ceph/src/os/fs/aio.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #include "aio.h"
   5
   6 #if defined(HAVE_LIBAIO)
   7
   8 int aio_queue_t::submit(aio_t &aio, int *retries)
   9 {
  10   // 2^16 * 125us = ~8 seconds, so max sleep is ~16 seconds
  11   int attempts = 16;
  12   int delay = 125;
  13   iocb *piocb = &aio.iocb;
  14   while (true) {
  15     int r = io_submit(ctx, 1, &piocb);
  16     if (r < 0) {
  17       if (r == -EAGAIN && attempts-- > 0) {
  18         usleep(delay);
  19         delay *= 2;
  20         (*retries)++;
  21         continue;
  22       }
  23       return r;
  24     }
  25     assert(r == 1);
  26     break;
  27   }
  28   return 0;
  29 }
  30
  31 int aio_queue_t::get_next_completed(int timeout_ms, aio_t **paio, int max)
  32 {
  33   io_event event[max];
  34   struct timespec t = {
  35     timeout_ms / 1000,
  36     (timeout_ms % 1000) * 1000 * 1000
  37   };
  38
  39   int r = 0;
  40   do {
  41     r = io_getevents(ctx, 1, max, event, &t);
  42   } while (r == -EINTR);
  43
  44   for (int i=0; i<r; ++i) {
  45     paio[i] = (aio_t *)event[i].obj;
  46     paio[i]->rval = event[i].res;
  47   }
  48   return r;
  49 }
  50
  51 #endif