git.sesse.net Git - casparcg/blob - common/page_locked_allocator.cpp

   1 #include "stdafx.h"
   2
   3 #include "os/windows/windows.h"
   4
   5 #include <unordered_map>
   6 #include <tbb/mutex.h>
   7 #include <tbb/atomic.h>
   8
   9 namespace caspar { namespace detail {
  10
  11 tbb::mutex                                                      g_mutex;
  12 std::unordered_map<void*, size_t>       g_map;
  13 size_t                                                          g_free;
  14
  15 void allocate_store(size_t size)
  16 {
  17         SIZE_T workingSetMinSize = 0, workingSetMaxSize = 0;
  18         if(::GetProcessWorkingSetSize(::GetCurrentProcess(), &workingSetMinSize, &workingSetMaxSize))
  19         {
  20                 workingSetMinSize += size;
  21                 workingSetMaxSize += size;
  22
  23                 if(!::SetProcessWorkingSetSize(::GetCurrentProcess(), workingSetMinSize, workingSetMaxSize))
  24                         throw std::bad_alloc();
  25
  26                 g_free += size;
  27         }
  28 }
  29
  30 void* alloc_page_locked(size_t size)
  31 {
  32         tbb::mutex::scoped_lock lock(g_mutex);
  33
  34         if(g_free < size)
  35                 allocate_store(size);
  36
  37         auto p = ::VirtualAlloc(NULL, size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
  38         if(!p)
  39                 throw std::bad_alloc();
  40
  41         if(::VirtualLock(p, size) == 0)
  42         {
  43                 ::VirtualFree(p, 0, MEM_RELEASE);
  44                 throw std::bad_alloc();
  45         }
  46
  47         g_free   -= size;
  48         g_map[p]        = size;
  49         return p;
  50
  51 }
  52
  53 void free_page_locked(void* p)
  54 {
  55         tbb::mutex::scoped_lock lock(g_mutex);
  56
  57         if(g_map.find(p) == g_map.end())
  58                 return;
  59
  60         ::VirtualFree(p, 0, MEM_RELEASE);
  61
  62         g_free += g_map[p];
  63         g_map.erase(p);
  64 }
  65
  66 }}