include/jitcs_memmgr.h

   1 //===-- jitcs_memmgr.h - A memory manager for code and data -----*- C++ -*-===//
   2 //
   3 // The manager is an allocator based on Doug Leah's malloc. Memory is allocated
   4 // from the system with execution permission.
   5 // TODO:
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef _JITCS_MEMMGR_H_
  10 #define _JITCS_MEMMGR_H_
  11
  12 #include "jitcs_base.h"
  13 #include <memory>
  14
  15 namespace jitcs {
  16 class MemoryMgrImpl;
  17
  18 class MemoryMgr {
  19 public:
  20   struct Space {
  21     u8* start; size_t size;
  22     static Space Make(u8* s, size_t sz) { Space ps; ps.start = s; ps.size = sz; return ps; }
  23   };
  24   struct CodeAndData {
  25     Space data, code;
  26   };
  27 public:
  28   MemoryMgr();
  29   ~MemoryMgr();
  30
  31 public:
  32   /* todo
  33    * allocate area for function relevant constants (aligned to 16 byte)
  34    * allocate area for code (aligned to cache line size, currently 64 byte)
  35    * allocated areas are stored in a function object, function objects can be forced to free allocated storage
  36    */
  37   CodeAndData allocate(size_t data, size_t code);
  38   void deallocate(CodeAndData);
  39
  40   bool check();
  41   size_t getTotalSpace();
  42   size_t getAllocatedSpace();
  43   size_t getFreeSpace();
  44   size_t getReachableFreeSpace();
  45   bool shrink();
  46
  47 private:
  48   std::unique_ptr<MemoryMgrImpl> _mgr;
  49 };
  50
  51 } // end of namespace jitcs
  52
  53 #endif
  54 // _JITCS_MEMMGR_H_