source: MondoRescue/branches/2.2.9/mindi-busybox/procps/nmeter.c@ 2725

/*
 * Licensed under GPLv2, see file LICENSE in this source tree.
 *
 * Based on nanotop.c from floppyfw project
 *
 * Contact me: vda.linux@googlemail.com
 */

//TODO:
// simplify code
// /proc/locks
// /proc/stat:
// disk_io: (3,0):(22272,17897,410702,4375,54750)
// btime 1059401962
//TODO: use sysinfo libc call/syscall, if appropriate
// (faster than open/read/close):
// sysinfo({uptime=15017, loads=[5728, 15040, 16480]
//  totalram=2107416576, freeram=211525632, sharedram=0, bufferram=157204480}
//  totalswap=134209536, freeswap=134209536, procs=157})

#include "libbb.h"

typedef unsigned long long ullong;

enum {  /* Preferably use powers of 2 */
    PROC_MIN_FILE_SIZE = 256,
    PROC_MAX_FILE_SIZE = 16 * 1024,
};

typedef struct proc_file {
    char *file;
    int file_sz;
    smallint last_gen;
} proc_file;

static const char *const proc_name[] = {
    "stat",     // Must match the order of proc_file's!
    "loadavg",
    "net/dev",
    "meminfo",
    "diskstats",
    "sys/fs/file-nr"
};

struct globals {
    // Sample generation flip-flop
    smallint gen;
    // Linux 2.6? (otherwise assumes 2.4)
    smallint is26;
    // 1 if sample delay is not an integer fraction of a second
    smallint need_seconds;
    char *cur_outbuf;
    const char *final_str;
    int delta;
    int deltanz;
    struct timeval tv;
#define first_proc_file proc_stat
    proc_file proc_stat;    // Must match the order of proc_name's!
    proc_file proc_loadavg;
    proc_file proc_net_dev;
    proc_file proc_meminfo;
    proc_file proc_diskstats;
    proc_file proc_sys_fs_filenr;
};
#define G (*ptr_to_globals)
#define gen                (G.gen               )
#define is26               (G.is26              )
#define need_seconds       (G.need_seconds      )
#define cur_outbuf         (G.cur_outbuf        )
#define final_str          (G.final_str         )
#define delta              (G.delta             )
#define deltanz            (G.deltanz           )
#define tv                 (G.tv                )
#define proc_stat          (G.proc_stat         )
#define proc_loadavg       (G.proc_loadavg      )
#define proc_net_dev       (G.proc_net_dev      )
#define proc_meminfo       (G.proc_meminfo      )
#define proc_diskstats     (G.proc_diskstats    )
#define proc_sys_fs_filenr (G.proc_sys_fs_filenr)
#define INIT_G() do { \
    SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
    cur_outbuf = outbuf; \
    final_str = "\n"; \
    deltanz = delta = 1000000; \
} while (0)

// We depend on this being a char[], not char* - we take sizeof() of it
#define outbuf bb_common_bufsiz1

static inline void reset_outbuf(void)
{
    cur_outbuf = outbuf;
}

static inline int outbuf_count(void)
{
    return cur_outbuf - outbuf;
}

static void print_outbuf(void)
{
    int sz = cur_outbuf - outbuf;
    if (sz > 0) {
        xwrite(STDOUT_FILENO, outbuf, sz);
        cur_outbuf = outbuf;
    }
}

static void put(const char *s)
{
    int sz = strlen(s);
    if (sz > outbuf + sizeof(outbuf) - cur_outbuf)
        sz = outbuf + sizeof(outbuf) - cur_outbuf;
    memcpy(cur_outbuf, s, sz);
    cur_outbuf += sz;
}

static void put_c(char c)
{
    if (cur_outbuf < outbuf + sizeof(outbuf))
        *cur_outbuf++ = c;
}

static void put_question_marks(int count)
{
    while (count--)
        put_c('?');
}

static void readfile_z(proc_file *pf, const char* fname)
{
// open_read_close() will do two reads in order to be sure we are at EOF,
// and we don't need/want that.
    int fd;
    int sz, rdsz;
    char *buf;

    sz = pf->file_sz;
    buf = pf->file;
    if (!buf) {
        buf = xmalloc(PROC_MIN_FILE_SIZE);
        sz = PROC_MIN_FILE_SIZE;
    }
 again:
    fd = xopen(fname, O_RDONLY);
    buf[0] = '\0';
    rdsz = read(fd, buf, sz-1);
    close(fd);
    if (rdsz > 0) {
        if (rdsz == sz-1 && sz < PROC_MAX_FILE_SIZE) {
            sz *= 2;
            buf = xrealloc(buf, sz);
            goto again;
        }
        buf[rdsz] = '\0';
    }
    pf->file_sz = sz;
    pf->file = buf;
}

static const char* get_file(proc_file *pf)
{
    if (pf->last_gen != gen) {
        pf->last_gen = gen;
        readfile_z(pf, proc_name[pf - &first_proc_file]);
    }
    return pf->file;
}

static ullong read_after_slash(const char *p)
{
    p = strchr(p, '/');
    if (!p) return 0;
    return strtoull(p+1, NULL, 10);
}

enum conv_type { conv_decimal, conv_slash };

// Reads decimal values from line. Values start after key, for example:
// "cpu  649369 0 341297 4336769..." - key is "cpu" here.
// Values are stored in vec[]. arg_ptr has list of positions
// we are interested in: for example: 1,2,5 - we want 1st, 2nd and 5th value.
static int vrdval(const char* p, const char* key,
    enum conv_type conv, ullong *vec, va_list arg_ptr)
{
    int indexline;
    int indexnext;

    p = strstr(p, key);
    if (!p) return 1;

    p += strlen(key);
    indexline = 1;
    indexnext = va_arg(arg_ptr, int);
    while (1) {
        while (*p == ' ' || *p == '\t') p++;
        if (*p == '\n' || *p == '\0') break;

        if (indexline == indexnext) { // read this value
            *vec++ = conv==conv_decimal ?
                strtoull(p, NULL, 10) :
                read_after_slash(p);
            indexnext = va_arg(arg_ptr, int);
        }
        while (*p > ' ') p++; // skip over value
        indexline++;
    }
    return 0;
}

// Parses files with lines like "cpu0 21727 0 15718 1813856 9461 10485 0 0":
// rdval(file_contents, "string_to_find", result_vector, value#, value#...)
// value# start with 1
static int rdval(const char* p, const char* key, ullong *vec, ...)
{
    va_list arg_ptr;
    int result;

    va_start(arg_ptr, vec);
    result = vrdval(p, key, conv_decimal, vec, arg_ptr);
    va_end(arg_ptr);

    return result;
}

// Parses files with lines like "... ... ... 3/148 ...."
static int rdval_loadavg(const char* p, ullong *vec, ...)
{
    va_list arg_ptr;
    int result;

    va_start(arg_ptr, vec);
    result = vrdval(p, "", conv_slash, vec, arg_ptr);
    va_end(arg_ptr);

    return result;
}

// Parses /proc/diskstats
//   1  2 3   4  5        6(rd)  7      8     9     10(wr) 11     12 13     14
//   3  0 hda 51292 14441 841783 926052 25717 79650 843256 3029804 0 148459 3956933
//   3  1 hda1 0 0 0 0 <- ignore if only 4 fields
static int rdval_diskstats(const char* p, ullong *vec)
{
    ullong rd = rd; // for compiler
    int indexline = 0;
    vec[0] = 0;
    vec[1] = 0;
    while (1) {
        indexline++;
        while (*p == ' ' || *p == '\t') p++;
        if (*p == '\0') break;
        if (*p == '\n') {
            indexline = 0;
            p++;
            continue;
        }
        if (indexline == 6) {
            rd = strtoull(p, NULL, 10);
        } else if (indexline == 10) {
            vec[0] += rd;  // TODO: *sectorsize (don't know how to find out sectorsize)
            vec[1] += strtoull(p, NULL, 10);
            while (*p != '\n' && *p != '\0') p++;
            continue;
        }
        while (*p > ' ') p++; // skip over value
    }
    return 0;
}

static void scale(ullong ul)
{
    char buf[5];

    /* see http://en.wikipedia.org/wiki/Tera */
    smart_ulltoa4(ul, buf, " kmgtpezy");
    buf[4] = '\0';
    put(buf);
}


#define S_STAT(a) \
typedef struct a { \
    struct s_stat *next; \
    void (*collect)(struct a *s) FAST_FUNC; \
    const char *label;
#define S_STAT_END(a) } a;

S_STAT(s_stat)
S_STAT_END(s_stat)

static void FAST_FUNC collect_literal(s_stat *s UNUSED_PARAM)
{
}

static s_stat* init_literal(void)
{
    s_stat *s = xzalloc(sizeof(*s));
    s->collect = collect_literal;
    return (s_stat*)s;
}

static s_stat* init_delay(const char *param)
{
    delta = strtoul(param, NULL, 0) * 1000; /* param can be "" */
    deltanz = delta > 0 ? delta : 1;
    need_seconds = (1000000%deltanz) != 0;
    return NULL;
}

static s_stat* init_cr(const char *param UNUSED_PARAM)
{
    final_str = "\r";
    return (s_stat*)0;
}


//     user nice system idle  iowait irq  softirq (last 3 only in 2.6)
//cpu  649369 0 341297 4336769 11640 7122 1183
//cpuN 649369 0 341297 4336769 11640 7122 1183
enum { CPU_FIELDCNT = 7 };
S_STAT(cpu_stat)
    ullong old[CPU_FIELDCNT];
    int bar_sz;
    char *bar;
S_STAT_END(cpu_stat)


static void FAST_FUNC collect_cpu(cpu_stat *s)
{
    ullong data[CPU_FIELDCNT] = { 0, 0, 0, 0, 0, 0, 0 };
    unsigned frac[CPU_FIELDCNT] = { 0, 0, 0, 0, 0, 0, 0 };
    ullong all = 0;
    int norm_all = 0;
    int bar_sz = s->bar_sz;
    char *bar = s->bar;
    int i;

    if (rdval(get_file(&proc_stat), "cpu ", data, 1, 2, 3, 4, 5, 6, 7)) {
        put_question_marks(bar_sz);
        return;
    }

    for (i = 0; i < CPU_FIELDCNT; i++) {
        ullong old = s->old[i];
        if (data[i] < old) old = data[i];       //sanitize
        s->old[i] = data[i];
        all += (data[i] -= old);
    }

    if (all) {
        for (i = 0; i < CPU_FIELDCNT; i++) {
            ullong t = bar_sz * data[i];
            norm_all += data[i] = t / all;
            frac[i] = t % all;
        }

        while (norm_all < bar_sz) {
            unsigned max = frac[0];
            int pos = 0;
            for (i = 1; i < CPU_FIELDCNT; i++) {
                if (frac[i] > max) max = frac[i], pos = i;
            }
            frac[pos] = 0;  //avoid bumping up same value twice
            data[pos]++;
            norm_all++;
        }

        memset(bar, '.', bar_sz);
        memset(bar, 'S', data[2]); bar += data[2]; //sys
        memset(bar, 'U', data[0]); bar += data[0]; //usr
        memset(bar, 'N', data[1]); bar += data[1]; //nice
        memset(bar, 'D', data[4]); bar += data[4]; //iowait
        memset(bar, 'I', data[5]); bar += data[5]; //irq
        memset(bar, 'i', data[6]); bar += data[6]; //softirq
    } else {
        memset(bar, '?', bar_sz);
    }
    put(s->bar);
}


static s_stat* init_cpu(const char *param)
{
    int sz;
    cpu_stat *s = xzalloc(sizeof(*s));
    s->collect = collect_cpu;
    sz = strtoul(param, NULL, 0); /* param can be "" */
    if (sz < 10) sz = 10;
    if (sz > 1000) sz = 1000;
    s->bar = xzalloc(sz+1);
    /*s->bar[sz] = '\0'; - xzalloc did it */
    s->bar_sz = sz;
    return (s_stat*)s;
}


S_STAT(int_stat)
    ullong old;
    int no;
S_STAT_END(int_stat)

static void FAST_FUNC collect_int(int_stat *s)
{
    ullong data[1];
    ullong old;

    if (rdval(get_file(&proc_stat), "intr", data, s->no)) {
        put_question_marks(4);
        return;
    }

    old = s->old;
    if (data[0] < old) old = data[0];       //sanitize
    s->old = data[0];
    scale(data[0] - old);
}

static s_stat* init_int(const char *param)
{
    int_stat *s = xzalloc(sizeof(*s));
    s->collect = collect_int;
    if (param[0] == '\0') {
        s->no = 1;
    } else {
        int n = xatoi_positive(param);
        s->no = n + 2;
    }
    return (s_stat*)s;
}


S_STAT(ctx_stat)
    ullong old;
S_STAT_END(ctx_stat)

static void FAST_FUNC collect_ctx(ctx_stat *s)
{
    ullong data[1];
    ullong old;

    if (rdval(get_file(&proc_stat), "ctxt", data, 1)) {
        put_question_marks(4);
        return;
    }

    old = s->old;
    if (data[0] < old) old = data[0];       //sanitize
    s->old = data[0];
    scale(data[0] - old);
}

static s_stat* init_ctx(const char *param UNUSED_PARAM)
{
    ctx_stat *s = xzalloc(sizeof(*s));
    s->collect = collect_ctx;
    return (s_stat*)s;
}


S_STAT(blk_stat)
    const char* lookfor;
    ullong old[2];
S_STAT_END(blk_stat)

static void FAST_FUNC collect_blk(blk_stat *s)
{
    ullong data[2];
    int i;

    if (is26) {
        i = rdval_diskstats(get_file(&proc_diskstats), data);
    } else {
        i = rdval(get_file(&proc_stat), s->lookfor, data, 1, 2);
        // Linux 2.4 reports bio in Kbytes, convert to sectors:
        data[0] *= 2;
        data[1] *= 2;
    }
    if (i) {
        put_question_marks(9);
        return;
    }

    for (i=0; i<2; i++) {
        ullong old = s->old[i];
        if (data[i] < old) old = data[i];       //sanitize
        s->old[i] = data[i];
        data[i] -= old;
    }
    scale(data[0]*512); // TODO: *sectorsize
    put_c(' ');
    scale(data[1]*512);
}

static s_stat* init_blk(const char *param UNUSED_PARAM)
{
    blk_stat *s = xzalloc(sizeof(*s));
    s->collect = collect_blk;
    s->lookfor = "page";
    return (s_stat*)s;
}


S_STAT(fork_stat)
    ullong old;
S_STAT_END(fork_stat)

static void FAST_FUNC collect_thread_nr(fork_stat *s UNUSED_PARAM)
{
    ullong data[1];

    if (rdval_loadavg(get_file(&proc_loadavg), data, 4)) {
        put_question_marks(4);
        return;
    }
    scale(data[0]);
}

static void FAST_FUNC collect_fork(fork_stat *s)
{
    ullong data[1];
    ullong old;

    if (rdval(get_file(&proc_stat), "processes", data, 1)) {
        put_question_marks(4);
        return;
    }

    old = s->old;
    if (data[0] < old) old = data[0];   //sanitize
    s->old = data[0];
    scale(data[0] - old);
}

static s_stat* init_fork(const char *param)
{
    fork_stat *s = xzalloc(sizeof(*s));
    if (*param == 'n') {
        s->collect = collect_thread_nr;
    } else {
        s->collect = collect_fork;
    }
    return (s_stat*)s;
}


S_STAT(if_stat)
    ullong old[4];
    const char *device;
    char *device_colon;
S_STAT_END(if_stat)

static void FAST_FUNC collect_if(if_stat *s)
{
    ullong data[4];
    int i;

    if (rdval(get_file(&proc_net_dev), s->device_colon, data, 1, 3, 9, 11)) {
        put_question_marks(10);
        return;
    }

    for (i=0; i<4; i++) {
        ullong old = s->old[i];
        if (data[i] < old) old = data[i];       //sanitize
        s->old[i] = data[i];
        data[i] -= old;
    }
    put_c(data[1] ? '*' : ' ');
    scale(data[0]);
    put_c(data[3] ? '*' : ' ');
    scale(data[2]);
}

static s_stat* init_if(const char *device)
{
    if_stat *s = xzalloc(sizeof(*s));

    if (!device || !device[0])
        bb_show_usage();
    s->collect = collect_if;

    s->device = device;
    s->device_colon = xasprintf("%s:", device);
    return (s_stat*)s;
}


S_STAT(mem_stat)
    char opt;
S_STAT_END(mem_stat)

// "Memory" value should not include any caches.
// IOW: neither "ls -laR /" nor heavy read/write activity
//      should affect it. We'd like to also include any
//      long-term allocated kernel-side mem, but it is hard
//      to figure out. For now, bufs, cached & slab are
//      counted as "free" memory
//2.6.16:
//MemTotal:       773280 kB
//MemFree:         25912 kB - genuinely free
//Buffers:        320672 kB - cache
//Cached:         146396 kB - cache
//SwapCached:          0 kB
//Active:         183064 kB
//Inactive:       356892 kB
//HighTotal:           0 kB
//HighFree:            0 kB
//LowTotal:       773280 kB
//LowFree:         25912 kB
//SwapTotal:      131064 kB
//SwapFree:       131064 kB
//Dirty:              48 kB
//Writeback:           0 kB
//Mapped:          96620 kB
//Slab:           200668 kB - takes 7 Mb on my box fresh after boot,
//                            but includes dentries and inodes
//                            (== can take arbitrary amount of mem)
//CommitLimit:    517704 kB
//Committed_AS:   236776 kB
//PageTables:       1248 kB
//VmallocTotal:   516052 kB
//VmallocUsed:      3852 kB
//VmallocChunk:   512096 kB
//HugePages_Total:     0
//HugePages_Free:      0
//Hugepagesize:     4096 kB
static void FAST_FUNC collect_mem(mem_stat *s)
{
    ullong m_total = 0;
    ullong m_free = 0;
    ullong m_bufs = 0;
    ullong m_cached = 0;
    ullong m_slab = 0;

    if (rdval(get_file(&proc_meminfo), "MemTotal:", &m_total, 1)) {
        put_question_marks(4);
        return;
    }
    if (s->opt == 't') {
        scale(m_total << 10);
        return;
    }

    if (rdval(proc_meminfo.file, "MemFree:", &m_free  , 1)
     || rdval(proc_meminfo.file, "Buffers:", &m_bufs  , 1)
     || rdval(proc_meminfo.file, "Cached:",  &m_cached, 1)
     || rdval(proc_meminfo.file, "Slab:",    &m_slab  , 1)
    ) {
        put_question_marks(4);
        return;
    }

    m_free += m_bufs + m_cached + m_slab;
    switch (s->opt) {
    case 'f':
        scale(m_free << 10); break;
    default:
        scale((m_total - m_free) << 10); break;
    }
}

static s_stat* init_mem(const char *param)
{
    mem_stat *s = xzalloc(sizeof(*s));
    s->collect = collect_mem;
    s->opt = param[0];
    return (s_stat*)s;
}


S_STAT(swp_stat)
S_STAT_END(swp_stat)

static void FAST_FUNC collect_swp(swp_stat *s UNUSED_PARAM)
{
    ullong s_total[1];
    ullong s_free[1];
    if (rdval(get_file(&proc_meminfo), "SwapTotal:", s_total, 1)
     || rdval(proc_meminfo.file,       "SwapFree:" , s_free,  1)
    ) {
        put_question_marks(4);
        return;
    }
    scale((s_total[0]-s_free[0]) << 10);
}

static s_stat* init_swp(const char *param UNUSED_PARAM)
{
    swp_stat *s = xzalloc(sizeof(*s));
    s->collect = collect_swp;
    return (s_stat*)s;
}


S_STAT(fd_stat)
S_STAT_END(fd_stat)

static void FAST_FUNC collect_fd(fd_stat *s UNUSED_PARAM)
{
    ullong data[2];

    if (rdval(get_file(&proc_sys_fs_filenr), "", data, 1, 2)) {
        put_question_marks(4);
        return;
    }

    scale(data[0] - data[1]);
}

static s_stat* init_fd(const char *param UNUSED_PARAM)
{
    fd_stat *s = xzalloc(sizeof(*s));
    s->collect = collect_fd;
    return (s_stat*)s;
}


S_STAT(time_stat)
    int prec;
    int scale;
S_STAT_END(time_stat)

static void FAST_FUNC collect_time(time_stat *s)
{
    char buf[sizeof("12:34:56.123456")];
    struct tm* tm;
    int us = tv.tv_usec + s->scale/2;
    time_t t = tv.tv_sec;

    if (us >= 1000000) {
        t++;
        us -= 1000000;
    }
    tm = localtime(&t);

    sprintf(buf, "%02d:%02d:%02d", tm->tm_hour, tm->tm_min, tm->tm_sec);
    if (s->prec)
        sprintf(buf+8, ".%0*d", s->prec, us / s->scale);
    put(buf);
}

static s_stat* init_time(const char *param)
{
    int prec;
    time_stat *s = xzalloc(sizeof(*s));

    s->collect = collect_time;
    prec = param[0] - '0';
    if (prec < 0) prec = 0;
    else if (prec > 6) prec = 6;
    s->prec = prec;
    s->scale = 1;
    while (prec++ < 6)
        s->scale *= 10;
    return (s_stat*)s;
}

static void FAST_FUNC collect_info(s_stat *s)
{
    gen ^= 1;
    while (s) {
        put(s->label);
        s->collect(s);
        s = s->next;
    }
}


typedef s_stat* init_func(const char *param);

static const char options[] ALIGN1 = "ncmsfixptbdr";
static init_func *const init_functions[] = {
    init_if,
    init_cpu,
    init_mem,
    init_swp,
    init_fd,
    init_int,
    init_ctx,
    init_fork,
    init_time,
    init_blk,
    init_delay,
    init_cr
};

int nmeter_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int nmeter_main(int argc UNUSED_PARAM, char **argv)
{
    char buf[32];
    s_stat *first = NULL;
    s_stat *last = NULL;
    s_stat *s;
    char *cur, *prev;

    INIT_G();

    xchdir("/proc");

    if (!argv[1])
        bb_show_usage();

    if (open_read_close("version", buf, sizeof(buf)-1) > 0) {
        buf[sizeof(buf)-1] = '\0';
        is26 = (strstr(buf, " 2.4.") == NULL);
    }

    // Can use argv[1] directly, but this will mess up
    // parameters as seen by e.g. ps. Making a copy...
    cur = xstrdup(argv[1]);
    while (1) {
        char *param, *p;
        prev = cur;
 again:
        cur = strchr(cur, '%');
        if (!cur)
            break;
        if (cur[1] == '%') {    // %%
            overlapping_strcpy(cur, cur + 1);
            cur++;
            goto again;
        }
        *cur++ = '\0';      // overwrite %
        if (cur[0] == '[') {
            // format: %[foptstring]
            cur++;
            p = strchr(options, cur[0]);
            param = cur+1;
            while (cur[0] != ']') {
                if (!cur[0])
                    bb_show_usage();
                cur++;
            }
            *cur++ = '\0';  // overwrite [
        } else {
            // format: %NNNNNNf
            param = cur;
            while (cur[0] >= '0' && cur[0] <= '9')
                cur++;
            if (!cur[0])
                bb_show_usage();
            p = strchr(options, cur[0]);
            *cur++ = '\0';  // overwrite format char
        }
        if (!p)
            bb_show_usage();
        s = init_functions[p-options](param);
        if (s) {
            s->label = prev;
            /*s->next = NULL; - all initXXX funcs use xzalloc */
            if (!first)
                first = s;
            else
                last->next = s;
            last = s;
        } else {
            // %NNNNd or %r option. remove it from string
            strcpy(prev + strlen(prev), cur);
            cur = prev;
        }
    }
    if (prev[0]) {
        s = init_literal();
        s->label = prev;
        /*s->next = NULL; - all initXXX funcs use xzalloc */
        if (!first)
            first = s;
        else
            last->next = s;
        last = s;
    }

    // Generate first samples but do not print them, they're bogus
    collect_info(first);
    reset_outbuf();
    if (delta >= 0) {
        gettimeofday(&tv, NULL);
        usleep(delta > 1000000 ? 1000000 : delta - tv.tv_usec%deltanz);
    }

    while (1) {
        gettimeofday(&tv, NULL);
        collect_info(first);
        put(final_str);
        print_outbuf();

        // Negative delta -> no usleep at all
        // This will hog the CPU but you can have REALLY GOOD
        // time resolution ;)
        // TODO: detect and avoid useless updates
        // (like: nothing happens except time)
        if (delta >= 0) {
            int rem;
            // can be commented out, will sacrifice sleep time precision a bit
            gettimeofday(&tv, NULL);
            if (need_seconds)
                rem = delta - ((ullong)tv.tv_sec*1000000 + tv.tv_usec) % deltanz;
            else
                rem = delta - tv.tv_usec%deltanz;
            // Sometimes kernel wakes us up just a tiny bit earlier than asked
            // Do not go to very short sleep in this case
            if (rem < delta/128) {
                rem += delta;
            }
            usleep(rem);
        }
    }

    /*return 0;*/
}