1 /*
  2  * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.  Oracle designates this
  8  * particular file as subject to the "Classpath" exception as provided
  9  * by Oracle in the LICENSE file that accompanied this code.
 10  *
 11  * This code is distributed in the hope that it will be useful, but WITHOUT
 12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 14  * version 2 for more details (a copy is included in the LICENSE file that
 15  * accompanied this code).
 16  *
 17  * You should have received a copy of the GNU General Public License version
 18  * 2 along with this work; if not, write to the Free Software Foundation,
 19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 20  *
 21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 22  * or visit www.oracle.com if you need additional information or have any
 23  * questions.
 24  */
 25 package hat;
 26 
 27 
 28 import hat.backend.Backend;
 29 import hat.buffer.Buffer;
 30 import hat.buffer.BufferAllocator;
 31 import hat.buffer.BufferTracker;
 32 import hat.ifacemapper.BoundSchema;
 33 import hat.ifacemapper.SegmentMapper;
 34 import hat.optools.OpTk;
 35 
 36 import java.lang.invoke.MethodHandles;
 37 import java.lang.reflect.Method;
 38 
 39 import jdk.incubator.code.Op;
 40 import jdk.incubator.code.Quotable;
 41 import jdk.incubator.code.Quoted;
 42 import jdk.incubator.code.dialect.java.JavaOp;
 43 
 44 import java.util.HashMap;
 45 import java.util.Map;
 46 import java.util.ServiceLoader;
 47 import java.util.function.Consumer;
 48 import java.util.function.Predicate;
 49 
 50 import static hat.backend.Backend.FIRST;
 51 
 52 
 53 /**
 54  * This class provides the developer facing view of HAT, and wraps a <a href="backend/Backend.html">Backend</a> capable of
 55  * executing <b>NDRange</b> style execution.
 56  * <p/>
 57  * An Accelerator is provided a <a href="java/lang/invoke/MethodHandles.Lookup.html">MethodHandles.Lookup</a> with visibility to the
 58  * compute to be performed.
 59  * <p/>
 60  * As well we either a <a href="backend/Backend.html">Backend</a> directly
 61  * <pre>
 62  * Accelerator accelerator =
 63  *    new Accelerator(MethodHandles.lookup(),
 64  *       new JavaMultiThreadedBackend());
 65  * </pre>
 66  * or a {@code java.util.function.Predicate<Backend>} which can be used to select the required {@code Backend}
 67  * loaded via Javas ServiceLoader mechanism
 68  * {@code}
 69  * <pre>
 70  * Accelerator accelerator =
 71  *    new Accelerator(MethodHandles.lookup(),
 72  *        be -> be.name().startsWith("OpenCL));
 73  * </pre>}
 74  *
 75  * @author Gary Frost
 76  */
 77 public class Accelerator implements BufferAllocator, BufferTracker {
 78     public MethodHandles.Lookup lookup;
 79     public final Backend backend;
 80 
 81     private final Map<Method, hat.ComputeContext> cache = new HashMap<>();
 82 
 83     public KernelContext range(NDRange ndRange) {
 84         return new KernelContext(ndRange);
 85     }
 86 
 87     protected Accelerator(MethodHandles.Lookup lookup, ServiceLoader.Provider<Backend> provider) {
 88         this(lookup, provider.get());
 89     }
 90     public Accelerator(MethodHandles.Lookup lookup) {
 91         this(lookup, FIRST);
 92     }
 93 
 94     /**
 95      * @param lookup
 96      * @param backend
 97      */
 98     public Accelerator(MethodHandles.Lookup lookup, Backend backend) {
 99         this.lookup = lookup;
100         this.backend = backend;
101     }
102 
103     /**
104      * @param lookup
105      * @param backendPredicate
106      */
107     public Accelerator(MethodHandles.Lookup lookup, Predicate<Backend> backendPredicate) {
108         this(lookup, Backend.getBackend(backendPredicate));
109     }
110 
111     @Override
112     public <T extends Buffer> T allocate(SegmentMapper<T> segmentMapper, BoundSchema<T> boundShema) {
113         return backend.allocate(segmentMapper, boundShema);
114     }
115 
116     @Override
117     public void preMutate(Buffer b) {
118         if (backend instanceof BufferTracker) {
119             ((BufferTracker) backend).preMutate(b);
120         }
121     }
122 
123     @Override
124     public void postMutate(Buffer b) {
125         if (backend instanceof BufferTracker) {
126             ((BufferTracker) backend).postMutate(b);
127         }
128     }
129 
130     @Override
131     public void preAccess(Buffer b) {
132         if (backend instanceof BufferTracker) {
133             ((BufferTracker) backend).preAccess(b);
134         }
135     }
136 
137     @Override
138     public void postAccess(Buffer b) {
139         if (backend instanceof BufferTracker) {
140             ((BufferTracker) backend).postAccess(b);
141         }
142     }
143 
144     /**
145      * An interface used for wrapping the compute entrypoint of work to be performed by the Accelerator.
146      * <p/>
147      * So given a ComputeClass such as...
148      * <pre>
149      *  public class MyComputeClass {
150      *    @ CodeReflection
151      *    public static void addDeltaKernel(KernelContext kc, S32Array arrayOfInt, int delta) {
152      *        arrayOfInt.array(kc.x, arrayOfInt.array(kc.x)+delta);
153      *    }
154      *
155      *    @ CodeReflection
156      *    static public void doSomeWork(final ComputeContext cc, S32Array arrayOfInt) {
157      *    }
158      *  }
159      *  </pre>
160      * The accelerator will be passed the doSomeWork entrypoint, wrapped in a {@code QuotableComputeContextConsumer}
161      * <pre>
162      *  accelerator.compute(cc ->
163      *     MyCompute.doSomeWork(cc, arrayOfInt)
164      *  );
165      *  </pre>
166      */
167     public interface QuotableComputeContextConsumer extends Quotable, Consumer<ComputeContext> {
168     }
169     // convenience
170     public Config config(){
171         return backend.config();
172     }
173 
174     /**
175      * This method provides the Accelerator with the {@code Compute Entrypoint} from a Compute class.
176      * <p>
177      * The entrypoint is wrapped in a <a href="QuotableComputeContextConsumer.html">QuotableComputeContextConsumer</a> lambda.
178      *
179      * <pre>
180      * accelerator.compute(cc -&gt;
181      *     MyCompute.doSomeWork(cc, intArray)
182      * )
183      * </pre>
184      */
185     public void compute(QuotableComputeContextConsumer quotableComputeContextConsumer) {
186         Quoted quoted = Op.ofQuotable(quotableComputeContextConsumer).orElseThrow();
187         JavaOp.LambdaOp lambda = (JavaOp.LambdaOp) quoted.op();
188         Method method = OpTk.methodOrThrow(lookup,OpTk.getQuotableTargetInvokeOpWrapper(lambda));
189         // Create (or get cached) a compute context which closes over compute entryppint and reachable kernels.
190         // The models of all compute and kernel methods are passed to the backend during creation
191         // The backend may well mutate the models.
192         // It will also use this opportunity to generate ISA specific code for the kernels.
193         ComputeContext computeContext = cache.computeIfAbsent(method, (_) -> new ComputeContext(this, method));
194         // Here we get the captured values  from the Quotable
195         Object[] args = OpTk.getQuotableCapturedValues(lambda,quoted, method);
196         args[0] = computeContext;
197         // now ask the backend to execute
198         backend.dispatchCompute(computeContext, args);
199     }
200 }