foedus::storage::sequential::SequentialStorageControlBlock Struct Reference

Shared data of this storage type. More...

Detailed Description

Shared data of this storage type.

Definition at line 49 of file sequential_storage_pimpl.hpp.

#include <sequential_storage_pimpl.hpp>

Collaboration diagram for foedus::storage::sequential::SequentialStorageControlBlock:

Public Member Functions
	SequentialStorageControlBlock ()=delete
	~SequentialStorageControlBlock ()=delete
bool	exists () const
ErrorCode	optimistic_read_truncate_epoch (thread::Thread *context, Epoch *out) const

Public Attributes
soc::SharedMutex	status_mutex_
StorageStatus	status_
	Status of the storage. More...
DualPagePointer	root_page_pointer_
	Points to the root page (or something equivalent). More...
SequentialMetadata	meta_
	metadata of this storage. More...
xct::RwLockableXctId	cur_truncate_epoch_tid_
	Protects accesses to cur_truncate_epoch_. More...
std::atomic< Epoch::EpochInteger >	cur_truncate_epoch_
	The min epoch value (truncate-epoch) for all valid records in this storage. More...
VolatilePagePointer	head_pointer_pages_ [kPointerPageCount]
	Points to pages that store thread-private head pages to store thread-private volatile pages. More...
VolatilePagePointer	tail_pointer_pages_ [kPointerPageCount]
	Same above, but for tail pointers. More...

Constructor & Destructor Documentation

foedus::storage::sequential::SequentialStorageControlBlock::SequentialStorageControlBlock ( )

delete

foedus::storage::sequential::SequentialStorageControlBlock::~SequentialStorageControlBlock ( )

delete

Member Function Documentation

bool foedus::storage::sequential::SequentialStorageControlBlock::exists ( ) const

inline

Definition at line 54 of file sequential_storage_pimpl.hpp.

References foedus::storage::kExists, foedus::storage::kMarkedForDeath, and status_.

{ return status_ == kExists || status_ == kMarkedForDeath; }

ErrorCode foedus::storage::sequential::SequentialStorageControlBlock::optimistic_read_truncate_epoch	(	thread::Thread *	context,
		Epoch *	out
	)		const

Definition at line 213 of file sequential_storage_pimpl.cpp.

References foedus::xct::Xct::add_to_lock_free_read_set(), CHECK_ERROR_CODE, cur_truncate_epoch_, cur_truncate_epoch_tid_, foedus::thread::Thread::get_current_xct(), foedus::storage::Metadata::id_, foedus::xct::Xct::is_active(), foedus::xct::XctId::is_being_written(), foedus::kErrorCodeOk, foedus::kErrorCodeXctNoXct, foedus::assorted::memory_fence_acquire(), meta_, and UNLIKELY.

                    {
  xct::Xct& cur_xct = context->get_current_xct();
  if (!cur_xct.is_active()) {
    return kErrorCodeXctNoXct;
  }

  auto* address = &cur_truncate_epoch_tid_;
  xct::XctId observed = address->xct_id_;
  while (UNLIKELY(observed.is_being_written())) {
    assorted::memory_fence_acquire();
    observed = address->xct_id_;
  }

  *out = Epoch(cur_truncate_epoch_.load());  // atomic!
  CHECK_ERROR_CODE(cur_xct.add_to_lock_free_read_set(
    meta_.id_,
    observed,
    const_cast< xct::RwLockableXctId* >(address)));  // why it doesn't receive const? I forgot..
  return kErrorCodeOk;
}

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Member Data Documentation

std::atomic< Epoch::EpochInteger > foedus::storage::sequential::SequentialStorageControlBlock::cur_truncate_epoch_

The min epoch value (truncate-epoch) for all valid records in this storage.

When a physical record or a page has an epoch value less than a truncate-epoch, they are logically non-existent. Truncate-epoch is always valid, starting from the system's lowest epoch.

Definition at line 77 of file sequential_storage_pimpl.hpp.

Referenced by optimistic_read_truncate_epoch().

xct::RwLockableXctId foedus::storage::sequential::SequentialStorageControlBlock::cur_truncate_epoch_tid_

Protects accesses to cur_truncate_epoch_.

• Append-operations don't need to check it.
• Scan-operations take this as a read-set.
• Truncate-operation locks it and update cur_truncate_epoch_.

Definition at line 74 of file sequential_storage_pimpl.hpp.

Referenced by optimistic_read_truncate_epoch().

VolatilePagePointer foedus::storage::sequential::SequentialStorageControlBlock::head_pointer_pages_[kPointerPageCount]

Points to pages that store thread-private head pages to store thread-private volatile pages.

Each page can contain 2^10 pointers (as the node is implicit, PagePoolOffset suffices) and we can have at most 2^16 cores. Thus we have 2^6 pointers here. This means we can waste 64*2=128 volatile pages (=512kb) per one sequential storage.. shouldn't be a big issue.

Definition at line 86 of file sequential_storage_pimpl.hpp.

SequentialMetadata foedus::storage::sequential::SequentialStorageControlBlock::meta_

metadata of this storage.

Definition at line 63 of file sequential_storage_pimpl.hpp.

Referenced by optimistic_read_truncate_epoch().

DualPagePointer foedus::storage::sequential::SequentialStorageControlBlock::root_page_pointer_

Points to the root page (or something equivalent).

Definition at line 61 of file sequential_storage_pimpl.hpp.

StorageStatus foedus::storage::sequential::SequentialStorageControlBlock::status_

Status of the storage.

Definition at line 59 of file sequential_storage_pimpl.hpp.

Referenced by exists().

soc::SharedMutex foedus::storage::sequential::SequentialStorageControlBlock::status_mutex_

Definition at line 57 of file sequential_storage_pimpl.hpp.

VolatilePagePointer foedus::storage::sequential::SequentialStorageControlBlock::tail_pointer_pages_[kPointerPageCount]

Same above, but for tail pointers.

Definition at line 88 of file sequential_storage_pimpl.hpp.

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The documentation for this struct was generated from the following files:

• /home/shino/foedus_code/foedus-core/include/foedus/storage/sequential/sequential_storage_pimpl.hpp
• /home/shino/foedus_code/foedus-core/src/foedus/storage/sequential/sequential_storage_pimpl.cpp