src/ipc/mem/Pages.h

   1 /*
   2  */
   3
   4 #ifndef SQUID_IPC_MEM_PAGES_H
   5 #define SQUID_IPC_MEM_PAGES_H
   6
   7 #include "ipc/mem/Page.h"
   8
   9 namespace Ipc
  10 {
  11
  12 namespace Mem
  13 {
  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 /* Limits and statistics */
  27
  28 /// the total number of shared memory pages that can be in use at any time
  29 size_t PageLimit();
  30
  31 /// the total number of shared memory pages that can be in use at any
  32 /// time for given purpose
  33 size_t PageLimit(const int purpose);
  34
  35 /// approximate total number of shared memory pages used now
  36 size_t PageLevel();
  37
  38 /// approximate total number of shared memory pages used now for given purpose
  39 size_t PageLevel(const int purpose);
  40
  41 /// approximate total number of shared memory pages we can allocate now
  42 inline size_t PagesAvailable() { return PageLimit() - PageLevel(); }
  43
  44 /// approximate total number of shared memory pages we can allocate
  45 /// now for given purpose
  46 inline size_t PagesAvailable(const int purpose) { return PageLimit(purpose) - PageLevel(purpose); }
  47
  48 /// returns page size in bytes; all pages are assumed to be the same size
  49 size_t PageSize();
  50
  51 /// claim the need for a number of pages for a given purpose
  52 void NotePageNeed(const int purpose, const int count);
  53
  54 } // namespace Mem
  55
  56 } // namespace Ipc
  57
  58 #endif // SQUID_IPC_MEM_PAGES_H