private static async Task <byte[]> ExecuteDevToolsMethodInternalAsync(IChromiumWebView webview, string method, CefDictionaryValue parameters, CancellationToken cancellationToken)
{
CefBrowser browser = webview.BrowserObject;
if (browser is null)
{
throw new InvalidOperationException();
}
cancellationToken.ThrowIfCancellationRequested();
CefBrowserHost browserHost = browser.Host;
DevToolsProtocolClient protocolClient = GetProtocolClient(browserHost);
await CefNetSynchronizationContextAwaiter.GetForThread(CefThreadId.UI);
cancellationToken.ThrowIfCancellationRequested();
int messageId = browserHost.ExecuteDevToolsMethod(protocolClient.IncrementMessageId(), method, parameters);
protocolClient.UpdateLastMessageId(messageId);
DevToolsMethodResult r;
if (cancellationToken.CanBeCanceled)
{
Task <DevToolsMethodResult> waitTask = protocolClient.WaitForMessageAsync(messageId);
await Task.WhenAny(waitTask, Task.Delay(Timeout.Infinite, cancellationToken)).ConfigureAwait(false);
cancellationToken.ThrowIfCancellationRequested();
r = waitTask.Result;
}
else
{
r = await protocolClient.WaitForMessageAsync(messageId).ConfigureAwait(false);
}
if (r.Success)
{
return(r.Result);
}
CefValue errorValue = CefApi.CefParseJSONBuffer(r.Result, CefJsonParserOptions.AllowTrailingCommas);
if (errorValue is null)
{
throw new DevToolsProtocolException($"An unknown error occurred while trying to execute the '{method}' method.");
}
throw new DevToolsProtocolException(errorValue.GetDictionary().GetString("message"));
}
/// <summary>
/// Returns the <see cref="CefNetSynchronizationContextAwaiter"/> for the specified CEF thread.
/// </summary>
/// <param name="threadId">The CEF thread identifier.</param>
/// <returns>The <see cref="CefNetSynchronizationContextAwaiter"/> for the CEF thread.</returns>
public static CefNetSynchronizationContextAwaiter GetForThread(CefThreadId threadId)
{
CefNetSynchronizationContextAwaiter instance;
_SyncRoot.EnterReadLock();
try
{
_Awaiters.TryGetValue(threadId, out instance);
}
finally
{
_SyncRoot.ExitReadLock();
}
if (instance != null)
{
return(instance);
}
// These awaiters should have been added in the static constructor.
if (threadId == CefThreadId.Renderer || threadId == CefThreadId.UI)
{
throw new ArgumentOutOfRangeException(nameof(threadId));
}
_SyncRoot.EnterWriteLock();
try
{
if (!_Awaiters.TryGetValue(threadId, out instance))
{
instance = new CefNetSynchronizationContextAwaiter(threadId);
_Awaiters.Add(threadId, instance);
}
}
finally
{
_SyncRoot.ExitWriteLock();
}
return(instance);
}