This adds a PrefName wrapper that allows use to avoid copying the pref name
string in the fast root pref branch case, but also allows to create a new
string in the slower non-root pref branch case. By creating a new string we
avoid the odd behavior of mutating the pref branch name with each retrieval.
MozReview-Commit-ID: HGCLbpGmKrr
This patch removes checking of all the callback calls in memory reporter
CollectReport() functions, because it's not useful.
The patch also does some associated clean-up.
- Replaces some uses of nsIMemoryReporterCallback with the preferred
nsIHandleReportCallback typedef.
- Replaces aCallback/aCb/aClosure with aHandleRepor/aData for CollectReports()
parameter names, for consistency.
- Adds MOZ_MUST_USE/[must_use] in a few places in nsIMemoryReporter.idl.
- Uses the MOZ_COLLECT_REPORT macro in all suitable places.
Overall the patch reduces code size by ~300 lines and reduces the size of
libxul by about 37 KiB on my Linux64 builds.
This patch makes most Run() declarations in subclasses of nsIRunnable have the
same form: |NS_IMETHOD Run() override|.
As a result of these changes, I had to add |override| to a couple of other
functions to satisfy clang's -Winconsistent-missing-override warning.
Don't send any preferences that have a string value that is longer
than MAX_ADVISABLE_PREF_LENGTH. This is intended to mitigate OOM
issues, as I've seen a parent process crash trying to create a 100mb
message to send to the child. Such users likely cannot use e10s at
all.
This has a test for all combinations of setting the default and user
values of a preference to large or small string values, or not setting
them at all.
I manually verified that filtering out preferences reduces the size of
the IPC::Message that is sent to the child by printing out the size of
the reply message in PContentParent::OnMessageReceived().
Returning outparams with UniquePtr is not convenient or idiomatic, so in
addition to removing nsAutoArrayPtr usage, let's return a UniquePtr from
the function directly.
Looking at a preference file read with strace typically looks like:
open("...", O_RDONLY) = X
...
read(X, "...", SIZE) = SIZE
read(X, "...", SIZE) = 0
...
There's no reason to call Read() and make another syscall to determine
there's no data left for reading. We can keep track of how much we've
read at minimal cost and thus determine for ourselves when we are done.
Calling nsIInputStream::Available on nsIFileInputStreams is relatively
expensive, as it requires three system calls: one to determine the
current file position, one to seek to the end file position, and one to
rewind to the previous file position.
We can do better by asking the file for its size directly, prior to
opening the stream. This only requires one system call, stat, and is
thus superior--at least in considering the number of system calls.
The bulk of this commit was generated with a script, executed at the top
level of a typical source code checkout. The only non-machine-generated
part was modifying MFBT's moz.build to reflect the new naming.
CLOSED TREE makes big refactorings like this a piece of cake.
# The main substitution.
find . -name '*.cpp' -o -name '*.cc' -o -name '*.h' -o -name '*.mm' -o -name '*.idl'| \
xargs perl -p -i -e '
s/nsRefPtr\.h/RefPtr\.h/g; # handle includes
s/nsRefPtr ?</RefPtr</g; # handle declarations and variables
'
# Handle a special friend declaration in gfx/layers/AtomicRefCountedWithFinalize.h.
perl -p -i -e 's/::nsRefPtr;/::RefPtr;/' gfx/layers/AtomicRefCountedWithFinalize.h
# Handle nsRefPtr.h itself, a couple places that define constructors
# from nsRefPtr, and code generators specially. We do this here, rather
# than indiscriminantly s/nsRefPtr/RefPtr/, because that would rename
# things like nsRefPtrHashtable.
perl -p -i -e 's/nsRefPtr/RefPtr/g' \
mfbt/nsRefPtr.h \
xpcom/glue/nsCOMPtr.h \
xpcom/base/OwningNonNull.h \
ipc/ipdl/ipdl/lower.py \
ipc/ipdl/ipdl/builtin.py \
dom/bindings/Codegen.py \
python/lldbutils/lldbutils/utils.py
# In our indiscriminate substitution above, we renamed
# nsRefPtrGetterAddRefs, the class behind getter_AddRefs. Fix that up.
find . -name '*.cpp' -o -name '*.h' -o -name '*.idl' | \
xargs perl -p -i -e 's/nsRefPtrGetterAddRefs/RefPtrGetterAddRefs/g'
if [ -d .git ]; then
git mv mfbt/nsRefPtr.h mfbt/RefPtr.h
else
hg mv mfbt/nsRefPtr.h mfbt/RefPtr.h
fi
After this change, we have ShallowSizeOf{In,Ex}cludingThis(), which don't do
anything to measure children. (They can be combined with iteration to measure
children.)
After this change, we have PLDHashTable::ShallowSizeOf{In,Ex}cludingThis(),
which don't do anything to measure children. (They can be combined with
iteration to measure children.)
This patch also removes the PL_DHashTableSizeOf{In,Ex}cludingThis() functions.
They're not necessary because the methods can be used instead.
Finally, the patch deliberately converts some SizeOfExcludingThis() calls to
SizeOfIncludingThis(). These are all done on heap pointers so this change is
valid.
This makes it clearer that, unlike how SizeOf*() functions usually work, this
doesn't measure any children hanging off the array.
And do likewise for nsTObserverArray.
The bulk of this commit was generated by running:
run-clang-tidy.py \
-checks='-*,llvm-namespace-comment' \
-header-filter=^/.../mozilla-central/.* \
-fix
They are kept around for the sake of the standalone glue, which is used
for e.g. webapprt, which doesn't have direct access to jemalloc, and thus
still needs a wrapper to go through the xpcom function list and get to
jemalloc from there.
