src/ipc/mem/Pages.h

   1 /*
   2  * $Id$
   3  *
   4  */
   5
   6 #ifndef SQUID_IPC_MEM_PAGES_H
   7 #define SQUID_IPC_MEM_PAGES_H
   8
   9 namespace Ipc {
  10
  11 namespace Mem {
  12
  13 class PageId;
  14
  15 /* Single page manipulation */
  16
  17 /// sets page ID and returns true unless no free pages are found
  18 bool GetPage(PageId &page);
  19
  20 /// makes identified page available as a free page to future GetPage() callers
  21 void PutPage(PageId &page);
  22
  23 /// converts page handler into a temporary writeable shared memory pointer
  24 void *PagePointer(const PageId &page);
  25
  26
  27 /* Limits and statistics */
  28
  29 /// the total number of shared memory bytes that can be in use at any time
  30 size_t Limit();
  31
  32 /// approximate total number of shared memory bytes used now
  33 size_t Level();
  34
  35 /// approximate total number of shared memory bytes we can allocate now
  36 inline size_t Available() { return Limit() - Level(); }
  37
  38 /// returns page size in bytes; all pages are assumed to be the same size
  39 size_t PageSize();
  40
  41 } // namespace Mem
  42
  43 } // namespace Ipc
  44
  45 #endif // SQUID_IPC_MEM_PAGES_H