diff options
Diffstat (limited to 'Doc/api/api.tex')
| -rw-r--r-- | Doc/api/api.tex | 77 |
1 files changed, 48 insertions, 29 deletions
diff --git a/Doc/api/api.tex b/Doc/api/api.tex index 28ca2d0..8836cdf 100644 --- a/Doc/api/api.tex +++ b/Doc/api/api.tex @@ -5508,36 +5508,45 @@ references to atomic types (such as numbers or strings), do not need to provide any explicit support for garbage collection. To create a container type, the \member{tp_flags} field of the type -object must include the \constant{Py_TPFLAGS_GC} and provide an -implementation of the \member{tp_traverse} handler. The computed -value of the \member{tp_basicsize} field must include -\constant{PyGC_HEAD_SIZE} as well. If instances of the type are -mutable, a \member{tp_clear} implementation must also be provided. +object must include the \constant{Py_TPFLAGS_HAVE_GC} and provide an +implementation of the \member{tp_traverse} handler. If instances of the +type are mutable, a \member{tp_clear} implementation must also be +provided. -\begin{datadesc}{Py_TPFLAGS_GC} +\begin{datadesc}{Py_TPFLAGS_HAVE_GC} Objects with a type with this flag set must conform with the rules documented here. For convenience these objects will be referred to as container objects. \end{datadesc} -\begin{datadesc}{PyGC_HEAD_SIZE} - Extra memory needed for the garbage collector. Container objects - must include this in the calculation of their tp_basicsize. If the - collector is disabled at compile time then this is \code{0}. -\end{datadesc} - Constructors for container types must conform to two rules: \begin{enumerate} \item The memory for the object must be allocated using - \cfunction{PyObject_New()} or \cfunction{PyObject_VarNew()}. + \cfunction{PyObject_GC_New()} or \cfunction{PyObject_GC_VarNew()}. \item Once all the fields which may contain references to other containers are initialized, it must call - \cfunction{PyObject_GC_Init()}. + \cfunction{PyObject_GC_Track()}. \end{enumerate} -\begin{cfuncdesc}{void}{PyObject_GC_Init}{PyObject *op} +\begin{cfuncdesc}{\var{TYPE}*}{PyObject_GC_New}{TYPE, PyTypeObject *type} + Analogous to \cfunction{PyObject_New()} but for container objects with + the \constant{Py_TPFLAGS_HAVE_GC} flag set. +\end{cfuncdesc} + +\begin{cfuncdesc}{\var{TYPE}*}{PyObject_GC_NewVar}{TYPE, PyTypeObject *type, + int size} + Analogous to \cfunction{PyObject_NewVar()} but for container objects + with the \constant{Py_TPFLAGS_HAVE_GC} flag set. +\end{cfuncdesc} + +\begin{cfuncdesc}{PyVarObject *}{PyObject_GC_Resize}{PyVarObject *op, int} + Resize an object allocated by \cfunction{PyObject_NewVar()}. Returns + the resized object or \NULL{} on failure. +\end{cfuncdesc} + +\begin{cfuncdesc}{void}{PyObject_GC_Track}{PyObject *op} Adds the object \var{op} to the set of container objects tracked by the collector. The collector can run at unexpected times so objects must be valid while being tracked. This should be called once all @@ -5545,29 +5554,39 @@ Constructors for container types must conform to two rules: usually near the end of the constructor. \end{cfuncdesc} +\begin{cfuncdesc}{void}{_PyObject_GC_TRACK}{PyObject *op} + A macro version of \cfunction{PyObject_GC_Track()}. It should not be + used for extension modules. +\end{cfuncdesc} + Similarly, the deallocator for the object must conform to a similar pair of rules: \begin{enumerate} \item Before fields which refer to other containers are invalidated, - \cfunction{PyObject_GC_Fini()} must be called. + \cfunction{PyObject_GC_UnTrack()} must be called. \item The object's memory must be deallocated using - \cfunction{PyObject_Del()}. + \cfunction{PyObject_GC_Del()}. \end{enumerate} -\begin{cfuncdesc}{void}{PyObject_GC_Fini}{PyObject *op} +\begin{cfuncdesc}{void}{PyObject_GC_Del}{PyObject *op} + Releases memory allocated to an object using + \cfunction{PyObject_GC_New()} or \cfunction{PyObject_GC_NewVar()}. +\end{cfuncdesc} + +\begin{cfuncdesc}{void}{PyObject_GC_UnTrack}{PyObject *op} Remove the object \var{op} from the set of container objects tracked - by the collector. Note that \cfunction{PyObject_GC_Init()} can be + by the collector. Note that \cfunction{PyObject_GC_Track()} can be called again on this object to add it back to the set of tracked objects. The deallocator (\member{tp_dealloc} handler) should call this for the object before any of the fields used by the \member{tp_traverse} handler become invalid. +\end{cfuncdesc} - \strong{Note:} Any container which may be referenced from another - object reachable by the collector must itself be tracked by the - collector, so it is generally not safe to call this function - anywhere but in the object's deallocator. +\begin{cfuncdesc}{void}{_PyObject_GC_UNTRACK}{PyObject *op} + A macro version of \cfunction{PyObject_GC_UnTrack()}. It should not be + used for extension modules. \end{cfuncdesc} The \member{tp_traverse} handler accepts a function parameter of this @@ -5650,9 +5669,9 @@ my_clear(MyObject *self) static void my_dealloc(MyObject *self) { - PyObject_GC_Fini((PyObject *) self); + PyObject_GC_UnTrack((PyObject *) self); Py_XDECREF(self->container); - PyObject_Del(self); + PyObject_GC_Del(self); } \end{verbatim} @@ -5662,7 +5681,7 @@ MyObject_Type = { PyObject_HEAD_INIT(NULL) 0, "MyObject", - sizeof(MyObject) + PyGC_HEAD_SIZE, + sizeof(MyObject), 0, (destructor)my_dealloc, /* tp_dealloc */ 0, /* tp_print */ @@ -5679,7 +5698,7 @@ MyObject_Type = { 0, /* tp_getattro */ 0, /* tp_setattro */ 0, /* tp_as_buffer */ - Py_TPFLAGS_DEFAULT | Py_TPFLAGS_GC, + Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, 0, /* tp_doc */ (traverseproc)my_traverse, /* tp_traverse */ (inquiry)my_clear, /* tp_clear */ @@ -5695,10 +5714,10 @@ new_object(PyObject *unused, PyObject *args) MyObject *result = NULL; if (PyArg_ParseTuple(args, "|O:new_object", &container)) { - result = PyObject_New(MyObject, &MyObject_Type); + result = PyObject_GC_New(MyObject, &MyObject_Type); if (result != NULL) { result->container = container; - PyObject_GC_Init(); + PyObject_GC_Track(result); } } return (PyObject *) result; |