components/browser_watcher/watcher_metrics_provider_win.cc - chromium/src - Git at Google

 // 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 <stddef.h>

 #include <limits>
 #include <vector>

 #include "base/bind.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/process/process.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/registry.h"

 namespace browser_watcher {

 namespace {

 // Process ID APIs on Windows talk in DWORDs, whereas for string formatting
 // and parsing, this code uses int. In practice there are no process IDs with
 // the high bit set on Windows, so there's no danger of overflow if this is
 // done consistently.
 static_assert(sizeof(DWORD) == sizeof(int),
               "process ids are expected to be no larger than int");

 // 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
 // with the given PID is not the same process the data was recorded for.
 // This doesn't matter for the purpose, as eventually the data will be
 // scavenged and reported.
 bool IsDeadProcess(base::StringPiece16 key_or_value_name) {
   // Truncate the input string to the first occurrence of '-', if one exists.
   size_t num_end = key_or_value_name.find(L'-');
   if (num_end != base::StringPiece16::npos)
     key_or_value_name = key_or_value_name.substr(0, num_end);

   // Convert to the numeric PID.
   int pid = 0;
   if (!base::StringToInt(key_or_value_name, &pid) || pid == 0)
     return true;

   // This is a very inexpensive check for the common case of our own PID.
   if (static_cast<base::ProcessId>(pid) == base::GetCurrentProcId())
     return false;

   // The process is not our own - see whether a process with this PID exists.
   // This is more expensive than the above check, but should also be very rare,
   // as this only happens more than once for a given PID if a user is running
   // multiple Chrome instances concurrently.
   base::Process process =
       base::Process::Open(static_cast<base::ProcessId>(pid));
   if (process.IsValid()) {
     // The fact that it was possible to open the process says it's live.
     return false;
   }

   return true;
 }

 void RecordExitCodes(const base::string16& registry_path) {
   base::win::RegKey regkey(HKEY_CURRENT_USER,
                            registry_path.c_str(),
                            KEY_QUERY_VALUE | KEY_SET_VALUE);
   if (!regkey.Valid())
     return;

   size_t num = regkey.GetValueCount();
   if (num == 0)
     return;
   std::vector<base::string16> to_delete;

   // Record the exit codes in a sparse stability histogram, as the range of
   // values used to report failures is large.
   base::HistogramBase* exit_code_histogram =
       base::SparseHistogram::FactoryGet(
           WatcherMetricsProviderWin::kBrowserExitCodeHistogramName,
           base::HistogramBase::kUmaStabilityHistogramFlag);

   for (size_t i = 0; i < num; ++i) {
     base::string16 name;
     if (regkey.GetValueNameAt(static_cast<int>(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 for our own process.
         if (exit_code != STILL_ACTIVE || IsDeadProcess(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());
 }

 void DeleteAllValues(base::win::RegKey* key) {
   DCHECK(key);

   while (key->GetValueCount() != 0) {
     base::string16 value_name;
     LONG res = key->GetValueNameAt(0, &value_name);
     if (res != ERROR_SUCCESS) {
       DVLOG(1) << "Failed to get value name " << res;
       return;
     }

     res = key->DeleteValue(value_name.c_str());
     if (res != ERROR_SUCCESS) {
       DVLOG(1) << "Failed to delete value " << value_name;
       return;
     }
   }
 }

 void DeleteExitFunnels(const base::string16& registry_path) {
   base::win::RegistryKeyIterator it(HKEY_CURRENT_USER, registry_path.c_str());
   if (!it.Valid())
     return;

   // Exit early if no work to do.
   if (it.SubkeyCount() == 0)
     return;

   // Open the key we use for deletion preemptively to prevent reporting
   // multiple times on permission problems.
   base::win::RegKey key(HKEY_CURRENT_USER,
                         registry_path.c_str(),
                         KEY_QUERY_VALUE);
   if (!key.Valid()) {
     DVLOG(1) << "Failed to open " << registry_path << " for writing.";
     return;
   }

   // Key names to delete.
   std::vector<base::string16> keys_to_delete;
   // Constrain the cleanup to 100 exit funnels at a time, as otherwise this may
   // take a long time to finish where a lot of data has accrued. This will be
   // the case in particular for non-UMA users, as the exit funnel data will
   // accrue without bounds for those users.
   const size_t kMaxCleanup = 100;
   for (; it.Valid() && keys_to_delete.size() < kMaxCleanup; ++it) {
     base::win::RegKey sub_key;
     LONG res =
         sub_key.Open(key.Handle(), it.Name(), KEY_QUERY_VALUE | KEY_SET_VALUE);
     if (res != ERROR_SUCCESS) {
       DVLOG(1) << "Failed to open subkey " << it.Name();
       return;
     }
     DeleteAllValues(&sub_key);

     // Schedule the subkey for deletion.
     keys_to_delete.push_back(it.Name());
   }

   for (const base::string16& key_name : keys_to_delete) {
     LONG res = key.DeleteEmptyKey(key_name.c_str());
     if (res != ERROR_SUCCESS)
       DVLOG(1) << "Failed to delete key " << key_name;
   }
 }

 // Called from the blocking pool when metrics reporting is disabled, as there
 // may be a sizable stash of data to delete.
 void DeleteExitCodeRegistryKey(const base::string16& registry_path) {
   CHECK_NE(L"", registry_path);

   DeleteExitFunnels(registry_path);

   base::win::RegKey key;
   LONG res = key.Open(HKEY_CURRENT_USER, registry_path.c_str(),
                       KEY_QUERY_VALUE | KEY_SET_VALUE);
   if (res == ERROR_SUCCESS) {
     DeleteAllValues(&key);
     res = key.DeleteEmptyKey(L"");
   }
   if (res != ERROR_FILE_NOT_FOUND && res != ERROR_SUCCESS)
     DVLOG(1) << "Failed to delete exit code key " << registry_path;
 }

 }  // namespace

 const char WatcherMetricsProviderWin::kBrowserExitCodeHistogramName[] =
     "Stability.BrowserExitCodes";

 WatcherMetricsProviderWin::WatcherMetricsProviderWin(
     const base::string16& registry_path,
     base::TaskRunner* cleanup_io_task_runner)
     : recording_enabled_(false),
       cleanup_scheduled_(false),
       registry_path_(registry_path),
       cleanup_io_task_runner_(cleanup_io_task_runner) {
   DCHECK(cleanup_io_task_runner_);
 }

 WatcherMetricsProviderWin::~WatcherMetricsProviderWin() {
 }

 void WatcherMetricsProviderWin::OnRecordingEnabled() {
   recording_enabled_ = true;
 }

 void WatcherMetricsProviderWin::OnRecordingDisabled() {
   if (!recording_enabled_ && !cleanup_scheduled_) {
     // When metrics reporting is disabled, the providers get an
     // OnRecordingDisabled notification at startup. Use that first notification
     // to issue the cleanup task.
     cleanup_io_task_runner_->PostTask(
         FROM_HERE, base::Bind(&DeleteExitCodeRegistryKey, registry_path_));

     cleanup_scheduled_ = true;
   }
 }

 void WatcherMetricsProviderWin::ProvideStabilityMetrics(
     metrics::SystemProfileProto* /* system_profile_proto */) {
   // Note that if there are multiple instances of Chrome running in the same
   // user account, there's a small race that will double-report the exit codes
   // from both/multiple instances. This ought to be vanishingly rare and will
   // only manifest as low-level "random" noise. To work around this it would be
   // necessary to implement some form of global locking, which is not worth it
   // here.
   RecordExitCodes(registry_path_);
   DeleteExitFunnels(registry_path_);
 }

 }  // namespace browser_watcher
	// 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 <stddef.h>

	#include <limits>
	#include <vector>

	#include "base/bind.h"
	#include "base/metrics/sparse_histogram.h"
	#include "base/process/process.h"
	#include "base/strings/string_number_conversions.h"
	#include "base/strings/string_piece.h"
	#include "base/strings/utf_string_conversions.h"
	#include "base/win/registry.h"

	namespace browser_watcher {

	namespace {

	// Process ID APIs on Windows talk in DWORDs, whereas for string formatting
	// and parsing, this code uses int. In practice there are no process IDs with
	// the high bit set on Windows, so there's no danger of overflow if this is
	// done consistently.
	static_assert(sizeof(DWORD) == sizeof(int),
	"process ids are expected to be no larger than int");

	// 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
	// with the given PID is not the same process the data was recorded for.
	// This doesn't matter for the purpose, as eventually the data will be
	// scavenged and reported.
	bool IsDeadProcess(base::StringPiece16 key_or_value_name) {
	// Truncate the input string to the first occurrence of '-', if one exists.
	size_t num_end = key_or_value_name.find(L'-');
	if (num_end != base::StringPiece16::npos)
	key_or_value_name = key_or_value_name.substr(0, num_end);

	// Convert to the numeric PID.
	int pid = 0;
	if (!base::StringToInt(key_or_value_name, &pid) \|\| pid == 0)
	return true;

	// This is a very inexpensive check for the common case of our own PID.
	if (static_cast<base::ProcessId>(pid) == base::GetCurrentProcId())
	return false;

	// The process is not our own - see whether a process with this PID exists.
	// This is more expensive than the above check, but should also be very rare,
	// as this only happens more than once for a given PID if a user is running
	// multiple Chrome instances concurrently.
	base::Process process =
	base::Process::Open(static_cast<base::ProcessId>(pid));
	if (process.IsValid()) {
	// The fact that it was possible to open the process says it's live.
	return false;
	}

	return true;
	}

	void RecordExitCodes(const base::string16& registry_path) {
	base::win::RegKey regkey(HKEY_CURRENT_USER,
	registry_path.c_str(),
	KEY_QUERY_VALUE \| KEY_SET_VALUE);
	if (!regkey.Valid())
	return;

	size_t num = regkey.GetValueCount();
	if (num == 0)
	return;
	std::vector<base::string16> to_delete;

	// Record the exit codes in a sparse stability histogram, as the range of
	// values used to report failures is large.
	base::HistogramBase* exit_code_histogram =
	base::SparseHistogram::FactoryGet(
	WatcherMetricsProviderWin::kBrowserExitCodeHistogramName,
	base::HistogramBase::kUmaStabilityHistogramFlag);

	for (size_t i = 0; i < num; ++i) {
	base::string16 name;
	if (regkey.GetValueNameAt(static_cast<int>(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 for our own process.
	if (exit_code != STILL_ACTIVE \|\| IsDeadProcess(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());
	}

	void DeleteAllValues(base::win::RegKey* key) {
	DCHECK(key);

	while (key->GetValueCount() != 0) {
	base::string16 value_name;
	LONG res = key->GetValueNameAt(0, &value_name);
	if (res != ERROR_SUCCESS) {
	DVLOG(1) << "Failed to get value name " << res;
	return;
	}

	res = key->DeleteValue(value_name.c_str());
	if (res != ERROR_SUCCESS) {
	DVLOG(1) << "Failed to delete value " << value_name;
	return;
	}
	}
	}

	void DeleteExitFunnels(const base::string16& registry_path) {
	base::win::RegistryKeyIterator it(HKEY_CURRENT_USER, registry_path.c_str());
	if (!it.Valid())
	return;

	// Exit early if no work to do.
	if (it.SubkeyCount() == 0)
	return;

	// Open the key we use for deletion preemptively to prevent reporting
	// multiple times on permission problems.
	base::win::RegKey key(HKEY_CURRENT_USER,
	registry_path.c_str(),
	KEY_QUERY_VALUE);
	if (!key.Valid()) {
	DVLOG(1) << "Failed to open " << registry_path << " for writing.";
	return;
	}

	// Key names to delete.
	std::vector<base::string16> keys_to_delete;
	// Constrain the cleanup to 100 exit funnels at a time, as otherwise this may
	// take a long time to finish where a lot of data has accrued. This will be
	// the case in particular for non-UMA users, as the exit funnel data will
	// accrue without bounds for those users.
	const size_t kMaxCleanup = 100;
	for (; it.Valid() && keys_to_delete.size() < kMaxCleanup; ++it) {
	base::win::RegKey sub_key;
	LONG res =
	sub_key.Open(key.Handle(), it.Name(), KEY_QUERY_VALUE \| KEY_SET_VALUE);
	if (res != ERROR_SUCCESS) {
	DVLOG(1) << "Failed to open subkey " << it.Name();
	return;
	}
	DeleteAllValues(&sub_key);

	// Schedule the subkey for deletion.
	keys_to_delete.push_back(it.Name());
	}

	for (const base::string16& key_name : keys_to_delete) {
	LONG res = key.DeleteEmptyKey(key_name.c_str());
	if (res != ERROR_SUCCESS)
	DVLOG(1) << "Failed to delete key " << key_name;
	}
	}

	// Called from the blocking pool when metrics reporting is disabled, as there
	// may be a sizable stash of data to delete.
	void DeleteExitCodeRegistryKey(const base::string16& registry_path) {
	CHECK_NE(L"", registry_path);

	DeleteExitFunnels(registry_path);

	base::win::RegKey key;
	LONG res = key.Open(HKEY_CURRENT_USER, registry_path.c_str(),
	KEY_QUERY_VALUE \| KEY_SET_VALUE);
	if (res == ERROR_SUCCESS) {
	DeleteAllValues(&key);
	res = key.DeleteEmptyKey(L"");
	}
	if (res != ERROR_FILE_NOT_FOUND && res != ERROR_SUCCESS)
	DVLOG(1) << "Failed to delete exit code key " << registry_path;
	}

	} // namespace

	const char WatcherMetricsProviderWin::kBrowserExitCodeHistogramName[] =
	"Stability.BrowserExitCodes";

	WatcherMetricsProviderWin::WatcherMetricsProviderWin(
	const base::string16& registry_path,
	base::TaskRunner* cleanup_io_task_runner)
	: recording_enabled_(false),
	cleanup_scheduled_(false),
	registry_path_(registry_path),
	cleanup_io_task_runner_(cleanup_io_task_runner) {
	DCHECK(cleanup_io_task_runner_);
	}

	WatcherMetricsProviderWin::~WatcherMetricsProviderWin() {
	}

	void WatcherMetricsProviderWin::OnRecordingEnabled() {
	recording_enabled_ = true;
	}

	void WatcherMetricsProviderWin::OnRecordingDisabled() {
	if (!recording_enabled_ && !cleanup_scheduled_) {
	// When metrics reporting is disabled, the providers get an
	// OnRecordingDisabled notification at startup. Use that first notification
	// to issue the cleanup task.
	cleanup_io_task_runner_->PostTask(
	FROM_HERE, base::Bind(&DeleteExitCodeRegistryKey, registry_path_));

	cleanup_scheduled_ = true;
	}
	}

	void WatcherMetricsProviderWin::ProvideStabilityMetrics(
	metrics::SystemProfileProto* /* system_profile_proto */) {
	// Note that if there are multiple instances of Chrome running in the same
	// user account, there's a small race that will double-report the exit codes
	// from both/multiple instances. This ought to be vanishingly rare and will
	// only manifest as low-level "random" noise. To work around this it would be
	// necessary to implement some form of global locking, which is not worth it
	// here.
	RecordExitCodes(registry_path_);
	DeleteExitFunnels(registry_path_);
	}

	} // namespace browser_watcher