1 files changed, 124 insertions, 0 deletions
diff --git a/src/blk/aio/aio.cc b/src/blk/aio/aio.cc
new file mode 100644
index 000000000..00a12bfd1
--- /dev/null
+++ b/src/blk/aio/aio.cc
@@ -0,0 +1,124 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include <algorithm>
+#include "aio.h"
+
+std::ostream& operator<<(std::ostream& os, const aio_t& aio)
+{
+  unsigned i = 0;
+  os << "aio: ";
+  for (auto& iov : aio.iov) {
+    os << "\n [" << i++ << "] 0x"
+       << std::hex << iov.iov_base << "~" << iov.iov_len << std::dec;
+  }
+  return os;
+}
+
+int aio_queue_t::submit_batch(aio_iter begin, aio_iter end, 
+			      uint16_t aios_size, void *priv, 
+			      int *retries)
+{
+  // 2^16 * 125us = ~8 seconds, so max sleep is ~16 seconds
+  int attempts = 16;
+  int delay = 125;
+  int r;
+
+  aio_iter cur = begin;
+  struct aio_t *piocb[aios_size];
+  int left = 0;
+  while (cur != end) {
+    cur->priv = priv;
+    *(piocb+left) = &(*cur);
+    ++left;
+    ++cur;
+  }
+  ceph_assert(aios_size >= left);
+  int done = 0;
+  while (left > 0) {
+#if defined(HAVE_LIBAIO)
+    r = io_submit(ctx, std::min(left, max_iodepth), (struct iocb**)(piocb + done));
+#elif defined(HAVE_POSIXAIO)
+    if (piocb[done]->n_aiocb == 1) {
+      // TODO: consider batching multiple reads together with lio_listio
+      piocb[done]->aio.aiocb.aio_sigevent.sigev_notify = SIGEV_KEVENT;
+      piocb[done]->aio.aiocb.aio_sigevent.sigev_notify_kqueue = ctx;
+      piocb[done]->aio.aiocb.aio_sigevent.sigev_value.sival_ptr = piocb[done];
+      r = aio_read(&piocb[done]->aio.aiocb);
+    } else {
+      struct sigevent sev;
+      sev.sigev_notify = SIGEV_KEVENT;
+      sev.sigev_notify_kqueue = ctx;
+      sev.sigev_value.sival_ptr = piocb[done];
+      r = lio_listio(LIO_NOWAIT, &piocb[done]->aio.aiocbp, piocb[done]->n_aiocb, &sev);
+    }
+#endif
+    if (r < 0) {
+      if (r == -EAGAIN && attempts-- > 0) {
+	usleep(delay);
+	delay *= 2;
+	(*retries)++;
+	continue;
+      }
+      return r;
+    }
+    ceph_assert(r > 0);
+    done += r;
+    left -= r;
+    attempts = 16;
+    delay = 125;
+  }
+  return done;
+}
+
+int aio_queue_t::get_next_completed(int timeout_ms, aio_t **paio, int max)
+{
+#if defined(HAVE_LIBAIO)
+  io_event events[max];
+#elif defined(HAVE_POSIXAIO)
+  struct kevent events[max];
+#endif
+  struct timespec t = {
+    timeout_ms / 1000,
+    (timeout_ms % 1000) * 1000 * 1000
+  };
+
+  int r = 0;
+  do {
+#if defined(HAVE_LIBAIO)
+    r = io_getevents(ctx, 1, max, events, &t);
+#elif defined(HAVE_POSIXAIO)
+    r = kevent(ctx, NULL, 0, events, max, &t);
+    if (r < 0)
+      r = -errno;
+#endif
+  } while (r == -EINTR);
+
+  for (int i=0; i<r; ++i) {
+#if defined(HAVE_LIBAIO)
+    paio[i] = (aio_t *)events[i].obj;
+    paio[i]->rval = events[i].res;
+#else
+    paio[i] = (aio_t*)events[i].udata;
+    if (paio[i]->n_aiocb == 1) {
+      paio[i]->rval = aio_return(&paio[i]->aio.aiocb);
+    } else {
+      // Emulate the return value of pwritev.  I can't find any documentation
+      // for what the value of io_event.res is supposed to be.  I'm going to
+      // assume that it's just like pwritev/preadv/pwrite/pread.
+      paio[i]->rval = 0;
+      for (int j = 0; j < paio[i]->n_aiocb; j++) {
+	int res = aio_return(&paio[i]->aio.aiocbp[j]);
+	if (res < 0) {
+	  paio[i]->rval = res;
+	  break;
+	} else {
+	  paio[i]->rval += res;
+	}
+      }
+      free(paio[i]->aio.aiocbp);
+    }
+#endif
+  }
+  return r;
+}