Package apple.metalperformanceshaders

Class MPSNNGraph

  • All Implemented Interfaces:
    NSCoding, NSCopying, NSSecureCoding, NSObject
    public class MPSNNGraph
extends MPSKernel
implements NSCopying, NSSecureCoding
    MPSNNGraph Optimized representation of a graph of MPSNNImageNodes and MPSNNFilterNodes Once you have prepared a graph of MPSNNImageNodes and MPSNNFilterNodes (and if needed MPSNNStateNodes), you may initialize a MPSNNGraph using the MPSNNImageNode that you wish to appear as the result. The MPSNNGraph object will introspect the graph representation and determine which nodes are needed for inputs, and which nodes are produced as output state (if any). Nodes which are not needed to calculate the result image node are ignored. Some nodes may be internally concatenated with other nodes for better performance. Note: the MPSNNImageNode that you choose as the result node may be interior to a graph. This feature is provided as a means to examine intermediate computations in the full graph for debugging purposes. During MPSNNGraph construction, the graph attached to the result node will be parsed and reduced to an optimized representation. This representation may be saved using the NSSecureCoding protocol for later recall. When decoding a MPSNNGraph using a NSCoder, it will be created against the system default MTLDevice. If you would like to set the MTLDevice, your NSCoder should conform to the protocol. You may find it helpful to set MPSKernelOptionsVerbose on the graph when debugging. To turn this on during MPSKernel initialization (including MPSNNGraph initialization) set the MPS_LOG_INFO environment variable. There is a lot of information about what optimizations are done to your graph, including some information on why certain optimizations were not made.

    • Constructor Detail

      • MPSNNGraph

        protected MPSNNGraph​(org.moe.natj.general.Pointer peer)

    • Method Detail

      • accessInstanceVariablesDirectly

        public static boolean accessInstanceVariablesDirectly()

      • allocWithZone

        public static java.lang.Object allocWithZone​(org.moe.natj.general.ptr.VoidPtr zone)

      • automaticallyNotifiesObserversForKey

        public static boolean automaticallyNotifiesObserversForKey​(java.lang.String key)

      • cancelPreviousPerformRequestsWithTarget

        public static void cancelPreviousPerformRequestsWithTarget​(java.lang.Object aTarget)

      • cancelPreviousPerformRequestsWithTargetSelectorObject

        public static void cancelPreviousPerformRequestsWithTargetSelectorObject​(java.lang.Object aTarget,
                                                                         org.moe.natj.objc.SEL aSelector,
                                                                         java.lang.Object anArgument)

      • classFallbacksForKeyedArchiver

        public static NSArray<java.lang.String> classFallbacksForKeyedArchiver()

      • classForKeyedUnarchiver

        public static org.moe.natj.objc.Class classForKeyedUnarchiver()

      • debugDescription_static

        public static java.lang.String debugDescription_static()

      • description_static

        public static java.lang.String description_static()

      • destinationImageAllocator

        public MPSImageAllocator destinationImageAllocator()
        Method to allocate the result image from -encodeToCommandBuffer... This property overrides the allocator for the final result image in the graph. Default: MPSImage.defaultAllocator

      • encodeToCommandBufferSourceImages

        public MPSImage encodeToCommandBufferSourceImages​(MTLCommandBuffer commandBuffer,
                                                  NSArray<? extends MPSImage> sourceImages)
        Encode the graph to a MTLCommandBuffer IMPORTANT: Please use [MTLCommandBuffer addCompletedHandler:] to determine when this work is done. Use CPU time that would have been spent waiting for the GPU to encode the next command buffer and commit it too. That way, the work for the next command buffer is ready to go the moment the GPU is done. This will keep the GPU busy and running at top speed. Those who ignore this advice and use [MTLCommandBuffer waitUntilCompleted] instead will likely cause their code to slow down by a factor of two or more. The CPU clock spins down while it waits for the GPU. When the GPU completes, the CPU runs slowly for a while until it spins up. The GPU has to wait for the CPU to encode more work (at low clock), giving it plenty of time to spin its own clock down. In typical CNN graph usage, neither may ever reach maximum clock frequency, causing slow down far beyond what otherwise would be expected from simple failure to schedule CPU and GPU work concurrently. Regrattably, it is probable that every performance benchmark you see on the net will be based on [MTLCommandBuffer waitUntilCompleted].
        Parameters:
        commandBuffer - The command buffer. If the command buffer is a MPSCommandBuffer, the work will be committed to Metal in small pieces so that the CPU-side latency is much reduced.
        sourceImages - A list of MPSImages to use as the source images for the graph. These should be in the same order as the list returned from MPSNNGraph.sourceImageHandles.
        Returns:
        A MPSImage or MPSTemporaryImage allocated per the destinationImageAllocator containing the output of the graph. It will be automatically released when commandBuffer completes. It can be nil if resultImageIsNeeded == NO

      • encodeToCommandBufferSourceImagesSourceStatesIntermediateImagesDestinationStates

        public MPSImage encodeToCommandBufferSourceImagesSourceStatesIntermediateImagesDestinationStates​(MTLCommandBuffer commandBuffer,
                                                                                                 NSArray<? extends MPSImage> sourceImages,
                                                                                                 NSArray<? extends MPSState> sourceStates,
                                                                                                 NSMutableArray<MPSImage> intermediateImages,
                                                                                                 NSMutableArray<MPSState> destinationStates)
        Encode the graph to a MTLCommandBuffer
        Parameters:
        commandBuffer - The command buffer. If the command buffer is a MPSCommandBuffer, the work will be committed to Metal in small pieces so that the CPU-side latency is much reduced.
        sourceImages - A list of MPSImages to use as the source images for the graph. These should be in the same order as the list returned from MPSNNGraph.sourceImageHandles. The images may be image arrays. Typically, this is only one or two images such as a .JPG decoded into a MPSImage*. If the sourceImages are MPSTemporaryImages, the graph will decrement the readCount by 1, even if the graph actually reads an image multiple times.
        sourceStates - A list of MPSState objects to use as state for a graph. These should be in the same order as the list returned from MPSNNGraph.sourceStateHandles. May be nil, if there is no source state. If the sourceStates are temporary, the graph will decrement the readCount by 1, even if the graph actually reads the state multiple times.
        intermediateImages - An optional NSMutableArray to receive any MPSImage objects exported as part of its operation. These are only the images that were tagged with MPSNNImageNode.exportFromGraph = YES. The identity of the states is given by -resultStateHandles. If temporary, each intermediateImage will have a readCount of 1. If the result was tagged exportFromGraph = YES, it will be here too, with a readCount of 2. To be able to access the images from outside the graph on the CPU, your application must also set MPSNNImageNode.synchronizeResource = YES, and MPSNNImageNode.imageAllocator = [MPSImage defaultAllocator]; The defaultAllocator creates a permanent image that can be read with readBytes.
        destinationStates - An optional NSMutableArray to receive any MPSState objects created as part of its operation. The identity of the states is given by -resultStateHandles.
        Returns:
        A MPSImage or MPSTemporaryImage allocated per the destinationImageAllocator containing the output of the graph. It will be automatically released when commandBuffer completes.

      • executeAsyncWithSourceImagesCompletionHandler

        public MPSImage executeAsyncWithSourceImagesCompletionHandler​(NSArray<? extends MPSImage> sourceImages,
                                                              MPSNNGraph.Block_executeAsyncWithSourceImagesCompletionHandler handler)
        Convenience method to execute a graph without having to manage many Metal details This function will synchronously encode the graph on a private command buffer, commit it to a MPS internal command queue and return. The GPU will start working. When the GPU is done, the completion handler will be called. You should use the intervening time to encode other work for execution on the GPU, so that the GPU stays busy and doesn't clock down. The work will be performed on the MTLDevice that hosts the source images. This is a convenience API. There are a few situations it does not handle optimally. These may be better handled using [encodeToCommandBuffer:sourceImages:]. Specifically: [@code] o If the graph needs to be run multiple times for different images, it would be better to encode the graph multiple times on the same command buffer using [encodeToCommandBuffer:sourceImages:] This will allow the multiple graphs to share memory for intermediate storage, dramatically reducing memory usage. o If preprocessing or post-processing of the MPSImage is required, such as resizing or normalization outside of a convolution, it would be better to encode those things on the same command buffer. Memory may be saved here too for intermediate storage. (MPSTemporaryImage lifetime does not span multiple command buffers.) [@endcode]
        Parameters:
        sourceImages - A list of MPSImages to use as the source images for the graph. These should be in the same order as the list returned from MPSNNGraph.sourceImageHandles. They should be allocated against the same MTLDevice. There must be at least one source image. Note: this array is intended to handle the case where multiple input images are required to generate a single graph result. That is, the graph itself has multiple inputs. If you need to execute the graph multiple times, then call this API multiple times, or (faster) make use of MPSImageBatches using -executeBatchToCommandBuffer:sourceImages:sourceStates:... (See discussion)
        handler - A block to receive any errors generated. This block may run on any thread and may be called before this method returns. The image, if any, passed to this callback is the same image as that returned from the left hand side.
        Returns:
        A MPSImage to receive the result. The data in the image will not be valid until the completionHandler is called.

      • hash_static

        public static long hash_static()

      • initWithCoderDevice

        public MPSNNGraph initWithCoderDevice​(NSCoder aDecoder,
                                      java.lang.Object device)
        NSSecureCoding compatability While the standard NSSecureCoding/NSCoding method -initWithCoder: should work, since the file can't know which device your data is allocated on, we have to guess and may guess incorrectly. To avoid that problem, use initWithCoder:device instead.
        Overrides:
        initWithCoderDevice in class MPSKernel
        Parameters:
        aDecoder - The NSCoder subclass with your serialized MPSKernel
        device - The MTLDevice on which to make the MPSKernel
        Returns:
        A new MPSKernel object, or nil if failure.

      • initWithDevice

        public MPSNNGraph initWithDevice​(java.lang.Object device)
        Description copied from class: MPSKernel
        Standard init with default properties per filter type
        Overrides:
        initWithDevice in class MPSKernel
        Parameters:
        device - The device that the filter will be used on. May not be NULL.
        Returns:
        a pointer to the newly initialized object. This will fail, returning nil if the device is not supported. Devices must be MTLFeatureSet_iOS_GPUFamily2_v1 or later.

      • instanceMethodSignatureForSelector

        public static NSMethodSignature instanceMethodSignatureForSelector​(org.moe.natj.objc.SEL aSelector)

      • instancesRespondToSelector

        public static boolean instancesRespondToSelector​(org.moe.natj.objc.SEL aSelector)

      • intermediateImageHandles

        public NSArray<?> intermediateImageHandles()
        Get a list of identifiers for intermediate images objects produced by the graph

      • isSubclassOfClass

        public static boolean isSubclassOfClass​(org.moe.natj.objc.Class aClass)

      • keyPathsForValuesAffectingValueForKey

        public static NSSet<java.lang.String> keyPathsForValuesAffectingValueForKey​(java.lang.String key)

      • new_objc

        public static java.lang.Object new_objc()

      • outputStateIsTemporary

        public boolean outputStateIsTemporary()
        Should MPSState objects produced by -encodeToCommandBuffer... be temporary objects. See MPSState description. Default: NO

      • resolveClassMethod

        public static boolean resolveClassMethod​(org.moe.natj.objc.SEL sel)

      • resolveInstanceMethod

        public static boolean resolveInstanceMethod​(org.moe.natj.objc.SEL sel)

      • resultHandle

        public MPSHandle resultHandle()
        Get a handle for the graph result image

      • resultStateHandles

        public NSArray<?> resultStateHandles()
        Get a list of identifiers for result state objects produced by the graph Not guaranteed to be in the same order as sourceStateHandles

      • setDestinationImageAllocator

        public void setDestinationImageAllocator​(MPSImageAllocator value)
        Method to allocate the result image from -encodeToCommandBuffer... This property overrides the allocator for the final result image in the graph. Default: MPSImage.defaultAllocator

      • setOutputStateIsTemporary

        public void setOutputStateIsTemporary​(boolean value)
        Should MPSState objects produced by -encodeToCommandBuffer... be temporary objects. See MPSState description. Default: NO

      • setVersion_static

        public static void setVersion_static​(long aVersion)

      • sourceImageHandles

        public NSArray<?> sourceImageHandles()
        Get a list of identifiers for source images needed to calculate the result image

      • sourceStateHandles

        public NSArray<?> sourceStateHandles()
        Get a list of identifiers for source state objects needed to calculate the result image Not guaranteed to be in the same order as resultStateHandles

      • superclass_static

        public static org.moe.natj.objc.Class superclass_static()

      • supportsSecureCoding

        public static boolean supportsSecureCoding()

      • _supportsSecureCoding

        public boolean _supportsSecureCoding()
        Description copied from interface: NSSecureCoding
        This property must return YES on all classes that allow secure coding. Subclasses of classes that adopt NSSecureCoding and override initWithCoder: must also override this method and return YES. The Secure Coding Guide should be consulted when writing methods that decode data.
        Specified by:
        _supportsSecureCoding in interface NSSecureCoding
        Overrides:
        _supportsSecureCoding in class MPSKernel

      • version_static

        public static long version_static()

      • format

        public long format()
        The default storage format used for graph intermediate images This doesn't affect how data is stored in buffers in states. Nor does it affect the storage format for weights such as convolution weights stored by individual filters. Default: MPSImageFeatureChannelFormatFloat16

      • graphWithDeviceResultImageResultImageIsNeeded

        public static MPSNNGraph graphWithDeviceResultImageResultImageIsNeeded​(MTLDevice device,
                                                                       MPSNNImageNode resultImage,
                                                                       boolean resultIsNeeded)

      • graphWithDeviceResultImagesResultsAreNeeded

        public static MPSNNGraph graphWithDeviceResultImagesResultsAreNeeded​(MTLDevice device,
                                                                     NSArray<? extends MPSNNImageNode> resultImages,
                                                                     org.moe.natj.general.ptr.BoolPtr areResultsNeeded)

      • initWithDeviceResultImageResultImageIsNeeded

        public MPSNNGraph initWithDeviceResultImageResultImageIsNeeded​(MTLDevice device,
                                                               MPSNNImageNode resultImage,
                                                               boolean resultIsNeeded)
        Initialize a MPSNNGraph object on a device starting with resultImage working backward The MPSNNGraph constructor will start with the indicated result image, and look to see what MPSNNFilterNode produced it, then look to its dependencies and so forth to reveal the subsection of the graph necessary to compute the image.
        Parameters:
        device - The MTLDevice on which to run the graph
        resultImage - The MPSNNImageNode corresponding to the last image in the graph. This is the image that will be returned. Note: the imageAllocator for this node is ignored and the MPSNNGraph.destinationImageAllocator is used for this node instead.
        resultIsNeeded - Commonly, when training a graph, the last MPSImage out of the graph is not used. The final gradient filter is run solely to update some weights. If resultIsNeeded is set to NO, nil will be returned from the left hand side of the -encode call instead, and computation to produce the last image may be pruned away.
        Returns:
        A new MPSNNGraph.

      • initWithDeviceResultImagesResultsAreNeeded

        public MPSNNGraph initWithDeviceResultImagesResultsAreNeeded​(MTLDevice device,
                                                             NSArray<? extends MPSNNImageNode> resultImages,
                                                             org.moe.natj.general.ptr.BoolPtr areResultsNeeded)
        Initialize a MPSNNGraph object on a device starting with resultImage working backward The MPSNNGraph constructor will start with the indicated result images, and look to see what MPSNNFilterNode produced them, then look to its dependencies and so forth to reveal the subsection of the graph necessary to compute the image. This variant is provided to support graphs and subgraphs with multiple image outputs.
        Parameters:
        device - The MTLDevice on which to run the graph
        resultImages - The MPSNNImageNodes corresponding to the last images in the graph. The first image in the array will be returned from the -encode method LHS. The rest will be included in the list of intermediate images.
        areResultsNeeded - An array of BOOL values with count equal to resultImages.count. If NO is passed for a given image, the image itself is marked unneeded and might be skipped. The graph will prune this branch back to the first requred filter. A filter is required if it generates a needed result image, or is needed to update training parameters.
        Returns:
        A new MPSNNGraph.

      • readCountForSourceImageAtIndex

        public long readCountForSourceImageAtIndex​(long index)
        Find the number of times a image will be read by the graph * From the set of images (or image batches) passed in to the graph, find the number of times the graph will read an image. This may be needed by your application to correctly set the MPSImage.readCount property.
        Parameters:
        index - The index of the image. The index of the image matches the index of the image in the array returned by the sourceImageHandles property.
        Returns:
        The read count of the image(s) at the index will be reduced by the value returned when the graph is finished encoding. The readcount of the image(s) must be at least this value when it is passed into the -encode... method.

      • readCountForSourceStateAtIndex

        public long readCountForSourceStateAtIndex​(long index)
        Find the number of times a state will be read by the graph * From the set of state (or state batches) passed in to the graph, find the number of times the graph will read a state. This may be needed by your application to correctly set the MPSState.readCount property.
        Parameters:
        index - The index of the state. The index of the state matches the index of the state in the array returned by the sourceStateHandles property.
        Returns:
        The read count of the state(s) at the index will be reduced by the value returned when the graph is finished encoding. The read count of the state(s) must be at least this value when it is passed into the -encode... method.

      • reloadFromDataSources

        public void reloadFromDataSources()
        Reinitialize all graph nodes from data sources A number of the nodes that make up a graph have a data source associated with them, for example a MPSCNNConvolutionDataSource or a MPSCNNBatchNormalizationDataSource. Generally, the data is read from these once at graph initialization time and then not looked at again, except during the weight / parameter update phase of the corresponding gradient nodes and then only if CPU updates are requested. Otherwise, update occurs on the GPU, and the data in the data source is thereafter ignored. It can happen, though, that your application has determined the graph should load a new set of weights from the data source. When this method is called, the graph will find all nodes that support reloading and direct them to reinitialize themselves based on their data source. This process occurs immediately. Your application will need to make sure any GPU work being done by the graph is complete to ensure data coherency. Most nodes do not have a data source and will not be modified. Nodes that are not used by the graph will not be updated.

      • resultImageIsNeeded

        public boolean resultImageIsNeeded()
        Set at -init time. If NO, nil will be returned from -encode calls and some computation may be omitted.

      • setFormat

        public void setFormat​(long value)
        The default storage format used for graph intermediate images This doesn't affect how data is stored in buffers in states. Nor does it affect the storage format for weights such as convolution weights stored by individual filters. Default: MPSImageFeatureChannelFormatFloat16