Browser watcher end-end-to-end .

components/browser_watcher/watcher_metrics_provider_win.cc

+// Copyright (c) 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 "components/browser_watcher/watcher_metrics_provider_win.h"
+
+#include "base/metrics/sparse_histogram.h"
+#include "base/process/process_handle.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/win/registry.h"
+
+namespace browser_watcher {
+
+namespace {
+
+// This function does soft matching on the PID recorded in the key only.
+// Due to PID reuse, the possibility exists that the process that's now live
+// is not the same process the data was recorded for. This doesn't matter for
+// this purpose, as eventually the data will be scavenged and reported.
+bool IsLiveProcess(const base::string16& key_name) {
+  int pid = 0;
+  base::StringToInt(key_name, &pid);
+
+  if (pid == 0)
+    return false;
+
+  // This is a very inexpensive check for the common case of our own PID.
+  if (static_cast<base::ProcessId>(pid) == base::GetCurrentProcId())
+    return true;
+
+  // The process is not our own - see whether a process with this PID exists.
+  base::ProcessHandle process = base::kNullProcessHandle;
+  if (base::OpenProcessHandle(static_cast<base::ProcessId>(pid), &process)) {
+    base::CloseProcessHandle(process);
+
+    return true;
+  }
+
+  return false;
+}
+
+}  // namespace
+
+const char WatcherMetricsProviderWin::kBrowserExitCodeHistogramName[] =
+    "Stability.BrowserExitCodes";
+
+
+WatcherMetricsProviderWin::WatcherMetricsProviderWin(
+    const base::char16* registry_path) : registry_path_(registry_path) {
+}
+
+WatcherMetricsProviderWin::~WatcherMetricsProviderWin() {
+}
+
+void WatcherMetricsProviderWin::ProvideStabilityMetrics(
+    metrics::SystemProfileProto* system_profile_proto) {
+  base::win::RegKey regkey(HKEY_CURRENT_USER,
+                           registry_path_.c_str(),
+                           KEY_QUERY_VALUE | KEY_SET_VALUE);
+
+  std::vector<base::string16> to_delete;
+  size_t num = regkey.GetValueCount();
+
+  // Record the exit codes in a sparse histogram, as the range of values
+  // used to report failures is large.
+  base::HistogramBase* exit_code_histogram =
+      // TODO(siggi): is this an acceptable name?
+      base::SparseHistogram::FactoryGet(kBrowserExitCodeHistogramName,
+          base::HistogramBase::kUmaStabilityHistogramFlag);
+
+  for (size_t i = 0; i < num; ++i) {
+    base::string16 name;
+    if (regkey.GetValueNameAt(i, &name) == ERROR_SUCCESS) {
+      DWORD exit_code = 0;
+      if (regkey.ReadValueDW(name.c_str(), &exit_code) == ERROR_SUCCESS) {
+        // Do not report exit codes for processes that are still live, notably
+        // not for our own process.
+        if (exit_code != STILL_ACTIVE || !IsLiveProcess(name)) {
+          to_delete.push_back(name);
+          exit_code_histogram->Add(exit_code);
+        }
+      }
+    }
+  }
+
+  // Delete the values reported above.
+  for (size_t i = 0; i < to_delete.size(); ++i)
+    regkey.DeleteValue(to_delete[i].c_str());
+}
+
+}  // namespace browser_watcher