KDBG/TraceDataHeader.hpp

   1 //
   2 //  TraceDataHeader.hpp
   3 //  KDBG
   4 //
   5 //  Created by James McIlree on 10/25/12.
   6 //  Copyright (c) 2014 Apple. All rights reserved.
   7 //
   8
   9 //
  10 // We have to specialize this, as the K64 min alignment is 4 bytes longer,
  11 // to maintain 8 byte alignment for the uint64_t _TOD_secs.
  12 //
  13
  14 template <typename KERNEL_SIZE> class TraceDataHeaderFields {};
  15
  16 template <>
  17 class TraceDataHeaderFields<Kernel32> {
  18     public:
  19         uint32_t        version;
  20         uint32_t        thread_count;
  21         uint32_t        TOD_secs_top_half;
  22         uint32_t        TOD_secs_bottom_half;
  23         uint32_t        TOD_usecs;
  24
  25         // NOTE! The compiler has shown a tendency to place this on non 8 byte
  26         // aligned addresses when stack allocating. We need to construct the
  27         // uint64_t values by logical-or and shifting, treating as a pointer
  28         // will fail!
  29
  30         TraceDataHeaderFields(uint32_t v, uint32_t tc, uint64_t s, uint32_t us) :
  31                 version(v),
  32                 thread_count(tc),
  33                 TOD_usecs(us)
  34         {
  35                 TOD_secs_top_half = (uint32_t)(s >> 32);
  36                 TOD_secs_bottom_half = (uint32_t)(s & 0xFFFFFFFF);
  37         }
  38
  39         uint64_t TOD_secs() {
  40                 return ((uint64_t)TOD_secs_top_half << 32) | (uint64_t)TOD_secs_bottom_half;
  41         }
  42 };
  43
  44 template <>
  45 class TraceDataHeaderFields<Kernel64> {
  46     public:
  47         uint32_t        version;
  48         uint32_t        thread_count;
  49         uint64_t        _TOD_secs;
  50         uint32_t        TOD_usecs;
  51         uint32_t        _force_alignment; // Need to force 8 byte alignment in 32 bit code
  52
  53         TraceDataHeaderFields(uint32_t v, uint32_t tc, uint64_t s, uint32_t us) :
  54                 version(v),
  55                 thread_count(tc),
  56                 _TOD_secs(s),
  57                 TOD_usecs(us),
  58                 _force_alignment(0)
  59         {
  60         }
  61
  62         uint64_t TOD_secs() {
  63                 return _TOD_secs;
  64         }
  65 };
  66
  67 template <typename KERNEL_SIZE>
  68 class TraceDataHeader {
  69     private:
  70         TraceDataHeaderFields<KERNEL_SIZE>      _fields;
  71
  72     public:
  73         TraceDataHeader() : _fields(0, 0, 0, 0) {}
  74         TraceDataHeader(uint32_t v, uint32_t tc, uint64_t s, uint32_t us) : _fields(v, tc, s, us) {}
  75
  76         uint32_t version() const                        { return _fields.version; }
  77         uint32_t thread_count() const                   { return _fields.thread_count; }
  78         uint64_t TOD_secs() const                       { return _fields.TOD_secs(); }
  79         uint32_t TOD_usecs() const                      { return _fields.TOD_usecs; }
  80 };
  81