Bug 1568514 - Add telemetry histograms to report hyphenation memory footprint and resource load times. r=heycam

Differential Revision: https://phabricator.services.mozilla.com/D39323

--HG--
extra : moz-landing-system : lando

intl/hyphenation/glue/nsHyphenationManager.cpp

@@ -18,6 +18,7 @@
 #include "mozilla/Preferences.h"
 #include "nsZipArchive.h"
 #include "mozilla/Services.h"
+#include "mozilla/Telemetry.h"
 #include "nsIObserverService.h"
 #include "nsCRT.h"
 #include "nsAppDirectoryServiceDefs.h"
@@ -29,6 +30,13 @@ using namespace mozilla;
 static const char kIntlHyphenationAliasPrefix[] = "intl.hyphenation-alias.";
 static const char kMemoryPressureNotification[] = "memory-pressure";
 
+// To report memory usage via telemetry, we observe a notification when the
+// process is about to be shut down; unfortunately, parent and child processes
+// receive different notifications, so we have to account for that in order to
+// report usage from both process types.
+static const char kParentShuttingDownNotification[] = "profile-before-change";
+static const char kChildShuttingDownNotification[] = "content-child-shutdown";
+
 class HyphenReporter final : public nsIMemoryReporter,
                              public CountingAllocatorBase<HyphenReporter> {
  private:
@@ -37,6 +45,11 @@ class HyphenReporter final : public nsIMemoryReporter,
  public:
   NS_DECL_ISUPPORTS
 
+  // For telemetry, we report the memory rounded up to the nearest KB.
+  static uint32_t MemoryAllocatedInKB() {
+    return (MemoryAllocated() + 1023) / 1024;
+  }
+
   NS_IMETHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData, bool aAnonymize) override {
     size_t total = MemoryAllocated();
@@ -78,20 +91,21 @@ void hnj_free(void* aPtr) { HyphenReporter::CountingFree(aPtr); }
 
 nsHyphenationManager* nsHyphenationManager::sInstance = nullptr;
 
-NS_IMPL_ISUPPORTS(nsHyphenationManager::MemoryPressureObserver, nsIObserver)
+NS_IMPL_ISUPPORTS(nsHyphenationManager, nsIObserver)
 
 NS_IMETHODIMP
-nsHyphenationManager::MemoryPressureObserver::Observe(nsISupports* aSubject,
-                                                      const char* aTopic,
-                                                      const char16_t* aData) {
+nsHyphenationManager::Observe(nsISupports* aSubject, const char* aTopic,
+                              const char16_t* aData) {
   if (!nsCRT::strcmp(aTopic, kMemoryPressureNotification)) {
-    // We don't call Instance() here, as we don't want to create a hyphenation
-    // manager if there isn't already one in existence.
-    // (This observer class is local to the hyphenation manager, so it can use
-    // the protected members directly.)
-    if (nsHyphenationManager::sInstance) {
-      nsHyphenationManager::sInstance->mHyphenators.Clear();
-    }
+    // We're going to discard hyphenators; record a telemetry entry for the
+    // memory usage we reached before doing so.
+    Telemetry::Accumulate(Telemetry::HYPHENATION_MEMORY,
+                          HyphenReporter::MemoryAllocatedInKB());
+    nsHyphenationManager::sInstance->mHyphenators.Clear();
+  } else if (!nsCRT::strcmp(aTopic, kParentShuttingDownNotification) ||
+             !nsCRT::strcmp(aTopic, kChildShuttingDownNotification)) {
+    Telemetry::Accumulate(Telemetry::HYPHENATION_MEMORY,
+                          HyphenReporter::MemoryAllocatedInKB());
   }
   return NS_OK;
 }
@@ -102,7 +116,10 @@ nsHyphenationManager* nsHyphenationManager::Instance() {
 
     nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
     if (obs) {
-      obs->AddObserver(new MemoryPressureObserver, kMemoryPressureNotification,
+      obs->AddObserver(sInstance, kMemoryPressureNotification, false);
+      obs->AddObserver(sInstance,
+                       XRE_IsParentProcess() ? kParentShuttingDownNotification
+                                             : kChildShuttingDownNotification,
                        false);
     }
 
@@ -112,8 +129,17 @@ nsHyphenationManager* nsHyphenationManager::Instance() {
 }
 
 void nsHyphenationManager::Shutdown() {
-  delete sInstance;
-  sInstance = nullptr;
+  if (sInstance) {
+    nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+    if (obs) {
+      obs->RemoveObserver(sInstance, kMemoryPressureNotification);
+      obs->RemoveObserver(sInstance, XRE_IsParentProcess()
+                                         ? kParentShuttingDownNotification
+                                         : kChildShuttingDownNotification);
+    }
+    delete sInstance;
+    sInstance = nullptr;
+  }
 }
 
 nsHyphenationManager::nsHyphenationManager() {

intl/hyphenation/glue/nsHyphenationManager.h

@@ -16,8 +16,11 @@ class nsHyphenator;
 class nsAtom;
 class nsIURI;
 
-class nsHyphenationManager {
+class nsHyphenationManager : public nsIObserver {
  public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
   nsHyphenationManager();
 
   already_AddRefed<nsHyphenator> GetHyphenator(nsAtom* aLocale);
@@ -29,17 +32,9 @@ class nsHyphenationManager {
   size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);
 
  private:
-  ~nsHyphenationManager();
+  virtual ~nsHyphenationManager();
 
  protected:
-  class MemoryPressureObserver final : public nsIObserver {
-    ~MemoryPressureObserver() {}
-
-   public:
-    NS_DECL_ISUPPORTS
-    NS_DECL_NSIOBSERVER
-  };
-
   void LoadPatternList();
   void LoadPatternListFromOmnijar(mozilla::Omnijar::Type aType);
   void LoadPatternListFromDir(nsIFile* aDir);

intl/hyphenation/glue/nsHyphenator.cpp

@@ -8,6 +8,7 @@
 #include "nsUTF8Utils.h"
 #include "nsUnicodeProperties.h"
 #include "nsIURI.h"
+#include "mozilla/Telemetry.h"
 
 #include "hyphen.h"
 
@@ -18,6 +19,7 @@ nsHyphenator::nsHyphenator(nsIURI* aURI, bool aHyphenateCapitalized)
   if (NS_FAILED(rv)) {
     return;
   }
+  Telemetry::AutoTimer<Telemetry::HYPHENATION_LOAD_TIME> telemetry;
   mDict = hnj_hyphen_load(uriSpec.get());
 #ifdef DEBUG
   if (mDict) {

toolkit/components/telemetry/Histograms.json

@@ -15669,5 +15669,29 @@
       "high": 100,
       "n_buckets": 12,
       "description": "Percentages of times for phases in an expensive refresh tick relative to the time spent in the entire tick (REFRESH_DRIVER_TICK)."
+  },
+  "HYPHENATION_MEMORY": {
+    "record_in_processes": ["main", "content"],
+    "products": ["firefox", "fennec", "geckoview"],
+    "alert_emails": ["jkew@mozilla.com"],
+    "bug_numbers": [1568514],
+    "expires_in_version": "74",
+    "kind": "exponential",
+    "high": 8000,
+    "n_buckets": 100,
+    "releaseChannelCollection": "opt-out",
+    "description": "Total per-process memory used by loaded auto-hyphenation tables (KB)."
+  },
+  "HYPHENATION_LOAD_TIME": {
+    "record_in_processes": ["main", "content"],
+    "products": ["firefox", "fennec", "geckoview"],
+    "alert_emails": ["jkew@mozilla.com"],
+    "bug_numbers": [1568514],
+    "expires_in_version": "74",
+    "kind": "exponential",
+    "high": 1000,
+    "n_buckets": 100,
+    "releaseChannelCollection": "opt-out",
+    "description": "How many milliseconds it took to load a hyphenation resource."
   }
 }