michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim:set ts=2 sw=2 sts=2 et cindent: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * Implementation of the OS-independent methods of the TimeStamp class
michael@0:  */
michael@0: 
michael@0: #include "mozilla/TimeStamp.h"
michael@0: #include "prenv.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: /**
michael@0:  * Wrapper class used to initialize static data used by the TimeStamp class
michael@0:  */
michael@0: struct TimeStampInitialization {
michael@0:   /**
michael@0:    * First timestamp taken when the class static initializers are run. This
michael@0:    * timestamp is used to sanitize timestamps coming from different sources.
michael@0:    */
michael@0:   TimeStamp mFirstTimeStamp;
michael@0: 
michael@0:   /**
michael@0:    * Timestamp representing the time when the process was created. This field
michael@0:    * is populated lazily the first time this information is required and is
michael@0:    * replaced every time the process is restarted.
michael@0:    */
michael@0:   TimeStamp mProcessCreation;
michael@0: 
michael@0:   TimeStampInitialization() {
michael@0:     TimeStamp::Startup();
michael@0:     mFirstTimeStamp = TimeStamp::Now();
michael@0:   };
michael@0: 
michael@0:   ~TimeStampInitialization() {
michael@0:     TimeStamp::Shutdown();
michael@0:   };
michael@0: };
michael@0: 
michael@0: static TimeStampInitialization sInitOnce;
michael@0: 
michael@0: TimeStamp
michael@0: TimeStamp::ProcessCreation(bool& aIsInconsistent)
michael@0: {
michael@0:   aIsInconsistent = false;
michael@0: 
michael@0:   if (sInitOnce.mProcessCreation.IsNull()) {
michael@0:     char *mozAppRestart = PR_GetEnv("MOZ_APP_RESTART");
michael@0:     TimeStamp ts;
michael@0: 
michael@0:     /* When calling PR_SetEnv() with an empty value the existing variable may
michael@0:      * be unset or set to the empty string depending on the underlying platform
michael@0:      * thus we have to check if the variable is present and not empty. */
michael@0:     if (mozAppRestart && (strcmp(mozAppRestart, "") != 0)) {
michael@0:       /* Firefox was restarted, use the first time-stamp we've taken as the new
michael@0:        * process startup time. */
michael@0:       ts = sInitOnce.mFirstTimeStamp;
michael@0:     } else {
michael@0:       TimeStamp now = Now();
michael@0:       uint64_t uptime = ComputeProcessUptime();
michael@0: 
michael@0:       ts = now - TimeDuration::FromMicroseconds(uptime);
michael@0: 
michael@0:       if ((ts > sInitOnce.mFirstTimeStamp) || (uptime == 0)) {
michael@0:         /* If the process creation timestamp was inconsistent replace it with
michael@0:          * the first one instead and notify that a telemetry error was
michael@0:          * detected. */
michael@0:         aIsInconsistent = true;
michael@0:         ts = sInitOnce.mFirstTimeStamp;
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     sInitOnce.mProcessCreation = ts;
michael@0:   }
michael@0: 
michael@0:   return sInitOnce.mProcessCreation;
michael@0: }
michael@0: 
michael@0: void
michael@0: TimeStamp::RecordProcessRestart()
michael@0: {
michael@0:   sInitOnce.mProcessCreation = TimeStamp();
michael@0: }
michael@0: 
michael@0: } // namespace mozilla