heap-layout-tracer.cc

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// Copyright 2021 the V8 project 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 "src/heap/heap-layout-tracer.h"
 
#include <iostream>
 
#include "src/heap/new-spaces.h"
#include "src/heap/paged-spaces.h"
#include "src/heap/read-only-spaces.h"
#include "src/heap/spaces-inl.h"
 
namespace v8 {
namespace internal {
 
namespace {
 
constexpr const char* TypeToCollectorName(v8::GCType gc_type) {
  switch (gc_type) {
    case kGCTypeScavenge:
      return "Scavenger";
    case kGCTypeMarkSweepCompact:
      return "Mark-Compact";
    case kGCTypeMinorMarkSweep:
      return "Minor Mark-Sweep";
    default:
      break;
  }
  return "Unknown collector";
}
 
}  // namespace
 
// static
void HeapLayoutTracer::GCProloguePrintHeapLayout(v8::Isolate* isolate,
                                                 v8::GCType gc_type,
                                                 v8::GCCallbackFlags flags,
                                                 void* data) {
  Heap* heap = reinterpret_cast<i::Isolate*>(isolate)->heap();
  // gc_count_ will increase after this callback, manually add 1.
  PrintF("Before GC:%d,", heap->gc_count() + 1);
  PrintF("collector_name:%s\n", TypeToCollectorName(gc_type));
  PrintHeapLayout(std::cout, heap);
}
 
// static
void HeapLayoutTracer::GCEpiloguePrintHeapLayout(v8::Isolate* isolate,
                                                 v8::GCType gc_type,
                                                 v8::GCCallbackFlags flags,
                                                 void* data) {
  Heap* heap = reinterpret_cast<i::Isolate*>(isolate)->heap();
  PrintF("After GC:%d,", heap->gc_count());
  PrintF("collector_name:%s\n", TypeToCollectorName(gc_type));
  PrintHeapLayout(std::cout, heap);
}
 
// static
void HeapLayoutTracer::PrintMemoryChunk(std::ostream& os,
                                        const MemoryChunkMetadata& chunk,
                                        const char* owner_name) {
  os << "{owner:" << owner_name << ","
     << "address:" << &chunk << ","
     << "size:" << chunk.size() << ","
     << "allocated_bytes:" << chunk.allocated_bytes() << ","
     << "wasted_memory:" << chunk.wasted_memory() << "}" << std::endl;
}
 
// static
void HeapLayoutTracer::PrintHeapLayout(std::ostream& os, Heap* heap) {
  if (v8_flags.minor_ms) {
    for (const PageMetadata* page : *heap->paged_new_space()) {
      PrintMemoryChunk(os, *page, "new_space");
    }
  } else {
    const SemiSpaceNewSpace* semi_space_new_space =
        SemiSpaceNewSpace::From(heap->new_space());
    for (const PageMetadata* page : semi_space_new_space->to_space()) {
      PrintMemoryChunk(os, *page, "to_space");
    }
 
    for (const PageMetadata* page : semi_space_new_space->from_space()) {
      PrintMemoryChunk(os, *page, "from_space");
    }
  }
 
  OldGenerationMemoryChunkIterator it(heap);
  MutablePageMetadata* chunk;
  while ((chunk = it.next()) != nullptr) {
    PrintMemoryChunk(os, *chunk, ToString(chunk->owner()->identity()));
  }
 
  for (ReadOnlyPageMetadata* page : heap->read_only_space()->pages()) {
    PrintMemoryChunk(os, *page, "ro_space");
  }
}
}  // namespace internal
}  // namespace v8