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/*
Copyright 2005-2011 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.
*/
/* Example program that shows how to use parallel_do to do parallel preorder
traversal of a directed acyclic graph. */
#include <cstdlib>
#include "tbb/task_scheduler_init.h"
#include "tbb/tick_count.h"
#include "../../common/utility/utility.h"
#include <iostream>
#include <vector>
#include "Graph.h"
// some forward declarations
class Cell;
void ParallelPreorderTraversal( const std::vector<Cell*>& root_set );
//------------------------------------------------------------------------
// Test driver
//------------------------------------------------------------------------
utility::thread_number_range threads(tbb::task_scheduler_init::default_num_threads);
static unsigned nodes = 1000;
static unsigned traversals = 500;
static bool SilentFlag = false;
//! Parse the command line.
static void ParseCommandLine( int argc, const char* argv[] ) {
utility::parse_cli_arguments(
argc,argv,
utility::cli_argument_pack()
//"-h" option for for displaying help is present implicitly
.positional_arg(threads,"n-of-threads","number of threads to use; a range of the form low[:high], where low and optional high are non-negative integers or 'auto' for the TBB default.")
.positional_arg(nodes,"n-of-nodes","number of nodes in the graph.")
.positional_arg(traversals,"n-of-traversals","number of times to evaluate the graph. Reduce it (e.g. to 100) to shorten example run time\n")
.arg(SilentFlag,"silent","no output except elapsed time ")
);
}
int main( int argc, const char* argv[] ) {
try {
tbb::tick_count main_start = tbb::tick_count::now();
ParseCommandLine(argc,argv);
// Start scheduler with given number of threads.
for( int p=threads.first; p<=threads.last; ++p ) {
tbb::tick_count t0 = tbb::tick_count::now();
tbb::task_scheduler_init init(p);
srand(2);
size_t root_set_size = 0;
{
Graph g;
g.create_random_dag(nodes);
std::vector<Cell*> root_set;
g.get_root_set(root_set);
root_set_size = root_set.size();
for( unsigned int trial=0; trial<traversals; ++trial ) {
ParallelPreorderTraversal(root_set);
}
}
tbb::tick_count::interval_t interval = tbb::tick_count::now()-t0;
if (!SilentFlag){
std::cout
<<interval.seconds()<<" seconds using "<<p<<" threads ("<<root_set_size<<" nodes in root_set)\n";
}
}
utility::report_elapsed_time((tbb::tick_count::now()-main_start).seconds());
return 0;
}catch(std::exception& e){
std::cerr
<< "unexpected error occurred. \n"
<< "error description: "<<e.what()<<std::endl;
return -1;
}
}
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