PageAllocator Class Reference

#include <v8-platform.h>

Public Types
enum	Permission {   kNoAccess , kRead , kReadWrite , kReadWriteExecute ,   kReadExecute }

Public Member Functions
virtual	~PageAllocator ()=default
virtual size_t	AllocatePageSize ()=0
virtual size_t	CommitPageSize ()=0
virtual void	SetRandomMmapSeed (int64_t seed)=0
virtual void *	GetRandomMmapAddr ()=0
virtual void *	AllocatePages (void *address, size_t length, size_t alignment, Permission permissions)=0
virtual bool	FreePages (void *address, size_t length)=0
virtual bool	ReleasePages (void *address, size_t length, size_t new_length)=0
virtual bool	SetPermissions (void *address, size_t length, Permission permissions)=0
virtual bool	DiscardSystemPages (void *address, size_t size)

Detailed Description

A V8 memory page allocator.

Can be implemented by an embedder to manage large host OS allocations.

Definition at line 206 of file v8-platform.h.

Member Enumeration Documentation

Permission

enum Permission

Memory permissions.

Enumerator
kNoAccess
kRead
kReadWrite
kReadWriteExecute
kReadExecute

Definition at line 237 of file v8-platform.h.

Constructor & Destructor Documentation

~PageAllocator()

virtual ~PageAllocator ( )

virtualdefault

Member Function Documentation

AllocatePages()

virtual void* AllocatePages ( void *  address, size_t  length, size_t  alignment, Permission  permissions  )

pure virtual

Allocates memory in range with the given alignment and permission.

AllocatePageSize()

virtual size_t AllocatePageSize ( )

pure virtual

Gets the page granularity for AllocatePages and FreePages. Addresses and lengths for those calls should be multiples of AllocatePageSize().

CommitPageSize()

virtual size_t CommitPageSize ( )

pure virtual

Gets the page granularity for SetPermissions and ReleasePages. Addresses and lengths for those calls should be multiples of CommitPageSize().

DiscardSystemPages()

virtual bool DiscardSystemPages ( void *  address, size_t  size  )

inlinevirtual

Frees memory in the given [address, address + size) range. address and size should be operating system page-aligned. The next write to this memory area brings the memory transparently back.

Definition at line 274 of file v8-platform.h.

FreePages()

virtual bool FreePages ( void *  address, size_t  length  )

pure virtual

Frees memory in a range that was allocated by a call to AllocatePages.

GetRandomMmapAddr()

virtual void* GetRandomMmapAddr ( )

pure virtual

Returns a randomized address, suitable for memory allocation under ASLR. The address will be aligned to AllocatePageSize.

ReleasePages()

virtual bool ReleasePages ( void *  address, size_t  length, size_t  new_length  )

pure virtual

Releases memory in a range that was allocated by a call to AllocatePages.

SetPermissions()

virtual bool SetPermissions ( void *  address, size_t  length, Permission  permissions  )

pure virtual

Sets permissions on pages in an allocated range.

SetRandomMmapSeed()

virtual void SetRandomMmapSeed ( int64_t  seed )

pure virtual

Sets the random seed so that GetRandomMmapAddr() will generate repeatable sequences of random mmap addresses.

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

• include/v8-platform.h