From e440e47e91a93ae57870da8753f9c141c4a37885 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20v=2E=20L=C3=B6wis?= <martin@v.loewis.de>
Date: Tue, 1 Jun 2004 15:22:42 +0000
Subject: Patch #957398: Add public API for Generator Object/Type.
---
Doc/api/concrete.tex | 31 +++++++++++
Include/ceval.h | 1 +
Include/genobject.h | 33 ++++++++++++
Makefile.pre.in | 2 +
Misc/NEWS | 3 ++
Objects/genobject.c | 129 +++++++++++++++++++++++++++++++++++++++++++++
Python/ceval.c | 146 +++------------------------------------------------
7 files changed, 207 insertions(+), 138 deletions(-)
create mode 100644 Include/genobject.h
create mode 100644 Objects/genobject.c
diff --git a/Doc/api/concrete.tex b/Doc/api/concrete.tex
index e602528..62084bd 100644
--- a/Doc/api/concrete.tex
+++ b/Doc/api/concrete.tex
@@ -2603,3 +2603,34 @@ when accessed. Cell objects are not likely to be useful elsewhere.
reference counts are adjusted, and no checks are made for safety;
\var{cell} must be non-\NULL{} and must be a cell object.
\end{cfuncdesc}
+
+
+\subsection{Generator Objects \label{gen-objects}}
+
+Generator objects are what Python uses to implement generator iterators.
+They are normally created by iterating over a function that yields values,
+rather than explicitly calling \cfunction{PyGen_New}.
+
+\begin{ctypedesc}{PyGenObject}
+ The C structure used for generator objects.
+\end{ctypedesc}
+
+\begin{cvardesc}{PyTypeObject}{PyGen_Type}
+ The type object corresponding to generator objects
+\end{cvardesc}
+
+\begin{cfuncdesc}{int}{PyGen_Check}{ob}
+ Return true if \var{ob} is a generator object; \var{ob} must not be
+ \NULL.
+\end{cfuncdesc}
+
+\begin{cfuncdesc}{int}{PyGen_CheckExact}{ob}
+ Return true if \var{ob}'s type is \var{PyGen_Type}
+ is a generator object; \var{ob} must not be
+ \NULL.
+\end{cfuncdesc}
+
+\begin{cfuncdesc}{PyObject*}{PyGen_New}{PyFrameObject *frame}
+ Create and return a new generator object based on the \var{frame} object.
+ The parameter must not be \NULL.
+\end{cfuncdesc}
diff --git a/Include/ceval.h b/Include/ceval.h
index dc3864b..ae6de3a 100644
--- a/Include/ceval.h
+++ b/Include/ceval.h
@@ -64,6 +64,7 @@ PyAPI_FUNC(char *) PyEval_GetFuncName(PyObject *);
PyAPI_FUNC(char *) PyEval_GetFuncDesc(PyObject *);
PyAPI_FUNC(PyObject *) PyEval_GetCallStats(PyObject *);
+PyAPI_FUNC(PyObject *) PyEval_EvaluateFrame(PyObject *);
/* this used to be handled on a per-thread basis - now just two globals */
PyAPI_DATA(volatile int) _Py_Ticker;
diff --git a/Include/genobject.h b/Include/genobject.h
new file mode 100644
index 0000000..c9b7c19
--- /dev/null
+++ b/Include/genobject.h
@@ -0,0 +1,33 @@
+
+/* Generator object interface */
+
+#ifndef Py_GENOBJECT_H
+#define Py_GENOBJECT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+ PyObject_HEAD
+ /* The gi_ prefix is intended to remind of generator-iterator. */
+
+ PyFrameObject *gi_frame;
+
+ /* True if generator is being executed. */
+ int gi_running;
+
+ /* List of weak reference. */
+ PyObject *gi_weakreflist;
+} PyGenObject;
+
+PyAPI_DATA(PyTypeObject) PyGen_Type;
+
+#define PyGen_Check(op) PyObject_TypeCheck(op, &PyGen_Type)
+#define PyGen_CheckExact(op) ((op)->ob_type == &PyGen_Type)
+
+PyAPI_FUNC(PyObject *) PyGen_New(PyFrameObject *);
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_GENOBJECT_H */
diff --git a/Makefile.pre.in b/Makefile.pre.in
index 9a50039..074fba4 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -261,6 +261,7 @@ OBJECT_OBJS= \
Objects/complexobject.o \
Objects/descrobject.o \
Objects/enumobject.o \
+ Objects/genobject.o \
Objects/fileobject.o \
Objects/floatobject.o \
Objects/frameobject.o \
@@ -478,6 +479,7 @@ PYTHON_HEADERS= \
Include/descrobject.h \
Include/dictobject.h \
Include/enumobject.h \
+ Include/genobject.h \
Include/fileobject.h \
Include/floatobject.h \
Include/funcobject.h \
diff --git a/Misc/NEWS b/Misc/NEWS
index 2c5dfd9..33bfc43 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -497,6 +497,9 @@ Build
C API
-----
+- New public functions PyEval_EvaluateFrame and PyGen_New to expose
+ generator objects.
+
- New public functions Py_IncRef() and Py_DecRef(), exposing the
functionality of the Py_XINCREF() and Py_XDECREF macros. Useful for
runtime dynamic embedding of Python. See patch #938302, by Bob
diff --git a/Objects/genobject.c b/Objects/genobject.c
new file mode 100644
index 0000000..0f7373a
--- /dev/null
+++ b/Objects/genobject.c
@@ -0,0 +1,129 @@
+/* Generator object implementation */
+
+#include "Python.h"
+#include "frameobject.h"
+#include "genobject.h"
+#include "ceval.h"
+#include "structmember.h"
+
+static int
+gen_traverse(PyGenObject *gen, visitproc visit, void *arg)
+{
+ return visit((PyObject *)gen->gi_frame, arg);
+}
+
+static void
+gen_dealloc(PyGenObject *gen)
+{
+ _PyObject_GC_UNTRACK(gen);
+ if (gen->gi_weakreflist != NULL)
+ PyObject_ClearWeakRefs((PyObject *) gen);
+ Py_DECREF(gen->gi_frame);
+ PyObject_GC_Del(gen);
+}
+
+static PyObject *
+gen_iternext(PyGenObject *gen)
+{
+ PyThreadState *tstate = PyThreadState_GET();
+ PyFrameObject *f = gen->gi_frame;
+ PyObject *result;
+
+ if (gen->gi_running) {
+ PyErr_SetString(PyExc_ValueError,
+ "generator already executing");
+ return NULL;
+ }
+ if (f->f_stacktop == NULL)
+ return NULL;
+
+ /* Generators always return to their most recent caller, not
+ * necessarily their creator. */
+ Py_XINCREF(tstate->frame);
+ assert(f->f_back == NULL);
+ f->f_back = tstate->frame;
+
+ gen->gi_running = 1;
+ result = PyEval_EvaluateFrame((PyObject *)f);
+ gen->gi_running = 0;
+
+ /* Don't keep the reference to f_back any longer than necessary. It
+ * may keep a chain of frames alive or it could create a reference
+ * cycle. */
+ Py_XDECREF(f->f_back);
+ f->f_back = NULL;
+
+ /* If the generator just returned (as opposed to yielding), signal
+ * that the generator is exhausted. */
+ if (result == Py_None && f->f_stacktop == NULL) {
+ Py_DECREF(result);
+ result = NULL;
+ }
+
+ return result;
+}
+
+static PyObject *
+gen_getiter(PyObject *gen)
+{
+ Py_INCREF(gen);
+ return gen;
+}
+
+static PyMemberDef gen_memberlist[] = {
+ {"gi_frame", T_OBJECT, offsetof(PyGenObject, gi_frame), RO},
+ {"gi_running", T_INT, offsetof(PyGenObject, gi_running), RO},
+ {NULL} /* Sentinel */
+};
+
+PyTypeObject PyGen_Type = {
+ PyObject_HEAD_INIT(&PyType_Type)
+ 0, /* ob_size */
+ "generator", /* tp_name */
+ sizeof(PyGenObject), /* tp_basicsize */
+ 0, /* tp_itemsize */
+ /* methods */
+ (destructor)gen_dealloc, /* tp_dealloc */
+ 0, /* tp_print */
+ 0, /* tp_getattr */
+ 0, /* tp_setattr */
+ 0, /* tp_compare */
+ 0, /* tp_repr */
+ 0, /* tp_as_number */
+ 0, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ 0, /* tp_call */
+ 0, /* tp_str */
+ PyObject_GenericGetAttr, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
+ 0, /* tp_doc */
+ (traverseproc)gen_traverse, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ offsetof(PyGenObject, gi_weakreflist), /* tp_weaklistoffset */
+ (getiterfunc)gen_getiter, /* tp_iter */
+ (iternextfunc)gen_iternext, /* tp_iternext */
+ 0, /* tp_methods */
+ gen_memberlist, /* tp_members */
+ 0, /* tp_getset */
+ 0, /* tp_base */
+ 0, /* tp_dict */
+};
+
+PyObject *
+PyGen_New(PyFrameObject *f)
+{
+ PyGenObject *gen = PyObject_GC_New(PyGenObject, &PyGen_Type);
+ if (gen == NULL) {
+ Py_DECREF(f);
+ return NULL;
+ }
+ gen->gi_frame = f;
+ gen->gi_running = 0;
+ gen->gi_weakreflist = NULL;
+ _PyObject_GC_TRACK(gen);
+ return (PyObject *)gen;
+}
diff --git a/Python/ceval.c b/Python/ceval.c
index c103f14..2cebf44 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -10,6 +10,7 @@
#include "compile.h"
#include "frameobject.h"
+#include "genobject.h"
#include "eval.h"
#include "opcode.h"
#include "structmember.h"
@@ -139,143 +140,6 @@ PyEval_GetCallStats(PyObject *self)
}
#endif
-static PyTypeObject gentype;
-
-typedef struct {
- PyObject_HEAD
- /* The gi_ prefix is intended to remind of generator-iterator. */
-
- PyFrameObject *gi_frame;
-
- /* True if generator is being executed. */
- int gi_running;
-
- /* List of weak reference. */
- PyObject *gi_weakreflist;
-} genobject;
-
-static PyObject *
-gen_new(PyFrameObject *f)
-{
- genobject *gen = PyObject_GC_New(genobject, &gentype);
- if (gen == NULL) {
- Py_DECREF(f);
- return NULL;
- }
- gen->gi_frame = f;
- gen->gi_running = 0;
- gen->gi_weakreflist = NULL;
- _PyObject_GC_TRACK(gen);
- return (PyObject *)gen;
-}
-
-static int
-gen_traverse(genobject *gen, visitproc visit, void *arg)
-{
- return visit((PyObject *)gen->gi_frame, arg);
-}
-
-static void
-gen_dealloc(genobject *gen)
-{
- _PyObject_GC_UNTRACK(gen);
- if (gen->gi_weakreflist != NULL)
- PyObject_ClearWeakRefs((PyObject *) gen);
- Py_DECREF(gen->gi_frame);
- PyObject_GC_Del(gen);
-}
-
-static PyObject *
-gen_iternext(genobject *gen)
-{
- PyThreadState *tstate = PyThreadState_GET();
- PyFrameObject *f = gen->gi_frame;
- PyObject *result;
-
- if (gen->gi_running) {
- PyErr_SetString(PyExc_ValueError,
- "generator already executing");
- return NULL;
- }
- if (f->f_stacktop == NULL)
- return NULL;
-
- /* Generators always return to their most recent caller, not
- * necessarily their creator. */
- Py_XINCREF(tstate->frame);
- assert(f->f_back == NULL);
- f->f_back = tstate->frame;
-
- gen->gi_running = 1;
- result = eval_frame(f);
- gen->gi_running = 0;
-
- /* Don't keep the reference to f_back any longer than necessary. It
- * may keep a chain of frames alive or it could create a reference
- * cycle. */
- Py_XDECREF(f->f_back);
- f->f_back = NULL;
-
- /* If the generator just returned (as opposed to yielding), signal
- * that the generator is exhausted. */
- if (result == Py_None && f->f_stacktop == NULL) {
- Py_DECREF(result);
- result = NULL;
- }
-
- return result;
-}
-
-static PyObject *
-gen_getiter(PyObject *gen)
-{
- Py_INCREF(gen);
- return gen;
-}
-
-static PyMemberDef gen_memberlist[] = {
- {"gi_frame", T_OBJECT, offsetof(genobject, gi_frame), RO},
- {"gi_running", T_INT, offsetof(genobject, gi_running), RO},
- {NULL} /* Sentinel */
-};
-
-static PyTypeObject gentype = {
- PyObject_HEAD_INIT(&PyType_Type)
- 0, /* ob_size */
- "generator", /* tp_name */
- sizeof(genobject), /* tp_basicsize */
- 0, /* tp_itemsize */
- /* methods */
- (destructor)gen_dealloc, /* tp_dealloc */
- 0, /* tp_print */
- 0, /* tp_getattr */
- 0, /* tp_setattr */
- 0, /* tp_compare */
- 0, /* tp_repr */
- 0, /* tp_as_number */
- 0, /* tp_as_sequence */
- 0, /* tp_as_mapping */
- 0, /* tp_hash */
- 0, /* tp_call */
- 0, /* tp_str */
- PyObject_GenericGetAttr, /* tp_getattro */
- 0, /* tp_setattro */
- 0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
- 0, /* tp_doc */
- (traverseproc)gen_traverse, /* tp_traverse */
- 0, /* tp_clear */
- 0, /* tp_richcompare */
- offsetof(genobject, gi_weakreflist), /* tp_weaklistoffset */
- (getiterfunc)gen_getiter, /* tp_iter */
- (iternextfunc)gen_iternext, /* tp_iternext */
- 0, /* tp_methods */
- gen_memberlist, /* tp_members */
- 0, /* tp_getset */
- 0, /* tp_base */
- 0, /* tp_dict */
-};
-
#ifdef WITH_THREAD
@@ -2673,7 +2537,7 @@ PyEval_EvalCodeEx(PyCodeObject *co, PyObject *globals, PyObject *locals,
/* Create a new generator that owns the ready to run frame
* and return that as the value. */
- return gen_new(f);
+ return PyGen_New(f);
}
retval = eval_frame(f);
@@ -3407,6 +3271,12 @@ PyEval_GetFuncDesc(PyObject *func)
}
}
+PyObject *
+PyEval_EvaluateFrame(PyObject *fo)
+{
+ return eval_frame((PyFrameObject *)fo);
+}
+
#define EXT_POP(STACK_POINTER) (*--(STACK_POINTER))
static void
--
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