In some cases like presentation, it may be possible to avoid waiting on the CPU by using a semaphore to indicate GPU completion. Due to the binary nature of Vulkan semaphores this requires a fair bit of code as we need to ensure semaphores are always unsignalled before they are waited on and signalled again. This is achieved with a special kind of chained cycle that can be added even after guest GPFIFO processing for a given cycle, the main cycle's semaphore can be waited and then the cycle for the wait attached to the main cycle and it will be waited on before signalling.
TIC sizes may not be aligned to block linear dimensions whereas RT sizes are and then limited by the surface clip. By using this to determine surface size we are more likely to get a match in texture manager for any future usages.
Keep a copy of the old TIC entry and view even after purge caches and use the execution number to check validity instead, if that doesn't match then just memcmp can be used as opposed to a full hash and map lookup.
When profiling SMO, it became obvious that the constant locking of textures and buffers in SyncDescriptors took up a large amount of CPU time (3-5%), a precious resource in intensive areas like Metro. This commit implements somewhat of a workaround to avoid constant relocking, if a buffer is frequently attached on the GPU and almost never used on the CPU we can keep the lock held between executions. Of course it's not that simple though, if the guest tries to lock a texture for the first time which has already been locked as preserve on the GPFIFO we need to avoid a deadlock. This is acheived through a combination of two things: first we periodically clear the locked attachments every 2*SlotCount submissions, preventing a complete deadlock on the CPU (just a long wait instead) and meaning that the next time the resource is attached on the GPU it will not be marked for preservation due to having been locked on the guest before; second, we always need to unlock everything when the GPU thread runs out of work, as the perioding clearing will not execute in this case which would otherwise leave the textures locked on the GPFIFO thread forever (if guest was waiting on a lock to submit work). It should be noted that we don't clear preserve attached resources in the latter scenario, only unlock them and then relock when more work is available.
Avoids one race where we would end up hogging all the locks of chained cycles and ourself when waiting for submission of previous cycles and prevent any forward progress due to another thread locking one of the chained cycles.
For the upcoming preserve attachment optimisation, which will keep buffers/textures locked on the GPU between executions, we don't want to preserve any which are frequently locked on the CPU as that would result in lots of needless waiting for a resource to be unlocked by the GPU when it occasionally frees all preserve attachments when it could have been done much sooner. By checking if a resource has ever been locked on the CPU and using that to choose whether we preserve it we can avoid such waiting.
Allowing for parallel execution of channels never really benefitted many games and prevented optimisations such as keeping frequently used resources always locked to avoid the constant overhead of locking on the hot path.
Ontop of the TIC cache from previous code a simple index based lookup has been added which vastly speeds things up by avoding the need to hash the TIC structure every time.
Introducing async record resulted in breaking the assumption that any work submitted through command scheduler would be submitted in order with graphics submits. Since async record now unlocks the texture before it's submitted a seperate mechanism is needed to ensure ordering of submits. This is achieved by building support into fence cycle itself, with a conditional variable that is waited on for submission before any fence waits occur.
GPFIFO code is very high throughput due to the sheer number of commands used for rendering. Adjust some types and switch to a if statement with hints to slightly increase processing speed.
Recording of command nodes into Vulkan command buffers is very easily parallelisable as it can effectively be treated as part of the GPU execution, which is inherently async. By moving it to a seperate thread we can shave off about 20% of GPFIFO execution time. It should be noted that the command scheduler command buffer infra is no longer used, since we need to record texture updates on the GPFIFO thread (while another slot is being recorded on the record thread) and then use the same command buffer on the record thread later. This ends up requiring a pool per slot, which is reasonable considering we only have four slots by default.
Using command executor for each state individual update was found to be infeasible due to the shear number of state updates per draw and it relying on per-node heap allocations. Instead this commit takes advantage of each state update being used only once to implement a system of linearly-allocated state update commands that are linked together. After setting up all draw state with StateUpdateBuilder, the built StateUpdater can then be used in the execution phase to record all of the draw state into the command buffer with almost zero ovehead.
SMO implements instanced draws by repeating the same draw just with a different constant buffer bound. Reduce the cost of this significantly by detecting such cases and instead of processing every descriptor, copy the previous descriptor set and update only the ones affected by the bound constant buffer.
Credits to ripinperiperi for the initial idea and making me aware of how SMO does these draws
When a buffer is trapped nearly every frame, the cost of trapping and synchronising its contents starts to quickly add up. By always using the megabuffer when this is the case, since megabuffer copies are done directly from the guest, we skip the need to synchronise/trap the backing.
The original intention was to cache on the user side, but especially with shader constant buffers that's difficult and costly. Instead we can cache on the buffer side, with a page-table like structure to hold variable sized allocations indexed by the aligned view base address. This avoids most redundant copies from repeated use of the same buffer without updates inbetween.
Avoids the need to hash PipelineState when we can guess the pipeline that will be used next. This could very easily be optimised in the future with generational, usage-based caching if necessary.
gm20b performs instanced draws by repeating draw methods for each instance, the code to detect this together with the cost of interpreting macros took up around 6% of GPFIFO time in Metro Kingdom. By detecting these specific macros and performing an instanced draw directly much of that cost can be avoided.
gpu-new will use a monolithic pipeline object for each pipeline to store state, keyed by the PackedPipelineState contents. This allows for a greater level of per-pipeline optimisations and a reduction in the overall number of lookups in a draw compared to the previous system.
Caching here was deemed unnecessary since it will be done implicitly by the pipeline cache and creates issues with the legacy attribute conversion pass. It now purely serves as a frontend for Hades.
It was determined that a general purpose Vulkan pipeline cache isn't viable for the significant performance reqs of Draw(), by using a Maxwell 3D specific key we can shrink state significantly more than if we used Vulkan structs.
Removes all usage of graphics_context.h from the codebase, exclusively using the new interconnect and its dirty tracking system. While porting the code a number of bugs were discovered such as not respecting the base instance or primitive type override, which have all been fixed. Currently only clears and constant buffer updates are implemented but due to the dirty state system allowing register handling on the interconnect end there shouldn't end up being many more changes.
This mainly distributes operations down to activeState and pipelineState, aside from clears which are implemented in-place. The exposed interface is much reduced as opposed to the previous GraphicsContext system due to the newly introduced dirty system, this should hopefully make the code more maintainable and keep actual rendering operations seperate from primitive restart state or whatever. Currently draws are unimplemented and the only full implemented things are clears and constant buffer operations.
Active state encapsulates all state that isn't part of a pipeline and can be set dynamically with Vulkan calls. This includes both dynamic state like stencil faces, and command buffer state like vertex buffer bindings.
Simililarly to the last commit, the main goal of this is to reduce the number of redundant work done per draw by employing dirty state as much as possible. Without using dirty state for this every active state operation would need to be performed every draw, which gets very expensive when things like buffer lookups end up being reqiored. Code has also been heavily cleaned up as is described in the previous commit.
The main goal of this is to reduce the number of redundant lookups and work done per draw as much as possible, this is mainly achived through heavy used of dirty tracking though other optimisations like heavily using the linear allocator are also in play. In addition to the goal of performance, the code has been cleaned up and abstracted significantly from its state in graphics_context, hopefully making the GPU interconnect code much more maintainable in the future and reducing the boilerplace needed to add even simple functionality. This commit includes partial pipeline state, enough for implementing clears + a slight bit extra.
Adepted from the previous code to use dirty state tracking. The cache has also been removed since with the new buffer view and GMMU optimisations it actually ended up slowing lookups down, another result of the buffer view optimisations is that raw pointers are no longer used for buffer views since destruction is now much cheaper.
This common code will be used across the entirety of the 3D rewrite, it also includes a stub for StateUpdateBuilder, which will be used by active state code to apply state updates.
All the names are directly translated from Nvidia docs, with minimal conversions to enums/structs when appropriate. Not all registers have been rewritten, only those that are needed to implement clears and dynamic state, the rest will be added as they are used in the GPU rework.
This will be heavily used by the upcoming GPU rework. It provides an intuitive way to track dirtiness based on using the underlying pointers of objects, as opposed to other methods which often need an enum entry per dirty state and don't support overlaps. Wrappers for dirty state objects are also provided to abstract as much of the dirty tracking as possible from user code. The pointer based mechanism also serves to avoid having to handle dirty bindings on the user side of the dirty resources, allowing them to bind things internally instead.
Constant buffer updates result in a barrage of std::mutex calls that take a lot of time even under no contention (around 5%). Using a custom spinlock in cases like these allows inlining locking code reducing the cost of locks under no contention to almost 0.
This can be inlined by the compiler much easier which helps perf a fair bit due to the number of times buffers are looked up, also avoids the need for small vector construction that was done in the previous fast-path.
This isn't a guarantee provided by actual HW so we don't need to provide it either, the sync can be skipped once the buffer already been synced at least once within the execution.
Constructing the GPU copy callback in `ConstantBuffers::Load()` ended up taking a fair amount of time despite it almost never being used in practice. By making it optional it can be skipped most of the time and only done when it's actually neccessary by calling `Write()` again if the initial call returned true.
Buffer views creation was a significant pain point, requiring several layers of caching to reduce the number of creations that introduced a lot of complexity. By reworking delegates to be per-buffer rather than per-view and then linearly allocating delegates (without ever freeing) views can be reduced to just {delegatePtr, offset, size}, avoiding the need for any allocations or set operations in GetView. The one difficulty with this is the need to support buffer recreation, which is achived by allowing delegates to be chained - during recreation all source buffers have their delegates modified to point to the newly created buffer's delegate. Upon accessing a view with such a chained delegate the view will be modified to point directly to the end delegate with offset being updated accordingly, skipping the need to traverse the chain for future accesses.
In the upcoming GPU code each state member will hold a reference to its corresponding Maxwell 3D regs, this helper is needed to allow easy transformation from the the main 3D register struct into them.
Example:
```c++
struct Regs {
std::array<View, 10> viewRegs;
u32 enable;
} regs;
struct ViewState {
const View &view;
const u32 &enable;
size_t index;
};
std::array<ViewState, 10> viewStates{MergeInto<ViewState, 10>(regs.viewRegs, regs.enable, IncrementingT{})
```
Useful for cases where allocations are guaranteed to be unused by the time `Reset()` is called and calling `Free()` would be difficult or add extra performance cost due to how the allocation is used.
In some games performing the binary search in `TranslateRange()` ended up taking a fairly large (~8%) proportion of GPFIFO time. By using a segment table for O(1) lookups this is reduced to <2% for non-split mappings at the cost of slightly increased memory usage (2GiB in the absolute worse case but more like 50MiB in real world situations).
In addition to adapting `TranslateRange()` to use the segment table, a new function `LookupBlock()` for cases where only a single mapping would ever be looked up so the small_vector handling and fallback paths can be skipped and the entire lookup be inlined.
Forward this function to OpenSaveDataFileSystem for now. A proper implementation should wrap the underlying filesystem with nn::fs::ReadOnlyFileSystem.
We want to know when the `KProcess` is being killed and flushing log during it is important since it can often result in hangs due to joining not working correctly.
We currently don't wait on a slot to be freed if none are free, this worked prior to async presentation as GBP's slots wouldn't change their state until other commands were called but now slots can be held by the presentation engine. As a result, we now have to wait on the presentation engine to free up slots.
This commit also fixes the behavior of the `async` flag in `DequeueBuffer` as it was treated as a non-blocking flag but isn't supposed to do anything on HOS.
Needed for games such as AC:NH.
The `Auto` option automatically selects a region based on the currently selected system language.
Co-Authored-By: Timotej Leginus <35149140+timleg002@users.noreply.github.com>
As part of this commit, a new preference category for debug settings is being introduced. All future settings only relevant for debugging purposes will be put there. The category is hidden on release builds.
Host synchronization of a guest texture with a different guest format represents a valid use case where the host doesn't support the guest format and conversion to a host-compatible format must be performed. The issue is most evident on Mali GPUs, as they don't support BCn texture formats thus needing manual decoding before submission. It was disabled by mistake in a previous commit, this commit re-enables it.
Unindexed quad draws were broken when multiple draw calls were done on the same vertex buffer, with a non-zero `first` index.
Indexed quad draws also suffered from the same issue, but was never encountered in games.
This commit fixes both cases by accounting for the `first` drawn index when generating conversion index buffers.
TIPC is a much lighter layer ontop of the Horizon IPC system than CMIF and is used by SM in 12.0.0+. This implementation is slightly hacky since it doesn't really keep a seperation between the underlying kernel IPC stuff and userspace like CMIF/TIPC, this should be fixed eventually, probably together with an IPC dispatch rewrite to avoid the mess of frozen maps.
Tested with Hentai Uni, which now crashes needing 'ldr:ro'.
Tapping anything in titles that supported touch (such as Puyo Puyo Tetris or Sonic Mania) wouldn't work due to the first touch point never being removed from the screen, it is supposed to be removed after a 3 frame delay from the touch ending.
This commit introduces a mechanism to "time-out" touch points which counts down during the shared memory updates and removes them from the screen after a specified timeout duration.
Certain titles depend on HID LIFO entries being written out at a fixed frequency rather than on actual state change, not doing this can lead to applications freezing till the LIFO is filled up to maximum size, this behavior is seen in Super Mario Odyssey. In other cases such as Metroid Dread, the game can run into race conditions that would lead to crashes, these were worked around by smashing a button during loading prior.
This commit introduces a thread which sleeps and wakes up occasionally to write LIFO entries into HID shared memory at the desired frequencies. This alleviates any issues as it fills up the LIFO instantly and correctly emulates HID Shared Memory behavior expected by the guest.
Co-authored-by: Narr the Reg <juangerman-13@hotmail.com>
It was determined that deadlocks inside `KThread::UpdatePriorityInheritance` would not only arise from the first level of locking with `waitingOn->waiterMutex` but also the second level of locking with `nextThread->waiterMutex` which has now also been fixed to fallback when facing contention.
PR #1758 introduced a bug where the game list would be entirely loaded every time the app was opened. This commit addresses that issue, which was caused by the `version` member of the cached game list being serialized to file (although incorrectly) but never actually read back when deserializing.
* Remove `package` from manifest and from activity prefixes, gradle `namespace` will be used instead
* Removed deprecated `android.support.PARENT_ACTIVITY` metadata
entries
* Make `MainActivity` and `SettingsActivity` launched in `singleTop` mode to avoid unnecessary activity restarts while navigating the app
Using `__attribute__((packed))` doesn't work in new NDKs when a struct contains 128-bit integer members, likely because of a ndk/compiler bug. We now enclose the requiring structs in `#pragma pack` directives to tightly pack them.
Since the blit engine itself samples from pixel corners and the helper shader from pixel centres teh src coordinates need to be adjusted to avoid the helper shader wrapping round on the final column.
We previously missed the hades pass for attribute conversion leading to crashes when games would attempt to use such an attribute. The hades pass for this isn't a proper fix however as it modifies the IR directly and will break if any of the previous stages in the pipeline change. Enable it to allow for games using them to at least have a chance at working. In the long term the pass will be reworked on the hades side to avoid modifying the IR in a way that can't be undone.
This vertex state must only be present for the last pipeline stage that touches vertices, if it is present for other stages it could result in incorrect behaviour like performing TFB in the fragment shader or flipping device coordinates twice.
As the code was before, if we had a shader that was disabled and enabled again after without being invalidated the pipeline stage would stay disabled and break rendering.
We previously only supported non-indexed quads. Support for this is implemented by converting the index buffer at record time and pushing the result into the megabuffer, which is then used as the index buffer in the final draw command.
The `Allocate` method allocates the given amount of space in a megabuffer chunk, returning a descriptor of the allocated region. This is useful for situations where you want to write directly to the megabuffer, avoiding the need for an intermediary buffer.
Entirely rewrites the engine and interconnect code to take advantage of the subpixel and OOB blit support offered by the blit helper shader. The interconnect code is also cleaned up significantly with the 'context' naming being dropped due to potential conflicts with the 'context' from context lock
It is desirable for us to use a shader for blits to allow easily emulating out of bounds blits and blits between different swizzled colour formats. The helper shader infrastructure is designed to be generic so it can be reused by any other helper shaders that we may need in the future.
These sometimes spuriously occur in games during transitions, to avoid crashing during them just use the null texture if they occur and log an error log
The constant destruction and creation of `BufferView`s in cbuf-heavy games showed up as a large chunk of the profiler. Fix this by taking advantage of the fact that constant buffer `BufferView`s are never deleted and always kept around in the cache to just return a pointer to them in the cache.
Currently we heavily thrash the heap each draw, with malloc/free taking up about 10% of GPFIFOs execution time. Using a linear allocator for the main offenders of buffer usage callbacks and index/vertex state helps to reduce this to about 4%
Certain titles can have a display frames out of order due to not waiting on the copy from the final RT to the swapchain image to occur. Although `PresentFrame` does wait on the syncpoint, that isn't enough to ensure the source texture is up-to-date due to us signalling syncpoints early.
By waiting on the swapchain texture after the copy is submitted, we now implicitly wait on the source texture's cycle to be signalled thus waiting on the frame to be done which fixes the issue.
After the introduction of workahead a system to hold a single large megabuffer per submission was implemented, this worked fine for most cases however when many submissions were flight at the same time memory usage would increase dramatically due to the amount of megabuffers needed. Since only one megabuffer was allowed per execution, it forced the buffer to be fairly large in order to accomodate the upper-bound, even further increasing memory usage.
This commit implements a system to fix the memory usage issue described above by allowing multiple megabuffers to be allocated per execution, as well as reuse across executions. Allocations now go through a global allocator object which chooses which chunk to allocate into on a per-allocation scale, if all are in use by the GPU another chunk will be allocated, that can then be reused for future allocations too. This reduces Hollow Knight megabuffer memory usage by a factor 4 and SMO by even more.
Accesses to unset entries is now clearly defined as returning a 0'd out value, the prior behavior would be to optimize sets for border segments to use L2 atomicity when the specific segment had no L1 entries set. This would lead to any future lookups of offsets within the same L2 segment but a different L1 entry to incorrectly return an inaccurate value as the only prior guarantee was that lookups after setting a segment would return the same value as was set but lacked the guarantee for unset segments to also consistently return unset values.
This could lead to issues in practical usages such as the `BufferManager` lookups returning the existence of a `Buffer` at a location falsely even though the segment was never set to the value, this was problematic as raw pointers were utilized and bound checks would lead to a segmentation fault.
This commit fixes this issue by introducing this guarantee and refactoring the class accordingly, it also deletes the `Set` method for setting a single entry as the meaning is ambiguous and it's functionality was more akin to the past guarantee and no longer makes sense.
Co-authored-by: PixelyIon <pixelyion@protonmail.com>
We would always write all L1 entries that correspond to an L2 entry, even if setting an input range ended before that. This would effectively reduce the atomicity of the segment table to that of the L2 range and lead to breaking API guarantees by returning entirely wrong segment values for a lookup covering a region that was overwritten.
It was determined that `RangeTable` was too ambiguous of a name as it could be interpreted to be holding ranges rather than looking them up, to avoid confusion the terminology has been changed to `range` to `segment`. As "segment table" is more clear in describing that it is a table comprised of descriptors regarding segments and it avoids any overlaps with terminology concerning "pages" which would be overly specific for this data structure or the ambiguous "ranges".
The PI CAS in `MutexUnlock` ends up loading `basePriority` rather than `priority` which could lead to an infinite CAS loop when `basePriority` doesn't equal to `priority` and the `highestPriorityThread`'s priority is lower than `basePriority`.
It was determined that `Texture::SynchronizeGuest`'s `TextureBufferCopy` had races that were exposed by the introduction of the cycle waiter thread, the synchronization did not take place under a locked context so the texture could be mutated at any point in addition to the destructor not being run during `FenceCycle::Wait` due to `shouldDestroy` being `false`.
This commit fixes the issue by making `SynchronizeGuest` entirely blocking as all usages of the function required blocking semantics regardless so it would be pointless to retain its async nature while solving any races that may arise from it being async.
Co-authored-by: Billy Laws <blaws05@gmail.com>
Since we don't call `SynchronizeHost` on source buffers which are GPU dirty, their mirrors will be out of date. The backing contents of this source buffer's region in the new buffer will be incorrect. By copying from the backing directly, we can ensure that no writes are lost and that if the newly created buffer needs to turn GPU dirty during recreation no copies need to be done since the backing is as up to date as the mirror at a minimum.
The code is much simpler to reason about when reading the code as it doesn't require evaluating all the potential edge cases of trap handlers in different states. It should be noted that this should not change behavior in any meaningful way, at most it can prevent a minor race where the protection could be upgraded after being downgraded by the signal handler leading to a redundant trap.
Two issues exist with locking of `KThread::waiterMutex`:
* It was not always locked when accessing waiter members such as `waitThread`, `waitKey` and `waitTag` which would lead to a race that could end up in a deadlock or most notably a segfault inside `UpdatePriorityInheritance`
* There could be a deadlock from `UpdatePriorityInheritance` locking `waiterMutex` of a thread and waiting to get the owner's `waiterMutex` while on another thread `MutexUnlock` holds the owner's `waiterMutex` and waits on locking the `waiterMutex` held by `UpdatePriorityInheritance`
This commit fixes both issues by adding appropriate locking to all locations where waiter members are accessed in addition to adding a fallback mechanism inside `UpdatePriorityInheritance` that unlocks `waiterMutex` on contention to avoid a deadlock.
The condition for exiting the CAS loops is incorrect in several places which leads to additional loops, while this doesn't make the behavior incorrect it does lead to redundant iterations.
Co-authored-by: Billy Laws <blaws05@gmail.com>
A substantial amount of time would be spent on creation/destruction of `VkDescriptorSet` which scales on titles doing a substantial amount of draws with bindings, this leads to poor performance on those titles as the frametime is dragged down by performing these tasks while they repeatedly create descriptor sets of the same layouts.
This commit fixes it by pooling descriptor sets per-layout in a dynamically resizable pool and keeping them around rather than destroying them after usage which leads to the vast majority of cases not requiring a new descriptor set to even be created. It leads to significantly improved performance where it would otherwise be spent on redundant destruction/recreation or push descriptor updates which took a substantial amount of time themselves.
Additionally, the `BaseDescriptorSizes` were not kept up to date with all of the descriptor types, it led to no crashes on Adreno/Mali as they were purely used for size calculations on either driver but has been corrected to avoid any future issues.
A substantial amount of time is spent destroying dependencies for any threads waiting or polling `FenceCycle`s, this is not optimal as it blocks them from moving onto other tasks while destruction is a fundamentally async task and can be delayed.
This commit solves this by introducing a thread that is dedicated to waiting on every `FenceCycle` then signalling and destroying all dependencies which entirely fixes the issue of destruction blocking on more important threads.
Buffer lookups are a fairly expensive operation that we currently spend `O(log n)` on the simplest and most frequent case of which is a direct match, this is a very frequent operation where that may be insufficient. This commit optimizes that case to `O(1)` by utilizing a `RangeTable` at the cost of slightly higher insertion/deletion costs for setting ranges of values but these are minimal in frequency compared to lookups.
A data structure that can represent the same value for a range of addresses (pages) is required for fast lookup in certain cases. This commit implements a near optimal data structure for mass insertion and O(1) lookup of range-based data, this is achieved using the host MMU and implementing multiple levels of atomicity for the ranges.
It should be noted that the table is limited to two levels but can be extended to a variable amount of ranges in the future, it was determined that additional levels of ranges can be beneficial for performance depending on the specific use-case.
Adreno drivers have certain errata which leads to Vulkan Push Descriptors to be broken on them in certain cases which leads to a descriptor set update being swallowed. This has been worked around by disabling push descriptors on Adreno drivers, this may lead to reduced performance on certain titles which frequently bind new descriptors.
Any semaphore releases are implicit synchronization events that can be utilized by the guest to pick up that the GPU has executed till a certain point and therefore we must submit all prior work accordingly.
DMA copies utilized `SubmitWithFlush` instead of `Submit`, this is not required and incurs significant additional synchronization penalties which will no longer be required.
We want to avoid blocking on surface creation unless necessary, this commit doesn't wait on the creation of the surface as it default initializes the value which'll generally be `Identity` or the transformation of the previous surface if it was lost.
Co-authored-by: Billy Laws <blaws05@gmail.com>
The V-Sync `KEvent` would be used by the presentation thread prior to construction leading to dereferencing an invalid value, this has been fixed by changing the order of construction to move the construction of the presentation thread after the V-Sync event.
The `TrapRegions` function performed a page-out on any regions that were trapped as read-only, this wasn't optimal as it would tie them both into the same operation while Buffers/Textures require to protect then synchronize and page-out. The trap was being moved to after the synchronize to get around this limitation but that can cause a potential race due to certain writes being done after the synchronization but prior to the trap which would be lost. This commit fixes these issues by splitting paging out into `PageOutRegions` which can be called after `TrapRegions` by any API users.
Co-authored-by: Billy Laws <blaws05@gmail.com>
`NCE::TrapRegions` was a bit too overloaded as a method as it implicitly trapped which was unnecessary in all current usage cases, this has now been made more explicit by consolidating the functionality into `NCE::CreateTrap` which handles just creation of the trap and nothing past that, `RetrapRegions` has been renamed to `TrapRegions` and handles all trapping now.
Co-authored-by: Billy Laws <blaws05@gmail.com>
Similar to `Buffer`s, `Texture`s suffered from unoptimal behavior due to using atomics for `DirtyState` and had certain bugs with replacement of the variable at times where it shouldn't be possible which have now been fixed by moving to using a mutex instead of atomics. This commit also updates the API to more closely match what is expected of it now and removes any functions that weren't utilized such as `SynchronizeGuestWithBuffer`.
Having a single variable denoting the exact state of a buffer and the operations that could be performed on it was found to be too restrictive, it's now been expanded into an additional `BackingImmutability` variable but due to these two. We can no longer use atomics without significant additional complexity so all accesses to the state are now mediated through `stateMutex`, a mutex specifically designed for tracking the state.
While designing the system around `stateMutex` it was determined to be more efficient than atomics as it would enforce blocking far less than it would generally have been compared to if the regular atomic fallback of locking the main resource lock which is locked for significantly longer generally.
Co-authored-by: PixelyIon <pixelyion@protonmail.com>
As a performance sensitive part of code, the NCE Trapping API benefits from having tracing and it helps us better determine where guest code is spending its time for more targeted optimizations.
