* utils: add LRU cache to RefCountedMap
This change introduces a new data structure LruCache and uses it in
RefCountedMap to keep a fixed number of cache entries alive after their
reference count has dropped to zero in the main map.
* utils: address LRU cache comments
* Automatically flush CommandStream
When generating commands, we now automatically flush the CommandStream,
so that we're guaranteed to not overrun the circular buffer.
* clenaup CircularBuffer implementation and API
Also fix a bug in DEBUG mode that could corrupt the CircularBuffer, it
was due to a wrong debugging code attempting to clear the unused
area of the buffer (this was wrong because in "ashmem" mode, there are
no guaranteed unused areas).
* Fix a couple threading vs. allocations
- prepareVisibleLights was run on a dedicated thread (via JobSystem),
but was using its own local ArenaScope. This is wrong because it
could reset the root arena at any later point. This is fixed by
just not using a local ArenaScope.
- related to the above, the root Arena (LinearAllocatorArena) didn't
use a locked policy, which cause also cause problems since some
allocations are done off the main thread. We now pre-allocate the one
buffer we need.
This PR also renames some variable and types to improve readability.
* Rework RenderPass to improve allocations and API
RenderPass now is a fully immutable object that gets constructed with a
RenderPassBuilder. RenderPassBuilder can be passed around and doesn't
do any (major) allocations.
All RenderPass allocations and heavy lifting is done in
RenderPassBuilder::Build().
Additionally, RenderPass cannot be copied anymore.
Where allocations happen is now much clearer.
* new LinearAllocatorWithFallback
LinearAllocatorWithFallback is a linear allocator that can fall back
to the heap allocator. We use it for the high level command buffer to
avoid crashing when running out of memory.
FIXES=[277115740]
* Update filament/src/RenderPass.h
Co-authored-by: Powei Feng <powei@google.com>
* Update libs/utils/include/utils/Allocator.h
Co-authored-by: Powei Feng <powei@google.com>
---------
Co-authored-by: Powei Feng <powei@google.com>
__ANDROID__ is always set by the toolchain and less likely to cause
conflicts than ANDROID. This change also removes the -DANDROID flag
we set ourselves in our toolchain CMake files since we don't need
it anymore.
TrackingPolicy::Debug didn't store the base pointer of the Area, and
instead relied on the first allocation to discover it, however, because
of alignment, the first allocation may not match the base pointer.
Because of that there could be an overflow in onRewind(), i.e. we
could rewind to a pointer before the (wrongly computed) base. This
overflow caused the debug memset to go awry and stomped on memory.
This is fixed by passing the base pointer to the constructor of the
TrackingPolicy. This base pointer could be nullptr with certain
allocators, but in that case, onReset/onRewind should never be called;
and this is enforced at compile time.
Also fixed a (luckily) harmless buffer overflow when preparing the
dynamic lights, if the number of lights wasn't a multiple of 4. This
was harmless because we use a linear allocator, so overflows are not
really overflows.
This can be enabled by using the Tracking::Debug policy,
currently this just fills allocation on alloc() and free(),
which is useful to help detect access to uninitialized memory
and use after free.
Now enabled by default in libfilament allocators on debug builds.
This caught uninitialized access in the froxelizer.
* Minor clean-ups
- fix a couple usage of std::function
- fix a couple usage of std::string
- remove ALIGN_LOOP, which didn't work
- fix a couple explicit/noexcept
- virtual -> override
* Fix spelling typos and other minor clang-tidy
* Fix a reuse after free in the job system
Jobs were destroyed and recycled while still in use
by wait() or run(). To fix this we introduce reference-counting of
jobs.
Jobs start with a ref-count of 1, which is decremented when a job
naturally finishes. Additionally, all user-facing methods acquire
a reference for the duration of the call.
* Fix an API inconsistency with JobSystem
JobSystem's API lets the user create jobs but not destroy them.
Jobs are destroyed automatically, without a way for the caller to
know when that happens.
We now explicitly enforce that jobs are no longer valid when
wait() returns. Multiple concurrent wait() are allowed however.
This is enforced by clearing the job pointer upon returning
from JobSystem::wait(Job* job).
* Rename linked-list put/get to push/pop
* Better fix for Job use after free
There was still a race condition where a run()'ed
job could be destroyed before wait() was called,
wait would then use a destroyed object.
The available APIs now are:
run() - runs and destroys a job
runAndWait() - run, then waits for and destroys a job
runAndRetain() - runs and keep a reference to the job
wait() - waits and destroys a job
wait() can only be used with a job obtained with runAndRetain().
* Get rid of unused code
This version of parallel_for has use-after-free issues anyways,
since we changed the semantics of run/wait/etc...
* Fix decRef() memory order
decRef() must ensure that all access to the
object have happened before destroying it.
* Fix memory order in atomic linked list's pop()
It needs acquire semantic, since we want to make
sure that no read/write are reordered before the
pop() -- which returns an object to the caller.
* Fix memory order on runningJobCount
we needed acquire semantic when about to destroy
the last job -- it's similar to decRef.
* Comment usages of std::memory_order_*
* Fix AtomicFreeList A-B-A bug
Turns out AtomicFreeList was not immune to the ABA bug. W're fixing
it here by using a 64-bits CAS, which is available on aarch64 and armv7.
* JobSystem now automatically free Jobs
Until now Job allocation used a linear allocator
strategy which required to “reset” the JobSystem
periodically — typically once per frame in
filament.
This is no longer required. We use a pool allocator
now, which doesn’t add much overhead. It does
use a spin-lock for thread-safety though, since
we assume very little contention, this shouldn’t
be a problem.
* Thread Safe Object Pool Allocator
A lock-less, thread-safe object pool allocator,
now used for storing JobSystem’s jobs allocations.
This gets rid of the spin-lock introduced in the
previous cl.
