Memory Management (Memory Pool Allocator)

Collaboration diagram for Memory Management (Memory Pool Allocator):

Classes
class	MemPoolIterator
class	mgb_t
class	MemPoolMeter
class	MemPools
class	MemAllocator
class	MemImplementingAllocator
class	MemPoolStats
struct	_MemPoolGlobalStats
class	MemPoolChunked
class	MemChunk
class	MemPoolMalloc

Macros
#define	toMB(size)   ( ((double) size) / ((double)(1024*1024)) )
#define	toKB(size)   ( (size + 1024 - 1) / 1024 )
#define	MEM_PAGE_SIZE   4096
#define	MEM_MIN_FREE   32
#define	MEM_MAX_FREE   65535 /* unsigned short is max number of items per chunk */
#define	memPoolCreate   MemPools::GetInstance().create

Typedefs
typedef struct _MemPoolGlobalStats	MemPoolGlobalStats

Functions
MemPoolIterator *	memPoolIterate (void)
MemImplementingAllocator *	memPoolIterateNext (MemPoolIterator *iter)
void	memPoolIterateDone (MemPoolIterator **iter)
int	memPoolGetGlobalStats (MemPoolGlobalStats *stats)
int	memPoolsTotalAllocated (void)

Detailed Description

MemPools are a pooled memory allocator running on top of malloc(). It's purpose is to reduce memory fragmentation and provide detailed statistics on memory consumption.

Preferably all memory allocations in Squid should be done using MemPools or one of the types built on top of it (i.e. cbdata).

Note

Usually it is better to use cbdata types as these gives you additional safeguards in references and typechecking. However, for high usage pools where the cbdata functionality of cbdata is not required directly using a MemPool might be the way to go.

Macro Definition Documentation

MEM_MAX_FREE

#define MEM_MAX_FREE   65535 /* unsigned short is max number of items per chunk */

Definition at line 59 of file Pool.h.

Referenced by MemPoolChunked::setChunkSize().

MEM_MIN_FREE

#define MEM_MIN_FREE   32

Definition at line 57 of file Pool.h.

Referenced by MemPoolChunked::setChunkSize().

MEM_PAGE_SIZE

#define MEM_PAGE_SIZE   4096

Definition at line 55 of file Pool.h.

Referenced by MemPoolChunked::setChunkSize().

memPoolCreate

#define memPoolCreate   MemPools::GetInstance().create

Creates a named MemPool of elements with the given size

Definition at line 325 of file Pool.h.

Referenced by authenticateDigestNonceSetup(), cbdataInternalInitType(), createRemovalPolicy_lru(), GetStrPool(), memDataInit(), StoreEntry::operator new(), squidaio_init(), and testMem::testMemPool().

toKB

#define toKB

(

size

)

( (size + 1024 - 1) / 1024 )

Definition at line 52 of file Pool.h.

Referenced by Mem::PoolReport().

toMB

#define toMB

(

size

)

( ((double) size) / ((double)(1024*1024)) )

Definition at line 50 of file Pool.h.

Referenced by memConfigure(), and Mem::Report().

Typedef Documentation

MemPoolGlobalStats

typedef struct _MemPoolGlobalStats MemPoolGlobalStats

Todo:

Kill this typedef for C++

Definition at line 66 of file Pool.h.

Function Documentation

memPoolGetGlobalStats()

int memPoolGetGlobalStats

(

MemPoolGlobalStats *

stats

)

Todo:

Stats API - not sured how to refactor yet

Fills a MemPoolGlobalStats with statistical data about overall usage for all pools.

Parameters

stats

Object to be filled with statistical data.

Returns

Number of pools that have at least one object in use. Ie. number of dirty pools.

Definition at line 250 of file Pool.cc.

References MemPoolStats::chunks_alloc, MemPoolStats::chunks_free, MemPoolStats::chunks_inuse, MemPoolStats::chunks_partial, MemPools::flushMeters(), MemPools::GetInstance(), MemAllocator::getStats(), MemPoolStats::items_alloc, MemPoolStats::items_idle, MemPoolStats::items_inuse, MemPools::mem_idle_limit, _MemPoolGlobalStats::mem_idle_limit, memPoolIterate(), memPoolIterateDone(), memPoolIterateNext(), MemPoolStats::overhead, Pool_id_counter, MemPools::poolCount, TheMeter, _MemPoolGlobalStats::TheMeter, _MemPoolGlobalStats::tot_chunks_alloc, _MemPoolGlobalStats::tot_chunks_free, _MemPoolGlobalStats::tot_chunks_inuse, _MemPoolGlobalStats::tot_chunks_partial, _MemPoolGlobalStats::tot_items_alloc, _MemPoolGlobalStats::tot_items_idle, _MemPoolGlobalStats::tot_items_inuse, _MemPoolGlobalStats::tot_overhead, _MemPoolGlobalStats::tot_pools_alloc, _MemPoolGlobalStats::tot_pools_inuse, and _MemPoolGlobalStats::tot_pools_mempid.

Referenced by DumpInfo(), GetInfo(), memClean(), memPoolsTotalAllocated(), and Mem::Report().

memPoolIterate()

MemPoolIterator* memPoolIterate

(

void

)

Initialise iteration through all of the pools.

Returns

Iterator for use by memPoolIterateNext() and memPoolIterateDone()

Definition at line 40 of file Pool.cc.

References MemPools::GetInstance(), Iterator, MemPoolIterator::pool, and MemPools::pools.

Referenced by MemPools::clean(), MemPools::flushMeters(), memPoolGetGlobalStats(), and Mem::Report().

memPoolIterateDone()

void memPoolIterateDone

(

MemPoolIterator **

iter

)

Should be called after finished with iterating through all pools.

Definition at line 47 of file Pool.cc.

References assert, NULL, and MemPoolIterator::pool.

Referenced by MemPools::clean(), MemPools::flushMeters(), memPoolGetGlobalStats(), and Mem::Report().

memPoolIterateNext()

MemImplementingAllocator* memPoolIterateNext

(

MemPoolIterator *

iter

)

Get next pool pointer, until getting NULL pointer.

Definition at line 55 of file Pool.cc.

References assert, MemImplementingAllocator::next, NULL, and MemPoolIterator::pool.

Referenced by MemPools::clean(), MemPools::flushMeters(), memPoolGetGlobalStats(), and Mem::Report().

memPoolsTotalAllocated()

int memPoolsTotalAllocated

(

void

)

Definition at line 299 of file Pool.cc.

References MemPoolMeter::alloc, Mem::Meter::currentLevel(), memPoolGetGlobalStats(), Ping::stats, and _MemPoolGlobalStats::TheMeter.

Referenced by statMemoryAccounted().