That NDK bug has been fixed since r8c, and we now require something more
recent than that. This effectively reverts the changes from bug 720621
and bug 734832.
They are both infallible wrappers of posix_memalign and valloc.
There is also moz_xmemalign, which wraps memalign, which is mostly
always available as of bug 1402647.
None of them are actually used, but it's still desirable to at least
have one infallible variant, so keep moz_xmemalign and remove the other
two.
While here, we actually make both memalign and moz_xmemalign always
available.
They are both infallible wrappers of posix_memalign and valloc.
There is also moz_xmemalign, which wraps memalign, which is always
available as of bug 1402647.
None of them are actually used, but it's still desirable to at least
have one infallible variant, so keep moz_xmemalign and remove the other
two.
While here, we actually make moz_xmemalign always available, since
memalign is always available.
So far, logalloc has avoided logging calls that e.g. return null
pointers, but both to make the code more generic and to enable logging
of error conditions, we now log every call.
While jemalloc_stats is not actively doing anything, it can be
cumbersome to not have it count as an operation, because the operation
count shown on jemalloc_stats doesn't match the line number in the input
replay log, and the offset grows as the number of jemalloc_stats
operations grows.
While here, also update a comment about the replay log format.
It adds an uncompressible and noticeable time overhead to replaying
logs, even when one is not interested in measuring RSS. This has caused
me to clear the method body on multiple occasions.
If necessary, it is possible to enable zero or junk at the allocator
level for the same effect.
And statically link logalloc.
Statically linking is the default, except when building with
--enable-project=memory, allowing to use the generated libraries from
such builds with Firefox.
This makes things slightly more inconvenient (having to set two
environment variables instead of one for the simplest case) until a few
patches down the line, when DMD is statically linked, at which point it
will get down to one environment variable every time.
Now that replace_init can opt-out of registering the replace-malloc
functions, don't do so when MALLOC_LOG was not set in the environment.
While one would normally set MALLOC_LOG alongside one of the environment
variable necessary to load the replace-malloc library, we're also going,
in a subsequent change, to allow statically linking replace-malloc
libraries, taking full advantage of this change.
As of bug 1420353, DMD's replace_* functions can't be called before
replace_init places them in the malloc function table, which only
happens after DMD::Init has run, meaning DMD is always initialized
by the time any of its replace_* function can be called.
The original purpose of those declarations was to avoid the function
definitions being wrong, as well as forcing them being exported
properly (as extern "C", as weak symbols when necessary, etc.), but:
- The implementations being C++, function overloads simply allowed
functions with the same name to have a different signature.
- As of bug 1420353, the functions don't need to be exported anymore,
nor do we care whether their symbols are mangled. Furthermore, they're
now being assigned to function table fields, meaning there is type
checking in place, now.
So all in all, these declarations can be removed.
Also, as further down the line we're going to statically link the
replace-malloc libraries, avoid symbol conflicts by making those
functions static.
And statically link logalloc.
Statically linking is the default, except when building with
--enable-project=memory, allowing to use the generated libraries from
such builds with Firefox.
This makes things slightly more inconvenient (having to set two
environment variables instead of one for the simplest case) until a few
patches down the line, when DMD is statically linked, at which point it
will get down to one environment variable every time.
Now that replace_init can opt-out of registering the replace-malloc
functions, don't do so when MALLOC_LOG was not set in the environment.
While one would normally set MALLOC_LOG alongside one of the environment
variable necessary to load the replace-malloc library, we're also going,
in a subsequent change, to allow statically linking replace-malloc
libraries, taking full advantage of this change.
As of bug 1420353, DMD's replace_* functions can't be called before
replace_init places them in the malloc function table, which only
happens after DMD::Init has run, meaning DMD is always initialized
by the time any of its replace_* function can be called.
The original purpose of those declarations was to avoid the function
definitions being wrong, as well as forcing them being exported
properly (as extern "C", as weak symbols when necessary, etc.), but:
- The implementations being C++, function overloads simply allowed
functions with the same name to have a different signature.
- As of bug 1420353, the functions don't need to be exported anymore,
nor do we care whether their symbols are mangled. Furthermore, they're
now being assigned to function table fields, meaning there is type
checking in place, now.
So all in all, these declarations can be removed.
Also, as further down the line we're going to statically link the
replace-malloc libraries, avoid symbol conflicts by making those
functions static.
Because one entry point is simpler than two, we make replace_init fulfil
both the roles of replace_init and replace_get_bridge.
Note this should be binary compatible with older replace-malloc
libraries, albeit not detecting their bridge (and with the
previous change, they do not register anyways). So loading older
replace-malloc libraries should do nothing, but not crash in awful ways.
The allocator API is a moving target, and every time we change it, the
surface for replace-malloc libraries grows. This causes some build
system problems, because of the tricks in replace_malloc.mk, which
require the full list of symbols.
Considering the above and the goal of moving some of the replace-malloc
libraries into mozglue, it becomes simpler to reduce the replace-malloc
exposure to the initialization functions.
So instead of the allocator poking into replace-malloc libraries for all
the functions, we expect their replace_init function to alter the table
of allocator functions it's passed to register its own functions.
This means replace-malloc implementations now need to copy the original
table, which is not a bad thing, as it allows function calls with one
level of indirection less. It also replace_init functions to not
actually register the replace-malloc functions in some cases, which will
be useful when linking some replace-malloc libraries into mozglue.
Note this is binary compatible with previously built replace-malloc
libraries, but because those libraries wouldn't update the function
table, they would stay disabled.
SRWLock is more lightweight than CriticalSection, but is only available
on Windows Vista and more. So until we actually dropped support Windows
XP, we had to use CriticalSection.
Now that all supported Windows versions do have SRWLock, this is a
switch we can make, and not only because SRWLock is more lightweight,
but because it can be statically initialized like on other platforms,
allowing to use the same initialization code as on other platforms,
and removing the requirement for a DllMain, which in turn can allow
to statically link mozjemalloc in some cases, instead of requiring a
shared library (DllMain only works on shared libraries), or manually
call the initialization function soon enough.
There is a downside, though: SRWLock, as opposed to CriticalSection, is
not fair, meaning it can have thread scheduling implications, and can
theoretically increase latency on some threads. However, it is the
default used by Rust Mutex, meaning it's at least good enough there.
Let's see how things go with this.
This will make allocation operations return nullptr in the face of OOM,
allowing callers to either handle the allocation error or for the normal
OOM machinery, which also records the requested size, to kick in.
It is one of the moving parts when adding new memory allocation APIs.
It was added in bug 1168719 and the only thing that actually used it
was the sampling-based memory profiler, which was removed in bug
1385953. We however keep the replace-malloc bridge entry point so that
something else, in the future, may still provide the feature.
Those macros are one more thing that needs to be added when the
mozjemalloc API surface is increased, but after bug 1399350, nothing
actually needs them, so remove them.
