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 namespace Mem {
  14
  15 /* Single page manipulation */
  16
  17 /// sets page ID and returns true unless no free pages are found
  18 bool GetPage(const PageId::Purpose purpose, 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 char *PagePointer(const PageId &page);
  25
  26
  27 /* Limits and statistics */
  28
  29 /// the total number of shared memory pages that can be in use at any time
  30 size_t PageLimit();
  31
  32 /// the total number of shared memory pages that can be in use at any
  33 /// time for given purpose
  34 size_t PageLimit(const int purpose);
  35
  36 /// approximate total number of shared memory pages used now
  37 size_t PageLevel();
  38
  39 /// approximate total number of shared memory pages used now for given purpose
  40 size_t PageLevel(const int purpose);
  41
  42 /// approximate total number of shared memory pages we can allocate now
  43 inline size_t PagesAvailable() { return PageLimit() - PageLevel(); }
  44
  45 /// approximate total number of shared memory pages we can allocate
  46 /// now for given purpose
  47 inline size_t PagesAvailable(const int purpose) { return PageLimit(purpose) - PageLevel(purpose); }
  48
  49 /// returns page size in bytes; all pages are assumed to be the same size
  50 size_t PageSize();
  51
  52 } // namespace Mem
  53
  54 } // namespace Ipc
  55
  56 #endif // SQUID_IPC_MEM_PAGES_H