digitalmars.D.learn - Howto catch SocketOSException?

Jolly James (4/25) Mar 25 2017 How do you catch an std.socket.SocketOSException?

bauss (8/39) Mar 25 2017 This part:

Jolly James (8/45) Mar 25 2017 I know that inheritance stuff, but none (!) of them catches that

Adam D. Ruppe (3/8) Mar 25 2017 Try putting it in the try anyway and see what happens.

Jolly James (4/12) Mar 26 2017 Unfortunately not working either. I should not forget to mention

Jolly James (6/41) Mar 26 2017 Found out something: You cannot catch any exception thrown in the

bauss (27/37) Mar 26 2017 Chances are it's invoked in another thread and thus you can't

Jolly James (3/31) Mar 26 2017 If you want try to help me, mabye this helps you:

Jolly James (3/7) Mar 27 2017 Finally found the bug: I had a logical error in the way how I

Jolly James <j.j jmail.com> writes:

How do you catch an std.socket.SocketOSException?


The following does not work, as the exception occurs anyway and 
leads to a crash:

import ae.net.asockets;

void main(string[] args)
{
	TcpServer tcp = new TcpServer();

	try
	{
		tcp.listen(2345, "127.0.0.1c");
		// '...c' makes the IP address invalid
	}
	catch (std.socket.SocketOSException e)
	{
		return;
	}
	catch (Exception e)
	{
		return;
	}

	socketManager.loop();
}

Output:
std.socket.SocketOSException std\socket.d(975): getaddrinfo 
error: Unknown Host

Mar 25 2017

bauss <jj_1337 live.dk> writes:

On Sunday, 26 March 2017 at 00:34:03 UTC, Jolly James wrote:
 How do you catch an std.socket.SocketOSException?


 The following does not work, as the exception occurs anyway and 
 leads to a crash:

import ae.net.asockets;

void main(string[] args)
{
	TcpServer tcp = new TcpServer();

	try
	{
		tcp.listen(2345, "127.0.0.1c");
		// '...c' makes the IP address invalid
	}
	catch (std.socket.SocketOSException e)
	{
		return;
	}
	catch (Exception e)
	{
		return;
	}

	socketManager.loop();
}

 Output:
std.socket.SocketOSException std\socket.d(975): getaddrinfo 
error: Unknown Host


This part:
catch (std.socket.SocketOSException e)
	{
		return;
	}

Is redundant, because SocketOSException inherits SocketException 
which inherits Exception.

It should already be caught by catch (Exception e)

You should have a full stacktrace, chances are that it's invoked 
in your loop()?

Mar 25 2017

Jolly James <j.j jmail.com> writes:

On Sunday, 26 March 2017 at 01:22:24 UTC, bauss wrote:
 On Sunday, 26 March 2017 at 00:34:03 UTC, Jolly James wrote:
[...]


 This part:
 catch (std.socket.SocketOSException e)
[...]

 [...]

I know that inheritance stuff, but none (!) of them catches that 
strange exception either. You can ignore the loop()-method. It is 
not called as the application will never reach this statement, 
because it cannot, because it crashes already in the 
listen()-method in consequence of the exception that does not get 
caught by the try-catch block.


std.socket.SocketOSException std\socket.d(975): getaddrinfo 
error: Unknow host.
----------------
	0x004205BE in pure  safe bool 
std.exception.enforce!(bool).enforce(bool, lazy object.Throwable)
	0x0040D3A2 in  trusted std.socket.AddressInfo[] 
std.socket.getAddressInfo!(immutable(char)[], 
std.socket.AddressInfoFlags, std.socket.SocketType, 
std.socket.ProtocolType).getAddressInfo(const(char[]), 
immutable(char)[], std.socket.AddressInfoFlags, 
std.socket.SocketType, std.socket.ProtocolType).__lambda7()
	0x0040D37B in  safe std.socket.AddressInfo[] 
std.socket.getAddressInfo!(immutable(char)[], 
std.socket.AddressInfoFlags, std.socket.SocketType, 
std.socket.ProtocolType).getAddressInfo(const(char[]), 
immutable(char)[], std.socket.AddressInfoFlags, 
std.socket.SocketType, std.socket.ProtocolType) at 
C:\dlang\dmd2\windows\bin\..\..\src\phobos\std\socket.d(945)
	0x00404DAF in ushort ae.net.asockets.TcpServer.listen(ushort, 
immutable(char)[]) at C:\Users\jolly\src\ae\net\asockets.d(1242)
	0x00416749 in _Dmain at C:\Users\jolly\src\app.d(48)
	0x00423597 in 
D2rt6dmain211_d_run_mainUiPPaPUAAaZiZ6runAllMFZ9__lambda1MFZv
	0x0042355B in void rt.dmain2._d_run_main(int, char**, extern 
(C) int function(char[][])*).runAll()
	0x0042345C in _d_run_main
	0x00417D74 in main at C:\Users\jolly\src\ae\net\asockets.d(7)
	0x00443EBD in mainCRTStartup
	0x757362C4 in BaseThreadInitThunk
	0x773C0FD9 in RtlSubscribeWnfStateChangeNotification
	0x773C0FA4 in RtlSubscribeWnfStateChangeNotification

↑ stacktrace

Mar 25 2017

Adam D. Ruppe <destructionator gmail.com> writes:

On Sunday, 26 March 2017 at 02:24:56 UTC, Jolly James wrote:
 You can ignore the loop()-method. It is not called as the 
 application will never reach this statement, because it cannot, 
 because it crashes already in the listen()-method in 
 consequence of the exception that does not get caught by the 
 try-catch block.

Try putting it in the try anyway and see what happens.

It is an async socket library, they can do weird things.\

Mar 25 2017

Jolly James <j.j jmail.com> writes:

On Sunday, 26 March 2017 at 02:41:46 UTC, Adam D. Ruppe wrote:
 On Sunday, 26 March 2017 at 02:24:56 UTC, Jolly James wrote:
 You can ignore the loop()-method. It is not called as the 
 application will never reach this statement, because it 
 cannot, because it crashes already in the listen()-method in 
 consequence of the exception that does not get caught by the 
 try-catch block.

 Try putting it in the try anyway and see what happens.

 It is an async socket library, they can do weird things.\

Unfortunately not working either. I should not forget to mention 
that the exception also raises when the code does not contain the 
loop()-call.

Mar 26 2017

Jolly James <j.j jmail.com> writes:

On Sunday, 26 March 2017 at 11:35:00 UTC, Jolly James wrote:
 On Sunday, 26 March 2017 at 02:41:46 UTC, Adam D. Ruppe wrote:
 On Sunday, 26 March 2017 at 02:24:56 UTC, Jolly James wrote:
 You can ignore the loop()-method. It is not called as the 
 application will never reach this statement, because it 
 cannot, because it crashes already in the listen()-method in 
 consequence of the exception that does not get caught by the 
 try-catch block.

 Try putting it in the try anyway and see what happens.

 It is an async socket library, they can do weird things.\

 Unfortunately not working either. I should not forget to 
 mention that the exception also raises when the code does not 
 contain the loop()-call.

Found out something: You cannot catch any exception thrown in the 
listen()-method in general.


■ Original code:
auto addressInfos = getAddressInfo(addr, to!string(port), 
AddressInfoFlags.PASSIVE, SocketType.STREAM, ProtocolType.TCP);


■ Modified one:
AddressInfo[] addressInfos;

try
{
	addressInfos = getAddressInfo(addr, to!string(port), 
AddressInfoFlags.PASSIVE, SocketType.STREAM, ProtocolType.TCP);
}
catch(SocketOSException e)
{
	throw new Exception("Invalid address: " ~ addr, e);
}


■ Not working try-catch:
	try
	{
		tcp.listen(2345, "127.0.0.1c");
		socketManager.loop();
	}
	catch (Exception e)
	{
		return;
	}

Mar 26 2017

bauss <jj_1337 live.dk> writes:

On Sunday, 26 March 2017 at 11:46:39 UTC, Jolly James wrote:
 On Sunday, 26 March 2017 at 11:35:00 UTC, Jolly James wrote:
 [...]

 Found out something: You cannot catch any exception thrown in 
 the listen()-method in general.


 ■ Original code:
[...]


 ■ Modified one:
[...]


 ■ Not working try-catch:
[...]


Chances are it's invoked in another thread and thus you can't 
catch it like that.

To sum it up.

Ex.

void thisFunctionThrows() { ... }

void ableToCatch() {
     try {
         thisFunctionThrows();
     }
     catch (Exception e) {
         // We can catch the exception ...
     }
}

void notAbleToCatch() {
     try {
         spawn(&thisFunctionThrows);
     }
     catch (Exception e) {
         // We cannot catch the exception ...
     }
}

void ableToCatchToo() {
     spawn(&ableToCatch); // We're able to handle the exception, 
because the try/catch is handled in the thread that calls the 
function that throws.
}

Mar 26 2017

Jolly James <j.j jmail.com> writes:

On Sunday, 26 March 2017 at 18:50:13 UTC, bauss wrote:
 On Sunday, 26 March 2017 at 11:46:39 UTC, Jolly James wrote:
[...]


 Chances are it's invoked in another thread and thus you can't 
 catch it like that.

 To sum it up.

 Ex.

 void thisFunctionThrows() { ... }

 void ableToCatch() {
     try {
         thisFunctionThrows();
     }
     catch (Exception e) {
         // We can catch the exception ...
     }
 }

 void notAbleToCatch() {
     try {
         spawn(&thisFunctionThrows);
     }
     catch (Exception e) {
         // We cannot catch the exception ...
     }
 }

 void ableToCatchToo() {
     spawn(&ableToCatch); // We're able to handle the exception, 
 because the try/catch is handled in the thread that calls the 
 function that throws.
 }

If you want try to help me, mabye this helps you:
https://github.com/CyberShadow/ae/blob/master/net/asockets.d#L1237

Mar 26 2017

Jolly James <j.j jmail.com> writes:

On Sunday, 26 March 2017 at 21:57:29 UTC, Jolly James wrote:
 On Sunday, 26 March 2017 at 18:50:13 UTC, bauss wrote:
 [...]

 If you want try to help me, mabye this helps you:
 https://github.com/CyberShadow/ae/blob/master/net/asockets.d#L1237

Finally found the bug: I had a logical error in the way how I 
used this code.

Mar 27 2017

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digitalmars.D.learn - Howto catch SocketOSException?