timestamp.c

linux下的多线程调试工具

/* Copyright (C) 2004,2005,2006  Bull S.A.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#if HAVE_CONFIG_H
#include <config.h>
#endif

#define _GNU_SOURCE
#include <string.h>
#include <time.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "timestamp.h"
#include "types.h"

ptt_timestamp_t get_timestamp() {
    ptt_timestamp_t timestamp;

#if defined(__powerpc__) 
    unsigned long lower, upper, tmp;
    do {
        __asm__ __volatile__ ("mftbu %0    #load from TBU" : "=r" (upper) :);
        __asm__ __volatile__ ("mftb  %0    #load from TBL" : "=r" (lower) :);
        __asm__ __volatile__ ("mftbu %0    #load from TBU" : "=r" (tmp)   :);
    } while (upper != tmp); /* loop if carry occurred */
    timestamp = ((hp_timing_t)(upper)<<32)|(lower&0xffffffff);
#elif defined(__powerpc64__)
    __asm__ __volatile__ ( "mftb %0": "=r" (timestamp) :);
#elif ((defined(__i386__)) || (defined(__x86_64__)))
    __asm__ __volatile__ ("rdtsc" : "=A" (timestamp));
#elif defined(__ia64__)
#define REPEAT_READ(val) __builtin_expect ((long int) val == -1, 0)
unsigned long int __itc;
    do asm volatile ("mov %0=ar.itc" : "=r" (__itc) : : "memory");
    while (REPEAT_READ (__itc));
    timestamp = __itc;
#else
#error unsupported arch
#endif

    return timestamp;
}

/* read the information from /proc filesystem.
 * contains at least one line like:
 *      cpu MHz         : 497.840237
 * or also
 *      cpu MHz         : 497.841
 * search for this line and convert the number in an integer.
 */
int get_clockfreq_khz (void) {
    long long result = 0;
    int fd;
    /* proc filesystem generates "files" up to a size of 4096 bytes. */
    char buffer[4096];
    ssize_t n;
    char *mhz, *endp;
    int seen_decpoint = 0, ndigits = 0;

    if ((fd = open ("/proc/cpuinfo", O_RDONLY)) == -1) return 0;
    if ((n = read (fd, buffer, sizeof(buffer))) == -1) return 0;

#if defined(__powerpc64__) || defined(__powerpc__)
    mhz = memmem (buffer, n, "timebase", 8);
#elif defined(__ia64)
    mhz = memmem (buffer, n, "itc MHz", 7);
#else
    mhz = memmem (buffer, n, "cpu MHz", 7);
#endif
    if (mhz == NULL) return 0;

    endp = buffer + n;
    while (mhz < endp && (*mhz < '0' || *mhz > '9') && *mhz != '\n') ++mhz;
    while (mhz < endp && *mhz != '\n') {
        if (*mhz >= '0' && *mhz <= '9') {
            result *= 10; result += *mhz - '0';
            if (seen_decpoint) ++ndigits;
        }
        else if (*mhz == '.') seen_decpoint = 1;
        ++mhz;
    }

#if !defined(__powerpc64__) || !defined(__powerpc__)
    /* compensate for missing digits at the end.  */
    while (ndigits++ < 6) result *= 10;
#endif

    close (fd);
    return result/1000;
}