Create an API around WorkerService that chrome consumes. Rename the existing WorkerService to Wor...

content/browser/worker_host/worker_service.cc

-// Copyright (c) 2011 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 "content/browser/worker_host/worker_service.h"
-
-#include <string>
-
-#include "base/command_line.h"
-#include "base/logging.h"
-#include "base/sys_info.h"
-#include "base/threading/thread.h"
-#include "content/browser/resource_context.h"
-#include "content/browser/worker_host/worker_message_filter.h"
-#include "content/browser/worker_host/worker_process_host.h"
-#include "content/browser/worker_host/worker_service_observer.h"
-#include "content/common/view_messages.h"
-#include "content/common/worker_messages.h"
-#include "content/public/common/content_switches.h"
-#include "content/public/common/process_type.h"
-#include "net/base/registry_controlled_domain.h"
-
-using content::BrowserThread;
-
-const int WorkerService::kMaxWorkerProcessesWhenSharing = 10;
-const int WorkerService::kMaxWorkersWhenSeparate = 64;
-const int WorkerService::kMaxWorkersPerTabWhenSeparate = 16;
-
-WorkerService* WorkerService::GetInstance() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  return Singleton<WorkerService>::get();
-}
-
-WorkerService::WorkerService() : next_worker_route_id_(0) {
-}
-
-WorkerService::~WorkerService() {
-  // The observers in observers_ can't be used here because they might be
-  // gone already.
-}
-
-void WorkerService::OnWorkerMessageFilterClosing(WorkerMessageFilter* filter) {
-  for (BrowserChildProcessHost::Iterator iter(content::PROCESS_TYPE_WORKER);
-     !iter.Done(); ++iter) {
-    WorkerProcessHost* worker = static_cast<WorkerProcessHost*>(*iter);
-    worker->FilterShutdown(filter);
-  }
-
-  // See if that process had any queued workers.
-  for (WorkerProcessHost::Instances::iterator i = queued_workers_.begin();
-       i != queued_workers_.end();) {
-    i->RemoveFilters(filter);
-    if (i->NumFilters() == 0) {
-      i = queued_workers_.erase(i);
-    } else {
-      ++i;
-    }
-  }
-
-  // Also, see if that process had any pending shared workers.
-  for (WorkerProcessHost::Instances::iterator iter =
-           pending_shared_workers_.begin();
-       iter != pending_shared_workers_.end(); ) {
-    iter->worker_document_set()->RemoveAll(filter);
-    if (iter->worker_document_set()->IsEmpty()) {
-      iter = pending_shared_workers_.erase(iter);
-    } else {
-      ++iter;
-    }
-  }
-
-  // Either a worker proceess has shut down, in which case we can start one of
-  // the queued workers, or a renderer has shut down, in which case it doesn't
-  // affect anything.  We call this function in both scenarios because then we
-  // don't have to keep track which filters are from worker processes.
-  TryStartingQueuedWorker();
-}
-
-void WorkerService::CreateWorker(
-    const ViewHostMsg_CreateWorker_Params& params,
-    int route_id,
-    WorkerMessageFilter* filter,
-    const content::ResourceContext& resource_context) {
-  // Generate a unique route id for the browser-worker communication that's
-  // unique among all worker processes.  That way when the worker process sends
-  // a wrapped IPC message through us, we know which WorkerProcessHost to give
-  // it to.
-  WorkerProcessHost::WorkerInstance instance(
-      params.url,
-      params.name,
-      next_worker_route_id(),
-      0,
-      params.script_resource_appcache_id,
-      &resource_context);
-  instance.AddFilter(filter, route_id);
-  instance.worker_document_set()->Add(
-      filter, params.document_id, filter->render_process_id(),
-      params.render_view_route_id);
-
-  CreateWorkerFromInstance(instance);
-}
-
-void WorkerService::LookupSharedWorker(
-    const ViewHostMsg_CreateWorker_Params& params,
-    int route_id,
-    WorkerMessageFilter* filter,
-    const content::ResourceContext* resource_context,
-    bool* exists,
-    bool* url_mismatch) {
-  *exists = true;
-  WorkerProcessHost::WorkerInstance* instance = FindSharedWorkerInstance(
-      params.url, params.name, resource_context);
-
-  if (!instance) {
-    // If no worker instance currently exists, we need to create a pending
-    // instance - this is to make sure that any subsequent lookups passing a
-    // mismatched URL get the appropriate url_mismatch error at lookup time.
-    // Having named shared workers was a Really Bad Idea due to details like
-    // this.
-    instance = CreatePendingInstance(params.url, params.name, resource_context);
-    *exists = false;
-  }
-
-  // Make sure the passed-in instance matches the URL - if not, return an
-  // error.
-  if (params.url != instance->url()) {
-    *url_mismatch = true;
-    *exists = false;
-  } else {
-    *url_mismatch = false;
-    // Add our route ID to the existing instance so we can send messages to it.
-    instance->AddFilter(filter, route_id);
-
-    // Add the passed filter/document_id to the worker instance.
-    // TODO(atwilson): This won't work if the message is from a worker process.
-    // We don't support that yet though (this message is only sent from
-    // renderers) but when we do, we'll need to add code to pass in the current
-    // worker's document set for nested workers.
-    instance->worker_document_set()->Add(
-        filter, params.document_id, filter->render_process_id(),
-        params.render_view_route_id);
-  }
-}
-
-void WorkerService::CancelCreateDedicatedWorker(
-    int route_id,
-    WorkerMessageFilter* filter) {
-
-  NOTREACHED();
-}
-
-void WorkerService::ForwardToWorker(const IPC::Message& message,
-                                    WorkerMessageFilter* filter) {
-  for (BrowserChildProcessHost::Iterator iter(content::PROCESS_TYPE_WORKER);
-       !iter.Done(); ++iter) {
-    WorkerProcessHost* worker = static_cast<WorkerProcessHost*>(*iter);
-    if (worker->FilterMessage(message, filter))
-      return;
-  }
-
-  // TODO(jabdelmalek): tell filter that callee is gone
-}
-
-void WorkerService::DocumentDetached(unsigned long long document_id,
-                                     WorkerMessageFilter* filter) {
-  // Any associated shared workers can be shut down.
-  for (BrowserChildProcessHost::Iterator iter(content::PROCESS_TYPE_WORKER);
-       !iter.Done(); ++iter) {
-    WorkerProcessHost* worker = static_cast<WorkerProcessHost*>(*iter);
-    worker->DocumentDetached(filter, document_id);
-  }
-
-  // Remove any queued shared workers for this document.
-  for (WorkerProcessHost::Instances::iterator iter = queued_workers_.begin();
-       iter != queued_workers_.end();) {
-
-    iter->worker_document_set()->Remove(filter, document_id);
-    if (iter->worker_document_set()->IsEmpty()) {
-      iter = queued_workers_.erase(iter);
-      continue;
-    }
-    ++iter;
-  }
-
-  // Remove the document from any pending shared workers.
-  for (WorkerProcessHost::Instances::iterator iter =
-           pending_shared_workers_.begin();
-       iter != pending_shared_workers_.end(); ) {
-    iter->worker_document_set()->Remove(filter, document_id);
-    if (iter->worker_document_set()->IsEmpty()) {
-      iter = pending_shared_workers_.erase(iter);
-    } else {
-      ++iter;
-    }
-  }
-}
-
-bool WorkerService::CreateWorkerFromInstance(
-    WorkerProcessHost::WorkerInstance instance) {
-  // TODO(michaeln): We need to ensure that a process is working
-  // on behalf of a single browser context. The process sharing logic below
-  // does not ensure that. Consider making WorkerService a per browser context
-  // object to help with this.
-  WorkerProcessHost* worker = NULL;
-  if (CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kWebWorkerProcessPerCore)) {
-    worker = GetProcessToFillUpCores();
-  } else if (CommandLine::ForCurrentProcess()->HasSwitch(
-                 switches::kWebWorkerShareProcesses)) {
-    worker = GetProcessForDomain(instance.url());
-  } else {  // One process per worker.
-    if (!CanCreateWorkerProcess(instance)) {
-      queued_workers_.push_back(instance);
-      return true;
-    }
-  }
-
-  // Check to see if this shared worker is already running (two pages may have
-  // tried to start up the worker simultaneously).
-  // See if a worker with this name already exists.
-  WorkerProcessHost::WorkerInstance* existing_instance =
-      FindSharedWorkerInstance(
-          instance.url(), instance.name(), instance.resource_context());
-  WorkerProcessHost::WorkerInstance::FilterInfo filter_info =
-      instance.GetFilter();
-  // If this worker is already running, no need to create a new copy. Just
-  // inform the caller that the worker has been created.
-  if (existing_instance) {
-    // Walk the worker's filter list to see if this client is listed. If not,
-    // then it means that the worker started by the client already exited so
-    // we should not attach to this new one (http://crbug.com/29243).
-    if (!existing_instance->HasFilter(filter_info.first, filter_info.second))
-      return false;
-    filter_info.first->Send(new ViewMsg_WorkerCreated(filter_info.second));
-    return true;
-  }
-
-  // Look to see if there's a pending instance.
-  WorkerProcessHost::WorkerInstance* pending = FindPendingInstance(
-      instance.url(), instance.name(), instance.resource_context());
-  // If there's no instance *and* no pending instance (or there is a pending
-  // instance but it does not contain our filter info), then it means the
-  // worker started up and exited already. Log a warning because this should
-  // be a very rare occurrence and is probably a bug, but it *can* happen so
-  // handle it gracefully.
-  if (!pending ||
-      !pending->HasFilter(filter_info.first, filter_info.second)) {
-    DLOG(WARNING) << "Pending worker already exited";
-    return false;
-  }
-
-  // Assign the accumulated document set and filter list for this pending
-  // worker to the new instance.
-  DCHECK(!pending->worker_document_set()->IsEmpty());
-  instance.ShareDocumentSet(*pending);
-  for (WorkerProcessHost::WorkerInstance::FilterList::const_iterator i =
-           pending->filters().begin();
-       i != pending->filters().end(); ++i) {
-    instance.AddFilter(i->first, i->second);
-  }
-  RemovePendingInstances(
-      instance.url(), instance.name(), instance.resource_context());
-
-  // Remove any queued instances of this worker and copy over the filter to
-  // this instance.
-  for (WorkerProcessHost::Instances::iterator iter = queued_workers_.begin();
-       iter != queued_workers_.end();) {
-    if (iter->Matches(instance.url(), instance.name(),
-                      instance.resource_context())) {
-      DCHECK(iter->NumFilters() == 1);
-      WorkerProcessHost::WorkerInstance::FilterInfo filter_info =
-          iter->GetFilter();
-      instance.AddFilter(filter_info.first, filter_info.second);
-      iter = queued_workers_.erase(iter);
-    } else {
-      ++iter;
-    }
-  }
-
-  if (!worker) {
-    WorkerMessageFilter* first_filter = instance.filters().begin()->first;
-    worker = new WorkerProcessHost(
-        instance.resource_context(),
-        first_filter->resource_dispatcher_host());
-    // TODO(atwilson): This won't work if the message is from a worker process.
-    // We don't support that yet though (this message is only sent from
-    // renderers) but when we do, we'll need to add code to pass in the current
-    // worker's document set for nested workers.
-    if (!worker->Init(first_filter->render_process_id())) {
-      delete worker;
-      return false;
-    }
-  }
-
-  // TODO(michaeln): As written, test can fail per my earlier comment in
-  // this method, but that's a bug.
-  // DCHECK(worker->request_context() == instance.request_context());
-
-  worker->CreateWorker(instance);
-  FOR_EACH_OBSERVER(WorkerServiceObserver, observers_,
-                    WorkerCreated(worker, instance));
-  return true;
-}
-
-WorkerProcessHost* WorkerService::GetProcessForDomain(const GURL& url) {
-  int num_processes = 0;
-  std::string domain =
-      net::RegistryControlledDomainService::GetDomainAndRegistry(url);
-  for (BrowserChildProcessHost::Iterator iter(content::PROCESS_TYPE_WORKER);
-       !iter.Done(); ++iter) {
-    num_processes++;
-    WorkerProcessHost* worker = static_cast<WorkerProcessHost*>(*iter);
-    for (WorkerProcessHost::Instances::const_iterator instance =
-             worker->instances().begin();
-         instance != worker->instances().end(); ++instance) {
-      if (net::RegistryControlledDomainService::GetDomainAndRegistry(
-              instance->url()) == domain) {
-        return worker;
-      }
-    }
-  }
-
-  if (num_processes >= kMaxWorkerProcessesWhenSharing)
-    return GetLeastLoadedWorker();
-
-  return NULL;
-}
-
-WorkerProcessHost* WorkerService::GetProcessToFillUpCores() {
-  int num_processes = 0;
-  BrowserChildProcessHost::Iterator iter(content::PROCESS_TYPE_WORKER);
-  for (; !iter.Done(); ++iter)
-    num_processes++;
-
-  if (num_processes >= base::SysInfo::NumberOfProcessors())
-    return GetLeastLoadedWorker();
-
-  return NULL;
-}
-
-WorkerProcessHost* WorkerService::GetLeastLoadedWorker() {
-  WorkerProcessHost* smallest = NULL;
-  for (BrowserChildProcessHost::Iterator iter(content::PROCESS_TYPE_WORKER);
-       !iter.Done(); ++iter) {
-    WorkerProcessHost* worker = static_cast<WorkerProcessHost*>(*iter);
-    if (!smallest || worker->instances().size() < smallest->instances().size())
-      smallest = worker;
-  }
-
-  return smallest;
-}
-
-bool WorkerService::CanCreateWorkerProcess(
-    const WorkerProcessHost::WorkerInstance& instance) {
-  // Worker can be fired off if *any* parent has room.
-  const WorkerDocumentSet::DocumentInfoSet& parents =
-        instance.worker_document_set()->documents();
-
-  for (WorkerDocumentSet::DocumentInfoSet::const_iterator parent_iter =
-           parents.begin();
-       parent_iter != parents.end(); ++parent_iter) {
-    bool hit_total_worker_limit = false;
-    if (TabCanCreateWorkerProcess(parent_iter->render_process_id(),
-                                  parent_iter->render_view_id(),
-                                  &hit_total_worker_limit)) {
-      return true;
-    }
-    // Return false if already at the global worker limit (no need to continue
-    // checking parent tabs).
-    if (hit_total_worker_limit)
-      return false;
-  }
-  // If we've reached here, none of the parent tabs is allowed to create an
-  // instance.
-  return false;
-}
-
-bool WorkerService::TabCanCreateWorkerProcess(int render_process_id,
-                                              int render_view_id,
-                                              bool* hit_total_worker_limit) {
-  int total_workers = 0;
-  int workers_per_tab = 0;
-  *hit_total_worker_limit = false;
-  for (BrowserChildProcessHost::Iterator iter(content::PROCESS_TYPE_WORKER);
-       !iter.Done(); ++iter) {
-    WorkerProcessHost* worker = static_cast<WorkerProcessHost*>(*iter);
-    for (WorkerProcessHost::Instances::const_iterator cur_instance =
-             worker->instances().begin();
-         cur_instance != worker->instances().end(); ++cur_instance) {
-      total_workers++;
-      if (total_workers >= kMaxWorkersWhenSeparate) {
-        *hit_total_worker_limit = true;
-        return false;
-      }
-      if (cur_instance->RendererIsParent(render_process_id, render_view_id)) {
-        workers_per_tab++;
-        if (workers_per_tab >= kMaxWorkersPerTabWhenSeparate)
-          return false;
-      }
-    }
-  }
-
-  return true;
-}
-
-void WorkerService::TryStartingQueuedWorker() {
-  if (queued_workers_.empty())
-    return;
-
-  for (WorkerProcessHost::Instances::iterator i = queued_workers_.begin();
-       i != queued_workers_.end();) {
-    if (CanCreateWorkerProcess(*i)) {
-      WorkerProcessHost::WorkerInstance instance = *i;
-      queued_workers_.erase(i);
-      CreateWorkerFromInstance(instance);
-
-      // CreateWorkerFromInstance can modify the queued_workers_ list when it
-      // coalesces queued instances after starting a shared worker, so we
-      // have to rescan the list from the beginning (our iterator is now
-      // invalid). This is not a big deal as having any queued workers will be
-      // rare in practice so the list will be small.
-      i = queued_workers_.begin();
-    } else {
-      ++i;
-    }
-  }
-}
-
-bool WorkerService::GetRendererForWorker(int worker_process_id,
-                                         int* render_process_id,
-                                         int* render_view_id) const {
-  for (BrowserChildProcessHost::Iterator iter(content::PROCESS_TYPE_WORKER);
-       !iter.Done(); ++iter) {
-    if (iter->id() != worker_process_id)
-        continue;
-
-    // This code assumes one worker per process, see function comment in header!
-    WorkerProcessHost* worker = static_cast<WorkerProcessHost*>(*iter);
-    WorkerProcessHost::Instances::const_iterator first_instance =
-        worker->instances().begin();
-    if (first_instance == worker->instances().end())
-      return false;
-
-    WorkerDocumentSet::DocumentInfoSet::const_iterator info =
-        first_instance->worker_document_set()->documents().begin();
-    *render_process_id = info->render_process_id();
-    *render_view_id = info->render_view_id();
-    return true;
-  }
-  return false;
-}
-
-const WorkerProcessHost::WorkerInstance* WorkerService::FindWorkerInstance(
-      int worker_process_id) {
-  for (BrowserChildProcessHost::Iterator iter(content::PROCESS_TYPE_WORKER);
-       !iter.Done(); ++iter) {
-    if (iter->id() != worker_process_id)
-        continue;
-
-    WorkerProcessHost* worker = static_cast<WorkerProcessHost*>(*iter);
-    WorkerProcessHost::Instances::const_iterator instance =
-        worker->instances().begin();
-    return instance == worker->instances().end() ? NULL : &*instance;
-  }
-  return NULL;
-}
-
-void WorkerService::AddObserver(WorkerServiceObserver* observer) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  observers_.AddObserver(observer);
-}
-
-void WorkerService::RemoveObserver(WorkerServiceObserver* observer) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  observers_.RemoveObserver(observer);
-}
-
-void WorkerService::NotifyWorkerDestroyed(
-    WorkerProcessHost* process,
-    int worker_route_id) {
-  FOR_EACH_OBSERVER(WorkerServiceObserver, observers_,
-                    WorkerDestroyed(process, worker_route_id));
-}
-
-void WorkerService::NotifyWorkerContextStarted(WorkerProcessHost* process,
-                                               int worker_route_id) {
-  FOR_EACH_OBSERVER(WorkerServiceObserver, observers_,
-                    WorkerContextStarted(process, worker_route_id));
-}
-
-WorkerProcessHost::WorkerInstance*
-WorkerService::FindSharedWorkerInstance(
-    const GURL& url,
-    const string16& name,
-    const content::ResourceContext* resource_context) {
-  for (BrowserChildProcessHost::Iterator iter(content::PROCESS_TYPE_WORKER);
-       !iter.Done(); ++iter) {
-    WorkerProcessHost* worker = static_cast<WorkerProcessHost*>(*iter);
-    for (WorkerProcessHost::Instances::iterator instance_iter =
-             worker->mutable_instances().begin();
-         instance_iter != worker->mutable_instances().end();
-         ++instance_iter) {
-      if (instance_iter->Matches(url, name, resource_context))
-        return &(*instance_iter);
-    }
-  }
-  return NULL;
-}
-
-WorkerProcessHost::WorkerInstance*
-WorkerService::FindPendingInstance(
-    const GURL& url,
-    const string16& name,
-    const content::ResourceContext* resource_context) {
-  // Walk the pending instances looking for a matching pending worker.
-  for (WorkerProcessHost::Instances::iterator iter =
-           pending_shared_workers_.begin();
-       iter != pending_shared_workers_.end();
-       ++iter) {
-    if (iter->Matches(url, name, resource_context)) {
-      return &(*iter);
-    }
-  }
-  return NULL;
-}
-
-
-void WorkerService::RemovePendingInstances(
-    const GURL& url,
-    const string16& name,
-    const content::ResourceContext* resource_context) {
-  // Walk the pending instances looking for a matching pending worker.
-  for (WorkerProcessHost::Instances::iterator iter =
-           pending_shared_workers_.begin();
-       iter != pending_shared_workers_.end(); ) {
-    if (iter->Matches(url, name, resource_context)) {
-      iter = pending_shared_workers_.erase(iter);
-    } else {
-      ++iter;
-    }
-  }
-}
-
-WorkerProcessHost::WorkerInstance*
-WorkerService::CreatePendingInstance(
-    const GURL& url,
-    const string16& name,
-    const content::ResourceContext* resource_context) {
-  // Look for an existing pending shared worker.
-  WorkerProcessHost::WorkerInstance* instance =
-      FindPendingInstance(url, name, resource_context);
-  if (instance)
-    return instance;
-
-  // No existing pending worker - create a new one.
-  WorkerProcessHost::WorkerInstance pending(url, true, name, resource_context);
-  pending_shared_workers_.push_back(pending);
-  return &pending_shared_workers_.back();
-}