I'd like to point out that I know how to add/remove assembles to/from GAC. What I am asking for is if someone could explain me how does it work from the technical point of view. What's the point in putting dll's there - from the point of view of saving the resources.
Kind Regards
pk
The point of putting things in the GAC is so that multiple applications (even from different vendors) can access the same assembly. There is then one location where it can be updated and all applications which can properly access that version can use it. You also know that all assemblies in the GAC are digitally signed, so you know where the code came from (MS for example).
As far as loading into memory. Each application will have to load it on it's own.
This question gives a good argument for not using the GAC where you can avoid it.
And this question gives a couple of links to GAC demystification articles which may help your decision.
Related
The main software that we built is built using VB6 (old school, I know). We're having some problem for viewing a report using ActiveReports. We did many Debug DLLs and were unable to find why the problem happen. Note that restarting the server solves the issue, which brings us to think that the problem is resource related.
Is there a way I can see how much memory is being used by a DLL? I would like to see if an object in that dll might not be released correctly.
I tried using the performance monitor, but this is not as precise as needed.
Is there anything i could use to monitor a Dll's usage?
We are just doing it the hard way and monitoring a server running multiple instances of the DLL.
I'm using VB.net so keep that in mind.
I'm trying to create a program that is highly edible. Users will be able to change multiple things by just replacing the existing dlls. Kind of like a modding ability.
The new DLL shouldn't have to recreate every function though, it should only include the ones that it changes and then hook to the old dll for anything that it doesn't have. Is there a way to dynamically do this? Reference another dll (like a proxy) through yourself for anything that doesn't exist in its self?
Sorry if that is confusing. If it still confuses people, I'll draw a picture later =)
I'm Sorry, but it must be done this way. I have already set up everything in the manor and told clients (they have already started developing).
Sounds like you want to write a plugin architecture into your application, why re-invent the wheel, take a look at the Managed Extensibility Framework
I could use a little advice on naming my assemblies
(ie. When to turn a logical naming convention in my
namepaces into its own DLL).
I recently downloaded an example project with a ton of
class libraries in it that almost exactly mirrored the
namespaces.
To date, I have been building one massive class
library - MyProject.DLL - and referencing it in my
project. This way, I only need one library and can
access all namespaces using it.
But, in the project I downloaded, there seems to
be a DLL for every namespace (and, in some cases,
subcategoreis within a namespaces. For example,
SomeProj.Web.Security has SomeProj.Web.Dll and
SomeProj.Web.Security.Dll).
I understand that having multiple DLLs can make
it easier to focus on particular areas of the project
(and, probably, updating the DLL withing the site
easier) but is there a best practice here?
Thanks in advance...
OK, this pretty much answers my question:
http://msdn.microsoft.com/en-us/library/ms229048.aspx
I have an application that uses many different .NET managed DLL's as objects (each DLL implements a common interface). Each DLL also has a version number in the file name.
Suppose I create the object "Shape~01.dll." The application will use that DLL but it can't be replaced while the application is running. So, if I want to "upgrade" the shape dll I have to create "Shape~02.dll" and the application has to dynamically search for and load the newest dll everytime a shape is created and/or the user has to restart the application. It get's worse, each dll depends on the main .exe thus has to be rebuilt with the main .exe.
Is there an easier method to have dynamically "replaceable" objects?
Well, this isn't the best solution (still thinking about it), but you can unload dll files which will allow them to be replaced. That might be a quick stopgap solution until you come up with a better idea.
You don't mention which language/platform you are trying to accomplish this in, so I will answer for the .NET Framework.
If you want to do it the hard way look at Shadow Assemblies, this is the method that ASP.NET uses to keep the site updateable though it is using the files.
For a much easier method look at the new System.Addin namespace, this uses Shadow Assemblies under the hood and should do what you want.
Instead of polling when creating an object, why not just request notification from the system when the file system changes?
The class is System.IO.FileSystemWatcher in.NET.
For native code there are a few ways to watch a folder, but IANAND (I am not a native developer ;).
Although having said those things, you probably want to rethink the reason you need to change your objects so frequently, because it will probably take a lot of work to make it work.
You used the dynamic tag, so maybe you should try a dynamic language? :)
Since HTA applications are hosted within MSHTA.exe how does one provide a manifest? Plus I assume providing a MSHTA.exe.manifest could potentially break other HTA apps?
On Vista+, MSHTA.exe has an embedded manifest, which takes priority over external manifests, so your suggestion is not an option.
On XP/2003, yes, your suggestion would work, although it would be bad form, as is dropping files in System32 to modify the behavior of a system binary (especially make sure that any registration you put in the manifest are objects you are the only one to care about).
The proper solution, available on Win2003 and above, is to use the Microsoft.Windows.ActCtx object to instantiate your object given an explicit manifest reference.
For example:
var actCtx = WScript.CreateObject("Microsoft.Windows.ActCtx");
actCtx.Manifest = "myregfree.manifest";
var obj = actCtx.CreateObject("MyObj");
Perhaps, if this must work on XP as well, a path you may take is a combination of both solutions.
Edit: My answer is wrong, but I'll leave it here to avoid any similar wrong answers :)
If you question is can you access a COM object without registering it on the machine, then I think the answer is a tentative yes. However the work you would need to do would be substantial and would mean implementing a lot of the low level code that most development tools provide for you as a matter of course (Delphi, .NET, JAVA). You would need to interface with the dll directly (like you would a normal dll ), query its interfaces and call your methods.
If you have C, C++ knowledge, the way COM is accessed from these languages would give you some pointers.
Sorry I cant be of any more help.