Tidy heap snapshotting implementation.

third_party/WebKit/Source/platform/heap/HeapPage.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 118 matching lines @@
         Heap::decreaseAllocatedSpace(page->size());
         Heap::orphanedPagePool()->addOrphanedPage(heapIndex(), page);
     }
     m_firstPage = nullptr;
 }
 
 void BaseHeap::takeSnapshot(const String& dumpBaseName, ThreadState::GCSnapshotInfo& info)
 {
     // |dumpBaseName| at this point is "blink_gc/thread_X/heaps/HeapName"
     WebMemoryAllocatorDump* allocatorDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(dumpBaseName);
-    size_t pageIndex = 0;
-    size_t heapTotalFreeSize = 0;
-    size_t heapTotalFreeCount = 0;
+    size_t pageCount = 0;
+    BasePage::HeapSnapshotInfo heapInfo;
     for (BasePage* page = m_firstUnsweptPage; page; page = page->next()) {
-        size_t heapPageFreeSize = 0;
-        size_t heapPageFreeCount = 0;
-        page->takeSnapshot(dumpBaseName, pageIndex, info, &heapPageFreeSize, &heapPageFreeCount);
-        heapTotalFreeSize += heapPageFreeSize;
-        heapTotalFreeCount += heapPageFreeCount;
-        pageIndex++;
+        String dumpName = dumpBaseName + String::format("/pages/page_%lu", static_cast<unsigned long>(pageCount++));
+        WebMemoryAllocatorDump* pageDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(dumpName);
+
+        page->takeSnapshot(pageDump, info, heapInfo);
     }
-    allocatorDump->addScalar("blink_page_count", "objects", pageIndex);
+    allocatorDump->addScalar("blink_page_count", "objects", pageCount);
 
     // When taking a full dump (w/ freelist), both the /buckets and /pages
     // report their free size but they are not meant to be added together.
     // Therefore, here we override the free_size of the parent heap to be
     // equal to the free_size of the sum of its heap pages.
-    allocatorDump->addScalar("free_size", "bytes", heapTotalFreeSize);
-    allocatorDump->addScalar("free_count", "objects", heapTotalFreeCount);
+    allocatorDump->addScalar("free_size", "bytes", heapInfo.freeSize);
+    allocatorDump->addScalar("free_count", "objects", heapInfo.freeCount);
 }
 
 #if ENABLE(ASSERT)
 BasePage* BaseHeap::findPageFromAddress(Address address)
 {
     for (BasePage* page = m_firstPage; page; page = page->next()) {
         if (page->contains(address))
             return page;
     }
     for (BasePage* page = m_firstUnsweptPage; page; page = page->next()) {
@@ skipping 1216 matching lines @@
     // cross thread pointer usage.
 #if defined(ADDRESS_SANITIZER)
     // This needs to zap poisoned memory as well.
     // Force unpoison memory before memset.
     ASAN_UNPOISON_MEMORY_REGION(payload(), payloadSize());
 #endif
     OrphanedPagePool::asanDisabledMemset(payload(), OrphanedPagePool::orphanedZapValue, payloadSize());
     BasePage::markOrphaned();
 }
 
-void NormalPage::takeSnapshot(String dumpName, size_t pageIndex, ThreadState::GCSnapshotInfo& info, size_t* outFreeSize, size_t* outFreeCount)
+void NormalPage::takeSnapshot(WebMemoryAllocatorDump* pageDump, ThreadState::GCSnapshotInfo& info, HeapSnapshotInfo& heapInfo)
 {
-    dumpName.append(String::format("/pages/page_%lu", static_cast<unsigned long>(pageIndex)));
-    WebMemoryAllocatorDump* pageDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(dumpName);
-
     HeapObjectHeader* header = nullptr;
     size_t liveCount = 0;
     size_t deadCount = 0;
     size_t freeCount = 0;
     size_t liveSize = 0;
     size_t deadSize = 0;
     size_t freeSize = 0;
     for (Address headerAddress = payload(); headerAddress < payloadEnd(); headerAddress += header->size()) {
         header = reinterpret_cast<HeapObjectHeader*>(headerAddress);
         if (header->isFree()) {
@@ skipping 15 matching lines @@
             info.deadSize[gcInfoIndex] += header->size();
         }
     }
 
     pageDump->addScalar("live_count", "objects", liveCount);
     pageDump->addScalar("dead_count", "objects", deadCount);
     pageDump->addScalar("free_count", "objects", freeCount);
     pageDump->addScalar("live_size", "bytes", liveSize);
     pageDump->addScalar("dead_size", "bytes", deadSize);
     pageDump->addScalar("free_size", "bytes", freeSize);
-    *outFreeSize = freeSize;
-    *outFreeCount = freeCount;
+    heapInfo.freeSize += freeSize;
+    heapInfo.freeCount += freeCount;
 }
 
 #if ENABLE(ASSERT)
 bool NormalPage::contains(Address addr)
 {
     Address blinkPageStart = roundToBlinkPageStart(address());
     ASSERT(blinkPageStart == address() - blinkGuardPageSize); // Page is at aligned address plus guard page size.
     return blinkPageStart <= addr && addr < blinkPageStart + blinkPageSize;
 }
 #endif
@@ skipping 74 matching lines @@
 }
 
 void LargeObjectPage::markOrphaned()
 {
     // Zap the payload with a recognizable value to detect any incorrect
     // cross thread pointer usage.
     OrphanedPagePool::asanDisabledMemset(payload(), OrphanedPagePool::orphanedZapValue, payloadSize());
     BasePage::markOrphaned();
 }
 
-void LargeObjectPage::takeSnapshot(String dumpName, size_t pageIndex, ThreadState::GCSnapshotInfo& info, size_t* outFreeSize, size_t* outFreeCount)
+void LargeObjectPage::takeSnapshot(WebMemoryAllocatorDump* pageDump, ThreadState::GCSnapshotInfo& info, HeapSnapshotInfo&)
 {
-    dumpName.append(String::format("/pages/page_%lu", static_cast<unsigned long>(pageIndex)));
-    WebMemoryAllocatorDump* pageDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(dumpName);
-
     size_t liveSize = 0;
     size_t deadSize = 0;
     size_t liveCount = 0;
     size_t deadCount = 0;
     HeapObjectHeader* header = heapObjectHeader();
     size_t gcInfoIndex = header->gcInfoIndex();
     size_t payloadSize = header->payloadSize();
     if (header->isMarked()) {
         liveCount = 1;
         liveSize += payloadSize;
@@ skipping 57 matching lines @@
 
     m_hasEntries = true;
     size_t index = hash(address);
     ASSERT(!(index & 1));
     Address cachePage = roundToBlinkPageStart(address);
     m_entries[index + 1] = m_entries[index];
     m_entries[index] = cachePage;
 }
 
 } // namespace blink