Linux: Add a UMA for the glibc version.

chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc

 // Copyright (c) 2013 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 "chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.h"
 
 #include <string>
+#include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/cpu.h"
 #include "base/metrics/histogram.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/time.h"
 #include "chrome/browser/about_flags.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_browser_main.h"
 #include "chrome/browser/shell_integration.h"
 #include "content/public/browser/browser_thread.h"
 #include "ui/base/touch/touch_device.h"
 #include "ui/base/ui_base_switches.h"
 
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+#include <gnu/libc-version.h>
+
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#endif
+
 namespace {
 
+enum UMALinuxGlibcVersion {
+  UMA_LINUX_GLIBC_NOT_PARSEABLE,
+  UMA_LINUX_GLIBC_UNKNOWN,
+  UMA_LINUX_GLIBC_2_11,
+  UMA_LINUX_GLIBC_2_19 = UMA_LINUX_GLIBC_2_11 + 8,
+  // NOTE: Add new version above this line and update the enum list in
+  // tools/histograms/histograms.xml accordingly.
+  UMA_LINUX_GLIBC_VERSION_COUNT
+};
+
+// A constant to translate glibc 2.x minor versions to their
+// equivalent UMALinuxGlibcVersion values.
+const unsigned kGlibcMinorVersionTranslationOffset = 11 - UMA_LINUX_GLIBC_2_11;
+
 enum UMATouchEventsState {
   UMA_TOUCH_EVENTS_ENABLED,
   UMA_TOUCH_EVENTS_AUTO_ENABLED,
   UMA_TOUCH_EVENTS_AUTO_DISABLED,
   UMA_TOUCH_EVENTS_DISABLED,
   // NOTE: Add states only immediately above this line. Make sure to
   // update the enum list in tools/histograms/histograms.xml accordingly.
   UMA_TOUCH_EVENTS_STATE_COUNT
 };
 
-void LogIntelMicroArchitecture() {
+void RecordIntelMicroArchitecture() {
 #if defined(ARCH_CPU_X86_FAMILY)
   base::CPU cpu;
   base::CPU::IntelMicroArchitecture arch = cpu.GetIntelMicroArchitecture();
   UMA_HISTOGRAM_ENUMERATION("Platform.IntelMaxMicroArchitecture", arch,
                             base::CPU::MAX_INTEL_MICRO_ARCHITECTURE);
 #endif  // defined(ARCH_CPU_X86_FAMILY)
 }
 
 void RecordDefaultBrowserUMAStat() {
   // Record whether Chrome is the default browser or not.
   ShellIntegration::DefaultWebClientState default_state =
       ShellIntegration::GetDefaultBrowser();
   UMA_HISTOGRAM_ENUMERATION("DefaultBrowser.State", default_state,
                             ShellIntegration::NUM_DEFAULT_STATES);
 }
 
+void RecordLinuxGlibcVersion() {
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+  std::string glibc_version_string(gnu_get_libc_version());
+  std::vector<std::string> split_glibc_version;
+  base::SplitString(glibc_version_string, '.', &split_glibc_version);
+
+  UMALinuxGlibcVersion glibc_version_result = UMA_LINUX_GLIBC_NOT_PARSEABLE;
+  unsigned glibc_major_version = 0;
+  unsigned glibc_minor_version = 0;
+  if (split_glibc_version.size() == 2 &&
+      base::StringToUint(split_glibc_version[0], &glibc_major_version) &&
+      base::StringToUint(split_glibc_version[1], &glibc_minor_version)) {
+    unsigned translated_glibc_minor_version =
+        glibc_minor_version - kGlibcMinorVersionTranslationOffset;
+    if (glibc_major_version == 2 &&

[jar (doing other things), 2013/04/16 03:31:14]

nit: Don't do the translation in lines 86-87 until you verify that you have
version 2.

...and then, since that constant is only used (or applicable) in version 2, just
provide the translation here.  If you want to put it is a translation constant,
move the text down from line 43-45 down here (inside the "if" statement that
verified that we have a major version of 2.

+        (translated_glibc_minor_version >= UMA_LINUX_GLIBC_2_11 &&
+         translated_glibc_minor_version <= UMA_LINUX_GLIBC_2_19)) {
+      glibc_version_result =
+          static_cast<UMALinuxGlibcVersion>(translated_glibc_minor_version);
+    } else {
+      glibc_version_result = UMA_LINUX_GLIBC_UNKNOWN;

[jar (doing other things), 2013/04/16 03:31:14]

nit: I'm betting you made the if statement more complex to get this else clause
in one place... but if you just set it before the if statement (about major
version 2) you'd have it as a fallback.

+    }
+  }
+  UMA_HISTOGRAM_ENUMERATION("Linux.GlibcVersion", glibc_version_result,
+                            UMA_LINUX_GLIBC_VERSION_COUNT);
+#endif
+}
+
 void RecordTouchEventState() {
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   const std::string touch_enabled_switch =
       command_line.HasSwitch(switches::kTouchEvents) ?
       command_line.GetSwitchValueASCII(switches::kTouchEvents) :
       switches::kTouchEventsAuto;
 
   UMATouchEventsState state;
   if (touch_enabled_switch.empty() ||
       touch_enabled_switch == switches::kTouchEventsEnabled) {
@@ skipping 14 matching lines @@
 
 }  // namespace
 
 ChromeBrowserMainExtraPartsMetrics::ChromeBrowserMainExtraPartsMetrics() {
 }
 
 ChromeBrowserMainExtraPartsMetrics::~ChromeBrowserMainExtraPartsMetrics() {
 }
 
 void ChromeBrowserMainExtraPartsMetrics::PreProfileInit() {
-  LogIntelMicroArchitecture();
+  RecordIntelMicroArchitecture();
 }
 
 void ChromeBrowserMainExtraPartsMetrics::PreBrowserStart() {
   about_flags::RecordUMAStatistics(g_browser_process->local_state());
 
   // Querying the default browser state can be slow, do it in the background.
   content::BrowserThread::GetBlockingPool()->PostDelayedTask(
         FROM_HERE,
         base::Bind(&RecordDefaultBrowserUMAStat),
         base::TimeDelta::FromSeconds(45));
 }
 
 void ChromeBrowserMainExtraPartsMetrics::PostBrowserStart() {
+  RecordLinuxGlibcVersion();
   RecordTouchEventState();
 }
 
 namespace chrome {
 
 void AddMetricsExtraParts(ChromeBrowserMainParts* main_parts) {
   main_parts->AddParts(new ChromeBrowserMainExtraPartsMetrics());
 }
 
 }  // namespace chrome