Record the return value of NativeLibraryPreloader.loadLibrary in UMA

base/android/library_loader/library_loader_hooks.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/android/library_loader/library_loader_hooks.h"
 
 #include "base/android/command_line_android.h"
 #include "base/android/jni_string.h"
 #include "base/android/library_loader/library_load_from_apk_status_codes.h"
 #include "base/android/library_loader/library_prefetcher.h"
 #include "base/at_exit.h"
 #include "base/metrics/histogram.h"
+#include "base/metrics/sparse_histogram.h"
 #include "jni/LibraryLoader_jni.h"
 
 namespace base {
 namespace android {
 
 namespace {
 
 base::AtExitManager* g_at_exit_manager = NULL;
 const char* g_library_version_number = "";
 LibraryLoadedHook* g_registration_callback = NULL;
@@ skipping 18 matching lines @@
 
   // Low-memory browser loads at fixed address, success or fail.
   LOW_MEMORY_LFA_SUCCESS = 1,
   LOW_MEMORY_LFA_BACKOFF_USED = 2,
 
   MAX_BROWSER_HISTOGRAM_CODE = 3,
 };
 
 RendererHistogramCode g_renderer_histogram_code = NO_PENDING_HISTOGRAM_CODE;
 
+// Indicate whether g_library_preloader_renderer_histogram_code is valid
+bool g_library_preloader_renderer_histogram_code_registered = false;
+
+// The return value of NativeLibraryPreloader.loadLibrary() in child processes.
+int g_library_preloader_renderer_histogram_code = 0;
+
 // The amount of time, in milliseconds, that it took to load the shared
 // libraries in the renderer. Set in
 // RegisterChromiumAndroidLinkerRendererHistogram.
 long g_renderer_library_load_time_ms = 0;
 
 } // namespace
 
 static void RegisterChromiumAndroidLinkerRendererHistogram(
     JNIEnv* env,
     const JavaParamRef<jobject>& jcaller,
     jboolean requested_shared_relro,
     jboolean load_at_fixed_address_failed,
     jlong library_load_time_ms) {
   // Note a pending histogram value for later recording.
   if (requested_shared_relro) {
     g_renderer_histogram_code = load_at_fixed_address_failed
                                 ? LFA_BACKOFF_USED : LFA_SUCCESS;
   } else {
     g_renderer_histogram_code = LFA_NOT_ATTEMPTED;
   }
 
   g_renderer_library_load_time_ms = library_load_time_ms;
 }
 
-void RecordChromiumAndroidLinkerRendererHistogram() {
+static void RecordChromiumAndroidLinkerRendererHistogram() {

[Alexei Svitkine (slow), 2016/05/26 19:14:11]

If you only call it locally in the file, put it in the anon namespace above
instead. Also, seems like you can simplify this function name as well.

[michaelbai, 2016/05/26 19:38:51]

Moved to anon namespace, but the name is correct.

   if (g_renderer_histogram_code == NO_PENDING_HISTOGRAM_CODE)
     return;
   // Record and release the pending histogram value.
   UMA_HISTOGRAM_ENUMERATION("ChromiumAndroidLinker.RendererStates",
                             g_renderer_histogram_code,
                             MAX_RENDERER_HISTOGRAM_CODE);
   g_renderer_histogram_code = NO_PENDING_HISTOGRAM_CODE;
 
   // Record how long it took to load the shared libraries.
   UMA_HISTOGRAM_TIMES("ChromiumAndroidLinker.RendererLoadTime",
@@ skipping 23 matching lines @@
   // Record the device support for loading a library directly from the APK file.
   UMA_HISTOGRAM_ENUMERATION("ChromiumAndroidLinker.LibraryLoadFromApkStatus",
                             library_load_from_apk_status,
                             LIBRARY_LOAD_FROM_APK_STATUS_CODES_MAX);
 
   // Record how long it took to load the shared libraries.
   UMA_HISTOGRAM_TIMES("ChromiumAndroidLinker.BrowserLoadTime",
                       base::TimeDelta::FromMilliseconds(library_load_time_ms));
 }
 
+static void RecordLibraryPreloaderBrowserHistogram(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& jcaller,
+    jint status) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY(
+      "Android.NativeLibraryPreloader.Result.Browser",
+      status);
+}
+
+static void RegisterLibraryPreloaderRendererHistogram(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& jcaller,
+    jint status) {
+  g_library_preloader_renderer_histogram_code = status;
+  g_library_preloader_renderer_histogram_code_registered = true;
+}
+
+static void RecordLibraryPreloaderRendereHistogram() {

[Alexei Svitkine (slow), 2016/05/26 19:14:11]

Put this in the anon namespace above.

[michaelbai, 2016/05/26 19:38:51]

Moved to anon namespace.

+  if (g_library_preloader_renderer_histogram_code_registered) {
+    UMA_HISTOGRAM_SPARSE_SLOWLY(
+        "Android.NativeLibraryPreloader.Result.Renderer",
+        g_library_preloader_renderer_histogram_code);
+  }
+}
+
+void RecordLibraryLoaderRendererHistogram() {

[Alexei Svitkine (slow), 2016/05/26 19:14:11]

This is recording multiple histograms right? Make the name plural.

[michaelbai, 2016/05/26 19:38:51]

Done.

+  RecordChromiumAndroidLinkerRendererHistogram();
+  RecordLibraryPreloaderRendereHistogram();
+}
+
 void SetLibraryLoadedHook(LibraryLoadedHook* func) {
   g_registration_callback = func;
 }
 
 static void InitCommandLine(
     JNIEnv* env,
     const JavaParamRef<jobject>& jcaller,
     const JavaParamRef<jobjectArray>& init_command_line) {
   InitNativeCommandLineFromJavaArray(env, init_command_line);
 }
@@ skipping 43 matching lines @@
   return static_cast<LibraryProcessType>(
       Java_LibraryLoader_getLibraryProcessType(env));
 }
 
 void InitAtExitManager() {
   g_at_exit_manager = new base::AtExitManager();
 }
 
 }  // namespace android
 }  // namespace base