初期化 (initialization)、終了処理 (finalization)、スレッド
**********************************************************

See Python Initialization Configuration for details on how to
configure the interpreter prior to initialization.


Python 初期化以前
=================

Python が埋め込まれているアプリケーションでは、他の Python/C API 関数
を使う前に "Py_Initialize()" 関数を呼ばなければなりません。これには例
外として、いくつかの関数と グローバルな設定変数 があります。

次の関数は Python の初期化の前でも安全に呼び出せます:

* Functions that initialize the interpreter:

  * "Py_Initialize()"

  * "Py_InitializeEx()"

  * "Py_InitializeFromConfig()"

  * "Py_BytesMain()"

  * "Py_Main()"

  * the runtime pre-initialization functions covered in Python 初期化
    設定

* 設定関数:

  * "PyImport_AppendInittab()"

  * "PyImport_ExtendInittab()"

  * "PyInitFrozenExtensions()"

  * "PyMem_SetAllocator()"

  * "PyMem_SetupDebugHooks()"

  * "PyObject_SetArenaAllocator()"

  * "Py_SetProgramName()"

  * "Py_SetPythonHome()"

  * "PySys_ResetWarnOptions()"

  * the configuration functions covered in Python 初期化設定

* 情報取得の関数:

  * "Py_IsInitialized()"

  * "PyMem_GetAllocator()"

  * "PyObject_GetArenaAllocator()"

  * "Py_GetBuildInfo()"

  * "Py_GetCompiler()"

  * "Py_GetCopyright()"

  * "Py_GetPlatform()"

  * "Py_GetVersion()"

  * "Py_IsInitialized()"

* ユーティリティ:

  * "Py_DecodeLocale()"

  * the status reporting and utility functions covered in Python 初期
    化設定

* メモリアロケータ:

  * "PyMem_RawMalloc()"

  * "PyMem_RawRealloc()"

  * "PyMem_RawCalloc()"

  * "PyMem_RawFree()"

* Synchronization:

  * "PyMutex_Lock()"

  * "PyMutex_Unlock()"

注釈:

  Despite their apparent similarity to some of the functions listed
  above, the following functions **should not be called** before the
  interpreter has been initialized: "Py_EncodeLocale()",
  "Py_GetPath()", "Py_GetPrefix()", "Py_GetExecPrefix()",
  "Py_GetProgramFullPath()", "Py_GetPythonHome()",
  "Py_GetProgramName()", "PyEval_InitThreads()", and "Py_RunMain()".


グローバルな設定変数
====================

Python には、様々な機能やオプションを制御するグローバルな設定のための
変数があります。 デフォルトでは、これらのフラグは コマンドラインオプシ
ョン で制御されます。

オプションでフラグがセットされると、フラグの値はそのオプションがセット
された回数になります。 例えば、 "-b" では "Py_BytesWarningFlag" が 1
に設定され、 "-bb" では "Py_BytesWarningFlag" が 2 に設定されます。

int Py_BytesWarningFlag

   This API is kept for backward compatibility: setting
   "PyConfig.bytes_warning" should be used instead, see Python
   Initialization Configuration.

   "bytes" または "bytearray" を "str" と比較した場合、または、
   "bytes" を "int" と比較した場合に警告を発生させます。 "2" 以上の値
   を設定している場合は、エラーを発生させます。

   "-b" オプションで設定します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_DebugFlag

   This API is kept for backward compatibility: setting
   "PyConfig.parser_debug" should be used instead, see Python
   Initialization Configuration.

   パーサーのデバッグ出力を有効にします。(専門家専用です。コンパイルオ
   プションに依存します)。

   "-d" オプションと "PYTHONDEBUG" 環境変数で設定します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_DontWriteBytecodeFlag

   This API is kept for backward compatibility: setting
   "PyConfig.write_bytecode" should be used instead, see Python
   Initialization Configuration.

   非ゼロに設定した場合、Python はソースモジュールのインポート時に
   ".pyc" ファイルの作成を試みません。

   "-B" オプションと "PYTHONDONTWRITEBYTECODE" 環境変数で設定します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_FrozenFlag

   This API is kept for backward compatibility: setting
   "PyConfig.pathconfig_warnings" should be used instead, see Python
   Initialization Configuration.

   "Py_GetPath()" の中でモジュール検索パスを割り出しているときのエラー
   メッセージを抑制します。

   "_freeze_module" プログラムと "frozenmain" プログラムが使用する非公
   開フラグです。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_HashRandomizationFlag

   This API is kept for backward compatibility: setting
   "PyConfig.hash_seed" and "PyConfig.use_hash_seed" should be used
   instead, see Python Initialization Configuration.

   "PYTHONHASHSEED" 環境変数が空でない文字列に設定された場合に、 "1"
   が設定されます。

   フラグがゼロでない場合、 "PYTHONHASHSEED" 環境変数を読みシークレッ
   トハッシュシードを初期化します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_IgnoreEnvironmentFlag

   This API is kept for backward compatibility: setting
   "PyConfig.use_environment" should be used instead, see Python
   Initialization Configuration.

   Ignore all "PYTHON*" environment variables, e.g. "PYTHONPATH" and
   "PYTHONHOME", that might be set.

   "-E" オプションと "-I" オプションで設定します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_InspectFlag

   This API is kept for backward compatibility: setting
   "PyConfig.inspect" should be used instead, see Python
   Initialization Configuration.

   最初の引数にスクリプトが指定されたときや "-c" オプションが利用され
   た際に、 "sys.stdin" がターミナルに出力されないときであっても、スク
   リプトかコマンドを実行した後にインタラクティブモードに入ります。

   "-i" オプションと "PYTHONINSPECT" 環境変数で設定します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_InteractiveFlag

   This API is kept for backward compatibility: setting
   "PyConfig.interactive" should be used instead, see Python
   Initialization Configuration.

   "-i" オプションで設定します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_IsolatedFlag

   This API is kept for backward compatibility: setting
   "PyConfig.isolated" should be used instead, see Python
   Initialization Configuration.

   Python を隔離モードで実行します。 隔離モードでは "sys.path" はスク
   リプトのディレクトリやユーザのサイトパッケージのディレクトリを含み
   ません。

   "-I" オプションで設定します。

   Added in version 3.4.

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_LegacyWindowsFSEncodingFlag

   This API is kept for backward compatibility: setting
   "PyPreConfig.legacy_windows_fs_encoding" should be used instead,
   see Python Initialization Configuration.

   If the flag is non-zero, use the "mbcs" encoding with "replace"
   error handler, instead of the UTF-8 encoding with "surrogatepass"
   error handler, for the *filesystem encoding and error handler*.

   "PYTHONLEGACYWINDOWSFSENCODING" 環境変数が空でない文字列に設定され
   た場合に、 "1" に設定されます。

   より詳しくは **PEP 529** を参照してください。

   Availability: Windows.

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_LegacyWindowsStdioFlag

   This API is kept for backward compatibility: setting
   "PyConfig.legacy_windows_stdio" should be used instead, see Python
   Initialization Configuration.

   If the flag is non-zero, use "io.FileIO" instead of
   "io._WindowsConsoleIO" for "sys" standard streams.

   "PYTHONLEGACYWINDOWSSTDIO" 環境変数が空でない文字列に設定された場合
   に、 "1" に設定されます。

   より詳しくは **PEP 528** を参照してください。

   Availability: Windows.

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_NoSiteFlag

   This API is kept for backward compatibility: setting
   "PyConfig.site_import" should be used instead, see Python
   Initialization Configuration.

   "site" モジュールの import と、そのモジュールが行なっていた site ご
   との "sys.path" への操作を無効にします。後で "site" を明示的に
   import しても、これらの操作は実行されません (実行したい場合は、
   "site.main()" を呼び出してください)。

   "-S" オプションで設定します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_NoUserSiteDirectory

   This API is kept for backward compatibility: setting
   "PyConfig.user_site_directory" should be used instead, see Python
   Initialization Configuration.

   "ユーザのサイトパッケージのディレクトリ" を "sys.path" に追加しませ
   ん。

   "-s" オプション、 "-I" 、 "PYTHONNOUSERSITE" 環境変数で設定します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_OptimizeFlag

   This API is kept for backward compatibility: setting
   "PyConfig.optimization_level" should be used instead, see Python
   Initialization Configuration.

   "-O" オプションと "PYTHONOPTIMIZE" 環境変数で設定します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_QuietFlag

   This API is kept for backward compatibility: setting
   "PyConfig.quiet" should be used instead, see Python Initialization
   Configuration.

   インタラクティブモードでも copyright とバージョンのメッセージを表示
   しません。

   "-q" オプションで設定します。

   Added in version 3.2.

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_UnbufferedStdioFlag

   This API is kept for backward compatibility: setting
   "PyConfig.buffered_stdio" should be used instead, see Python
   Initialization Configuration.

   標準出力と標準エラーをバッファリングしないように強制します。

   "-u" オプションと "PYTHONUNBUFFERED" 環境変数で設定します。

   Deprecated since version 3.12, will be removed in version 3.15.

int Py_VerboseFlag

   This API is kept for backward compatibility: setting
   "PyConfig.verbose" should be used instead, see Python
   Initialization Configuration.

   モジュールが初期化されるたびにメッセージを出力し、それがどこ (ファ
   イル名やビルトインモジュール) からロードされたのかを表示します。 値
   が 2 以上の場合は、モジュールを検索するときにチェックしたファイルご
   とにメッセージを出力します。また、終了時のモジュールクリーンアップ
   に関する情報も提供します。

   "-v" オプションと "PYTHONVERBOSE" 環境変数で設定します。

   Deprecated since version 3.12, will be removed in version 3.15.


インタープリタの初期化と終了処理
================================

void Py_Initialize()
    * 次に属します: Stable ABI.*

   Python インタープリタを初期化します。 Python の埋め込みを行うアプリ
   ケーションでは、他のあらゆる Python/C API を使用するよりも前にこの
   関数を呼び出さなければなりません。いくつかの例外については Python
   初期化以前 を参照してください。

   This initializes the table of loaded modules ("sys.modules"), and
   creates the fundamental modules "builtins", "__main__" and "sys".
   It also initializes the module search path ("sys.path"). It does
   not set "sys.argv"; use the Python Initialization Configuration API
   for that. This is a no-op when called for a second time (without
   calling "Py_FinalizeEx()" first).  There is no return value; it is
   a fatal error if the initialization fails.

   Use "Py_InitializeFromConfig()" to customize the Python
   Initialization Configuration.

   注釈:

     Windows では "O_TEXT" から "O_BINARY" へコンソールモードが変更さ
     れますが、これはその C ランタイムを使っているコンソールでの
     Python 以外の使い勝手にも影響を及ぼします。

void Py_InitializeEx(int initsigs)
    * 次に属します: Stable ABI.*

   This function works like "Py_Initialize()" if *initsigs* is "1". If
   *initsigs* is "0", it skips initialization registration of signal
   handlers, which may be useful when CPython is embedded as part of a
   larger application.

   Use "Py_InitializeFromConfig()" to customize the Python
   Initialization Configuration.

PyStatus Py_InitializeFromConfig(const PyConfig *config)

   Initialize Python from *config* configuration, as described in
   Initialization with PyConfig.

   See the Python 初期化設定 section for details on pre-initializing
   the interpreter, populating the runtime configuration structure,
   and querying the returned status structure.

int Py_IsInitialized()
    * 次に属します: Stable ABI.*

   Python インタプリタが初期化済みであれば真(非ゼロ)を、さもなければ偽
   (ゼロ)を返します。"Py_FinalizeEx()" を呼び出した後は、
   "Py_Initialize()" を再び呼び出すまで、この関数は偽を返します。

int Py_IsFinalizing()
    * 次に属します: Stable ABI (バージョン 3.13 より).*

   Return true (non-zero) if the main Python interpreter is *shutting
   down*. Return false (zero) otherwise.

   Added in version 3.13.

int Py_FinalizeEx()
    * 次に属します: Stable ABI (バージョン 3.6 より).*

   Undo all initializations made by "Py_Initialize()" and subsequent
   use of Python/C API functions, and destroy all sub-interpreters
   (see "Py_NewInterpreter()" below) that were created and not yet
   destroyed since the last call to "Py_Initialize()".  This is a no-
   op when called for a second time (without calling "Py_Initialize()"
   again first).

   Since this is the reverse of "Py_Initialize()", it should be called
   in the same thread with the same interpreter active.  That means
   the main thread and the main interpreter. This should never be
   called while "Py_RunMain()" is running.

   Normally the return value is "0". If there were errors during
   finalization (flushing buffered data), "-1" is returned.

   Note that Python will do a best effort at freeing all memory
   allocated by the Python interpreter.  Therefore, any C-Extension
   should make sure to correctly clean up all of the preveiously
   allocated PyObjects before using them in subsequent calls to
   "Py_Initialize()".  Otherwise it could introduce vulnerabilities
   and incorrect behavior.

   この関数が提供されている理由はいくつかあります。Python の埋め込みを
   行っているアプリケーションでは、アプリケーションを再起動することな
   く Python を再起動したいことがあります。また、動的ロード可能イブラ
   リ (あるいは DLL) から Python インタプリタをロードするアプリケーシ
   ョンでは、DLL をアンロードする前に Python が確保したメモリを全て解
   放したいと考えるかもしれません。アプリケーション内で起きているメモ
   リリークを追跡する際に、開発者は Python が確保したメモリをアプリケ
   ーションの終了前に解放させたいと思う場合もあります。

   **Bugs and caveats:** The destruction of modules and objects in
   modules is done in random order; this may cause destructors
   ("__del__()" methods) to fail when they depend on other objects
   (even functions) or modules.  Dynamically loaded extension modules
   loaded by Python are not unloaded.  Small amounts of memory
   allocated by the Python interpreter may not be freed (if you find a
   leak, please report it).  Memory tied up in circular references
   between objects is not freed.  Interned strings will all be
   deallocated regardless of their reference count. 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
   "Py_Initialize()" and "Py_FinalizeEx()" more than once.
   "Py_FinalizeEx()" must not be called recursively from within
   itself.  Therefore, it must not be called by any code that may be
   run as part of the interpreter shutdown process, such as "atexit"
   handlers, object finalizers, or any code that may be run while
   flushing the stdout and stderr files.

   引数無しで 監査イベント "cpython._PySys_ClearAuditHooks" を送出しま
   す。

   Added in version 3.6.

void Py_Finalize()
    * 次に属します: Stable ABI.*

   この関数は "Py_FinalizeEx()" の後方互換性バージョンで、戻り値があり
   ません。

int Py_BytesMain(int argc, char **argv)
    * 次に属します: Stable ABI (バージョン 3.8 より).*

   Similar to "Py_Main()" but *argv* is an array of bytes strings,
   allowing the calling application to delegate the text decoding step
   to the CPython runtime.

   Added in version 3.8.

int Py_Main(int argc, wchar_t **argv)
    * 次に属します: Stable ABI.*

   The main program for the standard interpreter, encapsulating a full
   initialization/finalization cycle, as well as additional behaviour
   to implement reading configurations settings from the environment
   and command line, and then executing "__main__" in accordance with
   コマンドライン.

   This is made available for programs which wish to support the full
   CPython command line interface, rather than just embedding a Python
   runtime in a larger application.

   The *argc* and *argv* parameters are similar to those which are
   passed to a C program's "main()" function, except that the *argv*
   entries are first converted to "wchar_t" using "Py_DecodeLocale()".
   It is also important to note that the argument list entries may be
   modified to point to strings other than those passed in (however,
   the contents of the strings pointed to by the argument list are not
   modified).

   The return value is "2" if the argument list does not represent a
   valid Python command line, and otherwise the same as
   "Py_RunMain()".

   In terms of the CPython runtime configuration APIs documented in
   the runtime configuration section (and without accounting for error
   handling), "Py_Main" is approximately equivalent to:

      PyConfig config;
      PyConfig_InitPythonConfig(&config);
      PyConfig_SetArgv(&config, argc, argv);
      Py_InitializeFromConfig(&config);
      PyConfig_Clear(&config);

      Py_RunMain();

   In normal usage, an embedding application will call this function
   *instead* of calling "Py_Initialize()", "Py_InitializeEx()" or
   "Py_InitializeFromConfig()" directly, and all settings will be
   applied as described elsewhere in this documentation. If this
   function is instead called *after* a preceding runtime
   initialization API call, then exactly which environmental and
   command line configuration settings will be updated is version
   dependent (as it depends on which settings correctly support being
   modified after they have already been set once when the runtime was
   first initialized).

int Py_RunMain(void)

   Executes the main module in a fully configured CPython runtime.

   Executes the command ("PyConfig.run_command"), the script
   ("PyConfig.run_filename") or the module ("PyConfig.run_module")
   specified on the command line or in the configuration. If none of
   these values are set, runs the interactive Python prompt (REPL)
   using the "__main__" module's global namespace.

   If "PyConfig.inspect" is not set (the default), the return value
   will be "0" if the interpreter exits normally (that is, without
   raising an exception), the exit status of an unhandled
   "SystemExit", or "1" for any other unhandled exception.

   If "PyConfig.inspect" is set (such as when the "-i" option is
   used), rather than returning when the interpreter exits, execution
   will instead resume in an interactive Python prompt (REPL) using
   the "__main__" module's global namespace. If the interpreter exited
   with an exception, it is immediately raised in the REPL session.
   The function return value is then determined by the way the *REPL
   session* terminates: "0", "1", or the status of a "SystemExit", as
   specified above.

   This function always finalizes the Python interpreter before it
   returns.

   See Python Configuration for an example of a customized Python that
   always runs in isolated mode using "Py_RunMain()".

int PyUnstable_AtExit(PyInterpreterState *interp, void (*func)(void*), void *data)

   *これは Unstable APIです。マイナーリリースで予告なく変更されること
   があります。*

   Register an "atexit" callback for the target interpreter *interp*.
   This is similar to "Py_AtExit()", but takes an explicit interpreter
   and data pointer for the callback.

   There must be an *attached thread state* for *interp*.

   Added in version 3.13.


プロセスワイドのパラメータ
==========================

void Py_SetProgramName(const wchar_t *name)
    * 次に属します: Stable ABI.*

   This API is kept for backward compatibility: setting
   "PyConfig.program_name" should be used instead, see Python
   Initialization Configuration.

   この関数を呼び出すなら、最初に "Py_Initialize()" を呼び出すよりも前
   に呼び出さなければなりません。この関数はインタプリタにプログラムの
   "main()" 関数に指定した "argv[0]" 引数の値を教えます (ワイドキャラ
   クタに変換されます)。この引数値は、 "Py_GetPath()" や、以下に示すそ
   の他の関数が、インタプリタの実行可能形式から Python ランタイムライ
   ブラリへの相対パスを取得するために使われます。デフォルトの値は
   "'python'" です。引数はゼロ終端されたワイドキャラクタ文字列で、静的
   な記憶領域に入っていなければならず、その内容はプログラムの実行中に
   変更してはなりません。 Python インタプリタ内のコードで、この記憶領
   域の内容を変更するものは一切ありません。

   Use "Py_DecodeLocale()" to decode a bytes string to get a wchar_t*
   string.

   Deprecated since version 3.11, will be removed in version 3.15.

wchar_t *Py_GetProgramName()
    * 次に属します: Stable ABI.*

   Return the program name set with "PyConfig.program_name", or the
   default. The returned string points into static storage; the caller
   should not modify its value.

   This function should not be called before "Py_Initialize()",
   otherwise it returns "NULL".

   バージョン 3.10 で変更: It now returns "NULL" if called before
   "Py_Initialize()".

   Deprecated since version 3.13, will be removed in version 3.15: Use
   "PyConfig_Get("executable")" ("sys.executable") instead.

wchar_t *Py_GetPrefix()
    * 次に属します: Stable ABI.*

   Return the *prefix* for installed platform-independent files. This
   is derived through a number of complicated rules from the program
   name set with "PyConfig.program_name" 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 **prefix** variable in
   the top-level "Makefile" and the "--prefix" argument to the
   **configure** script at build time.  The value is available to
   Python code as "sys.base_prefix". It is only useful on Unix.  See
   also the next function.

   This function should not be called before "Py_Initialize()",
   otherwise it returns "NULL".

   バージョン 3.10 で変更: It now returns "NULL" if called before
   "Py_Initialize()".

   Deprecated since version 3.13, will be removed in version 3.15: Use
   "PyConfig_Get("base_prefix")" ("sys.base_prefix") instead. Use
   "PyConfig_Get("prefix")" ("sys.prefix") if virtual environments
   need to be handled.

wchar_t *Py_GetExecPrefix()
    * 次に属します: Stable ABI.*

   Return the *exec-prefix* for installed platform-*dependent* files.
   This is derived through a number of complicated rules from the
   program name set with "PyConfig.program_name" 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 **exec_prefix** variable
   in the top-level "Makefile" and the "--exec-prefix" argument to the
   **configure** script at build  time.  The value is available to
   Python code as "sys.base_exec_prefix".  It is only useful on Unix.

   背景: プラットフォーム依存のファイル (実行形式や共有ライブラリ) が
   別のディレクトリツリー内にインストールされている場合、 exec-prefix
   は prefix と異なります。典型的なインストール形態では、プラットフォ
   ーム非依存のファイルが "/usr/local" に収められる一方、プラットフォ
   ーム依存のファイルは "/usr/local/plat" サブツリーに収められます。

   一般的に、プラットフォームとは、ハードウェアとソフトウェアファミリ
   の組み合わせを指します。例えば、Solaris 2.x を動作させている Sparc
   マシンは全て同じプラットフォームであるとみなしますが、Solaris 2.x
   を動作させている Intel マシンは違うプラットフォームになりますし、同
   じ Intel マシンでも Linux を動作させているならまた別のプラットフォ
   ームです。一般的には、同じオペレーティングシステムでも、メジャーリ
   ビジョンの違うものは異なるプラットフォームです。非 Unix のオペレー
   ティングシステムの場合は話はまた別です; 非 Unix のシステムでは、イ
   ンストール方法はとても異なっていて、prefix や exec-prefix には意味
   がなく、空文字列が設定されています。コンパイル済みの Python バイト
   コードはプラットフォームに依存しないので注意してください (ただし、
   どのバージョンの Python でコンパイルされたかには依存します!)。

   システム管理者は、 **mount** や **automount** プログラムを使って、
   各プラットフォーム用の "/usr/local/plat" を異なったファイルシステム
   に置き、プラットフォーム間で "/usr/local" を共有するための設定方法
   を知っているでしょう。

   This function should not be called before "Py_Initialize()",
   otherwise it returns "NULL".

   バージョン 3.10 で変更: It now returns "NULL" if called before
   "Py_Initialize()".

   Deprecated since version 3.13, will be removed in version 3.15: Use
   "PyConfig_Get("base_exec_prefix")" ("sys.base_exec_prefix")
   instead. Use "PyConfig_Get("exec_prefix")" ("sys.exec_prefix") if
   virtual environments need to be handled.

wchar_t *Py_GetProgramFullPath()
    * 次に属します: Stable ABI.*

   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 "PyConfig.program_name"). The
   returned string points into static storage; the caller should not
   modify its value.  The value is available to Python code as
   "sys.executable".

   This function should not be called before "Py_Initialize()",
   otherwise it returns "NULL".

   バージョン 3.10 で変更: It now returns "NULL" if called before
   "Py_Initialize()".

   Deprecated since version 3.13, will be removed in version 3.15: Use
   "PyConfig_Get("executable")" ("sys.executable") instead.

wchar_t *Py_GetPath()
    * 次に属します: Stable ABI.*

   Return the default module search path; this is computed from the
   program name (set by "PyConfig.program_name") 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 macOS, "';'" on Windows.
   The returned string points into static storage; the caller should
   not modify its value.  The list "sys.path" is initialized with this
   value on interpreter startup; it can be (and usually is) modified
   later to change the search path for loading modules.

   This function should not be called before "Py_Initialize()",
   otherwise it returns "NULL".

   バージョン 3.10 で変更: It now returns "NULL" if called before
   "Py_Initialize()".

   Deprecated since version 3.13, will be removed in version 3.15: Use
   "PyConfig_Get("module_search_paths")" ("sys.path") instead.

const char *Py_GetVersion()
    * 次に属します: Stable ABI.*

   Python インタプリタのバージョンを返します。バージョンは、次のような
   形式の文字列です

      "3.0a5+ (py3k:63103M, May 12 2008, 00:53:55) \n[GCC 4.2.3]"

   第一ワード (最初のスペース文字まで) は、現在の Python のバージョン
   です; 最初の文字は、ピリオドで区切られたメジャーバージョンとマイナ
   ーバージョンです。関数が返す文字列ポインタは静的な記憶領域を返しま
   す; 関数の呼び出し側はこの値を変更できません。この値は Python コー
   ドからは "sys.version" として利用できます。

   See also the "Py_Version" constant.

const char *Py_GetPlatform()
    * 次に属します: Stable ABI.*

   現在のプラットフォームのプラットフォーム識別文字列を返します。Unix
   では、オペレーティングシステムの "公式の" 名前を小文字に変換し、後
   ろにメジャーリビジョン番号を付けた構成になっています。例えば
   Solaris 2.x は、SunOS 5.x, としても知られていますが、"'sunos5'" に
   なります。macOS では "'darwin'" です。Windows では "'win'" です。関
   数が返す文字列ポインタは静的な記憶領域を返します; 関数の呼び出し側
   はこの値を変更できません。この値は Python コードからは
   "sys.platform" として利用できます。

const char *Py_GetCopyright()
    * 次に属します: Stable ABI.*

   現在の Python バージョンに対する公式の著作権表示文字列を返します。
   例えば

   "'Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam'"

   関数が返す文字列ポインタは静的な記憶領域を返します; 関数の呼び出し
   側はこの値を変更できません。この値は Python コードからは
   "sys.copyright" として利用できます。

const char *Py_GetCompiler()
    * 次に属します: Stable ABI.*

   現在使っているバージョンの Python をビルドする際に用いたコンパイラ
   を示す文字列を、角括弧で囲った文字列を返します。例えば:

      "[GCC 2.7.2.2]"

   関数が返す文字列ポインタは静的な記憶領域を返します; 関数の呼び出し
   側はこの値を変更できません。この値は Python コードからは
   "sys.version" の一部として取り出せます。

const char *Py_GetBuildInfo()
    * 次に属します: Stable ABI.*

   現在使っている Python インタプリタインスタンスの、シーケンス番号と
   ビルド日時に関する情報を返します。例えば

      "#67, Aug  1 1997, 22:34:28"

   関数が返す文字列ポインタは静的な記憶領域を返します; 関数の呼び出し
   側はこの値を変更できません。この値は Python コードからは
   "sys.version" の一部として取り出せます。

void PySys_SetArgvEx(int argc, wchar_t **argv, int updatepath)
    * 次に属します: Stable ABI.*

   This API is kept for backward compatibility: setting
   "PyConfig.argv", "PyConfig.parse_argv" and "PyConfig.safe_path"
   should be used instead, see Python Initialization Configuration.

   *argc* および *argv* に基づいて "sys.argv" を設定します。これらの引
   数はプログラムの "main()" に渡した引数に似ていますが、最初の要素が
   Python インタプリタの宿主となっている実行形式の名前ではなく、実行さ
   れるスクリプト名を参照しなければならない点が違います。実行するスク
   リプトがない場合、 *argv* の最初の要素は空文字列にしてもかまいませ
   ん。この関数が "sys.argv" の初期化に失敗した場合、致命的エラーを
   "Py_FatalError()" で知らせます。

   *updatepath* が 0 の場合、ここまでの動作がこの関数がすることの全て
   です。 *updatepath* が 0 でない場合、この関数は "sys.path" を以下の
   アルゴリズムに基づいて修正します:

   * 存在するスクリプトの名前が "argv[0]" に渡された場合、そのスクリプ
     トがある場所の絶対パスを "sys.path" の先頭に追加します。

   * それ以外の場合 (*argc* が "0" だったり、 "argv[0]" が存在するファ
     イル名を指していない場合)、 "sys.path" の先頭に空の文字列を追加し
     ます。 これは現在の作業ディレクトリ (""."") を先頭に追加するのと
     同じです。

   Use "Py_DecodeLocale()" to decode a bytes string to get a wchar_t*
   string.

   See also "PyConfig.orig_argv" and "PyConfig.argv" members of the
   Python Initialization Configuration.

   注釈:

     It is recommended that applications embedding the Python
     interpreter for purposes other than executing a single script
     pass "0" as *updatepath*, and update "sys.path" themselves if
     desired. See **CVE 2008-5983**.3.1.3 より前のバージョンでは、
     "PySys_SetArgv()" の呼び出しが完了した後に "sys.path" の先頭の要
     素を取り出すことで、同じ効果が得られます。例えばこのように使いま
     す:

        PyRun_SimpleString("import sys; sys.path.pop(0)\n");

   Added in version 3.1.3.

   Deprecated since version 3.11, will be removed in version 3.15.

void PySys_SetArgv(int argc, wchar_t **argv)
    * 次に属します: Stable ABI.*

   This API is kept for backward compatibility: setting
   "PyConfig.argv" and "PyConfig.parse_argv" should be used instead,
   see Python Initialization Configuration.

   この関数は、 **python** インタプリタが "-I" オプション付きで実行さ
   れている場合を除き "PySys_SetArgvEx()" の *updatepath* に "1" を設
   定したのと同じように動作します。

   Use "Py_DecodeLocale()" to decode a bytes string to get a wchar_t*
   string.

   See also "PyConfig.orig_argv" and "PyConfig.argv" members of the
   Python Initialization Configuration.

   バージョン 3.4 で変更: *updatepath* の値は "-I" オプションに依存し
   ます。

   Deprecated since version 3.11, will be removed in version 3.15.

void Py_SetPythonHome(const wchar_t *home)
    * 次に属します: Stable ABI.*

   This API is kept for backward compatibility: setting
   "PyConfig.home" should be used instead, see Python Initialization
   Configuration.

   Python の標準ライブラリがある、デフォルトの "home" ディレクトリを設
   定します。引数の文字列の意味については "PYTHONHOME" を参照してくだ
   さい。

   引数は静的なストレージに置かれてプログラム実行中に書き換えられない
   ようなゼロ終端の文字列であるべきです。Python インタプリタはこのスト
   レージの内容を変更しません。

   Use "Py_DecodeLocale()" to decode a bytes string to get a wchar_t*
   string.

   Deprecated since version 3.11, will be removed in version 3.15.

wchar_t *Py_GetPythonHome()
    * 次に属します: Stable ABI.*

   Return the default "home", that is, the value set by
   "PyConfig.home", or the value of the "PYTHONHOME" environment
   variable if it is set.

   This function should not be called before "Py_Initialize()",
   otherwise it returns "NULL".

   バージョン 3.10 で変更: It now returns "NULL" if called before
   "Py_Initialize()".

   Deprecated since version 3.13, will be removed in version 3.15: Use
   "PyConfig_Get("home")" or the "PYTHONHOME" environment variable
   instead.


スレッド状態 (thread state) とグローバルインタプリタロック (global interpreter lock)
====================================================================================

Unless on a *free-threaded* build of *CPython*, the Python interpreter
is not fully thread-safe.  In order to support multi-threaded Python
programs, there's a global lock, called the *global interpreter lock*
or *GIL*, that must be held by the current thread before it can safely
access Python objects. Without the lock, even the simplest 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.

このため、 *GIL* を獲得したスレッドだけが Python オブジェクトを操作し
たり、 Python/C API 関数を呼び出したりできるというルールがあります。並
行処理をエミュレートするために、インタプリタは定期的にロックを解放した
り獲得したりします。 ("sys.setswitchinterval()" を参照) このロックはブ
ロックが起こりうる I/O 操作の付近でも解放・獲得され、 I/O を要求するス
レッドが I/O 操作の完了を待つ間、他のスレッドが動作できるようにしてい
ます。

The Python interpreter keeps some thread-specific bookkeeping
information inside a data structure called "PyThreadState", known as a
*thread state*. Each OS thread has a thread-local pointer to a
"PyThreadState"; a thread state referenced by this pointer is
considered to be *attached*.

A thread can only have one *attached thread state* at a time. An
attached thread state is typically analogous with holding the *GIL*,
except on *free-threaded* builds.  On builds with the *GIL* enabled,
*attaching* a thread state will block until the *GIL* can be acquired.
However,  even on builds with the *GIL* disabled, it is still required
to have an attached thread state to call most of the C API.

In general, there will always be an *attached thread state* when using
Python's C API. Only in some specific cases (such as in a
"Py_BEGIN_ALLOW_THREADS" block) will the thread not have an attached
thread state. If uncertain, check if "PyThreadState_GetUnchecked()"
returns "NULL".


Detaching the thread state from extension code
----------------------------------------------

Most extension code manipulating the *thread state* has the following
simple structure:

   Save the thread state in a local variable.
   ... Do some blocking I/O operation ...
   Restore the thread state from the local variable.

この構造は非常に一般的なので、作業を単純にするために2つのマクロが用意
されています:

   Py_BEGIN_ALLOW_THREADS
   ... Do some blocking I/O operation ...
   Py_END_ALLOW_THREADS

"Py_BEGIN_ALLOW_THREADS" マクロは新たなブロックを開始し、隠しローカル
変数を宣言します; "Py_END_ALLOW_THREADS" はブロックを閉じます。

上のブロックは次のコードに展開されます:

   PyThreadState *_save;

   _save = PyEval_SaveThread();
   ... Do some blocking I/O operation ...
   PyEval_RestoreThread(_save);

Here is how these functions work:

The *attached thread state* holds the *GIL* for the entire
interpreter. When detaching the *attached thread state*, the *GIL* is
released, allowing other threads to attach a thread state to their own
thread, thus getting the *GIL* and can start executing. The pointer to
the prior *attached thread state* is stored as a local variable. Upon
reaching "Py_END_ALLOW_THREADS", the thread state that was previously
*attached* is passed to "PyEval_RestoreThread()". This function will
block until another releases its *thread state*, thus allowing the old
*thread state* to get re-attached and the C API can be called again.

For *free-threaded* builds, the *GIL* is normally out of the question,
but detaching the *thread state* is still required for blocking I/O
and long operations. The difference is that threads don't have to wait
for the *GIL* to be released to attach their thread state, allowing
true multi-core parallelism.

注釈:

  Calling system I/O functions is the most common use case for
  detaching the *thread state*, but it can also be useful before
  calling long-running computations which don't need access to Python
  objects, such as compression or cryptographic functions operating
  over memory buffers. For example, the standard "zlib" and "hashlib"
  modules detach the *thread state* when compressing or hashing data.


Python 以外で作られたスレッド
-----------------------------

When threads are created using the dedicated Python APIs (such as the
"threading" module), a thread state is automatically associated to
them and the code showed above is therefore correct.  However, when
threads are created from C (for example by a third-party library with
its own thread management), they don't hold the *GIL*, because they
don't have an *attached thread state*.

If you need to call Python code from these threads (often this will be
part of a callback API provided by the aforementioned third-party
library), you must first register these threads with the interpreter
by creating an *attached thread state* before you can start using the
Python/C API.  When you are done, you should detach the *thread
state*, and finally free it.

"PyGILState_Ensure()" と "PyGILState_Release()" はこの処理を自動的に行
います。 Cのスレッドから Python を呼び出す典型的な方法は以下のとおりで
す:

   PyGILState_STATE gstate;
   gstate = PyGILState_Ensure();

   /* Perform Python actions here. */
   result = CallSomeFunction();
   /* evaluate result or handle exception */

   /* Release the thread. No Python API allowed beyond this point. */
   PyGILState_Release(gstate);

Note that the "PyGILState_*" functions assume there is only one global
interpreter (created automatically by "Py_Initialize()").  Python
supports the creation of additional interpreters (using
"Py_NewInterpreter()"), but mixing multiple interpreters and the
"PyGILState_*" API is unsupported. This is because
"PyGILState_Ensure()" and similar functions default to *attaching* a
*thread state* for the main interpreter, meaning that the thread can't
safely interact with the calling subinterpreter.


Supporting subinterpreters in non-Python threads
------------------------------------------------

If you would like to support subinterpreters with non-Python created
threads, you must use the "PyThreadState_*" API instead of the
traditional "PyGILState_*" API.

In particular, you must store the interpreter state from the calling
function and pass it to "PyThreadState_New()", which will ensure that
the *thread state* is targeting the correct interpreter:

   /* The return value of PyInterpreterState_Get() from the
      function that created this thread. */
   PyInterpreterState *interp = ThreadData->interp;
   PyThreadState *tstate = PyThreadState_New(interp);
   PyThreadState_Swap(tstate);

   /* GIL of the subinterpreter is now held.
      Perform Python actions here. */
   result = CallSomeFunction();
   /* evaluate result or handle exception */

   /* Destroy the thread state. No Python API allowed beyond this point. */
   PyThreadState_Clear(tstate);
   PyThreadState_DeleteCurrent();


Cautions about fork()
---------------------

Another important thing to note about threads is their behaviour in
the face of the C "fork()" call. On most systems with "fork()", after
a process forks only the thread that issued the fork will exist.  This
has a concrete impact both on how locks must be handled and on all
stored state in CPython's runtime.

The fact that only the "current" thread remains means any locks held
by other threads will never be released. Python solves this for
"os.fork()" by acquiring the locks it uses internally before the fork,
and releasing them afterwards. In addition, it resets any 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
"pthread_atfork()" would need to be used to accomplish the same thing.
Additionally, when extending or embedding Python, calling "fork()"
directly rather than through "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.
"PyOS_AfterFork_Child()" tries to reset the necessary locks, but is
not always able to.

The fact that all other threads go away also means that CPython's
runtime state there must be cleaned up properly, which "os.fork()"
does.  This means finalizing all other "PyThreadState" objects
belonging to the current interpreter and all other
"PyInterpreterState" objects.  Due to this and the special nature of
the "main" interpreter, "fork()" should only be called in that
interpreter's "main" thread, where the CPython global runtime was
originally initialized. The only exception is if "exec()" will be
called immediately after.


Cautions regarding runtime finalization
---------------------------------------

In the late stage of *interpreter shutdown*, after attempting to wait
for non-daemon threads to exit (though this can be interrupted by
"KeyboardInterrupt") and running the "atexit" functions, the runtime
is marked as *finalizing*: "Py_IsFinalizing()" and
"sys.is_finalizing()" return true.  At this point, only the
*finalization thread* that initiated finalization (typically the main
thread) is allowed to acquire the *GIL*.

If any thread, other than the finalization thread, attempts to attach
a *thread state* during finalization, either explicitly or implicitly,
the thread enters **a permanently blocked state** where it remains
until the program exits.  In most cases this is harmless, but this can
result in deadlock if a later stage of finalization attempts to
acquire a lock owned by the blocked thread, or otherwise waits on the
blocked thread.

Gross? Yes. This prevents random crashes and/or unexpectedly skipped
C++ finalizations further up the call stack when such threads were
forcibly exited here in CPython 3.13 and earlier. The CPython runtime
*thread state* C APIs have never had any error reporting or handling
expectations at *thread state* attachment time that would've allowed
for graceful exit from this situation. Changing that would require new
stable C APIs and rewriting the majority of C code in the CPython
ecosystem to use those with error handling.


高レベルAPI
-----------

C拡張を書いたりPythonインタプリタを埋め込むときに最も一般的に使われる
型や関数は次のとおりです:

type PyInterpreterState
    * 次に属します: Limited API (不透明な構造体として).*

   このデータ構造体は、協調動作する多数のスレッド間で共有されている状
   態を表現します。同じインタプリタに属するスレッドはモジュール管理情
   報やその他いくつかの内部的な情報を共有しています。この構造体には公
   開 (public) のメンバはありません。

   異なるインタプリタに属するスレッド間では、利用可能なメモリ、開かれ
   ているファイルデスクリプタなどといったプロセス状態を除いて、初期状
   態では何も共有されていません。GILもまた、スレッドがどのインタプリタ
   に属しているかに関わらずすべてのスレッドで共有されています。

   バージョン 3.12 で変更: **PEP 684** introduced the possibility of a
   per-interpreter GIL. See "Py_NewInterpreterFromConfig()".

type PyThreadState
    * 次に属します: Limited API (不透明な構造体として).*

   This data structure represents the state of a single thread.  The
   only public data member is:

   PyInterpreterState *interp

      This thread's interpreter state.

void PyEval_InitThreads()
    * 次に属します: Stable ABI.*

   Deprecated function which does nothing.

   In Python 3.6 and older, this function created the GIL if it didn't
   exist.

   バージョン 3.9 で変更: The function now does nothing.

   バージョン 3.7 で変更: この関数は "Py_Initialize()" から呼び出され
   るようになり、わざわざ呼び出す必要はもう無くなりました。

   バージョン 3.2 で変更: この関数は "Py_Initialize()" より前に呼び出
   すことができなくなりました。

   バージョン 3.9 で非推奨.

PyThreadState *PyEval_SaveThread()
    * 次に属します: Stable ABI.*

   Detach the *attached thread state* and return it. The thread will
   have no *thread state* upon returning.

void PyEval_RestoreThread(PyThreadState *tstate)
    * 次に属します: Stable ABI.*

   Set the *attached thread state* to *tstate*. The passed *thread
   state* **should not** be *attached*, otherwise deadlock ensues.
   *tstate* will be attached upon returning.

   注釈:

     Calling this function from a thread when the runtime is
     finalizing will hang the thread until the program exits, even if
     the thread was not created by Python.  Refer to Cautions
     regarding runtime finalization for more details.

   バージョン 3.14 で変更: Hangs the current thread, rather than
   terminating it, if called while the interpreter is finalizing.

PyThreadState *PyThreadState_Get()
    * 次に属します: Stable ABI.*

   Return the *attached thread state*. If the thread has no attached
   thread state, (such as when inside of "Py_BEGIN_ALLOW_THREADS"
   block), then this issues a fatal error (so that the caller needn't
   check for "NULL").

   See also "PyThreadState_GetUnchecked()".

PyThreadState *PyThreadState_GetUnchecked()

   Similar to "PyThreadState_Get()", but don't kill the process with a
   fatal error if it is NULL. The caller is responsible to check if
   the result is NULL.

   Added in version 3.13: In Python 3.5 to 3.12, the function was
   private and known as "_PyThreadState_UncheckedGet()".

PyThreadState *PyThreadState_Swap(PyThreadState *tstate)
    * 次に属します: Stable ABI.*

   Set the *attached thread state* to *tstate*, and return the *thread
   state* that was attached prior to calling.

   This function is safe to call without an *attached thread state*;
   it will simply return "NULL" indicating that there was no prior
   thread state.

   参考: "PyEval_ReleaseThread()"

   注釈:

     Similar to "PyGILState_Ensure()", this function will hang the
     thread if the runtime is finalizing.

以下の関数はスレッドローカルストレージを利用していて、サブインタプリタ
との互換性がありません:

type PyGILState_STATE
    * 次に属します: Stable ABI.*

   The type of the value returned by "PyGILState_Ensure()" and passed
   to "PyGILState_Release()".

   enumerator PyGILState_LOCKED

      The GIL was already held when "PyGILState_Ensure()" was called.

   enumerator PyGILState_UNLOCKED

      The GIL was not held when "PyGILState_Ensure()" was called.

PyGILState_STATE PyGILState_Ensure()
    * 次に属します: Stable ABI.*

   Ensure that the current thread is ready to call the Python C API
   regardless of the current state of Python, or of the *attached
   thread state*. This may be called as many times as desired by a
   thread as long as each call is matched with a call to
   "PyGILState_Release()". In general, other thread-related APIs may
   be used between "PyGILState_Ensure()" and "PyGILState_Release()"
   calls as long as the thread state is restored to its previous state
   before the Release().  For example, normal usage of the
   "Py_BEGIN_ALLOW_THREADS" and "Py_END_ALLOW_THREADS" macros is
   acceptable.

   The return value is an opaque "handle" to the *attached thread
   state* when "PyGILState_Ensure()" was called, and must be passed to
   "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 "PyGILState_Ensure()" must save the
   handle for its call to "PyGILState_Release()".

   When the function returns, there will be an *attached thread state*
   and the thread will be able to call arbitrary Python code.  Failure
   is a fatal error.

   警告:

     Calling this function when the runtime is finalizing is unsafe.
     Doing so will either hang the thread until the program ends, or
     fully crash the interpreter in rare cases. Refer to Cautions
     regarding runtime finalization for more details.

   バージョン 3.14 で変更: Hangs the current thread, rather than
   terminating it, if called while the interpreter is finalizing.

void PyGILState_Release(PyGILState_STATE)
    * 次に属します: Stable ABI.*

   獲得したすべてのリソースを解放します。この関数を呼び出すと、Python
   の状態は対応する "PyGILState_Ensure()" を呼び出す前と同じとなります
   (通常、この状態は呼び出し元でははわかりませんので、GILState APIを利
   用するようにしてください)。

   "PyGILState_Ensure()" を呼び出す場合は、必ず同一スレッド内で対応す
   る "PyGILState_Release()" を呼び出してください。

PyThreadState *PyGILState_GetThisThreadState()
    * 次に属します: Stable ABI.*

   Get the *attached thread state* for this thread.  May return "NULL"
   if no GILState API has been used on the current thread.  Note that
   the main thread always has such a thread-state, even if no auto-
   thread-state call has been made on the main thread.  This is mainly
   a helper/diagnostic function.

   注釈:

     This function may return non-"NULL" even when the *thread state*
     is detached. Prefer "PyThreadState_Get()" or
     "PyThreadState_GetUnchecked()" for most cases.

   参考: "PyThreadState_Get()"

int PyGILState_Check()

   Return "1" if the current thread is holding the *GIL* and "0"
   otherwise. This function can be called from any thread at any time.
   Only if it has had its *thread state* initialized via
   "PyGILState_Ensure()" will it return "1". This is mainly a
   helper/diagnostic function.  It can be useful for example in
   callback contexts or memory allocation functions when knowing that
   the *GIL* is locked can allow the caller to perform sensitive
   actions or otherwise behave differently.

   注釈:

     If the current Python process has ever created a subinterpreter,
     this function will *always* return "1". Prefer
     "PyThreadState_GetUnchecked()" for most cases.

   Added in version 3.4.

以下のマクロは、通常末尾にセミコロンを付けずに使います; Python ソース
配布物内の使用例を見てください。

Py_BEGIN_ALLOW_THREADS
    * 次に属します: Stable ABI.*

   このマクロを展開すると "{ PyThreadState *_save; _save =
   PyEval_SaveThread();" になります。マクロに開き波括弧が入っているこ
   とに注意してください; この波括弧は後で "Py_END_ALLOW_THREADS" マク
   ロと対応させなければなりません。マクロについての詳しい議論は上記を
   参照してください。

Py_END_ALLOW_THREADS
    * 次に属します: Stable ABI.*

   このマクロを展開すると "PyEval_RestoreThread(_save); }" になります
   。マクロに開き波括弧が入っていることに注意してください; この波括弧
   は事前の "Py_BEGIN_ALLOW_THREADS" マクロと対応していなければなりま
   せん。マクロについての詳しい議論は上記を参照してください。

Py_BLOCK_THREADS
    * 次に属します: Stable ABI.*

   このマクロを展開すると "PyEval_RestoreThread(_save);" になります:
   閉じ波括弧のない "Py_END_ALLOW_THREADS" と同じです。

Py_UNBLOCK_THREADS
    * 次に属します: Stable ABI.*

   このマクロを展開すると "_save = PyEval_SaveThread();" になります:
   開き波括弧のない "Py_BEGIN_ALLOW_THREADS" と同じです。


低レベルAPI
-----------

次の全ての関数は "Py_Initialize()" の後に呼び出さなければなりません。

バージョン 3.7 で変更: "Py_Initialize()" now initializes the *GIL* and
sets an *attached thread state*.

PyInterpreterState *PyInterpreterState_New()
    * 次に属します: Stable ABI.*

   Create a new interpreter state object.  An *attached thread state*
   is not needed, but may optionally exist if it is necessary to
   serialize calls to this function.

   引数無しで 監査イベント "cpython.PyInterpreterState_New" を送出しま
   す。

void PyInterpreterState_Clear(PyInterpreterState *interp)
    * 次に属します: Stable ABI.*

   Reset all information in an interpreter state object.  There must
   be an *attached thread state* for the interpreter.

   引数無しで 監査イベント "cpython.PyInterpreterState_Clear" を送出し
   ます。

void PyInterpreterState_Delete(PyInterpreterState *interp)
    * 次に属します: Stable ABI.*

   Destroy an interpreter state object.  There **should not** be an
   *attached thread state* for the target interpreter. The interpreter
   state must have been reset with a previous call to
   "PyInterpreterState_Clear()".

PyThreadState *PyThreadState_New(PyInterpreterState *interp)
    * 次に属します: Stable ABI.*

   Create a new thread state object belonging to the given interpreter
   object. An *attached thread state* is not needed.

void PyThreadState_Clear(PyThreadState *tstate)
    * 次に属します: Stable ABI.*

   Reset all information in a *thread state* object.  *tstate* must be
   *attached*

   バージョン 3.9 で変更: This function now calls the
   "PyThreadState.on_delete" callback. Previously, that happened in
   "PyThreadState_Delete()".

   バージョン 3.13 で変更: The "PyThreadState.on_delete" callback was
   removed.

void PyThreadState_Delete(PyThreadState *tstate)
    * 次に属します: Stable ABI.*

   Destroy a *thread state* object.  *tstate* should not be *attached*
   to any thread. *tstate* must have been reset with a previous call
   to "PyThreadState_Clear()".

void PyThreadState_DeleteCurrent(void)

   Detach the *attached thread state* (which must have been reset with
   a previous call to "PyThreadState_Clear()") and then destroy it.

   No *thread state* will be *attached* upon returning.

PyFrameObject *PyThreadState_GetFrame(PyThreadState *tstate)
    * 次に属します: Stable ABI (バージョン 3.10 より).*

   Get the current frame of the Python thread state *tstate*.

   Return a *strong reference*. Return "NULL" if no frame is currently
   executing.

   See also "PyEval_GetFrame()".

   *tstate* must not be "NULL", and must be *attached*.

   Added in version 3.9.

uint64_t PyThreadState_GetID(PyThreadState *tstate)
    * 次に属します: Stable ABI (バージョン 3.10 より).*

   Get the unique *thread state* identifier of the Python thread state
   *tstate*.

   *tstate* must not be "NULL", and must be *attached*.

   Added in version 3.9.

PyInterpreterState *PyThreadState_GetInterpreter(PyThreadState *tstate)
    * 次に属します: Stable ABI (バージョン 3.10 より).*

   Get the interpreter of the Python thread state *tstate*.

   *tstate* must not be "NULL", and must be *attached*.

   Added in version 3.9.

void PyThreadState_EnterTracing(PyThreadState *tstate)

   Suspend tracing and profiling in the Python thread state *tstate*.

   Resume them using the "PyThreadState_LeaveTracing()" function.

   Added in version 3.11.

void PyThreadState_LeaveTracing(PyThreadState *tstate)

   Resume tracing and profiling in the Python thread state *tstate*
   suspended by the "PyThreadState_EnterTracing()" function.

   See also "PyEval_SetTrace()" and "PyEval_SetProfile()" functions.

   Added in version 3.11.

int PyUnstable_ThreadState_SetStackProtection(PyThreadState *tstate, void *stack_start_addr, size_t stack_size)

   *これは Unstable APIです。マイナーリリースで予告なく変更されること
   があります。*

   Set the stack protection start address and stack protection size of
   a Python thread state.

   On success, return "0". On failure, set an exception and return
   "-1".

   CPython implements recursion control for C code by raising
   "RecursionError" when it notices that the machine execution stack
   is close to overflow. See for example the "Py_EnterRecursiveCall()"
   function. For this, it needs to know the location of the current
   thread's stack, which it normally gets from the operating system.
   When the stack is changed, for example using context switching
   techniques like the Boost library's "boost::context", you must call
   "PyUnstable_ThreadState_SetStackProtection()" to inform CPython of
   the change.

   Call "PyUnstable_ThreadState_SetStackProtection()" either before or
   after changing the stack. Do not call any other Python C API
   between the call and the stack change.

   See "PyUnstable_ThreadState_ResetStackProtection()" for undoing
   this operation.

   Added in version 3.14.1:

   警告:

     This function was added in a bugfix release, and extensions that
     use it will be incompatible with Python 3.14.0. Most packaging
     tools for Python are not able to handle this incompatibility
     automatically, and will need explicit configuration. When using
     PyPA standards (wheels and source distributions), specify
     "Requires-Python: != 3.14.0.*" in core metadata.

void PyUnstable_ThreadState_ResetStackProtection(PyThreadState *tstate)

   *これは Unstable APIです。マイナーリリースで予告なく変更されること
   があります。*

   Reset the stack protection start address and stack protection size
   of a Python thread state to the operating system defaults.

   See "PyUnstable_ThreadState_SetStackProtection()" for an
   explanation.

   Added in version 3.14.1:

   警告:

     This function was added in a bugfix release, and extensions that
     use it will be incompatible with Python 3.14.0. Most packaging
     tools for Python are not able to handle this incompatibility
     automatically, and will need explicit configuration. When using
     PyPA standards (wheels and source distributions), specify
     "Requires-Python: != 3.14.0.*" in core metadata.

PyInterpreterState *PyInterpreterState_Get(void)
    * 次に属します: Stable ABI (バージョン 3.9 より).*

   Get the current interpreter.

   Issue a fatal error if there no *attached thread state*. It cannot
   return NULL.

   Added in version 3.9.

int64_t PyInterpreterState_GetID(PyInterpreterState *interp)
    * 次に属します: Stable ABI (バージョン 3.7 より).*

   インタプリタの一意な ID を返します。 処理中に何かエラーが起きたら、
   "-1" が返され、エラーがセットされます。

   The caller must have an *attached thread state*.

   Added in version 3.7.

PyObject *PyInterpreterState_GetDict(PyInterpreterState *interp)
    *戻り値: 借用参照。** 次に属します: Stable ABI (バージョン 3.8 よ
   り).*

   インタプリタ固有のデータを保持している辞書を返します。 この関数が
   "NULL" を返した場合は、ここまでで例外は送出されておらず、呼び出し側
   はインタプリタ固有の辞書は利用できないと考えなければなりません。

   この関数は "PyModule_GetState()" を置き換えるものではなく、拡張モジ
   ュールがインタプリタ固有の状態情報を格納するのに使うべきものです。

   The returned dictionary is borrowed from the interpreter and is
   valid until interpreter shutdown.

   Added in version 3.8.

typedef PyObject *(*_PyFrameEvalFunction)(PyThreadState *tstate, _PyInterpreterFrame *frame, int throwflag)

   Type of a frame evaluation function.

   The *throwflag* parameter is used by the "throw()" method of
   generators: if non-zero, handle the current exception.

   バージョン 3.9 で変更: The function now takes a *tstate* parameter.

   バージョン 3.11 で変更: The *frame* parameter changed from
   "PyFrameObject*" to "_PyInterpreterFrame*".

_PyFrameEvalFunction _PyInterpreterState_GetEvalFrameFunc(PyInterpreterState *interp)

   Get the frame evaluation function.

   See the **PEP 523** "Adding a frame evaluation API to CPython".

   Added in version 3.9.

void _PyInterpreterState_SetEvalFrameFunc(PyInterpreterState *interp, _PyFrameEvalFunction eval_frame)

   Set the frame evaluation function.

   See the **PEP 523** "Adding a frame evaluation API to CPython".

   Added in version 3.9.

PyObject *PyThreadState_GetDict()
    *戻り値: 借用参照。** 次に属します: Stable ABI.*

   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 the dictionary.  It is okay to call this function
   when no *thread state* is *attached*. If this function returns
   "NULL", no exception has been raised and the caller should assume
   no thread state is attached.

int PyThreadState_SetAsyncExc(unsigned long id, PyObject *exc)
    * 次に属します: Stable ABI.*

   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 function does not steal any references to *exc*.
   To prevent naive misuse, you must write your own C extension to
   call this.  Must be called with an *attached thread state*. Returns
   the number of thread states modified; this is normally one, but
   will be zero if the thread id isn't found.  If *exc* is "NULL", the
   pending exception (if any) for the thread is cleared. This raises
   no exceptions.

   バージョン 3.7 で変更: *id* 引数の型が long から unsigned long へ変
   更されました。

void PyEval_AcquireThread(PyThreadState *tstate)
    * 次に属します: Stable ABI.*

   *Attach* *tstate* to the current thread, which must not be "NULL"
   or already *attached*.

   The calling thread must not already have an *attached thread
   state*.

   注釈:

     Calling this function from a thread when the runtime is
     finalizing will hang the thread until the program exits, even if
     the thread was not created by Python.  Refer to Cautions
     regarding runtime finalization for more details.

   バージョン 3.8 で変更: Updated to be consistent with
   "PyEval_RestoreThread()", "Py_END_ALLOW_THREADS()", and
   "PyGILState_Ensure()", and terminate the current thread if called
   while the interpreter is finalizing.

   バージョン 3.14 で変更: Hangs the current thread, rather than
   terminating it, if called while the interpreter is finalizing.

   "PyEval_RestoreThread()" はいつでも (スレッドが初期化されたいないと
   きでも) 利用可能な高レベル関数です。

void PyEval_ReleaseThread(PyThreadState *tstate)
    * 次に属します: Stable ABI.*

   Detach the *attached thread state*. The *tstate* argument, which
   must not be "NULL", is only used to check that it represents the
   *attached thread state* --- if it isn't, a fatal error is reported.

   "PyEval_SaveThread()" はより高レベルな関数で常に (スレッドが初期化
   されていないときでも) 利用できます。


サブインタプリタサポート
========================

ほとんどの場合は埋め込む Python インタプリタは1つだけですが、いくつか
の場合に同一プロセス内、あるいは同一スレッド内で、複数の独立したインタ
プリタを作成する必要があります。 これを可能にするのがサブインタプリタ
です。

"メイン" インタプリタとは、ランタイムが初期化を行ったときに最初に作成
されたインタプリタのことです。 サブインタプリタと違い、メインインタプ
リタにはシグナルハンドリングのような、プロセス全域で唯一な責務がありま
す。 メインインタプリタにはランタイムの初期化中の処理実行という責務も
あり、通常はランタイムの終了処理中に動いているランタイムでもあります。
"PyInterpreterState_Main()" 関数は、メインインタプリタの状態へのポイン
タを返します。

サブインタプリタを切り替えが "PyThreadState_Swap()" 関数でできます。
次の関数を使ってサブインタプリタの作成と削除が行えます:

type PyInterpreterConfig

   Structure containing most parameters to configure a sub-
   interpreter. Its values are used only in
   "Py_NewInterpreterFromConfig()" and never modified by the runtime.

   Added in version 3.12.

   構造体フィールド:

   int use_main_obmalloc

      If this is "0" then the sub-interpreter will use its own
      "object" allocator state. Otherwise it will use (share) the main
      interpreter's.

      If this is "0" then "check_multi_interp_extensions" must be "1"
      (non-zero). If this is "1" then "gil" must not be
      "PyInterpreterConfig_OWN_GIL".

   int allow_fork

      If this is "0" then the runtime will not support forking the
      process in any thread where the sub-interpreter is currently
      active. Otherwise fork is unrestricted.

      Note that the "subprocess" module still works when fork is
      disallowed.

   int allow_exec

      If this is "0" then the runtime will not support replacing the
      current process via exec (e.g. "os.execv()") in any thread where
      the sub-interpreter is currently active. Otherwise exec is
      unrestricted.

      Note that the "subprocess" module still works when exec is
      disallowed.

   int allow_threads

      If this is "0" then the sub-interpreter's "threading" module
      won't create threads. Otherwise threads are allowed.

   int allow_daemon_threads

      If this is "0" then the sub-interpreter's "threading" module
      won't create daemon threads. Otherwise daemon threads are
      allowed (as long as "allow_threads" is non-zero).

   int check_multi_interp_extensions

      If this is "0" then all extension modules may be imported,
      including legacy (single-phase init) modules, in any thread
      where the sub-interpreter is currently active. Otherwise only
      multi-phase init extension modules (see **PEP 489**) may be
      imported. (Also see "Py_mod_multiple_interpreters".)

      This must be "1" (non-zero) if "use_main_obmalloc" is "0".

   int gil

      This determines the operation of the GIL for the sub-
      interpreter. It may be one of the following:

      PyInterpreterConfig_DEFAULT_GIL

         Use the default selection ("PyInterpreterConfig_SHARED_GIL").

      PyInterpreterConfig_SHARED_GIL

         Use (share) the main interpreter's GIL.

      PyInterpreterConfig_OWN_GIL

         Use the sub-interpreter's own GIL.

      If this is "PyInterpreterConfig_OWN_GIL" then
      "PyInterpreterConfig.use_main_obmalloc" must be "0".

PyStatus Py_NewInterpreterFromConfig(PyThreadState **tstate_p, const PyInterpreterConfig *config)

   新しいサブインタプリタ (sub-interpreter) を生成します。サブインタプ
   リタとは、(ほぼ完全に) 個別に分割された Python コードの実行環境です
   。特に、新しいサブインタプリタは、 import されるモジュール全てにつ
   いて個別のバージョンを持ち、これには基盤となるモジュール
   "builtins", "__main__" および "sys" も含まれます。ロード済みのモジ
   ュールからなるテーブル ("sys.modules")  およびモジュール検索パス
   ("sys.path") もサブインタプリタ毎に別個のものになります。新たなサブ
   インタプリタ環境には "sys.argv" 変数がありません。また、サブインタ
   プリタは新たな標準 I/O ストリーム "sys.stdin", "sys.stdout",
   "sys.stderr" を持ちます (とはいえ、これらのストリームは根底にある同
   じファイル記述子を参照しています)。

   The given *config* controls the options with which the interpreter
   is initialized.

   Upon success, *tstate_p* will be set to the first *thread state*
   created in the new sub-interpreter.  This thread state is
   *attached*. Note that no actual thread is created; see the
   discussion of thread states below.  If creation of the new
   interpreter is unsuccessful, *tstate_p* is set to "NULL"; no
   exception is set since the exception state is stored in the
   *attached thread state*, which might not exist.

   Like all other Python/C API functions, an *attached thread state*
   must be present before calling this function, but it might be
   detached upon returning. On success, the returned thread state will
   be *attached*. If the sub-interpreter is created with its own *GIL*
   then the *attached thread state* of the calling interpreter will be
   detached. When the function returns, the new interpreter's *thread
   state* will be *attached* to the current thread and the previous
   interpreter's *attached thread state* will remain detached.

   Added in version 3.12.

   Sub-interpreters are most effective when isolated from each other,
   with certain functionality restricted:

      PyInterpreterConfig config = {
          .use_main_obmalloc = 0,
          .allow_fork = 0,
          .allow_exec = 0,
          .allow_threads = 1,
          .allow_daemon_threads = 0,
          .check_multi_interp_extensions = 1,
          .gil = PyInterpreterConfig_OWN_GIL,
      };
      PyThreadState *tstate = NULL;
      PyStatus status = Py_NewInterpreterFromConfig(&tstate, &config);
      if (PyStatus_Exception(status)) {
          Py_ExitStatusException(status);
      }

   Note that the config is used only briefly and does not get
   modified. During initialization the config's values are converted
   into various "PyInterpreterState" values.  A read-only copy of the
   config may be stored internally on the "PyInterpreterState".

   Extension modules are shared between (sub-)interpreters as follows:

   * For modules using multi-phase initialization, e.g.
     "PyModule_FromDefAndSpec()", a separate module object is created
     and initialized for each interpreter. Only C-level static and
     global variables are shared between these module objects.

   * For modules using single-phase initialization, e.g.
     "PyModule_Create()", the first time a particular extension is
     imported, it is initialized normally, and a (shallow) copy of its
     module's dictionary is squirreled away. When the same extension
     is imported by another (sub-)interpreter, a new module is
     initialized and filled with the contents of this copy; the
     extension's "init" function is not called. Objects in the
     module's dictionary thus end up shared across (sub-)interpreters,
     which might cause unwanted behavior (see Bugs and caveats below).

     Note that this is different from what happens when an extension
     is imported after the interpreter has been completely re-
     initialized by calling "Py_FinalizeEx()" and "Py_Initialize()";
     in that case, the extension's "initmodule" function *is* called
     again. As with multi-phase initialization, this means that only
     C-level static and global variables are shared between these
     modules.

PyThreadState *Py_NewInterpreter(void)
    * 次に属します: Stable ABI.*

   Create a new sub-interpreter.  This is essentially just a wrapper
   around "Py_NewInterpreterFromConfig()" with a config that preserves
   the existing behavior.  The result is an unisolated sub-interpreter
   that shares the main interpreter's GIL, allows fork/exec, allows
   daemon threads, and allows single-phase init modules.

void Py_EndInterpreter(PyThreadState *tstate)
    * 次に属します: Stable ABI.*

   Destroy the (sub-)interpreter represented by the given *thread
   state*. The given thread state must be *attached*. When the call
   returns, there will be no *attached thread state*. All thread
   states associated with this interpreter are destroyed.

   "Py_FinalizeEx()" will destroy all sub-interpreters that haven't
   been explicitly destroyed at that point.


A Per-Interpreter GIL
---------------------

Using "Py_NewInterpreterFromConfig()" you can create a sub-interpreter
that is completely isolated from other interpreters, including having
its own GIL.  The most important benefit of this isolation is that
such an interpreter can execute Python code without being blocked by
other interpreters or blocking any others.  Thus a single Python
process can truly take advantage of multiple CPU cores when running
Python code.  The isolation also encourages a different approach to
concurrency than that of just using threads. (See **PEP 554** and
**PEP 684**.)

Using an isolated interpreter requires vigilance in preserving that
isolation.  That especially means not sharing any objects or mutable
state without guarantees about thread-safety.  Even objects that are
otherwise immutable (e.g. "None", "(1, 5)") can't normally be shared
because of the refcount.  One simple but less-efficient approach
around this is to use a global lock around all use of some state (or
object). Alternately, effectively immutable objects (like integers or
strings) can be made safe in spite of their refcounts by making them
*immortal*. In fact, this has been done for the builtin singletons,
small integers, and a number of other builtin objects.

If you preserve isolation then you will have access to proper multi-
core computing without the complications that come with free-
threading. Failure to preserve isolation will expose you to the full
consequences of free-threading, including races and hard-to-debug
crashes.

Aside from that, one of the main challenges of using multiple isolated
interpreters is how to communicate between them safely (not break
isolation) and efficiently.  The runtime and stdlib do not provide any
standard approach to this yet.  A future stdlib module would help
mitigate the effort of preserving isolation and expose effective tools
for communicating (and sharing) data between interpreters.

Added in version 3.12.


バグと注意事項
--------------

Because sub-interpreters (and the main interpreter) are part of the
same process, the insulation between them isn't perfect --- for
example, using low-level file operations like  "os.close()" they can
(accidentally or maliciously) affect each other's open files.  Because
of the way extensions are shared between (sub-)interpreters, some
extensions may not work properly; this is especially likely when using
single-phase initialization or (static) global variables. It is
possible to insert objects created in one sub-interpreter into a
namespace of another (sub-)interpreter; this should be avoided if
possible.

Special care should be taken to avoid sharing user-defined functions,
methods, instances or classes between sub-interpreters, since import
operations executed by such objects may affect the wrong
(sub-)interpreter's dictionary of loaded modules. It is equally
important to avoid sharing objects from which the above are reachable.

サブインタプリタを "PyGILState_*" API と組み合わせるのが難しいことにも
注意してください。これらのAPIはPythonのスレッド状態とOSレベルスレッド
が1対1で対応していることを前提にしていて、サブインタプリタが存在すると
その前提が崩れるからです。対応する "PyGILState_Ensure()" と
"PyGILState_Release()" の呼び出しのペアの間では、サブインタプリタの切
り替えを行わないことを強く推奨します。さらに、("ctypes" のような)これ
らのAPIを使ってPythonの外で作られたスレッドから Pythonコードを実行して
いる拡張モジュールはサブインタプリタを使うと壊れる可能性があります。


非同期通知
==========

インタプリタのメインスレッドに非同期な通知を行うために提供されている仕
組みです。これらの通知は関数ポインタと void ポインタ引数という形態を取
ります。

int Py_AddPendingCall(int (*func)(void*), void *arg)
    * 次に属します: Stable ABI.*

   インタプリタのメインスレッドから関数が呼び出される予定を組みます。
   成功すると "0" が返り、*func* はメインスレッドの呼び出しキューに詰
   められます。失敗すると、例外をセットせずに "-1" が返ります。

   無事にキューに詰められると、*func* は *いつかは必ず* インタプリタの
   メインスレッドから、*arg* を引数として呼び出されます。この関数は、
   通常の実行中の Python コードに対して非同期に呼び出されますが、次の
   両方の条件に合致したときに呼び出されます:

   * *bytecode* 境界上にいるとき、

   * with the main thread holding an *attached thread state* (*func*
     can therefore use the full C API).

   *func* must return "0" on success, or "-1" on failure with an
   exception set.  *func* won't be interrupted to perform another
   asynchronous notification recursively, but it can still be
   interrupted to switch threads if the *thread state* is detached.

   This function doesn't need an *attached thread state*. However, to
   call this function in a subinterpreter, the caller must have an
   *attached thread state*. Otherwise, the function *func* can be
   scheduled to be called from the wrong interpreter.

   警告:

     これは、非常に特別な場合にのみ役立つ、低レベルな関数です。 *func*
     が可能な限り早く呼び出される保証はありません。メインスレッドがシ
     ステムコールを実行するのに忙しい場合は、 *func* はシステムコール
     が返ってくるまで呼び出されないでしょう。この関数は一般的には、任
     意の C スレッドから Python コードを呼び出すのには **向きません**
     。これの代わりに、 PyGILState API を使用してください。

   Added in version 3.1.

   バージョン 3.9 で変更: If this function is called in a
   subinterpreter, the function *func* is now scheduled to be called
   from the subinterpreter, rather than being called from the main
   interpreter. Each subinterpreter now has its own list of scheduled
   calls.

   バージョン 3.12 で変更: This function now always schedules *func*
   to be run in the main interpreter.

int Py_MakePendingCalls(void)
    * 次に属します: Stable ABI.*

   Execute all pending calls. This is usually executed automatically
   by the interpreter.

   This function returns "0" on success, and returns "-1" with an
   exception set on failure.

   If this is not called in the main thread of the main interpreter,
   this function does nothing and returns "0". The caller must hold an
   *attached thread state*.

   Added in version 3.1.

   バージョン 3.12 で変更: This function only runs pending calls in
   the main interpreter.


プロファイルとトレース (profiling and tracing)
==============================================

Python インタプリタは、プロファイル: 分析 (profile) や実行のトレース:
追跡 (trace) といった機能を組み込むために低水準のサポートを提供してい
ます。このサポートは、プロファイルやデバッグ、適用範囲分析 (coverage
analysis) ツールなどに使われます。

この C インターフェースは、プロファイルやトレース作業時に、Python レベ
ルの呼び出し可能オブジェクトが呼び出されることによるオーバヘッドを避け
、直接 C 関数呼び出しが行えるようにしています。プロファイルやトレース
機能の本質的な特性は変わっていません; インターフェースではトレース関数
をスレッドごとにインストールでき、トレース関数に報告される基本イベント
(basic event) は以前のバージョンにおいて Python レベルのトレース関数で
報告されていたものと同じです。

typedef int (*Py_tracefunc)(PyObject *obj, PyFrameObject *frame, int what, PyObject *arg)

   The type of the trace function registered using
   "PyEval_SetProfile()" and "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 "PyTrace_CALL", "PyTrace_EXCEPTION", "PyTrace_LINE",
   "PyTrace_RETURN", "PyTrace_C_CALL", "PyTrace_C_EXCEPTION",
   "PyTrace_C_RETURN", or "PyTrace_OPCODE", and *arg* depends on the
   value of *what*:

   +---------------------------------+------------------------------------------+
   | *what* の値                     | *arg* の意味                             |
   |=================================|==========================================|
   | "PyTrace_CALL"                  | 常に "Py_None" 。                        |
   +---------------------------------+------------------------------------------+
   | "PyTrace_EXCEPTION"             | "sys.exc_info()" の返す例外情報です。    |
   +---------------------------------+------------------------------------------+
   | "PyTrace_LINE"                  | 常に "Py_None" 。                        |
   +---------------------------------+------------------------------------------+
   | "PyTrace_RETURN"                | 呼び出し側に返される予定の値か、例外によ |
   |                                 | って関数を抜ける場合は "NULL" です。     |
   +---------------------------------+------------------------------------------+
   | "PyTrace_C_CALL"                | 呼び出される関数オブジェクト。           |
   +---------------------------------+------------------------------------------+
   | "PyTrace_C_EXCEPTION"           | 呼び出される関数オブジェクト。           |
   +---------------------------------+------------------------------------------+
   | "PyTrace_C_RETURN"              | 呼び出される関数オブジェクト。           |
   +---------------------------------+------------------------------------------+
   | "PyTrace_OPCODE"                | 常に "Py_None" 。                        |
   +---------------------------------+------------------------------------------+

int PyTrace_CALL

   関数やメソッドが新たに呼び出されたり、ジェネレータが新たなエントリ
   の処理に入ったことを報告する際の、 "Py_tracefunc" の *what* の値で
   す。イテレータやジェネレータ関数の生成は、対応するフレーム内の
   Python バイトコードに制御の委譲 (control transfer) が起こらないため
   報告されないので注意してください。

int PyTrace_EXCEPTION

   例外が送出された際の "Py_tracefunc" の *what* の値です。現在実行さ
   れているフレームで例外がセットされ、何らかのバイトコードが処理され
   た後に、 *what* にこの値がセットされた状態でコールバック関数が呼び
   出されます。この結果、例外の伝播によって Python が呼び出しスタック
   を逆戻りする際に、各フレームから処理が戻るごとにコールバック関数が
   呼び出されます。トレース関数だけがこれらのイベントを受け取ります;
   プロファイラはこの種のイベントを必要としません。

int PyTrace_LINE

   The value passed as the *what* parameter to a "Py_tracefunc"
   function (but not a profiling function) when a line-number event is
   being reported. It may be disabled for a frame by setting
   "f_trace_lines" to *0* on that frame.

int PyTrace_RETURN

   呼び出しが返るときに "Py_tracefunc" 関数に *what* 引数として渡す値
   です。

int PyTrace_C_CALL

   C関数を呼び出す直前に "Py_tracefunc" 関数の *what* 引数として渡す値
   です。

int PyTrace_C_EXCEPTION

   C関数が例外を送出したときに "Py_tracefunc" 関数の *what* 引数として
   渡す値です。

int PyTrace_C_RETURN

   C関数から戻るときに "Py_tracefunc" 関数の *what* 引数として渡す値で
   す。

int PyTrace_OPCODE

   The value for the *what* parameter to "Py_tracefunc" functions (but
   not profiling functions) when a new opcode is about to be executed.
   This event is not emitted by default: it must be explicitly
   requested by setting "f_trace_opcodes" to *1* on the frame.

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 the profile function needs to maintain
   state, using a different value for *obj* for each thread provides a
   convenient and thread-safe place to store it.  The profile function
   is called for all monitored events except "PyTrace_LINE"
   "PyTrace_OPCODE" and "PyTrace_EXCEPTION".

   "sys.setprofile()" 関数も参照してください。

   The caller must have an *attached thread state*.

void PyEval_SetProfileAllThreads(Py_tracefunc func, PyObject *obj)

   Like "PyEval_SetProfile()" but sets the profile function in all
   running threads belonging to the current interpreter instead of the
   setting it only on the current thread.

   The caller must have an *attached thread state*.

   As "PyEval_SetProfile()", this function ignores any exceptions
   raised while setting the profile functions in all threads.

Added in version 3.12.

void PyEval_SetTrace(Py_tracefunc func, PyObject *obj)

   Set the tracing function to *func*.  This is similar to
   "PyEval_SetProfile()", except the tracing function does receive
   line-number events and per-opcode events, but does not receive any
   event related to C function objects being called.  Any trace
   function registered using "PyEval_SetTrace()" will not receive
   "PyTrace_C_CALL", "PyTrace_C_EXCEPTION" or "PyTrace_C_RETURN" as a
   value for the *what* parameter.

   "sys.settrace()" 関数も参照してください。

   The caller must have an *attached thread state*.

void PyEval_SetTraceAllThreads(Py_tracefunc func, PyObject *obj)

   Like "PyEval_SetTrace()" but sets the tracing function in all
   running threads belonging to the current interpreter instead of the
   setting it only on the current thread.

   The caller must have an *attached thread state*.

   As "PyEval_SetTrace()", this function ignores any exceptions raised
   while setting the trace functions in all threads.

Added in version 3.12.


Reference tracing
=================

Added in version 3.13.

typedef int (*PyRefTracer)(PyObject*, int event, void *data)

   The type of the trace function registered using
   "PyRefTracer_SetTracer()". The first parameter is a Python object
   that has been just created (when **event** is set to
   "PyRefTracer_CREATE") or about to be destroyed (when **event** is
   set to "PyRefTracer_DESTROY"). The **data** argument is the opaque
   pointer that was provided when "PyRefTracer_SetTracer()" was
   called.

Added in version 3.13.

int PyRefTracer_CREATE

   The value for the *event* parameter to "PyRefTracer" functions when
   a Python object has been created.

int PyRefTracer_DESTROY

   The value for the *event* parameter to "PyRefTracer" functions when
   a Python object has been destroyed.

int PyRefTracer_SetTracer(PyRefTracer tracer, void *data)

   Register a reference tracer function. The function will be called
   when a new Python has been created or when an object is going to be
   destroyed. If **data** is provided it must be an opaque pointer
   that will be provided when the tracer function is called. Return
   "0" on success. Set an exception and return "-1" on error.

   Not that tracer functions **must not** create Python objects inside
   or otherwise the call will be re-entrant. The tracer also **must
   not** clear any existing exception or set an exception.  A *thread
   state* will be active every time the tracer function is called.

   There must be an *attached thread state* when calling this
   function.

Added in version 3.13.

PyRefTracer PyRefTracer_GetTracer(void **data)

   Get the registered reference tracer function and the value of the
   opaque data pointer that was registered when
   "PyRefTracer_SetTracer()" was called. If no tracer was registered
   this function will return NULL and will set the **data** pointer to
   NULL.

   There must be an *attached thread state* when calling this
   function.

Added in version 3.13.


高度なデバッガサポート (advanced debugger support)
==================================================

以下の関数は高度なデバッグツールでの使用のためだけのものです。

PyInterpreterState *PyInterpreterState_Head()

   インタプリタ状態オブジェクトからなるリストのうち、先頭にあるものを
   返します。

PyInterpreterState *PyInterpreterState_Main()

   メインインタプリタの状態オブジェクトを返します。

PyInterpreterState *PyInterpreterState_Next(PyInterpreterState *interp)

   インタプリタ状態オブジェクトからなるリストのうち、*interp* の次にあ
   るものを返します。

PyThreadState *PyInterpreterState_ThreadHead(PyInterpreterState *interp)

   インタプリタ *interp* に関連付けられているスレッドからなるリストの
   うち、先頭にある "PyThreadState" オブジェクトを返します。

PyThreadState *PyThreadState_Next(PyThreadState *tstate)

   *tstate* と同じ "PyInterpreterState" オブジェクトに属しているスレッ
   ド状態オブジェクトのうち、 *tstate* の次にあるものを返します。


スレッドローカルストレージのサポート
====================================

Python インタプリタは、スレッドローカルストレージ (thread-local
storage, TLS) の低レベルサポートを提供していて、ネイティブの TLS 実装
を内部にラップして Python レベルのスレッドローカルストレージ API
("threading.local") をサポートしています。 CPython の C レベル API は
pthreads や Windows で与えられる TLS と同様です: スレッドキーとスレッ
ドごとに void* 値を関係付ける関数を使います。

A *thread state* does *not* need to be *attached* when calling these
functions; they suppl their own locking.

"Python.h" は TLS API の宣言を include せず、スレッドローカルストレー
ジを使うには "pythread.h" を include する必要があることに注意してくだ
さい。

注釈:

  この API 関数はどれも void* 値の代わりにメモリ管理を行うことはしませ
  ん。 メモリの確保と解放は自前で行う必要があります。 void* 値がたまた
  ま PyObject* だった場合は、 API 関数はそれぞれの値の参照カウントの操
  作は行いません。


スレッド固有ストレージ (Thread Specific Storage, TSS) API
---------------------------------------------------------

TSS API は、 CPython インタプリタに含まれている既存の TLS API を置き換
えるために導入されました。 この API は、スレッドキーの表現に int の代
わりに新しい型 "Py_tss_t" を使います。

Added in version 3.7.

参考: "CPython のスレッドローカルストレージのための新しい C API" (**PEP
    539**)

type Py_tss_t

   このデータ構造体はスレッドキーの状態を表現しています。この構造体の
   定義は、根底の TLS 実装に依存し、キーの初期化状態を表現する内部フィ
   ールドを持ちます。 この構造体には公開 (public) のメンバはありません
   。

   Py_LIMITED_API が定義されていないときは、この型の
   "Py_tss_NEEDS_INIT" による静的メモリ確保ができます。

Py_tss_NEEDS_INIT

   このマクロは "Py_tss_t" 変数の初期化子に展開されます。 このマクロは
   Py_LIMITED_API があるときは定義されません。


動的メモリ確保
~~~~~~~~~~~~~~

動的な "Py_tss_t" のメモリ確保は Py_LIMITED_API でビルドされた拡張モジ
ュールで必要になりますが、その実装がビルド時に不透明なために、この型の
静的なメモリ確保は不可能です。

Py_tss_t *PyThread_tss_alloc()
    * 次に属します: Stable ABI (バージョン 3.7 より).*

   Return a value which is the same state as a value initialized with
   "Py_tss_NEEDS_INIT", or "NULL" in the case of dynamic allocation
   failure.

void PyThread_tss_free(Py_tss_t *key)
    * 次に属します: Stable ABI (バージョン 3.7 より).*

   Free the given *key* allocated by "PyThread_tss_alloc()", after
   first calling "PyThread_tss_delete()" to ensure any associated
   thread locals have been unassigned. This is a no-op if the *key*
   argument is "NULL".

   注釈:

     A freed key becomes a dangling pointer. You should reset the key
     to "NULL".


メソッド
~~~~~~~~

The parameter *key* of these functions must not be "NULL".  Moreover,
the behaviors of "PyThread_tss_set()" and "PyThread_tss_get()" are
undefined if the given "Py_tss_t" has not been initialized by
"PyThread_tss_create()".

int PyThread_tss_is_created(Py_tss_t *key)
    * 次に属します: Stable ABI (バージョン 3.7 より).*

   Return a non-zero value if the given "Py_tss_t" has been
   initialized by "PyThread_tss_create()".

int PyThread_tss_create(Py_tss_t *key)
    * 次に属します: Stable ABI (バージョン 3.7 より).*

   Return a zero value on successful initialization of a TSS key.  The
   behavior is undefined if the value pointed to by the *key* argument
   is not initialized by "Py_tss_NEEDS_INIT".  This function can be
   called repeatedly on the same key -- calling it on an already
   initialized key is a no-op and immediately returns success.

void PyThread_tss_delete(Py_tss_t *key)
    * 次に属します: Stable ABI (バージョン 3.7 より).*

   Destroy a TSS key to forget the values associated with the key
   across all threads, and change the key's initialization state to
   uninitialized.  A destroyed key is able to be initialized again by
   "PyThread_tss_create()". This function can be called repeatedly on
   the same key -- calling it on an already destroyed key is a no-op.

int PyThread_tss_set(Py_tss_t *key, void *value)
    * 次に属します: Stable ABI (バージョン 3.7 より).*

   Return a zero value to indicate successfully associating a void*
   value with a TSS key in the current thread.  Each thread has a
   distinct mapping of the key to a void* value.

void *PyThread_tss_get(Py_tss_t *key)
    * 次に属します: Stable ABI (バージョン 3.7 より).*

   Return the void* value associated with a TSS key in the current
   thread.  This returns "NULL" if no value is associated with the key
   in the current thread.


スレッドローカルストレージ (TLS) API
------------------------------------

バージョン 3.7 で非推奨: This API is superseded by Thread Specific
Storage (TSS) API.

注釈:

  This version of the API does not support platforms where the native
  TLS key is defined in a way that cannot be safely cast to "int".  On
  such platforms, "PyThread_create_key()" will return immediately with
  a failure status, and the other TLS functions will all be no-ops on
  such platforms.

前述の互換性の問題により、このバージョンのAPIは新規のコードで利用すべ
きではありません。

int PyThread_create_key()
    * 次に属します: Stable ABI.*

void PyThread_delete_key(int key)
    * 次に属します: Stable ABI.*

int PyThread_set_key_value(int key, void *value)
    * 次に属します: Stable ABI.*

void *PyThread_get_key_value(int key)
    * 次に属します: Stable ABI.*

void PyThread_delete_key_value(int key)
    * 次に属します: Stable ABI.*

void PyThread_ReInitTLS()
    * 次に属します: Stable ABI.*


同期プリミティブ
================

The C-API provides a basic mutual exclusion lock.

type PyMutex

   A mutual exclusion lock.  The "PyMutex" should be initialized to
   zero to represent the unlocked state.  For example:

      PyMutex mutex = {0};

   Instances of "PyMutex" should not be copied or moved.  Both the
   contents and address of a "PyMutex" are meaningful, and it must
   remain at a fixed, writable location in memory.

   注釈:

     A "PyMutex" currently occupies one byte, but the size should be
     considered unstable.  The size may change in future Python
     releases without a deprecation period.

   Added in version 3.13.

void PyMutex_Lock(PyMutex *m)

   Lock mutex *m*.  If another thread has already locked it, the
   calling thread will block until the mutex is unlocked.  While
   blocked, the thread will temporarily detach the *thread state* if
   one exists.

   Added in version 3.13.

void PyMutex_Unlock(PyMutex *m)

   Unlock mutex *m*. The mutex must be locked --- otherwise, the
   function will issue a fatal error.

   Added in version 3.13.

int PyMutex_IsLocked(PyMutex *m)

   Returns non-zero if the mutex *m* is currently locked, zero
   otherwise.

   注釈:

     This function is intended for use in assertions and debugging
     only and should not be used to make concurrency control
     decisions, as the lock state may change immediately after the
     check.

   Added in version 3.14.


Python Critical Section API
---------------------------

The critical section API provides a deadlock avoidance layer on top of
per-object locks for *free-threaded* CPython.  They are intended to
replace reliance on the *global interpreter lock*, and are no-ops in
versions of Python with the global interpreter lock.

Critical sections are intended to be used for custom types implemented
in C-API extensions. They should generally not be used with built-in
types like "list" and "dict" because their public C-APIs already use
critical sections internally, with the notable exception of
"PyDict_Next()", which requires critical section to be acquired
externally.

Critical sections avoid deadlocks by implicitly suspending active
critical sections, hence, they do not provide exclusive access such as
provided by traditional locks like "PyMutex".  When a critical section
is started, the per-object lock for the object is acquired. If the
code executed inside the critical section calls C-API functions then
it can suspend the critical section thereby releasing the per-object
lock, so other threads can acquire the per-object lock for the same
object.

Variants that accept "PyMutex" pointers rather than Python objects are
also available. Use these variants to start a critical section in a
situation where there is no "PyObject" -- for example, when working
with a C type that does not extend or wrap "PyObject" but still needs
to call into the C API in a manner that might lead to deadlocks.

The functions and structs used by the macros are exposed for cases
where C macros are not available. They should only be used as in the
given macro expansions. Note that the sizes and contents of the
structures may change in future Python versions.

注釈:

  Operations that need to lock two objects at once must use
  "Py_BEGIN_CRITICAL_SECTION2".  You *cannot* use nested critical
  sections to lock more than one object at once, because the inner
  critical section may suspend the outer critical sections.  This API
  does not provide a way to lock more than two objects at once.

使用例:

   static PyObject *
   set_field(MyObject *self, PyObject *value)
   {
      Py_BEGIN_CRITICAL_SECTION(self);
      Py_SETREF(self->field, Py_XNewRef(value));
      Py_END_CRITICAL_SECTION();
      Py_RETURN_NONE;
   }

In the above example, "Py_SETREF" calls "Py_DECREF", which can call
arbitrary code through an object's deallocation function.  The
critical section API avoids potential deadlocks due to reentrancy and
lock ordering by allowing the runtime to temporarily suspend the
critical section if the code triggered by the finalizer blocks and
calls "PyEval_SaveThread()".

Py_BEGIN_CRITICAL_SECTION(op)

   Acquires the per-object lock for the object *op* and begins a
   critical section.

   In the free-threaded build, this macro expands to:

      {
          PyCriticalSection _py_cs;
          PyCriticalSection_Begin(&_py_cs, (PyObject*)(op))

   In the default build, this macro expands to "{".

   Added in version 3.13.

Py_BEGIN_CRITICAL_SECTION_MUTEX(m)

   Locks the mutex *m* and begins a critical section.

   In the free-threaded build, this macro expands to:

      {
           PyCriticalSection _py_cs;
           PyCriticalSection_BeginMutex(&_py_cs, m)

   Note that unlike "Py_BEGIN_CRITICAL_SECTION", there is no cast for
   the argument of the macro - it must be a "PyMutex" pointer.

   On the default build, this macro expands to "{".

   Added in version 3.14.

Py_END_CRITICAL_SECTION()

   Ends the critical section and releases the per-object lock.

   In the free-threaded build, this macro expands to:

          PyCriticalSection_End(&_py_cs);
      }

   In the default build, this macro expands to "}".

   Added in version 3.13.

Py_BEGIN_CRITICAL_SECTION2(a, b)

   Acquires the per-objects locks for the objects *a* and *b* and
   begins a critical section.  The locks are acquired in a consistent
   order (lowest address first) to avoid lock ordering deadlocks.

   In the free-threaded build, this macro expands to:

      {
          PyCriticalSection2 _py_cs2;
          PyCriticalSection2_Begin(&_py_cs2, (PyObject*)(a), (PyObject*)(b))

   In the default build, this macro expands to "{".

   Added in version 3.13.

Py_BEGIN_CRITICAL_SECTION2_MUTEX(m1, m2)

   Locks the mutexes *m1* and *m2* and begins a critical section.

   In the free-threaded build, this macro expands to:

      {
           PyCriticalSection2 _py_cs2;
           PyCriticalSection2_BeginMutex(&_py_cs2, m1, m2)

   Note that unlike "Py_BEGIN_CRITICAL_SECTION2", there is no cast for
   the arguments of the macro - they must be "PyMutex" pointers.

   On the default build, this macro expands to "{".

   Added in version 3.14.

Py_END_CRITICAL_SECTION2()

   Ends the critical section and releases the per-object locks.

   In the free-threaded build, this macro expands to:

          PyCriticalSection2_End(&_py_cs2);
      }

   In the default build, this macro expands to "}".

   Added in version 3.13.


Legacy Locking APIs
-------------------

These APIs are obsolete since Python 3.13 with the introduction of
"PyMutex".

バージョン 3.15 で変更: These APIs are now a simple wrapper around
"PyMutex".

type PyThread_type_lock

   A pointer to a mutual exclusion lock.

type PyLockStatus

   The result of acquiring a lock with a timeout.

   enumerator PY_LOCK_FAILURE

      Failed to acquire the lock.

   enumerator PY_LOCK_ACQUIRED

      The lock was successfully acquired.

   enumerator PY_LOCK_INTR

      The lock was interrupted by a signal.

PyThread_type_lock PyThread_allocate_lock(void)
    * 次に属します: Stable ABI.*

   Allocate a new lock.

   On success, this function returns a lock; on failure, this function
   returns "0" without an exception set.

   The caller does not need to hold an *attached thread state*.

   バージョン 3.15 で変更: This function now always uses "PyMutex". In
   prior versions, this would use a lock provided by the operating
   system.

void PyThread_free_lock(PyThread_type_lock lock)
    * 次に属します: Stable ABI.*

   Destroy *lock*. The lock should not be held by any thread when
   calling this.

   The caller does not need to hold an *attached thread state*.

PyLockStatus PyThread_acquire_lock_timed(PyThread_type_lock lock, long long microseconds, int intr_flag)
    * 次に属します: Stable ABI.*

   Acquire *lock* with a timeout.

   This will wait for *microseconds* microseconds to acquire the lock.
   If the timeout expires, this function returns "PY_LOCK_FAILURE". If
   *microseconds* is "-1", this will wait indefinitely until the lock
   has been released.

   If *intr_flag* is "1", acquiring the lock may be interrupted by a
   signal, in which case this function returns "PY_LOCK_INTR". Upon
   interruption, it's generally expected that the caller makes a call
   to "Py_MakePendingCalls()" to propagate an exception to Python
   code.

   If the lock is successfully acquired, this function returns
   "PY_LOCK_ACQUIRED".

   The caller does not need to hold an *attached thread state*.

int PyThread_acquire_lock(PyThread_type_lock lock, int waitflag)
    * 次に属します: Stable ABI.*

   Acquire *lock*.

   If *waitflag* is "1" and another thread currently holds the lock,
   this function will wait until the lock can be acquired and will
   always return "1".

   If *waitflag* is "0" and another thread holds the lock, this
   function will not wait and instead return "0". If the lock is not
   held by any other thread, then this function will acquire it and
   return "1".

   Unlike "PyThread_acquire_lock_timed()", acquiring the lock cannot
   be interrupted by a signal.

   The caller does not need to hold an *attached thread state*.

int PyThread_release_lock(PyThread_type_lock lock)
    * 次に属します: Stable ABI.*

   Release *lock*. If *lock* is not held, then this function issues a
   fatal error.

   The caller does not need to hold an *attached thread state*.


Operating System Thread APIs
============================

PYTHREAD_INVALID_THREAD_ID

   Sentinel value for an invalid thread ID.

   This is currently equivalent to "(unsigned long)-1".

unsigned long PyThread_start_new_thread(void (*func)(void*), void *arg)
    * 次に属します: Stable ABI.*

   Start function *func* in a new thread with argument *arg*. The
   resulting thread is not intended to be joined.

   *func* must not be "NULL", but *arg* may be "NULL".

   On success, this function returns the identifier of the new thread;
   on failure, this returns "PYTHREAD_INVALID_THREAD_ID".

   The caller does not need to hold an *attached thread state*.

unsigned long PyThread_get_thread_ident(void)
    * 次に属します: Stable ABI.*

   Return the identifier of the current thread, which will never be
   zero.

   This function cannot fail, and the caller does not need to hold an
   *attached thread state*.

   参考: "threading.get_ident()"

PyObject *PyThread_GetInfo(void)
    * 次に属します: Stable ABI (バージョン 3.3 より).*

   Get general information about the current thread in the form of a
   struct sequence object. This information is accessible as
   "sys.thread_info" in Python.

   On success, this returns a new *strong reference* to the thread
   information; on failure, this returns "NULL" with an exception set.

   The caller must hold an *attached thread state*.

PY_HAVE_THREAD_NATIVE_ID

   This macro is defined when the system supports native thread IDs.

unsigned long PyThread_get_thread_native_id(void)
    * 次に属します: Stable ABI on platforms with native thread IDs.*

   Get the native identifier of the current thread as it was assigned
   by the operating system's kernel, which will never be less than
   zero.

   This function is only available when "PY_HAVE_THREAD_NATIVE_ID" is
   defined.

   This function cannot fail, and the caller does not need to hold an
   *attached thread state*.

   参考: "threading.get_native_id()"

void PyThread_exit_thread(void)
    * 次に属します: Stable ABI.*

   Terminate the current thread. This function is generally considered
   unsafe and should be avoided. It is kept solely for backwards
   compatibility.

   This function is only safe to call if all functions in the full
   call stack are written to safely allow it.

   警告:

     If the current system uses POSIX threads (also known as
     "pthreads"), this calls *pthread_exit(3)*, which attempts to
     unwind the stack and call C++ destructors on some libc
     implementations. However, if a "noexcept" function is reached, it
     may terminate the process. Other systems, such as macOS, do
     unwinding.On Windows, this function calls "_endthreadex()", which
     kills the thread without calling C++ destructors.In any case,
     there is a risk of corruption on the thread's stack.

   バージョン 3.14 で非推奨.

void PyThread_init_thread(void)
    * 次に属します: Stable ABI.*

   Initialize "PyThread*" APIs. Python executes this function
   automatically, so there's little need to call it from an extension
   module.

int PyThread_set_stacksize(size_t size)
    * 次に属します: Stable ABI.*

   Set the stack size of the current thread to *size* bytes.

   This function returns "0" on success, "-1" if *size* is invalid, or
   "-2" if the system does not support changing the stack size. This
   function does not set exceptions.

   The caller does not need to hold an *attached thread state*.

size_t PyThread_get_stacksize(void)
    * 次に属します: Stable ABI.*

   Return the stack size of the current thread in bytes, or "0" if the
   system's default stack size is in use.

   The caller does not need to hold an *attached thread state*.
