pg_test_timing.c File Reference

#include "postgres_fe.h"
#include "getopt_long.h"
#include "portability/instr_time.h"

Include dependency graph for pg_test_timing.c:

Go to the source code of this file.

Functions
static void	handle_args (int argc, char *argv[])
static uint64	test_timing (int32)
static void	output (uint64 loop_count)
int	main (int argc, char *argv[])

Variables
static const char *	progname
static int32	test_duration = 3
int64	histogram [32]

Function Documentation

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

static

Definition at line 41 of file pg_test_timing.c.

References _, getopt_long(), ngettext, NULL, optarg, optind, progname, required_argument, and test_duration.

Referenced by main().

{
    static struct option long_options[] = {
        {"duration", required_argument, NULL, 'd'},
        {NULL, 0, NULL, 0}
    };

    int         option;         /* Command line option */
    int         optindex = 0;   /* used by getopt_long */

    if (argc > 1)
    {
        if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
        {
            printf(_("Usage: %s [-d DURATION]\n"), progname);
            exit(0);
        }
        if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
        {
            puts("pg_test_timing (PostgreSQL) " PG_VERSION);
            exit(0);
        }
    }

    while ((option = getopt_long(argc, argv, "d:",
                                 long_options, &optindex)) != -1)
    {
        switch (option)
        {
            case 'd':
                test_duration = atoi(optarg);
                break;

            default:
                fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                        progname);
                exit(1);
                break;
        }
    }

    if (argc > optind)
    {
        fprintf(stderr,
                _("%s: too many command-line arguments (first is \"%s\")\n"),
                progname, argv[optind]);
        fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                progname);
        exit(1);
    }

    if (test_duration > 0)
    {
        printf(ngettext("Testing timing overhead for %d second.\n",
                        "Testing timing overhead for %d seconds.\n",
                        test_duration),
               test_duration);
    }
    else
    {
        fprintf(stderr,
                _("%s: duration must be a positive integer (duration is \"%d\")\n"),
                progname, test_duration);
        fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                progname);
        exit(1);
    }
}

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

Definition at line 24 of file pg_test_timing.c.

References get_progname(), handle_args(), output(), PG_TEXTDOMAIN, progname, set_pglocale_pgservice(), test_duration, and test_timing().

{
    uint64      loop_count;

    set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_test_timing"));
    progname = get_progname(argv[0]);

    handle_args(argc, argv);

    loop_count = test_timing(test_duration);

    output(loop_count);

    return 0;
}

static void output ( uint64  loop_count )

static

Definition at line 171 of file pg_test_timing.c.

References _, buf, histogram, i, INT64_FORMAT, and snprintf().

Referenced by _crypt_blowfish_rn(), _crypt_gensalt_blowfish_rn(), _crypt_gensalt_extended_rn(), _crypt_gensalt_md5_rn(), _crypt_gensalt_traditional_rn(), adjust_data_dir(), brin_page_items(), CheckSCRAMAuth(), dttofmtasc_replace(), exec_command_sf(), exec_command_sv(), get_bin_version(), get_control_data(), helpSQL(), helpVariables(), main(), pg_SASL_continue(), poly2path(), printHistory(), px_crypt_des(), slashUsage(), statext_dependencies_serialize(), statext_ndistinct_serialize(), tbm_iterate(), tbm_shared_iterate(), and usage().

{
    int64       max_bit = 31,
                i;

    /* find highest bit value */
    while (max_bit > 0 && histogram[max_bit] == 0)
        max_bit--;

    printf(_("Histogram of timing durations:\n"));
    printf("%6s   %10s %10s\n", _("< us"), _("% of total"), _("count"));

    for (i = 0; i <= max_bit; i++)
    {
        char        buf[100];

        /* lame hack to work around INT64_FORMAT deficiencies */
        snprintf(buf, sizeof(buf), INT64_FORMAT, histogram[i]);
        printf("%6ld    %9.5f %10s\n", 1l << i,
               (double) histogram[i] * 100 / loop_count, buf);
    }
}

static uint64 test_timing ( int32  duration )

static

Definition at line 111 of file pg_test_timing.c.

References _, cur, end_time, histogram, INSTR_TIME_GET_DOUBLE, INSTR_TIME_GET_MICROSEC, INSTR_TIME_SET_CURRENT, INSTR_TIME_SUBTRACT, INT64CONST, and start_time.

Referenced by main().

{
    uint64      total_time;
    int64       time_elapsed = 0;
    uint64      loop_count = 0;
    uint64      prev,
                cur;
    instr_time  start_time,
                end_time,
                temp;

    total_time = duration > 0 ? duration * INT64CONST(1000000) : 0;

    INSTR_TIME_SET_CURRENT(start_time);
    cur = INSTR_TIME_GET_MICROSEC(start_time);

    while (time_elapsed < total_time)
    {
        int32       diff,
                    bits = 0;

        prev = cur;
        INSTR_TIME_SET_CURRENT(temp);
        cur = INSTR_TIME_GET_MICROSEC(temp);
        diff = cur - prev;

        /* Did time go backwards? */
        if (diff < 0)
        {
            fprintf(stderr, _("Detected clock going backwards in time.\n"));
            fprintf(stderr, _("Time warp: %d ms\n"), diff);
            exit(1);
        }

        /* What is the highest bit in the time diff? */
        while (diff)
        {
            diff >>= 1;
            bits++;
        }

        /* Update appropriate duration bucket */
        histogram[bits]++;

        loop_count++;
        INSTR_TIME_SUBTRACT(temp, start_time);
        time_elapsed = INSTR_TIME_GET_MICROSEC(temp);
    }

    INSTR_TIME_SET_CURRENT(end_time);

    INSTR_TIME_SUBTRACT(end_time, start_time);

    printf(_("Per loop time including overhead: %0.2f ns\n"),
           INSTR_TIME_GET_DOUBLE(end_time) * 1e9 / loop_count);

    return loop_count;
}

Variable Documentation

int64 histogram[32]

Definition at line 21 of file pg_test_timing.c.

Referenced by output(), and test_timing().

const char* progname

static

Definition at line 12 of file pg_test_timing.c.

Referenced by handle_args(), and main().

int32 test_duration = 3

static

Definition at line 14 of file pg_test_timing.c.

Referenced by handle_args(), and main().