initial code repo

[stor4nfv.git] / src / ceph / src / journal / FutureImpl.cc

diff --git a/src/ceph/src/journal/FutureImpl.cc b/src/ceph/src/journal/FutureImpl.cc
new file mode 100644 (file)
index 0000000..e46a3c9
--- /dev/null
+++ b/src/ceph/src/journal/FutureImpl.cc
@@ -0,0 +1,174 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "journal/FutureImpl.h"
+#include "journal/Utils.h"
+
+namespace journal {
+
+FutureImpl::FutureImpl(uint64_t tag_tid, uint64_t entry_tid,
+                       uint64_t commit_tid)
+  : RefCountedObject(NULL, 0), m_tag_tid(tag_tid), m_entry_tid(entry_tid),
+    m_commit_tid(commit_tid),
+    m_lock("FutureImpl::m_lock", false, false), m_safe(false),
+    m_consistent(false), m_return_value(0), m_flush_state(FLUSH_STATE_NONE),
+    m_consistent_ack(this) {
+}
+
+void FutureImpl::init(const FutureImplPtr &prev_future) {
+  // chain ourself to the prior future (if any) to that we known when the
+  // journal is consistent
+  if (prev_future) {
+    m_prev_future = prev_future;
+    m_prev_future->wait(&m_consistent_ack);
+  } else {
+    m_consistent_ack.complete(0);
+  }
+}
+
+void FutureImpl::flush(Context *on_safe) {
+
+  bool complete;
+  FlushHandlers flush_handlers;
+  FutureImplPtr prev_future;
+  {
+    Mutex::Locker locker(m_lock);
+    complete = (m_safe && m_consistent);
+    if (!complete) {
+      if (on_safe != nullptr) {
+        m_contexts.push_back(on_safe);
+      }
+
+      prev_future = prepare_flush(&flush_handlers, m_lock);
+    }
+  }
+
+  // instruct prior futures to flush as well
+  while (prev_future) {
+    prev_future = prev_future->prepare_flush(&flush_handlers);
+  }
+
+  if (complete && on_safe != NULL) {
+    on_safe->complete(m_return_value);
+  } else if (!flush_handlers.empty()) {
+    // attached to journal object -- instruct it to flush all entries through
+    // this one.  possible to become detached while lock is released, so flush
+    // will be re-requested by the object if it doesn't own the future
+    for (auto &pair : flush_handlers) {
+      pair.first->flush(pair.second);
+    }
+  }
+}
+
+FutureImplPtr FutureImpl::prepare_flush(FlushHandlers *flush_handlers) {
+  Mutex::Locker locker(m_lock);
+  return prepare_flush(flush_handlers, m_lock);
+}
+
+FutureImplPtr FutureImpl::prepare_flush(FlushHandlers *flush_handlers,
+                                        Mutex &lock) {
+  assert(m_lock.is_locked());
+
+  if (m_flush_state == FLUSH_STATE_NONE) {
+    m_flush_state = FLUSH_STATE_REQUESTED;
+
+    if (m_flush_handler && flush_handlers->count(m_flush_handler) == 0) {
+      flush_handlers->insert({m_flush_handler, this});
+    }
+  }
+  return m_prev_future;
+}
+
+void FutureImpl::wait(Context *on_safe) {
+  assert(on_safe != NULL);
+  {
+    Mutex::Locker locker(m_lock);
+    if (!m_safe || !m_consistent) {
+      m_contexts.push_back(on_safe);
+      return;
+    }
+  }
+
+  on_safe->complete(m_return_value);
+}
+
+bool FutureImpl::is_complete() const {
+  Mutex::Locker locker(m_lock);
+  return m_safe && m_consistent;
+}
+
+int FutureImpl::get_return_value() const {
+  Mutex::Locker locker(m_lock);
+  assert(m_safe && m_consistent);
+  return m_return_value;
+}
+
+bool FutureImpl::attach(const FlushHandlerPtr &flush_handler) {
+  Mutex::Locker locker(m_lock);
+  assert(!m_flush_handler);
+  m_flush_handler = flush_handler;
+  return m_flush_state != FLUSH_STATE_NONE;
+}
+
+void FutureImpl::safe(int r) {
+  m_lock.Lock();
+  assert(!m_safe);
+  m_safe = true;
+  if (m_return_value == 0) {
+    m_return_value = r;
+  }
+
+  m_flush_handler.reset();
+  if (m_consistent) {
+    finish_unlock();
+  } else {
+    m_lock.Unlock();
+  }
+}
+
+void FutureImpl::consistent(int r) {
+  m_lock.Lock();
+  assert(!m_consistent);
+  m_consistent = true;
+  m_prev_future.reset();
+  if (m_return_value == 0) {
+    m_return_value = r;
+  }
+
+  if (m_safe) {
+    finish_unlock();
+  } else {
+    m_lock.Unlock();
+  }
+}
+
+void FutureImpl::finish_unlock() {
+  assert(m_lock.is_locked());
+  assert(m_safe && m_consistent);
+
+  Contexts contexts;
+  contexts.swap(m_contexts);
+
+  m_lock.Unlock();
+  for (Contexts::iterator it = contexts.begin();
+       it != contexts.end(); ++it) {
+    (*it)->complete(m_return_value);
+  }
+}
+
+std::ostream &operator<<(std::ostream &os, const FutureImpl &future) {
+  os << "Future[tag_tid=" << future.m_tag_tid << ", "
+     << "entry_tid=" << future.m_entry_tid << ", "
+     << "commit_tid=" << future.m_commit_tid << "]";
+  return os;
+}
+
+void intrusive_ptr_add_ref(FutureImpl::FlushHandler *p) {
+  p->get();
+}
+
+void intrusive_ptr_release(FutureImpl::FlushHandler *p) {
+  p->put();
+}
+
+} // namespace journal