Now that everything is forcibly linker initialized, it feels like a
good time to get rid of the `init`/`initLinkerInitialized` split.
This allows to get rid of various `memset` construct in `init` that
gcc complains about (this fixes a Fuchsia open issue).
I added various `DCHECK`s to ensure that we would get a zero-inited
object when entering `init`, which required ensuring that
`unmapTestOnly` leaves the object in a good state (tests are currently
the only location where an allocator can be "de-initialized").
Running the tests with `--gtest_repeat=` showed no issue.
Differential Revision: https://reviews.llvm.org/D103119
Summary:
Most of our larger data is dynamically allocated (via `map`) but it
became an hindrance with regard to init time, for a cost to benefit
ratio that is not great. So change the `TSD`s, `RegionInfo`, `ByteMap`
to be static.
Additionally, for reclaiming, we used mapped & unmapped a buffer each
time, which is costly. It turns out that we can have a static buffer,
and that there isn't much contention on it.
One of the other things changed here, is that we hard set the number
of TSDs on Android to the maximum number, as there could be a
situation where cores are put to sleep and we could miss some.
Subscribers: mgorny, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D74696
The class is only used in SizeClassAllocator32 in 64-bit mode, but we don't
use that class in 64-bit mode.
Differential Revision: https://reviews.llvm.org/D74099
Summary:
fork() wasn't well (or at all) supported in Scudo. This materialized
in deadlocks in children.
In order to properly support fork, we will lock the allocator pre-fork
and unlock it post-fork in parent and child. This is done via a
`pthread_atfork` call installing the necessary handlers.
A couple of things suck here: this function allocates - so this has to
be done post initialization as our init path is not reentrance, and it
doesn't allow for an extra pointer - so we can't pass the allocator we
are currently working with.
In order to work around this, I added a post-init template parameter
that gets executed once the allocator is initialized for the current
thread. Its job for the C wrappers is to install the atfork handlers.
I reorganized a bit the impacted area and added some tests, courtesy
of cferris@ that were deadlocking prior to this fix.
Subscribers: jfb, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D72470
Summary:
We ran into a problem on Fuchsia where yielding threads would never
be deboosted, ultimately resulting in several threads spinning on the
same TSD, and no possibility for another thread to be scheduled,
dead-locking the process.
While this was fixed in Zircon, this lead to discussions about if
spinning without a break condition was a good decision, and settled on
a new hybrid model that would spin for a while then block.
Currently we are using a number of iterations for spinning that is
mostly arbitrary (based on sanitizer_common values), but this can
be tuned in the future.
Since we are touching `common.h`, we also use this change as a vehicle
for an Android optimization (the page size is fixed in Bionic, so use
a fixed value too).
Reviewers: morehouse, hctim, eugenis, dvyukov, vitalybuka
Reviewed By: hctim
Subscribers: srhines, delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D64358
llvm-svn: 365790
Summary:
The more tests are added, the more we are limited by the size of the
address space on 32-bit. Implement `unmapTestOnly` all around (like it
is in sanitzer_common) to be able to free up some memory.
This is not intended to be a proper "destructor" for an allocator, but
allows us to not fail due to having no memory left.
Reviewers: morehouse, vitalybuka, eugenis, hctim
Reviewed By: morehouse
Subscribers: delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D63146
llvm-svn: 363095
Summary:
The bytemap classes will be used by the primary32 allocator to associate
classes with memory regions. It's similar to the sanitizer_common one
except for the fact that the base (level1) maps are mapped instead of
being static to reduce the memory footprint of an uninitialized allocator.
Reviewers: vitalybuka, eugenis, morehouse, flowerhack, dmmoore415, mcgrathr
Reviewed By: vitalybuka, morehouse
Subscribers: mgorny, delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D58723
llvm-svn: 355416
Kostya Kortchinsky