src/ipc/mem/Page.h

   1 #ifndef SQUID_IPC_MEM_PAGE_H
   2 #define SQUID_IPC_MEM_PAGE_H
   3
   4 #include <iosfwd>
   5
   6 namespace Ipc
   7 {
   8
   9 namespace Mem
  10 {
  11
  12 /// Shared memory page identifier, address, or handler
  13 class PageId
  14 {
  15 public:
  16     PageId(): pool(0), number(0), purpose(maxPurpose) {}
  17
  18     /// true if and only if both critical components have been initialized
  19     bool set() const { return pool && number; }
  20
  21     // safer than bool which would enable silent casts to int
  22     typedef const uint32_t PageId::*SaferBool;
  23     operator SaferBool() const { return set() ? &PageId::number : NULL; }
  24
  25     uint32_t pool; ///< page pool ID within Squid
  26     // uint32_t segment; ///< memory segment ID within the pool; unused for now
  27     uint32_t number; ///< page number within the segment
  28
  29     enum Purpose { cachePage, ioPage, maxPurpose };
  30     Purpose purpose; ///< page purpose
  31 };
  32
  33 /// writes page address (e.g., "sh_page5.3"), for debugging
  34 std::ostream &operator <<(std::ostream &os, const PageId &page);
  35
  36 } // namespace Mem
  37
  38 } // namespace Ipc
  39
  40 #endif // SQUID_IPC_MEM_PAGE_H