Inicialização, finalização e threads
************************************

Veja Configuração de inicialização do Python para detalhes sobre como
configurar o interpretador antes da inicialização.


Antes da inicialização do Python
================================

Em uma aplicação que incorpora Python, a função "Py_Initialize()" deve
ser chamada antes de usar qualquer outra função da API Python/C; com
exceção de algumas funções e as variáveis globais de configuração.

As seguintes funções podem ser seguramente chamadas antes da
inicialização do Python.

* Funções que inicializam o interpretador:

  * "Py_Initialize()"

  * "Py_InitializeEx()"

  * "Py_InitializeFromConfig()"

  * "Py_BytesMain()"

  * "Py_Main()"

  * as funções de pré-inicialização de tempo de execução cobertas em
    Configuração de Inicialização do Python

* Funções de configuração:

  * "PyImport_AppendInittab()"

  * "PyImport_ExtendInittab()"

  * "PyInitFrozenExtensions()"

  * "PyMem_SetAllocator()"

  * "PyMem_SetupDebugHooks()"

  * "PyObject_SetArenaAllocator()"

  * "Py_SetProgramName()"

  * "Py_SetPythonHome()"

  * "PySys_ResetWarnOptions()"

  * as funções de configuração cobertas em Configuração de
    Inicialização do Python

* Funções informativas:

  * "Py_IsInitialized()"

  * "PyMem_GetAllocator()"

  * "PyObject_GetArenaAllocator()"

  * "Py_GetBuildInfo()"

  * "Py_GetCompiler()"

  * "Py_GetCopyright()"

  * "Py_GetPlatform()"

  * "Py_GetVersion()"

  * "Py_IsInitialized()"

* Utilitários:

  * "Py_DecodeLocale()"

  * o relatório de status é funções utilitárias cobertas em
    Configuração de Inicialização do Python

* Alocadores de memória:

  * "PyMem_RawMalloc()"

  * "PyMem_RawRealloc()"

  * "PyMem_RawCalloc()"

  * "PyMem_RawFree()"

* Sincronização:

  * "PyMutex_Lock()"

  * "PyMutex_Unlock()"

Nota:

  Apesar de sua aparente semelhança com algumas das funções listadas
  acima, as seguintes funções **não devem ser chamadas** antes que o
  interpretador tenha sido inicializado: "Py_EncodeLocale()",
  "Py_GetPath()", "Py_GetPrefix()", "Py_GetExecPrefix()",
  "Py_GetProgramFullPath()", "Py_GetPythonHome()",
  "Py_GetProgramName()", "PyEval_InitThreads()", e "Py_RunMain()".


Variáveis de configuração global
================================

Python tem variáveis para a configuração global a fim de controlar
diferentes características e opções. Por padrão, estes sinalizadores
são controlados por opções de linha de comando.

Quando um sinalizador é definido por uma opção, o valor do sinalizador
é o número de vezes que a opção foi definida. Por exemplo,``-b``
define "Py_BytesWarningFlag" para 1 e "-bb" define
"Py_BytesWarningFlag" para 2.

int Py_BytesWarningFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.bytes_warning" deve ser usada em seu lugar,
   consulte Configuração de inicialização do Python.

   Emite um aviso ao comparar "bytes" ou "bytearray" com "str" ou
   "bytes" com "int". Emite um erro se for maior ou igual a "2".

   Definida pela opção "-b".

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

int Py_DebugFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.parser_debug" deve ser usada em seu lugar,
   consulte Configuração de inicialização do Python.

   Ativa a saída de depuração do analisador sintático (somente para
   especialistas, dependendo das opções de compilação).

   Definida pela a opção "-d" e a variável de ambiente "PYTHONDEBUG".

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

int Py_DontWriteBytecodeFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.write_bytecode" deve ser usada em seu lugar,
   consulte Configuração de inicialização do Python.

   Se definida como diferente de zero, o Python não tentará escrever
   arquivos ".pyc" na importação de módulos fonte.

   Definida pela opção "-B" e pela variável de ambiente
   "PYTHONDONTWRITEBYTECODE".

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

int Py_FrozenFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.pathconfig_warnings" deve ser usada em seu
   lugar, consulte Configuração de inicialização do Python.

   Suprime mensagens de erro ao calcular o caminho de pesquisa do
   módulo em "Py_GetPath()".

   Sinalizador privado usado pelos programas "_freeze_module" e
   "frozenmain".

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

int Py_HashRandomizationFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração de "PyConfig.hash_seed" e "PyConfig.use_hash_seed"
   deve ser usada em seu lugar, consulte Configuração de inicialização
   do Python.

   Definida como "1" se a variável de ambiente "PYTHONHASHSEED"
   estiver definida como uma string não vazia.

   Se o sinalizador for diferente de zero, lê a variável de ambiente
   "PYTHONHASHSEED" para inicializar a semente de hash secreta.

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

int Py_IgnoreEnvironmentFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.use_environment" deve ser usada em seu
   lugar, consulte Configuração de inicialização do Python.

   Ignora todas as variáveis de ambiente "PYTHON*", por exemplo
   "PYTHONPATH" e "PYTHONHOME", que podem estar definidas.

   Definida pelas opções "-E" e "-I".

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

int Py_InspectFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.inspect" deve ser usada em seu lugar,
   consulte Configuração de inicialização do Python.

   Quando um script é passado como primeiro argumento ou a opção "-c"
   é usada, entre no modo interativo após executar o script ou o
   comando, mesmo quando "sys.stdin" não parece ser um terminal.

   Definida pela opção "-i" e pela variável de ambiente
   "PYTHONINSPECT".

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

int Py_InteractiveFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.interactive" deve ser usada em seu lugar,
   consulte Configuração de inicialização do Python.

   Definida pela opção "-i".

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

int Py_IsolatedFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.isolated" deve ser usada em seu lugar,
   consulte Configuração de inicialização do Python.

   Executa o Python no modo isolado. No modo isolado, "sys.path" não
   contém nem o diretório do script nem o diretório de pacotes de
   sites do usuário.

   Definida pela opção "-I".

   Adicionado na versão 3.4.

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

int Py_LegacyWindowsFSEncodingFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyPreConfig.legacy_windows_fs_encoding" deve ser
   usada em seu lugar, consulte Configuração de inicialização do
   Python.

   Se o sinalizador for diferente de zero, use a codificação "mbcs"
   com o tratador de erros "replace", em vez da codificação UTF-8 com
   o tratador de erros "surrogatepass", para a codificação do sistema
   de arquivos e *tratador de erros e codificação do sistema de
   arquivos*.

   Definida como "1" se a variável de ambiente
   "PYTHONLEGACYWINDOWSFSENCODING" estiver definida como uma string
   não vazia.

   Veja **PEP 529** para mais detalhes.

   Disponibilidade: Windows.

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

int Py_LegacyWindowsStdioFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.legacy_windows_stdio" deve ser usada em seu
   lugar, consulte Configuração de inicialização do Python.

   Se o sinalizador for diferente de zero, usa "io.FileIO" em vez de
   "io._WindowsConsoleIO" para fluxos padrão "sys".

   Definida como "1" se a variável de ambiente
   "PYTHONLEGACYWINDOWSSTDIO" estiver definida como uma string não
   vazia.

   Veja a **PEP 528** para mais detalhes.

   Disponibilidade: Windows.

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

int Py_NoSiteFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.site_import" deve ser usada em seu lugar,
   consulte Configuração de inicialização do Python.

   Desabilita a importação do módulo "site" e as manipulações
   dependentes do site de "sys.path" que isso acarreta. Também
   desabilita essas manipulações se "site" for explicitamente
   importado mais tarde (chame "site.main()" se você quiser que eles
   sejam acionados).

   Definida pela opção "-S".

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

int Py_NoUserSiteDirectory

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.user_site_directory" deve ser usada em seu
   lugar, consulte Configuração de inicialização do Python.

   Não adiciona o "diretório site-packages de usuário" a "sys.path".

   Definida pelas opções "-s" e "-I", e pela variável de ambiente
   "PYTHONNOUSERSITE".

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

int Py_OptimizeFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.optimization_level" deve ser usada em seu
   lugar, consulte Configuração de inicialização do Python.

   Definida pela opção "-O" e pela variável de ambiente
   "PYTHONOPTIMIZE".

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

int Py_QuietFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.quiet" deve ser usada em seu lugar, consulte
   Configuração de inicialização do Python.

   Não exibe as mensagens de direito autoral e de versão nem mesmo no
   modo interativo.

   Definida pela opção "-q".

   Adicionado na versão 3.2.

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

int Py_UnbufferedStdioFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.buffered_stdio" deve ser usada em seu lugar,
   consulte Configuração de inicialização do Python.

   Força os fluxos stdout e stderr a não serem armazenados em buffer.

   Definida pela opção "-u" e pela variável de ambiente
   "PYTHONUNBUFFERED".

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

int Py_VerboseFlag

   Esta API é mantida para compatibilidade com versões anteriores: a
   configuração "PyConfig.verbose" deve ser usada em seu lugar,
   consulte Configuração de inicialização do Python.

   Exibe uma mensagem cada vez que um módulo é inicializado, mostrando
   o local (nome do arquivo ou módulo embutido) de onde ele é
   carregado. Se maior ou igual a "2", exibe uma mensagem para cada
   arquivo que é verificado durante a busca por um módulo. Também
   fornece informações sobre a limpeza do módulo na saída.

   Definida pela a opção "-v" e a variável de ambiente
   "PYTHONVERBOSE".

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


Inicializando e encerrando o interpretador
==========================================

void Py_Initialize()
    * Parte da ABI Estável.*

   Inicializa o interpretador Python. Em uma aplicação que incorpora o
   Python, isto deve ser chamado antes do uso de qualquer outra função
   do Python/C API; veja Antes da Inicialização do Python para algumas
   exceções.

   Isso inicializa a tabela de módulos carregados ("sys.modules") e
   cria os módulos fundamentais "builtins", "__main__" e "sys". Também
   inicializa o caminho de pesquisa de módulos ("sys.path"). Isso não
   define "sys.argv"; use a API da Configuração de inicialização do
   Python para isso. Isso é um no-op quando chamado pela segunda vez
   (sem chamar "Py_FinalizeEx()" primeiro). Não há valor de retorno; é
   um erro fatal se a inicialização falhar.

   Usa "Py_InitializeFromConfig()" para personalizar a Configuração de
   inicialização do Python.

   Nota:

     No Windows, altera o modo do console de "O_TEXT" para "O_BINARY",
     o que também afetará usos não Python do console usando o Runtime
     C.

void Py_InitializeEx(int initsigs)
    * Parte da ABI Estável.*

   Esta função funciona como "Py_Initialize()" se *initsigs* for "1".
   Se *initsigs* for "0", ela pula o registro de inicialização de
   manipuladores de sinal, o que pode ser útil quando o CPython é
   incorporado como parte de uma aplicação maior.

   Usa "Py_InitializeFromConfig()" para personalizar a Configuração de
   inicialização do Python.

PyStatus Py_InitializeFromConfig(const PyConfig *config)

   Inicializa o Python a partir da configuração *config*, conforme
   descrito em Initialization with PyConfig.

   Consulte a seção Configuração de Inicialização do Python para obter
   detalhes sobre como pré-inicializar o interpretador, preencher a
   estrutura de configuração do tempo de execução e consultar a
   estrutura de status retornada.

int Py_IsInitialized()
    * Parte da ABI Estável.*

   Retorna true (diferente de zero) quando o interpretador Python foi
   inicializado, false (zero) se não. Após "Py_FinalizeEx()" ser
   chamado, isso retorna false até que "Py_Initialize()" seja chamado
   novamente.

int Py_IsFinalizing()
    * Parte da ABI Estável desde a versão 3.13.*

   Retorna verdadeiro (diferente de zero) se o interpretador Python
   principal estiver em *desligamento*. Retorna falso (zero) caso
   contrário.

   Adicionado na versão 3.13.

int Py_FinalizeEx()
    * Parte da ABI Estável desde a versão 3.6.*

   Desfaz todas as inicializações feitas por "Py_Initialize()" e o uso
   subsequente de funções da API Python/C, e destrói todos os
   subinterpretadores (veja "Py_NewInterpreter()" abaixo) que foram
   criados e ainda não destruídos desde a última chamada a
   "Py_Initialize()". Esta operação é ineficaz quando chamada pela
   segunda vez (sem chamar "Py_Initialize()" novamente primeiro).

   Como isso é o inverso de "Py_Initialize()", ele deve ser chamado na
   mesma thread com o mesmo interpretador ativo. Isso significa a
   thread principal e o interpretador principal. Isso nunca deve ser
   chamado enquanto "Py_RunMain()" estiver em execução.

   Normalmente, o valor de retorno é "0". Se houver erros durante a
   finalização (limpeza de dados armazenados em buffer), "-1" será
   retornado.

   Observe que o Python fará o máximo possível para liberar toda a
   memória alocada pelo interpretador Python. Portanto, qualquer
   extensão C deve certificar-se de limpar corretamente todos os
   PyObjects alocados anteriormente antes de usá-los em chamadas
   subsequentes para "Py_Initialize()". Caso contrário, isso pode
   introduzir vulnerabilidades e comportamento incorreto.

   Esta função é fornecida por vários motivos. Uma aplicação de
   incorporação pode querer reiniciar o Python sem precisar reiniciar
   a própria aplicação. Uma aplicação que carregou o interpretador
   Python de uma biblioteca carregável dinamicamente (ou DLL) pode
   querer liberar toda a memória alocada pelo Python antes de
   descarregar a DLL. Durante uma busca por vazamentos de memória em
   uma aplicação, um desenvolvedor pode querer liberar toda a memória
   alocada pelo Python antes de sair da aplicação.

   **Bugs e advertências:** A destruição de módulos e objetos em
   módulos é feita em ordem aleatória; isso pode fazer com que
   destrutores (métodos "__del__()") falhem quando dependem de outros
   objetos (até mesmo funções) ou módulos. Módulos de extensão
   carregados dinamicamente pelo Python não são descarregados.
   Pequenas quantidades de memória alocadas pelo interpretador Python
   podem não ser liberadas (se você encontrar um vazamento, por favor,
   reporte-o). Memória presa em referências circulares entre objetos
   não é liberada. Strings internadas serão todas desalocadas
   independentemente de sua contagem de referências. Parte da memória
   alocada por módulos de extensão pode não ser liberada. Algumas
   extensões podem não funcionar corretamente se sua rotina de
   inicialização for chamada mais de uma vez; isso pode acontecer se
   uma aplicação chamar "Py_Initialize()" e "Py_FinalizeEx()" mais de
   uma vez. "Py_FinalizeEx()" não deve ser chamado recursivamente de
   dentro de si mesmo. Portanto, ele não deve ser chamado por nenhum
   código que possa ser executado como parte do processo de
   desligamento do interpretador, como manipuladores "atexit",
   finalizadores de objetos ou qualquer código que possa ser executado
   durante a limpeza dos arquivos de stdout e stderr.

   Levanta um evento de auditoria "cpython._PySys_ClearAuditHooks" sem
   argumentos.

   Adicionado na versão 3.6.

void Py_Finalize()
    * Parte da ABI Estável.*

   Esta é uma versão compatível com retrocompatibilidade de
   "Py_FinalizeEx()" que desconsidera o valor de retorno.

int Py_BytesMain(int argc, char **argv)
    * Parte da ABI Estável desde a versão 3.8.*

   Semelhante a "Py_Main()", mas *argv* é um vetor de strings de
   bytes, permitindo que o aplicativo de chamada delegue a etapa de
   decodificação de texto ao tempo de execução do CPython.

   Adicionado na versão 3.8.

int Py_Main(int argc, wchar_t **argv)
    * Parte da ABI Estável.*

   O programa principal para o interpretador padrão, encapsulando um
   ciclo completo de inicialização/finalização, bem como comportamento
   adicional para implementar a leitura de configurações do ambiente e
   da linha de comando e, em seguida, executar "__main__" de acordo
   com Linha de comando.

   Isso é disponibilizado para programas que desejam oferecer suporte
   à interface de linha de comando completa do CPython, em vez de
   apenas incorporar um tempo de execução do Python em uma aplicação
   maior.

   Os parâmetros *argc* e *argv* são semelhantes aos passados para a
   função "main()" de um programa C, exceto que as entradas *argv* são
   primeiro convertidas para "wchar_t" usando "Py_DecodeLocale()".
   Também é importante observar que as entradas da lista de argumentos
   podem ser modificadas para apontar para strings diferentes daquelas
   passadas (no entanto, o conteúdo das strings apontadas pela lista
   de argumentos não é modificado).

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

   Em termos das APIs de configuração de tempo de execução do CPython
   documentadas na seção de configuração de runtime (e sem levar em
   conta o tratamento de erros), "Py_Main" é aproximadamente
   equivalente a:

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

      Py_RunMain();

   Em uso normal, uma aplicação de incorporação chamará esta função
   *em vez* de chamar "Py_Initialize()", "Py_InitializeEx()" ou
   "Py_InitializeFromConfig()" diretamente, e todas as configurações
   serão aplicadas conforme descrito em outra parte desta
   documentação. Se esta função for chamada *após* uma chamada
   anterior à API de inicialização do runtime, as configurações de
   ambiente e de linha de comando que serão atualizadas dependem da
   versão (pois dependem de quais configurações oferecem suporte
   corretamente à modificação após já terem sido definidas uma vez na
   primeira inicialização do runtime).

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)

   *Esta é uma API Instável. Isso pode se alterado sem aviso em
   lançamentos menores.*

   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*.

   Adicionado na versão 3.13.


Process-wide parameters
=======================

void Py_SetProgramName(const wchar_t *name)
    * Parte da ABI Estável.*

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

   Esta função deve ser chamada antes de "Py_Initialize()" ser chamada
   pela primeira vez, caso seja solicitada. Ela diz ao interpretador o
   valor do argumento "argv[0]" para a função "main()" do programa
   (convertido em caracteres amplos). Isto é utilizado por
   "Py_GetPath()" e algumas outras funções abaixo para encontrar as
   bibliotecas de tempo de execução relativas ao executável do
   interpretador. O valor padrão é "'python'". O argumento deve
   apontar para um caractere string amplo terminado em zero no
   armazenamento estático, cujo conteúdo não mudará durante a execução
   do programa. Nenhum código no interpretador Python mudará o
   conteúdo deste armazenamento.

   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()
    * Parte da ABI Estável.*

   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".

   Alterado na versão 3.10: 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()
    * Parte da ABI Estável.*

   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".

   Alterado na versão 3.10: 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()
    * Parte da ABI Estável.*

   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.

   Background: The exec-prefix differs from the prefix when platform
   dependent files (such as executables and shared libraries) are
   installed in a different directory tree.  In a typical
   installation, platform dependent files may be installed in the
   "/usr/local/plat" subtree while platform independent may be
   installed in "/usr/local".

   Generally speaking, a platform is a combination of hardware and
   software families, e.g.  Sparc machines running the Solaris 2.x
   operating system are considered the same platform, but Intel
   machines running Solaris 2.x are another platform, and Intel
   machines running Linux are yet another platform.  Different major
   revisions of the same operating system generally also form
   different platforms.  Non-Unix operating systems are a different
   story; the installation strategies on those systems are so
   different that the prefix and exec-prefix are meaningless, and set
   to the empty string. Note that compiled Python bytecode files are
   platform independent (but not independent from the Python version
   by which they were compiled!).

   System administrators will know how to configure the **mount** or
   **automount** programs to share "/usr/local" between platforms
   while having "/usr/local/plat" be a different filesystem for each
   platform.

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

   Alterado na versão 3.10: 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()
    * Parte da ABI Estável.*

   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".

   Alterado na versão 3.10: 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()
    * Parte da ABI Estável.*

   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".

   Alterado na versão 3.10: 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()
    * Parte da ABI Estável.*

   Retorna a verão deste interpretador Python. Esta é uma string que
   se parece com

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

   The first word (up to the first space character) is the current
   Python version; the first characters are the major and minor
   version separated by a period.  The returned string points into
   static storage; the caller should not modify its value.  The value
   is available to Python code as "sys.version".

   See also the "Py_Version" constant.

const char *Py_GetPlatform()
    * Parte da ABI Estável.*

   Return the platform identifier for the current platform.  On Unix,
   this is formed from the "official" name of the operating system,
   converted to lower case, followed by the major revision number;
   e.g., for Solaris 2.x, which is also known as SunOS 5.x, the value
   is "'sunos5'".  On macOS, it is "'darwin'".  On Windows, it is
   "'win'".  The returned string points into static storage; the
   caller should not modify its value.  The value is available to
   Python code as "sys.platform".

const char *Py_GetCopyright()
    * Parte da ABI Estável.*

   Retorna a string oficial de direitos autoriais para a versão atual
   do Python, por exemplo

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

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

const char *Py_GetCompiler()
    * Parte da ABI Estável.*

   Retorna uma indicação do compilador usado para construir a atual
   versão do Python, em colchetes, por exemplo:

      "[GCC 2.7.2.2]"

   The returned string points into static storage; the caller should
   not modify its value.  The value is available to Python code as
   part of the variable "sys.version".

const char *Py_GetBuildInfo()
    * Parte da ABI Estável.*

   Retorna informação sobre o número de sequência e a data e hora da
   construção da instância atual do interpretador Python, por exemplo

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

   The returned string points into static storage; the caller should
   not modify its value.  The value is available to Python code as
   part of the variable "sys.version".

void PySys_SetArgvEx(int argc, wchar_t **argv, int updatepath)
    * Parte da ABI Estável.*

   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.

   Set "sys.argv" based on *argc* and *argv*.  These parameters are
   similar to those passed to the program's "main()" function with the
   difference that the first entry should refer to the script file to
   be executed rather than the executable hosting the Python
   interpreter.  If there isn't a script that will be run, the first
   entry in *argv* can be an empty string.  If this function fails to
   initialize "sys.argv", a fatal condition is signalled using
   "Py_FatalError()".

   Se *updatepath* é zero, isto é tudo o que a função faz. Se
   *updatepath* não é zero, a função também modifica "sys.path" de
   acordo com o seguinte algoritmo:

   * If the name of an existing script is passed in "argv[0]", the
     absolute path of the directory where the script is located is
     prepended to "sys.path".

   * Otherwise (that is, if *argc* is "0" or "argv[0]" doesn't point
     to an existing file name), an empty string is prepended to
     "sys.path", which is the same as prepending the current working
     directory (""."").

   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.

   Nota:

     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**.On versions before 3.1.3, you can
     achieve the same effect by manually popping the first "sys.path"
     element after having called "PySys_SetArgv()", for example using:

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

   Adicionado na versão 3.1.3.

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

void PySys_SetArgv(int argc, wchar_t **argv)
    * Parte da ABI Estável.*

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

   This function works like "PySys_SetArgvEx()" with *updatepath* set
   to "1" unless the **python** interpreter was started with the "-I".

   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.

   Alterado na versão 3.4: The *updatepath* value depends on "-I".

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

void Py_SetPythonHome(const wchar_t *home)
    * Parte da ABI Estável.*

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

   Set the default "home" directory, that is, the location of the
   standard Python libraries.  See "PYTHONHOME" for the meaning of the
   argument string.

   The argument should point to a zero-terminated character string in
   static storage whose contents will not change for the duration of
   the program's execution.  No code in the Python interpreter will
   change the contents of this storage.

   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()
    * Parte da ABI Estável.*

   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".

   Alterado na versão 3.10: 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.


Estado de thread e a trava global do interpretador
==================================================

A menos que seja uma construção com *threads livres* do *CPython*, o
interpretador Python não é totalmente seguro para thread. Para
oferecer suporte a programas Python multithread, existe uma trava
global, chamada de *trava global do interpretador* ou *GIL*, que deve
ser mantida pela thread atual antes que ela possa acessar objetos
Python com segurança. Sem a trava, mesmo as operações mais simples
podem causar problemas em um programa multithread: por exemplo, quando
duas threads incrementam simultaneamente a contagem de referências do
mesmo objeto, a contagem de referências pode acabar sendo incrementada
apenas uma vez, no lugar de duas.

Portanto, existe a regra de que somente a thread que adquiriu a *GIL*
pode operar em objetos Python ou chamar funções da API C/Python. Para
emular a simultaneidade de execução, o interpretador tenta alternar
threads regularmente (consulte "sys.setswitchinterval()"). A trava
também é liberada em operações de E/S potencialmente bloqueantes, como
ler ou escrever um arquivo, para que outras threads Python possam ser
executadas enquanto isso.

O interpretador Python mantém algumas informações contábeis
específicas da thread dentro de uma estrutura de dados chamada
"PyThreadState", conhecida como *estado de thread*. Cada thread do SO
possui um ponteiro local da thread para um "PyThreadState"; um estado
de thread referenciado por este ponteiro é considerado *anexado*.

Uma thread só pode ter um *estado de thread anexado* por vez. Um
estado de thread anexado é tipicamente análogo a manter a *GIL*,
exceto em construções com *threads livres*. Em construções com a *GIL*
habilitada, *anexar* um estado de thread vai bloquear até que a *GIL*
possa ser adquirida. No entanto, mesmo em construções com a *GIL*
desabilitada, ainda é necessário ter um estado de thread anexado para
chamar a maior parte da API C.

Em geral, sempre haverá um *estado de thread anexado* ao usar a API C
do Python. Somente em alguns casos específicos (como em um bloco
"Py_BEGIN_ALLOW_THREADS") a thread não terá um estado de thread
anexado. Em caso de dúvida, verifique se
"PyThreadState_GetUnchecked()" retorna "NULL".


Desvinculação do estado de thread do código de extensão
-------------------------------------------------------

A maior parte do código de extensão que manipula o *estado de thread*
tem a seguinte estrutura simples:

   Salve o estado de thread em uma variável local.
   ... Faça alguma operação de E/S com bloqueio...
   Restaure o estado de thread da variável local.

Isso é tão comum que existe um par de macros para simplificá-lo:

   Py_BEGIN_ALLOW_THREADS
   ... Faça alguma operação de E/S com bloqueio...
   Py_END_ALLOW_THREADS

A macro "Py_BEGIN_ALLOW_THREADS" abre um novo bloco e declara uma
variável local oculta; a macro "Py_END_ALLOW_THREADS" fecha o bloco.

O bloco acima se expande para o seguinte código:

   PyThreadState *_save;

   _save = PyEval_SaveThread();
   ... Faça alguma operação de E/S com bloqueio...
   PyEval_RestoreThread(_save);

Veja como essas funções atuam:

O *estado de thread anexado* mantém a *GIL* para todo o interpretador.
Ao desanexar o *estado de thread anexado*, a *GIL* é liberada,
permitindo que outras threads anexem um estado de thread a sua própria
thread, assim obtendo a *GIL* e podendo iniciar a execução. O ponteiro
para o *estado de thread anexado* anterior é armazenado como uma
variável local. Ao chegar a "Py_END_ALLOW_THREADS", o estado de thread
que foi anteriormente *anexado* é passado para
"PyEval_RestoreThread()". Esse função será bloqueada até que outro
libere seu *estado de thread*, permitindo assim que o antigo *estado
de thread* seja re-anexado e a API C possa ser novamente chamada.

Para construções com *threads livres*, a *GIL* normalmente está fora
de questão, mas a separação do *estado de thread* ainda é necessário
para E/S com bloqueio e operações longas. A diferença é que threads
não precisam esperar que a *GIL* seja liberada para anexar seu estado
de thread, permitindo verdadeiro paralelismo de vários núcleos.

Nota:

  Chamar funções de E/S do sistema é o caso de uso mais comum para
  desanexar o *estado de thread*, mas também pode ser útil antes de
  chamar cálculos de longa duração que não precisam de acesso a Python
  objeto, como funções de compressão ou criptografia operando em
  buffers de memória. Por exemplo, os módulos dos padrões "zlib" e
  "hashlib" desanexam o *estado de thread* ao compactar ou fazer
  hashing de dados.


Non-Python created threads
--------------------------

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.

The "PyGILState_Ensure()" and "PyGILState_Release()" functions do all
of the above automatically.  The typical idiom for calling into Python
from a C thread is:

   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();


Cuidados com o uso de 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.


High-level API
--------------

Estes são os tipos e as funções mais comumente usados na escrita de um
código de extensão em C, ou ao incorporar o interpretador Python:

type PyInterpreterState
    * Parte da API Limitada (como uma estrutura opaca).*

   This data structure represents the state shared by a number of
   cooperating threads.  Threads belonging to the same interpreter
   share their module administration and a few other internal items.
   There are no public members in this structure.

   Threads belonging to different interpreters initially share
   nothing, except process state like available memory, open file
   descriptors and such.  The global interpreter lock is also shared
   by all threads, regardless of to which interpreter they belong.

   Alterado na versão 3.12: **PEP 684** introduced the possibility of
   a per-interpreter GIL. See "Py_NewInterpreterFromConfig()".

type PyThreadState
    * Parte da API Limitada (como uma estrutura opaca).*

   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()
    * Parte da ABI Estável.*

   Função descontinuada que não faz nada.

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

   Alterado na versão 3.9: The function now does nothing.

   Alterado na versão 3.7: Esta função agora é chamada por
   "Py_Initialize()", então não há mais necessidade de você chamá-la.

   Alterado na versão 3.2: Esta função não pode mais ser chamada antes
   de "Py_Initialize()".

   Descontinuado desde a versão 3.9.

PyThreadState *PyEval_SaveThread()
    * Parte da ABI Estável.*

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

void PyEval_RestoreThread(PyThreadState *tstate)
    * Parte da ABI Estável.*

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

   Nota:

     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.

   Alterado na versão 3.14: Hangs the current thread, rather than
   terminating it, if called while the interpreter is finalizing.

PyThreadState *PyThreadState_Get()
    * Parte da ABI Estável.*

   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.

   Adicionado na versão 3.13: In Python 3.5 to 3.12, the function was
   private and known as "_PyThreadState_UncheckedGet()".

PyThreadState *PyThreadState_Swap(PyThreadState *tstate)
    * Parte da ABI Estável.*

   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.

   Ver também: "PyEval_ReleaseThread()"

   Nota:

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

The following functions use thread-local storage, and are not
compatible with sub-interpreters:

type PyGILState_STATE
    * Parte da ABI Estável.*

   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()
    * Parte da ABI Estável.*

   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.

   Aviso:

     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.

   Alterado na versão 3.14: Hangs the current thread, rather than
   terminating it, if called while the interpreter is finalizing.

void PyGILState_Release(PyGILState_STATE)
    * Parte da ABI Estável.*

   Release any resources previously acquired.  After this call,
   Python's state will be the same as it was prior to the
   corresponding "PyGILState_Ensure()" call (but generally this state
   will be unknown to the caller, hence the use of the GILState API).

   Every call to "PyGILState_Ensure()" must be matched by a call to
   "PyGILState_Release()" on the same thread.

PyThreadState *PyGILState_GetThisThreadState()
    * Parte da ABI Estável.*

   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.

   Nota:

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

   Ver também: "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.

   Nota:

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

   Adicionado na versão 3.4.

The following macros are normally used without a trailing semicolon;
look for example usage in the Python source distribution.

Py_BEGIN_ALLOW_THREADS
    * Parte da ABI Estável.*

   Esta macro se expande para "{ PyThreadState *_save; _save =
   PyEval_SaveThread();". Observe que ele contém uma chave de
   abertura; ele deve ser combinado com a seguinte macro
   "Py_END_ALLOW_THREADS". Veja acima para uma discussão mais
   aprofundada desta macro.

Py_END_ALLOW_THREADS
    * Parte da ABI Estável.*

   Esta macro se expande para "PyEval_RestoreThread(_save); }".
   Observe que ele contém uma chave de fechamento; ele deve ser
   combinado com uma macro "Py_BEGIN_ALLOW_THREADS" anterior. Veja
   acima para uma discussão mais aprofundada desta macro.

Py_BLOCK_THREADS
    * Parte da ABI Estável.*

   Esta macro se expande para "PyEval_RestoreThread(_save);": é
   equivalente a "Py_END_ALLOW_THREADS" sem a chave de fechamento.

Py_UNBLOCK_THREADS
    * Parte da ABI Estável.*

   Esta macro se expande para "_save = PyEval_SaveThread();": é
   equivalente a "Py_BEGIN_ALLOW_THREADS" sem a chave de abertura e
   declaração de variável.


Low-level API
-------------

All of the following functions must be called after "Py_Initialize()".

Alterado na versão 3.7: "Py_Initialize()" now initializes the *GIL*
and sets an *attached thread state*.

PyInterpreterState *PyInterpreterState_New()
    * Parte da ABI Estável.*

   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.

   Levanta um evento de auditoria "cpython.PyInterpreterState_New" sem
   argumentos.

void PyInterpreterState_Clear(PyInterpreterState *interp)
    * Parte da ABI Estável.*

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

   Levanta um evento de auditoria "cpython.PyInterpreterState_Clear"
   sem argumentos.

void PyInterpreterState_Delete(PyInterpreterState *interp)
    * Parte da ABI Estável.*

   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)
    * Parte da ABI Estável.*

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

void PyThreadState_Clear(PyThreadState *tstate)
    * Parte da ABI Estável.*

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

   Alterado na versão 3.9: This function now calls the
   "PyThreadState.on_delete" callback. Previously, that happened in
   "PyThreadState_Delete()".

   Alterado na versão 3.13: The "PyThreadState.on_delete" callback was
   removed.

void PyThreadState_Delete(PyThreadState *tstate)
    * Parte da ABI Estável.*

   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)
    * Parte da ABI Estável desde a versão 3.10.*

   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*.

   Adicionado na versão 3.9.

uint64_t PyThreadState_GetID(PyThreadState *tstate)
    * Parte da ABI Estável desde a versão 3.10.*

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

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

   Adicionado na versão 3.9.

PyInterpreterState *PyThreadState_GetInterpreter(PyThreadState *tstate)
    * Parte da ABI Estável desde a versão 3.10.*

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

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

   Adicionado na versão 3.9.

void PyThreadState_EnterTracing(PyThreadState *tstate)

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

   Resume them using the "PyThreadState_LeaveTracing()" function.

   Adicionado na versão 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.

   Adicionado na versão 3.11.

PyInterpreterState *PyInterpreterState_Get(void)
    * Parte da ABI Estável desde a versão 3.9.*

   Get the current interpreter.

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

   Adicionado na versão 3.9.

int64_t PyInterpreterState_GetID(PyInterpreterState *interp)
    * Parte da ABI Estável desde a versão 3.7.*

   Return the interpreter's unique ID.  If there was any error in
   doing so then "-1" is returned and an error is set.

   The caller must have an *attached thread state*.

   Adicionado na versão 3.7.

PyObject *PyInterpreterState_GetDict(PyInterpreterState *interp)
    *Retorna valor: Referência emprestada.** Parte da ABI Estável
   desde a versão 3.8.*

   Return a dictionary in which interpreter-specific data may be
   stored. If this function returns "NULL" then no exception has been
   raised and the caller should assume no interpreter-specific dict is
   available.

   This is not a replacement for "PyModule_GetState()", which
   extensions should use to store interpreter-specific state
   information.

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

   Adicionado na versão 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.

   Alterado na versão 3.9: The function now takes a *tstate*
   parameter.

   Alterado na versão 3.11: 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".

   Adicionado na versão 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".

   Adicionado na versão 3.9.

PyObject *PyThreadState_GetDict()
    *Retorna valor: Referência emprestada.** Parte da ABI Estável.*

   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)
    * Parte da ABI Estável.*

   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.

   Alterado na versão 3.7: The type of the *id* parameter changed from
   long to unsigned long.

void PyEval_AcquireThread(PyThreadState *tstate)
    * Parte da ABI Estável.*

   *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*.

   Nota:

     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.

   Alterado na versão 3.8: 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.

   Alterado na versão 3.14: Hangs the current thread, rather than
   terminating it, if called while the interpreter is finalizing.

   "PyEval_RestoreThread()" is a higher-level function which is always
   available (even when threads have not been initialized).

void PyEval_ReleaseThread(PyThreadState *tstate)
    * Parte da ABI Estável.*

   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()" is a higher-level function which is always
   available (even when threads have not been initialized).


Sub-interpreter support
=======================

While in most uses, you will only embed a single Python interpreter,
there are cases where you need to create several independent
interpreters in the same process and perhaps even in the same thread.
Sub-interpreters allow you to do that.

The "main" interpreter is the first one created when the runtime
initializes. It is usually the only Python interpreter in a process.
Unlike sub-interpreters, the main interpreter has unique process-
global responsibilities like signal handling.  It is also responsible
for execution during runtime initialization and is usually the active
interpreter during runtime finalization.  The
"PyInterpreterState_Main()" function returns a pointer to its state.

You can switch between sub-interpreters using the
"PyThreadState_Swap()" function. You can create and destroy them using
the following functions:

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.

   Adicionado na versão 3.12.

   Campos de estrutura:

   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)

   Create a new sub-interpreter.  This is an (almost) totally separate
   environment for the execution of Python code.  In particular, the
   new interpreter has separate, independent versions of all imported
   modules, including the fundamental modules "builtins", "__main__"
   and "sys".  The table of loaded modules ("sys.modules") and the
   module search path ("sys.path") are also separate.  The new
   environment has no "sys.argv" variable.  It has new standard I/O
   stream file objects "sys.stdin", "sys.stdout" and "sys.stderr"
   (however these refer to the same underlying file descriptors).

   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.

   Adicionado na versão 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)
    * Parte da ABI Estável.*

   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)
    * Parte da ABI Estável.*

   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.

Se você preservar o isolamento, terá acesso à computação multi-core
adequada, sem as complicações que acompanham o uso de threads livres.
A falha em preservar o isolamento traz a exposição a todas as
consequências de threads livres, incluindo corridas e travamentos
difíceis de depurar.

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.

Adicionado na versão 3.12.


Bugs and caveats
----------------

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.

Also note that combining this functionality with "PyGILState_*" APIs
is delicate, because these APIs assume a bijection between Python
thread states and OS-level threads, an assumption broken by the
presence of sub-interpreters. It is highly recommended that you don't
switch sub-interpreters between a pair of matching
"PyGILState_Ensure()" and "PyGILState_Release()" calls. Furthermore,
extensions (such as "ctypes") using these APIs to allow calling of
Python code from non-Python created threads will probably be broken
when using sub-interpreters.


Notificações assíncronas
========================

A mechanism is provided to make asynchronous notifications to the main
interpreter thread.  These notifications take the form of a function
pointer and a void pointer argument.

int Py_AddPendingCall(int (*func)(void*), void *arg)
    * Parte da ABI Estável.*

   Schedule a function to be called from the main interpreter thread.
   On success, "0" is returned and *func* is queued for being called
   in the main thread.  On failure, "-1" is returned without setting
   any exception.

   When successfully queued, *func* will be *eventually* called from
   the main interpreter thread with the argument *arg*.  It will be
   called asynchronously with respect to normally running Python code,
   but with both these conditions met:

   * on a *bytecode* boundary;

   * 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.

   Aviso:

     This is a low-level function, only useful for very special cases.
     There is no guarantee that *func* will be called as quick as
     possible.  If the main thread is busy executing a system call,
     *func* won't be called before the system call returns.  This
     function is generally **not** suitable for calling Python code
     from arbitrary C threads.  Instead, use the PyGILState API.

   Adicionado na versão 3.1.

   Alterado na versão 3.9: 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.

   Alterado na versão 3.12: This function now always schedules *func*
   to be run in the main interpreter.


Profiling and Tracing
=====================

The Python interpreter provides some low-level support for attaching
profiling and execution tracing facilities.  These are used for
profiling, debugging, and coverage analysis tools.

This C interface allows the profiling or tracing code to avoid the
overhead of calling through Python-level callable objects, making a
direct C function call instead.  The essential attributes of the
facility have not changed; the interface allows trace functions to be
installed per-thread, and the basic events reported to the trace
function are the same as had been reported to the Python-level trace
functions in previous versions.

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*:

   +---------------------------------+------------------------------------------+
   | Value of *what*                 | Meaning of *arg*                         |
   |=================================|==========================================|
   | "PyTrace_CALL"                  | Always "Py_None".                        |
   +---------------------------------+------------------------------------------+
   | "PyTrace_EXCEPTION"             | Exception information as returned by     |
   |                                 | "sys.exc_info()".                        |
   +---------------------------------+------------------------------------------+
   | "PyTrace_LINE"                  | Always "Py_None".                        |
   +---------------------------------+------------------------------------------+
   | "PyTrace_RETURN"                | Value being returned to the caller, or   |
   |                                 | "NULL" if caused by an exception.        |
   +---------------------------------+------------------------------------------+
   | "PyTrace_C_CALL"                | Function object being called.            |
   +---------------------------------+------------------------------------------+
   | "PyTrace_C_EXCEPTION"           | Function object being called.            |
   +---------------------------------+------------------------------------------+
   | "PyTrace_C_RETURN"              | Function object being called.            |
   +---------------------------------+------------------------------------------+
   | "PyTrace_OPCODE"                | Always "Py_None".                        |
   +---------------------------------+------------------------------------------+

int PyTrace_CALL

   The value of the *what* parameter to a "Py_tracefunc" function when
   a new call to a function or method is being reported, or a new
   entry into a generator. Note that the creation of the iterator for
   a generator function is not reported as there is no control
   transfer to the Python bytecode in the corresponding frame.

int PyTrace_EXCEPTION

   The value of the *what* parameter to a "Py_tracefunc" function when
   an exception has been raised.  The callback function is called with
   this value for *what* when after any bytecode is processed after
   which the exception becomes set within the frame being executed.
   The effect of this is that as exception propagation causes the
   Python stack to unwind, the callback is called upon return to each
   frame as the exception propagates.  Only trace functions receives
   these events; they are not needed by the profiler.

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

   The value for the *what* parameter to "Py_tracefunc" functions when
   a call is about to return.

int PyTrace_C_CALL

   The value for the *what* parameter to "Py_tracefunc" functions when
   a C function is about to be called.

int PyTrace_C_EXCEPTION

   The value for the *what* parameter to "Py_tracefunc" functions when
   a C function has raised an exception.

int PyTrace_C_RETURN

   The value for the *what* parameter to "Py_tracefunc" functions when
   a C function has returned.

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".

   See also the "sys.setprofile()" function.

   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.

Adicionado na versão 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.

   See also the "sys.settrace()" function.

   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.

Adicionado na versão 3.12.


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

Adicionado na versão 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.

Adicionado na versão 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.

Adicionado na versão 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.

Adicionado na versão 3.13.


Advanced Debugger Support
=========================

These functions are only intended to be used by advanced debugging
tools.

PyInterpreterState *PyInterpreterState_Head()

   Return the interpreter state object at the head of the list of all
   such objects.

PyInterpreterState *PyInterpreterState_Main()

   Return the main interpreter state object.

PyInterpreterState *PyInterpreterState_Next(PyInterpreterState *interp)

   Return the next interpreter state object after *interp* from the
   list of all such objects.

PyThreadState *PyInterpreterState_ThreadHead(PyInterpreterState *interp)

   Return the pointer to the first "PyThreadState" object in the list
   of threads associated with the interpreter *interp*.

PyThreadState *PyThreadState_Next(PyThreadState *tstate)

   Return the next thread state object after *tstate* from the list of
   all such objects belonging to the same "PyInterpreterState" object.


Thread Local Storage Support
============================

The Python interpreter provides low-level support for thread-local
storage (TLS) which wraps the underlying native TLS implementation to
support the Python-level thread local storage API ("threading.local").
The CPython C level APIs are similar to those offered by pthreads and
Windows: use a thread key and functions to associate a void* value per
thread.

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

Note that "Python.h" does not include the declaration of the TLS APIs,
you need to include "pythread.h" to use thread-local storage.

Nota:

  None of these API functions handle memory management on behalf of
  the void* values.  You need to allocate and deallocate them
  yourself. If the void* values happen to be PyObject*, these
  functions don't do refcount operations on them either.


Thread Specific Storage (TSS) API
---------------------------------

TSS API is introduced to supersede the use of the existing TLS API
within the CPython interpreter.  This API uses a new type "Py_tss_t"
instead of int to represent thread keys.

Adicionado na versão 3.7.

Ver também:

  "A New C-API for Thread-Local Storage in CPython" (**PEP 539**)

type Py_tss_t

   This data structure represents the state of a thread key, the
   definition of which may depend on the underlying TLS
   implementation, and it has an internal field representing the key's
   initialization state.  There are no public members in this
   structure.

   Quando Py_LIMITED_API não é definido, a alocação estática deste
   tipo por "Py_tss_NEEDS_INIT" é permitida.

Py_tss_NEEDS_INIT

   This macro expands to the initializer for "Py_tss_t" variables.
   Note that this macro won't be defined with Py_LIMITED_API.


Alocação dinâmica
~~~~~~~~~~~~~~~~~

Dynamic allocation of the "Py_tss_t", required in extension modules
built with Py_LIMITED_API, where static allocation of this type is not
possible due to its implementation being opaque at build time.

Py_tss_t *PyThread_tss_alloc()
    * Parte da ABI Estável desde a versão 3.7.*

   Retorna um valor que é o mesmo estado de um valor inicializado com
   "Py_tss_NEEDS_INIT", ou "NULL" no caso de falha de alocação
   dinâmica.

void PyThread_tss_free(Py_tss_t *key)
    * Parte da ABI Estável desde a versão 3.7.*

   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".

   Nota:

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


Métodos
~~~~~~~

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)
    * Parte da ABI Estável desde a versão 3.7.*

   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)
    * Parte da ABI Estável desde a versão 3.7.*

   Retorna um valor zero na inicialização bem-sucedida de uma chave
   TSS. O comportamento é indefinido se o valor apontado pelo
   argumento *key* não for inicializado por "Py_tss_NEEDS_INIT". Essa
   função pode ser chamada repetidamente na mesma tecla -- chamá-la em
   uma tecla já inicializada não funciona e retorna imediatamente com
   sucesso.

void PyThread_tss_delete(Py_tss_t *key)
    * Parte da ABI Estável desde a versão 3.7.*

   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)
    * Parte da ABI Estável desde a versão 3.7.*

   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)
    * Parte da ABI Estável desde a versão 3.7.*

   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.


Thread Local Storage (TLS) API
------------------------------

Descontinuado desde a versão 3.7: This API is superseded by Thread
Specific Storage (TSS) API.

Nota:

  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.

Due to the compatibility problem noted above, this version of the API
should not be used in new code.

int PyThread_create_key()
    * Parte da ABI Estável.*

void PyThread_delete_key(int key)
    * Parte da ABI Estável.*

int PyThread_set_key_value(int key, void *value)
    * Parte da ABI Estável.*

void *PyThread_get_key_value(int key)
    * Parte da ABI Estável.*

void PyThread_delete_key_value(int key)
    * Parte da ABI Estável.*

void PyThread_ReInitTLS()
    * Parte da ABI Estável.*


Synchronization Primitives
==========================

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.

   Nota:

     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.

   Adicionado na versão 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.

   Adicionado na versão 3.13.

void PyMutex_Unlock(PyMutex *m)

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

   Adicionado na versão 3.13.

int PyMutex_IsLocked(PyMutex *m)

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

   Nota:

     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.

   Adicionado na versão 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.

Nota:

  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.

Exemplo de uso:

   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 "{".

   Adicionado na versão 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 "{".

   Adicionado na versão 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 "}".

   Adicionado na versão 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 "{".

   Adicionado na versão 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 "{".

   Adicionado na versão 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 "}".

   Adicionado na versão 3.13.
