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

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()?

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

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.\

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.

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;
>	}

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.
}

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

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.