7026304: Fork-Join sample
Implement a merge-sort sample using Fork-Join Reviewed-by: hosterda, chegar, dholmes
This commit is contained in:
parent
3382d83790
commit
f159608a01
jdk
make/mksample
src/share/sample/forkjoin/mergesort
test/sample/mergesort
@ -1,5 +1,5 @@
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#
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# Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
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# Copyright (c) 2004, 2011, Oracle and/or its affiliates. All rights reserved.
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# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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#
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# This code is free software; you can redistribute it and/or modify it
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@ -38,7 +38,7 @@ else
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endif
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SUBDIRS =
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SUBDIRS_misc = nio scripting nbproject
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SUBDIRS_misc = nio scripting nbproject forkjoin
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SUBDIRS_enterprise = $(WEBSERVICES_SUBDIR)
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SUBDIRS_management = jmx
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41
jdk/make/mksample/forkjoin/Makefile
Normal file
41
jdk/make/mksample/forkjoin/Makefile
Normal file
@ -0,0 +1,41 @@
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#
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# Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
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# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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#
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# This code is free software; you can redistribute it and/or modify it
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# under the terms of the GNU General Public License version 2 only, as
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# published by the Free Software Foundation. Oracle designates this
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# particular file as subject to the "Classpath" exception as provided
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# by Oracle in the LICENSE file that accompanied this code.
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#
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# This code is distributed in the hope that it will be useful, but WITHOUT
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# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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# version 2 for more details (a copy is included in the LICENSE file that
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# accompanied this code).
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#
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# You should have received a copy of the GNU General Public License version
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# 2 along with this work; if not, write to the Free Software Foundation,
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# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#
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# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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# or visit www.oracle.com if you need additional information or have any
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# questions.
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#
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#
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# Makefile for building all the samples under the forkjoin subdirectory.
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#
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BUILDDIR = ../..
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PRODUCT = java
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include $(BUILDDIR)/common/Defs.gmk
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SUBDIRS = mergesort
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include $(BUILDDIR)/common/Subdirs.gmk
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all build clean clobber::
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$(SUBDIRS-loop)
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clobber clean ::
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$(RM) -r $(SAMPLEDIR)/forkjoin
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51
jdk/make/mksample/forkjoin/mergesort/Makefile
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51
jdk/make/mksample/forkjoin/mergesort/Makefile
Normal file
@ -0,0 +1,51 @@
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#
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# Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
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# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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#
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# This code is free software; you can redistribute it and/or modify it
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# under the terms of the GNU General Public License version 2 only, as
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# published by the Free Software Foundation. Oracle designates this
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# particular file as subject to the "Classpath" exception as provided
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# by Oracle in the LICENSE file that accompanied this code.
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#
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# This code is distributed in the hope that it will be useful, but WITHOUT
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# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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# version 2 for more details (a copy is included in the LICENSE file that
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# accompanied this code).
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#
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# You should have received a copy of the GNU General Public License version
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# 2 along with this work; if not, write to the Free Software Foundation,
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# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#
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# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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# or visit www.oracle.com if you need additional information or have any
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# questions.
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#
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#
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# Makefile for the forkjoin/mergesort sample code
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#
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BUILDDIR = ../../..
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PRODUCT = java
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include $(BUILDDIR)/common/Defs.gmk
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SAMPLE_SRC_DIR = $(SHARE_SRC)/sample/forkjoin/mergesort
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SAMPLE_DST_DIR = $(SAMPLEDIR)/forkjoin/mergesort
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SAMPLE_FILES = \
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$(SAMPLE_DST_DIR)/MergeDemo.java \
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$(SAMPLE_DST_DIR)/MergeSort.java
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all build: $(SAMPLE_FILES)
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$(SAMPLE_DST_DIR)/%: $(SAMPLE_SRC_DIR)/%
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$(install-file)
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clean clobber:
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$(RM) -r $(SAMPLE_DST_DIR)
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.PHONY: all build clean clobber
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287
jdk/src/share/sample/forkjoin/mergesort/MergeDemo.java
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287
jdk/src/share/sample/forkjoin/mergesort/MergeDemo.java
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/*
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* Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* - Neither the name of Oracle nor the names of its
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* contributors may be used to endorse or promote products derived
|
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
|
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* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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import java.util.Arrays;
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import java.util.Random;
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import static java.lang.Integer.parseInt;
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/**
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* MergeExample is a class that runs a demo benchmark of the {@code ForkJoin} framework
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* by benchmarking a {@link MergeSort} algorithm that is implemented using
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* {@link java.util.concurrent.RecursiveAction}.
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* The {@code ForkJoin} framework is setup with different parallelism levels
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* and the sort is executed with arrays of different sizes to see the
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* trade offs by using multiple threads for different sizes of the array.
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*/
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public class MergeDemo {
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// Use a fixed seed to always get the same random values back
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private final Random random = new Random(759123751834L);
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private static final int ITERATIONS = 10;
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/**
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* Represents the formula {@code f(n) = start + (step * n)} for n = 0 & n < iterations
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*/
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private static class Range {
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private final int start;
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private final int step;
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private final int iterations;
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private Range(int start, int step, int iterations) {
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this.start = start;
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this.step = step;
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this.iterations = iterations;
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}
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/**
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* Parses start, step and iterations from args
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* @param args the string array containing the arguments
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* @param start which element to start the start argument from
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* @return the constructed range
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*/
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public static Range parse(String[] args, int start) {
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if (args.length < start + 3) {
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throw new IllegalArgumentException("Too few elements in array");
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}
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return new Range(parseInt(args[start]), parseInt(args[start + 1]), parseInt(args[start + 2]));
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}
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public int get(int iteration) {
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return start + (step * iteration);
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}
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public int getIterations() {
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return iterations;
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}
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@Override
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public String toString() {
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StringBuilder builder = new StringBuilder();
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builder.append(start).append(" ").append(step).append(" ").append(iterations);
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return builder.toString();
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}
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}
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/**
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* Wraps the different parameters that is used when running the MergeExample.
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* {@code sizes} represents the different array sizes
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* {@code parallelism} represents the different parallelism levels
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*/
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private static class Configuration {
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private final Range sizes;
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private final Range parallelism;
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private final static Configuration defaultConfig = new Configuration(new Range(20000, 20000, 10),
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new Range(2, 2, 10));
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private Configuration(Range sizes, Range parallelism) {
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this.sizes = sizes;
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this.parallelism = parallelism;
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}
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/**
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* Parses the arguments and attempts to create a configuration containing the
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* parameters for creating the array sizes and parallelism sizes
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* @param args the input arguments
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* @return the configuration
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*/
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public static Configuration parse(String[] args) {
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if (args.length == 0) {
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return defaultConfig;
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} else {
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try {
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if (args.length == 6) {
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return new Configuration(Range.parse(args, 0), Range.parse(args, 3));
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}
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} catch (NumberFormatException e) {
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System.err.println("MergeExample: error: Argument was not a number.");
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}
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System.err.println("MergeExample <size start> <size step> <size steps> <parallel start> <parallel step>" +
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" <parallel steps>");
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System.err.println("example: MergeExample 20000 10000 3 1 1 4");
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System.err.println("example: will run with arrays of sizes 20000, 30000, 40000" +
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" and parallelism: 1, 2, 3, 4");
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return null;
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}
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}
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/**
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* Creates an array for reporting the test result time in
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* @return an array containing {@code sizes.iterations * parallelism.iterations} elements
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*/
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private long[][] createTimesArray() {
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return new long[sizes.getIterations()][parallelism.getIterations()];
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}
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@Override
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public String toString() {
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StringBuilder builder = new StringBuilder("");
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if (this == defaultConfig) {
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builder.append("Default configuration. ");
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}
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builder.append("Running with parameters: ");
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builder.append(sizes);
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builder.append(" ");
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builder.append(parallelism);
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return builder.toString();
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}
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}
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/**
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* Generates an array of {@code elements} random elements
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* @param elements the number of elements requested in the array
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* @return an array of {@code elements} random elements
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*/
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private int[] generateArray(int elements) {
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int[] array = new int[elements];
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for (int i = 0; i < elements; ++i) {
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array[i] = random.nextInt();
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}
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return array;
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}
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/**
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* Runs the test
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* @param config contains the settings for the test
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*/
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private void run(Configuration config) {
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Range sizes = config.sizes;
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Range parallelism = config.parallelism;
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// Run a couple of sorts to make the JIT compile / optimize the code
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// which should produce somewhat more fair times
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warmup();
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long[][] times = config.createTimesArray();
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for (int size = 0; size < sizes.getIterations(); size++) {
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runForSize(parallelism, sizes.get(size), times, size);
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}
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printResults(sizes, parallelism, times);
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}
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/**
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* Prints the results as a table
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* @param sizes the different sizes of the arrays
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* @param parallelism the different parallelism levels used
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* @param times the median times for the different sizes / parallelism
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*/
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private void printResults(Range sizes, Range parallelism, long[][] times) {
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System.out.println("Time in milliseconds. Y-axis: number of elements. X-axis parallelism used.");
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long[] sums = new long[times[0].length];
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System.out.format("%8s ", "");
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for (int i = 0; i < times[0].length; i++) {
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System.out.format("%4d ", parallelism.get(i));
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}
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System.out.println("");
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for (int size = 0; size < sizes.getIterations(); size++) {
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System.out.format("%8d: ", sizes.get(size));
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for (int i = 0; i < times[size].length; i++) {
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sums[i] += times[size][i];
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System.out.format("%4d ", times[size][i]);
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}
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System.out.println("");
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}
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System.out.format("%8s: ", "Total");
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for (long sum : sums) {
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System.out.format("%4d ", sum);
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}
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System.out.println("");
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}
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private void runForSize(Range parallelism, int elements, long[][] times, int size) {
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for (int step = 0; step < parallelism.getIterations(); step++) {
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long time = runForParallelism(ITERATIONS, elements, parallelism.get(step));
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times[size][step] = time;
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}
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}
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/**
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* Runs <i>iterations</i> number of test sorts of a random array of <i>element</i> length
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* @param iterations number of iterations
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* @param elements number of elements in the random array
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* @param parallelism parallelism for the ForkJoin framework
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* @return the median time of runs
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*/
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private long runForParallelism(int iterations, int elements, int parallelism) {
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MergeSort mergeSort = new MergeSort(parallelism);
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long[] times = new long[iterations];
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for (int i = 0; i < iterations; i++) {
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// Suggest the VM to run a garbage collection to reduce the risk of getting one
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// while running the test run
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System.gc();
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long start = System.currentTimeMillis();
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mergeSort.sort(generateArray(elements));
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times[i] = System.currentTimeMillis() - start;
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}
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return medianValue(times);
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}
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/**
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* Calculates the median value of the array
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* @param times array of times
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* @return the median value
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*/
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private long medianValue(long[] times) {
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if (times.length == 0) {
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throw new IllegalArgumentException("Empty array");
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}
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// Make a copy of times to avoid having side effects on the parameter value
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Arrays.sort(times.clone());
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long median = times[times.length / 2];
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if (times.length > 1 && times.length % 2 != 0) {
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median = (median + times[times.length / 2 + 1]) / 2;
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}
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return median;
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}
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/**
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* Generates 1000 arrays of 1000 elements and sorts them as a warmup
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*/
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private void warmup() {
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MergeSort mergeSort = new MergeSort(Runtime.getRuntime().availableProcessors());
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for (int i = 0; i < 1000; i++) {
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mergeSort.sort(generateArray(1000));
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}
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}
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public static void main(String[] args) {
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Configuration configuration = Configuration.parse(args);
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if (configuration == null) {
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System.exit(1);
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}
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System.out.println(configuration);
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new MergeDemo().run(configuration);
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}
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}
|
128
jdk/src/share/sample/forkjoin/mergesort/MergeSort.java
Normal file
128
jdk/src/share/sample/forkjoin/mergesort/MergeSort.java
Normal file
@ -0,0 +1,128 @@
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/*
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||||
* Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
*
|
||||
* - Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
*
|
||||
* - Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
*
|
||||
* - Neither the name of Oracle nor the names of its
|
||||
* contributors may be used to endorse or promote products derived
|
||||
* from this software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
|
||||
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
|
||||
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
||||
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
|
||||
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
||||
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
||||
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
||||
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
||||
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
||||
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
||||
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
import java.util.Arrays;
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import java.util.concurrent.ForkJoinPool;
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import java.util.concurrent.ForkJoinTask;
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import java.util.concurrent.RecursiveAction;
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|
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/**
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* A class for sorting an array of {@code ints} in parallel.
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* A {@code ForkJoinPool} is used for the parallelism, using the merge sort
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* algorithm the array is split into halves and a new sub task is created
|
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* for each part. Each sub task is dispatched to the {@code ForkJoinPool}
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* which will schedule the task to a {@code Thread}.
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* This happens until the size of the array is at most 2
|
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* elements long. At this point the array is sorted using a simple compare
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* and possibly a swap. The tasks then finish by using insert sort to
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* merge the two just sorted arrays.
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*
|
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* The idea of this class is to demonstrate the usage of RecursiveAction not
|
||||
* to implement the best possible parallel merge sort. This version creates
|
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* a small array for each merge (creating a lot of objects), this could
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* be avoided by keeping a single array.
|
||||
*/
|
||||
public class MergeSort {
|
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private final ForkJoinPool pool;
|
||||
|
||||
private static class MergeSortTask extends RecursiveAction {
|
||||
private final int[] array;
|
||||
private final int low;
|
||||
private final int high;
|
||||
private static final int THRESHOLD = 8;
|
||||
|
||||
/**
|
||||
* Creates a {@code MergeSortTask} containing the array and the bounds of the array
|
||||
*
|
||||
* @param array the array to sort
|
||||
* @param low the lower element to start sorting at
|
||||
* @param high the non-inclusive high element to sort to
|
||||
*/
|
||||
protected MergeSortTask(int[] array, int low, int high) {
|
||||
this.array = array;
|
||||
this.low = low;
|
||||
this.high = high;
|
||||
}
|
||||
|
||||
@Override
|
||||
protected void compute() {
|
||||
if (high - low <= THRESHOLD) {
|
||||
Arrays.sort(array, low, high);
|
||||
} else {
|
||||
int middle = low + ((high - low) >> 1);
|
||||
// Execute the sub tasks and wait for them to finish
|
||||
invokeAll(new MergeSortTask(array, low, middle), new MergeSortTask(array, middle, high));
|
||||
// Then merge the results
|
||||
merge(middle);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Merges the two sorted arrays this.low, middle - 1 and middle, this.high - 1
|
||||
* @param middle the index in the array where the second sorted list begins
|
||||
*/
|
||||
private void merge(int middle) {
|
||||
if (array[middle - 1] < array[middle]) {
|
||||
return; // the arrays are already correctly sorted, so we can skip the merge
|
||||
}
|
||||
int[] copy = new int[high - low];
|
||||
System.arraycopy(array, low, copy, 0, copy.length);
|
||||
int copyLow = 0;
|
||||
int copyHigh = high - low;
|
||||
int copyMiddle = middle - low;
|
||||
|
||||
for (int i = low, p = copyLow, q = copyMiddle; i < high; i++) {
|
||||
if (q >= copyHigh || (p < copyMiddle && copy[p] < copy[q]) ) {
|
||||
array[i] = copy[p++];
|
||||
} else {
|
||||
array[i] = copy[q++];
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Creates a {@code MergeSort} containing a ForkJoinPool with the indicated parallelism level
|
||||
* @param parallelism the parallelism level used
|
||||
*/
|
||||
public MergeSort(int parallelism) {
|
||||
pool = new ForkJoinPool(parallelism);
|
||||
}
|
||||
|
||||
/**
|
||||
* Sorts all the elements of the given array using the ForkJoin framework
|
||||
* @param array the array to sort
|
||||
*/
|
||||
public void sort(int[] array) {
|
||||
ForkJoinTask<Void> job = pool.submit(new MergeSortTask(array, 0, array.length));
|
||||
job.join();
|
||||
}
|
||||
}
|
102
jdk/test/sample/mergesort/MergeSortTest.java
Normal file
102
jdk/test/sample/mergesort/MergeSortTest.java
Normal file
@ -0,0 +1,102 @@
|
||||
/*
|
||||
* Copyright (c) 2011 Oracle and/or its affiliates. All rights reserved.
|
||||
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
||||
*
|
||||
* This code is free software; you can redistribute it and/or modify it
|
||||
* under the terms of the GNU General Public License version 2 only, as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This code is distributed in the hope that it will be useful, but WITHOUT
|
||||
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||||
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||||
* version 2 for more details (a copy is included in the LICENSE file that
|
||||
* accompanied this code).
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License version
|
||||
* 2 along with this work; if not, write to the Free Software Foundation,
|
||||
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
||||
*
|
||||
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
||||
* or visit www.oracle.com if you need additional information or have any
|
||||
* questions.
|
||||
*/
|
||||
|
||||
|
||||
/* @test
|
||||
* @summary Test MergeSort
|
||||
*
|
||||
* @library ../../../src/share/sample/forkjoin/mergesort
|
||||
* @build MergeSortTest MergeDemo MergeSort
|
||||
* @run main MergeSortTest
|
||||
*/
|
||||
|
||||
import java.util.Arrays;
|
||||
import java.util.Random;
|
||||
|
||||
public class MergeSortTest {
|
||||
private Random random;
|
||||
private MergeSort target;
|
||||
|
||||
public MergeSortTest(Random random, MergeSort target) {
|
||||
this.random = random;
|
||||
this.target = target;
|
||||
}
|
||||
|
||||
public static void main(String[] args) {
|
||||
MergeSortTest test = new MergeSortTest(new Random(), new MergeSort(Runtime.getRuntime().availableProcessors() * 4));
|
||||
test.run();
|
||||
}
|
||||
|
||||
private int[] generateArray(int elements) {
|
||||
int[] array = new int[elements];
|
||||
for (int i = 0; i < array.length; ++i) {
|
||||
array[i] = random.nextInt(10);
|
||||
}
|
||||
return array;
|
||||
}
|
||||
|
||||
private void run() {
|
||||
testSort();
|
||||
testSortSingle();
|
||||
testSortEmpty();
|
||||
testLong();
|
||||
}
|
||||
|
||||
public void testLong() {
|
||||
for (int i = 0; i < 1000; ++i) {
|
||||
int elements = 1 + i * 100;
|
||||
|
||||
int[] array = generateArray(elements);
|
||||
int[] copy = Arrays.copyOf(array, array.length);
|
||||
Arrays.sort(copy);
|
||||
target.sort(array);
|
||||
assertEqual(copy, array);
|
||||
}
|
||||
}
|
||||
|
||||
private void testSortEmpty() {
|
||||
int[] array = { };
|
||||
target.sort(array);
|
||||
assertEqual(new int[] { }, array);
|
||||
}
|
||||
|
||||
private void testSortSingle() {
|
||||
int[] array = { 1 };
|
||||
target.sort(array);
|
||||
assertEqual(new int[] { 1 }, array);
|
||||
}
|
||||
|
||||
private void testSort() {
|
||||
int[] array = { 7, 3, 9, 0, -6, 12, 54, 3, -6, 88, 1412};
|
||||
target.sort(array);
|
||||
assertEqual(new int[] { -6, -6, 0, 3, 3, 7, 9, 12, 54, 88, 1412 }, array);
|
||||
}
|
||||
|
||||
private void assertEqual(int[] expected, int[] array) {
|
||||
if (!Arrays.equals(expected, array)) {
|
||||
throw new RuntimeException("Invalid sorted array!");
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
}
|
Loading…
x
Reference in New Issue
Block a user