1 files changed, 17 insertions, 219 deletions

diff --git a/toolkit/components/terminator/nsTerminator.cpp b/toolkit/components/terminator/nsTerminator.cpp
index 5a1f9693b8..6339962022 100644
--- a/toolkit/components/terminator/nsTerminator.cpp
+++ b/toolkit/components/terminator/nsTerminator.cpp
@@ -245,131 +245,9 @@ void RunWatchdog(void* arg) {
   }
 }
 
-////////////////////////////////////////////
-//
-// Writer thread
-//
-// This nspr thread is in charge of writing to disk statistics produced by the
-// watchdog thread and collected by the main thread. Note that we use a nspr
-// thread rather than usual XPCOM I/O simply because we outlive XPCOM and its
-// threads.
-//
-
-//
-// Communication between the main thread and the writer thread.
-//
-// Main thread:
-//
-// * Whenever a shutdown step has been completed, the main thread
-// obtains the number of ticks from the watchdog threads, builds
-// a string representing all the data gathered so far, places
-// this string in `gWriteData`, and wakes up the writer thread
-// using `gWriteReady`. If `gWriteData` already contained a non-null
-// pointer, this means that the writer thread is lagging behind the
-// main thread, and the main thread cleans up the memory.
-//
-// Writer thread:
-//
-// * When awake, the writer thread swaps `gWriteData` to nullptr. If
-// `gWriteData` contained data to write, the . If so, the writer
-// thread writes the data to a file named "ShutdownDuration.json.tmp",
-// then moves that file to "ShutdownDuration.json" and cleans up the
-// data. If `gWriteData` contains a nullptr, the writer goes to sleep
-// until it is awkened using `gWriteReady`.
-//
-//
-// The data written by the writer thread will be read by another
-// module upon the next restart and fed to Telemetry.
-//
-Atomic<nsCString*> gWriteData(nullptr);
-PRMonitor* gWriteReady = nullptr;
-
-void RunWriter(void* arg) {
-  AUTO_PROFILER_REGISTER_THREAD("Shutdown Statistics Writer");
-  NS_SetCurrentThreadName("Shutdown Statistics Writer");
-
-  MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(arg);
-  // Shutdown will generally complete before we have a chance to
-  // deallocate. This is not a leak.
-
-  // Setup destinationPath and tmpFilePath
-
-  nsCString destinationPath;
-  destinationPath.Adopt(static_cast<char*>(arg));
-  nsAutoCString tmpFilePath;
-  tmpFilePath.Append(destinationPath);
-  tmpFilePath.AppendLiteral(".tmp");
-
-  // Cleanup any file leftover from a previous run
-  Unused << PR_Delete(tmpFilePath.get());
-  Unused << PR_Delete(destinationPath.get());
-
-  while (true) {
-    //
-    // Check whether we have received data from the main thread.
-    //
-    // We perform the check before waiting on `gWriteReady` as we may
-    // have received data while we were busy writing.
-    //
-    // Also note that gWriteData may have been modified several times
-    // since we last checked. That's ok, we are not losing any important
-    // data (since we keep adding data), and we are not leaking memory
-    // (since the main thread deallocates any data that hasn't been
-    // consumed by the writer thread).
-    //
-    UniquePtr<nsCString> data(gWriteData.exchange(nullptr));
-    if (!data) {
-      // Data is not available yet.
-      // Wait until the main thread provides it.
-      PR_EnterMonitor(gWriteReady);
-      PR_Wait(gWriteReady, PR_INTERVAL_NO_TIMEOUT);
-      PR_ExitMonitor(gWriteReady);
-      continue;
-    }
-
-    MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(data.get());
-    // Shutdown may complete before we have a chance to deallocate.
-    // This is not a leak.
-
-    //
-    // Write to a temporary file
-    //
-    // In case of any error, we simply give up. Since the data is
-    // hardly critical, we don't want to spend too much effort
-    // salvaging it.
-    //
-    UniquePtr<PRFileDesc, PR_CloseDelete> tmpFileDesc(PR_Open(
-        tmpFilePath.get(), PR_WRONLY | PR_TRUNCATE | PR_CREATE_FILE, 00600));
-
-    // Shutdown may complete before we have a chance to close the file.
-    // This is not a leak.
-    MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(tmpFileDesc.get());
-
-    if (tmpFileDesc == nullptr) {
-      break;
-    }
-    if (PR_Write(tmpFileDesc.get(), data->get(), data->Length()) == -1) {
-      break;
-    }
-    tmpFileDesc.reset();
-
-    //
-    // Rename on top of destination file.
-    //
-    // This is not sufficient to guarantee that the destination file
-    // will be written correctly, but, again, we don't care enough
-    // about the data to make more efforts.
-    //
-    Unused << PR_Delete(destinationPath.get());
-    if (PR_Rename(tmpFilePath.get(), destinationPath.get()) != PR_SUCCESS) {
-      break;
-    }
-  }
-}
-
 }  // namespace
 
-NS_IMPL_ISUPPORTS(nsTerminator, nsIObserver)
+NS_IMPL_ISUPPORTS(nsTerminator, nsIObserver, nsITerminatorTest)
 
 nsTerminator::nsTerminator() : mInitialized(false), mCurrentStep(-1) {}
 
@@ -379,12 +257,6 @@ void nsTerminator::Start() {
   MOZ_ASSERT(!mInitialized);
 
   StartWatchdog();
-#if !defined(NS_FREE_PERMANENT_DATA)
-  // Only allow nsTerminator to write on non-leak-checked builds so we don't
-  // get leak warnings on shutdown for intentional leaks (see bug 1242084).
-  // This will be enabled again by bug 1255484 when 1255478 lands.
-  StartWriter();
-#endif  // !defined(NS_FREE_PERMANENT_DATA)
   mInitialized = true;
 }
 
@@ -470,41 +342,6 @@ void nsTerminator::StartWatchdog() {
   MOZ_ASSERT(watchdogThread);
 }
 
-// Prepare, allocate and start the writer thread. By design, it will never
-// finish, nor be deallocated. In case of error, we degrade
-// gracefully to not writing Telemetry data.
-void nsTerminator::StartWriter() {
-  if (!Telemetry::CanRecordExtended()) {
-    return;
-  }
-  nsCOMPtr<nsIFile> profLD;
-  nsresult rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_LOCAL_50_DIR,
-                                       getter_AddRefs(profLD));
-  if (NS_FAILED(rv)) {
-    return;
-  }
-
-  rv = profLD->Append(u"ShutdownDuration.json"_ns);
-  if (NS_FAILED(rv)) {
-    return;
-  }
-
-  nsAutoString path;
-  rv = profLD->GetPath(path);
-  if (NS_FAILED(rv)) {
-    return;
-  }
-
-  gWriteReady = PR_NewMonitor();
-  MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(
-      gWriteReady);  // We will never deallocate this object
-  PRThread* writerThread = CreateSystemThread(RunWriter, ToNewUTF8String(path));
-
-  if (!writerThread) {
-    return;
-  }
-}
-
 // This helper is here to preserve the existing crash reporting behavior
 // based on observer topic names, using the shutdown phase name only for
 // phases without associated topic.
@@ -531,12 +368,6 @@ void nsTerminator::AdvancePhase(mozilla::ShutdownPhase aPhase) {
   }
 
   UpdateHeartbeat(step);
-#if !defined(NS_FREE_PERMANENT_DATA)
-  // Only allow nsTerminator to write on non-leak checked builds so we don't get
-  // leak warnings on shutdown for intentional leaks (see bug 1242084). This
-  // will be enabled again by bug 1255484 when 1255478 lands.
-  UpdateTelemetry();
-#endif  // !defined(NS_FREE_PERMANENT_DATA)
   UpdateCrashReport(GetReadableNameForPhase(aPhase));
 }
 
@@ -555,58 +386,25 @@ void nsTerminator::UpdateHeartbeat(int32_t aStep) {
   }
 }
 
-void nsTerminator::UpdateTelemetry() {
-  if (!Telemetry::CanRecordExtended() || !gWriteReady) {
-    return;
-  }
-
-  //
-  // We need Telemetry data on the effective duration of each step,
-  // to be able to tune the time-to-crash of each of both the
-  // Terminator and AsyncShutdown. However, at this stage, it is too
-  // late to record such data into Telemetry, so we write it to disk
-  // and read it upon the next startup.
-  //
-
-  // Build JSON.
-  UniquePtr<nsCString> telemetryData(new nsCString());
-  telemetryData->AppendLiteral("{");
-  size_t fields = 0;
-  for (auto& shutdownStep : sShutdownSteps) {
-    if (shutdownStep.mTicks < 0) {
-      // Ignore this field.
-      continue;
-    }
-    if (fields++ > 0) {
-      telemetryData->AppendLiteral(", ");
-    }
-    telemetryData->AppendLiteral(R"(")");
-    telemetryData->Append(GetReadableNameForPhase(shutdownStep.mPhase));
-    telemetryData->AppendLiteral(R"(": )");
-    telemetryData->AppendInt(shutdownStep.mTicks);
-  }
-  telemetryData->AppendLiteral("}");
-
-  if (fields == 0) {
-    // Nothing to write
-    return;
-  }
-
-  //
-  // Send data to the worker thread.
-  //
-  delete gWriteData.exchange(
-      telemetryData.release());  // Clear any data that hasn't been written yet
-
-  // In case the worker thread was sleeping, wake it up.
-  PR_EnterMonitor(gWriteReady);
-  PR_Notify(gWriteReady);
-  PR_ExitMonitor(gWriteReady);
-}
-
 void nsTerminator::UpdateCrashReport(const char* aTopic) {
   // In case of crash, we wish to know where in shutdown we are
   CrashReporter::RecordAnnotationCString(
       CrashReporter::Annotation::ShutdownProgress, aTopic);
 }
+
+NS_IMETHODIMP
+nsTerminator::GetTicksForShutdownPhases(JSContext* aCx,
+                                        JS::MutableHandle<JS::Value> aRetval) {
+  JS::Rooted<JSObject*> obj(aCx, JS_NewPlainObject(aCx));
+  aRetval.setObject(*obj);
+
+  for (auto& shutdownStep : sShutdownSteps) {
+    if (shutdownStep.mTicks >= 0) {
+      JS_DefineProperty(aCx, obj, GetReadableNameForPhase(shutdownStep.mPhase),
+                        shutdownStep.mTicks, JSPROP_ENUMERATE);
+    }
+  }
+
+  return NS_OK;
+}  // namespace mozilla
 }  // namespace mozilla