org.nd4j.linalg.factory.Nd4jBackend Maven / Gradle / Ivy
/*
*
* * Copyright 2015 Skymind,Inc.
* *
* * Licensed under the Apache License, Version 2.0 (the "License");
* * you may not use this file except in compliance with the License.
* * You may obtain a copy of the License at
* *
* * http://www.apache.org/licenses/LICENSE-2.0
* *
* * Unless required by applicable law or agreed to in writing, software
* * distributed under the License is distributed on an "AS IS" BASIS,
* * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* * See the License for the specific language governing permissions and
* * limitations under the License.
*
*
*/
package org.nd4j.linalg.factory;
import java.io.IOException;
import java.util.*;
import org.nd4j.linalg.io.Resource;
import org.reflections.Reflections;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* An ND4j backend.
*
* @author eronwright
*
*/
public abstract class Nd4jBackend {
public static final int BACKEND_PRIORITY_CPU = 0;
public static final int BACKEND_PRIORITY_GPU = 100;
private static final Logger log = LoggerFactory.getLogger(Nd4jBackend.class);
private Properties props;
/**
* Gets a priority number for the backend.
*
* Backends are loaded in priority order (highest first).
* @return a priority number.
*/
public abstract int getPriority();
/**
* Determines whether a given backend is available in the current environment.
* @return true if the backend is available; false otherwise.
*/
public abstract boolean isAvailable();
/**
* Returns true if the backend can
* run on the os or not
* @return
*/
public abstract boolean canRun();
/**
* Get the configuration resource
* @return
*/
public abstract Resource getConfigurationResource();
/**
* Loads the best available backend.
* @return
*/
public static Nd4jBackend load() throws NoAvailableBackendException {
List backends = new ArrayList<>(1);
ServiceLoader loader = ServiceLoader.load(Nd4jBackend.class);
try {
Iterator backendIterator = loader.iterator();
while(backendIterator.hasNext())
backends.add(backendIterator.next());
} catch (ServiceConfigurationError serviceError) {
// a fatal error due to a syntax or provider construction error.
// backends mustn't throw an exception during construction.
throw new RuntimeException("failed to process available backends", serviceError);
}
Collections.sort(backends, new Comparator() {
@Override
public int compare(Nd4jBackend o1, Nd4jBackend o2) {
// high-priority first
return o2.getPriority() - o1.getPriority();
}
});
for(Nd4jBackend backend: backends) {
if(!backend.isAvailable()) {
log.trace("Skipped [{}] backend (unavailable)", backend.getClass().getSimpleName());
continue;
}
log.trace("Loaded [{}] backend", backend.getClass().getSimpleName());
return backend;
}
log.trace("Service loader failed...falling back to reflection");
Set> clazzes = new Reflections("org.nd4j").getSubTypesOf(Nd4jBackend.class);
List reflectionBackends = new ArrayList<>();
for(Class backend : clazzes) {
try {
Nd4jBackend load = backend.newInstance();
reflectionBackends.add(load);
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
Collections.sort(backends, new Comparator() {
@Override
public int compare(Nd4jBackend o1, Nd4jBackend o2) {
// high-priority first
return o2.getPriority() - o1.getPriority();
}
});
for(Nd4jBackend backend: reflectionBackends) {
if(!backend.isAvailable()) {
log.trace("Skipped [{}] backend (unavailable)", backend.getClass().getSimpleName());
continue;
}
log.info("Loaded [{}] backend", backend.getClass().getSimpleName());
return backend;
}
throw new NoAvailableBackendException();
}
public Properties getProperties() throws IOException {
if(props != null)
return props;
props = new Properties();
props.load(getConfigurationResource().getInputStream());
return props;
}
@SuppressWarnings("serial")
public static class NoAvailableBackendException extends Exception {}
}