Purge memory for DBs in the renderer process.

chrome/renderer/render_thread.cc

 // Copyright (c) 2009 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 "chrome/renderer/render_thread.h"
 
 #include <algorithm>
 #include <map>
 #include <vector>
 
+#if defined(USE_SYSTEM_SQLITE)
+#include <sqlite3.h>
+#else
+#include "third_party/sqlite/preprocessed/sqlite3.h"
+#endif
+
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/nullable_string16.h"
 #include "base/process_util.h"
 #include "base/shared_memory.h"
 #include "base/stats_table.h"
 #include "base/string_util.h"
 #include "base/thread_local.h"
 #include "chrome/common/appcache/appcache_dispatcher.h"
@@ skipping 19 matching lines @@
 #include "chrome/renderer/external_extension.h"
 #include "chrome/renderer/loadtimes_extension_bindings.h"
 #include "chrome/renderer/net/render_dns_master.h"
 #include "chrome/renderer/render_process.h"
 #include "chrome/renderer/render_view.h"
 #include "chrome/renderer/renderer_webkitclient_impl.h"
 #include "chrome/renderer/renderer_web_database_observer.h"
 #include "chrome/renderer/socket_stream_dispatcher.h"
 #include "chrome/renderer/user_script_slave.h"
 #include "ipc/ipc_message.h"
+#include "third_party/tcmalloc/tcmalloc/src/google/malloc_extension.h"
 #include "webkit/api/public/WebCache.h"
 #include "webkit/api/public/WebColor.h"
 #include "webkit/api/public/WebCrossOriginPreflightResultCache.h"
+#include "webkit/api/public/WebDatabase.h"
+#include "webkit/api/public/WebFontCache.h"
+#include "webkit/api/public/WebKit.h"
 #include "webkit/api/public/WebRuntimeFeatures.h"
-#include "webkit/api/public/WebFontCache.h"
-#include "webkit/api/public/WebColor.h"
-#include "webkit/api/public/WebDatabase.h"
-#include "webkit/api/public/WebKit.h"
 #include "webkit/api/public/WebScriptController.h"
 #include "webkit/api/public/WebSecurityPolicy.h"
 #include "webkit/api/public/WebStorageEventDispatcher.h"
 #include "webkit/api/public/WebString.h"
 #include "webkit/extensions/v8/benchmarking_extension.h"
 #include "webkit/extensions/v8/gears_extension.h"
 #include "webkit/extensions/v8/interval_extension.h"
 #include "webkit/extensions/v8/playback_extension.h"
-#include "third_party/tcmalloc/tcmalloc/src/google/malloc_extension.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <objbase.h>
 #endif
 
 using WebKit::WebCache;
 using WebKit::WebCrossOriginPreflightResultCache;
+using WebKit::WebFontCache;
 using WebKit::WebRuntimeFeatures;
-using WebKit::WebFontCache;
 using WebKit::WebSecurityPolicy;
 using WebKit::WebScriptController;
 using WebKit::WebString;
 using WebKit::WebStorageEventDispatcher;
 using WebKit::WebView;
 
 namespace {
 static const unsigned int kCacheStatsDelayMS = 2000 /* milliseconds */;
 static const double kInitialIdleHandlerDelayS = 1.0 /* seconds */;
 
@@ skipping 483 matching lines @@
   // Clear the object cache (as much as possible; some live objects cannot be
   // freed).
   WebCache::clear();
 
   // Clear the font/glyph cache.
   WebFontCache::clear();
 
   // Clear the Cross-Origin Preflight cache.
   WebCrossOriginPreflightResultCache::clear();
 
+  // Release all freeable memory from the SQLite process-global page cache (a
+  // low-level object which backs the Connection-specific page caches).
+  while (sqlite3_release_memory(std::numeric_limits<int>::max()) > 0)

[darin (slow to review), 2009/10/31 22:39:40]

do we compile with -DSQLITE_ENABLE_MEMORY_MANAGEMENT=1 as this post from drh
says we should do:
http://www.mail-archive.com/sqlite-users@sqlite.org/msg30587.html

+    ;
+
   // Repeatedly call the V8 idle notification until it returns true ("nothing
   // more to free").  Note that it makes more sense to do this than to implement
   // a new "delete everything" pass because object references make it difficult
   // to free everything possible in just one pass.
   while (!v8::V8::IdleNotification())
     ;
 
 #if defined(OS_WIN)
   // Tell tcmalloc to release any free pages it's still holding.
   MallocExtension::instance()->ReleaseFreeMemory();
 #endif
 }
 
 void RenderThread::OnPurgePluginListCache(bool reload_pages) {
   EnsureWebKitInitialized();
   // The call below will cause a GetPlugins call with refresh=true, but at this
   // point we already know that the browser has refreshed its list, so disable
   // refresh temporarily to prevent each renderer process causing the list to be
   // regenerated.
   plugin_refresh_allowed_ = false;
   WebKit::resetPluginCache(reload_pages);
   plugin_refresh_allowed_ = true;
 }