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TcpClient, TcpListener class reuseIs there any way to recreate a TcpClient &/or TcpListener object using the
same IP address/port? The objects ago out of scope so I assume the garbage collector is destroying them, in which case I would think that I should be able to create a new instance of these objects with the same address. However, when I attempt to do so, I get the "Only one ussage of each socket address (protocol/network address) is normally permitted" message. this may happen if you do not call TcpListener.Stop method or
TcpClient.Close... if your objects just went out of scope GC collector will not call these methods, and unmanaged resources will still be allocated. Socket in this example is an unmanaged resource. In terms of Win32 it is a handle that describes the connection ( unmanaged resources ). You'll have to ensure that these Stop/Close are called in order not to get exceptions. Show quote "classAct" <class***@discussions.microsoft.com> wrote in message news:413D3AE9-1B72-452B-A957-282C79A5C4C3@microsoft.com... > Is there any way to recreate a TcpClient &/or TcpListener object using the > same IP address/port? The objects ago out of scope so I assume the garbage > collector is destroying them, in which case I would think that I should be > able to create a new instance of these objects with the same address. > However, when I attempt to do so, I get the "Only one ussage of each socket > address (protocol/network address) is normally permitted" message. Thanks, Vadym, but I have called TcpClient.Close/TcpListener.Stop before the
objects go out of scope (I did not include that info in my original post because those methods are always called in my code when their activity has ended -- I just pressumed that would have been read as understood, -- so much for presumption). The error message occurs after the .Close (or .Stop) methods are called and after the objects go out of scope and the objects are re-instantiated within the same instance of the application. If the application is terminated and then restarted, it works without error the first time the objects are created and used, but after that (until the app shutsdown) I get this error. It would seem to make sense to expose the SocketOption.ReuseAddress property in these classes but I see no such methods. I presume the TcpClient and TcpListener classes were derived from the Socket class, yes? Show quote "Vadym Stetsyak" wrote: > this may happen if you do not call TcpListener.Stop method or > TcpClient.Close... > > if your objects just went out of scope GC collector will not call these > methods, and unmanaged resources will still be allocated. Socket in this > example is an unmanaged resource. In terms of Win32 it is a handle that > describes the connection ( unmanaged resources ). > > You'll have to ensure that these Stop/Close are called in order not to get > exceptions. > > -- > Vadym Stetsyak aka Vadmyst > http://vadmyst.blogspot.com > > > "classAct" <class***@discussions.microsoft.com> wrote in message > news:413D3AE9-1B72-452B-A957-282C79A5C4C3@microsoft.com... > > Is there any way to recreate a TcpClient &/or TcpListener object using the > > same IP address/port? The objects ago out of scope so I assume the > garbage > > collector is destroying them, in which case I would think that I should be > > able to create a new instance of these objects with the same address. > > However, when I attempt to do so, I get the "Only one ussage of each > socket > > address (protocol/network address) is normally permitted" message. > > > UPDATE:
I have just determined that when stepping the through the application in the VS debugger, the recreated TcpClient/TcpListener objects work correctly EVERY TIME. This would lead me to suspect that there are timing issues related to the .NET runtime's release of the underlying Win32 Socket handles. Can anyone confirm or deny this hypothesis? Show quote "classAct" wrote: > Thanks, Vadym, but I have called TcpClient.Close/TcpListener.Stop before the > objects go out of scope (I did not include that info in my original post > because those methods are always called in my code when their activity has > ended -- I just pressumed that would have been read as understood, -- so much > for presumption). > > The error message occurs after the .Close (or .Stop) methods are called and > after the objects go out of scope and the objects are re-instantiated within > the same instance of the application. If the application is terminated and > then restarted, it works without error the first time the objects are created > and used, but after that (until the app shutsdown) I get this error. It > would seem to make sense to expose the SocketOption.ReuseAddress property in > these classes but I see no such methods. I presume the TcpClient and > TcpListener classes were derived from the Socket class, yes? > > "Vadym Stetsyak" wrote: > > > this may happen if you do not call TcpListener.Stop method or > > TcpClient.Close... > > > > if your objects just went out of scope GC collector will not call these > > methods, and unmanaged resources will still be allocated. Socket in this > > example is an unmanaged resource. In terms of Win32 it is a handle that > > describes the connection ( unmanaged resources ). > > > > You'll have to ensure that these Stop/Close are called in order not to get > > exceptions. > > > > -- > > Vadym Stetsyak aka Vadmyst > > http://vadmyst.blogspot.com > > > > > > "classAct" <class***@discussions.microsoft.com> wrote in message > > news:413D3AE9-1B72-452B-A957-282C79A5C4C3@microsoft.com... > > > Is there any way to recreate a TcpClient &/or TcpListener object using the > > > same IP address/port? The objects ago out of scope so I assume the > > garbage > > > collector is destroying them, in which case I would think that I should be > > > able to create a new instance of these objects with the same address. > > > However, when I attempt to do so, I get the "Only one ussage of each > > socket > > > address (protocol/network address) is normally permitted" message. > > > > > > At this point, posting a code sample that shows the issue would be most
helpful. I have not seen or heard about the issue you describe, so it may be a code issue. -- Show quoteWilliam Stacey [MVP] "classAct" <class***@discussions.microsoft.com> wrote in message news:CE22EC6C-55D4-44A7-B0BF-1160115084DB@microsoft.com... > UPDATE: > I have just determined that when stepping the through the application in > the > VS debugger, the recreated TcpClient/TcpListener objects work correctly > EVERY > TIME. This would lead me to suspect that there are timing issues related > to > the .NET runtime's release of the underlying Win32 Socket handles. Can > anyone confirm or deny this hypothesis? > > "classAct" wrote: > >> Thanks, Vadym, but I have called TcpClient.Close/TcpListener.Stop before >> the >> objects go out of scope (I did not include that info in my original post >> because those methods are always called in my code when their activity >> has >> ended -- I just pressumed that would have been read as understood, -- so >> much >> for presumption). >> >> The error message occurs after the .Close (or .Stop) methods are called >> and >> after the objects go out of scope and the objects are re-instantiated >> within >> the same instance of the application. If the application is terminated >> and >> then restarted, it works without error the first time the objects are >> created >> and used, but after that (until the app shutsdown) I get this error. It >> would seem to make sense to expose the SocketOption.ReuseAddress property >> in >> these classes but I see no such methods. I presume the TcpClient and >> TcpListener classes were derived from the Socket class, yes? >> >> "Vadym Stetsyak" wrote: >> >> > this may happen if you do not call TcpListener.Stop method or >> > TcpClient.Close... >> > >> > if your objects just went out of scope GC collector will not call these >> > methods, and unmanaged resources will still be allocated. Socket in >> > this >> > example is an unmanaged resource. In terms of Win32 it is a handle that >> > describes the connection ( unmanaged resources ). >> > >> > You'll have to ensure that these Stop/Close are called in order not to >> > get >> > exceptions. >> > >> > -- >> > Vadym Stetsyak aka Vadmyst >> > http://vadmyst.blogspot.com >> > >> > >> > "classAct" <class***@discussions.microsoft.com> wrote in message >> > news:413D3AE9-1B72-452B-A957-282C79A5C4C3@microsoft.com... >> > > Is there any way to recreate a TcpClient &/or TcpListener object >> > > using the >> > > same IP address/port? The objects ago out of scope so I assume the >> > garbage >> > > collector is destroying them, in which case I would think that I >> > > should be >> > > able to create a new instance of these objects with the same address. >> > > However, when I attempt to do so, I get the "Only one ussage of each >> > socket >> > > address (protocol/network address) is normally permitted" message. >> > >> > >> > Thanks, William, but I just found the solution to the problem. Earlier in
this thread, Vadym Statsyak reminded me that TcpListener.Close must be called before reopeing the object and I just found one execution path branch that did not include that call. After putting it in, all works as it should. Thanks. Show quote "William Stacey [MVP]" wrote: > At this point, posting a code sample that shows the issue would be most > helpful. I have not seen or heard about the issue you describe, so it may > be a code issue. > > -- > William Stacey [MVP] > > "classAct" <class***@discussions.microsoft.com> wrote in message > news:CE22EC6C-55D4-44A7-B0BF-1160115084DB@microsoft.com... > > UPDATE: > > I have just determined that when stepping the through the application in > > the > > VS debugger, the recreated TcpClient/TcpListener objects work correctly > > EVERY > > TIME. This would lead me to suspect that there are timing issues related > > to > > the .NET runtime's release of the underlying Win32 Socket handles. Can > > anyone confirm or deny this hypothesis? > > > > "classAct" wrote: > > > >> Thanks, Vadym, but I have called TcpClient.Close/TcpListener.Stop before > >> the > >> objects go out of scope (I did not include that info in my original post > >> because those methods are always called in my code when their activity > >> has > >> ended -- I just pressumed that would have been read as understood, -- so > >> much > >> for presumption). > >> > >> The error message occurs after the .Close (or .Stop) methods are called > >> and > >> after the objects go out of scope and the objects are re-instantiated > >> within > >> the same instance of the application. If the application is terminated > >> and > >> then restarted, it works without error the first time the objects are > >> created > >> and used, but after that (until the app shutsdown) I get this error. It > >> would seem to make sense to expose the SocketOption.ReuseAddress property > >> in > >> these classes but I see no such methods. I presume the TcpClient and > >> TcpListener classes were derived from the Socket class, yes? > >> > >> "Vadym Stetsyak" wrote: > >> > >> > this may happen if you do not call TcpListener.Stop method or > >> > TcpClient.Close... > >> > > >> > if your objects just went out of scope GC collector will not call these > >> > methods, and unmanaged resources will still be allocated. Socket in > >> > this > >> > example is an unmanaged resource. In terms of Win32 it is a handle that > >> > describes the connection ( unmanaged resources ). > >> > > >> > You'll have to ensure that these Stop/Close are called in order not to > >> > get > >> > exceptions. > >> > > >> > -- > >> > Vadym Stetsyak aka Vadmyst > >> > http://vadmyst.blogspot.com > >> > > >> > > >> > "classAct" <class***@discussions.microsoft.com> wrote in message > >> > news:413D3AE9-1B72-452B-A957-282C79A5C4C3@microsoft.com... > >> > > Is there any way to recreate a TcpClient &/or TcpListener object > >> > > using the > >> > > same IP address/port? The objects ago out of scope so I assume the > >> > garbage > >> > > collector is destroying them, in which case I would think that I > >> > > should be > >> > > able to create a new instance of these objects with the same address. > >> > > However, when I attempt to do so, I get the "Only one ussage of each > >> > socket > >> > > address (protocol/network address) is normally permitted" message. > >> > > >> > > >> > > > >  |
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