequestHeaders.UserAgent) {
- request.Headers.UserAgent.Add(userAgent);
+ var client = this.Client;
+ using var request = new HttpRequestMessage(method, uri) {
+ Content = body,
+ Headers = {
+ Accept = {
+ OAuth2.AcceptHeader,
+ },
  }
- request.Headers.UserAgent.Add(OAuth2.LibraryProductInfo);
- request.Headers.UserAgent.Add(OAuth2.LibraryComment);
- Debug.Print($"[{DateTime.UtcNow}] => HEADERS: {Utils.FormatMultiLine(request.Headers.ToString())}");
- if (body is not null) {
- // FIXME: Should this include the actual body text too?
- Debug.Print($"[{DateTime.UtcNow}] => BODY ({body.Headers.ContentType}): {body.Headers.ContentLength ?? 0} bytes");
- }
- var response = await client.SendAsync(request, cancellationToken);
- Debug.Print($"[{DateTime.UtcNow}] WEB SERVICE RESPONSE: {(int) response.StatusCode}/{response.StatusCode} " +
- $"'{response.ReasonPhrase}' (v{response.Version})");
- Debug.Print($"[{DateTime.UtcNow}] => HEADERS: {Utils.FormatMultiLine(response.Headers.ToString())}");
- Debug.Print($"[{DateTime.UtcNow}] => CONTENT ({response.Content.Headers.ContentType}): " +
- $"{response.Content.Headers.ContentLength ?? 0} bytes");
- return response;
+ };
+ // Use whatever user agent the client has set, plus our own.
+ foreach (var userAgent in client.DefaultRequestHeaders.UserAgent) {
+ request.Headers.UserAgent.Add(userAgent);
  }
- finally {
- this._clientLock.Release();
+ request.Headers.UserAgent.Add(OAuth2.LibraryProductInfo);
+ request.Headers.UserAgent.Add(OAuth2.LibraryComment);
+ Debug.Print($"[{DateTime.UtcNow}] => HEADERS: {Utils.FormatMultiLine(request.Headers.ToString())}");
+ if (body is not null) {
+ // FIXME: Should this include the actual body text too?
+ Debug.Print($"[{DateTime.UtcNow}] => BODY ({body.Headers.ContentType}): {body.Headers.ContentLength ?? 0} bytes");
  }
+ var response = await client.SendAsync(request, cancellationToken).ConfigureAwait(false);
+ Debug.Print($"[{DateTime.UtcNow}] WEB SERVICE RESPONSE: {(int) response.StatusCode}/{response.StatusCode} " +
+ $"'{response.ReasonPhrase}' (v{response.Version})");
+ Debug.Print($"[{DateTime.UtcNow}] => HEADERS: {Utils.FormatMultiLine(response.Headers.ToString())}");
+ Debug.Print($"[{DateTime.UtcNow}] => CONTENT ({response.Content.Headers.ContentType}): " +
+ $"{response.Content.Headers.ContentLength ?? 0} bytes");
+ return response;
  }
 
- private async Task<AuthorizationToken> PostAsync(HttpContent body, CancellationToken cancellationToken) {
+ private async Task<AuthorizationToken> PostAsync(HttpContent content, CancellationToken cancellationToken) {
  var uri = new UriBuilder(this.UrlScheme, this.Server, this.Port, OAuth2.TokenEndPoint).Uri;
- var response = await this.PerformRequestAsync(uri, HttpMethod.Post, body, cancellationToken);
+ var response = await this.PerformRequestAsync(uri, HttpMethod.Post, content, cancellationToken).ConfigureAwait(false);
  if (!response.IsSuccessStatusCode) {
- throw await Utils.CreateQueryExceptionForAsync(response, cancellationToken);
+ throw await Utils.CreateQueryExceptionForAsync(response, cancellationToken).ConfigureAwait(false);
  }
- return await Utils.GetJsonContentAsync<AuthorizationToken>(response, OAuth2.JsonReaderOptions, cancellationToken);
+ var jsonTask = Utils.GetJsonContentAsync<AuthorizationToken>(response, OAuth2.JsonReaderOptions, cancellationToken);
+ return await jsonTask.ConfigureAwait(false);
  }
 
  private async Task<IAuthorizationToken> PostAsync(string type, string body, CancellationToken cancellationToken) {
- var token = await this.PostAsync(new StringContent(body, Encoding.UTF8, OAuth2.TokenRequestBodyType), cancellationToken);
+ var content = new StringContent(body, Encoding.UTF8, OAuth2.TokenRequestBodyType);
+ var token = await this.PostAsync(content, cancellationToken).ConfigureAwait(false);
  if (token.TokenType != type) {
  throw new InvalidOperationException($"Token request returned a token of the wrong type ('{token.TokenType}' != '{type}').");
  }
@@ -408,7 +394,7 @@ private async Task<IAuthorizationToken> RefreshTokenAsync(string type, string co
  body.Append("&token_type=").Append(Uri.EscapeDataString(type));
  body.Append("&grant_type=refresh_token");
  body.Append("&refresh_token=").Append(Uri.EscapeDataString(codeOrToken));
- return await this.PostAsync(type, body.ToString(), cancellationToken);
+ return await this.PostAsync(type, body.ToString(), cancellationToken).ConfigureAwait(false);
  }
 
  private async Task<IAuthorizationToken> RequestTokenAsync(string type, string codeOrToken, string clientSecret, Uri redirectUri,
@@ -420,7 +406,7 @@ private async Task<IAuthorizationToken> RequestTokenAsync(string type, string co
  body.Append("&grant_type=authorization_code");
  body.Append("&code=").Append(Uri.EscapeDataString(codeOrToken));
  body.Append("&redirect_uri=").Append(Uri.EscapeDataString(redirectUri.ToString()));
- return await this.PostAsync(type, body.ToString(), cancellationToken);
+ return await this.PostAsync(type, body.ToString(), cancellationToken).ConfigureAwait(false);
  }
 
  private static IEnumerable<string> ScopeStrings(AuthorizationScope scope) {

MetaBrainz.MusicBrainz/Objects/Browses/BrowseResults.cs

@@ -22,7 +22,8 @@ protected BrowseResults(Query query, string endpoint, string? value, string extr
 
  protected sealed override async Task<IBrowseResults<TResult>> DeserializeAsync(HttpResponseMessage response,
  CancellationToken cancellationToken) {
- this.CurrentResult = await Utils.GetJsonContentAsync<BrowseResult>(response, Query.JsonReaderOptions, cancellationToken);
+ var task = Utils.GetJsonContentAsync<BrowseResult>(response, Query.JsonReaderOptions, cancellationToken);
+ this.CurrentResult = await task.ConfigureAwait(false);
  return this;
  }
 

MetaBrainz.MusicBrainz/Objects/PagedQueryResults.cs

@@ -33,7 +33,7 @@ protected PagedQueryResults(Query query, string endpoint, string? value, int? li
 
  public TResults Next() => Utils.ResultOf(this.NextAsync());
 
- public async Task<TResults> NextAsync(CancellationToken cancellationToken = new()) {
+ public async Task<TResults> NextAsync(CancellationToken cancellationToken = default) {
  this.UpdateOffset(this.Results.Count);
  return await this.PerformRequestAsync(cancellationToken).ConfigureAwait(false);
  }
@@ -44,7 +44,7 @@ protected PagedQueryResults(Query query, string endpoint, string? value, int? li
 
  public TResults Previous() => Utils.ResultOf(this.PreviousAsync());
 
- public async Task<TResults> PreviousAsync(CancellationToken cancellationToken = new()) {
+ public async Task<TResults> PreviousAsync(CancellationToken cancellationToken = default) {
  this.UpdateOffset();
  return await this.PerformRequestAsync(cancellationToken).ConfigureAwait(false);
  }

MetaBrainz.MusicBrainz/Objects/Searches/SearchResults.cs

@@ -75,7 +75,8 @@ protected SearchResults(Query query, string endpoint, string queryString, int? l
 
  protected sealed override async Task<ISearchResults<TInterface>> DeserializeAsync(HttpResponseMessage response,
  CancellationToken cancellationToken) {
- this.CurrentResult = await Utils.GetJsonContentAsync<SearchResults>(response, Query.JsonReaderOptions, cancellationToken);
+ var task = Utils.GetJsonContentAsync<SearchResults>(response, Query.JsonReaderOptions, cancellationToken);
+ this.CurrentResult = await task.ConfigureAwait(false);
  if (this.Offset != this.CurrentResult.Offset) {
  Debug.Print($"Unexpected offset in search results: {this.Offset} != {this.CurrentResult.Offset}.");
  }

MetaBrainz.MusicBrainz/Objects/StreamingQueryResults.cs

@@ -18,10 +18,10 @@ public StreamingQueryResults(PagedQueryResults<TResult, TItem, TResultObject> pa
 
  #region IAsyncEnumerable
 
- public async IAsyncEnumerator<TItem> GetAsyncEnumerator(CancellationToken cancellationToken = new()) {
+ public async IAsyncEnumerator<TItem> GetAsyncEnumerator(CancellationToken cancellationToken = default) {
  IPagedQueryResults<TResult, TItem> currentPage = this._pagedResults;
  if (!currentPage.IsActive) {
- currentPage = await currentPage.NextAsync(cancellationToken);
+ currentPage = await currentPage.NextAsync(cancellationToken).ConfigureAwait(false);
  if (cancellationToken.IsCancellationRequested) {
  yield break;
  }
@@ -36,7 +36,7 @@ public StreamingQueryResults(PagedQueryResults<TResult, TItem, TResultObject> pa
  if (currentPage.Offset + currentPage.Results.Count >= currentPage.TotalResults || cancellationToken.IsCancellationRequested) {
  break;
  }
- currentPage = await currentPage.NextAsync(cancellationToken);
+ currentPage = await currentPage.NextAsync(cancellationToken).ConfigureAwait(false);
  }
  }
 

MetaBrainz.MusicBrainz/Objects/Submissions/Submission.cs

@@ -28,7 +28,7 @@ public abstract class Submission : ISubmission {
  /// <returns>A message describing the result (usually "OK").</returns>
  /// <exception cref="QueryException">When the MusicBrainz web service reports an error.</exception>
  /// <exception cref="System.Net.WebException">When the MusicBrainz web service could not be contacted.</exception>
- public async Task<string> SubmitAsync(CancellationToken cancellationToken = new())
+ public async Task<string> SubmitAsync(CancellationToken cancellationToken = default)
  => await this._query.PerformSubmissionAsync(this, cancellationToken).ConfigureAwait(false);
 
  #endregion

MetaBrainz.MusicBrainz/Query.Browse.Areas.cs

@@ -68,7 +68,7 @@ public IBrowseResults<IArea> BrowseAreas(ICollection collection, int? limit = nu
  /// <exception cref="QueryException">When the web service reports an error.</exception>
  /// <exception cref="WebException">When something goes wrong with the web request.</exception>
  public Task<IBrowseResults<IArea>> BrowseAreasAsync(ICollection collection, int? limit = null, int? offset = null,
- Include inc = Include.None, CancellationToken cancellationToken = new())
+ Include inc = Include.None, CancellationToken cancellationToken = default)
  => new BrowseAreas(this, Query.BuildExtraText(inc, "collection", collection.Id), limit, offset).NextAsync(cancellationToken);
 
  /// <summary>Returns (the specified subset of) the areas in the given collection.</summary>
@@ -93,7 +93,7 @@ public IBrowseResults<IArea> BrowseCollectionAreas(Guid mbid, int? limit = null,
  /// <exception cref="WebException">When something goes wrong with the web request.</exception>
  public Task<IBrowseResults<IArea>> BrowseCollectionAreasAsync(Guid mbid, int? limit = null, int? offset = null,
  Include inc = Include.None,
- CancellationToken cancellationToken = new())
+ CancellationToken cancellationToken = default)
  => new BrowseAreas(this, Query.BuildExtraText(inc, "collection", mbid), limit, offset).NextAsync(cancellationToken);
 
 }