Track Environment fields in heap snapshot? #26776
Labels
lib / src
Issues and PRs related to general changes in the lib or src directory.
Comments
|
cc @nodejs/embedders |
2 tasks
targos
pushed a commit
to targos/node
that referenced
this issue
Mar 27, 2019
PR-URL: nodejs#26824 Refs: nodejs#26776 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
targos
pushed a commit
to targos/node
that referenced
this issue
Mar 27, 2019
PR-URL: nodejs#26824 Refs: nodejs#26776 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
targos
pushed a commit
to targos/node
that referenced
this issue
Mar 27, 2019
PR-URL: nodejs#26824 Refs: nodejs#26776 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
targos
pushed a commit
to targos/node
that referenced
this issue
Mar 27, 2019
PR-URL: nodejs#26824 Refs: nodejs#26776 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
targos
pushed a commit
to targos/node
that referenced
this issue
Mar 27, 2019
PR-URL: nodejs#26824 Refs: nodejs#26776 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
targos
pushed a commit
to targos/node
that referenced
this issue
Mar 27, 2019
PR-URL: nodejs#26824 Refs: nodejs#26776 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
3 tasks
joyeecheung
added a commit
that referenced
this issue
Apr 4, 2019
This allows us to track the essentially-global objects in Environment in the heap snapshot. Note that this patch only tracks the fields that can be tracked correctly. There are still several types of fields that cannot be tracked: - v8::Data including v8::Private, v8::ObjectTemplate etc. - Internal types that do not implement MemoryRetainer yet - STL containers with MemoryRetainer* inside - STL containers with numeric types inside that should not have their nodes elided e.g. numeric keys in maps. The `BaseObject`s are now no longer globals. They are tracked as arguments in CleanupHookCallbacks referenced by the Environment node. This model is closer to how their lifetime is managed internally. To track the per-environment strong persistent properties, this patch divides them into those that are also `v8::Value` and those that are just `v8::Data`. The values can be tracked by the current memory tracker while the data cannot. This patch also implements the `MemoryRetainer` interface in several internal classes so that they can be tracked in the heap snapshot. PR-URL: #27018 Refs: #26776 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
BethGriggs
pushed a commit
that referenced
this issue
Apr 4, 2019
This allows us to track the essentially-global objects in Environment in the heap snapshot. Note that this patch only tracks the fields that can be tracked correctly. There are still several types of fields that cannot be tracked: - v8::Data including v8::Private, v8::ObjectTemplate etc. - Internal types that do not implement MemoryRetainer yet - STL containers with MemoryRetainer* inside - STL containers with numeric types inside that should not have their nodes elided e.g. numeric keys in maps. The `BaseObject`s are now no longer globals. They are tracked as arguments in CleanupHookCallbacks referenced by the Environment node. This model is closer to how their lifetime is managed internally. To track the per-environment strong persistent properties, this patch divides them into those that are also `v8::Value` and those that are just `v8::Data`. The values can be tracked by the current memory tracker while the data cannot. This patch also implements the `MemoryRetainer` interface in several internal classes so that they can be tracked in the heap snapshot. PR-URL: #27018 Refs: #26776 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
|
@joyeecheung - will this enable a debugger (like llnode) walk through the reference chains of C++ objects, starting with a JS object? the use case is debugging native memory leaks, that has JS objects as anchors. |
|
@gireeshpunathil I don't think it's going to be useful for llnode, but it adds more information into the heap snapshots (essentially allowing the heap snapshots to track C++ memory as well) |
jasnell
added
the
lib / src
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
At the moment, the Environment fields are not tracked by the heap snapshot (unless they are referenced by some other objects that implements the
MemoryRetainerinterface) - for example, you can't see any of theAliasedBufferin the Environment when looking at a heap snapshot taken after bootstrap. Considering the amount of things we attach to the Environment, it should be pretty useful to track those fields in the heap snapshot instead of keeping them invisible for no particular reason.I am thinking about having Environment implmement
MemoryRetainer, are there any concerns around having it inherit from an abstract class? (considering this is semi-exposed to embedders).The text was updated successfully, but these errors were encountered: