parallel_preorder.cpp File Reference

#include "tbb/parallel_do.h"
#include "tbb/atomic.h"
#include <vector>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include "Graph.h"
#include <cctype>
#include "tbb/task_scheduler_init.h"
#include "tbb/tick_count.h"

Include dependency graph for parallel_preorder.cpp:

Go to the source code of this file.

Classes
class	Body
struct	IntRange
	A closed range of int.
Functions
int	main (int argc, char *argv[])
void	ParallelPreorderTraversal (const vector< Cell * > &root_set)
static void	ParseCommandLine (int argc, char *argv[])
	Parse the command line.
void	Usage (char *argv0)
	Displays usage message.
Variables
static IntRange	NThread (1, 4)
	Number of threads to use.
int	ntrial = 50
	Number of trials. Can be changed from command line.
static bool	PauseFlag = false
	If true, then at end wait for user to hit return.

---

Function Documentation

int main	(	int	argc,
		char *	argv[]
	)

Definition at line 143 of file parallel_preorder.cpp.

References Graph::create_random_dag(), g, Graph::get_root_set(), IntRange::high, IntRange::low, tbb::tick_count::now(), NThread, ntrial, ParallelPreorderTraversal(), ParseCommandLine(), PauseFlag, tbb::tick_count::interval_t::seconds(), and t0.

                                   {
    ParseCommandLine(argc,argv);

    // Start scheduler with given number of threads.
    for( int p=NThread.low; p<=NThread.high; ++p ) {
        tbb::task_scheduler_init init(p);
        srand(2);
        tbb::tick_count::interval_t interval;
        size_t total_root_set_size = 0;
        for( int trial=0; trial<ntrial; ++trial ) {
            Graph g;
            g.create_random_dag(1000);
            vector<Cell*> root_set;
            g.get_root_set(root_set);
            total_root_set_size += root_set.size();

            tbb::tick_count t0 = tbb::tick_count::now();
            for( int i=0; i<10; ++i ) {
                ParallelPreorderTraversal(root_set);
            }
            tbb::tick_count t1 = tbb::tick_count::now();

            interval += t1-t0;
        }
        printf("%g seconds using %d threads (average of %g nodes in root_set)\n",interval.seconds(),p,(double)total_root_set_size/ntrial);
    }

    if (PauseFlag) {
        printf ("Press return key to exit");
        char c;
        int n = scanf("%c", &c);
        if( n!=1 ) {
            fprintf(stderr,"Fatal error: unexpected end of input\n");
            exit(1);
        }
    }

    return 0;
}

void ParallelPreorderTraversal

(

const vector< Cell * > &

root_set

)

Definition at line 67 of file parallel_preorder.cpp.

References tbb::parallel_do().

Referenced by main().

                                                                {
    tbb::parallel_do(root_set.begin(), root_set.end(),Body());
}

static void ParseCommandLine	(	int	argc,
		char *	argv[]
	)		[static]

Definition at line 116 of file parallel_preorder.cpp.

References NThread, ntrial, PauseFlag, IntRange::set_from_string(), and Usage().

                                                       {
    int i = 1;
        if( i<argc && !isdigit(argv[i][0]) ) { 
        // Command line is garbled.
        Usage(argv[0]);
        exit(1);
    }
    if( i<argc )
        NThread.set_from_string(argv[i++]);
    if( i<argc && !isdigit(argv[i][0]) ) { 
        // Command line is garbled.
        Usage(argv[0]);
        exit(1);
    }
    if (i<argc) {
        ntrial = strtol(argv[i++], 0, 0);
    }
    if (ntrial == 0) {
        // Command line is garbled.
        Usage(argv[0]);
        exit(1);
    }
    if (i<argc && strcmp( argv[i], "pause" )==0 ) {
        PauseFlag = true;
    }
}

void Usage

(

char *

argv0

)

Definition at line 108 of file parallel_preorder.cpp.

References IntRange::high, IntRange::low, and NThread.

Referenced by ParseCmdLine(), ParseCommandLine(), and run_pipeline().

                         {
    fprintf(stderr, "Usage: %s [nthread [ntrials ['pause']]]\n", argv0);
    fprintf(stderr, "where nthread is a non-negative integer, or range of the form low:high [%d:%d]\n", NThread.low, NThread.high);
    fprintf(stderr, "ntrials is a positive integer. Default value is 50, reduce it (e.g. to 5) to shorten example run time\n");
    fprintf(stderr, "The application waits for user to hit return if 'pause' is specified\n");
}

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Variable Documentation

IntRange NThread(1, 4) [static]

Referenced by main(), ParseCommandLine(), and Usage().

int ntrial = 50

Definition at line 43 of file parallel_preorder.cpp.

Referenced by main(), and ParseCommandLine().

bool PauseFlag = false [static]

Definition at line 105 of file parallel_preorder.cpp.

Referenced by main(), and ParseCommandLine().