vm/sampling_profiler.cpp

   1 #include "master.hpp"
   2
   3 namespace factor
   4 {
   5
   6 profiling_sample::profiling_sample(factor_vm *vm,
   7         cell sample_count,
   8         cell gc_sample_count,
   9         context *ctx)
  10         :
  11         sample_count(sample_count),
  12         gc_sample_count(gc_sample_count),
  13         ctx(ctx)
  14 {
  15         vm->record_callstack_sample(&callstack_begin, &callstack_end);
  16 }
  17
  18 void factor_vm::record_sample()
  19 {
  20         cell recorded_sample_count;
  21         cell recorded_gc_sample_count;
  22
  23         recorded_sample_count = safepoint_sample_count;
  24         recorded_gc_sample_count = safepoint_gc_sample_count;
  25         if (recorded_sample_count == 0 && recorded_gc_sample_count == 0)
  26                 return;
  27
  28         /* Another sample signal could be raised while we record these counts */
  29         FACTOR_ATOMIC_SUB(&safepoint_sample_count, recorded_sample_count);
  30         FACTOR_ATOMIC_SUB(&safepoint_gc_sample_count, recorded_gc_sample_count);
  31
  32         samples.push_back(profiling_sample(
  33                 this,
  34                 recorded_sample_count,
  35                 recorded_gc_sample_count,
  36                 ctx
  37         ));
  38 }
  39
  40 void factor_vm::record_callstack_sample(cell *begin, cell *end)
  41 {
  42         *begin = sample_callstacks.size();
  43         stack_frame *frame = ctx->bottom_frame();
  44
  45         while (frame >= ctx->callstack_top) {
  46                 sample_callstacks.push_back(frame_code(frame));
  47                 frame = frame_successor(frame);
  48         }
  49
  50         *end = sample_callstacks.size();
  51 }
  52
  53 void factor_vm::set_sampling_profiler(bool sampling_p)
  54 {
  55         if (sampling_p == sampling_profiler_p)
  56                 return;
  57
  58         if (sampling_p)
  59                 start_sampling_profiler();
  60         else
  61                 end_sampling_profiler();
  62 }
  63
  64 void factor_vm::start_sampling_profiler()
  65 {
  66         safepoint_sample_count = 0;
  67         safepoint_gc_sample_count = 0;
  68         samples.clear();
  69         samples.reserve(10*FACTOR_PROFILE_SAMPLES_PER_SECOND);
  70         sample_callstacks.reserve(100*FACTOR_PROFILE_SAMPLES_PER_SECOND);
  71         sampling_profiler_p = true;
  72         start_sampling_profiler_timer();
  73 }
  74
  75 void factor_vm::end_sampling_profiler()
  76 {
  77         end_sampling_profiler_timer();
  78         record_sample();
  79         sampling_profiler_p = false;
  80 }
  81
  82 void factor_vm::primitive_sampling_profiler()
  83 {
  84         set_sampling_profiler(to_boolean(ctx->pop()));
  85 }
  86
  87
  88 }