third_party/ulib/musl/src/stdio/fflush.c

#include "stdio_impl.h"

static int __fflush_unlocked(FILE* f) {
    /* If writing, flush output */
    if (f->wpos > f->wbase) {
        f->write(f, 0, 0);
        if (!f->wpos)
            return EOF;
    }

    /* If reading, sync position, per POSIX */
    if (f->rpos < f->rend)
        f->seek(f, f->rpos - f->rend, SEEK_CUR);

    /* Clear read and write modes */
    f->wpos = f->wbase = f->wend = 0;
    f->rpos = f->rend = 0;

    return 0;
}

int fflush(FILE* f) {
    int r;

    if (f) {
        FLOCK(f);
        r = __fflush_unlocked(f);
        FUNLOCK(f);
        return r;
    }

    r = fflush(stdout);

    for (f = *__ofl_lock(); f; f = f->next) {
        FLOCK(f);
        if (f->wpos > f->wbase)
            r |= __fflush_unlocked(f);
        FUNLOCK(f);
    }
    __ofl_unlock();

    return r;
}

weak_alias(__fflush_unlocked, fflush_unlocked);