src/chrome/browser/memory_purger.cc

   1 // Copyright (c) 2012 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 "chrome/browser/memory_purger.h"
   6
   7 #include <set>
   8
   9 #include "base/allocator/allocator_extension.h"
  10 #include "base/bind.h"
  11 #include "base/threading/thread.h"
  12 #include "chrome/browser/browser_process.h"
  13 #include "chrome/browser/history/history_service.h"
  14 #include "chrome/browser/history/history_service_factory.h"
  15 #include "chrome/browser/profiles/profile_manager.h"
  16 #include "chrome/browser/safe_browsing/database_manager.h"
  17 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
  18 #include "chrome/browser/ui/browser_list.h"
  19 #include "chrome/browser/webdata/web_data_service.h"
  20 #include "chrome/browser/webdata/web_data_service_factory.h"
  21 #include "chrome/common/render_messages.h"
  22 #include "content/public/browser/render_process_host.h"
  23 #include "content/public/browser/render_widget_host.h"
  24 #include "content/public/browser/resource_context.h"
  25 #include "net/proxy/proxy_resolver.h"
  26 #include "net/proxy/proxy_service.h"
  27 #include "net/url_request/url_request_context.h"
  28 #include "net/url_request/url_request_context_getter.h"
  29
  30 using content::BrowserContext;
  31 using content::BrowserThread;
  32 using content::ResourceContext;
  33
  34 // PurgeMemoryHelper -----------------------------------------------------------
  35
  36 // This is a small helper class used to ensure that the objects we want to use
  37 // on multiple threads are properly refed, so they don't get deleted out from
  38 // under us.
  39 class PurgeMemoryIOHelper
  40     : public base::RefCountedThreadSafe<PurgeMemoryIOHelper> {
  41  public:
  42   PurgeMemoryIOHelper() {
  43     safe_browsing_service_ = g_browser_process->safe_browsing_service();
  44   }
  45
  46   void AddRequestContextGetter(
  47       scoped_refptr<net::URLRequestContextGetter> request_context_getter);
  48
  49   void PurgeMemoryOnIOThread();
  50
  51  private:
  52   friend class base::RefCountedThreadSafe<PurgeMemoryIOHelper>;
  53
  54   virtual ~PurgeMemoryIOHelper() {}
  55
  56   typedef scoped_refptr<net::URLRequestContextGetter> RequestContextGetter;
  57   std::vector<RequestContextGetter> request_context_getters_;
  58
  59   scoped_refptr<SafeBrowsingService> safe_browsing_service_;
  60
  61   DISALLOW_COPY_AND_ASSIGN(PurgeMemoryIOHelper);
  62 };
  63
  64 void PurgeMemoryIOHelper::AddRequestContextGetter(
  65     scoped_refptr<net::URLRequestContextGetter> request_context_getter) {
  66   request_context_getters_.push_back(request_context_getter);
  67 }
  68
  69 void PurgeMemoryIOHelper::PurgeMemoryOnIOThread() {
  70   // Ask ProxyServices to purge any memory they can (generally garbage in the
  71   // wrapped ProxyResolver's JS engine).
  72   for (size_t i = 0; i < request_context_getters_.size(); ++i) {
  73     request_context_getters_[i]->GetURLRequestContext()->proxy_service()->
  74         PurgeMemory();
  75   }
  76
  77 #if defined(FULL_SAFE_BROWSING)
  78   safe_browsing_service_->database_manager()->PurgeMemory();
  79 #endif
  80 }
  81
  82 // -----------------------------------------------------------------------------
  83
  84 // static
  85 void MemoryPurger::PurgeAll() {
  86   PurgeBrowser();
  87   PurgeRenderers();
  88
  89   // TODO(pkasting):
  90   // * Tell the plugin processes to release their free memory?  Other stuff?
  91   // * Enumerate what other processes exist and what to do for them.
  92 }
  93
  94 // static
  95 void MemoryPurger::PurgeBrowser() {
  96   // Dump the backing stores.
  97   content::RenderWidgetHost::RemoveAllBackingStores();
  98
  99   // Per-profile cleanup.
 100   scoped_refptr<PurgeMemoryIOHelper> purge_memory_io_helper(
 101       new PurgeMemoryIOHelper());
 102   ProfileManager* profile_manager = g_browser_process->profile_manager();
 103   std::vector<Profile*> profiles(profile_manager->GetLoadedProfiles());
 104   for (size_t i = 0; i < profiles.size(); ++i) {
 105     purge_memory_io_helper->AddRequestContextGetter(
 106         make_scoped_refptr(profiles[i]->GetRequestContext()));
 107
 108     // NOTE: Some objects below may be duplicates across profiles.  We could
 109     // conceivably put all these in sets and then iterate over the sets.
 110
 111     // Unload all history backends (freeing memory used to cache sqlite).
 112     // Spinning up the history service is expensive, so we avoid doing it if it
 113     // hasn't been done already.
 114     HistoryService* history_service =
 115         HistoryServiceFactory::GetForProfileWithoutCreating(profiles[i]);
 116     if (history_service)
 117       history_service->UnloadBackend();
 118
 119     // Unload all web databases (freeing memory used to cache sqlite).
 120     WebDataServiceWrapper* wds_wrapper =
 121         WebDataServiceFactory::GetForProfileIfExists(
 122             profiles[i], Profile::EXPLICIT_ACCESS);
 123     if (wds_wrapper && wds_wrapper->GetWebData().get())
 124       wds_wrapper->GetWebData()->UnloadDatabase();
 125
 126     BrowserContext::PurgeMemory(profiles[i]);
 127   }
 128
 129   BrowserThread::PostTask(
 130       BrowserThread::IO, FROM_HERE,
 131       base::Bind(&PurgeMemoryIOHelper::PurgeMemoryOnIOThread,
 132                  purge_memory_io_helper.get()));
 133
 134   // TODO(pkasting):
 135   // * Purge AppCache memory.  Not yet implemented sufficiently.
 136   // * Browser-side DatabaseTracker.  Not implemented sufficiently.
 137
 138   // Tell our allocator to release any free pages it's still holding.
 139   //
 140   // TODO(pkasting): A lot of the above calls kick off actions on other threads.
 141   // Maybe we should find a way to avoid calling this until those actions
 142   // complete?
 143   base::allocator::ReleaseFreeMemory();
 144 }
 145
 146 // static
 147 void MemoryPurger::PurgeRenderers() {
 148   // Direct all renderers to free everything they can.
 149   //
 150   // Concern: Telling a bunch of renderer processes to destroy their data may
 151   // cause them to page everything in to do it, which could take a lot of time/
 152   // cause jank.
 153   for (content::RenderProcessHost::iterator i(
 154           content::RenderProcessHost::AllHostsIterator());
 155        !i.IsAtEnd(); i.Advance())
 156     PurgeRendererForHost(i.GetCurrentValue());
 157 }
 158
 159 // static
 160 void MemoryPurger::PurgeRendererForHost(content::RenderProcessHost* host) {
 161   // Direct the renderer to free everything it can.
 162   host->Send(new ChromeViewMsg_PurgeMemory());
 163 }