unlock file before closing

[dschwoerer]

Unlocking ensures that if a new thread has spawned and thus there are
still copies of the fd around, the file get's still unlocked and can be
read again.

[derobins]

This needs a test. Probably something in test/swmr.c, where we already have a test_file_locking() test that could be expanded.

[lrknox]

Please note also that the 1.10/master branch is used exclusively for HDF5 1.10 releases. Pull requests should preferably go to the develop branch first, or for changes appropriate for only HDF5 1.10, to the hdf5_1_10 branch.

[dschwoerer]

This needs a test. Probably something in test/swmr.c, where we already have a test_file_locking() test that could be expanded.

Something like:
open file (with locking), fork, close in one thread, try to open again, ensure it is open-able, delete other thread?

[dschwoerer]

Please note also that the 1.10/master branch is used exclusively for HDF5 1.10 releases. Pull requests should preferably go to the develop branch first, or for changes appropriate for only HDF5 1.10, to the hdf5_1_10 branch.

Thanks for the info, I will rebase to develop ...

[derobins]

This needs a test. Probably something in test/swmr.c, where we already have a test_file_locking() test that could be expanded.

Something like: open file (with locking), fork, close in one thread, try to open again, ensure it is open-able, delete other thread?

Something like that, but keep in mind that Windows doesn't have fork. I can map a test that does fork + exec to Windows concepts, but the "fork then do one thing if you are the parent and another if you are the child" pattern is not a thing on Windows.