/* The PyObject_ memory family: high-level object memory interfaces.
See pymem.h for the low-level PyMem_ family.
*/
#ifndef Py_OBJIMPL_H
#define Py_OBJIMPL_H
#include "pymem.h"
#ifdef __cplusplus
extern "C" {
#endif
/* BEWARE:
Each interface exports both functions and macros. Extension modules should
use the functions, to ensure binary compatibility across Python versions.
Because the Python implementation is free to change internal details, and
the macros may (or may not) expose details for speed, if you do use the
macros you must recompile your extensions with each Python release.
Never mix calls to PyObject_ memory functions with calls to the platform
malloc/realloc/ calloc/free, or with calls to PyMem_.
*/
/*
Functions and macros for modules that implement new object types.
- PyObject_New(type, typeobj) allocates memory for a new object of the given
type, and initializes part of it. 'type' must be the C structure type used
to represent the object, and 'typeobj' the address of the corresponding
type object. Reference count and type pointer are filled in; the rest of
the bytes of the object are *undefined*! The resulting expression type is
'type *'. The size of the object is determined by the tp_basicsize field
of the type object.
- PyObject_NewVar(type, typeobj, n) is similar but allocates a variable-size
object with room for n items. In addition to the refcount and type pointer
fields, this also fills in the ob_size field.
- PyObject_Del(op) releases the memory allocated for an object. It does not
run a destructor -- it only frees the memory. PyObject_Free is identical.
- PyObject_Init(op, typeobj) and PyObject_InitVar(op, typeobj, n) don't
allocate memory. Instead of a 'type' parameter, they take a pointer to a
new object (allocated by an arbitrary allocator), and initialize its object
header fields.
Note that objects created with PyObject_{New, NewVar} are allocated using the
specialized Python allocator (implemented in obmalloc.c), if WITH_PYMALLOC is
enabled. In addition, a special debugging allocator is used if PYMALLOC_DEBUG
is also #defined.
In case a specific form of memory management is needed (for example, if you
must use the platform malloc heap(s), or shared memory, or C++ local storage or
operator new), you must first allocate the object with your custom allocator,
then pass its pointer to PyObject_{Init, InitVar} for filling in its Python-
specific fields: reference count, type pointer, possibly others. You should
be aware that Python no control over these objects because they don't
cooperate with the Python memory manager. Such objects may not be eligible
for automatic garbage collection and you have to make sure that they are
released accordingly whenever their destructor gets called (cf. the specific
form of memory management you're using).
Unless you have specific memory management requirements, use
PyObject_{New, NewVar, Del}.
*/
/*
* Raw object memory interface
* ===========================
*/
/* Functions to call the same malloc/realloc/free as used by Python's
object allocator. If WITH_PYMALLOC is enabled, these may differ from
the platform malloc/realloc/free. The Python object allocator is
designed for fast, cache-conscious allocation of many "small" objects,
and with low hidden memory overhead.
PyObject_Malloc(0) returns a unique non-NULL pointer if possible.
PyObject_Realloc(NULL, n) acts like PyObject_Malloc(n).
PyObject_Realloc(p != NULL, 0) does not return NULL, or free the memory
at p.
Returned pointers must be checked for NULL explicitly; no action is
performed on failure other than to return NULL (no warning it printed, no
exception is set, etc).
For allocating objects, use PyObject_{New, NewVar} instead whenever
possible. The PyObject_{Malloc, Realloc, Free} family is exposed
so that you can exploit Python's small-block allocator for non-object
uses. If you must use these routines to allocate object memory, make sure
the object gets initialized via PyObject_{Init, InitVar} after obtaining
the raw memory.
*/
PyAPI_FUNC(void *) PyObject_Malloc(size_t);
PyAPI_FUNC(void *) PyObject_Realloc(void *, size_t);
PyAPI_FUNC(void) PyObject_Free(void *);
/* Macros */
#ifdef WITH_PYMALLOC
PyAPI_FUNC(void) _PyObject_DebugMallocStats(FILE *out);
#ifdef PYMALLOC_DEBUG /* WITH_PYMALLOC && PYMALLOC_DEBUG */
PyAPI_FUNC(void *) _PyObject_DebugMalloc(size_t nbytes);
PyAPI_FUNC(void *) _PyObject_DebugRealloc(void *p, size_t nbytes);
PyAPI_FUNC(void) _PyObject_DebugFree(void *p);
PyAPI_FUNC(void) _PyObject_DebugDumpAddress(const void *p);
PyAPI_FUNC(void) _PyObject_DebugCheckAddress(const void *p);
PyAPI_FUNC(void *) _PyObject_DebugMallocApi(char api, size_t nbytes);
PyAPI_FUNC(void *) _PyObject_DebugReallocApi(char api, void *p, size_t nbytes);
PyAPI_FUNC(void) _PyObject_DebugFreeApi(char api, void *p);
PyAPI_FUNC(void) _PyObject_DebugCheckAddressApi(char api, const void *p);
PyAPI_FUNC(void *) _PyMem_DebugMalloc(size_t nbytes);
PyAPI_FUNC(void *) _PyMem_DebugRealloc(void *p, size_t nbytes);
PyAPI_FUNC(void) _PyMem_DebugFree(void *p);
#define PyObject_MALLOC _PyObject_DebugMalloc
#define PyObject_Malloc _PyObject_DebugMalloc
#define PyObject_REALLOC _PyObject_DebugRealloc
#define PyObject_Realloc _PyObject_DebugRealloc
#define PyObject_FREE _PyObject_DebugFree
#define PyObject_Free _PyObject_DebugFree
#else /* WITH_PYMALLOC && ! PYMALLOC_DEBUG */
#define PyObject_MALLOC PyObject_Malloc
#define PyObject_REALLOC PyObject_Realloc
#define PyObject_FREE PyObject_Free
#endif
#else /* ! WITH_PYMALLOC */
#define PyObject_MALLOC PyMem_MALLOC
#define PyObject_REALLOC PyMem_REALLOC
#define PyObject_FREE PyMem_FREE
#endif /* WITH_PYMALLOC */
#define PyObject_Del PyObject_Free
#define PyObject_DEL PyObject_FREE
/* for source compatibility with 2.2 */
#define _PyObject_Del PyObject_Free
/*
* Generic object allocator interface
* ==================================
*/
/* Functions */
PyAPI_FUNC(PyObject *) PyObject_Init(PyObject *, PyTypeObject *);
PyAPI_FUNC(PyVarObject *) PyObject_InitVar(PyVarObject *,
PyTypeObject *, Py_ssize_t);
PyAPI_FUNC(PyObject *) _PyObject_New(PyTypeObject *);
PyAPI_FUNC(PyVarObject *) _PyObject_NewVar(PyTypeObject *, Py_ssize_t);
#define PyObject_New(type, typeobj) \
( (type *) _PyObject_New(typeobj) )
#define PyObject_NewVar(type, typeobj, n) \
( (type *) _PyObject_NewVar((typeobj), (n)) )
/* Macros trading binary compatibility for speed. See also pymem.h.
Note that these macros expect non-NULL object pointers.*/
#define PyObject_INIT(op, typeobj) \
( Py_TYPE(op) = (typeobj), _Py_NewReference((PyObject *)(op)), (op) )
#define PyObject_INIT_VAR(op, typeobj, size) \
( Py_SIZE(op) = (size), PyObject_INIT((op), (typeobj)) )
#define _PyObject_SIZE(typeobj) ( (typeobj)->tp_basicsize )
/* _PyObject_VAR_SIZE returns the number of bytes (as size_t) allocated for a
vrbl-size object with nitems items, exclusive of gc overhead (if any). The
value is rounded up to the closest multiple of sizeof(void *), in order to
ensure that pointer fields at the end of the object are correctly aligned
for the platform (this is of special importance for subclasses of, e.g.,
str or long, so that pointers can be stored after the embedded data).
Note that there's no memory wastage in doing this, as malloc has to
return (at worst) pointer-aligned memory anyway.
*/
#if ((SIZEOF_VOID_P - 1) & SIZEOF_VOID_P) != 0
# error "_PyObject_VAR_SIZE requires SIZEOF_VOID_P be a power of 2"
#endif
#define _PyObject_VAR_SIZE(typeobj, nitems) \
(size_t) \
( ( (typeobj)->tp_basicsize + \
(nitems)*(typeobj)->tp_itemsize + \
(SIZEOF_VOID_P - 1) \
) & ~(SIZEOF_VOID_P - 1) \
)
#define PyObject_NEW(type, typeobj) \
( (type *) PyObject_Init( \
(PyObject *) PyObject_MALLOC( _PyObject_SIZE(typeobj) ), (typeobj)) )
#define PyObject_NEW_VAR(type, typeobj, n) \
( (type *) PyObject_InitVar( \
(PyVarObject *) PyObject_MALLOC(_PyObject_VAR_SIZE((typeobj),(n)) ),\
(typeobj), (n)) )
/* This example code implements an object constructor with a custom
allocator, where PyObject_New is inlined, and shows the important
distinction between two steps (at least):
1) the actual allocation of the object storage;
2) the initialization of the Python specific fields
in this storage with PyObject_{Init, InitVar}.
PyObject *
YourObject_New(...)
{
PyObject *op;
op = (PyObject *) Your_Allocator(_PyObject_SIZE(YourTypeStruct));
if (op == NULL)
return PyErr_NoMemory();
PyObject_Init(op, &YourTypeStruct);
op->ob_field = value;
...
return op;
}
Note that in C++, the use of the new operator usually implies that
the 1st step is performed automatically for you, so in a C++ class
constructor you would start directly with PyObject_Init/InitVar
*/
/*
* Garbage Collection Support
* ==========================
*/
/* C equivalent of gc.collect(). */
PyAPI_FUNC(Py_ssize_t) PyGC_Collect(void);
/* Test if a type has a GC head */
#define PyType_IS_GC(t) PyType_HasFeature((t), Py_TPFLAGS_HAVE_GC)
/* Test if an object has a GC head */
#define PyObject_IS_GC(o) (PyType_IS_GC(Py_TYPE(o)) && \
(Py_TYPE(o)->tp_is_gc == NULL || Py_TYPE(o)->tp_is_gc(o)))
PyAPI_FUNC(PyVarObject *) _PyObject_GC_Resize(PyVarObject *, Py_ssize_t);
#define PyObject_GC_Resize(type, op, n) \
( (type *) _PyObject_GC_Resize((PyVarObject *)(op), (n)) )
/* for source compatibility with 2.2 */
#define _PyObject_GC_Del PyObject_GC_Del
/* GC information is stored BEFORE the object structure. */
typedef union _gc_head {
struct {
union _gc_head *gc_next;
union _gc_head *gc_prev;
Py_ssize_t gc_refs;
} gc;
long double dummy; /* force worst-case alignment */
} PyGC_Head;
extern PyGC_Head *_PyGC_generation0;
#define _Py_AS_GC(o) ((PyGC_Head *)(o)-1)
#define _PyGC_REFS_UNTRACKED (-2)
#define _PyGC_REFS_REACHABLE (-3)
#define _PyGC_REFS_TENTATIVELY_UNREACHABLE (-4)
/* Tell the GC to track this object. NB: While the object is tracked the
* collector it must be safe to call the ob_traverse method. */
#define _PyObject_GC_TRACK(o) do { \
PyGC_Head *g = _Py_AS_GC(o); \
if (g->gc.gc_refs != _PyGC_REFS_UNTRACKED) \
Py_FatalError("GC object already tracked"); \
g->gc.gc_refs = _PyGC_REFS_REACHABLE; \
g->gc.gc_next = _PyGC_generation0; \
g->gc.gc_prev = _PyGC_generation0->gc.gc_prev; \
g->gc.gc_prev->gc.gc_next = g; \
_PyGC_generation0->gc.gc_prev = g; \
} while (0);
/* Tell the GC to stop tracking this object.
* gc_next doesn't need to be set to NULL, but doing so is a good
* way to provoke memory errors if calling code is confused.
*/
#define _PyObject_GC_UNTRACK(o) do { \
PyGC_Head *g = _Py_AS_GC(o); \
assert(g->gc.gc_refs != _PyGC_REFS_UNTRACKED); \
g->gc.gc_refs = _PyGC_REFS_UNTRACKED; \
g->gc.gc_prev->gc.gc_next = g->gc.gc_next; \
g->gc.gc_next->gc.gc_prev = g->gc.gc_prev; \
g->gc.gc_next = NULL; \
} while (0);
/* True if the object is currently tracked by the GC. */
#define _PyObject_GC_IS_TRACKED(o) \
((_Py_AS_GC(o))->gc.gc_refs != _PyGC_REFS_UNTRACKED)
/* True if the object may be tracked by the GC in the future, or already is.
This can be useful to implement some optimizations. */
#define _PyObject_GC_MAY_BE_TRACKED(obj) \
(PyObject_IS_GC(obj) && \
(!PyTuple_CheckExact(obj) || _PyObject_GC_IS_TRACKED(obj)))
PyAPI_FUNC(PyObject *) _PyObject_GC_Malloc(size_t);
PyAPI_FUNC(PyObject *) _PyObject_GC_New(PyTypeObject *);
PyAPI_FUNC(PyVarObject *) _PyObject_GC_NewVar(PyTypeObject *, Py_ssize_t);
PyAPI_FUNC(void) PyObject_GC_Track(void *);
PyAPI_FUNC(void) PyObject_GC_UnTrack(void *);
PyAPI_FUNC(void) PyObject_GC_Del(void *);
#define PyObject_GC_New(type, typeobj) \
( (type *) _PyObject_GC_New(typeobj) )
#define PyObject_GC_NewVar(type, typeobj, n) \
( (type *) _PyObject_GC_NewVar((typeobj), (n)) )
/* Utility macro to help write tp_traverse functions.
* To use this macro, the tp_traverse function must name its arguments
* "visit" and "arg". This is intended to keep tp_traverse functions
* looking as much alike as possible.
*/
#define Py_VISIT(op) \
do { \
if (op) { \
int vret = visit((PyObject *)(op), arg); \
if (vret) \
return vret; \
} \
} while (0)
/* This is here for the sake of backwards compatibility. Extensions that
* use the old GC API will still compile but the objects will not be
* tracked by the GC. */
#define PyGC_HEAD_SIZE 0
#define PyObject_GC_Init(op)
#define PyObject_GC_Fini(op)
#define PyObject_AS_GC(op) (op)
#define PyObject_FROM_GC(op) (op)
/* Test if a type supports weak references */
#define PyType_SUPPORTS_WEAKREFS(t) \
(PyType_HasFeature((t), Py_TPFLAGS_HAVE_WEAKREFS) \
&& ((t)->tp_weaklistoffset > 0))
#define PyObject_GET_WEAKREFS_LISTPTR(o) \
((PyObject **) (((char *) (o)) + Py_TYPE(o)->tp_weaklistoffset))
#ifdef __cplusplus
}
#endif
#endif /* !Py_OBJIMPL_H */
Rosenblum TV: Video training, virtual workshops, classes, tutorials
RE-INVENTING THE TELEVISION NEWS BUSINESS*
A revolution in video storytelling
Creating entirely new & cost-effective production methods
From the world leaders in video production training and the creators of Character Driven Storytelling™
*and every other business that uses video
WHAT WE DO
Over the past 35 years, we have designed, built or restructured some of the most powerful news and journalism companies in the world.
We replace the traditional TV news ‘crew’ with one highly trained journalist, working alone with nothing but an iPhone.
No more TV news ‘crews’, no editors and no field producers.
This is television news done the way newspaper journalism is done – one reporter with their electronic pad and pencil.
In doing this, we can cut the cost of production by as much as 75% while increasing ratings and audience engagement.
In the place of conventional TV news ‘packages’ – ie, reporter stand up, interview, b-roll, man on the street, we marry great journalism with Netflix and Hollywood storytelling.
It’s a combination that works.
We have taken most of our clients to #1 in their respective markets.
And it’s not just for news. Any company, any profit, any NGO and anyone else who is online needs to tell their story in compelling yet cost-effective video. We can teach you to do that. Either in person or virtually.
EXAMPLES OF WHAT WE CAN TEACH YOUR STAFF TO PRODUCE
ITAY HOD
Itay Hod, MMJ with KPIX/CBS in San Francisco, took the 5-Day Intensive Video Storytelling Bootcamp in 2018.
Because he works alone, with only an iPhone, he was able to embed himself with a homeless family.
Here’s the story he produced in a one-day turn.
KIET DO
Kiet Do, an MMJ with KPIX/CBS in San Francisco, took the 5-Day Intensive Video Storytelling Bootcamp in 2021.
Here is a story he produced, all on his own, with only an iPhone and in a one-day turn.
TAYLOR SCHAUB
Taylor Schaub, an MMJ with Spectrum News 1 in LA, took the 5-Day Intensive Video Storytelling Bootcamp in 2023.
Here is a story he turned in only one day, using only an iPhone. It was the first video story he ever did and it was nominated for an Emmy.
THE BOOTCAMP
How do we convert stations and whole networks to working in this way?
Since 1988, we have run intensive 5-Day Video Storytelling Bootcamps
We have done these all over the world.
These are hands-on bootcamps, and participants learn an entirely new way of creating TV news stories.
-We shoot at a 3:1 ratio or lower, so turnaround times are fast.
-We go directly from camera to timelilne and edit – no written scripts. We work in the medium of pictures and sound.
-We are entirely character-driven.
-We are driven by pictures and real events.
-We are focused almost entirely on ’the viewer experience’.
Since 1988, more than 70,000 journalists around the world have taken our bootcamps, either in person on virtualy.
We have started to work with CBS News, bringing our ideas of character-driven storytelling to one of the most successful and biggest networks in the United States. Since beginning to work with them ratings have climbed and more importantly, audience engagement is through the ceiling.
We started New York Times Television in 1990 and it was the first paper to be brought into the world of TV. It quickly became one of the most successful non-fiction production companies in the United States. The series and documentaries we produced won many awards including multiple Emmys.
We have been working with the BBC since the year 2000 helping to convert their national news network to our visual storytelling technique. Most recently we have trained teams from their sports, documentaries, and comedy divisions to make character-driven stories using only smartphones.
For the past five years we have worked with Spectrum News to introduce and train their journalists on visual, character driven storytelling using smartphones helping to create a different kind of local news for their network of 24-Hour News Stations across the United States.
In 2006, we were approached by the United Nations. Rather than rely on news outlets, it would be much easier to train the field operatives to produce their own stories. We spent two years working with the UN, training more than 100 of their staff in bootcamps in Geneva and Nairobi.
We trained 50 print reporters at the paper to shoot and tell their own stories, in conjunction with their print work. We built a TV newsroom in their existing print newsroom – you could not ask for a better set and they began to live stream their stories in conjunction with their print work.
We spent two years with McGraw Hill, training more than 150 of their staffers, making them completely video literate. McGraw/Hill media properties we transit included Business Week, Aviation Week, (what was the name of the architecture magazine), and JD Power and Associates.
In 1990, we were approached by The Voice of America, the official broadcasting agency for the United States Government. When we met with VOA, they were only a short wave radio broadcaster, but working with them, we took them into television, launching VOA-TV.
British based Oyster Yachts makes some of the finest yachts in the world. Like every other company, they had to find a way to feed the never-ending video demands of social media – sites like Instagram and TikTok. We trained the Oyster staff to tell their own stories, using only iPhones.
We were approached by SEPA, the Scottish Environmental Protection Agency because they had to continually find a way to ‘feed the media beast’. The result was that SEPA was able to tell their own stories, whenever they wanted, and at almost no additional cost.
Michael Rosenblum has been writing about the media since 1988. His work and ideas have appeared in The Guardian, The Huffington Post, Ilkeston Life and many other publications.
He has been blogging regularly for the past 35 years on this subject. Having taught media studies at Columbia University, NYU and now the University of Oxford, he is considered an expert on this subject.
Continue reading this post or look back at previous posts.