Lazy async stacks were already enabled by-default in AOT mode in [0] - which made the
gen_snapshot invocations use "--lazy-async-stacks --no-causal-async-stacks".
This change does the same with the engine defaults, which makes this be enabled
by-default in JIT mode as well.
See go/dart-10x-faster-async for more information.
This is a re-land: A fix for what we believe to have caused the last revert has landed upstream in Dart in dart-lang/sdk@0004589
[0] flutter/flutter@3478232
This change reverts https://github.com/flutter/engine/pull/15900. The
design of the expected consumer of the original PR changed, and the
feature ended up going unused. Since the unexpected difference in trace
event routing behavior has mostly ended up as a source of confusion,
change things back to route trace events to Fuchsia system tracing on
all configurations.
The engine was using a global to store a timestamp representing the
launch of the engine. This timestamp is initialized with a JNI call
on Android and during shell setup on other platforms. Later the
timestamp is added to a FlutterEngineMainEnter timeline event used to
measure engine startup time in benchmarks.
This PR removes the global and the JNI call and moves the timestamp
into the settings object.
This was already enabled by-default in AOT mode in [0] - which made the
gen_snapshot invocations use "--lazy-async-stacks --no-causal-async-stacks".
See go/dart-10x-faster-async for more information.
[0] https://github.com/flutter/flutter/commit/347823234fd
`FlutterEnginePostCallbackOnAllNativeThreads` schedule a callback to be run on
all engine managed threads. The engine will attempt to service this callback the
next time the message loops for each managed thread is idle. Since the engine
manages the entire lifecycle of multiple threads, there is no opportunity for
the embedders to finely tune the priorities of threads directly, or, perform
other thread specific configuration (for example, setting thread names for
tracing). This callback gives embedders a chance to affect such tuning.
Fixesflutter/flutter#49551
Fixes b/143774406
Fixes b/148278215
Fixes b/148278931
* Revert "Revert "Provide dart vm initalize isolate callback so that children isolates belong to parent's isolate group. (#9888)" (#12327)"
* Ensure that when isolate shuts down it calls isolate_data, rather than isolage_group_data callback.
Remove dead shared snapshot arguments to Dart_CreateIsolateGroup.
6a65ea9cad4b [vm] Remove shared snapshot and reused instructions features.
db8370e36147 [gardening] Fix frontend-server dartdevc windows test.
4601bd7bffea Modified supertype check error message to be more descriptive.
0449905e2de6 [CFE] Add a serialization-and-unserialization step to strong test
c8b903c2f94f Update CHANGELOG.md
2a12a13d9684 [Test] Skips emit_aot_size_info_flag_test on crossword.
b26127fe01a5 [cfe] Add reachability test skeleton
* Provide dart vm initalize isolate callback so that children isolates belong to parent's isolate group.
Without this callback each child isolate is created as a separate isolate group, and Dart VM won't be able to provide performance savings for spawning of those.
This patch reworks image decompression and collection in the following ways
because of misbehavior in the described edge cases.
The current flow for realizing a texture on the GPU from a blob of compressed
bytes is to first pass it to the IO thread for image decompression and then
upload to the GPU. The handle to the texture on the GPU is then passed back to
the UI thread so that it can be included in subsequent layer trees for
rendering. The GPU contexts on the Render & IO threads are in the same
sharegroup so the texture ends up being visible to the Render Thread context
during rendering. This works fine and does not block the UI thread. All
references to the image are owned on UI thread by Dart objects. When the final
reference to the image is dropped, the texture cannot be collected on the UI
thread (because it has not GPU context). Instead, it must be passed to either
the GPU or IO threads. The GPU thread is usually in the middle of a frame
workload so we redirect the same to the IO thread for eventual collection. While
texture collections are usually (comparatively) fast, texture decompression and
upload are slow (order of magnitude of frame intervals).
For application that end up creating (by not necessarily using) numerous large
textures in straight-line execution, it could be the case that texture
collection tasks are pending on the IO task runner after all the image
decompressions (and upload) are done. Put simply, the collection of the first
image could be waiting for the decompression and upload of the last image in the
queue.
This is exacerbated by two other hacks added to workaround unrelated issues.
* First, creating a codec with a single image frame immediately kicks of
decompression and upload of that frame image (even if the frame was never
request from the codec). This hack was added because we wanted to get rid of
the compressed image allocation ASAP. The expectation was codecs would only be
created with the sole purpose of getting the decompressed image bytes.
However, for applications that only create codecs to get image sizes (but
never actually decompress the same), we would end up replacing the compressed
image allocation with a larger allocation (device resident no less) for no
obvious use. This issue is particularly insidious when you consider that the
codec is usually asked for the native image size first before the frame is
requested at a smaller size (usually using a new codec with same data but new
targetsize). This would cause the creation of a whole extra texture (at 1:1)
when the caller was trying to “optimize” for memory use by requesting a
texture of a smaller size.
* Second, all image collections we delayed in by the unref queue by 250ms
because of observations that the calling thread (the UI thread) was being
descheduled unnecessarily when a task with a timeout of zero was posted from
the same (recall that a task has to be posted to the IO thread for the
collection of that texture). 250ms is multiple frame intervals worth of
potentially unnecessary textures.
The net result of these issues is that we may end up creating textures when all
that the application needs is to ask it’s codec for details about the same (but
not necessarily access its bytes). Texture collection could also be delayed
behind other jobs to decompress the textures on the IO thread. Also, all texture
collections are delayed for an arbitrary amount of time.
These issues cause applications to be susceptible to OOM situations. These
situations manifest in various ways. Host memory exhaustion causes the usual OOM
issues. Device memory exhaustion seems to manifest in different ways on iOS and
Android. On Android, allocation of a new texture seems to be causing an
assertion (in the driver). On iOS, the call hangs (presumably waiting for
another thread to release textures which we won’t do because those tasks are
blocked behind the current task completing).
To address peak memory usage, the following changes have been made:
* Image decompression and upload/collection no longer happen on the same thread.
All image decompression will now be handled on a workqueue. The number of
worker threads in this workqueue is equal to the number of processors on the
device. These threads have a lower priority that either the UI or Render
threads. These workers are shared between all Flutter applications in the
process.
* Both the images and their codec now report the correct allocation size to Dart
for GC purposes. The Dart VM uses this to pick objects for collection. Earlier
the image allocation was assumed to 32bpp with no mipmapping overhead
reported. Now, the correct image size is reported and the mipmapping overhead
is accounted for. Image codec sizes were not reported to the VM earlier and
now are. Expect “External” VM allocations to be higher than previously
reported and the numbers in Observatory to line up more closely with actual
memory usage (device and host).
* Decoding images to a specific size used to decode to 1:1 before performing a
resize to the correct dimensions before texture upload. This has now been
reworked so that images are first decompressed to a smaller size supported
natively by the codec before final resizing to the requested target size. The
intermediate copy is now smaller and more promptly collected. Resizing also
happens on the workqueue worker.
* The drain interval of the unref queue is now sub-frame-interval. I am hesitant
to remove the delay entirely because I have not been able to instrument the
performance overhead of the same. That is next on my list. But now, multiple
frame intervals worth of textures no longer stick around.
The following issues have been addressed:
* https://github.com/flutter/flutter/issues/34070 Since this was the first usage
of the concurrent message loops, the number of idle wakes were determined to
be too high and this component has been rewritten to be simpler and not use
the existing task runner and MessageLoopImpl interface.
* Image decoding had no tests. The new `ui_unittests` harness has been added
that sets up a GPU test harness on the host using SwiftShader. Tests have been
added for image decompression, upload and resizing.
* The device memory exhaustion in this benchmark has been addressed. That
benchmark is still not viable for inclusion in any harness however because it
creates 9 million codecs in straight-line execution. Because these codecs are
destroyed in the microtask callbacks, these are referenced till those
callbacks are executed. So now, instead of device memory exhaustion, this will
lead to (slower) exhaustion of host memory. This is expected and working as
intended.
This patch only addresses peak memory use and makes collection of unused images
and textures more prompt. It does NOT address memory use by images referenced
strongly by the application or framework.
* Roll src/third_party/dart 67ab3be10d...43891316ca
dart-lang/sdk@/43891316ca [ VM / Observatory ] Emit IsolateReload event after reload completes
dart-lang/sdk@/2ea7e5513b Perform type promotion when NNBD, using flow analysis.
dart-lang/sdk@/766e542e53 handle return in async function
dart-lang/sdk@/51cf8f218a Add entension support to the summary idl
dart-lang/sdk@/0e9957c7b1 [dartdevc] Adding support for analyzer dep pruning
dart-lang/sdk@/c100308ba6 Repro for inferring arrays with out of range lengths
dart-lang/sdk@/5d77657e7a Prepare to publish analyzer version 0.37.0.
dart-lang/sdk@/86ce74caaa update NodeBuilder for default value type arguments
dart-lang/sdk@/439692c9e2 Mark the name in an extension as being in a declaration context
dart-lang/sdk@/372bcae536 [gardening] Fix 3xHEAD Flutter build after revert
dart-lang/sdk@/052874e93e Avoid non-web integer literal in corelib_2/int_round_test
dart-lang/sdk@/480337106e Implementation of extension override AST node
dart-lang/sdk@/4f78ad90df An initial and partial implementation of an element model for extensions
dart-lang/sdk@/744bb47361 [infra] Remove custom timeouts for dart2js compiler config
dart-lang/sdk@/9b53686ffb update NodeBuilder for declared identifier implicit type
dart-lang/sdk@/3d14b75f97 Revert "Reland "[vm/concurrency] Introduce concept of Isolate Groups""
dart-lang/sdk@/527238e008 [vm] Cleanup C99 header includes
dart-lang/sdk@/9f32f9b87e [cfe] Store the initializer tokens in constructor builders
dart-lang/sdk@/bbbeb8b509 Pull in latest pub
dart-lang/sdk@/851958ee54 update NodeBuilder to handle for loop
dart-lang/sdk@/7a73682c6a update NodeBuilder to handle catch clause
dart-lang/sdk@/fc6cb0ac21 [vm/ffi] Revamp struct representation in FFI.
dart-lang/sdk@/5fd51b9fd2 Cleanup remnants of ignoring Dart v1.x subtype checks
dart-lang/sdk@/45172f0690 Revert "Reland "[llvm] Add initial scaffolding""
dart-lang/sdk@/b9a6630367 [ Observatory ] _getVMTimeline -> getVMTimeline in timeline.js
dart-lang/sdk@/1f02c10b9a Update language_2/const_map4_test for type inference
dart-lang/sdk@/99ed4871b3 Fix a hint in analysis server
dart-lang/sdk@/c3c43689d5 [vm] Remove platform/math.h
dart-lang/sdk@/524fdc13a9 Reland "[llvm] Add initial scaffolding"
dart-lang/sdk@/45a9815aff [vm/debugger] break on asyncfunction entry
dart-lang/sdk@/e0eeffaf9b update NodeBuilder parameter tracking when visiting executable declarations
dart-lang/sdk@/182a59cebb Skip all tests that use spawnUri when running in simulator mode as it makes no sense to run the CFE on the simulator.
dart-lang/sdk@/1427a218f3 update DecoratedType asserts
dart-lang/sdk@/f4dc001729 Migration: begin adding support for LUB computations in conditional expressions.
dart-lang/sdk@/585794ab75 Fix status file line.
dart-lang/sdk@/4a69ef4a50 Skip all spawnURI tests for the simulator architectures as these tests involve invoking the front end for compilation which would mean the front end has to run in simulated mode.
dart-lang/sdk@/26f369eb8e Fix doc comment for NullabilityNode.forLUB
dart-lang/sdk@/9ed728ec7a Add: Example usage to fillRange method.
dart-lang/sdk@/fc7049ae7d Migration: implement support for user-definable prefix expressions.
dart-lang/sdk@/77aa5f0c02 Migration: Add support for function-typed formal parameters.
dart-lang/sdk@/326e970b81 Migration: handle method invocations that resolve to a getter.
dart-lang/sdk@/822de210b5 fix branch_canonicalization_test
dart-lang/sdk@/a2e1434603 Breaking changes for analyzer version 0.37
dart-lang/sdk@/6694aa821d [dart2js] new-rti: Temporary work-around for timeouts
dart-lang/sdk@/18ff5ce893 [dart2js] new-rti: Implement general As/Check methods
dart-lang/sdk@/90c88d984e Fix large integer literals in dart2js_extra/round_constant_folding_test
dart-lang/sdk@/9349f71721 bump linter to 0.1.93
dart-lang/sdk@/c384212f9e [vm] Remove vestigial verified_memory_test.cc file
dart-lang/sdk@/f4824d332d [vm] Drop support for MSVC older than 2013
dart-lang/sdk@/bbb027aa2a [vm] Fix offset that was breaking bare_instructions_trampolines_test
dart-lang/sdk@/1db0b4436c [dart2js] new-rti: Implement type bounds check
dart-lang/sdk@/686742585a Migration: add a more robust assertion to the DecoratedType constructor
dart-lang/sdk@/2fd4ca570b set DecoratedType.returnType for FunctionType
dart-lang/sdk@/ca4b6e533a [dart2js] new-rti: Implement basic is-test
dart-lang/sdk@/39b71253ce Fix for curly_braces_in_flow_control_structures lint.
dart-lang/sdk@/b6c3b2c98c Enable 'Surround with XYZ' only for Statement(s) in Block(s).
dart-lang/sdk@/79e478e50e Fixed some links
dart-lang/sdk@/279c1da42d Use absolute paths as canonical paths for inputs digest maps
dart-lang/sdk@/cbf9cff19f Infer types of field formals before all fields.
dart-lang/sdk@/0c6b3d1277 Migration: do better function type formatting in DecoratedType.toString.
dart-lang/sdk@/a76c459239 Migration: Remove unnecessary duplicate type test
dart-lang/sdk@/a515a0c256 Reland "[vm/ffi] SimDBC on Arm64 Android"
dart-lang/sdk@/0baf81e7d6 Tests for Never and potential nullable / non-nullable.
dart-lang/sdk@/26d308aad3 Use flow analysis for reporting use sites of not assigned locals during resolution.
dart-lang/sdk@/79f276e07d Migration: handle field formal parameters.
dart-lang/sdk@/c8c3572ca9 Migration: standardize method names in EdgeBuilderTest.
dart-lang/sdk@/c0c15c1283 Migration: build nullability node for default type parameter bounds directly.
dart-lang/sdk@/b57ff85906 Migration: clean up and test implicit dynamic return type of Function() syntax.
dart-lang/sdk@/0f2eda8644 Migration: add support for function expression invocations.
dart-lang/sdk@/a200980da0 Migration: add support for variable and field type inference.
dart-lang/sdk@/ca25f56883 Migration: add support for type inference of function types.
dart-lang/sdk@/a436c0621f Migration: fix DecoratedType.toString to support named function parameters.
dart-lang/sdk@/9dee307bdb Migration: update nullability graph debug dump to support union edges.
dart-lang/sdk@/b60dcdbf73 Migration: Remove the `create` parameter from Variables.decoratedElementType.
dart-lang/sdk@/18c21ee9d1 Migration: add support for generic instance creation.
dart-lang/sdk@/f7ddfdf6ca Migration: don't forget to visit variable initializers in NodeBuilder.
dart-lang/sdk@/a39e4fabfb Add information about the deprecated ParameterElement.parameterKind
dart-lang/sdk@/f6dfad02f4 [analyzer] add a space to the quick for for REPLACE_COLON_WITH_EQUALS
* Revert changes makde in the engine for the Isolate Group API change.
* Fix compilation error.
* Update license.
* Format.
This reverts commit 0fcfa0df2aa19947ad73882ab4fb24fc9124e47b.
Windows depends on referencing the snapshot symbols directly instead of
via dlsym. Something in the way these symbolsa are generated in
bin_to_assembly.py is causing them to be inaccessible at runtime.
Some components in the Flutter engine were derived from the forked blink codebase. While the forked components have either been removed or rewritten, the use of the blink namespace has mostly (and inconsistently) remained. This renames the blink namesapce to flutter for consistency. There are no functional changes in this patch.
