Disk cache: Stop evictions while performing final cleanup....

net/disk_cache/eviction.cc

 // Copyright (c) 2006-2010 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.
 
 // The eviction policy is a very simple pure LRU, so the elements at the end of
 // the list are evicted until kCleanUpMargin free space is available. There is
 // only one list in use (Rankings::NO_USE), and elements are sent to the front
 // of the list whenever they are accessed.
 
 // The new (in-development) eviction policy ads re-use as a factor to evict
@@ skipping 52 matching lines @@
   // when we're actually doing work.
   backend_ = backend;
   rankings_ = &backend->rankings_;
   header_ = &backend_->data_->header;
   max_size_ = LowWaterAdjust(backend_->max_size_);
   new_eviction_ = backend->new_eviction_;
   first_trim_ = true;
   trimming_ = false;
   delay_trim_ = false;
   trim_delays_ = 0;
+  init_ = true;
+}
+
+void Eviction::Stop() {
+  if (!init_)
+    return;

[gavinp, 2010/07/19 22:20:31]

NOTREACHED() ?

[rvargas (doing something else), 2010/07/19 23:48:28]

I added a comment explaining when we'll reach Stop without a call to Init.

+
+  // We want to stop further evictions, so let's pretend that we are busy from
+  // this point on.
+  DCHECK(!trimming_);
+  trimming_ = true;
 }
 
 void Eviction::TrimCache(bool empty) {
   if (backend_->disabled_ || trimming_)
     return;
 
   if (!empty && !ShouldTrim())
     return PostDelayedTrim();
 
   if (new_eviction_)
@@ skipping 419 matching lines @@
               Time::FromInternalValue(last2.get()->Data()->last_used));
   if (last3.get())
     CACHE_UMA(AGE, "HighUseAge", 0,
               Time::FromInternalValue(last3.get()->Data()->last_used));
   if (last4.get())
     CACHE_UMA(AGE, "DeletedAge", 0,
               Time::FromInternalValue(last4.get()->Data()->last_used));
 }
 
 }  // namespace disk_cache