hphp/runtime/vm/workload-stats.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 #ifndef incl_HPHP_WORKLOAD_STATS_H_
  18 #define incl_HPHP_WORKLOAD_STATS_H_
  19
  20 #include <cstdint>
  21
  22 namespace HPHP {
  23
  24 // WorkloadStats is used to track per request timing for different states
  25 // of the VM.  At the entrypoint to a change of vm state a WorkloadStats object
  26 // should be made to guard the state change with appropriate timers and
  27 // counters.
  28 //
  29 // The states tracked are:
  30 //  - In a request (this is a superset of the interpreter state)
  31 //  - In the interpreter through Dispatch, or DispatchBB (interpOne disregarded)
  32 //  - In the JIT (currently tracks time inside the translate routine)
  33 //
  34 // Note the time in the TC is not tracked.  This is roughly:
  35 //   Time in request - Time in interp
  36 //
  37 // This gives us the relative interp time formula of:
  38 //   Relative interp time = Time in interp / Time in request
  39 struct WorkloadStats final {
  40   enum State {
  41     InRequest,
  42     // -> InInterp   Okay (entering Dispatch loop)
  43     // -> InTrans    Okay (entering translate)
  44     InInterp,
  45     // -> InRequest  Okay (leaving the dispatch loop)
  46     // -> InTrans    Okay (entering translate)
  47     InTrans,
  48     // -> InRequest  Okay (leaving translate)
  49     // -> InInterp   Okay (leaving translate)
  50   };
  51
  52   explicit WorkloadStats(State guardedState);
  53   ~WorkloadStats();
  54
  55   WorkloadStats (const WorkloadStats&) = delete;
  56   WorkloadStats& operator=(const WorkloadStats&) = delete;
  57
  58   static int64_t GetAndResetAvgRelativeInterp();
  59 };
  60
  61 }
  62
  63 #endif