Re-land: Defer SpdySession destruction to support closing writes

net/spdy/spdy_session_pool.cc

 // Copyright (c) 2012 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 "net/spdy/spdy_session_pool.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/values.h"
 #include "net/base/address_list.h"
@@ skipping 53 matching lines @@
          default_protocol_ <= kProtoSPDYMaximumVersion);
   NetworkChangeNotifier::AddIPAddressObserver(this);
   if (ssl_config_service_.get())
     ssl_config_service_->AddObserver(this);
   CertDatabase::GetInstance()->AddObserver(this);
 }
 
 SpdySessionPool::~SpdySessionPool() {
   CloseAllSessions();
 
+  while (!sessions_.empty()) {
+    // Destroy sessions to enforce that lifetime is scoped to SpdySessionPool.
+    // Write callbacks queued upon session drain are not invoked.
+    RemoveUnavailableSession((*sessions_.begin())->GetWeakPtr());
+  }
+
   if (ssl_config_service_.get())
     ssl_config_service_->RemoveObserver(this);
   NetworkChangeNotifier::RemoveIPAddressObserver(this);
   CertDatabase::GetInstance()->RemoveObserver(this);
 }
 
 base::WeakPtr<SpdySession> SpdySessionPool::CreateAvailableSessionFromSocket(
     const SpdySessionKey& key,
     scoped_ptr<ClientSocketHandle> connection,
     const BoundNetLog& net_log,
@@ skipping 153 matching lines @@
   CloseCurrentSessionsHelper(error, "Closing current sessions.",
                              false /* idle_only */);
 }
 
 void SpdySessionPool::CloseCurrentIdleSessions() {
   CloseCurrentSessionsHelper(ERR_ABORTED, "Closing idle sessions.",
                              true /* idle_only */);
 }
 
 void SpdySessionPool::CloseAllSessions() {
-  while (!sessions_.empty()) {
+  while (!available_sessions_.empty()) {
     CloseCurrentSessionsHelper(ERR_ABORTED, "Closing all sessions.",
                                false /* idle_only */);
   }
 }
 
 base::Value* SpdySessionPool::SpdySessionPoolInfoToValue() const {
   base::ListValue* list = new base::ListValue();
 
   for (AvailableSessionMap::const_iterator it = available_sessions_.begin();
        it != available_sessions_.end(); ++it) {
@@ skipping 15 matching lines @@
       continue;
 
     // For OSs that terminate TCP connections upon relevant network changes
     // there is no need to explicitly close SpdySessions, instead simply mark
     // the sessions as deprecated so they aren't reused.
 #if defined(OS_ANDROID) || defined(OS_WIN) || defined(OS_IOS)
     (*it)->MakeUnavailable();
 #else
     (*it)->CloseSessionOnError(ERR_NETWORK_CHANGED,
                                "Closing current sessions.");
-    DCHECK(!*it);
+    DCHECK((*it)->IsDraining());
 #endif  // defined(OS_ANDROID) || defined(OS_WIN) || defined(OS_IOS)
     DCHECK(!IsSessionAvailable(*it));
   }
   http_server_properties_->ClearAllSpdySettings();
 }
 
 void SpdySessionPool::OnSSLConfigChanged() {
   CloseCurrentSessions(ERR_NETWORK_CHANGED);
 }
 
@@ skipping 88 matching lines @@
   for (WeakSessionList::const_iterator it = current_sessions.begin();
        it != current_sessions.end(); ++it) {
     if (!*it)
       continue;
 
     if (idle_only && (*it)->is_active())
       continue;
 
     (*it)->CloseSessionOnError(error, description);
     DCHECK(!IsSessionAvailable(*it));
-    DCHECK(!*it);
   }
 }
 
 }  // namespace net