Memory Manager

Memory Manager, which controls memory allocations, deallocations, and sharing. More...

Detailed Description

Memory Manager, which controls memory allocations, deallocations, and sharing.

This package contains classes that control memory allocations, deallocations, and sharing.

Collaboration diagram for Memory Manager:

Modules
	Memory Hierarchy
	NUMA-Aware Memory Hierarchy in libfoedus-core.

Files
file	fwd.hpp
	Forward declarations of classes in memory package.
file	memory_id.hpp
	Definitions of IDs in this package and a few related constant values.

Classes
class	foedus::memory::AlignedMemory
	Represents one memory block aligned to actual OS/hardware pages. More...
struct	foedus::memory::AlignedMemorySlice
	A slice of foedus::memory::AlignedMemory. More...
struct	foedus::memory::ScopedNumaPreferred
	Automatically sets and resets numa_set_preferred(). More...
struct	foedus::memory::MemoryOptions
	Set of options for memory manager. More...
struct	foedus::memory::AutoVolatilePageReleaseScope
	Automatically invokes a page offset acquired for volatile page. More...
class	foedus::memory::PagePoolOffsetChunk
	To reduce the overhead of grabbing/releasing pages from pool, we pack this many pointers for each grab/release. More...
struct	foedus::memory::PagePoolOffsetAndEpochChunk::OffsetAndEpoch
class	foedus::memory::PagePoolOffsetAndEpochChunk
	Used to store an epoch value with each entry in PagePoolOffsetChunk. More...
struct	foedus::memory::PagePool::Stat
class	foedus::memory::PagePool
	Page pool for volatile read/write store (VolatilePage) and the read-only bufferpool (SnapshotPage). More...
class	foedus::memory::PageReleaseBatch
	A helper class to return a bunch of pages to individual nodes. More...
class	foedus::memory::RoundRobinPageGrabBatch
	A helper class to grab a bunch of pages from multiple nodes in round-robin fashion per chunk. More...
class	foedus::memory::DivvyupPageGrabBatch
	A helper class to grab a bunch of pages from multiple nodes in arbitrary fashion. More...
class	foedus::memory::PagePoolPimpl
	Pimpl object of PagePool. More...
struct	foedus::memory::LocalPageResolver
	Resolves an offset in local (same NUMA node) page pool to a pointer and vice versa. More...
struct	foedus::memory::GlobalVolatilePageResolver
	Resolves an offset in a volatile page pool to an actual pointer and vice versa. More...
class	foedus::memory::SharedMemory
	Represents memory shared between processes. More...

Typedefs
typedef uint32_t	foedus::memory::PagePoolOffset
	Offset in PagePool that compactly represents the page address (unlike 8 bytes pointer). More...

Variables
const uint64_t	foedus::memory::kHugepageSize = 1 << 21
	So far 2MB is the only page size available via Transparent Huge Page (THP). More...

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Class Documentation

struct foedus::memory::PagePoolOffsetAndEpochChunk::OffsetAndEpoch

Definition at line 123 of file page_pool.hpp.

Class Members
PagePoolOffset	offset_
EpochInteger	safe_epoch_

struct foedus::memory::PagePool::Stat

Definition at line 175 of file page_pool.hpp.

Class Members
uint64_t	allocated_pages_
uint64_t	total_pages_

Typedef Documentation

typedef uint32_t foedus::memory::PagePoolOffset

Offset in PagePool that compactly represents the page address (unlike 8 bytes pointer).

Offset 0 means nullptr. Page-0 never appears as a valid page. In our engine, all page pools are per-NUMA node. Thus, each NUMA node has its own page pool. The maximum size of a single page pool is 2^32 * page size (4kb page: 16TB). This should be sufficient for one NUMA node.

Definition at line 44 of file memory_id.hpp.

Variable Documentation

const uint64_t foedus::memory::kHugepageSize = 1 << 21

So far 2MB is the only page size available via Transparent Huge Page (THP).

Definition at line 50 of file memory_id.hpp.

Referenced by foedus::memory::NumaNodeMemory::allocate_huge_numa_memory(), foedus::memory::NumaNodeMemory::allocate_numa_memory_general(), foedus::snapshot::LogMapper::initialize_once(), and foedus::snapshot::LogReducer::initialize_once().