Free owned char* returns in the generated MEOS facade#21
Open
estebanzimanyi wants to merge 1 commit into
Open
Conversation
MEOS functions that return a non-const char* (temporal_out, the *_out / *_as_hexwkb / *_as_hexewkb family) transfer ownership of the allocation to the caller. Binding such a return as a JNR-FFI String copies the C string into a Java String and leaves the original native allocation unreferenced, so it accumulates on the native heap across repeated calls. The generator binds these returns as Pointer in the part interface; the public wrapper copies the string with getString(0), releases the allocation through sun.misc.Unsafe.freeMemory (the system free, avoiding JNR-FFI classloader-boundary issues), and returns the Java String. const char* returns (temporal_interp, temporal_subtype, geo_typename) are borrowed and remain String.
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
MEOS functions that return a non-const char* (temporal_out, the *_out / *_as_hexwkb / _as_hexewkb family) transfer ownership of the allocation to the caller. Binding such a return as a JNR-FFI String copies the C string into a Java String and leaves the original native allocation unreferenced, so it accumulates on the native heap across repeated calls. The generator binds these returns as Pointer in the part interface; the public wrapper copies the string with getString(0), releases the allocation through sun.misc.Unsafe.freeMemory (the system free, avoiding JNR-FFI classloader-boundary issues), and returns the Java String. const char returns (temporal_interp, temporal_subtype, geo_typename) are borrowed and remain String. The regenerated GeneratedFunctions facade and a unit test for the owned-vs-const classifier travel in the same commit.