src/content/browser/service_worker/service_worker_process_manager.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_PROCESS_MANAGER_H_
   6 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_PROCESS_MANAGER_H_
   7
   8 #include <vector>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "content/common/service_worker/service_worker_status_code.h"
  14
  15 class GURL;
  16
  17 namespace content {
  18
  19 class BrowserContext;
  20 class ServiceWorkerContextWrapper;
  21
  22 // Interacts with the UI thread to keep RenderProcessHosts alive while the
  23 // ServiceWorker system is using them.  Each instance of
  24 // ServiceWorkerProcessManager is destroyed on the UI thread shortly after its
  25 // ServiceWorkerContextCore is destroyed on the IO thread.
  26 class CONTENT_EXPORT ServiceWorkerProcessManager {
  27  public:
  28   // |*this| must be owned by |context_wrapper|->context().
  29   explicit ServiceWorkerProcessManager(
  30       ServiceWorkerContextWrapper* context_wrapper);
  31
  32   ~ServiceWorkerProcessManager();
  33
  34   // Returns a reference to a running process suitable for starting the Service
  35   // Worker at |script_url|. Processes in |process_ids| will be checked in order
  36   // for existence, and if none exist, then a new process will be created. Posts
  37   // |callback| to the IO thread to indicate whether creation succeeded and the
  38   // process ID that has a new reference.
  39   //
  40   // Allocation can fail with SERVICE_WORKER_ERROR_START_WORKER_FAILED if
  41   // RenderProcessHost::Init fails.
  42   void AllocateWorkerProcess(
  43       const std::vector<int>& process_ids,
  44       const GURL& script_url,
  45       const base::Callback<void(ServiceWorkerStatusCode, int process_id)>&
  46           callback) const;
  47
  48   // Drops a reference to a process that was running a Service Worker.  This
  49   // must match a call to AllocateWorkerProcess.
  50   void ReleaseWorkerProcess(int process_id);
  51
  52   // |increment_for_test| and |decrement_for_test| define how to look up a
  53   // process by ID and increment or decrement its worker reference count. This
  54   // must be called before any reference to this object escapes to another
  55   // thread, and is considered part of construction.
  56   void SetProcessRefcountOpsForTest(
  57       const base::Callback<bool(int)>& increment_for_test,
  58       const base::Callback<bool(int)>& decrement_for_test);
  59
  60  private:
  61   bool IncrementWorkerRefcountByPid(int process_id) const;
  62   bool DecrementWorkerRefcountByPid(int process_id) const;
  63
  64   // These fields are only accessed on the UI thread after construction.
  65   // The reference cycle through context_wrapper_ is broken in
  66   // ServiceWorkerContextWrapper::Shutdown().
  67   scoped_refptr<ServiceWorkerContextWrapper> context_wrapper_;
  68   base::Callback<bool(int)> increment_for_test_;
  69   base::Callback<bool(int)> decrement_for_test_;
  70
  71   // Used to double-check that we don't access *this after it's destroyed.
  72   base::WeakPtrFactory<ServiceWorkerProcessManager> weak_this_factory_;
  73   base::WeakPtr<ServiceWorkerProcessManager> weak_this_;
  74 };
  75
  76 }  // namespace content
  77
  78 namespace base {
  79 // Specialized to post the deletion to the UI thread.
  80 template <>
  81 struct CONTENT_EXPORT DefaultDeleter<content::ServiceWorkerProcessManager> {
  82   void operator()(content::ServiceWorkerProcessManager* ptr) const;
  83 };
  84 }  // namespace base
  85
  86 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_PROCESS_MANAGER_H_