将getrusage从linux转换为windows

Question

我正在将linux代码转换为C++，并且正在为替换这个getrusage方法而奋斗。

1.    timeval CPUStopwatch::now_timeval() const {
2.        rusage ru;
3.        getrusage(RUSAGE_SELF, &ru);
4.        return ru.ru_utime;
5.    }

如何将这一行(3)解析为工作的窗口行？我已经实现了rusage和timeval类，所以它们不会成为一个问题。

Answer 1

在PostgreSQL源代码中可以找到：

 /*
 * This code works on:
 *      solaris_i386
 *      solaris_sparc
 *      hpux 9.*
 *      win32
 * which currently is all the supported platforms that don't have a
 * native version of getrusage().  So, if configure decides to compile
 * this file at all, we just use this version unconditionally.
 */

int
getrusage(int who, struct rusage *rusage)
{
#ifdef WIN32
    FILETIME    starttime;
    FILETIME    exittime;
    FILETIME    kerneltime;
    FILETIME    usertime;
    ULARGE_INTEGER li;

    if (who != RUSAGE_SELF)
    {
        /* Only RUSAGE_SELF is supported in this implementation for now */
        errno = EINVAL;
        return -1;
    }

    if (rusage == (struct rusage *) NULL)
    {
        errno = EFAULT;
        return -1;
    }
    memset(rusage, 0, sizeof(struct rusage));
    if (GetProcessTimes(GetCurrentProcess(),
                        &starttime, &exittime, &kerneltime, &usertime) == 0)
    {
        _dosmaperr(GetLastError());
        return -1;
    }

    /* Convert FILETIMEs (0.1 us) to struct timeval */
    memcpy(&li, &kerneltime, sizeof(FILETIME));
    li.QuadPart /= 10L;         /* Convert to microseconds */
    rusage->ru_stime.tv_sec = li.QuadPart / 1000000L;
    rusage->ru_stime.tv_usec = li.QuadPart % 1000000L;

    memcpy(&li, &usertime, sizeof(FILETIME));
    li.QuadPart /= 10L;         /* Convert to microseconds */
    rusage->ru_utime.tv_sec = li.QuadPart / 1000000L;
    rusage->ru_utime.tv_usec = li.QuadPart % 1000000L;
#else                           /* all but WIN32 */

来自https://github.com/postgres/postgres/blob/7559d8ebfa11d98728e816f6b655582ce41150f3/src/port/getrusage.c