diff options
author | Campbell Barton <ideasman42@gmail.com> | 2009-04-19 16:46:39 +0400 |
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committer | Campbell Barton <ideasman42@gmail.com> | 2009-04-19 16:46:39 +0400 |
commit | 8d2cb5bea44f4245dd17f2d82cbd0251d8090fd5 (patch) | |
tree | b28e45f1edaf083c15d2176079836a4497685e57 /source/gameengine/Expressions/PyObjectPlus.cpp | |
parent | 92cea7c1b1540d11ed9729bacfabd23ccb7a79c7 (diff) |
BGE Python API
This changes how the BGE classes and Python work together, which hasnt changed since blender went opensource.
The main difference is PyObjectPlus - the base class for most game engine classes, no longer inherit from PyObject, and cannot be cast to a PyObject.
This has the advantage that the BGE does not have to keep 2 reference counts valid for C++ and Python.
Previously C++ classes would never be freed while python held a reference, however this reference could be problematic eg: a GameObject that isnt in a scene anymore should not be used by python, doing so could even crash blender in some cases.
Instead PyObjectPlus has a member "PyObject *m_proxy" which is lazily initialized when python needs it. m_proxy reference counts are managed by python, though it should never be freed while the C++ class exists since it holds a reference to avoid making and freeing it all the time.
When the C++ class is free'd it sets the m_proxy reference to NULL, If python accesses this variable it will raise a RuntimeError, (check the isValid attribute to see if its valid without raising an error).
- This replaces the m_zombie bool and IsZombie() tests added recently.
In python return values that used to be..
return value->AddRef();
Are now
return value->GetProxy();
or...
return value->NewProxy(true); // true means python owns this C++ value which will be deleted when the PyObject is freed
Diffstat (limited to 'source/gameengine/Expressions/PyObjectPlus.cpp')
-rw-r--r-- | source/gameengine/Expressions/PyObjectPlus.cpp | 69 |
1 files changed, 62 insertions, 7 deletions
diff --git a/source/gameengine/Expressions/PyObjectPlus.cpp b/source/gameengine/Expressions/PyObjectPlus.cpp index 0db2e8991fc..2c5ba3f39fc 100644 --- a/source/gameengine/Expressions/PyObjectPlus.cpp +++ b/source/gameengine/Expressions/PyObjectPlus.cpp @@ -54,6 +54,7 @@ * PyObjectPlus Type -- Every class, even the abstract one should have a Type ------------------------------*/ + PyTypeObject PyObjectPlus::Type = { PyObject_HEAD_INIT(NULL) 0, /*ob_size*/ @@ -74,21 +75,33 @@ PyTypeObject PyObjectPlus::Type = { Methods }; + PyObjectPlus::~PyObjectPlus() { - if (ob_refcnt) - { - _Py_ForgetReference(this); + if(m_proxy) { + Py_DECREF(m_proxy); /* Remove own reference, python may still have 1 */ + BGE_PROXY_REF(m_proxy)= NULL; } // assert(ob_refcnt==0); } +void PyObjectPlus::PyDestructor(PyObject *self) // python wrapper +{ + PyObjectPlus *self_plus= BGE_PROXY_REF(self); + if(self_plus) { + if(BGE_PROXY_PYOWNS(self)) { /* Does python own this?, then delete it */ + delete self_plus; + } + + BGE_PROXY_REF(self)= NULL; // not really needed + } + PyObject_DEL( self ); +}; + PyObjectPlus::PyObjectPlus(PyTypeObject *T) // constructor { MT_assert(T != NULL); - this->ob_type = T; - _Py_NewReference(this); - SetZombie(false); + m_proxy= NULL; }; /*------------------------------ @@ -131,7 +144,7 @@ PyObject *PyObjectPlus::py_getattro(PyObject* attr) if (PyCObject_Check(descr)) { return py_get_attrdef((void *)this, (const PyAttributeDef*)PyCObject_AsVoidPtr(descr)); } else if (descr->ob_type->tp_descr_get) { - return PyCFunction_New(((PyMethodDescrObject *)descr)->d_method, (PyObject *)this); + return PyCFunction_New(((PyMethodDescrObject *)descr)->d_method, this->m_proxy); } else { fprintf(stderr, "Unknown attribute type (PyObjectPlus::py_getattro)"); return descr; @@ -794,5 +807,47 @@ PyObject *py_getattr_dict(PyObject *pydict, PyObject *tp_dict) return pydict; } + + +PyObject *PyObjectPlus::GetProxy_Ext(PyObjectPlus *self, PyTypeObject *tp) +{ + if (self->m_proxy==NULL) + { + self->m_proxy = reinterpret_cast<PyObject *>PyObject_NEW( PyObjectPlus_Proxy, tp); + BGE_PROXY_PYOWNS(self->m_proxy) = false; + } + //PyObject_Print(self->m_proxy, stdout, 0); + //printf("ref %d\n", self->m_proxy->ob_refcnt); + + BGE_PROXY_REF(self->m_proxy) = self; /* Its possible this was set to NULL, so set it back here */ + Py_INCREF(self->m_proxy); /* we own one, thos ones fore the return */ + return self->m_proxy; +} + +PyObject *PyObjectPlus::NewProxy_Ext(PyObjectPlus *self, PyTypeObject *tp, bool py_owns) +{ + if (self->m_proxy) + { + if(py_owns) + { /* Free */ + BGE_PROXY_REF(self->m_proxy) = NULL; + Py_DECREF(self->m_proxy); + self->m_proxy= NULL; + } + else { + Py_INCREF(self->m_proxy); + return self->m_proxy; + } + + } + + GetProxy_Ext(self, tp); + if(py_owns) { + BGE_PROXY_PYOWNS(self->m_proxy) = py_owns; + Py_DECREF(self->m_proxy); /* could avoid thrashing here but for now its ok */ + } + return self->m_proxy; +} + #endif //NO_EXP_PYTHON_EMBEDDING |