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 #include "ipc/mem/Page.h"
  10
  11 namespace Ipc
  12 {
  13
  14 namespace Mem
  15 {
  16
  17 /* Single page manipulation */
  18
  19 /// sets page ID and returns true unless no free pages are found
  20 bool GetPage(const PageId::Purpose purpose, PageId &page);
  21
  22 /// makes identified page available as a free page to future GetPage() callers
  23 void PutPage(PageId &page);
  24
  25 /// converts page handler into a temporary writeable shared memory pointer
  26 char *PagePointer(const PageId &page);
  27
  28
  29 /* Limits and statistics */
  30
  31 /// the total number of shared memory pages that can be in use at any time
  32 size_t PageLimit();
  33
  34 /// the total number of shared memory pages that can be in use at any
  35 /// time for given purpose
  36 size_t PageLimit(const int purpose);
  37
  38 /// approximate total number of shared memory pages used now
  39 size_t PageLevel();
  40
  41 /// approximate total number of shared memory pages used now for given purpose
  42 size_t PageLevel(const int purpose);
  43
  44 /// approximate total number of shared memory pages we can allocate now
  45 inline size_t PagesAvailable() { return PageLimit() - PageLevel(); }
  46
  47 /// approximate total number of shared memory pages we can allocate
  48 /// now for given purpose
  49 inline size_t PagesAvailable(const int purpose) { return PageLimit(purpose) - PageLevel(purpose); }
  50
  51 /// returns page size in bytes; all pages are assumed to be the same size
  52 size_t PageSize();
  53
  54 } // namespace Mem
  55
  56 } // namespace Ipc
  57
  58 #endif // SQUID_IPC_MEM_PAGES_H