GPU resources have been designed with locking by fences in mind, fences were treated as implicit locks on a GPU, design paradigms such as `GraphicsContext` simply unlocking the texture mutex after attaching it which would set the fence cycle were considered fine prior but are unoptimal as it enforces that a `FenceCycle` effectively ensures exclusivity. This conflates the function of a mutex which is mutual exclusion and that of the fence which is to track GPU-side completion and led to tying if it was acceptable to use a GPU resource to GPU completion rather than simply if it was not currently being used by the CPU which is the function of the mutex.
This rework fixes this with the groundwork that has been laid with previous commits, as `Context` semantics are utilized to move back to using mutexes for locking of resources and tracking the usage on the GPU in a cleaner way rather than arbitrary fence comparisons. This also leads to cleaning up a lot of methods that involved usage of fences that no longer require it and therefore can be entirely removed, further cleaning up the codebase. It also opens the door for future improvements such as the removal of `hostImmutableCycle` and replacing them with better solutions, the implementation of which is broken at the moment regardless.
While moving to `Context`-based locking the question of multiple GPU workloads being in-flight while using overlapping resources came up which brought a fundamental limitation of `FenceCycle` to light which was that only one resource could be concurrently attached to a cycle and it could not adequately represent multi-cycle dependencies. `FenceCycle` chaining was designed to fix this inadequacy and allows for several different GPU workloads to be in-flight concurrently while utilizing the same resources as long as they can ensure GPU-GPU synchronization.
If we want to allow submitting multiple pieces of work to the GPU at once while still requiring CPU synchronization, we'll need to track all past fence cycles associated with a resource alongside the current one. To solve this the concept of chaining fences has been introduced, fences from past usages can be chained to the latest fence which'll then recursively forward operations to chained fences.
This change also ends up mandating a move away from `FenceCycleDependency` as it would prevent fences from concurrently locking the same resources which is required for chaining to work as two fences being chained fundamentally means they're locking the same resources. The `AtomicForwardList` is therefore used as the new container.
An implementation of a singly-linked list with atomic access to allow for lock-free access semantics, it eliminates the requirement for a mutex which can introduce additional consideration for synchronization.
Resources on the GPU can be fairly convoluted and involve overlaps which can lead to the same GPU resources being utilized with different views, we previously utilized fences to lock resources to prevent concurrent access but this was overly harsh as it would block usage of resources till GPU completion of the commands associated with a resource.
Fences have now been replaced with locks but locks run into the issue of being per-view and therefore to add a common object for tracking usage the concept of "tags" was introduced to track a single context so locks can be skipped if they're from the same context. This is important to prevent a deadlock when locking a resource which has been already locked from the current context with a different view.
We do not want to allow saving of user data on unsigned builds as they don't have a stable signature and will not properly handle reinstallation. This can lead to a situation where the user has to resort to complex techniques to completely uninstall the package such as ADB or calling into PM directly.
We currently present all frames synchronously on the thread that calls into SurfaceFlinger functions, this is unoptimal as it doesn't match guest behavior which can lead to delaying the guest from working on the next frame. This commit queuing up frames to non-blocking and handles all waiting then presenting the frame on a dedicated thread.
We utilize `pthread_setname_np` to set the thread names but didn't check for any errors which resulted in the `Skyline-Choreographer` and `ChannelCmdFifo` not having proper names as they exceeded the 16 character limit on thread names for the pthread function. This has now been fixed by changing the names and introducing error checking to invocations of this function.
All our normal alignment functions are designed to only handle power of 2 (`POT`) multiples as we only align or check alignment to `POT` multiples but there are cases where this is not possible and we deal with `NPOT` multiples which is why this function is required.
We waited on the host GPU after `Execute` but this isn't optimal as it causes a major stall on the CPU which can lead to several adverse effects such as downclocking by the governor and losing the opportunity to work in parallel with the GPU.
This has now been fixed by splitting `Execute`'s functionality into two functions: `Submit` and `SubmitWithFlush` which both execute all nodes and submit the resulting command buffer to the GPU but flushing will wait on the GPU to complete while the non-flush variant will not wait and work ahead of the GPU.
We need move-assignment semantics to viably utilize these objects as class members, they cannot be replaced without move-assign (or copy-assign but that is undesirable here). This commit fixes that by introducing a move assignment operator to them while making the `slot` a pointer which has the necessary nullability semantics.
This change lets items get the updated position of their view holder in the adapter. Fixes an issue where the position of items was not updated after being removed from a `SelectableGenericAdapter`.
This preference launches `GpuDriverActivity` for managing custom gpu drivers. When the device has an incompatible GPU, the preference will be disabled and greyed out.
The activity adds the following functionalities:
* Lists installed drivers
* Allows the user to install new drivers, or remove installed ones
* Allows the user to select the driver that will be used by the emulator
At some point we will call Submit within draws or constant buffer updates, to avoid any infinite recursion mark draw/cbuf pending as false before performing any operation
The previous name was chosen as an afterthought and didn't clearly indicate what the purpose of the class is. We needed a separate, simple class without delegates members (like PreferenceSettings), so that its fields can be easily accessed via JNI to get settings values from native code.
The `Settings` class now has a pure virtual `Update` method, and uses inheritance over template specialization for platform-specific behavior override.
A `Setting` delegate class has been introduced, holding the raw value of the setting and adding support for registering callbacks to that setting. Callbacks will then be called when the value of that setting changes.
As a result of this, raw setting values have been made accessible through pointer dereference semantics.
SharedPreferences will be partially swapped out in the future to support per-game settings. In the meantime, make it clear from which class settings are coming from.
Settings are now shared to the native side by passing an instance of the Kotlin's `Settings` class. This way the C++ `Settings` class doesn't need to parse the SharedPreferences xml anymore.
Mali GPU drivers utilize the `ppoll()` syscall inside `waitForFences` which isn't correctly restarted after a signal, which we can receive at any time on a guest thread. This commit fixes that by recursively calling the function on failure till it succeeds or returns an unexpected error.
Co-authored-by: PixelyIon <pixelyion@protonmail.com>
Co-authored-by: Billy Laws <blaws05@gmail.com>
These applets are used by applications to display a custom error message to the user. Both the error message and the detailed error message are printed to the error log.
Co-authored-by: lynxnb <niccolo.betto@gmail.com>
This conforms to the C++ 'Allocator' named requirement allowing it to be used with any STL type and allows drastically reducing allocation times in cases which are suited for linear allocation.
