On Wed, 20 Dec 2023 11:16:03 GMT, Suchismith Roy <s...@openjdk.org> wrote:
>> J2SE agent does not start and throws error when it tries to find the shared >> library ibm_16_am. >> After searching for ibm_16_am.so ,the jvm agent throws and error as dll_load >> fails.It fails to identify the shared library ibm_16_am.a shared archive >> file on AIX. >> Hence we are providing a function which will additionally search for .a file >> on AIX ,when the search for .so file fails. > > Suchismith Roy has updated the pull request incrementally with one additional > commit since the last revision: > > Spaces fix > > > What happens if we accidentally attempt to load a "real" static library, > > > which is also named *.a? Would dlopen() then crash? What would happen? > > > I don't think the problem is with *.a . They would load as the default > > behaviour of the dlopen. It is only when the dlopen fails for *.so , we > > give another chance to check for .a file with the same name. > > No, what I meant, and what must be clarified before going forward with this > solution, is the following: > > * is _every_ `*.a` object on AIX loadable with `dlopen`, and will the result > be the same as when loading a `*.so` object > * or, if we present arbitrary `*.a` files to dlopen, is there a chance for > dlopen to crash or misbehave. > > Reason is that I was under the impression that *.a libraries are static > libraries and cannot be loaded dynamically. This is what you now try to do. > If we cannot safely answer this question, I would opt for a more narrow > solution by hard-wiring known alternative names. So, do the second *.a > attempt only for your `ibm_16_am.a` which you know works. That could also be > done in a reasonably maintainable manner. > In AIX, both static and dynamic libraries have *.a extension. And AIX also supports *.so files.Bascially shared objects in AIX have both *.a and *.so extension. Hence we need to implement this logic. If we try loading a static archive specifically ,how the dlopen would behave , that is something probably @JoKern65 can answer ? > > > Does this really have to be handled in the OpenJDK? What does J9 on AIX > > > do? Could this be done in a simpler way outside OpenJDK, e.g. by > > > providing an *.so variant of the library in question? Where does this > > > library come from? > > > I am not sure how J9 handles this. I would have to consult . > > J9 is Open Source, can't you just look? :) I did try comparing the file structures, and i do not see a similar file structure over there. I am unable to find the jvmTiAgent code and also os_aix file. So i am not sure which functions over there are doing the same functionality. You have any suggestion on how i can check and correlate ? > > > However as per current observation, this issue does not show up on Semuru. > > This issue is only happening on Adoptium. The team that release these file > > has always released *.a files which work fine for Semuru. > > I don't know what Semuru is. What is the context, is that a different VM? > Also OpenJDK? J9 derived? Semuru is J9 derived. ------------- PR Comment: https://git.openjdk.org/jdk/pull/16604#issuecomment-1865945011
