Improving the process model extension API

chrome/browser/extensions/extension_processes_api.cc

 // Copyright (c) 2012 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/extensions/extension_processes_api.h"
 
 #include "base/callback.h"
 #include "base/json/json_writer.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 
 #include "chrome/browser/extensions/extension_event_router.h"
 #include "chrome/browser/extensions/extension_processes_api_constants.h"
+#include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/extensions/extension_tabs_module_constants.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/task_manager/task_manager.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
+#include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/extensions/extension_error_utils.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/notification_details.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_source.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/render_view_host_delegate.h"
+#include "content/public/browser/render_widget_host.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/common/result_codes.h"
 
 namespace keys = extension_processes_api_constants;
-
-DictionaryValue* CreateProcessValue(int process_id,
-                                    const std::string& type,
-                                    double cpu,
-                                    int64 net,
-                                    int64 pr_mem,
-                                    int64 sh_mem) {
+namespace errors = extension_processes_api_constants;
+
+namespace {
+
+#if defined(ENABLE_TASK_MANAGER)
+
+DictionaryValue* CreateCacheData(
+    const WebKit::WebCache::ResourceTypeStat& stat) {
+
+  DictionaryValue* cache = new DictionaryValue();
+  cache->SetDouble(keys::kCacheSize, static_cast<double>(stat.size));
+  cache->SetDouble(keys::kCacheLiveSize, static_cast<double>(stat.liveSize));
+  return cache;
+}
+
+void SetProcessType(DictionaryValue* result,
+                    TaskManagerModel* model,
+                    int index) {
+  // Determine process type

[Matt Perry, 2012/05/07 20:33:34]

nit: end with .

[nasko, 2012/05/08 00:34:56]

Done.

+  std::string type = keys::kProcessTypeOther;
+  TaskManager::Resource::Type resource_type = model->GetResourceType(index);
+  switch (resource_type) {
+    case TaskManager::Resource::BROWSER:
+      type = keys::kProcessTypeBrowser;
+      break;
+    case TaskManager::Resource::RENDERER:
+      type = keys::kProcessTypeRenderer;
+      break;
+    case TaskManager::Resource::EXTENSION:
+      type = keys::kProcessTypeExtension;
+      break;
+    case TaskManager::Resource::NOTIFICATION:
+      type = keys::kProcessTypeNotification;
+      break;
+    case TaskManager::Resource::PLUGIN:
+      type = keys::kProcessTypePlugin;
+      break;
+    case TaskManager::Resource::WORKER:
+      type = keys::kProcessTypeWorker;
+      break;
+    case TaskManager::Resource::NACL:
+      type = keys::kProcessTypeNacl;
+      break;
+    case TaskManager::Resource::UTILITY:
+      type = keys::kProcessTypeUtility;
+      break;
+    case TaskManager::Resource::GPU:
+      type = keys::kProcessTypeGPU;
+      break;
+    case TaskManager::Resource::PROFILE_IMPORT:
+    case TaskManager::Resource::ZYGOTE:
+    case TaskManager::Resource::SANDBOX_HELPER:
+    case TaskManager::Resource::UNKNOWN:
+      type = keys::kProcessTypeOther;
+      break;
+    default:
+      NOTREACHED() << "Unknown resource type.";
+  }
+  result->SetString(keys::kTypeKey, type);
+}
+
+ListValue* GetTabsForProcess(int process_id) {
+  ListValue* tabs_list = new ListValue();
+
+  // The tabs list only makes sense for render processes, so if we don't find
+  // one, just return the empty list.
+  content::RenderProcessHost* rph =
+      content::RenderProcessHost::FromID(process_id);
+  if (rph == NULL)
+    return tabs_list;
+
+  int tab_id = -1;
+  // We need to loop through all the RVHs to ensure we collect the set of all
+  // tabs using this renderer process.
+  content::RenderProcessHost::RenderWidgetHostsIterator iter(
+      rph->GetRenderWidgetHostsIterator());
+  for (; !iter.IsAtEnd(); iter.Advance()) {
+    const content::RenderWidgetHost* widget = iter.GetCurrentValue();
+    DCHECK(widget);
+    if (!widget || !widget->IsRenderView())
+      continue;
+
+    content::RenderViewHost* host = content::RenderViewHost::From(
+        const_cast<content::RenderWidgetHost*>(widget));
+    content::RenderViewHostDelegate* host_delegate = host->GetDelegate();
+    content::WebContents* contents = host_delegate->GetAsWebContents();
+    if (contents != NULL) {
+      tab_id = ExtensionTabUtil::GetTabId(contents);
+      if (tab_id != -1)
+        tabs_list->Append(Value::CreateIntegerValue(tab_id));
+    }
+  }
+
+  return tabs_list;
+}
+
+// This function creates a Process object to be returned to the extensions
+// using these APIs. For memory details, which are not added by this function,
+// the callers need to use AddMemoryDetails.
+DictionaryValue* CreateProcessFromModel(int process_id,
+                                        TaskManagerModel* model,
+                                        int index,
+                                        bool include_optional) {
   DictionaryValue* result = new DictionaryValue();
+  size_t mem;
+
   result->SetInteger(keys::kIdKey, process_id);
-  result->SetString(keys::kTypeKey, type);
-  result->SetDouble(keys::kCpuKey, cpu);
+  result->SetInteger(keys::kOsProcessIdKey, model->GetProcessId(index));
+  SetProcessType(result, model, index);
+  result->SetString(keys::kProfileKey,
+      model->GetResourceProfileName(index));
+
+  result->Set(keys::kTabsListKey, GetTabsForProcess(process_id));
+
+  // If we don't need to include the optional properties, just return now.
+  if (!include_optional)
+    return result;
+
+  result->SetDouble(keys::kCpuKey, model->GetCPUUsage(index));
+
+  if (model->GetV8Memory(index, &mem))
+    result->SetDouble(keys::kJsMemoryAllocatedKey,
+        static_cast<double>(mem));
+
+  if (model->GetV8MemoryUsed(index, &mem))
+    result->SetDouble(keys::kJsMemoryUsedKey,
+        static_cast<double>(mem));
+
+  if (model->GetSqliteMemoryUsedBytes(index, &mem))
+    result->SetDouble(keys::kSqliteMemoryKey,
+        static_cast<double>(mem));
+
+  WebKit::WebCache::ResourceTypeStats cache_stats;
+  if (model->GetWebCoreCacheStats(index, &cache_stats)) {
+    result->Set(keys::kImageCacheKey,
+                CreateCacheData(cache_stats.images));
+    result->Set(keys::kScriptCacheKey,
+                CreateCacheData(cache_stats.scripts));
+    result->Set(keys::kCssCacheKey,
+                CreateCacheData(cache_stats.cssStyleSheets));
+  }
+
+  // Network and FPS are reported by the TaskManager per resource (tab), not
+  // per process, therefore we need to iterate through the group of resources
+  // and aggregate the data.
+  float fps = 0, tmp = 0;
+  int64 net = 0;
+  int length = model->GetGroupRangeForResource(index).second;
+  for (int i = 0; i < length; ++i) {
+    net += model->GetNetworkUsage(index + i);
+    if (model->GetFPS(index + i, &tmp))
+      fps += tmp;
+  }
+  result->SetDouble(keys::kFPSKey, static_cast<double>(fps));
   result->SetDouble(keys::kNetworkKey, static_cast<double>(net));
+
+  return result;
+}
+
+// Since memory details are expensive to gather, we don't do it by default.
+// This function is a helper to add memory details data to an existing
+// Process object representation.
+void AddMemoryDetails(DictionaryValue* result,
+                      TaskManagerModel* model,
+                      int index) {
+  size_t mem;
+  int64 pr_mem = model->GetPrivateMemory(index, &mem) ?
+      static_cast<int64>(mem) : -1;
   result->SetDouble(keys::kPrivateMemoryKey, static_cast<double>(pr_mem));
-  result->SetDouble(keys::kSharedMemoryKey, static_cast<double>(sh_mem));
-  return result;
-}
+}
+
+#endif  // defined(ENABLE_TASK_MANAGER)
+
+} // local namespace
 
 ExtensionProcessesEventRouter* ExtensionProcessesEventRouter::GetInstance() {
   return Singleton<ExtensionProcessesEventRouter>::get();
 }
 
-ExtensionProcessesEventRouter::ExtensionProcessesEventRouter() {
+ExtensionProcessesEventRouter::ExtensionProcessesEventRouter()
+    : listeners_(0),
+      task_manager_listening_(false) {
 #if defined(ENABLE_TASK_MANAGER)
   model_ = TaskManager::GetInstance()->model();
   model_->AddObserver(this);
+
+  registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_HANG,
+      content::NotificationService::AllSources());
+  registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
+      content::NotificationService::AllSources());
 #endif  // defined(ENABLE_TASK_MANAGER)
 }
 
 ExtensionProcessesEventRouter::~ExtensionProcessesEventRouter() {
 #if defined(ENABLE_TASK_MANAGER)
+  registrar_.Remove(this, content::NOTIFICATION_RENDERER_PROCESS_HANG,
+      content::NotificationService::AllSources());
+  registrar_.Remove(this, content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
+      content::NotificationService::AllSources());
+
+  if (task_manager_listening_)
+    model_->StopListening();
+
   model_->RemoveObserver(this);
 #endif  // defined(ENABLE_TASK_MANAGER)
 }
 
 void ExtensionProcessesEventRouter::ObserveProfile(Profile* profile) {
   profiles_.insert(profile);
 }
 
 void ExtensionProcessesEventRouter::ListenerAdded() {
 #if defined(ENABLE_TASK_MANAGER)
+  // The task manager has its own ref count to balance other callers of
+  // StartUpdating/StopUpdating.
   model_->StartUpdating();
 #endif  // defined(ENABLE_TASK_MANAGER)
+  ++listeners_;
 }
 
 void ExtensionProcessesEventRouter::ListenerRemoved() {
-#if defined(ENABLE_TASK_MANAGER)
+  DCHECK(listeners_ > 0);
+  --listeners_;
+#if defined(ENABLE_TASK_MANAGER)
+  // The task manager has its own ref count to balance other callers of
+  // StartUpdating/StopUpdating.
   model_->StopUpdating();
 #endif  // defined(ENABLE_TASK_MANAGER)
 }
 
+bool ExtensionProcessesEventRouter::DidStartTaskManagerListening() {

[Matt Perry, 2012/05/07 20:33:34]

DidFoo sounds like you're notifying someone that Foo just happened. You should
just drop the "Did".

[nasko, 2012/05/08 00:34:56]

Done.

+#if defined(ENABLE_TASK_MANAGER)
+  if (!task_manager_listening_) {
+    model_->StartListening();
+    task_manager_listening_ = true;
+    return true;
+  }
+#endif  // defined(ENABLE_TASK_MANAGER)
+  return false;
+}
+
+void ExtensionProcessesEventRouter::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+
+  switch (type) {
+    case content::NOTIFICATION_RENDERER_PROCESS_HANG:
+      ProcessHangEvent(
+          content::Source<content::RenderWidgetHost>(source).ptr());
+      break;
+    case content::NOTIFICATION_RENDERER_PROCESS_CLOSED:
+      ProcessClosedEvent(
+          content::Source<content::RenderProcessHost>(source).ptr(),
+          content::Details<content::RenderProcessHost::RendererClosedDetails>(
+              details).ptr());
+      break;
+    default:
+      NOTREACHED() << "Unexpected observe of type " << type;
+  }
+  return;
+}
+
+void ExtensionProcessesEventRouter::OnItemsAdded(int start, int length) {
+#if defined(ENABLE_TASK_MANAGER)
+  DCHECK_EQ(length, 1);
+  int index = start;
+
+  std::string event(keys::kOnCreated);
+  if (!HasEventListeners(event))
+    return;
+
+  // If the item being added is not the first one in the group, find the base
+  // index and use it for retrieving the process data.
+  if (!model_->IsResourceFirstInGroup(start)) {
+    index = model_->GetGroupIndexForResource(start);
+  }
+
+  ListValue args;
+  DictionaryValue* process = CreateProcessFromModel(
+      model_->GetUniqueChildProcessId(index), model_, index, false);
+  DCHECK(process != NULL);
+
+  if (process == NULL)
+    return;
+
+  args.Append(process);
+
+  std::string json_args;
+  base::JSONWriter::Write(&args, &json_args);
+  NotifyProfiles(keys::kOnCreated, json_args);
+#endif  // defined(ENABLE_TASK_MANAGER)
+}
+
 void ExtensionProcessesEventRouter::OnItemsChanged(int start, int length) {
 #if defined(ENABLE_TASK_MANAGER)
-  if (model_) {
+  // If we don't have any listeners, return immediately.
+  if (listeners_ == 0)
+    return;
+
+  if (!model_)
+    return;
+
+  // We need to know which type of onUpdated events to fire and whether to
+  // collect memory or not.
+  std::string updated_event(keys::kOnUpdated);
+  std::string updated_event_memory(keys::kOnUpdatedWithMemory);
+  bool updated = HasEventListeners(updated_event);
+  bool updated_memory = HasEventListeners(updated_event_memory);
+
+  DCHECK(updated || updated_memory);
+
+  IDMap<DictionaryValue> processes_map;
+  for (int i = start; i < start + length; i++) {
+    if (model_->IsResourceFirstInGroup(i)) {
+      int id = model_->GetUniqueChildProcessId(i);
+      DictionaryValue* process = CreateProcessFromModel(id, model_, i, true);
+      processes_map.AddWithID(process, i);
+    }
+  }
+
+  int id;
+  std::string idkey(keys::kIdKey);
+  DictionaryValue* processes = new DictionaryValue();
+
+  if (updated) {
+    IDMap<DictionaryValue>::iterator it(&processes_map);
+    for (; !it.IsAtEnd(); it.Advance()) {
+      if (!it.GetCurrentValue()->GetInteger(idkey, &id))
+        continue;
+
+      // Store each process indexed by the string version of its id.
+      processes->Set(base::IntToString(id), it.GetCurrentValue());
+    }
+
     ListValue args;
-    DictionaryValue* processes = new DictionaryValue();
-    for (int i = start; i < start + length; i++) {
-      if (model_->IsResourceFirstInGroup(i)) {
-        int id = model_->GetProcessId(i);
-
-        // Determine process type
-        std::string type = keys::kProcessTypeOther;
-        TaskManager::Resource::Type resource_type = model_->GetResourceType(i);
-        switch (resource_type) {
-          case TaskManager::Resource::BROWSER:
-            type = keys::kProcessTypeBrowser;
-            break;
-          case TaskManager::Resource::RENDERER:
-            type = keys::kProcessTypeRenderer;
-            break;
-          case TaskManager::Resource::EXTENSION:
-            type = keys::kProcessTypeExtension;
-            break;
-          case TaskManager::Resource::NOTIFICATION:
-            type = keys::kProcessTypeNotification;
-            break;
-          case TaskManager::Resource::PLUGIN:
-            type = keys::kProcessTypePlugin;
-            break;
-          case TaskManager::Resource::WORKER:
-            type = keys::kProcessTypeWorker;
-            break;
-          case TaskManager::Resource::NACL:
-            type = keys::kProcessTypeNacl;
-            break;
-          case TaskManager::Resource::UTILITY:
-            type = keys::kProcessTypeUtility;
-            break;
-          case TaskManager::Resource::GPU:
-            type = keys::kProcessTypeGPU;
-            break;
-          case TaskManager::Resource::PROFILE_IMPORT:
-          case TaskManager::Resource::ZYGOTE:
-          case TaskManager::Resource::SANDBOX_HELPER:
-          case TaskManager::Resource::UNKNOWN:
-            type = keys::kProcessTypeOther;
-            break;
-          default:
-            NOTREACHED() << "Unknown resource type.";
-        }
-
-        // Get process metrics as numbers
-        double cpu = model_->GetCPUUsage(i);
-
-        // TODO(creis): Network is actually reported per-resource (tab),
-        // not per-process.  We should aggregate it here.
-        int64 net = model_->GetNetworkUsage(i);
-        size_t mem;
-        int64 pr_mem = model_->GetPrivateMemory(i, &mem) ?
-            static_cast<int64>(mem) : -1;
-        int64 sh_mem = model_->GetSharedMemory(i, &mem) ?
-            static_cast<int64>(mem) : -1;
-
-        // Store each process indexed by the string version of its id
-        processes->Set(base::IntToString(id),
-                       CreateProcessValue(id, type, cpu, net, pr_mem, sh_mem));
-      }
-    }
     args.Append(processes);
-
     std::string json_args;
     base::JSONWriter::Write(&args, &json_args);
-
-    // Notify each profile that is interested.
-    for (ProfileSet::iterator it = profiles_.begin();
-         it != profiles_.end(); it++) {
-      Profile* profile = *it;
-      DispatchEvent(profile, keys::kOnUpdated, json_args);
-    }
-  }
-#endif  // defined(ENABLE_TASK_MANAGER)
-}
-
-void ExtensionProcessesEventRouter::DispatchEvent(Profile* profile,
+    NotifyProfiles(keys::kOnUpdated, json_args);
+  }
+
+  if (updated_memory) {
+    IDMap<DictionaryValue>::iterator it(&processes_map);
+    for (; !it.IsAtEnd(); it.Advance()) {
+      if (!it.GetCurrentValue()->GetInteger(idkey, &id))
+        continue;
+
+      AddMemoryDetails(it.GetCurrentValue(), model_, it.GetCurrentKey());
+
+      // Store each process indexed by the string version of its id if we didn't
+      // already insert it as part of the onUpdated processing above.
+      if (!updated)
+        processes->Set(base::IntToString(id), it.GetCurrentValue());
+    }
+
+    ListValue args;
+    args.Append(processes);
+    std::string json_args;
+    base::JSONWriter::Write(&args, &json_args);
+    NotifyProfiles(keys::kOnUpdatedWithMemory, json_args);
+  }
+#endif  // defined(ENABLE_TASK_MANAGER)
+}
+
+void ExtensionProcessesEventRouter::OnItemsToBeRemoved(int start, int length) {
+#if defined(ENABLE_TASK_MANAGER)
+  DCHECK(length == 1);
+
+  // Process exit for renderer processes has the data about exit code and
+  // termination status, therefore we will rely on notifications and not on
+  // the Task Manager data. We do use the rest of this method for non-renderer
+  // processes.
+  if (model_->GetResourceType(start) == TaskManager::Resource::RENDERER)
+    return;
+
+  // The callback function parameters.
+  ListValue args;
+
+  // First arg: The id of the process that was closed.
+  args.Append(Value::CreateIntegerValue(
+      model_->GetUniqueChildProcessId(start)));
+
+  // Second arg: The exit type for the process.
+  args.Append(Value::CreateIntegerValue(0));
+
+  // Third arg: The exit code for the process.
+  args.Append(Value::CreateIntegerValue(0));
+
+  std::string json_args;
+  base::JSONWriter::Write(&args, &json_args);
+  NotifyProfiles(keys::kOnExited, json_args);
+#endif  // defined(ENABLE_TASK_MANAGER)
+}
+
+void ExtensionProcessesEventRouter::ProcessHangEvent(
+    content::RenderWidgetHost* widget) {
+#if defined(ENABLE_TASK_MANAGER)
+  std::string event(keys::kOnUnresponsive);
+  if (!HasEventListeners(event))
+    return;
+
+  DictionaryValue* process = NULL;
+  int count = model_->ResourceCount();
+  int id = widget->GetProcess()->GetID();
+
+  for (int i = 0; i < count; ++i) {
+    if (model_->IsResourceFirstInGroup(i)) {
+      if (id == model_->GetUniqueChildProcessId(i)) {
+        process = CreateProcessFromModel(id, model_, i, false);
+        break;
+      }
+    }
+  }
+
+  DCHECK(process);
+  if (process == NULL)
+    return;
+
+  ListValue args;
+  args.Append(process);
+
+  std::string json_args;
+  base::JSONWriter::Write(&args, &json_args);
+  NotifyProfiles(keys::kOnUnresponsive, json_args);
+#endif  // defined(ENABLE_TASK_MANAGER)
+}
+
+void ExtensionProcessesEventRouter::ProcessClosedEvent(
+    content::RenderProcessHost* rph,
+    content::RenderProcessHost::RendererClosedDetails* details) {
+#if defined(ENABLE_TASK_MANAGER)
+  // The callback function parameters.
+  ListValue args;
+
+  // First arg: The id of the process that was closed.
+  args.Append(Value::CreateIntegerValue(rph->GetID()));
+
+  // Second arg: The exit type for the process.
+  args.Append(Value::CreateIntegerValue(details->status));
+
+  // Third arg: The exit code for the process.
+  args.Append(Value::CreateIntegerValue(details->exit_code));
+
+  std::string json_args;
+  base::JSONWriter::Write(&args, &json_args);
+  NotifyProfiles(keys::kOnExited, json_args);
+#endif  // defined(ENABLE_TASK_MANAGER)
+}
+
+void ExtensionProcessesEventRouter::DispatchEvent(
+    Profile* profile,
     const char* event_name,
     const std::string& json_args) {
   if (profile && profile->GetExtensionEventRouter()) {
     profile->GetExtensionEventRouter()->DispatchEventToRenderers(
         event_name, json_args, NULL, GURL());
   }
 }
 
+void ExtensionProcessesEventRouter::NotifyProfiles(const char* event_name,
+                                                   std::string json_args) {
+  for (ProfileSet::iterator it = profiles_.begin();
+       it != profiles_.end(); it++) {
+    Profile* profile = *it;
+    DispatchEvent(profile, event_name, json_args);
+  }
+}
+
+// In order to determine whether there are any listeners for the event of
+// interest, we need to ask each profile whether it has one registered.
+// We only need to look for the profiles that have registered with the
+// this extension API.
+bool ExtensionProcessesEventRouter::HasEventListeners(std::string& event_name) {
+  for (ProfileSet::iterator it = profiles_.begin();
+       it != profiles_.end(); it++) {
+    Profile* profile = *it;
+    ExtensionEventRouter* router = profile->GetExtensionEventRouter();
+    if (!router)
+      continue;
+
+    if (router->HasEventListener(event_name))
+      return true;
+  }
+  return false;
+}
+
 bool GetProcessIdForTabFunction::RunImpl() {
-  int tab_id;
-  EXTENSION_FUNCTION_VALIDATE(args_->GetInteger(0, &tab_id));
-
+#if defined(ENABLE_TASK_MANAGER)
+  EXTENSION_FUNCTION_VALIDATE(args_->GetInteger(0, &tab_id_));
+
+  // Add a reference, which is balanced in GetProcessIdForTab to keep the object
+  // around and allow for the callback to be invoked.
+  AddRef();
+
+  // If the task manager is already listening, just post a task to execute
+  // which will invoke the callback once we have returned from this function.
+  // Otherwise, wait for the notification that the task manager is done with
+  // the data gathering.
+  if (ExtensionProcessesEventRouter::GetInstance()->
+          is_task_manager_listening()) {
+    MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
+        &GetProcessIdForTabFunction::GetProcessIdForTab, this));
+  } else {
+    registrar_.Add(this,
+                   chrome::NOTIFICATION_TASK_MANAGER_CHILD_PROCESSES_DATA_READY,
+                   content::NotificationService::AllSources());
+    ExtensionProcessesEventRouter::GetInstance()->
+        DidStartTaskManagerListening();

[Matt Perry, 2012/05/07 20:33:34]

If this returns false, the AddRef will never be balanced.

[nasko, 2012/05/08 00:34:56]

Removed the return value of StartTaskManagerListening, as it is no longer used
(it was in a previous revision). Does address your concern?

[Matt Perry, 2012/05/08 01:00:34]

Actually I was more worried about what would happen if ENABLE_TASK_MANAGER were
not defined, but I guess the function wouldn't get called in that case.

+  }
+
+  return true;
+#else
+  error_ = ExtensionErrorUtils::FormatErrorMessage(
+      errors::kExtensionNotSupported);
+  return false;
+#endif  // defined(ENABLE_TASK_MANAGER)
+}
+
+void GetProcessIdForTabFunction::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  DCHECK_EQ(type, chrome::NOTIFICATION_TASK_MANAGER_CHILD_PROCESSES_DATA_READY);
+  registrar_.RemoveAll();
+  GetProcessIdForTab();
+}
+
+void GetProcessIdForTabFunction::GetProcessIdForTab() {
   TabContentsWrapper* contents = NULL;
   int tab_index = -1;
-  if (!ExtensionTabUtil::GetTabById(tab_id, profile(), include_incognito(),
+  if (!ExtensionTabUtil::GetTabById(tab_id_, profile(), include_incognito(),
                                     NULL, NULL, &contents, &tab_index)) {
     error_ = ExtensionErrorUtils::FormatErrorMessage(
         extension_tabs_module_constants::kTabNotFoundError,
-        base::IntToString(tab_id));
-    return false;
-  }
-
-  // Return the process ID of the tab as an integer.
-  int id = base::GetProcId(contents->web_contents()->
-      GetRenderProcessHost()->GetHandle());
-  result_.reset(Value::CreateIntegerValue(id));
+        base::IntToString(tab_id_));
+    result_.reset(Value::CreateIntegerValue(-1));
+    SendResponse(false);
+  } else {
+    int process_id = contents->web_contents()->GetRenderProcessHost()->GetID();
+    result_.reset(Value::CreateIntegerValue(process_id));
+    SendResponse(true);
+  }
+
+  // Balance the AddRef in the RunImpl.
+  Release();
+}
+
+bool TerminateFunction::RunImpl() {
+#if defined(ENABLE_TASK_MANAGER)
+  EXTENSION_FUNCTION_VALIDATE(args_->GetInteger(0, &process_id_));
+
+  // Add a reference, which is balanced in TerminateProcess to keep the object
+  // around and allow for the callback to be invoked.
+  AddRef();
+
+  // If the task manager is already listening, just post a task to execute
+  // which will invoke the callback once we have returned from this function.
+  // Otherwise, wait for the notification that the task manager is done with
+  // the data gathering.
+  if (ExtensionProcessesEventRouter::GetInstance()->
+          is_task_manager_listening()) {
+    MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
+        &TerminateFunction::TerminateProcess, this));
+  } else {
+    registrar_.Add(this,
+                   chrome::NOTIFICATION_TASK_MANAGER_CHILD_PROCESSES_DATA_READY,
+                   content::NotificationService::AllSources());
+    ExtensionProcessesEventRouter::GetInstance()->
+        DidStartTaskManagerListening();
+  }
+
   return true;
-}
+#else
+  error_ = ExtensionErrorUtils::FormatErrorMessage(
+      errors::kExtensionNotSupported);
+  return false;
+#endif  // defined(ENABLE_TASK_MANAGER)
+}
+
+void TerminateFunction::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  DCHECK_EQ(type, chrome::NOTIFICATION_TASK_MANAGER_CHILD_PROCESSES_DATA_READY);
+  registrar_.RemoveAll();
+  TerminateProcess();
+}
+
+void TerminateFunction::TerminateProcess() {
+  TaskManagerModel* model = TaskManager::GetInstance()->model();
+
+  int count = model->ResourceCount();
+  bool killed = false;
+  bool found = false;
+
+  for (int i = 0; i < count; ++i) {
+    if (model->IsResourceFirstInGroup(i)) {
+      if (process_id_ == model->GetUniqueChildProcessId(i)) {
+        found = true;
+        killed = base::KillProcess(model->GetProcess(i),
+            content::RESULT_CODE_KILLED, true);
+        UMA_HISTOGRAM_COUNTS("ChildProcess.KilledByExtensionAPI", 1);
+        break;
+      }
+    }
+  }
+
+  if (!found) {
+    error_ = ExtensionErrorUtils::FormatErrorMessage(errors::kProcessNotFound,
+        base::IntToString(process_id_));
+    SendResponse(false);
+  } else {
+    result_.reset(Value::CreateBooleanValue(killed));
+    SendResponse(true);
+  }
+
+  // Balance the AddRef in the RunImpl.
+  Release();
+}
+
+GetProcessInfoFunction::GetProcessInfoFunction() {
+}
+
+GetProcessInfoFunction::~GetProcessInfoFunction() {
+}
+
+bool GetProcessInfoFunction::RunImpl() {
+#if defined(ENABLE_TASK_MANAGER)
+  Value* processes = NULL;
+
+  EXTENSION_FUNCTION_VALIDATE(args_->Get(0, &processes));
+  EXTENSION_FUNCTION_VALIDATE(args_->GetBoolean(1, &memory_));
+
+  EXTENSION_FUNCTION_VALIDATE(ExtensionTabUtil::ReadOneOrMoreIntegers(
+      processes, &process_ids_));
+
+  // Add a reference, which is balanced in GatherProcessInfo to keep the object
+  // around and allow for the callback to be invoked.
+  AddRef();
+
+  // If the task manager is already listening, just post a task to execute
+  // which will invoke the callback once we have returned from this function.
+  // Otherwise, wait for the notification that the task manager is done with
+  // the data gathering.
+  if (ExtensionProcessesEventRouter::GetInstance()->
+          is_task_manager_listening()) {
+    MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
+        &GetProcessInfoFunction::GatherProcessInfo, this));
+  } else {
+    registrar_.Add(this,
+                   chrome::NOTIFICATION_TASK_MANAGER_CHILD_PROCESSES_DATA_READY,
+                   content::NotificationService::AllSources());
+    ExtensionProcessesEventRouter::GetInstance()->
+        DidStartTaskManagerListening();
+  }
+  return true;
+
+#else
+  error_ = ExtensionErrorUtils::FormatErrorMessage(
+      errors::kExtensionNotSupported);
+  return false;
+#endif  // defined(ENABLE_TASK_MANAGER)
+}
+
+void GetProcessInfoFunction::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  DCHECK_EQ(type, chrome::NOTIFICATION_TASK_MANAGER_CHILD_PROCESSES_DATA_READY);
+  registrar_.RemoveAll();
+  GatherProcessInfo();
+}
+
+void GetProcessInfoFunction::GatherProcessInfo() {
+  TaskManagerModel* model = TaskManager::GetInstance()->model();
+  DictionaryValue* processes = new DictionaryValue();
+
+  // If there are no process IDs specified, it means we need to return all of
+  // the ones we know of.
+  if (process_ids_.size() == 0) {
+    int resources = model->ResourceCount();
+    for (int i = 0; i < resources; ++i) {
+      if (model->IsResourceFirstInGroup(i)) {
+        int id = model->GetUniqueChildProcessId(i);
+        DictionaryValue* d = CreateProcessFromModel(id, model, i, false);
+        if (memory_)
+          AddMemoryDetails(d, model, i);
+        processes->Set(base::IntToString(id), d);
+      }
+    }
+  } else {
+    int resources = model->ResourceCount();
+    for (int i = 0; i < resources; ++i) {
+      if (model->IsResourceFirstInGroup(i)) {
+        int id = model->GetUniqueChildProcessId(i);
+        std::vector<int>::iterator proc_id = std::find(process_ids_.begin(),
+                                                       process_ids_.end(), id);
+        if (proc_id != process_ids_.end()) {
+          DictionaryValue* d = CreateProcessFromModel(id, model, i, false);
+          if (memory_)
+            AddMemoryDetails(d, model, i);
+          processes->Set(base::IntToString(id), d);
+
+          process_ids_.erase(proc_id);
+          if (process_ids_.size() == 0)
+            break;
+        }
+      }
+    }
+    DCHECK(process_ids_.size() == 0);
+  }
+
+  result_.reset(processes);
+  SendResponse(true);
+
+  // Balance the AddRef in the RunImpl.
+  Release();
+}