Files
node-v0.x-archive/src/node_object_wrap.h
Ben Noordhuis cd96f0aba8 src: don't SetInternalField() in ObjectWrap dtor
Call SetPointerInInternalField(0, NULL) rather than
SetInternalField(0, Undefined()).

Fixes the following spurious NULL pointer dereference in debug builds:

  #0  0x03ad2821 in v8::internal::FixedArrayBase::length ()
  #1  0x03ad1dfc in v8::internal::FixedArray::get ()
  #2  0x03ae05dd in v8::internal::Context::global_object ()
  #3  0x03b6b87d in v8::internal::Context::builtins ()
  #4  0x03ae1871 in v8::internal::Isolate::js_builtins_object ()
  #5  0x03ab4fab in v8::CallV8HeapFunction ()
  #6  0x03ab4d4a in v8::Value::Equals ()
  #7  0x03b4f38b in CheckEqualsHelper ()
  #8  0x03ac0f4b in v8::Object::SetInternalField ()
  #9  0x06a99ddd in node::ObjectWrap::~ObjectWrap ()
  #10 0x06a8b051 in node::Buffer::~Buffer ()
  #11 0x06a8afbb in node::Buffer::~Buffer ()
  #12 0x06a8af5e in node::Buffer::~Buffer ()
  #13 0x06a9e569 in node::ObjectWrap::WeakCallback ()
2013-04-10 15:37:30 +02:00

127 lines
3.7 KiB
C++

// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.
#ifndef object_wrap_h
#define object_wrap_h
#include "node.h"
#include "v8.h"
#include <assert.h>
// Explicitly instantiate some template classes, so we're sure they will be
// present in the binary / shared object. There isn't much doubt that they will
// be, but MSVC tends to complain about these things.
#ifdef _MSC_VER
template class NODE_EXTERN v8::Persistent<v8::Object>;
template class NODE_EXTERN v8::Persistent<v8::FunctionTemplate>;
#endif
namespace node {
class NODE_EXTERN ObjectWrap {
public:
ObjectWrap ( ) {
refs_ = 0;
}
virtual ~ObjectWrap ( ) {
if (!handle_.IsEmpty()) {
assert(handle_.IsNearDeath());
handle_.ClearWeak();
handle_->SetPointerInInternalField(0, 0);
handle_.Dispose();
handle_.Clear();
}
}
template <class T>
static inline T* Unwrap (v8::Handle<v8::Object> handle) {
assert(!handle.IsEmpty());
assert(handle->InternalFieldCount() > 0);
return static_cast<T*>(handle->GetPointerFromInternalField(0));
}
v8::Persistent<v8::Object> handle_; // ro
protected:
inline void Wrap (v8::Handle<v8::Object> handle) {
assert(handle_.IsEmpty());
assert(handle->InternalFieldCount() > 0);
handle_ = v8::Persistent<v8::Object>::New(handle);
handle_->SetPointerInInternalField(0, this);
MakeWeak();
}
inline void MakeWeak (void) {
handle_.MakeWeak(this, WeakCallback);
handle_.MarkIndependent();
}
/* Ref() marks the object as being attached to an event loop.
* Refed objects will not be garbage collected, even if
* all references are lost.
*/
virtual void Ref() {
assert(!handle_.IsEmpty());
refs_++;
handle_.ClearWeak();
}
/* Unref() marks an object as detached from the event loop. This is its
* default state. When an object with a "weak" reference changes from
* attached to detached state it will be freed. Be careful not to access
* the object after making this call as it might be gone!
* (A "weak reference" means an object that only has a
* persistant handle.)
*
* DO NOT CALL THIS FROM DESTRUCTOR
*/
virtual void Unref() {
assert(!handle_.IsEmpty());
assert(!handle_.IsWeak());
assert(refs_ > 0);
if (--refs_ == 0) { MakeWeak(); }
}
int refs_; // ro
private:
static void WeakCallback (v8::Persistent<v8::Value> value, void *data) {
v8::HandleScope scope;
ObjectWrap *obj = static_cast<ObjectWrap*>(data);
assert(value == obj->handle_);
assert(!obj->refs_);
assert(value.IsNearDeath());
delete obj;
}
};
} // namespace node
#endif // object_wrap_h