[ML] Convert std::shared_ptrs to std::unique_ptrs where possible #115
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
…ing and restoring
tveasey
force-pushed
the
enhancement/unique-ptrs-fix
branch
from
344ec5f
to
90f22e2
Compare
edsavage
approved these changes
Jun 8, 2018
tveasey
added a commit
to tveasey/ml-cpp-1
that referenced
this pull request
Jun 8, 2018
…stic#115) Many of our current uses of shared pointer date from when not all our target platforms were C++11 compliant and in particular move semantics weren't available. Now that they all are, we can switch these to std::unique_ptr. This has a few advantages: i) it saves us 16 bytes (8 for the extra pointer to the reference count and 8 for the reference count) per instance, ii) it avoids atomic updates of the reference count, iii) it forces one to have the correct copy semantics in such cases. For example, this showed up that we had an implicit shallow copy (not appropriate) on our naive Bayes implementation and fixing this showed up a bug in restore. This also fixes an error in memory accounting for shared pointers, which wasn't including the extra memory for the reference count.
tveasey
added a commit
that referenced
this pull request
Jun 14, 2018
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Outdated suggestions cannot be applied.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.
As originally implemented in #108, the fix for
m_Exemplarbeing null after restore relied on writing additional state. This fails if the fix is present on master and not 6.4: elastic/elasticsearch#30982. In fact, this doesn't need to be fixed by modifying the state we write, instead we can just as well pass this into the restore constructor.In the first commit this reapplies #108, which I reverted from master. In the second I've implemented the alternative fix. This commit is therefore the only one which needs reviewing.
Just to reiterate, the affects on results should be small:
CNaiveBayes. This code isn't released, but as it is the exemplar would wind up null after a persist and restore. This is then a crash waiting to happen: since we'll try and clone it if we get a new (classification) class down the road.