Use one worker process per domain until we hit the maximum count of 10, then reuse processes.

Also add a test mode --webworker-process-per-core to create a worker process per worker until we hit the number of cores, then reuse.

Review URL: http://codereview.chromium.org/61001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@13279 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 95 insertions, 17 deletions

diff --git a/chrome/browser/worker_host/worker_process_host.h b/chrome/browser/worker_host/worker_process_host.h
index cf8072c..5432396 100644
--- a/chrome/browser/worker_host/worker_process_host.h
+++ b/chrome/browser/worker_host/worker_process_host.h
@@ -35,6 +35,22 @@ class WorkerProcessHost : public ChildProcessHost {
 
   void RendererShutdown(ResourceMessageFilter* filter);
 
+ protected:
+  friend class WorkerService;
+
+  // Contains information about each worker instance, needed to forward messages
+  // between the renderer and worker processes.
+  struct WorkerInstance {
+    GURL url;
+    int render_view_route_id;
+    int worker_route_id;
+    int renderer_route_id;
+    ResourceMessageFilter* filter;
+  };
+
+  typedef std::list<WorkerInstance> Instances;
+  const Instances& instances() const { return instances_; }
+
  private:
   // ResourceDispatcherHost::Receiver implementation:
   virtual URLRequestContext* GetRequestContext(
@@ -49,17 +65,6 @@ class WorkerProcessHost : public ChildProcessHost {
   // Updates the title shown in the task manager.
   void UpdateTitle();
 
-  // Contains information about each worker instance, needed to forward messages
-  // between the renderer and worker processes.
-  struct WorkerInstance {
-    GURL url;
-    int render_view_route_id;
-    int worker_route_id;
-    int renderer_route_id;
-    ResourceMessageFilter* filter;
-  };
-
-  typedef std::list<WorkerInstance> Instances;
   Instances instances_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkerProcessHost);
diff --git a/chrome/browser/worker_host/worker_service.cc b/chrome/browser/worker_host/worker_service.cc
index 675326f..8151d9b 100644
--- a/chrome/browser/worker_host/worker_service.cc
+++ b/chrome/browser/worker_host/worker_service.cc
@@ -4,13 +4,21 @@
 
 #include "chrome/browser/worker_host/worker_service.h"
 
+#include "base/command_line.h"
 #include "base/singleton.h"
+#include "base/sys_info.h"
 #include "base/thread.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/plugin_service.h"
 #include "chrome/browser/worker_host/worker_process_host.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
 #include "chrome/browser/renderer_host/resource_message_filter.h"
+#include "chrome/common/chrome_switches.h"
+#include "net/base/registry_controlled_domain.h"
+
+namespace {
+static const int kMaxWorkerProcesses = 10;
+}
 
 WorkerService* WorkerService::GetInstance() {
   return Singleton<WorkerService>::get();
@@ -27,11 +35,12 @@ bool WorkerService::CreateDedicatedWorker(const GURL &url,
                                           ResourceMessageFilter* filter,
                                           int renderer_route_id) {
   WorkerProcessHost* worker = NULL;
-  // One worker process for quick bringup!
-  for (ChildProcessHost::Iterator iter(ChildProcessInfo::WORKER_PROCESS);
-       !iter.Done(); ++iter) {
-    worker = static_cast<WorkerProcessHost*>(*iter);
-    break;
+
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kWebWorkerProcessPerCore)) {
+    worker = GetProcessToFillUpCores();
+  } else {
+    worker = GetProcessForDomain(url);
   }
 
   if (!worker) {
@@ -48,7 +57,6 @@ bool WorkerService::CreateDedicatedWorker(const GURL &url,
   // it to.
   worker->CreateWorker(url, render_view_route_id, ++next_worker_route_id_,
                        renderer_route_id, filter);
-
   return true;
 }
 
@@ -70,3 +78,51 @@ void WorkerService::RendererShutdown(ResourceMessageFilter* filter) {
     worker->RendererShutdown(filter);
   }
 }
+
+WorkerProcessHost* WorkerService::GetProcessForDomain(const GURL& url) {
+  int num_processes = 0;
+  std::string domain =
+      net::RegistryControlledDomainService::GetDomainAndRegistry(url);
+  for (ChildProcessHost::Iterator iter(ChildProcessInfo::WORKER_PROCESS);
+       !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 >= kMaxWorkerProcesses)
+    return GetLeastLoadedWorker();
+
+  return NULL;
+}
+
+WorkerProcessHost* WorkerService::GetProcessToFillUpCores() {
+  int num_processes = 0;
+  ChildProcessHost::Iterator iter(ChildProcessInfo::WORKER_PROCESS);
+  for (; !iter.Done(); ++iter)
+    num_processes++;
+
+  if (num_processes >= base::SysInfo::NumberOfProcessors())
+    return GetLeastLoadedWorker();
+
+  return NULL;
+}
+
+WorkerProcessHost* WorkerService::GetLeastLoadedWorker() {
+  WorkerProcessHost* smallest = NULL;
+  for (ChildProcessHost::Iterator iter(ChildProcessInfo::WORKER_PROCESS);
+       !iter.Done(); ++iter) {
+    WorkerProcessHost* worker = static_cast<WorkerProcessHost*>(*iter);
+    if (!smallest || worker->instances().size() < smallest->instances().size())
+      smallest = worker;
+  }
+
+  return smallest;
+}
diff --git a/chrome/browser/worker_host/worker_service.h b/chrome/browser/worker_host/worker_service.h
index 4f00c15..1aea2aa 100644
--- a/chrome/browser/worker_host/worker_service.h
+++ b/chrome/browser/worker_host/worker_service.h
@@ -44,6 +44,18 @@ class WorkerService {
   WorkerService();
   ~WorkerService();
 
+  // Returns a WorkerProcessHost object if one exists for the given domain, or
+  // NULL if there are no such workers yet.
+  WorkerProcessHost* GetProcessForDomain(const GURL& url);
+
+  // Returns a WorkerProcessHost based on a strategy of creating one worker per
+  // core.
+  WorkerProcessHost* GetProcessToFillUpCores();
+
+  // Returns the WorkerProcessHost from the existing set that has the least
+  // number of worker instance running.
+  WorkerProcessHost* GetLeastLoadedWorker();
+
   int next_worker_route_id_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkerService);
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index c12b578..e5573ca 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -400,6 +400,9 @@ const wchar_t kEnableOutOfProcessDevTools[]    = L"enable-oop-devtools";
 // Enable HTML5 Worker support
 const wchar_t kEnableWebWorkers[]              = L"enable-web-workers";
 
+// Causes the worker process allocation to use as many processes as cores.
+const wchar_t kWebWorkerProcessPerCore[]       = L"web-worker-process-per-core";
+
 // Enables experimental views under gtk.
 const wchar_t kViewsGtk[] = L"views-gtk";
 
diff --git a/chrome/common/chrome_switches.h b/chrome/common/chrome_switches.h
index fb72d4f..4b94a45 100644
--- a/chrome/common/chrome_switches.h
+++ b/chrome/common/chrome_switches.h
@@ -156,6 +156,8 @@ extern const wchar_t kEnableOutOfProcessDevTools[];
 
 extern const wchar_t kEnableWebWorkers[];
 
+extern const wchar_t kWebWorkerProcessPerCore[];
+
 extern const wchar_t kViewsGtk[];
 
 extern const wchar_t kBookmarkMenu[];