Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim: set ts=8 sts=2 et sw=2 tw=80: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : /*
       8             :  * Implementation of the OS-independent methods of the TimeStamp class
       9             :  */
      10             : 
      11             : #include "mozilla/TimeStamp.h"
      12             : #include <stdio.h>
      13             : #include <string.h>
      14             : 
      15             : namespace mozilla {
      16             : 
      17             : /**
      18             :  * Wrapper class used to initialize static data used by the TimeStamp class
      19             :  */
      20             : struct TimeStampInitialization
      21             : {
      22             :   /**
      23             :    * First timestamp taken when the class static initializers are run. This
      24             :    * timestamp is used to sanitize timestamps coming from different sources.
      25             :    */
      26             :   TimeStamp mFirstTimeStamp;
      27             : 
      28             :   /**
      29             :    * Timestamp representing the time when the process was created. This field
      30             :    * is populated lazily the first time this information is required and is
      31             :    * replaced every time the process is restarted.
      32             :    */
      33             :   TimeStamp mProcessCreation;
      34             : 
      35           3 :   TimeStampInitialization()
      36           3 :   {
      37           3 :     TimeStamp::Startup();
      38           3 :     mFirstTimeStamp = TimeStamp::Now();
      39           3 :   };
      40             : 
      41           0 :   ~TimeStampInitialization()
      42           0 :   {
      43           0 :     TimeStamp::Shutdown();
      44           0 :   };
      45             : };
      46             : 
      47           3 : static TimeStampInitialization sInitOnce;
      48             : 
      49             : MFBT_API TimeStamp
      50         782 : TimeStamp::ProcessCreation(bool* aIsInconsistent)
      51             : {
      52         782 :   if (aIsInconsistent) {
      53          13 :     *aIsInconsistent = false;
      54             :   }
      55             : 
      56         782 :   if (sInitOnce.mProcessCreation.IsNull()) {
      57           3 :     char* mozAppRestart = getenv("MOZ_APP_RESTART");
      58           3 :     TimeStamp ts;
      59             : 
      60             :     /* When calling PR_SetEnv() with an empty value the existing variable may
      61             :      * be unset or set to the empty string depending on the underlying platform
      62             :      * thus we have to check if the variable is present and not empty. */
      63           3 :     if (mozAppRestart && (strcmp(mozAppRestart, "") != 0)) {
      64             :       /* Firefox was restarted, use the first time-stamp we've taken as the new
      65             :        * process startup time. */
      66           0 :       ts = sInitOnce.mFirstTimeStamp;
      67             :     } else {
      68           3 :       TimeStamp now = Now();
      69           3 :       uint64_t uptime = ComputeProcessUptime();
      70             : 
      71           3 :       ts = now - TimeDuration::FromMicroseconds(uptime);
      72             : 
      73           3 :       if ((ts > sInitOnce.mFirstTimeStamp) || (uptime == 0)) {
      74             :         /* If the process creation timestamp was inconsistent replace it with
      75             :          * the first one instead and notify that a telemetry error was
      76             :          * detected. */
      77           0 :         if (aIsInconsistent) {
      78           0 :           *aIsInconsistent = true;
      79             :         }
      80           0 :         ts = sInitOnce.mFirstTimeStamp;
      81             :       }
      82             :     }
      83             : 
      84           3 :     sInitOnce.mProcessCreation = ts;
      85             :   }
      86             : 
      87         782 :   return sInitOnce.mProcessCreation;
      88             : }
      89             : 
      90             : void
      91           0 : TimeStamp::RecordProcessRestart()
      92             : {
      93           0 :   sInitOnce.mProcessCreation = TimeStamp();
      94           0 : }
      95             : 
      96           9 : } // namespace mozilla