discardable_memory: Using mojo IPC to replace Chrome IPC

components/discardable_memory/service/discardable_shared_memory_manager.h

Index: components/discardable_memory/service/discardable_shared_memory_manager.h
diff --git a/components/discardable_memory/service/discardable_shared_memory_manager.h b/components/discardable_memory/service/discardable_shared_memory_manager.h
index 7ccadf18a44b3b1c68a540e9f4647b0d3778bd44..cb42cfb1b04f0738320b4327c57df2f1f40e5baf 100644
--- a/components/discardable_memory/service/discardable_shared_memory_manager.h
+++ b/components/discardable_memory/service/discardable_shared_memory_manager.h
@@ -27,7 +27,7 @@
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/memory_dump_provider.h"
 #include "components/discardable_memory/common/discardable_memory_export.h"
-#include "components/discardable_memory/common/discardable_shared_memory_id.h"
+#include "components/discardable_memory/public/interfaces/discardable_shared_memory_manager.mojom.h"
 
 namespace discardable_memory {
 
@@ -44,9 +44,15 @@ class DISCARDABLE_MEMORY_EXPORT DiscardableSharedMemoryManager
   DiscardableSharedMemoryManager();
   ~DiscardableSharedMemoryManager() override;
 
+  // Create a sigleton instance.
+  static DiscardableSharedMemoryManager* CreateInstance();
+
   // Returns a singleton instance.
   static DiscardableSharedMemoryManager* current();

[reveman, 2016/11/23 17:07:44]

Please rename this to GetInstance() now that we have CreateInstance?

[Peng, 2016/11/24 15:04:37]

Done.

 
+  // Bind the current manager to a mojo interface request.
+  static void Bind(mojom::DiscardableSharedMemoryManagerRequest request);

[reveman, 2016/11/23 17:07:44]

Please make this a member function instead of static.

[Peng, 2016/11/24 15:04:37]

Done.

+
   // Overridden from base::DiscardableMemoryAllocator:
   std::unique_ptr<base::DiscardableMemory> AllocateLockedDiscardableMemory(
       size_t size) override;
@@ -55,20 +61,17 @@ class DISCARDABLE_MEMORY_EXPORT DiscardableSharedMemoryManager
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                     base::trace_event::ProcessMemoryDump* pmd) override;
 
-  // TODO(penghuang): Get ride of the |process_handle| when we switch to mojo.
   // This allocates a discardable memory segment for |process_handle|.
   // A valid shared memory handle is returned on success.
   void AllocateLockedDiscardableSharedMemoryForClient(
-      base::ProcessHandle process_handle,
       int client_id,
       size_t size,
-      DiscardableSharedMemoryId id,
+      int32_t id,
       base::SharedMemoryHandle* shared_memory_handle);
 
   // Call this to notify the manager that client process associated with
   // |client_id| has deleted discardable memory segment with |id|.
-  void ClientDeletedDiscardableSharedMemory(DiscardableSharedMemoryId id,
-                                            int client_id);
+  void ClientDeletedDiscardableSharedMemory(int32_t id, int client_id);
 
   // Call this to notify the manager that client associated with |client_id|
   // has been removed. The manager will use this to release memory segments
@@ -111,15 +114,12 @@ class DISCARDABLE_MEMORY_EXPORT DiscardableSharedMemoryManager
   // base::MemoryCoordinatorClient implementation:
   void OnMemoryStateChange(base::MemoryState state) override;
 
-  // TODO(penghuang): Get ride of the |process_handle| when we switch to mojo.
   void AllocateLockedDiscardableSharedMemory(
-      base::ProcessHandle process_handle,
       int client_id,
       size_t size,
-      DiscardableSharedMemoryId id,
+      int32_t id,
       base::SharedMemoryHandle* shared_memory_handle);
-  void DeletedDiscardableSharedMemory(DiscardableSharedMemoryId id,
-                                      int client_id);
+  void DeletedDiscardableSharedMemory(int32_t id, int client_id);
   void OnMemoryPressure(
       base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
   void ReduceMemoryUsageUntilWithinMemoryLimit();
@@ -131,9 +131,10 @@ class DISCARDABLE_MEMORY_EXPORT DiscardableSharedMemoryManager
   virtual base::Time Now() const;
   virtual void ScheduleEnforceMemoryPolicy();
 
+  int32_t last_client_id_;

[reveman, 2016/11/23 17:07:44]

nit (optional): it's more common in chromium to use next_client_id_ and post
increment. I don't feel strongly about it but I guess it makes more sense as
initially there's not really a "last" id..

[Peng, 2016/11/24 15:04:37]

Done.

+
   base::Lock lock_;
-  typedef base::hash_map<DiscardableSharedMemoryId,
-                         scoped_refptr<MemorySegment>>
+  typedef base::hash_map<int32_t, scoped_refptr<MemorySegment>>

[dcheng, 2016/11/25 00:07:08]

Nit: prefer using A = B; to typedef B A;

[Peng, 2016/11/25 16:41:53]

Done.

       MemorySegmentMap;
   typedef base::hash_map<int, MemorySegmentMap> ClientMap;
   ClientMap clients_;