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 #pragma once
  18
  19 #include <cstdint>
  20
  21 namespace HPHP {
  22
  23 // WorkloadStats is used to track per request timing for different states
  24 // of the VM.  At the entrypoint to a change of vm state a WorkloadStats object
  25 // should be made to guard the state change with appropriate timers and
  26 // counters.
  27 //
  28 // The states tracked are:
  29 //  - In a request (this is a superset of the interpreter state)
  30 //  - In the interpreter through Dispatch, or DispatchBB (interpOne disregarded)
  31 //  - In the JIT (currently tracks time inside the translate routine)
  32 //
  33 // Note the time in the TC is not tracked.  This is roughly:
  34 //   Time in request - Time in interp
  35 //
  36 // This gives us the relative interp time formula of:
  37 //   Relative interp time = Time in interp / Time in request
  38 struct WorkloadStats final {
  39   enum State {
  40     InRequest,
  41     // -> InInterp   Okay (entering Dispatch loop)
  42     // -> InTrans    Okay (entering translate)
  43     InInterp,
  44     // -> InRequest  Okay (leaving the dispatch loop)
  45     // -> InTrans    Okay (entering translate)
  46     InTrans,
  47     // -> InRequest  Okay (leaving translate)
  48     // -> InInterp   Okay (leaving translate)
  49   };
  50
  51   explicit WorkloadStats(State guardedState);
  52   ~WorkloadStats();
  53
  54   WorkloadStats (const WorkloadStats&) = delete;
  55   WorkloadStats& operator=(const WorkloadStats&) = delete;
  56
  57   static int64_t GetAndResetAvgRelativeInterp();
  58   static void EnsureInit();
  59 };
  60
  61 }
  62