C# Handling Task Cancellations/Timeouts and Exceptions
1
$begingroup$
I am very new to Tasks and therefore new to handling task cancellations and task exceptions.
I wrote this method that gets a List which is then used to populate an ObsservableCollection shown in a ListView but I am not sure if I am handling cancellations and exceptions properly.
I would like to cancel awaited tasks if they dont execute successfuly within 10 seconds time frame. In addition, I would like to handle any exceptions and to properly release any resources, hence I am using the "using" statements below.
public override async Task<IList<MyModel>> GetDataAsync(string Id)
{
try
{
// 1. Connecting TcpClient may take up to 90sec? How to time that to 10sec?
using (TcpClient client = new TcpClient(ip, port))
using (NetworkStream stream = client.GetStream())
{
byte messageBytes = GetMessageBytes(Id);
using (var writeCts = new CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
await stream.WriteAsync(messageBytes, 0, messageBytes.Length, writeCts.Token);
await stream.FlushAsync(); // 2. Do I even need this?
}
byte buffer = new byte[1024];
StringBuilder builder = new StringBuilder();
int bytesRead = 0;
using (var readCts = new CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
while (stream.DataAvailable)
{
bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length, readCts.Token);
builder.AppendFormat("{0}", Encoding.ASCII.GetString(buffer, 0, bytesRead));
}
}
string msg = receivedMessage.ToString();
}
return ParseMessageIntoList(msg); // parses message into IList<MyModel>
}
catch (OperationCancelledException ex1)
{
// 3. If 10 second timeout expires, I expect to hit this catch block but I dont see it happen?
Debug.WriteLine(ex.Message);
}
catch (Exception ex2)
{
// Catch any other exception and return empty list
return await Task.FromResult<IList<MyModel>>(new List<MyModel>());
}
}
c# error-handling asynchronous tcp xamarin
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cd491415cd491415
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1
$begingroup$
I am very new to Tasks and therefore new to handling task cancellations and task exceptions.
I wrote this method that gets a List which is then used to populate an ObsservableCollection shown in a ListView but I am not sure if I am handling cancellations and exceptions properly.
I would like to cancel awaited tasks if they dont execute successfuly within 10 seconds time frame. In addition, I would like to handle any exceptions and to properly release any resources, hence I am using the "using" statements below.
public override async Task<IList<MyModel>> GetDataAsync(string Id)
{
try
{
// 1. Connecting TcpClient may take up to 90sec? How to time that to 10sec?
using (TcpClient client = new TcpClient(ip, port))
using (NetworkStream stream = client.GetStream())
{
byte messageBytes = GetMessageBytes(Id);
using (var writeCts = new CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
await stream.WriteAsync(messageBytes, 0, messageBytes.Length, writeCts.Token);
await stream.FlushAsync(); // 2. Do I even need this?
}
byte buffer = new byte[1024];
StringBuilder builder = new StringBuilder();
int bytesRead = 0;
using (var readCts = new CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
while (stream.DataAvailable)
{
bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length, readCts.Token);
builder.AppendFormat("{0}", Encoding.ASCII.GetString(buffer, 0, bytesRead));
}
}
string msg = receivedMessage.ToString();
}
return ParseMessageIntoList(msg); // parses message into IList<MyModel>
}
catch (OperationCancelledException ex1)
{
// 3. If 10 second timeout expires, I expect to hit this catch block but I dont see it happen?
Debug.WriteLine(ex.Message);
}
catch (Exception ex2)
{
// Catch any other exception and return empty list
return await Task.FromResult<IList<MyModel>>(new List<MyModel>());
}
}
c# error-handling asynchronous tcp xamarin
asked 2 hours ago
cd491415cd491415
1061
New contributor
cd491415 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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add a comment |
1
1
1
$begingroup$
I am very new to Tasks and therefore new to handling task cancellations and task exceptions.
I wrote this method that gets a List which is then used to populate an ObsservableCollection shown in a ListView but I am not sure if I am handling cancellations and exceptions properly.
I would like to cancel awaited tasks if they dont execute successfuly within 10 seconds time frame. In addition, I would like to handle any exceptions and to properly release any resources, hence I am using the "using" statements below.
public override async Task<IList<MyModel>> GetDataAsync(string Id)
{
try
{
// 1. Connecting TcpClient may take up to 90sec? How to time that to 10sec?
using (TcpClient client = new TcpClient(ip, port))
using (NetworkStream stream = client.GetStream())
{
byte messageBytes = GetMessageBytes(Id);
using (var writeCts = new CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
await stream.WriteAsync(messageBytes, 0, messageBytes.Length, writeCts.Token);
await stream.FlushAsync(); // 2. Do I even need this?
}
byte buffer = new byte[1024];
StringBuilder builder = new StringBuilder();
int bytesRead = 0;
using (var readCts = new CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
while (stream.DataAvailable)
{
bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length, readCts.Token);
builder.AppendFormat("{0}", Encoding.ASCII.GetString(buffer, 0, bytesRead));
}
}
string msg = receivedMessage.ToString();
}
return ParseMessageIntoList(msg); // parses message into IList<MyModel>
}
catch (OperationCancelledException ex1)
{
// 3. If 10 second timeout expires, I expect to hit this catch block but I dont see it happen?
Debug.WriteLine(ex.Message);
}
catch (Exception ex2)
{
// Catch any other exception and return empty list
return await Task.FromResult<IList<MyModel>>(new List<MyModel>());
}
}
c# error-handling asynchronous tcp xamarin
asked 2 hours ago
cd491415cd491415
1061
New contributor
cd491415 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
I am very new to Tasks and therefore new to handling task cancellations and task exceptions.
I wrote this method that gets a List which is then used to populate an ObsservableCollection shown in a ListView but I am not sure if I am handling cancellations and exceptions properly.
I would like to cancel awaited tasks if they dont execute successfuly within 10 seconds time frame. In addition, I would like to handle any exceptions and to properly release any resources, hence I am using the "using" statements below.
public override async Task<IList<MyModel>> GetDataAsync(string Id)
{
try
{
// 1. Connecting TcpClient may take up to 90sec? How to time that to 10sec?
using (TcpClient client = new TcpClient(ip, port))
using (NetworkStream stream = client.GetStream())
{
byte messageBytes = GetMessageBytes(Id);
using (var writeCts = new CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
await stream.WriteAsync(messageBytes, 0, messageBytes.Length, writeCts.Token);
await stream.FlushAsync(); // 2. Do I even need this?
}
byte buffer = new byte[1024];
StringBuilder builder = new StringBuilder();
int bytesRead = 0;
using (var readCts = new CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
while (stream.DataAvailable)
{
bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length, readCts.Token);
builder.AppendFormat("{0}", Encoding.ASCII.GetString(buffer, 0, bytesRead));
}
}
string msg = receivedMessage.ToString();
}
return ParseMessageIntoList(msg); // parses message into IList<MyModel>
}
catch (OperationCancelledException ex1)
{
// 3. If 10 second timeout expires, I expect to hit this catch block but I dont see it happen?
Debug.WriteLine(ex.Message);
}
catch (Exception ex2)
{
// Catch any other exception and return empty list
return await Task.FromResult<IList<MyModel>>(new List<MyModel>());
}
}
c# error-handling asynchronous tcp xamarin
c# error-handling asynchronous tcp xamarin
asked 2 hours ago
cd491415cd491415
1061
New contributor
cd491415 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
cd491415cd491415
1061
New contributor
cd491415 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
cd491415cd491415
1061
New contributor
cd491415 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
cd491415cd491415
1061
asked 2 hours ago
cd491415cd491415
1061
1061
New contributor
cd491415 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
cd491415 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
cd491415 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
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1 Answer
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$begingroup$
Try this. I think it should throw as you expect.
using (var writeCts = new System.Threading.CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
writeCts.Token.ThrowIfCancellationRequested();
await stream.WriteAsync(messageBytes, 0, messageBytes.Length, writeCts.Token);
await stream.FlushAsync(); // 2. Do I even need this? I think so. This ensures it has finished writing to the actual hardware.
}
see here for how to set a connect timeout on your tcpclient
https://stackoverflow.com/questions/17118632/how-to-set-the-timeout-for-a-tcpclient
answered 1 hour ago
justjoshinjustjoshin
12
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0
$begingroup$
Try this. I think it should throw as you expect.
using (var writeCts = new System.Threading.CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
writeCts.Token.ThrowIfCancellationRequested();
await stream.WriteAsync(messageBytes, 0, messageBytes.Length, writeCts.Token);
await stream.FlushAsync(); // 2. Do I even need this? I think so. This ensures it has finished writing to the actual hardware.
}
see here for how to set a connect timeout on your tcpclient
https://stackoverflow.com/questions/17118632/how-to-set-the-timeout-for-a-tcpclient
answered 1 hour ago
justjoshinjustjoshin
12
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justjoshin is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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add a comment |
0
$begingroup$
Try this. I think it should throw as you expect.
using (var writeCts = new System.Threading.CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
writeCts.Token.ThrowIfCancellationRequested();
await stream.WriteAsync(messageBytes, 0, messageBytes.Length, writeCts.Token);
await stream.FlushAsync(); // 2. Do I even need this? I think so. This ensures it has finished writing to the actual hardware.
}
see here for how to set a connect timeout on your tcpclient
https://stackoverflow.com/questions/17118632/how-to-set-the-timeout-for-a-tcpclient
answered 1 hour ago
justjoshinjustjoshin
12
New contributor
justjoshin is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
0
0
0
$begingroup$
Try this. I think it should throw as you expect.
using (var writeCts = new System.Threading.CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
writeCts.Token.ThrowIfCancellationRequested();
await stream.WriteAsync(messageBytes, 0, messageBytes.Length, writeCts.Token);
await stream.FlushAsync(); // 2. Do I even need this? I think so. This ensures it has finished writing to the actual hardware.
}
see here for how to set a connect timeout on your tcpclient
https://stackoverflow.com/questions/17118632/how-to-set-the-timeout-for-a-tcpclient
answered 1 hour ago
justjoshinjustjoshin
12
New contributor
justjoshin is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
Try this. I think it should throw as you expect.
using (var writeCts = new System.Threading.CancellationTokenSource(TimeSpan.FromSeconds(10)))
{
writeCts.Token.ThrowIfCancellationRequested();
await stream.WriteAsync(messageBytes, 0, messageBytes.Length, writeCts.Token);
await stream.FlushAsync(); // 2. Do I even need this? I think so. This ensures it has finished writing to the actual hardware.
}
see here for how to set a connect timeout on your tcpclient
https://stackoverflow.com/questions/17118632/how-to-set-the-timeout-for-a-tcpclient
answered 1 hour ago
justjoshinjustjoshin
12
New contributor
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edited 53 mins ago
answered 1 hour ago
justjoshinjustjoshin
12
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answered 1 hour ago
justjoshinjustjoshin
12
answered 1 hour ago
justjoshinjustjoshin
12
12
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