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The C and C++ Include Header Files

/usr/include/nodejs/deps/v8/include/cppgc/prefinalizer.h


$ cat -n /usr/include/nodejs/deps/v8/include/cppgc/prefinalizer.h

     1	// Copyright 2020 the V8 project authors. All rights reserved.
     2	// Use of this source code is governed by a BSD-style license that can be
     3	// found in the LICENSE file.
     4	
     5	#ifndef INCLUDE_CPPGC_PREFINALIZER_H_
     6	#define INCLUDE_CPPGC_PREFINALIZER_H_
     7	
     8	#include "cppgc/internal/compiler-specific.h"
     9	#include "cppgc/liveness-broker.h"
    10	
    11	namespace cppgc {
    12	
    13	namespace internal {
    14	
    15	class V8_EXPORT PrefinalizerRegistration final {
    16	 public:
    17	  using Callback = bool (*)(const cppgc::LivenessBroker&, void*);
    18	
    19	  PrefinalizerRegistration(void*, Callback);
    20	
    21	  void* operator new(size_t, void* location) = delete;
    22	  void* operator new(size_t) = delete;
    23	};
    24	
    25	}  // namespace internal
    26	
    27	/**
    28	 * Macro must be used in the private section of `Class` and registers a
    29	 * prefinalization callback `void Class::PreFinalizer()`. The callback is
    30	 * invoked on garbage collection after the collector has found an object to be
    31	 * dead.
    32	 *
    33	 * Callback properties:
    34	 * - The callback is invoked before a possible destructor for the corresponding
    35	 *   object.
    36	 * - The callback may access the whole object graph, irrespective of whether
    37	 *   objects are considered dead or alive.
    38	 * - The callback is invoked on the same thread as the object was created on.
    39	 *
    40	 * Example:
    41	 * \code
    42	 * class WithPrefinalizer : public GarbageCollected<WithPrefinalizer> {
    43	 *   CPPGC_USING_PRE_FINALIZER(WithPrefinalizer, Dispose);
    44	 *
    45	 *  public:
    46	 *   void Trace(Visitor*) const {}
    47	 *   void Dispose() { prefinalizer_called = true; }
    48	 *   ~WithPrefinalizer() {
    49	 *     // prefinalizer_called == true
    50	 *   }
    51	 *  private:
    52	 *   bool prefinalizer_called = false;
    53	 * };
    54	 * \endcode
    55	 */
    56	#define CPPGC_USING_PRE_FINALIZER(Class, PreFinalizer)                         \
    57	 public:                                                                       \
    58	  static bool InvokePreFinalizer(const cppgc::LivenessBroker& liveness_broker, \
    59	                                 void* object) {                               \
    60	    static_assert(cppgc::IsGarbageCollectedOrMixinTypeV<Class>,                \
    61	                  "Only garbage collected objects can have prefinalizers");    \
    62	    Class* self = static_cast<Class*>(object);                                 \
    63	    if (liveness_broker.IsHeapObjectAlive(self)) return false;                 \
    64	    self->PreFinalizer();                                                      \
    65	    return true;                                                               \
    66	  }                                                                            \
    67	                                                                               \
    68	 private:                                                                      \
    69	  CPPGC_NO_UNIQUE_ADDRESS cppgc::internal::PrefinalizerRegistration            \
    70	      prefinalizer_dummy_{this, Class::InvokePreFinalizer};                    \
    71	  static_assert(true, "Force semicolon.")
    72	
    73	}  // namespace cppgc
    74	
    75	#endif  // INCLUDE_CPPGC_PREFINALIZER_H_