| /* |
| Copyright 2005-2010 Intel Corporation. All Rights Reserved. |
| |
| This file is part of Threading Building Blocks. |
| |
| Threading Building Blocks is free software; you can redistribute it |
| and/or modify it under the terms of the GNU General Public License |
| version 2 as published by the Free Software Foundation. |
| |
| Threading Building Blocks 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with Threading Building Blocks; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| |
| As a special exception, you may use this file as part of a free software |
| library without restriction. Specifically, if other files instantiate |
| templates or use macros or inline functions from this file, or you compile |
| this file and link it with other files to produce an executable, this |
| file does not by itself cause the resulting executable to be covered by |
| the GNU General Public License. This exception does not however |
| invalidate any other reasons why the executable file might be covered by |
| the GNU General Public License. |
| */ |
| |
| #include <cstdio> |
| #include <cstdlib> |
| |
| #include "tbb/task_scheduler_init.h" |
| #include "tbb/task.h" |
| #include "tbb/tick_count.h" |
| |
| extern long CutOff; |
| |
| long SerialFib( const long n ) { |
| if( n<2 ) |
| return n; |
| else |
| return SerialFib(n-1)+SerialFib(n-2); |
| } |
| |
| struct FibContinuation: public tbb::task { |
| long* const sum; |
| long x, y; |
| FibContinuation( long* sum_ ) : sum(sum_) {} |
| tbb::task* execute() { |
| *sum = x+y; |
| return NULL; |
| } |
| }; |
| |
| struct FibTask: public tbb::task { |
| long n; |
| long * sum; |
| FibTask( const long n_, long * const sum_ ) : |
| n(n_), sum(sum_) |
| {} |
| tbb::task* execute() { |
| if( n<CutOff ) { |
| *sum = SerialFib(n); |
| return NULL; |
| } else { |
| FibContinuation& c = |
| *new( allocate_continuation() ) FibContinuation(sum); |
| FibTask& b = *new( c.allocate_child() ) FibTask(n-1,&c.y); |
| recycle_as_child_of(c); |
| n -= 2; |
| sum = &c.x; |
| // Set ref_count to "two children". |
| c.set_ref_count(2); |
| c.spawn( b ); |
| return this; |
| } |
| } |
| }; |
| |
| long ParallelFib( const long n ) { |
| long sum = 0; |
| FibTask& a = *new(tbb::task::allocate_root()) FibTask(n,&sum); |
| tbb::task::spawn_root_and_wait(a); |
| return sum; |
| } |
| |