class SectionMemoryManager::MemoryMapper

Declaration

class SectionMemoryManager::MemoryMapper { /* full declaration omitted */ };

Description

Implementations of this interface are used by SectionMemoryManager to request pages from the operating system.

Declared at: llvm/include/llvm/ExecutionEngine/SectionMemoryManager.h:51

Method Overview

  • public virtual sys::MemoryBlock allocateMappedMemory(llvm::SectionMemoryManager::AllocationPurpose Purpose, size_t NumBytes, const sys::MemoryBlock *const NearBlock, unsigned int Flags, std::error_code & EC)
  • public virtual std::error_code protectMappedMemory(const sys::MemoryBlock & Block, unsigned int Flags)
  • public virtual std::error_code releaseMappedMemory(sys::MemoryBlock & M)
  • public virtual ~MemoryMapper()

Methods

virtual sys::MemoryBlock allocateMappedMemory(
    llvm::SectionMemoryManager::AllocationPurpose
        Purpose,
    size_t NumBytes,
    const sys::MemoryBlock* const NearBlock,
    unsigned int Flags,
    std::error_code& EC)

Description

This method attempts to allocate \p NumBytes bytes of virtual memory for\p Purpose. \p NearBlock may point to an existing allocation, in which case an attempt is made to allocate more memory near the existing block. The actual allocated address is not guaranteed to be near the requested address. \p Flags is used to set the initial protection flags for the block of the memory. \p EC [out] returns an object describing any error that occurs. This method may allocate more than the number of bytes requested. The actual number of bytes allocated is indicated in the returned MemoryBlock. The start of the allocated block must be aligned with the system allocation granularity (64K on Windows, page size on Linux). If the address following \p NearBlock is not so aligned, it will be rounded up to the next allocation granularity boundary. \ra non-null MemoryBlock if the function was successful, otherwise a null MemoryBlock with \p EC describing the error.

Declared at: llvm/include/llvm/ExecutionEngine/SectionMemoryManager.h:73

Parameters

llvm::SectionMemoryManager::AllocationPurpose Purpose
size_t NumBytes
const sys::MemoryBlock* const NearBlock
unsigned int Flags
std::error_code& EC

virtual std::error_code protectMappedMemory(
    const sys::MemoryBlock& Block,
    unsigned int Flags)

Description

This method sets the protection flags for a block of memory to the state specified by \p Flags. The behavior is not specified if the memory was not allocated using the allocateMappedMemory method.\p Block describes the memory block to be protected.\p Flags specifies the new protection state to be assigned to the block. If \p Flags is MF_WRITE, the actual behavior varies with the operating system (i.e. MF_READ | MF_WRITE on Windows) and the target architecture (i.e. MF_WRITE -> MF_READ | MF_WRITE on i386). \rerror_success if the function was successful, or an error_code describing the failure if an error occurred.

Declared at: llvm/include/llvm/ExecutionEngine/SectionMemoryManager.h:89

Parameters

const sys::MemoryBlock& Block
unsigned int Flags

virtual std::error_code releaseMappedMemory(
    sys::MemoryBlock& M)

Description

This method releases a block of memory that was allocated with the allocateMappedMemory method. It should not be used to release any memory block allocated any other way.\p Block describes the memory to be released. \rerror_success if the function was successful, or an error_code describing the failure if an error occurred.

Declared at: llvm/include/llvm/ExecutionEngine/SectionMemoryManager.h:99

Parameters

sys::MemoryBlock& M

virtual ~MemoryMapper()

Declared at: llvm/include/llvm/ExecutionEngine/SectionMemoryManager.h:101