Set HistogramEnumerationFunction even when Partitions are initialized

Source/wtf/Partitions.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 27 matching lines @@
 namespace WTF {
 
 bool Partitions::s_initialized;
 
 PartitionAllocatorGeneric Partitions::m_fastMallocAllocator;
 PartitionAllocatorGeneric Partitions::m_bufferAllocator;
 SizeSpecificPartitionAllocator<3328> Partitions::m_objectModelAllocator;
 SizeSpecificPartitionAllocator<1024> Partitions::m_layoutAllocator;
 HistogramEnumerationFunction Partitions::m_histogramEnumeration = nullptr;
 
-void Partitions::initialize(HistogramEnumerationFunction histogramEnumeration)
+void Partitions::initialize()
 {
-    static int lock = 0;
-    // Guard against two threads hitting here in parallel.
-    spinLockLock(&lock);
+    // TODO(bashi): Add ASSERT(isMainThread()).
+    // This could be called before WTF::initialize() is called so we can't
+    // rely on isMainThread() at this point.

[haraken, 2015/06/17 14:20:33]

Sorry, I noticed this file is already including MainThread.h. But I think you
can remove this comment, since it's not a big deal.

[bashi, 2015/06/18 22:53:37]

Removed.

     if (!s_initialized) {
         m_fastMallocAllocator.init();
         m_bufferAllocator.init();
         m_objectModelAllocator.init();
         m_layoutAllocator.init();
-        m_histogramEnumeration = histogramEnumeration;
         s_initialized = true;
     }
-    spinLockUnlock(&lock);
+}
+
+void Partitions::setHistogramEnumeration(HistogramEnumerationFunction histogramEnumeration)
+{
+    ASSERT(!m_histogramEnumeration);
+    m_histogramEnumeration = histogramEnumeration;
 }
 
 void Partitions::shutdown()
 {
     // We could ASSERT here for a memory leak within the partition, but it leads
     // to very hard to diagnose ASSERTs, so it's best to leave leak checking for
     // the valgrind and heapcheck bots, which run without partitions.
     (void) m_layoutAllocator.shutdown();
     (void) m_objectModelAllocator.shutdown();
     (void) m_bufferAllocator.shutdown();
@@ skipping 38 matching lines @@
     // accessed only on the main thread.
     ASSERT(isMainThread());
 
     partitionDumpStatsGeneric(fastMallocPartition(), "fast_malloc_partition", partitionStatsDumper);
     partitionDumpStatsGeneric(bufferPartition(), "buffer_partition", partitionStatsDumper);
     partitionDumpStats(objectModelPartition(), "object_model_partition", partitionStatsDumper);
     partitionDumpStats(layoutPartition(), "layout_partition", partitionStatsDumper);
 }
 
 } // namespace WTF