Bug 815709 - Shutdown time is read in the main thread. r=ehsan.

Move code to Telemetry.cpp and s/NULL/nullptr/.

toolkit/components/startup/StartupTimeline.h

@@ -40,6 +40,7 @@ NS_VISIBILITY_DEFAULT __attribute__((weak));
 namespace mozilla {
 
 void RecordShutdownEndTimeStamp();
+void RecordShutdownStartTimeStamp();
 
 class StartupTimeline {
 public:

toolkit/components/startup/nsAppStartup.cpp

@@ -163,9 +163,7 @@ nsAppStartup::nsAppStartup() :
   mRestart(false),
   mInterrupted(false),
   mIsSafeModeNecessary(false),
-  mStartupCrashTrackingEnded(false),
-  mCachedShutdownTime(false),
-  mLastShutdownTime(0)
+  mStartupCrashTrackingEnded(false)
 { }
 
 
@@ -296,83 +294,7 @@ nsAppStartup::Run(void)
   return mRestart ? NS_SUCCESS_RESTART_APP : NS_OK;
 }
 
-static TimeStamp gRecordedShutdownStartTime;
-static bool gAlreadyFreedShutdownTimeFileName = false;
-static char *gRecordedShutdownTimeFileName = NULL;
 
-static char *
-GetShutdownTimeFileName()
-{
-  if (gAlreadyFreedShutdownTimeFileName) {
-    return NULL;
-  }
-
-  if (!gRecordedShutdownTimeFileName) {
-    nsCOMPtr<nsIFile> mozFile;
-    NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(mozFile));
-    if (!mozFile)
-      return NULL;
-
-    mozFile->AppendNative(NS_LITERAL_CSTRING("Telemetry.ShutdownTime.txt"));
-    nsAutoCString nativePath;
-    nsresult rv = mozFile->GetNativePath(nativePath);
-    if (!NS_SUCCEEDED(rv))
-      return NULL;
-
-    gRecordedShutdownTimeFileName = PL_strdup(nativePath.get());
-  }
-
-  return gRecordedShutdownTimeFileName;
-}
-
-static void
-RecordShutdownStartTimeStamp() {
-  if (!Telemetry::CanRecord())
-    return;
-
-  gRecordedShutdownStartTime = TimeStamp::Now();
-
-  GetShutdownTimeFileName();
-}
-
-namespace mozilla {
-void
-RecordShutdownEndTimeStamp() {
-  if (!gRecordedShutdownTimeFileName || gAlreadyFreedShutdownTimeFileName)
-    return;
-
-  nsCString name(gRecordedShutdownTimeFileName);
-  PL_strfree(gRecordedShutdownTimeFileName);
-  gRecordedShutdownTimeFileName = NULL;
-  gAlreadyFreedShutdownTimeFileName = true;
-
-  nsCString tmpName = name;
-  tmpName += ".tmp";
-  FILE *f = fopen(tmpName.get(), "w");
-  if (!f)
-    return;
-  // On a normal release build this should be called just before
-  // calling _exit, but on a debug build or when the user forces a full
-  // shutdown this is called as late as possible, so we have to
-  // white list this write as write poisoning will be enabled.
-  int fd = fileno(f);
-  MozillaRegisterDebugFD(fd);
-
-  TimeStamp now = TimeStamp::Now();
-  MOZ_ASSERT(now >= gRecordedShutdownStartTime);
-  TimeDuration diff = now - gRecordedShutdownStartTime;
-  uint32_t diff2 = diff.ToMilliseconds();
-  int written = fprintf(f, "%d\n", diff2);
-  MozillaUnRegisterDebugFILE(f);
-  int rv = fclose(f);
-  if (written < 0 || rv != 0) {
-    PR_Delete(tmpName.get());
-    return;
-  }
-  PR_Delete(name.get());
-  PR_Rename(tmpName.get(), name.get());
-}
-}
 
 NS_IMETHODIMP
 nsAppStartup::Quit(uint32_t aMode)
@@ -389,7 +311,7 @@ nsAppStartup::Quit(uint32_t aMode)
     return NS_OK;
 
   SAMPLE_MARKER("Shutdown start");
-  RecordShutdownStartTimeStamp();
+  mozilla::RecordShutdownStartTimeStamp();
 
   // If we're considering quitting, we will only do so if:
   if (ferocity == eConsiderQuit) {
@@ -588,47 +510,6 @@ nsAppStartup::ExitLastWindowClosingSurvivalArea(void)
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsAppStartup::GetLastShutdownDuration(uint32_t *aResult)
-{
-  // We make this check so that GetShutdownTimeFileName() doesn't get
-  // called; calling that function without telemetry enabled violates
-  // assumptions that the write-the-shutdown-timestamp machinery makes.
-  if (!Telemetry::CanRecord()) {
-    *aResult = 0;
-    return NS_OK;
-  }
-
-  if (!mCachedShutdownTime) {
-    const char *filename = GetShutdownTimeFileName();
-
-    if (!filename) {
-      *aResult = 0;
-      return NS_OK;
-    }
-
-    FILE *f = fopen(filename, "r");
-    if (!f) {
-      *aResult = 0;
-      return NS_OK;
-    }
-
-    int shutdownTime;
-    int r = fscanf(f, "%d\n", &shutdownTime);
-    fclose(f);
-    if (r != 1) {
-      *aResult = 0;
-      return NS_OK;
-    }
-
-    mLastShutdownTime = shutdownTime;
-    mCachedShutdownTime = true;
-  }
-
-  *aResult = mLastShutdownTime;
-  return NS_OK;
-}
-
 //
 // nsAppStartup->nsIAppStartup2
 //

toolkit/components/startup/nsAppStartup.h

@@ -61,8 +61,6 @@ private:
   bool mInterrupted;    // Was startup interrupted by an interactive prompt?
   bool mIsSafeModeNecessary;       // Whether safe mode is necessary
   bool mStartupCrashTrackingEnded; // Whether startup crash tracking has already ended
-  bool mCachedShutdownTime;
-  uint32_t mLastShutdownTime;
 
 #if defined(XP_WIN)
   //Interaction with OS-provided profiling probes

toolkit/components/startup/public/nsIAppStartup.idl

@@ -7,7 +7,7 @@
 
 interface nsICmdLineService;
 
-[scriptable, uuid(5016bc45-54d9-4f97-935c-df4cef4b999f)]
+[scriptable, uuid(2b51b67f-6f05-4145-b37e-7369bbc92b19)]
 interface nsIAppStartup : nsISupports
 {
     /**
@@ -42,12 +42,6 @@ interface nsIAppStartup : nsISupports
     void enterLastWindowClosingSurvivalArea();
     void exitLastWindowClosingSurvivalArea();
 
-    /**
-     * The amount of time, in milliseconds, that the last session took
-     * to shutdown.  Reads as 0 to indicate failure.
-     */
-    readonly attribute uint32_t lastShutdownDuration;
-
     /**
      * Startup Crash Detection
      *

toolkit/components/telemetry/Telemetry.cpp

@@ -24,12 +24,15 @@
 #include "nsBaseHashtable.h"
 #include "nsXULAppAPI.h"
 #include "nsThreadUtils.h"
+#include "plstr.h"
+#include "nsAppDirectoryServiceDefs.h"
 #include "mozilla/ProcessedStack.h"
 #include "mozilla/Mutex.h"
 #include "mozilla/FileUtils.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/Likely.h"
+#include "mozilla/mozPoisonWrite.h"
 
 namespace {
 
@@ -313,6 +316,9 @@ private:
   HangReports mHangReports;
   Mutex mHangReportsMutex;
   nsIMemoryReporter *mMemoryReporter;
+
+  bool mCachedShutdownTime;
+  uint32_t mLastShutdownTime;
 };
 
 TelemetryImpl*  TelemetryImpl::sTelemetry = NULL;
@@ -680,11 +686,83 @@ WrapAndReturnHistogram(Histogram *h, JSContext *cx, jsval *ret)
   return NS_OK;
 }
 
+static TimeStamp gRecordedShutdownStartTime;
+static bool gAlreadyFreedShutdownTimeFileName = false;
+static char *gRecordedShutdownTimeFileName = nullptr;
+
+static char *
+GetShutdownTimeFileName()
+{
+  if (gAlreadyFreedShutdownTimeFileName) {
+    return nullptr;
+  }
+
+  if (!gRecordedShutdownTimeFileName) {
+    nsCOMPtr<nsIFile> mozFile;
+    NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(mozFile));
+    if (!mozFile)
+      return nullptr;
+
+    mozFile->AppendNative(NS_LITERAL_CSTRING("Telemetry.ShutdownTime.txt"));
+    nsAutoCString nativePath;
+    nsresult rv = mozFile->GetNativePath(nativePath);
+    if (!NS_SUCCEEDED(rv))
+      return nullptr;
+
+    gRecordedShutdownTimeFileName = PL_strdup(nativePath.get());
+  }
+
+  return gRecordedShutdownTimeFileName;
+}
+
+NS_IMETHODIMP
+TelemetryImpl::GetLastShutdownDuration(uint32_t *aResult)
+{
+  // We make this check so that GetShutdownTimeFileName() doesn't get
+  // called; calling that function without telemetry enabled violates
+  // assumptions that the write-the-shutdown-timestamp machinery makes.
+  if (!Telemetry::CanRecord()) {
+    *aResult = 0;
+    return NS_OK;
+  }
+
+  if (!mCachedShutdownTime) {
+    const char *filename = GetShutdownTimeFileName();
+
+    if (!filename) {
+      *aResult = 0;
+      return NS_OK;
+    }
+
+    FILE *f = fopen(filename, "r");
+    if (!f) {
+      *aResult = 0;
+      return NS_OK;
+    }
+
+    int shutdownTime;
+    int r = fscanf(f, "%d\n", &shutdownTime);
+    fclose(f);
+    if (r != 1) {
+      *aResult = 0;
+      return NS_OK;
+    }
+
+    mLastShutdownTime = shutdownTime;
+    mCachedShutdownTime = true;
+  }
+
+  *aResult = mLastShutdownTime;
+  return NS_OK;
+}
+
 TelemetryImpl::TelemetryImpl():
 mHistogramMap(Telemetry::HistogramCount),
 mCanRecord(XRE_GetProcessType() == GeckoProcessType_Default),
 mHashMutex("Telemetry::mHashMutex"),
-mHangReportsMutex("Telemetry::mHangReportsMutex")
+mHangReportsMutex("Telemetry::mHangReportsMutex"),
+mCachedShutdownTime(false),
+mLastShutdownTime(0)
 {
   // A whitelist to prevent Telemetry reporting on Addon & Thunderbird DBs
   const char *trackedDBs[] = {
@@ -1673,6 +1751,53 @@ const Module kTelemetryModule = {
 } // anonymous namespace
 
 namespace mozilla {
+void
+RecordShutdownStartTimeStamp() {
+  if (!Telemetry::CanRecord())
+    return;
+
+  gRecordedShutdownStartTime = TimeStamp::Now();
+
+  GetShutdownTimeFileName();
+}
+
+void
+RecordShutdownEndTimeStamp() {
+  if (!gRecordedShutdownTimeFileName || gAlreadyFreedShutdownTimeFileName)
+    return;
+
+  nsCString name(gRecordedShutdownTimeFileName);
+  PL_strfree(gRecordedShutdownTimeFileName);
+  gRecordedShutdownTimeFileName = nullptr;
+  gAlreadyFreedShutdownTimeFileName = true;
+
+  nsCString tmpName = name;
+  tmpName += ".tmp";
+  FILE *f = fopen(tmpName.get(), "w");
+  if (!f)
+    return;
+  // On a normal release build this should be called just before
+  // calling _exit, but on a debug build or when the user forces a full
+  // shutdown this is called as late as possible, so we have to
+  // white list this write as write poisoning will be enabled.
+  int fd = fileno(f);
+  MozillaRegisterDebugFD(fd);
+
+  TimeStamp now = TimeStamp::Now();
+  MOZ_ASSERT(now >= gRecordedShutdownStartTime);
+  TimeDuration diff = now - gRecordedShutdownStartTime;
+  uint32_t diff2 = diff.ToMilliseconds();
+  int written = fprintf(f, "%d\n", diff2);
+  MozillaUnRegisterDebugFILE(f);
+  int rv = fclose(f);
+  if (written < 0 || rv != 0) {
+    PR_Delete(tmpName.get());
+    return;
+  }
+  PR_Delete(name.get());
+  PR_Rename(tmpName.get(), name.get());
+}
+
 namespace Telemetry {
 
 void

toolkit/components/telemetry/TelemetryPing.js

@@ -147,7 +147,7 @@ function getSimpleMeasurements() {
            .getService(Ci.nsIJSEngineTelemetryStats)
            .telemetryValue;
 
-  let shutdownDuration = Services.startup.lastShutdownDuration;
+  let shutdownDuration = Telemetry.lastShutdownDuration;
   if (shutdownDuration)
     ret.shutdownDuration = shutdownDuration;
 

toolkit/components/telemetry/nsITelemetry.idl

@@ -6,7 +6,7 @@
 #include "nsISupports.idl"
 #include "nsIFile.idl"
 
-[scriptable, uuid(de54f594-4c20-4968-a27a-83b38ff952b9)]
+[scriptable, uuid(420ebbd5-efe3-42f2-8a13-f695e0fdcca0)]
 interface nsITelemetry : nsISupports
 {
   /**
@@ -36,6 +36,12 @@ interface nsITelemetry : nsISupports
   [implicit_jscontext]
   readonly attribute jsval histogramSnapshots;
 
+  /**
+   * The amount of time, in milliseconds, that the last session took
+   * to shutdown.  Reads as 0 to indicate failure.
+   */
+  readonly attribute uint32_t lastShutdownDuration;
+
   /*
    * An object containing information about slow SQL statements.
    *