src/content/browser/renderer_host/renderer_frame_manager.cc

   1 // Copyright 2013 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 #include "content/browser/renderer_host/renderer_frame_manager.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/logging.h"
  10 #include "base/memory/shared_memory.h"
  11 #include "base/sys_info.h"
  12 #include "content/common/host_shared_bitmap_manager.h"
  13
  14 namespace content {
  15
  16 RendererFrameManager* RendererFrameManager::GetInstance() {
  17   return Singleton<RendererFrameManager>::get();
  18 }
  19
  20 void RendererFrameManager::AddFrame(RendererFrameManagerClient* frame,
  21                                     bool locked) {
  22   RemoveFrame(frame);
  23   if (locked)
  24     locked_frames_[frame] = 1;
  25   else
  26     unlocked_frames_.push_front(frame);
  27   CullUnlockedFrames();
  28 }
  29
  30 void RendererFrameManager::RemoveFrame(RendererFrameManagerClient* frame) {
  31   std::map<RendererFrameManagerClient*, size_t>::iterator locked_iter =
  32       locked_frames_.find(frame);
  33   if (locked_iter != locked_frames_.end())
  34     locked_frames_.erase(locked_iter);
  35   unlocked_frames_.remove(frame);
  36 }
  37
  38 void RendererFrameManager::LockFrame(RendererFrameManagerClient* frame) {
  39   std::list<RendererFrameManagerClient*>::iterator unlocked_iter =
  40     std::find(unlocked_frames_.begin(), unlocked_frames_.end(), frame);
  41   if (unlocked_iter != unlocked_frames_.end()) {
  42     DCHECK(locked_frames_.find(frame) == locked_frames_.end());
  43     unlocked_frames_.remove(frame);
  44     locked_frames_[frame] = 1;
  45   } else {
  46     DCHECK(locked_frames_.find(frame) != locked_frames_.end());
  47     locked_frames_[frame]++;
  48   }
  49 }
  50
  51 void RendererFrameManager::UnlockFrame(RendererFrameManagerClient* frame) {
  52   DCHECK(locked_frames_.find(frame) != locked_frames_.end());
  53   size_t locked_count = locked_frames_[frame];
  54   DCHECK(locked_count);
  55   if (locked_count > 1) {
  56     locked_frames_[frame]--;
  57   } else {
  58     RemoveFrame(frame);
  59     unlocked_frames_.push_front(frame);
  60     CullUnlockedFrames();
  61   }
  62 }
  63
  64 RendererFrameManager::RendererFrameManager() {
  65   max_number_of_saved_frames_ =
  66 #if defined(OS_ANDROID)
  67       1;
  68 #else
  69       std::min(5, 2 + (base::SysInfo::AmountOfPhysicalMemoryMB() / 256));
  70 #endif
  71   max_handles_ = base::SharedMemory::GetHandleLimit() / 8.0f;
  72 }
  73
  74 RendererFrameManager::~RendererFrameManager() {}
  75
  76 void RendererFrameManager::CullUnlockedFrames() {
  77   uint32 saved_frame_limit = max_number_of_saved_frames();
  78
  79   if (unlocked_frames_.size() + locked_frames_.size() > 0) {
  80     float handles_per_frame =
  81         HostSharedBitmapManager::current()->AllocatedBitmapCount() * 1.0f /
  82         (unlocked_frames_.size() + locked_frames_.size());
  83
  84     saved_frame_limit = std::max(
  85         1,
  86         static_cast<int>(std::min(static_cast<float>(saved_frame_limit),
  87                                   max_handles_ / handles_per_frame)));
  88   }
  89   while (!unlocked_frames_.empty() &&
  90          unlocked_frames_.size() + locked_frames_.size() > saved_frame_limit) {
  91     size_t old_size = unlocked_frames_.size();
  92     // Should remove self from list.
  93     unlocked_frames_.back()->EvictCurrentFrame();
  94     DCHECK_EQ(unlocked_frames_.size() + 1, old_size);
  95   }
  96 }
  97
  98 }  // namespace content