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 = 11,

[jar (doing other things), 2013/04/14 16:14:15]

See note below about how to avoid having to list the enumerated constants values
(i.e., "= 11" etc.) here.

+  UMA_LINUX_GLIBC_2_12 = 12,
+  UMA_LINUX_GLIBC_2_13 = 13,
+  UMA_LINUX_GLIBC_2_14 = 14,
+  UMA_LINUX_GLIBC_2_15 = 15,
+  UMA_LINUX_GLIBC_2_16 = 16,
+  UMA_LINUX_GLIBC_2_17 = 17,
+  UMA_LINUX_GLIBC_2_18 = 18,
+  UMA_LINUX_GLIBC_2_19 = 19,
+  // NOTE: Add new version above this line and update the enum list in
+  // tools/histograms/histograms.xml accordingly.
+  UMA_LINUX_GLIBC_VERSION_COUNT
+};
+
 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)) {
+    if (glibc_major_version == 2 &&
+        (glibc_minor_version >= 11 && glibc_minor_version <= 19)) {
+      // |glibc_minor_version| values lines up with the enum values.
+      glibc_version_result =
+          static_cast<UMALinuxGlibcVersion>(glibc_minor_version);

[jar (doing other things), 2013/04/14 16:14:15]

I think this might read better if you have the adjustment factor:

- 11 + UMA_LINUX_GLIBC_2_11;

Then you don't need mess around and specially define UMA_LINUX_GLIBC_2_11 to
match.... and you'll be set up to deal with another other ranges.  It is
generally nicer not to leave unused spots in the enumeration when going into an
enumerated histogram.

Following in this pattern.... after you verify that you have a major version of
2, you could go ahead and translate it, and then check to see that the
translation is between 
UMA_LINUX_GLIBC_2_11
UMA_LINUX_GLIBC_2_19

I think that will also make the connection with the enums a bit clearer (and
avoid having the less obvious magic constants 11 and 19 show up in code.

WDYT?

+    } else {
+      glibc_version_result = UMA_LINUX_GLIBC_UNKNOWN;
+    }
+  }
+  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