discardable_memory: Using mojo IPC to replace Chrome IPC

components/discardable_memory/service/discardable_shared_memory_manager.cc

 // Copyright 2014 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 "components/discardable_memory/service/discardable_shared_memory_manager.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/atomic_sequence_num.h"
@@ skipping 195 matching lines @@
 }
 
 DiscardableSharedMemoryManager* DiscardableSharedMemoryManager::current() {
   return g_discardable_shared_memory_manager.Pointer();
 }
 
 std::unique_ptr<base::DiscardableMemory>
 DiscardableSharedMemoryManager::AllocateLockedDiscardableMemory(size_t size) {
   DCHECK_NE(size, 0u);
 
-  DiscardableSharedMemoryId new_id =
-      g_next_discardable_shared_memory_id.GetNext();
-  base::ProcessHandle current_process_handle = base::GetCurrentProcessHandle();
+  int32_t new_id = g_next_discardable_shared_memory_id.GetNext();
 
   // Note: Use DiscardableSharedMemoryHeap for in-process allocation
   // of discardable memory if the cost of each allocation is too high.
   base::SharedMemoryHandle handle;
-  AllocateLockedDiscardableSharedMemory(
-      current_process_handle, kInvalidUniqueClientID, size, new_id, &handle);
+  AllocateLockedDiscardableSharedMemory(kInvalidUniqueClientID, size, new_id,
+                                        &handle);
   std::unique_ptr<base::DiscardableSharedMemory> memory(
       new base::DiscardableSharedMemory(handle));
   if (!memory->Map(size))
     base::TerminateBecauseOutOfMemory(size);
   // Close file descriptor to avoid running out.
   memory->Close();
   return base::MakeUnique<DiscardableMemoryImpl>(
       std::move(memory),
       base::Bind(
           &DiscardableSharedMemoryManager::DeletedDiscardableSharedMemory,
@@ skipping 66 matching lines @@
                         static_cast<uint64_t>(resident_size));
       }
 #endif  // defined(COUNT_RESIDENT_BYTES_SUPPORTED)
     }
   }
   return true;
 }
 
 void DiscardableSharedMemoryManager::
     AllocateLockedDiscardableSharedMemoryForClient(
-        base::ProcessHandle process_handle,
         int client_id,
         size_t size,
-        DiscardableSharedMemoryId id,
+        int32_t id,
         base::SharedMemoryHandle* shared_memory_handle) {
-  AllocateLockedDiscardableSharedMemory(process_handle, client_id, size, id,
+  AllocateLockedDiscardableSharedMemory(client_id, size, id,
                                         shared_memory_handle);
 }
 
 void DiscardableSharedMemoryManager::ClientDeletedDiscardableSharedMemory(
-    DiscardableSharedMemoryId id,
+    int32_t id,
     int client_id) {
   DeletedDiscardableSharedMemory(id, client_id);
 }
 
 void DiscardableSharedMemoryManager::ClientRemoved(int client_id) {
   base::AutoLock lock(lock_);
 
   auto it = clients_.find(client_id);
   if (it == clients_.end())
     return;
@@ skipping 41 matching lines @@
     case base::MemoryState::SUSPENDED:
     // Note that SUSPENDED never occurs in the main browser process so far.
     // Fall through.
     case base::MemoryState::UNKNOWN:
       NOTREACHED();
       break;
   }
 }
 
 void DiscardableSharedMemoryManager::AllocateLockedDiscardableSharedMemory(
-    base::ProcessHandle process_handle,
     int client_id,
     size_t size,
-    DiscardableSharedMemoryId id,
+    int32_t id,
     base::SharedMemoryHandle* shared_memory_handle) {
   base::AutoLock lock(lock_);
 
   // Make sure |id| is not already in use.
   MemorySegmentMap& client_segments = clients_[client_id];
   if (client_segments.find(id) != client_segments.end()) {
     LOG(ERROR) << "Invalid discardable shared memory ID";
     *shared_memory_handle = base::SharedMemory::NULLHandle();
     return;
   }
@@ skipping 12 matching lines @@
   if (bytes_allocated_ > limit)
     ReduceMemoryUsageUntilWithinLimit(limit);
 
   std::unique_ptr<base::DiscardableSharedMemory> memory(
       new base::DiscardableSharedMemory);
   if (!memory->CreateAndMap(size)) {
     *shared_memory_handle = base::SharedMemory::NULLHandle();
     return;
   }
 
-  if (!memory->ShareToProcess(process_handle, shared_memory_handle)) {
-    LOG(ERROR) << "Cannot share discardable memory segment";
-    *shared_memory_handle = base::SharedMemory::NULLHandle();
-    return;
-  }
+  *shared_memory_handle = base::SharedMemory::DuplicateHandle(memory->handle());
 
   // Close file descriptor to avoid running out.
   memory->Close();
 
   base::CheckedNumeric<size_t> checked_bytes_allocated = bytes_allocated_;
   checked_bytes_allocated += memory->mapped_size();
   if (!checked_bytes_allocated.IsValid()) {
     *shared_memory_handle = base::SharedMemory::NULLHandle();
     return;
   }
 
   bytes_allocated_ = checked_bytes_allocated.ValueOrDie();
   BytesAllocatedChanged(bytes_allocated_);
 
   scoped_refptr<MemorySegment> segment(new MemorySegment(std::move(memory)));
   client_segments[id] = segment.get();
   segments_.push_back(segment.get());
   std::push_heap(segments_.begin(), segments_.end(), CompareMemoryUsageTime);
 
   if (bytes_allocated_ > memory_limit_)
     ScheduleEnforceMemoryPolicy();
 }
 
 void DiscardableSharedMemoryManager::DeletedDiscardableSharedMemory(
-    DiscardableSharedMemoryId id,
+    int32_t id,
     int client_id) {
   base::AutoLock lock(lock_);
 
   MemorySegmentMap& client_segments = clients_[client_id];
 
   MemorySegmentMap::iterator segment_it = client_segments.find(id);
   if (segment_it == client_segments.end()) {
     LOG(ERROR) << "Invalid discardable shared memory ID";
     return;
   }
@@ skipping 122 matching lines @@
     return;
 
   enforce_memory_policy_pending_ = true;
   DCHECK(enforce_memory_policy_task_runner_);
   enforce_memory_policy_task_runner_->PostDelayedTask(
       FROM_HERE, enforce_memory_policy_callback_,
       base::TimeDelta::FromMilliseconds(kEnforceMemoryPolicyDelayMs));
 }
 
 }  // namespace discardable_memory