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Diffstat (limited to 'Doc/c-api/init.rst')
| -rw-r--r-- | Doc/c-api/init.rst | 336 |
1 files changed, 176 insertions, 160 deletions
diff --git a/Doc/c-api/init.rst b/Doc/c-api/init.rst index 7e9d44c..e50c417 100644 --- a/Doc/c-api/init.rst +++ b/Doc/c-api/init.rst @@ -12,13 +12,11 @@ Initializing and finalizing the interpreter =========================================== -.. cfunction:: void Py_Initialize() +.. c:function:: void Py_Initialize() .. index:: single: Py_SetProgramName() single: PyEval_InitThreads() - single: PyEval_ReleaseLock() - single: PyEval_AcquireLock() single: modules (in module sys) single: path (in module sys) module: builtins @@ -31,38 +29,37 @@ Initializing and finalizing the interpreter Initialize the Python interpreter. In an application embedding Python, this should be called before using any other Python/C API functions; with the - exception of :cfunc:`Py_SetProgramName`, :cfunc:`PyEval_InitThreads`, - :cfunc:`PyEval_ReleaseLock`, and :cfunc:`PyEval_AcquireLock`. This initializes + exception of :c:func:`Py_SetProgramName` and :c:func:`Py_SetPath`. This initializes the table of loaded modules (``sys.modules``), and creates the fundamental modules :mod:`builtins`, :mod:`__main__` and :mod:`sys`. It also initializes the module search path (``sys.path``). It does not set ``sys.argv``; use - :cfunc:`PySys_SetArgvEx` for that. This is a no-op when called for a second time - (without calling :cfunc:`Py_Finalize` first). There is no return value; it is a + :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 fatal error if the initialization fails. -.. cfunction:: void Py_InitializeEx(int initsigs) +.. c:function:: void Py_InitializeEx(int initsigs) - This function works like :cfunc:`Py_Initialize` if *initsigs* is 1. If + This function works like :c:func:`Py_Initialize` if *initsigs* is 1. If *initsigs* is 0, it skips initialization registration of signal handlers, which might be useful when Python is embedded. -.. cfunction:: int Py_IsInitialized() +.. c:function:: int Py_IsInitialized() Return true (nonzero) when the Python interpreter has been initialized, false - (zero) if not. After :cfunc:`Py_Finalize` is called, this returns false until - :cfunc:`Py_Initialize` is called again. + (zero) if not. After :c:func:`Py_Finalize` is called, this returns false until + :c:func:`Py_Initialize` is called again. -.. cfunction:: void Py_Finalize() +.. c:function:: void Py_Finalize() - Undo all initializations made by :cfunc:`Py_Initialize` and subsequent use of + Undo all initializations made by :c:func:`Py_Initialize` and subsequent use of Python/C API functions, and destroy all sub-interpreters (see - :cfunc:`Py_NewInterpreter` below) that were created and not yet destroyed since - the last call to :cfunc:`Py_Initialize`. Ideally, this frees all memory + :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 :cfunc:`Py_Initialize` again first). There is no return + time (without calling :c:func:`Py_Initialize` again first). There is no return value; errors during finalization are ignored. This function is provided for a number of reasons. An embedding application @@ -81,26 +78,26 @@ Initializing and finalizing the interpreter please report it). Memory tied up in circular references between objects is not 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 :cfunc:`Py_Initialize` and - :cfunc:`Py_Finalize` more than once. + than once; this can happen if an application calls :c:func:`Py_Initialize` and + :c:func:`Py_Finalize` more than once. Process-wide parameters ======================= -.. cfunction:: void Py_SetProgramName(wchar_t *name) +.. c:function:: void Py_SetProgramName(wchar_t *name) .. index:: single: Py_Initialize() single: main() single: Py_GetPath() - This function should be called before :cfunc:`Py_Initialize` is called for + This function should be called before :c:func:`Py_Initialize` is called for the first time, if it is called at all. It tells the interpreter the value - of the ``argv[0]`` argument to the :cfunc:`main` function of the program + of the ``argv[0]`` argument to the :c:func:`main` function of the program (converted to wide characters). - This is used by :cfunc:`Py_GetPath` and some other functions below to find + This is used by :c:func:`Py_GetPath` and some other functions below to find the Python run-time libraries relative to the interpreter executable. The default value is ``'python'``. The argument should point to a zero-terminated wide character string in static storage whose contents will not @@ -108,20 +105,20 @@ Process-wide parameters interpreter will change the contents of this storage. -.. cfunction:: wchar* Py_GetProgramName() +.. c:function:: wchar* Py_GetProgramName() .. index:: single: Py_SetProgramName() - Return the program name set with :cfunc:`Py_SetProgramName`, or the default. + Return the program name set with :c:func:`Py_SetProgramName`, or the default. The returned string points into static storage; the caller should not modify its value. -.. cfunction:: wchar_t* Py_GetPrefix() +.. c:function:: wchar_t* Py_GetPrefix() Return the *prefix* for installed platform-independent files. This is derived through a number of complicated rules from the program name set with - :cfunc:`Py_SetProgramName` and some environment variables; for example, if the + :c:func:`Py_SetProgramName` and some environment variables; for example, if the program name is ``'/usr/local/bin/python'``, the prefix is ``'/usr/local'``. The returned string points into static storage; the caller should not modify its value. This corresponds to the :makevar:`prefix` variable in the top-level @@ -130,11 +127,11 @@ Process-wide parameters It is only useful on Unix. See also the next function. -.. cfunction:: wchar_t* Py_GetExecPrefix() +.. c:function:: wchar_t* Py_GetExecPrefix() Return the *exec-prefix* for installed platform-*dependent* files. This is derived through a number of complicated rules from the program name set with - :cfunc:`Py_SetProgramName` and some environment variables; for example, if the + :c:func:`Py_SetProgramName` and some environment variables; for example, if the program name is ``'/usr/local/bin/python'``, the exec-prefix is ``'/usr/local'``. The returned string points into static storage; the caller should not modify its value. This corresponds to the :makevar:`exec_prefix` @@ -165,7 +162,7 @@ Process-wide parameters platform. -.. cfunction:: wchar_t* Py_GetProgramFullPath() +.. c:function:: wchar_t* Py_GetProgramFullPath() .. index:: single: Py_SetProgramName() @@ -173,19 +170,20 @@ Process-wide parameters Return the full program name of the Python executable; this is computed as a side-effect of deriving the default module search path from the program name - (set by :cfunc:`Py_SetProgramName` above). The returned string points into + (set by :c:func:`Py_SetProgramName` above). The returned string points into static storage; the caller should not modify its value. The value is available to Python code as ``sys.executable``. -.. cfunction:: wchar_t* Py_GetPath() +.. c:function:: wchar_t* Py_GetPath() .. index:: triple: module; search; path single: path (in module sys) + single: Py_SetPath() Return the default module search path; this is computed from the program name - (set by :cfunc:`Py_SetProgramName` above) and some environment variables. + (set by :c:func:`Py_SetProgramName` above) and some environment variables. The returned string consists of a series of directory names separated by a platform dependent delimiter character. The delimiter character is ``':'`` on Unix and Mac OS X, ``';'`` on Windows. The returned string points into @@ -197,7 +195,26 @@ Process-wide parameters .. XXX should give the exact rules -.. cfunction:: const char* Py_GetVersion() +.. c:function:: void Py_SetPath(const wchar_t *) + + .. index:: + triple: module; search; path + single: path (in module sys) + single: Py_GetPath() + + Set the default module search path. If this function is called before + :c:func:`Py_Initialize`, then :c:func:`Py_GetPath` won't attempt to compute a + default search path but uses the one provided instead. This is useful if + Python is embedded by an application that has full knowledge of the location + of all modules. The path components should be separated by semicolons. + + This also causes :data:`sys.executable` to be set only to the raw program + name (see :c:func:`Py_SetProgramName`) and for :data:`sys.prefix` and + :data:`sys.exec_prefix` to be empty. It is up to the caller to modify these + if required after calling :c:func:`Py_Initialize`. + + +.. c:function:: const char* Py_GetVersion() Return the version of this Python interpreter. This is a string that looks something like :: @@ -212,7 +229,7 @@ Process-wide parameters modify its value. The value is available to Python code as :data:`sys.version`. -.. cfunction:: const char* Py_GetPlatform() +.. c:function:: const char* Py_GetPlatform() .. index:: single: platform (in module sys) @@ -225,7 +242,7 @@ Process-wide parameters to Python code as ``sys.platform``. -.. cfunction:: const char* Py_GetCopyright() +.. c:function:: const char* Py_GetCopyright() Return the official copyright string for the current Python version, for example @@ -237,7 +254,7 @@ Process-wide parameters value. The value is available to Python code as ``sys.copyright``. -.. cfunction:: const char* Py_GetCompiler() +.. c:function:: const char* Py_GetCompiler() Return an indication of the compiler used to build the current Python version, in square brackets, for example:: @@ -251,7 +268,7 @@ Process-wide parameters ``sys.version``. -.. cfunction:: const char* Py_GetBuildInfo() +.. c:function:: const char* Py_GetBuildInfo() Return information about the sequence number and build date and time of the current Python interpreter instance, for example :: @@ -265,7 +282,7 @@ Process-wide parameters ``sys.version``. -.. cfunction:: void PySys_SetArgvEx(int argc, wchar_t **argv, int updatepath) +.. c:function:: void PySys_SetArgvEx(int argc, wchar_t **argv, int updatepath) .. index:: single: main() @@ -273,12 +290,12 @@ Process-wide parameters single: argv (in module sys) Set :data:`sys.argv` based on *argc* and *argv*. These parameters are - similar to those passed to the program's :cfunc:`main` function with the + similar to those passed to the program's :c:func:`main` function with the difference that the first entry should refer to the script file to be executed rather than the executable hosting the Python interpreter. If there isn't a script that will be run, the first entry in *argv* can be an empty string. If this function fails to initialize :data:`sys.argv`, a fatal - condition is signalled using :cfunc:`Py_FatalError`. + condition is signalled using :c:func:`Py_FatalError`. If *updatepath* is zero, this is all the function does. If *updatepath* is non-zero, the function also modifies :data:`sys.path` according to the @@ -300,7 +317,7 @@ Process-wide parameters On versions before 3.1.3, you can achieve the same effect by manually popping the first :data:`sys.path` element after having called - :cfunc:`PySys_SetArgv`, for example using:: + :c:func:`PySys_SetArgv`, for example using:: PyRun_SimpleString("import sys; sys.path.pop(0)\n"); @@ -310,12 +327,12 @@ Process-wide parameters check w/ Guido. -.. cfunction:: void PySys_SetArgv(int argc, wchar_t **argv) +.. c:function:: void PySys_SetArgv(int argc, wchar_t **argv) - This function works like :cfunc:`PySys_SetArgvEx` with *updatepath* set to 1. + This function works like :c:func:`PySys_SetArgvEx` with *updatepath* set to 1. -.. cfunction:: void Py_SetPythonHome(wchar_t *home) +.. c:function:: void Py_SetPythonHome(wchar_t *home) Set the default "home" directory, that is, the location of the standard Python libraries. See :envvar:`PYTHONHOME` for the meaning of the @@ -327,10 +344,10 @@ Process-wide parameters this storage. -.. cfunction:: w_char* Py_GetPythonHome() +.. c:function:: w_char* Py_GetPythonHome() Return the default "home", that is, the value set by a previous call to - :cfunc:`Py_SetPythonHome`, or the value of the :envvar:`PYTHONHOME` + :c:func:`Py_SetPythonHome`, or the value of the :envvar:`PYTHONHOME` environment variable if it is set. @@ -352,12 +369,12 @@ operations could cause problems in a multi-threaded program: for example, when two threads simultaneously increment the reference count of the same object, the reference count could end up being incremented only once instead of twice. -.. index:: single: setcheckinterval() (in module sys) +.. index:: single: setswitchinterval() (in module sys) Therefore, the rule exists that only the thread that has acquired the :term:`GIL` may operate on Python objects or call Python/C API functions. In order to emulate concurrency of execution, the interpreter regularly -tries to switch threads (see :func:`sys.setcheckinterval`). The lock is also +tries to switch threads (see :func:`sys.setswitchinterval`). The lock is also released around potentially blocking I/O operations like reading or writing a file, so that other Python threads can run in the meantime. @@ -366,9 +383,9 @@ a file, so that other Python threads can run in the meantime. single: PyThreadState The Python interpreter keeps some thread-specific bookkeeping information -inside a data structure called :ctype:`PyThreadState`. There's also one -global variable pointing to the current :ctype:`PyThreadState`: it can -be retrieved using :cfunc:`PyThreadState_Get`. +inside a data structure called :c:type:`PyThreadState`. There's also one +global variable pointing to the current :c:type:`PyThreadState`: it can +be retrieved using :c:func:`PyThreadState_Get`. Releasing the GIL from extension code ------------------------------------- @@ -392,8 +409,8 @@ This is so common that a pair of macros exists to simplify it:: single: Py_BEGIN_ALLOW_THREADS single: Py_END_ALLOW_THREADS -The :cmacro:`Py_BEGIN_ALLOW_THREADS` macro opens a new block and declares a -hidden local variable; the :cmacro:`Py_END_ALLOW_THREADS` macro closes the +The :c:macro:`Py_BEGIN_ALLOW_THREADS` macro opens a new block and declares a +hidden local variable; the :c:macro:`Py_END_ALLOW_THREADS` macro closes the block. These two macros are still available when Python is compiled without thread support (they simply have an empty expansion). @@ -443,7 +460,7 @@ storing their thread state pointer, before you can start using the Python/C API. When you are done, you should reset the thread state pointer, release the GIL, and finally free the thread state data structure. -The :cfunc:`PyGILState_Ensure` and :cfunc:`PyGILState_Release` functions do +The :c:func:`PyGILState_Ensure` and :c:func:`PyGILState_Release` functions do all of the above automatically. The typical idiom for calling into Python from a C thread is:: @@ -457,14 +474,14 @@ from a C thread is:: /* Release the thread. No Python API allowed beyond this point. */ PyGILState_Release(gstate); -Note that the :cfunc:`PyGILState_\*` functions assume there is only one global -interpreter (created automatically by :cfunc:`Py_Initialize`). Python +Note that the :c:func:`PyGILState_\*` functions assume there is only one global +interpreter (created automatically by :c:func:`Py_Initialize`). Python supports the creation of additional interpreters (using -:cfunc:`Py_NewInterpreter`), but mixing multiple interpreters and the -:cfunc:`PyGILState_\*` API is unsupported. +:c:func:`Py_NewInterpreter`), but mixing multiple interpreters and the +:c:func:`PyGILState_\*` API is unsupported. Another important thing to note about threads is their behaviour in the face -of the C :cfunc:`fork` call. On most systems with :cfunc:`fork`, after a +of the C :c:func:`fork` call. On most systems with :c:func:`fork`, after a process forks only the thread that issued the fork will exist. That also means any locks held by other threads will never be released. Python solves this for :func:`os.fork` by acquiring the locks it uses internally before @@ -472,12 +489,12 @@ the fork, and releasing them afterwards. In addition, it resets any :ref:`lock-objects` in the child. When extending or embedding Python, there is no way to inform Python of additional (non-Python) locks that need to be acquired before or reset after a fork. OS facilities such as -:cfunc:`pthread_atfork` would need to be used to accomplish the same thing. -Additionally, when extending or embedding Python, calling :cfunc:`fork` +:c:func:`pthread_atfork` would need to be used to accomplish the same thing. +Additionally, when extending or embedding Python, calling :c:func:`fork` directly rather than through :func:`os.fork` (and returning to or calling into Python) may result in a deadlock by one of Python's internal locks being held by a thread that is defunct after the fork. -:cfunc:`PyOS_AfterFork` tries to reset the necessary locks, but is not +:c:func:`PyOS_AfterFork` tries to reset the necessary locks, but is not always able to. @@ -487,7 +504,7 @@ High-level API These are the most commonly used types and functions when writing C extension code, or when embedding the Python interpreter: -.. ctype:: PyInterpreterState +.. c:type:: PyInterpreterState This data structure represents the state shared by a number of cooperating threads. Threads belonging to the same interpreter share their module @@ -500,31 +517,30 @@ code, or when embedding the Python interpreter: interpreter they belong. -.. ctype:: PyThreadState +.. c:type:: PyThreadState This data structure represents the state of a single thread. The only public - data member is :ctype:`PyInterpreterState \*`:attr:`interp`, which points to + data member is :c:type:`PyInterpreterState \*`:attr:`interp`, which points to this thread's interpreter state. -.. cfunction:: void PyEval_InitThreads() +.. c:function:: void PyEval_InitThreads() .. index:: - single: PyEval_ReleaseLock() + single: PyEval_AcquireThread() single: PyEval_ReleaseThread() single: PyEval_SaveThread() single: PyEval_RestoreThread() Initialize and acquire the global interpreter lock. It should be called in the main thread before creating a second thread or engaging in any other thread - operations such as :cfunc:`PyEval_ReleaseLock` or - ``PyEval_ReleaseThread(tstate)``. It is not needed before calling - :cfunc:`PyEval_SaveThread` or :cfunc:`PyEval_RestoreThread`. + operations such as ``PyEval_ReleaseThread(tstate)``. It is not needed before + calling :c:func:`PyEval_SaveThread` or :c:func:`PyEval_RestoreThread`. - .. index:: single: Py_Initialize() + This is a no-op when called for a second time. - This is a no-op when called for a second time. It is safe to call this function - before calling :cfunc:`Py_Initialize`. + .. versionchanged:: 3.2 + This function cannot be called before :c:func:`Py_Initialize()` anymore. .. index:: module: _thread @@ -537,7 +553,7 @@ code, or when embedding the Python interpreter: when this function initializes the global interpreter lock, it also acquires it. Before the Python :mod:`_thread` module creates a new thread, knowing that either it has the lock or the lock hasn't been created yet, it calls - :cfunc:`PyEval_InitThreads`. When this call returns, it is guaranteed that + :c:func:`PyEval_InitThreads`. When this call returns, it is guaranteed that the lock has been created and that the calling thread has acquired it. It is **not** safe to call this function when it is unknown which thread (if @@ -546,15 +562,15 @@ code, or when embedding the Python interpreter: This function is not available when thread support is disabled at compile time. -.. cfunction:: int PyEval_ThreadsInitialized() +.. c:function:: int PyEval_ThreadsInitialized() - Returns a non-zero value if :cfunc:`PyEval_InitThreads` has been called. This + Returns a non-zero value if :c:func:`PyEval_InitThreads` has been called. This function can be called without holding the GIL, and therefore can be used to avoid calls to the locking API when running single-threaded. This function is not available when thread support is disabled at compile time. -.. cfunction:: PyThreadState* PyEval_SaveThread() +.. c:function:: PyThreadState* PyEval_SaveThread() Release the global interpreter lock (if it has been created and thread support is enabled) and reset the thread state to *NULL*, returning the @@ -563,7 +579,7 @@ code, or when embedding the Python interpreter: when thread support is disabled at compile time.) -.. cfunction:: void PyEval_RestoreThread(PyThreadState *tstate) +.. c:function:: void PyEval_RestoreThread(PyThreadState *tstate) Acquire the global interpreter lock (if it has been created and thread support is enabled) and set the thread state to *tstate*, which must not be @@ -572,23 +588,23 @@ code, or when embedding the Python interpreter: when thread support is disabled at compile time.) -.. cfunction:: PyThreadState* PyThreadState_Get() +.. c:function:: PyThreadState* PyThreadState_Get() Return the current thread state. The global interpreter lock must be held. When the current thread state is *NULL*, this issues a fatal error (so that the caller needn't check for *NULL*). -.. cfunction:: PyThreadState* PyThreadState_Swap(PyThreadState *tstate) +.. c:function:: PyThreadState* PyThreadState_Swap(PyThreadState *tstate) Swap the current thread state with the thread state given by the argument *tstate*, which may be *NULL*. The global interpreter lock must be held and is not released. -.. cfunction:: void PyEval_ReInitThreads() +.. c:function:: void PyEval_ReInitThreads() - This function is called from :cfunc:`PyOS_AfterFork` to ensure that newly + This function is called from :c:func:`PyOS_AfterFork` to ensure that newly created child processes don't hold locks referring to threads which are not running in the child process. @@ -596,71 +612,71 @@ code, or when embedding the Python interpreter: The following functions use thread-local storage, and are not compatible with sub-interpreters: -.. cfunction:: PyGILState_STATE PyGILState_Ensure() +.. c:function:: PyGILState_STATE PyGILState_Ensure() Ensure that the current thread is ready to call the Python C API regardless of the current state of Python, or of the global interpreter lock. This may be called as many times as desired by a thread as long as each call is - matched with a call to :cfunc:`PyGILState_Release`. In general, other - thread-related APIs may be used between :cfunc:`PyGILState_Ensure` and - :cfunc:`PyGILState_Release` calls as long as the thread state is restored to + matched with a call to :c:func:`PyGILState_Release`. In general, other + thread-related APIs may be used between :c:func:`PyGILState_Ensure` and + :c:func:`PyGILState_Release` calls as long as the thread state is restored to its previous state before the Release(). For example, normal usage of the - :cmacro:`Py_BEGIN_ALLOW_THREADS` and :cmacro:`Py_END_ALLOW_THREADS` macros is + :c:macro:`Py_BEGIN_ALLOW_THREADS` and :c:macro:`Py_END_ALLOW_THREADS` macros is acceptable. The return value is an opaque "handle" to the thread state when - :cfunc:`PyGILState_Ensure` was called, and must be passed to - :cfunc:`PyGILState_Release` to ensure Python is left in the same state. Even + :c:func:`PyGILState_Ensure` was called, and must be passed to + :c:func:`PyGILState_Release` to ensure Python is left in the same state. Even though recursive calls are allowed, these handles *cannot* be shared - each - unique call to :cfunc:`PyGILState_Ensure` must save the handle for its call - to :cfunc:`PyGILState_Release`. + unique call to :c:func:`PyGILState_Ensure` must save the handle for its call + to :c:func:`PyGILState_Release`. When the function returns, the current thread will hold the GIL and be able to call arbitrary Python code. Failure is a fatal error. -.. cfunction:: void PyGILState_Release(PyGILState_STATE) +.. c:function:: void PyGILState_Release(PyGILState_STATE) Release any resources previously acquired. After this call, Python's state will - be the same as it was prior to the corresponding :cfunc:`PyGILState_Ensure` call + be the same as it was prior to the corresponding :c:func:`PyGILState_Ensure` call (but generally this state will be unknown to the caller, hence the use of the GILState API). - Every call to :cfunc:`PyGILState_Ensure` must be matched by a call to - :cfunc:`PyGILState_Release` on the same thread. + Every call to :c:func:`PyGILState_Ensure` must be matched by a call to + :c:func:`PyGILState_Release` on the same thread. The following macros are normally used without a trailing semicolon; look for example usage in the Python source distribution. -.. cmacro:: Py_BEGIN_ALLOW_THREADS +.. c:macro:: Py_BEGIN_ALLOW_THREADS This macro expands to ``{ PyThreadState *_save; _save = PyEval_SaveThread();``. Note that it contains an opening brace; it must be matched with a following - :cmacro:`Py_END_ALLOW_THREADS` macro. See above for further discussion of this + :c:macro:`Py_END_ALLOW_THREADS` macro. See above for further discussion of this macro. It is a no-op when thread support is disabled at compile time. -.. cmacro:: Py_END_ALLOW_THREADS +.. c:macro:: Py_END_ALLOW_THREADS This macro expands to ``PyEval_RestoreThread(_save); }``. Note that it contains a closing brace; it must be matched with an earlier - :cmacro:`Py_BEGIN_ALLOW_THREADS` macro. See above for further discussion of + :c:macro:`Py_BEGIN_ALLOW_THREADS` macro. See above for further discussion of this macro. It is a no-op when thread support is disabled at compile time. -.. cmacro:: Py_BLOCK_THREADS +.. c:macro:: Py_BLOCK_THREADS This macro expands to ``PyEval_RestoreThread(_save);``: it is equivalent to - :cmacro:`Py_END_ALLOW_THREADS` without the closing brace. It is a no-op when + :c:macro:`Py_END_ALLOW_THREADS` without the closing brace. It is a no-op when thread support is disabled at compile time. -.. cmacro:: Py_UNBLOCK_THREADS +.. c:macro:: Py_UNBLOCK_THREADS This macro expands to ``_save = PyEval_SaveThread();``: it is equivalent to - :cmacro:`Py_BEGIN_ALLOW_THREADS` without the opening brace and variable + :c:macro:`Py_BEGIN_ALLOW_THREADS` without the opening brace and variable declaration. It is a no-op when thread support is disabled at compile time. @@ -672,47 +688,47 @@ at compile time, and must be called only when the global interpreter lock has been created. -.. cfunction:: PyInterpreterState* PyInterpreterState_New() +.. c:function:: PyInterpreterState* PyInterpreterState_New() Create a new interpreter state object. The global interpreter lock need not be held, but may be held if it is necessary to serialize calls to this function. -.. cfunction:: void PyInterpreterState_Clear(PyInterpreterState *interp) +.. c:function:: void PyInterpreterState_Clear(PyInterpreterState *interp) Reset all information in an interpreter state object. The global interpreter lock must be held. -.. cfunction:: void PyInterpreterState_Delete(PyInterpreterState *interp) +.. c:function:: void PyInterpreterState_Delete(PyInterpreterState *interp) Destroy an interpreter state object. The global interpreter lock need not be held. The interpreter state must have been reset with a previous call to - :cfunc:`PyInterpreterState_Clear`. + :c:func:`PyInterpreterState_Clear`. -.. cfunction:: PyThreadState* PyThreadState_New(PyInterpreterState *interp) +.. c:function:: PyThreadState* PyThreadState_New(PyInterpreterState *interp) Create a new thread state object belonging to the given interpreter object. The global interpreter lock need not be held, but may be held if it is necessary to serialize calls to this function. -.. cfunction:: void PyThreadState_Clear(PyThreadState *tstate) +.. c:function:: void PyThreadState_Clear(PyThreadState *tstate) Reset all information in a thread state object. The global interpreter lock must be held. -.. cfunction:: void PyThreadState_Delete(PyThreadState *tstate) +.. c:function:: void PyThreadState_Delete(PyThreadState *tstate) Destroy a thread state object. The global interpreter lock need not be held. The thread state must have been reset with a previous call to - :cfunc:`PyThreadState_Clear`. + :c:func:`PyThreadState_Clear`. -.. cfunction:: PyObject* PyThreadState_GetDict() +.. c:function:: PyObject* PyThreadState_GetDict() Return a dictionary in which extensions can store thread-specific state information. Each extension should use a unique key to use to store state in @@ -721,7 +737,7 @@ been created. the caller should assume no current thread state is available. -.. cfunction:: int PyThreadState_SetAsyncExc(long id, PyObject *exc) +.. c:function:: int PyThreadState_SetAsyncExc(long id, PyObject *exc) Asynchronously raise an exception in a thread. The *id* argument is the thread id of the target thread; *exc* is the exception object to be raised. This @@ -732,18 +748,18 @@ been created. exception (if any) for the thread is cleared. This raises no exceptions. -.. cfunction:: void PyEval_AcquireThread(PyThreadState *tstate) +.. c:function:: void PyEval_AcquireThread(PyThreadState *tstate) Acquire the global interpreter lock and set the current thread state to *tstate*, which should not be *NULL*. The lock must have been created earlier. If this thread already has the lock, deadlock ensues. - :cfunc:`PyEval_RestoreThread` is a higher-level function which is always + :c:func:`PyEval_RestoreThread` is a higher-level function which is always available (even when thread support isn't enabled or when threads have not been initialized). -.. cfunction:: void PyEval_ReleaseThread(PyThreadState *tstate) +.. c:function:: void PyEval_ReleaseThread(PyThreadState *tstate) Reset the current thread state to *NULL* and release the global interpreter lock. The lock must have been created earlier and must be held by the current @@ -751,29 +767,29 @@ been created. that it represents the current thread state --- if it isn't, a fatal error is reported. - :cfunc:`PyEval_SaveThread` is a higher-level function which is always + :c:func:`PyEval_SaveThread` is a higher-level function which is always available (even when thread support isn't enabled or when threads have not been initialized). -.. cfunction:: void PyEval_AcquireLock() +.. c:function:: void PyEval_AcquireLock() Acquire the global interpreter lock. The lock must have been created earlier. If this thread already has the lock, a deadlock ensues. - .. warning:: - This function does not change the current thread state. Please use - :cfunc:`PyEval_RestoreThread` or :cfunc:`PyEval_AcquireThread` + .. deprecated:: 3.2 + This function does not update the current thread state. Please use + :c:func:`PyEval_RestoreThread` or :c:func:`PyEval_AcquireThread` instead. -.. cfunction:: void PyEval_ReleaseLock() +.. c:function:: void PyEval_ReleaseLock() Release the global interpreter lock. The lock must have been created earlier. - .. warning:: - This function does not change the current thread state. Please use - :cfunc:`PyEval_SaveThread` or :cfunc:`PyEval_ReleaseThread` + .. deprecated:: 3.2 + This function does not update the current thread state. Please use + :c:func:`PyEval_SaveThread` or :c:func:`PyEval_ReleaseThread` instead. @@ -784,11 +800,11 @@ While in most uses, you will only embed a single Python interpreter, there are cases where you need to create several independent interpreters in the same process and perhaps even in the same thread. Sub-interpreters allow you to do that. You can switch between sub-interpreters using the -:cfunc:`PyThreadState_Swap` function. You can create and destroy them +:c:func:`PyThreadState_Swap` function. You can create and destroy them using the following functions: -.. cfunction:: PyThreadState* Py_NewInterpreter() +.. c:function:: PyThreadState* Py_NewInterpreter() .. index:: module: builtins @@ -830,13 +846,13 @@ 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 - :cfunc:`Py_Finalize` and :cfunc:`Py_Initialize`; in that case, the extension's + :c:func:`Py_Finalize` and :c:func:`Py_Initialize`; in that case, the extension's ``initmodule`` function *is* called again. .. index:: single: close() (in module os) -.. cfunction:: void Py_EndInterpreter(PyThreadState *tstate) +.. c:function:: void Py_EndInterpreter(PyThreadState *tstate) .. index:: single: Py_Finalize() @@ -845,7 +861,7 @@ using the following functions: 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.) :cfunc:`Py_Finalize` will destroy all sub-interpreters that + when it returns.) :c:func:`Py_Finalize` will destroy all sub-interpreters that haven't been explicitly destroyed at that point. @@ -866,11 +882,11 @@ instances or classes between sub-interpreters, since import operations executed by such objects may affect the wrong (sub-)interpreter's dictionary of loaded modules. -Also note that combining this functionality with :cfunc:`PyGILState_\*` APIs +Also note that combining this functionality with :c:func:`PyGILState_\*` APIs is delicate, become these APIs assume a bijection between Python thread states and OS-level threads, an assumption broken by the presence of sub-interpreters. It is highly recommended that you don't switch sub-interpreters between a pair -of matching :cfunc:`PyGILState_Ensure` and :cfunc:`PyGILState_Release` calls. +of matching :c:func:`PyGILState_Ensure` and :c:func:`PyGILState_Release` calls. Furthermore, extensions (such as :mod:`ctypes`) using these APIs to allow calling of Python code from non-Python created threads will probably be broken when using sub-interpreters. @@ -892,7 +908,7 @@ a worker thread and the actual call than made at the earliest convenience by the main thread where it has possession of the global interpreter lock and can perform any Python API calls. -.. cfunction:: int Py_AddPendingCall(int (*func)(void *), void *arg) +.. c:function:: int Py_AddPendingCall(int (*func)(void *), void *arg) .. index:: single: Py_AddPendingCall() @@ -937,10 +953,10 @@ events reported to the trace function are the same as had been reported to the Python-level trace functions in previous versions. -.. ctype:: int (*Py_tracefunc)(PyObject *obj, PyFrameObject *frame, int what, PyObject *arg) +.. c:type:: int (*Py_tracefunc)(PyObject *obj, PyFrameObject *frame, int what, PyObject *arg) - The type of the trace function registered using :cfunc:`PyEval_SetProfile` and - :cfunc:`PyEval_SetTrace`. The first parameter is the object passed to the + The type of the trace function registered using :c:func:`PyEval_SetProfile` and + :c:func:`PyEval_SetTrace`. The first parameter is the object passed to the registration function as *obj*, *frame* is the frame object to which the event pertains, *what* is one of the constants :const:`PyTrace_CALL`, :const:`PyTrace_EXCEPTION`, :const:`PyTrace_LINE`, :const:`PyTrace_RETURN`, @@ -968,18 +984,18 @@ Python-level trace functions in previous versions. +------------------------------+--------------------------------------+ -.. cvar:: int PyTrace_CALL +.. c:var:: int PyTrace_CALL - The value of the *what* parameter to a :ctype:`Py_tracefunc` function when a new + The value of the *what* parameter to a :c:type:`Py_tracefunc` function when a new call to a function or method is being reported, or a new entry into a generator. Note that the creation of the iterator for a generator function is not reported as there is no control transfer to the Python bytecode in the corresponding frame. -.. cvar:: int PyTrace_EXCEPTION +.. c:var:: int PyTrace_EXCEPTION - The value of the *what* parameter to a :ctype:`Py_tracefunc` function when an + The value of the *what* parameter to a :c:type:`Py_tracefunc` function when an exception has been raised. The callback function is called with this value for *what* when after any bytecode is processed after which the exception becomes set within the frame being executed. The effect of this is that as exception @@ -988,37 +1004,37 @@ Python-level trace functions in previous versions. these events; they are not needed by the profiler. -.. cvar:: int PyTrace_LINE +.. c:var:: int PyTrace_LINE The value passed as the *what* parameter to a trace function (but not a profiling function) when a line-number event is being reported. -.. cvar:: int PyTrace_RETURN +.. c:var:: int PyTrace_RETURN - The value for the *what* parameter to :ctype:`Py_tracefunc` functions when a + The value for the *what* parameter to :c:type:`Py_tracefunc` functions when a call is returning without propagating an exception. -.. cvar:: int PyTrace_C_CALL +.. c:var:: int PyTrace_C_CALL - The value for the *what* parameter to :ctype:`Py_tracefunc` functions when a C + The value for the *what* parameter to :c:type:`Py_tracefunc` functions when a C function is about to be called. -.. cvar:: int PyTrace_C_EXCEPTION +.. c:var:: int PyTrace_C_EXCEPTION - The value for the *what* parameter to :ctype:`Py_tracefunc` functions when a C + The value for the *what* parameter to :c:type:`Py_tracefunc` functions when a C function has raised an exception. -.. cvar:: int PyTrace_C_RETURN +.. c:var:: int PyTrace_C_RETURN - The value for the *what* parameter to :ctype:`Py_tracefunc` functions when a C + The value for the *what* parameter to :c:type:`Py_tracefunc` functions when a C function has returned. -.. cfunction:: void PyEval_SetProfile(Py_tracefunc func, PyObject *obj) +.. c:function:: void PyEval_SetProfile(Py_tracefunc func, PyObject *obj) Set the profiler function to *func*. The *obj* parameter is passed to the function as its first parameter, and may be any Python object, or *NULL*. If @@ -1028,13 +1044,13 @@ Python-level trace functions in previous versions. events. -.. cfunction:: void PyEval_SetTrace(Py_tracefunc func, PyObject *obj) +.. c:function:: void PyEval_SetTrace(Py_tracefunc func, PyObject *obj) Set the tracing function to *func*. This is similar to - :cfunc:`PyEval_SetProfile`, except the tracing function does receive line-number + :c:func:`PyEval_SetProfile`, except the tracing function does receive line-number events. -.. cfunction:: PyObject* PyEval_GetCallStats(PyObject *self) +.. c:function:: PyObject* PyEval_GetCallStats(PyObject *self) Return a tuple of function call counts. There are constants defined for the positions within the tuple: @@ -1086,25 +1102,25 @@ Advanced Debugger Support These functions are only intended to be used by advanced debugging tools. -.. cfunction:: PyInterpreterState* PyInterpreterState_Head() +.. c:function:: PyInterpreterState* PyInterpreterState_Head() Return the interpreter state object at the head of the list of all such objects. -.. cfunction:: PyInterpreterState* PyInterpreterState_Next(PyInterpreterState *interp) +.. c:function:: PyInterpreterState* PyInterpreterState_Next(PyInterpreterState *interp) Return the next interpreter state object after *interp* from the list of all such objects. -.. cfunction:: PyThreadState * PyInterpreterState_ThreadHead(PyInterpreterState *interp) +.. c:function:: PyThreadState * PyInterpreterState_ThreadHead(PyInterpreterState *interp) - Return the a pointer to the first :ctype:`PyThreadState` object in the list of + Return the a pointer to the first :c:type:`PyThreadState` object in the list of threads associated with the interpreter *interp*. -.. cfunction:: PyThreadState* PyThreadState_Next(PyThreadState *tstate) +.. c:function:: PyThreadState* PyThreadState_Next(PyThreadState *tstate) Return the next thread state object after *tstate* from the list of all such - objects belonging to the same :ctype:`PyInterpreterState` object. + objects belonging to the same :c:type:`PyInterpreterState` object. |