GCTrace.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: set ts=8 sts=2 et sw=2 tw=80:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef gc_GCTrace_h
#define gc_GCTrace_h

#include "gc/Heap.h"

namespace js {

class ObjectGroup;

namespace gc {

/*
 * Tracing code is declared within this class, so the class can be a friend of
 * something and access private details used for tracing.
 */
class GCTrace {
 public:
  GCTrace() = default;

#ifdef JS_GC_TRACE

  MOZ_MUST_USE bool initTrace(GCRuntime& gc);
  void finishTrace();
  bool traceEnabled();
  void traceNurseryAlloc(Cell* thing, size_t size);
  void traceNurseryAlloc(Cell* thing, AllocKind kind);
  void traceTenuredAlloc(Cell* thing, AllocKind kind);
  void traceCreateObject(JSObject* object);
  void traceMinorGCStart();
  void tracePromoteToTenured(Cell* src, Cell* dst);
  void traceMinorGCEnd();
  void traceMajorGCStart();
  void traceTenuredFinalize(Cell* thing);
  void traceMajorGCEnd();
  void traceTypeNewScript(js::ObjectGroup* group);

 private:
  FILE* gcTraceFile = nullptr;

  HashSet<const JSClass*, DefaultHasher<const JSClass*>, SystemAllocPolicy>
      tracedClasses;
  HashSet<const ObjectGroup*, DefaultHasher<const ObjectGroup*>,
          SystemAllocPolicy>
      tracedGroups;

  void maybeTraceClass(const JSClass* clasp);
  void maybeTraceGroup(ObjectGroup* group);

#else

  MOZ_MUST_USE bool initTrace(GCRuntime& gc) { return true; }
  void finishTrace() {}
  bool traceEnabled() { return false; }
  void traceNurseryAlloc(Cell* thing, size_t size) {}
  void traceNurseryAlloc(Cell* thing, AllocKind kind) {}
  void traceTenuredAlloc(Cell* thing, AllocKind kind) {}
  void traceCreateObject(JSObject* object) {}
  void traceMinorGCStart() {}
  void tracePromoteToTenured(Cell* src, Cell* dst) {}
  void traceMinorGCEnd() {}
  void traceMajorGCStart() {}
  void traceTenuredFinalize(Cell* thing) {}
  void traceMajorGCEnd() {}
  void traceTypeNewScript(js::ObjectGroup* group) {}

#endif
}; /* GCTrace */

extern GCTrace gcTracer;

} /* namespace gc */
} /* namespace js */

#endif