Adding freelist statistics to blink gc dump provider.

Source/platform/heap/Heap.cpp

Index: Source/platform/heap/Heap.cpp
diff --git a/Source/platform/heap/Heap.cpp b/Source/platform/heap/Heap.cpp
index d6c57cb4422785de3554b671e96c0070ef35d551..55c674bff40fbe336b3267c92809ae6ce19a4298 100644
--- a/Source/platform/heap/Heap.cpp
+++ b/Source/platform/heap/Heap.cpp
@@ -562,6 +562,11 @@ bool NormalPageHeap::pagesToBeSweptContains(Address address)
 }
 #endif
 
+void NormalPageHeap::takeFreelistSnapshot(const String& dumpName)
+{
+    m_freeList.takeSnapshot(dumpName);
+}
+
 #if ENABLE(GC_PROFILING)
 void NormalPageHeap::snapshotFreeList(TracedValue& json)
 {
@@ -1120,6 +1125,23 @@ int FreeList::bucketIndexForSize(size_t size)
     return index;
 }
 
+void FreeList::takeSnapshot(const String& dumpBaseName)
+{
+    for (size_t i = 0; i < blinkPageSizeLog2; ++i) {
+        size_t entryCount = 0;
+        size_t freeSize = 0;
+        for (FreeListEntry* entry = m_freeLists[i]; entry; entry = entry->next()) {
+            ++entryCount;
+            freeSize += entry->size();
+        }
+
+        String dumpName = dumpBaseName + String::format("/buckets/bucket_%lu", static_cast<unsigned long>(1 << i));

[haraken, 2015/06/23 08:14:49]

I'm just curious, but where is the String::operator+ defined? I think we removed
it since String::operator+ is slow and thus we should encourage developers to
use StringBuilder...

+        WebMemoryAllocatorDump* bucketDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(dumpName);
+        bucketDump->AddScalar("freelist_entry_count", "objects", entryCount);
+        bucketDump->AddScalar("free_size", "bytes", freeSize);
+    }
+}
+
 #if ENABLE(GC_PROFILING)
 void FreeList::getFreeSizeStats(PerBucketFreeListStats bucketStats[], size_t& totalFreeSize) const
 {
@@ -1453,7 +1475,7 @@ void NormalPage::markOrphaned()
 
 void NormalPage::takeSnapshot(String dumpName, size_t pageIndex)
 {
-    dumpName.append(String::format("/page_%lu", static_cast<unsigned long>(pageIndex)));
+    dumpName.append(String::format("/pages/page_%lu", static_cast<unsigned long>(pageIndex)));
     WebMemoryAllocatorDump* pageDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(dumpName);
 
     HeapObjectHeader* header = nullptr;
@@ -1662,7 +1684,7 @@ void LargeObjectPage::markOrphaned()
 
 void LargeObjectPage::takeSnapshot(String dumpName, size_t pageIndex)
 {
-    dumpName.append(String::format("/page_%lu", static_cast<unsigned long>(pageIndex)));
+    dumpName.append(String::format("/pages/page_%lu", static_cast<unsigned long>(pageIndex)));
     WebMemoryAllocatorDump* pageDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(dumpName);
 
     size_t liveSize = 0;