1 //===- MemoryRegion.h -----------------------------------------------------===// 2 // 3 // The MCLinker Project 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 #ifndef LD_MEMORY_REGION_H 10 #define LD_MEMORY_REGION_H 11 #ifdef ENABLE_UNITTEST 12 #include <gtest.h> 13 #endif 14 15 #include <mcld/Config/Config.h> 16 #include <mcld/ADT/Uncopyable.h> 17 #include <mcld/Support/Allocators.h> 18 #include <mcld/Support/Space.h> 19 20 namespace mcld { 21 22 class MemoryArea; 23 24 /** \class MemoryRegion 25 * \brief MemoryRegion is a range of virtual memory which is mapped onto a 26 * range of files which is opened by MemoryArea. 27 * 28 * MemoryArea maps a file onto virtual memory. Clients can get a range of 29 * mapped memory space by requesting a MemoryRegion from MemoryArea, and 30 * read/write the mapped file through the MemoryRegion. 31 * 32 * When two different MemoryRegion may overlap memory space, race condition 33 * may occurs. Clients must call MemoryRegion::sync() explicit to tell the 34 * MemoryArea when to synchronize the virtual memory space with the mapped 35 * file. 36 */ 37 class MemoryRegion : private Uncopyable 38 { 39 friend class Chunk<MemoryRegion, MCLD_REGION_CHUNK_SIZE>; 40 friend class RegionFactory; 41 friend class MemoryArea; 42 43 public: 44 typedef Space::Address Address; 45 typedef Space::ConstAddress ConstAddress; 46 47 private: 48 MemoryRegion(); 49 50 MemoryRegion(const Address pVMAStart, size_t pSize); 51 52 ~MemoryRegion(); 53 54 void setParent(Space& pSpace) { m_pParent = &pSpace; } 55 56 public: 57 /// Create - To wrap a piece of memory and to create a new region. 58 /// This function wraps a piece of memory and to create a new region. Region 59 /// is just a wraper, it is not responsible for deallocate the given memory. 60 /// 61 /// @param pStart [in] The start address of a piece of memory 62 /// @param pSize [in] The size of the given memory 63 static MemoryRegion* Create(void* pStart, size_t pSize); 64 65 /// Create - To wrap a piece of memory and to create a new region. 66 /// This function wraps a piece of memory and to create a new region. Region 67 /// is just a wraper, it is not responsible for deallocate the given memory. 68 /// 69 /// If a wrapped memory comes from a Space, then we say the space is the 70 /// parent of the region. pSpace is a memory counting container. It remembers 71 /// the number of regions in it. A space which has no region will be removed 72 /// quickly. 73 /// 74 /// The wrapped memory will be deallocated by Space when the space has no 75 /// region used it. 76 /// 77 /// @param pStart [in] The start address of a piece of memory 78 /// @param pSize [in] The size of the given memory 79 /// @param pSpace [in] The parent space. 80 static MemoryRegion* Create(void* pStart, size_t pSize, Space& pSpace); 81 82 /// Destroy - To destroy the region 83 /// If the region has a parent space, it will be also remove from the space. 84 /// 85 /// @param pRegion [in, out] pRegion is set to NULL if the destruction is 86 /// success. 87 static void Destroy(MemoryRegion*& pRegion); 88 89 const Space* parent() const { return m_pParent; } 90 Space* parent() { return m_pParent; } 91 92 bool hasParent() const { return (NULL != m_pParent); } 93 94 ConstAddress start() const { return m_VMAStart; } 95 Address start() { return m_VMAStart; } 96 97 ConstAddress end() const { return m_VMAStart+m_Length; } 98 Address end() { return m_VMAStart+m_Length; } 99 100 size_t size() const { return m_Length; } 101 102 ConstAddress getBuffer(size_t pOffset = 0) const 103 { return m_VMAStart+pOffset; } 104 105 Address getBuffer(size_t pOffset = 0) 106 { return m_VMAStart+pOffset; } 107 108 private: 109 Space* m_pParent; 110 Address m_VMAStart; 111 size_t m_Length; 112 }; 113 114 } // namespace of mcld 115 116 #endif 117 118
