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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/licenses/publicdomain |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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//import jsr166y.*; |
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}; // see http://www.durangobill.com/N_Queens.html |
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static final int FIRST_SIZE = 8; // smaller ones too short to measure well |
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static final int LAST_SIZE = 15; // bigger ones too long to wait for |
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static final int LAST_SIZE = 16; // bigger ones too long to wait for |
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/** for time conversion */ |
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static final long NPS = (1000L * 1000 * 1000); |
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public static void main(String[] args) throws Exception { |
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int procs = 0; |
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try { |
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return; |
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} |
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for (int reps = 0; reps < 2; ++reps) { |
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ForkJoinPool g = procs == 0? new ForkJoinPool() : |
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ForkJoinPool g = (procs == 0) ? ForkJoinPool.commonPool() : |
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new ForkJoinPool(procs); |
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lastStealCount = g.getStealCount(); |
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for (int i = FIRST_SIZE; i <= LAST_SIZE; i++) |
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test(g, i); |
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System.out.println(g); |
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g.shutdown(); |
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if (g != ForkJoinPool.commonPool()) |
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g.shutdown(); |
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Thread.sleep(100); |
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} |
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} |
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lastStealCount = sc; |
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System.out.printf(" Steals/t: %5d", ns/ps); |
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System.out.println(); |
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} |
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} |
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// Boards are represented as arrays where each cell |
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// Boards are represented as arrays where each cell |
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// holds the column number of the queen in that row |
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final int[] sofar; |
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NQueensCS nextSubtask; // to link subtasks |
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int solutions; |
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NQueensCS(int[] a) { |
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this.sofar = a; |
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NQueensCS(int[] a) { |
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this.sofar = a; |
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} |
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public final void compute() { |
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private static int processSubtasks(NQueensCS s) { |
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// Always run first the task held instead of forked |
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s.compute(); |
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s.compute(); |
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int ns = s.solutions; |
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s = s.nextSubtask; |
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/* comment out to stress join |
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// Then the unstolen ones |
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while (s != null && s.tryUnfork()) { |
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s.compute(); |
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ns += s.solutions; |
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s = s.nextSubtask; |
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} |
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*/ |
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// Then wait for the stolen ones |
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while (s != null) { |
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s.join(); |