Question

我有这个方法，它在多个连接上的mysql数据库上执行sql命令。

public async Task<long[][]> ExecuteCommand(string sqlCommand, int tries, int concurrent,
        CancellationToken cancellationToken)
    {
        EnsureConnections(concurrent);

        //This line takes about 2 seconds before hitting the log method when using mysql, postgres and sqlserver execute this line instantly and block at Task.WhenAll
        var tasks = Connections
            .Select(connection => connection.ExecuteQuery(sqlCommand, tries, cancellationToken))
            .ToList();
        Log.Debug("Completed gathering tasks");

        return await Task.WhenAll(tasks);
    }

这是connection.executeQuery：

public override async Task<long[]> ExecuteQuery(string sqlCommand, int tries,
        CancellationToken cancellationToken)
    {
        IsExecuting = true;

        var times = await FunctionTimer.GetOperationTimesAsync(async () =>
        {
            using (var command =
                new MySqlCommand(sqlCommand, BaseConnection as MySql.Data.MySqlClient.MySqlConnection))
            {
                command.CommandTimeout = 0;
                await command.ExecuteNonQueryAsync(cancellationToken);
            }
        }, tries, cancellationToken);

        IsExecuting = false;
        return times;
    }

正如您所看到的，ExecuteQuery方法是异步的，而ExecuteNonQueryAsync也是异步的。奇怪的是我也为Postgres和SQL Server设置了这个设置，它们都应该阻止它们（在Task.WhenAll（任务））。当我只将任务放在列表中时，为什么mysql版本会阻塞？

C＃Task似乎在没有等待的情况下阻止

0 个答案: