diff options
Diffstat (limited to 'Doc/c-api')
| -rw-r--r-- | Doc/c-api/arg.rst | 14 | ||||
| -rw-r--r-- | Doc/c-api/exceptions.rst | 8 | ||||
| -rw-r--r-- | Doc/c-api/import.rst | 8 | ||||
| -rw-r--r-- | Doc/c-api/init.rst | 33 | ||||
| -rw-r--r-- | Doc/c-api/intro.rst | 11 | ||||
| -rw-r--r-- | Doc/c-api/memory.rst | 113 | ||||
| -rw-r--r-- | Doc/c-api/structures.rst | 5 | ||||
| -rw-r--r-- | Doc/c-api/sys.rst | 25 |
8 files changed, 149 insertions, 68 deletions
diff --git a/Doc/c-api/arg.rst b/Doc/c-api/arg.rst index d5e4703..f932997 100644 --- a/Doc/c-api/arg.rst +++ b/Doc/c-api/arg.rst @@ -223,8 +223,7 @@ which disallows mutable objects such as :class:`bytearray`. :c:func:`PyArg_ParseTuple` will use this location as the buffer and interpret the initial value of *\*buffer_length* as the buffer size. It will then copy the encoded data into the buffer and NUL-terminate it. If the buffer is not large - enough, a :exc:`TypeError` will be set. - Note: starting from Python 3.6 a :exc:`ValueError` will be set. + enough, a :exc:`ValueError` will be set. In both cases, *\*buffer_length* is set to the length of the encoded data without the trailing NUL byte. @@ -424,8 +423,15 @@ API Functions .. c:function:: int PyArg_ParseTupleAndKeywords(PyObject *args, PyObject *kw, const char *format, char *keywords[], ...) Parse the parameters of a function that takes both positional and keyword - parameters into local variables. Returns true on success; on failure, it - returns false and raises the appropriate exception. + parameters into local variables. The *keywords* argument is a + *NULL*-terminated array of keyword parameter names. Empty names denote + :ref:`positional-only parameters <positional-only_parameter>`. + Returns true on success; on failure, it returns false and raises the + appropriate exception. + + .. versionchanged:: 3.6 + Added support for :ref:`positional-only parameters + <positional-only_parameter>`. .. c:function:: int PyArg_VaParseTupleAndKeywords(PyObject *args, PyObject *kw, const char *format, char *keywords[], va_list vargs) diff --git a/Doc/c-api/exceptions.rst b/Doc/c-api/exceptions.rst index 19cbb3b..226b619 100644 --- a/Doc/c-api/exceptions.rst +++ b/Doc/c-api/exceptions.rst @@ -334,6 +334,14 @@ an error value). .. versionadded:: 3.2 +.. c:function:: int PyErr_ResourceWarning(PyObject *source, Py_ssize_t stack_level, const char *format, ...) + + Function similar to :c:func:`PyErr_WarnFormat`, but *category* is + :exc:`ResourceWarning` and pass *source* to :func:`warnings.WarningMessage`. + + .. versionadded:: 3.6 + + Querying the error indicator ============================ diff --git a/Doc/c-api/import.rst b/Doc/c-api/import.rst index 2936f4f..5a083ce 100644 --- a/Doc/c-api/import.rst +++ b/Doc/c-api/import.rst @@ -207,13 +207,13 @@ Importing Modules .. c:function:: PyObject* PyImport_GetImporter(PyObject *path) - Return an importer object for a :data:`sys.path`/:attr:`pkg.__path__` item + Return a finder object for a :data:`sys.path`/:attr:`pkg.__path__` item *path*, possibly by fetching it from the :data:`sys.path_importer_cache` dict. If it wasn't yet cached, traverse :data:`sys.path_hooks` until a hook is found that can handle the path item. Return ``None`` if no hook could; - this tells our caller it should fall back to the built-in import mechanism. - Cache the result in :data:`sys.path_importer_cache`. Return a new reference - to the importer object. + this tells our caller that the :term:`path based finder` could not find a + finder for this path item. Cache the result in :data:`sys.path_importer_cache`. + Return a new reference to the finder object. .. c:function:: void _PyImport_Init() diff --git a/Doc/c-api/init.rst b/Doc/c-api/init.rst index 639819c..d77836a 100644 --- a/Doc/c-api/init.rst +++ b/Doc/c-api/init.rst @@ -25,7 +25,7 @@ Initializing and finalizing the interpreter triple: module; search; path single: PySys_SetArgv() single: PySys_SetArgvEx() - single: Py_Finalize() + single: Py_FinalizeEx() Initialize the Python interpreter. In an application embedding Python, this should be called before using any other Python/C API functions; with the @@ -34,7 +34,7 @@ Initializing and finalizing the interpreter modules :mod:`builtins`, :mod:`__main__` and :mod:`sys`. It also initializes the module search path (``sys.path``). It does not set ``sys.argv``; use :c:func:`PySys_SetArgvEx` for that. This is a no-op when called for a second time - (without calling :c:func:`Py_Finalize` first). There is no return value; it is a + (without calling :c:func:`Py_FinalizeEx` first). There is no return value; it is a fatal error if the initialization fails. @@ -48,19 +48,20 @@ Initializing and finalizing the interpreter .. c:function:: int Py_IsInitialized() Return true (nonzero) when the Python interpreter has been initialized, false - (zero) if not. After :c:func:`Py_Finalize` is called, this returns false until + (zero) if not. After :c:func:`Py_FinalizeEx` is called, this returns false until :c:func:`Py_Initialize` is called again. -.. c:function:: void Py_Finalize() +.. c:function:: int Py_FinalizeEx() Undo all initializations made by :c:func:`Py_Initialize` and subsequent use of Python/C API functions, and destroy all sub-interpreters (see :c:func:`Py_NewInterpreter` below) that were created and not yet destroyed since the last call to :c:func:`Py_Initialize`. Ideally, this frees all memory allocated by the Python interpreter. This is a no-op when called for a second - time (without calling :c:func:`Py_Initialize` again first). There is no return - value; errors during finalization are ignored. + time (without calling :c:func:`Py_Initialize` again first). Normally the + return value is 0. If there were errors during finalization + (flushing buffered data), -1 is returned. This function is provided for a number of reasons. An embedding application might want to restart Python without having to restart the application itself. @@ -79,7 +80,15 @@ Initializing and finalizing the interpreter freed. Some memory allocated by extension modules may not be freed. Some extensions may not work properly if their initialization routine is called more than once; this can happen if an application calls :c:func:`Py_Initialize` and - :c:func:`Py_Finalize` more than once. + :c:func:`Py_FinalizeEx` more than once. + + .. versionadded:: 3.6 + + +.. c:function:: void Py_Finalize() + + This is a backwards-compatible version of :c:func:`Py_FinalizeEx` that + disregards the return value. Process-wide parameters @@ -107,7 +116,7 @@ Process-wide parameters Note that :data:`sys.stderr` always uses the "backslashreplace" error handler, regardless of this (or any other) setting. - If :c:func:`Py_Finalize` is called, this function will need to be called + If :c:func:`Py_FinalizeEx` is called, this function will need to be called again in order to affect subsequent calls to :c:func:`Py_Initialize`. Returns 0 if successful, a nonzero value on error (e.g. calling after the @@ -918,7 +927,7 @@ using the following functions: entry.) .. index:: - single: Py_Finalize() + single: Py_FinalizeEx() single: Py_Initialize() Extension modules are shared between (sub-)interpreters as follows: the first @@ -928,7 +937,7 @@ using the following functions: and filled with the contents of this copy; the extension's ``init`` function is not called. Note that this is different from what happens when an extension is imported after the interpreter has been completely re-initialized by calling - :c:func:`Py_Finalize` and :c:func:`Py_Initialize`; in that case, the extension's + :c:func:`Py_FinalizeEx` and :c:func:`Py_Initialize`; in that case, the extension's ``initmodule`` function *is* called again. .. index:: single: close() (in module os) @@ -936,14 +945,14 @@ using the following functions: .. c:function:: void Py_EndInterpreter(PyThreadState *tstate) - .. index:: single: Py_Finalize() + .. index:: single: Py_FinalizeEx() Destroy the (sub-)interpreter represented by the given thread state. The given thread state must be the current thread state. See the discussion of thread states below. When the call returns, the current thread state is *NULL*. All thread states associated with this interpreter are destroyed. (The global interpreter lock must be held before calling this function and is still held - when it returns.) :c:func:`Py_Finalize` will destroy all sub-interpreters that + when it returns.) :c:func:`Py_FinalizeEx` will destroy all sub-interpreters that haven't been explicitly destroyed at that point. diff --git a/Doc/c-api/intro.rst b/Doc/c-api/intro.rst index bc3a752..74681d2 100644 --- a/Doc/c-api/intro.rst +++ b/Doc/c-api/intro.rst @@ -64,9 +64,10 @@ The header files are typically installed with Python. On Unix, these are located in the directories :file:`{prefix}/include/pythonversion/` and :file:`{exec_prefix}/include/pythonversion/`, where :envvar:`prefix` and :envvar:`exec_prefix` are defined by the corresponding parameters to Python's -:program:`configure` script and *version* is ``sys.version[:3]``. On Windows, -the headers are installed in :file:`{prefix}/include`, where :envvar:`prefix` is -the installation directory specified to the installer. +:program:`configure` script and *version* is +``'%d.%d' % sys.version_info[:2]``. On Windows, the headers are installed +in :file:`{prefix}/include`, where :envvar:`prefix` is the installation +directory specified to the installer. To include the headers, place both directories (if different) on your compiler's search path for includes. Do *not* place the parent directories on the search @@ -578,9 +579,9 @@ Sometimes, it is desirable to "uninitialize" Python. For instance, the application may want to start over (make another call to :c:func:`Py_Initialize`) or the application is simply done with its use of Python and wants to free memory allocated by Python. This can be accomplished -by calling :c:func:`Py_Finalize`. The function :c:func:`Py_IsInitialized` returns +by calling :c:func:`Py_FinalizeEx`. The function :c:func:`Py_IsInitialized` returns true if Python is currently in the initialized state. More information about -these functions is given in a later chapter. Notice that :c:func:`Py_Finalize` +these functions is given in a later chapter. Notice that :c:func:`Py_FinalizeEx` does *not* free all memory allocated by the Python interpreter, e.g. memory allocated by extension modules currently cannot be released. diff --git a/Doc/c-api/memory.rst b/Doc/c-api/memory.rst index 290ef09..3ff5452 100644 --- a/Doc/c-api/memory.rst +++ b/Doc/c-api/memory.rst @@ -85,9 +85,12 @@ for the I/O buffer escapes completely the Python memory manager. .. seealso:: + The :envvar:`PYTHONMALLOC` environment variable can be used to configure + the memory allocators used by Python. + The :envvar:`PYTHONMALLOCSTATS` environment variable can be used to print - memory allocation statistics every time a new object arena is created, and - on shutdown. + statistics of the :ref:`pymalloc memory allocator <pymalloc>` every time a + new pymalloc object arena is created, and on shutdown. Raw Memory Interface @@ -162,15 +165,17 @@ The following function sets, modeled after the ANSI C standard, but specifying behavior when requesting zero bytes, are available for allocating and releasing memory from the Python heap. -The default memory block allocator uses the following functions: -:c:func:`malloc`, :c:func:`calloc`, :c:func:`realloc` and :c:func:`free`; call -``malloc(1)`` (or ``calloc(1, 1)``) when requesting zero bytes. +By default, these functions use :ref:`pymalloc memory allocator <pymalloc>`. .. warning:: The :term:`GIL <global interpreter lock>` must be held when using these functions. +.. versionchanged:: 3.6 + + The default allocator is now pymalloc instead of system :c:func:`malloc`. + .. c:function:: void* PyMem_Malloc(size_t n) Allocates *n* bytes and returns a pointer of type :c:type:`void\*` to the @@ -292,15 +297,32 @@ Customize Memory Allocators Enum used to identify an allocator domain. Domains: - * :c:data:`PYMEM_DOMAIN_RAW`: functions :c:func:`PyMem_RawMalloc`, - :c:func:`PyMem_RawRealloc`, :c:func:`PyMem_RawCalloc` and - :c:func:`PyMem_RawFree` - * :c:data:`PYMEM_DOMAIN_MEM`: functions :c:func:`PyMem_Malloc`, - :c:func:`PyMem_Realloc`, :c:func:`PyMem_Calloc` and :c:func:`PyMem_Free` - * :c:data:`PYMEM_DOMAIN_OBJ`: functions :c:func:`PyObject_Malloc`, - :c:func:`PyObject_Realloc`, :c:func:`PyObject_Calloc` and - :c:func:`PyObject_Free` + .. c:var:: PYMEM_DOMAIN_RAW + + Functions: + + * :c:func:`PyMem_RawMalloc` + * :c:func:`PyMem_RawRealloc` + * :c:func:`PyMem_RawCalloc` + * :c:func:`PyMem_RawFree` + + .. c:var:: PYMEM_DOMAIN_MEM + + Functions: + + * :c:func:`PyMem_Malloc`, + * :c:func:`PyMem_Realloc` + * :c:func:`PyMem_Calloc` + * :c:func:`PyMem_Free` + .. c:var:: PYMEM_DOMAIN_OBJ + + Functions: + + * :c:func:`PyObject_Malloc` + * :c:func:`PyObject_Realloc` + * :c:func:`PyObject_Calloc` + * :c:func:`PyObject_Free` .. c:function:: void PyMem_GetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator) @@ -325,43 +347,62 @@ Customize Memory Allocators .. c:function:: void PyMem_SetupDebugHooks(void) - Setup hooks to detect bugs in the following Python memory allocator - functions: - - - :c:func:`PyMem_RawMalloc`, :c:func:`PyMem_RawRealloc`, - :c:func:`PyMem_RawCalloc`, :c:func:`PyMem_RawFree` - - :c:func:`PyMem_Malloc`, :c:func:`PyMem_Realloc`, :c:func:`PyMem_Calloc`, - :c:func:`PyMem_Free` - - :c:func:`PyObject_Malloc`, :c:func:`PyObject_Realloc`, - :c:func:`PyObject_Calloc`, :c:func:`PyObject_Free` + Setup hooks to detect bugs in the Python memory allocator functions. Newly allocated memory is filled with the byte ``0xCB``, freed memory is - filled with the byte ``0xDB``. Additional checks: + filled with the byte ``0xDB``. - - detect API violations, ex: :c:func:`PyObject_Free` called on a buffer + Runtime checks: + + - Detect API violations, ex: :c:func:`PyObject_Free` called on a buffer allocated by :c:func:`PyMem_Malloc` - - detect write before the start of the buffer (buffer underflow) - - detect write after the end of the buffer (buffer overflow) + - Detect write before the start of the buffer (buffer underflow) + - Detect write after the end of the buffer (buffer overflow) + - Check that the :term:`GIL <global interpreter lock>` is held when + allocator functions of :c:data:`PYMEM_DOMAIN_OBJ` (ex: + :c:func:`PyObject_Malloc`) and :c:data:`PYMEM_DOMAIN_MEM` (ex: + :c:func:`PyMem_Malloc`) domains are called + + On error, the debug hooks use the :mod:`tracemalloc` module to get the + traceback where a memory block was allocated. The traceback is only + displayed if :mod:`tracemalloc` is tracing Python memory allocations and the + memory block was traced. - The function does nothing if Python is not compiled is debug mode. + These hooks are installed by default if Python is compiled in debug + mode. The :envvar:`PYTHONMALLOC` environment variable can be used to install + debug hooks on a Python compiled in release mode. + .. versionchanged:: 3.6 + This function now also works on Python compiled in release mode. + On error, the debug hooks now use :mod:`tracemalloc` to get the traceback + where a memory block was allocated. The debug hooks now also check + if the GIL is held when functions of :c:data:`PYMEM_DOMAIN_OBJ` and + :c:data:`PYMEM_DOMAIN_MEM` domains are called. -Customize PyObject Arena Allocator -================================== -Python has a *pymalloc* allocator for allocations smaller than 512 bytes. This -allocator is optimized for small objects with a short lifetime. It uses memory -mappings called "arenas" with a fixed size of 256 KB. It falls back to -:c:func:`PyMem_RawMalloc` and :c:func:`PyMem_RawRealloc` for allocations larger -than 512 bytes. *pymalloc* is the default allocator used by -:c:func:`PyObject_Malloc`. +.. _pymalloc: -The default arena allocator uses the following functions: +The pymalloc allocator +====================== + +Python has a *pymalloc* allocator optimized for small objects (smaller or equal +to 512 bytes) with a short lifetime. It uses memory mappings called "arenas" +with a fixed size of 256 KB. It falls back to :c:func:`PyMem_RawMalloc` and +:c:func:`PyMem_RawRealloc` for allocations larger than 512 bytes. + +*pymalloc* is the default allocator of the :c:data:`PYMEM_DOMAIN_MEM` (ex: +:c:func:`PyObject_Malloc`) and :c:data:`PYMEM_DOMAIN_OBJ` (ex: +:c:func:`PyObject_Malloc`) domains. + +The arena allocator uses the following functions: * :c:func:`VirtualAlloc` and :c:func:`VirtualFree` on Windows, * :c:func:`mmap` and :c:func:`munmap` if available, * :c:func:`malloc` and :c:func:`free` otherwise. +Customize pymalloc Arena Allocator +---------------------------------- + .. versionadded:: 3.4 .. c:type:: PyObjectArenaAllocator diff --git a/Doc/c-api/structures.rst b/Doc/c-api/structures.rst index cc84314..e9e8add 100644 --- a/Doc/c-api/structures.rst +++ b/Doc/c-api/structures.rst @@ -150,8 +150,9 @@ specific C type of the *self* object. The :attr:`ml_flags` field is a bitfield which can include the following flags. The individual flags indicate either a calling convention or a binding convention. Of the calling convention flags, only :const:`METH_VARARGS` and -:const:`METH_KEYWORDS` can be combined. Any of the calling convention flags -can be combined with a binding flag. +:const:`METH_KEYWORDS` can be combined (but note that :const:`METH_KEYWORDS` +alone is equivalent to ``METH_VARARGS | METH_KEYWORDS``). Any of the calling +convention flags can be combined with a binding flag. .. data:: METH_VARARGS diff --git a/Doc/c-api/sys.rst b/Doc/c-api/sys.rst index 3d83b27..035cdc1 100644 --- a/Doc/c-api/sys.rst +++ b/Doc/c-api/sys.rst @@ -5,6 +5,17 @@ Operating System Utilities ========================== +.. c:function:: PyObject* PyOS_FSPath(PyObject *path) + + Return the file system representation for *path*. If the object is a + :class:`str` or :class:`bytes` object, then its reference count is + incremented. If the object implements the :class:`os.PathLike` interface, + then :meth:`~os.PathLike.__fspath__` is returned as long as it is a + :class:`str` or :class:`bytes` object. Otherwise :exc:`TypeError` is raised + and ``NULL`` is returned. + + .. versionadded:: 3.6 + .. c:function:: int Py_FdIsInteractive(FILE *fp, const char *filename) @@ -212,20 +223,24 @@ Process Control .. c:function:: void Py_Exit(int status) .. index:: - single: Py_Finalize() + single: Py_FinalizeEx() single: exit() - Exit the current process. This calls :c:func:`Py_Finalize` and then calls the - standard C library function ``exit(status)``. + Exit the current process. This calls :c:func:`Py_FinalizeEx` and then calls the + standard C library function ``exit(status)``. If :c:func:`Py_FinalizeEx` + indicates an error, the exit status is set to 120. + + .. versionchanged:: 3.6 + Errors from finalization no longer ignored. .. c:function:: int Py_AtExit(void (*func) ()) .. index:: - single: Py_Finalize() + single: Py_FinalizeEx() single: cleanup functions - Register a cleanup function to be called by :c:func:`Py_Finalize`. The cleanup + Register a cleanup function to be called by :c:func:`Py_FinalizeEx`. The cleanup function will be called with no arguments and should return no value. At most 32 cleanup functions can be registered. When the registration is successful, :c:func:`Py_AtExit` returns ``0``; on failure, it returns ``-1``. The cleanup |