Fix StatsTable::RegisterThread so that it doesn't crash if shared memory...

base/stats_table.cc

 // Copyright (c) 2006-2008 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 "base/stats_table.h"
 
 #include "base/logging.h"
 #include "base/platform_thread.h"
 #include "base/process_util.h"
 #include "base/scoped_ptr.h"
@@ skipping 269 matching lines @@
   // Cleanup our shared memory.
   delete impl_;
 
   // If we are the global table, unregister ourselves.
   if (global_table_ == this)
     global_table_ = NULL;
 }
 
 int StatsTable::RegisterThread(const std::string& name) {
   int slot = 0;
+  if (!impl_)
+    return 0;
 
   // Registering a thread requires that we lock the shared memory
   // so that two threads don't grab the same slot.  Fortunately,
   // thread creation shouldn't happen in inner loops.
   {
     base::SharedMemoryAutoLock lock(impl_->shared_memory());
     slot = FindEmptyThread();
     if (!slot) {
       return 0;
     }
 
-    DCHECK(impl_);
-
     // We have space, so consume a column in the table.
     std::string thread_name = name;
     if (name.empty())
       thread_name = kUnknownName;
     base::strlcpy(impl_->thread_name(slot), thread_name.c_str(),
                   kMaxThreadNameLength);
     *(impl_->thread_tid(slot)) = PlatformThread::CurrentId();
     *(impl_->thread_pid(slot)) = base::GetCurrentProcId();
   }
 
@@ skipping 128 matching lines @@
     iter = counters_.find(name);
     if (iter != counters_.end())
       return iter->second;
   }
 
   // Counter does not exist, so add it.
   return AddCounter(name);
 }
 
 int StatsTable::AddCounter(const std::string& name) {
-  DCHECK(impl_);
-
   if (!impl_)
     return 0;
 
   int counter_id = 0;
   {
     // To add a counter to the shared memory, we need the
     // shared memory lock.
     base::SharedMemoryAutoLock lock(impl_->shared_memory());
 
     // We have space, so create a new counter.
@@ skipping 88 matching lines @@
   if (!slot && !(slot = table->RegisterThread("")))
       return NULL;
 
   // Find the counter id for the counter.
   std::string str_name(name);
   int counter = table->FindCounter(str_name);
 
   // Now we can find the location in the table.
   return table->GetLocation(counter, slot);
 }