Pool Class Reference

Classes
struct	PoolEntry

Public Types
typedef llvm::BumpPtrAllocatorImpl< llvm::MallocAllocator, AllocatorSlabSize, SizeThreshold, AllocatorGrowthDelay >	Allocator
typedef const char *	StringPoolValueType
typedef llvm::StringMap< StringPoolValueType, Allocator >	StringPool
typedef llvm::StringMapEntry< StringPoolValueType >	StringPoolEntryType

Public Member Functions
StringPoolValueType	GetMangledCounterpart (const char *ccstr)
const char *	GetConstCString (const char *cstr)
const char *	GetConstCStringWithLength (const char *cstr, size_t cstr_len)
const char *	GetConstCStringWithStringRef (llvm::StringRef string_ref)
const char *	GetConstCStringAndSetMangledCounterPart (llvm::StringRef demangled, const char *mangled_ccstr)
const char *	GetConstTrimmedCStringWithLength (const char *cstr, size_t cstr_len)
ConstString::MemoryStats	GetMemoryStats () const

Static Public Member Functions
static StringPoolEntryType &	GetStringMapEntryFromKeyData (const char *keyData)
static size_t	GetConstCStringLength (const char *ccstr)

Static Public Attributes
static const size_t	AllocatorSlabSize = 4096
	The default BumpPtrAllocatorImpl slab size.
static const size_t	SizeThreshold = AllocatorSlabSize
static const size_t	AllocatorGrowthDelay = 1
	Every Pool has its own allocator which receives an equal share of the ConstString allocations.

Protected Member Functions
PoolEntry &	selectPool (const llvm::StringRef &s)
PoolEntry &	selectPool (uint32_t h)

Protected Attributes
std::array< PoolEntry, 256 >	m_string_pools

Detailed Description

Definition at line 30 of file ConstString.cpp.

Member Typedef Documentation

Allocator

typedef llvm::BumpPtrAllocatorImpl<llvm::MallocAllocator, AllocatorSlabSize, SizeThreshold, AllocatorGrowthDelay> Pool::Allocator

Definition at line 60 of file ConstString.cpp.

StringPool

typedef llvm::StringMap<StringPoolValueType, Allocator> Pool::StringPool

Definition at line 62 of file ConstString.cpp.

StringPoolEntryType

typedef llvm::StringMapEntry<StringPoolValueType> Pool::StringPoolEntryType

Definition at line 63 of file ConstString.cpp.

StringPoolValueType

typedef const char* Pool::StringPoolValueType

Definition at line 61 of file ConstString.cpp.

Member Function Documentation

GetConstCString()

const char * Pool::GetConstCString ( const char *  cstr )

inline

Definition at line 89 of file ConstString.cpp.

References GetConstCStringWithLength().

Referenced by lldb_private::ConstString::SetCString().

GetConstCStringAndSetMangledCounterPart()

const char * Pool::GetConstCStringAndSetMangledCounterPart ( llvm::StringRef  demangled, const char *  mangled_ccstr  )

inline

Definition at line 124 of file ConstString.cpp.

References GetStringMapEntryFromKeyData(), Pool::PoolEntry::m_mutex, Pool::PoolEntry::m_string_map, and selectPool().

Referenced by lldb_private::ConstString::SetStringWithMangledCounterpart().

GetConstCStringLength()

static size_t Pool::GetConstCStringLength ( const char *  ccstr )

inlinestatic

Definition at line 70 of file ConstString.cpp.

References GetStringMapEntryFromKeyData().

Referenced by lldb_private::ConstString::GetLength().

GetConstCStringWithLength()

const char * Pool::GetConstCStringWithLength ( const char *  cstr, size_t  cstr_len  )

inline

Definition at line 95 of file ConstString.cpp.

References GetConstCStringWithStringRef().

Referenced by GetConstCString(), GetConstTrimmedCStringWithLength(), and lldb_private::ConstString::SetCStringWithLength().

GetConstCStringWithStringRef()

const char * Pool::GetConstCStringWithStringRef ( llvm::StringRef  string_ref )

inline

Definition at line 101 of file ConstString.cpp.

References Pool::PoolEntry::m_mutex, Pool::PoolEntry::m_string_map, and selectPool().

Referenced by GetConstCStringWithLength(), and lldb_private::ConstString::SetString().

GetConstTrimmedCStringWithLength()

const char * Pool::GetConstTrimmedCStringWithLength ( const char *  cstr, size_t  cstr_len  )

inline

Definition at line 156 of file ConstString.cpp.

References GetConstCStringWithLength().

Referenced by lldb_private::ConstString::SetTrimmedCStringWithLength().

GetMangledCounterpart()

StringPoolValueType Pool::GetMangledCounterpart ( const char *  ccstr )

inline

Definition at line 80 of file ConstString.cpp.

References GetStringMapEntryFromKeyData(), Pool::PoolEntry::m_mutex, and selectPool().

Referenced by lldb_private::ConstString::GetMangledCounterpart().

GetMemoryStats()

ConstString::MemoryStats Pool::GetMemoryStats ( ) const

inline

Definition at line 165 of file ConstString.cpp.

References lldb_private::ConstString::MemoryStats::bytes_total, lldb_private::ConstString::MemoryStats::bytes_used, and m_string_pools.

Referenced by lldb_private::ConstString::GetMemoryStats().

GetStringMapEntryFromKeyData()

static StringPoolEntryType & Pool::GetStringMapEntryFromKeyData ( const char *  keyData )

inlinestatic

Definition at line 66 of file ConstString.cpp.

Referenced by GetConstCStringAndSetMangledCounterPart(), GetConstCStringLength(), and GetMangledCounterpart().

selectPool() [1/2]

PoolEntry & Pool::selectPool ( const llvm::StringRef &  s )

inlineprotected

Definition at line 184 of file ConstString.cpp.

References selectPool().

Referenced by GetConstCStringAndSetMangledCounterPart(), GetConstCStringWithStringRef(), GetMangledCounterpart(), and selectPool().

selectPool() [2/2]

PoolEntry & Pool::selectPool ( uint32_t  h )

inlineprotected

Definition at line 188 of file ConstString.cpp.

References m_string_pools.

Member Data Documentation

AllocatorGrowthDelay

const size_t Pool::AllocatorGrowthDelay = 1

static

Every Pool has its own allocator which receives an equal share of the ConstString allocations.

This means that when allocating many ConstStrings, every allocator sees only its small share of allocations and assumes LLDB only allocated a small amount of memory so far. In reality LLDB allocated a total memory that is N times as large as what the allocator sees (where N is the number of string pools). This causes that the BumpPtrAllocator continues a long time to allocate memory in small chunks which only makes sense when allocating a small amount of memory (which is true from the perspective of a single allocator). On some systems doing all these small memory allocations causes LLDB to spend a lot of time in malloc, so we need to force all these allocators to behave like one allocator in terms of scaling their memory allocations with increased demand. To do this we set the growth delay for each single allocator to a rate so that our pool of allocators scales their memory allocations similar to a single BumpPtrAllocatorImpl.

Currently we have 256 string pools and the normal growth delay of the BumpPtrAllocatorImpl is 128 (i.e., the memory allocation size increases every 128 full chunks), so by changing the delay to 1 we get a total growth delay in our allocator collection of 256/1 = 256. This is still only half as fast as a normal allocator but we can't go any faster without decreasing the number of string pools.

Definition at line 57 of file ConstString.cpp.

AllocatorSlabSize

const size_t Pool::AllocatorSlabSize = 4096

static

The default BumpPtrAllocatorImpl slab size.

Definition at line 33 of file ConstString.cpp.

m_string_pools

std::array<PoolEntry, 256> Pool::m_string_pools

protected

Definition at line 182 of file ConstString.cpp.

Referenced by GetMemoryStats(), and selectPool().

SizeThreshold

const size_t Pool::SizeThreshold = AllocatorSlabSize

static

Definition at line 34 of file ConstString.cpp.

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The documentation for this class was generated from the following file:

• ConstString.cpp