This regression was introduced in https://github.com/flutter/engine/pull/21820
for sound-null safety. The settings used to launch the VM were incorrectly used
to determine the isolate lifecycle callbacks. Since the first shell/engine in
the process also starts the VM, these objects are usually identical. However,
for subsequent engine shell/engine launches, the callbacks attached to the new
settings object would be ignored. The unit-test harness is also structured in
such a way that each test case tears down the VM before the next. So all
existing tests created a bespoke VM for the test run, and, the tests that did
create multiple isolates did not also test attaching callbacks to the settings
object.
Fixes https://github.com/flutter/engine/pull/22041
Snapshots compiled with sound null-safety enabled require changes to the way in
which isolates are launched. Specifically, the `Dart_IsolateFlags::null_safety`
field needs to be known upfront. The value of this field can only be determined
once the kernel snapshot is available. This poses a problem in the engine
because the engine used to launch the isolate at shell initialization and only
need the kernel mappings later at isolate launch (when transitioning the root
isolate to the `DartIsolate::Phase::Running` phase). This patch delays launch of
the isolate on the UI task runner till a kernel mapping is available. The side
effects of this delay (callers no longer having access to the non-running
isolate handle) have been addressed in this patch. The DartIsolate API has also
been amended to hide the method that could return a non-running isolate to the
caller. Instead, it has been replaced with a method that requires a valid
isolate configuration that returns a running root isolate. The isolate will be
launched by asking the isolate configuration for its null-safety
characteristics.
A side effect of enabling null-safety is that Dart APIs that work with legacy
types will now terminate the process if used with an isolate that has sound
null-safety enabled. These APIs may no longer be used in the engine. This
primarily affects the Dart Convertors in Tonic that convert certain C++ objects
into the Dart counterparts. All known Dart Converters have been updated to
convert C++ objects to non-nullable Dart types inferred using type traits of the
corresponding C++ object. The few spots in the engine that used the old Dart
APIs directly have been manually updated. To ensure that no usage of the legacy
APIs remain in the engine (as these would cause runtime process terminations),
the legacy APIs were prefixed with the `DART_LEGACY_API` macro and the macro
defined to `[[deprecated]]` in all engine translation units. While the engine
now primarily works with non-nullable Dart types, callers can still use
`Dart_TypeToNonNullableType` to acquire nullable types for use directly or with
Tonic. One use case that is not addressed with the Tonic Dart Convertors is the
creation of non-nullable lists of nullable types. This hasn’t come up so far in
the engine.
A minor related change is reworking tonic to define a single library target.
This allows the various tonic subsystems to depend on one another. Primarily,
this is used to make the Dart convertors use the logging utilities. This now
allows errors to be more descriptive as the presence of error handles is caught
(and logged) earlier.
Fixes https://github.com/flutter/flutter/issues/59879
This removes most of the remaining FLUTTER_NOLINT comments and opts
these files back into linter enforcement.
I've filed https://github.com/flutter/flutter/issues/68273 to require
that all FLUTTER_NOLINT comments be followed by a GitHub issue URL
describing the problem to be fixed.
* Revert "Fix documentation build for window changes. (#21780)"
This reverts commit 931a04683d6eb49fc92059b2384ac5b1618d5422.
* Revert "Migration to PlatformDispatcher and multi-window (#20496)"
This reverts commit 85b0031f73544e448354047dc6a236c0b0808252.
This reverts commit 5585ed99039efb3705025e1c58170cdb86af111b.
Additionally, the following _flutter.runInView deadlock is fixed.
Previously, a deadlock would occur when service protocol
_flutter.runInView is used to restart the engine wihtout tearing down
the shell: the shared mutex of the service protocol will be locked
during the restart as it's in the middle of handling a service protocol
message; if ServiceProtocol::AddHandler is also called during the
restart, the deadlock happens as AddHandler also requires such lock.
test/integration.shard/background_isolate_test.dart would fail
without this fix.
This is a PR for converting the dart:ui code in the engine to use a multi-window API. The goal here is to convert from the window singleton to an API that has the concept of multiple windows. Also, I'm matching up the new PlatformDispatcher class to talk directly to the PlatformConfiguration class in the engine. I'm not attempting to actually enable creating multiple windows here, just migrate to an API that has a concept of multiple windows. The multi-window API in this PR currently only ever creates one window.
The design doc for this change is here.
The major changes in this PR:
Move the platfom-specific attributes out of Window, and into the new PlatformDispatcher class that holds all of the platform state, so that the platform code need only update the configuration on this class.
Create FlutterView, FlutterWindow, and SingletonFlutterWindow classes to separate out the concepts of a view (of which there may be multiple in a window), a window (of which there may be multiple on a screen, and they host views), and a window where there is only ever expected to be one (this hosts the entire API of the former Window class, and will eventually be the type of the window singleton).
Next step after this PR lands:
Remove the Window class entirely (it is replaced by SingletonFlutterWindow). Some minor changes in the Framework are needed to switch to using SingletonFlutterWindow directly first.
The Window class still exists in this PR, but will be removed as soon as the framework is converted to point to the SingletonFlutterWindow class instead. They share the same API, just have different names (Window is currently a subclass of SingletonFlutterWindow). The intention is that the Window name will be freed up to use as a widget class name in the framework for managing windows. The singleton called window will remain, and keep the same API it has now.
Follow up from #21436 . That PR works for all embeddings except for Android, which creates a special JNI AssetResolver. Since the shell cannot recreate this resolver, update the logic to preserve existing resolvers instead.
Embedders can now notify shell during startup about the various displays and their corresponding settings.
Adds a notion of Display update type which can later include chages to displays during runtime such as addition / removal / reconfiguration of displays.
We also remove the responsibility of providing the refresh rate from `vsync_waiter` to `DisplayManager`.
Rewires existing platform implementations of the said API to use `Shell::OnDisplayUpdate` to notify the display manager of the startup configuration.
DisplayManager is also thread-safe to account for rasterizer and UI thread accesses.
This will allow customers to try out the lightweight isolate support in the Dart VM in AOT mode.
To be future proof, we also add the negative flags to the allow list, thereby allowing the Dart VM to
change the default in the future, while still allowing customers to opt out.
Issue b/158554251
Cleans up header order/grouping for consistency: associated header, C/C++ system/standard library headers, library headers, platform-specific #includes.
Adds <cstring> where strlen, memcpy are being used: there are a bunch of places we use them transitively.
Applies linter-required cleanups. Disables linter on one file due to included RapidJson header. See https://github.com/flutter/flutter/issues/65676
This patch does not cover flutter/shell/platform/darwin. There's a separate, slightly more intensive cleanup for those in progress.
We currently use a mix of C standard includes (e.g. limits.h) and their
C++ variants (e.g. climits). This migrates to a consistent style for all
cases where the C++ variants are acceptable, but leaves the C
equivalents in place where they are required, such as in the embedder
API and other headers that may be used from C.
The directory may be invalid when running shell_unittests because
some tests call SetCacheDirectoryPath and then delete the directory.
Later tests that try to use that cache base path will be unable to
open the directory.
Add copyright headers in a few files where they were missing.
Trim trailing blank comment line where present, for consistency with
other engine code.
Use the standard libtxt copyright header in one file where it differed
(extra (C) and comma compared to other files in libtxt).
This also amends tools/const_finder/test/const_finder_test.dart to look
for a const an additional four lines down to account for the copyright
header added to the test fixture.
Fixes https://github.com/flutter/flutter/issues/65258
The following devicelab tests should pass after this patch:
- flutter_gallery_sksl_warmup__transition_perf_e2e_ios32
- flutter_gallery_sksl_warmup_ios32__transition_perf
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
## Description
As the related issue refer, the application may be doing too much work on its main thread even in a simple hello_world demo.
That is because the creation of `Engine` on the ui thread takes a noticeable time, and it is blocking the platform thread in order to run `Shell::Setup` synchronously.
The cost of `Engine`'s constructor is mainly about the creating of root isolate. Actually, there used to be another time-consuming process, the default font manager setup, which was resolved by https://github.com/flutter/engine/pull/18225.
Similar to https://github.com/flutter/engine/pull/18225, this pr move the creation of root isolate out from creating `Engine`. After this action, the main thread blocking is quite an acceptable slice.
## Related Issues
https://github.com/flutter/flutter/issues/40563 could be resolved by this pr.
