Add shm_open, shm_unlink, and mmap to Unix LibCAPI

[magneticflux-]

• Documentation for shm_open.
• Documentation for shm_unlink.
• Documentation for mmap.

[gkoudjou]

Hello,

While loading a shared library, i ran into the issue described here.

Here is the error message :

java: symbol lookup error: xxxxxx.so: undefined symbol: shm_unlink

Since, the initial post dates is one year old, is there any chance that this feature will be take into account in the coming months ?

Thanks

[magneticflux-]

@gkoudjou I implemented this myself a while back here: https://github.com/magneticflux-/jvm-shared-memory

You can view the way I access each native library as an example. I forgot to license it since it was for personal use, but I'll put it under the LGPL real quick.

[dbwiddis]

@magneticflux- your mapping of mmap uses a long for the offset argument. This will fail on most 32-bit Linux distros. The correct mapping should account for that argument being off_t which can be 32-bit or 64-bit. See discussion on #1202.

@gkoudjou JNA is a user-supported library. Simply asking for a feature doesn't get it, often after several years. In this case, I've happened to be working on this myself for other reasons and will submit it when the off_t discussion is resolved. We need more users to submit their mappings to the project to avoid duplication.

[magneticflux-]

@dbwiddis Thanks for the heads up! I've only encountered 64-bit systems so far but I'll make sure to fix it in case it eventually gets used on a 32-bit system.

[dbwiddis]

This can be closed as these mappings were committed in #1202