Made the memory cache data structure derive MallocSizeOf, along with
manual size_of() implementations in malloc_size_of.
Added a Measurable struct that acts as a container for fields size_of() can be called for.
Added a new IpcReceiver used for listening to messages from the memory profiler,
and used run_with_memory reporting to register a memory reporter in the thread.
Now when a message from the memory profiler arrives, report includes sizes of public and private http caches.
Updated test file.
Servo currently uses `heapsize`, but Stylo/Gecko use `malloc_size_of`.
`malloc_size_of` is better -- it handles various cases that `heapsize` does not
-- so this patch changes Servo to use `malloc_size_of`.
This patch makes the following changes to the `malloc_size_of` crate.
- Adds `MallocSizeOf` trait implementations for numerous types, some built-in
(e.g. `VecDeque`), some external and Servo-only (e.g. `string_cache`).
- Makes `enclosing_size_of_op` optional, because vanilla jemalloc doesn't
support that operation.
- For `HashSet`/`HashMap`, falls back to a computed estimate when
`enclosing_size_of_op` isn't available.
- Adds an extern "C" `malloc_size_of` function that does the actual heap
measurement; this is based on the same functions from the `heapsize` crate.
This patch makes the following changes elsewhere.
- Converts all the uses of `heapsize` to instead use `malloc_size_of`.
- Disables the "heapsize"/"heap_size" feature for the external crates that
provide it.
- Removes the `HeapSizeOf` implementation from `hashglobe`.
- Adds `ignore` annotations to a few `Rc`/`Arc`, because `malloc_size_of`
doesn't derive those types, unlike `heapsize`.
This is used for two memory reporting improvements.
- It's used to distinguish "explicit" memory reports from others. This
mirrors the same categorization that is used in Firefox, and gives a single
tree that's the best place to look. It replaces the "pages" tree which
was always intended to be a temporary stand-in for "explicit".
- It's used to computed "heap-unclassified" values for both the jemalloc
and system heaps, both of which are placed into the "explicit" tree.
Example output:
```
| 114.99 MiB -- explicit
| 52.34 MiB -- jemalloc-heap-unclassified
| 46.14 MiB -- system-heap-unclassified
| 14.95 MiB -- url(file:///home/njn/moz/servo2/../servo-static-suite/wikipe
dia/Guardians%20of%20the%20Galaxy%20(film)%20-%20Wikipedia,%20the%20free%20encyc
lopedia.html)
| 7.32 MiB -- js
| 3.07 MiB -- malloc-heap
| 3.00 MiB -- gc-heap
| 2.49 MiB -- used
| 0.34 MiB -- decommitted
| 0.09 MiB -- unused
| 0.09 MiB -- admin
| 1.25 MiB -- non-heap
| 1.36 MiB -- layout-worker-3-local-context
| 1.34 MiB -- layout-worker-0-local-context
| 1.24 MiB -- layout-worker-1-local-context
| 1.24 MiB -- layout-worker-4-local-context
| 1.16 MiB -- layout-worker-2-local-context
| 0.89 MiB -- layout-worker-5-local-context
| 0.38 MiB -- layout-task
| 0.31 MiB -- display-list
| 0.07 MiB -- local-context
| 1.56 MiB -- compositor-task
| 0.78 MiB -- surface-map
| 0.78 MiB -- layer-tree
```
The heap-unclassified values dominate the "explicit" tree because reporter
coverage is still quite poor.
A rebuild after touching components/profile/mem.rs now takes 48 seconds (and
only rebuilds `profile` and `servo`) which is much lower than it used to be.
In comparison, a rebuild after touching components/profile_traits/mem.rs takes
294 seconds and rebuilds many more crates.
This change also removes some unnecessary crate dependencies in `net` and
`net_traits`.
