Fix incorrect wrapping of a Datatype #151
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
`create_datatype` already returns an HDF5.Datatype object, so by wrapping again, the finalizer on the original object was allowed to run too early.
|
Good catch! |
jmert
added a commit
to jmert/HDF5.jl
that referenced
this pull request
Nov 24, 2020
By defining `Base.convert(::Type{hid_t}, x)` for all of the high-level
object types, implicit conversion to an integer is permitted.
This has the unfortunate consquence --- as found in JuliaIO/MAT.jl#145
and JuliaIO/MAT.jl#151 --- that incorrectly "wrapping" a wrapped object
was allowed, but doing so allows the garbage collector to reap the
object too early.
The main reason for allowing conversion from an object to integer
(namely `HDF5.hid_t`) is to support passing the objects to `ccall`s
without requiring reaching into the `obj.id` raw integer ID.
We can easily still allow this while disabling implicit conversion by
just replacing all definitions of `Base.convert` with `Base.cconvert`.
Doing this would have caught the mistake in MAT.jl at the Julia type
level rather than having to debug a runtime error.
This was referenced Nov 24, 2020
musm
pushed a commit
to JuliaIO/HDF5.jl
that referenced
this pull request
Nov 25, 2020
…#750) By defining `Base.convert(::Type{hid_t}, x)` for all of the high-level object types, implicit conversion to an integer is permitted. This has the unfortunate consquence --- as found in JuliaIO/MAT.jl#145 and JuliaIO/MAT.jl#151 --- that incorrectly "wrapping" a wrapped object was allowed, but doing so allows the garbage collector to reap the object too early. The main reason for allowing conversion from an object to integer (namely `HDF5.hid_t`) is to support passing the objects to `ccall`s without requiring reaching into the `obj.id` raw integer ID. We can easily still allow this while disabling implicit conversion by just replacing all definitions of `Base.convert` with `Base.cconvert`. Doing this would have caught the mistake in MAT.jl at the Julia type level rather than having to debug a runtime error.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This was noticed in the CI of #145.
create_datatypealready returns an HDF5.Datatype object, so bywrapping again, the finalizer on the original object was allowed to
run too early.