d8390d3f38
We now have one mutex guarding all accesses to the underlying task heaps. This simplifies the more granular but bug prone mechanism of having striped locks. This also re-enables GPUThreadMerger tests that are currently disabled due to their flaky nature. The scenario that gets fixed by this change is as follows: 1. Thread-1: We lock `queue_meta_mutex_` and grab locks on `queue_1` and release the meta mutex. 2. Thread-1: We add an Observer on `queues` object. 3. Thread-2: We lock `queue_meta_mutex_` and grab locks on `queue_2`. 4. Thread-2: We try to dispose all the pending tasks on `queue_2` which calls `erase` on `queues`. The above situation is not thread safe without having 1 lock. Note: This increases the contention on one lock and could potentially be bad for perf. We are explicitly making this trade-off towards reducing the complexity. Fixes: https://github.com/flutter/flutter/issues/49007
Flutter Engine
Flutter is Google's mobile app SDK for crafting high-quality native interfaces in record time. Flutter works with existing code, is used by developers and organizations around the world, and is free and open source.
The Flutter Engine is a portable runtime for hosting Flutter applications. It implements Flutter's core libraries, including animation and graphics, file and network I/O, accessibility support, plugin architecture, and a Dart runtime and compile toolchain. Most developers will interact with Flutter via the Flutter Framework, which provides a modern, reactive framework, and a rich set of platform, layout and foundation widgets.
If you are new to Flutter, then you will find more general information on the Flutter project, including tutorials and samples, on our Web site at Flutter.dev. For specific information about Flutter's APIs, consider our API reference which can be found at the docs.flutter.dev.
Flutter is a fully open source project, and we welcome contributions. Information on how to get started can be found at our contributor guide.