ceph/src/librbd/AsyncObjectThrottle.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 #include "librbd/AsyncObjectThrottle.h"
   4 #include "common/RWLock.h"
   5 #include "common/WorkQueue.h"
   6 #include "librbd/AsyncRequest.h"
   7 #include "librbd/ImageCtx.h"
   8 #include "librbd/Utils.h"
   9
  10 namespace librbd
  11 {
  12
  13 template <typename T>
  14 AsyncObjectThrottle<T>::AsyncObjectThrottle(
  15     const AsyncRequest<T>* async_request, T &image_ctx,
  16     const ContextFactory& context_factory, Context *ctx,
  17     ProgressContext *prog_ctx, uint64_t object_no, uint64_t end_object_no)
  18   : m_lock(util::unique_lock_name("librbd::AsyncThrottle::m_lock", this)),
  19     m_async_request(async_request), m_image_ctx(image_ctx),
  20     m_context_factory(context_factory), m_ctx(ctx), m_prog_ctx(prog_ctx),
  21     m_object_no(object_no), m_end_object_no(end_object_no), m_current_ops(0),
  22     m_ret(0)
  23 {
  24 }
  25
  26 template <typename T>
  27 void AsyncObjectThrottle<T>::start_ops(uint64_t max_concurrent) {
  28   ceph_assert(m_image_ctx.owner_lock.is_locked());
  29   bool complete;
  30   {
  31     Mutex::Locker l(m_lock);
  32     for (uint64_t i = 0; i < max_concurrent; ++i) {
  33       start_next_op();
  34       if (m_ret < 0 && m_current_ops == 0) {
  35         break;
  36       }
  37     }
  38     complete = (m_current_ops == 0);
  39   }
  40   if (complete) {
  41     // avoid re-entrant callback
  42     m_image_ctx.op_work_queue->queue(m_ctx, m_ret);
  43     delete this;
  44   }
  45 }
  46
  47 template <typename T>
  48 void AsyncObjectThrottle<T>::finish_op(int r) {
  49   bool complete;
  50   {
  51     RWLock::RLocker owner_locker(m_image_ctx.owner_lock);
  52     Mutex::Locker locker(m_lock);
  53     --m_current_ops;
  54     if (r < 0 && r != -ENOENT && m_ret == 0) {
  55       m_ret = r;
  56     }
  57
  58     start_next_op();
  59     complete = (m_current_ops == 0);
  60   }
  61   if (complete) {
  62     m_ctx->complete(m_ret);
  63     delete this;
  64   }
  65 }
  66
  67 template <typename T>
  68 void AsyncObjectThrottle<T>::start_next_op() {
  69   bool done = false;
  70   while (!done) {
  71     if (m_async_request != NULL && m_async_request->is_canceled() &&
  72         m_ret == 0) {
  73       // allow in-flight ops to complete, but don't start new ops
  74       m_ret = -ERESTART;
  75       return;
  76     } else if (m_ret != 0 || m_object_no >= m_end_object_no) {
  77       return;
  78     }
  79
  80     uint64_t ono = m_object_no++;
  81     C_AsyncObjectThrottle<T> *ctx = m_context_factory(*this, ono);
  82
  83     int r = ctx->send();
  84     if (r < 0) {
  85       m_ret = r;
  86       delete ctx;
  87       return;
  88     } else if (r > 0) {
  89       // op completed immediately
  90       delete ctx;
  91     } else {
  92       ++m_current_ops;
  93       done = true;
  94     }
  95     if (m_prog_ctx != NULL) {
  96       m_prog_ctx->update_progress(ono, m_end_object_no);
  97     }
  98   }
  99 }
 100
 101 } // namespace librbd
 102
 103 #ifndef TEST_F
 104 template class librbd::AsyncObjectThrottle<librbd::ImageCtx>;
 105 #endif