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Diffstat (limited to 'ext/pybind11/include/pybind11/detail/internals.h')
-rw-r--r-- | ext/pybind11/include/pybind11/detail/internals.h | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/ext/pybind11/include/pybind11/detail/internals.h b/ext/pybind11/include/pybind11/detail/internals.h new file mode 100644 index 000000000..213cbaeb2 --- /dev/null +++ b/ext/pybind11/include/pybind11/detail/internals.h @@ -0,0 +1,247 @@ +/* + pybind11/detail/internals.h: Internal data structure and related functions + + Copyright (c) 2017 Wenzel Jakob <wenzel.jakob@epfl.ch> + + All rights reserved. Use of this source code is governed by a + BSD-style license that can be found in the LICENSE file. +*/ + +#pragma once + +#include "../pytypes.h" + +NAMESPACE_BEGIN(PYBIND11_NAMESPACE) +NAMESPACE_BEGIN(detail) +// Forward declarations +inline PyTypeObject *make_static_property_type(); +inline PyTypeObject *make_default_metaclass(); +inline PyObject *make_object_base_type(PyTypeObject *metaclass); + +// Python loads modules by default with dlopen with the RTLD_LOCAL flag; under libc++ and possibly +// other STLs, this means `typeid(A)` from one module won't equal `typeid(A)` from another module +// even when `A` is the same, non-hidden-visibility type (e.g. from a common include). Under +// libstdc++, this doesn't happen: equality and the type_index hash are based on the type name, +// which works. If not under a known-good stl, provide our own name-based hash and equality +// functions that use the type name. +#if defined(__GLIBCXX__) +inline bool same_type(const std::type_info &lhs, const std::type_info &rhs) { return lhs == rhs; } +using type_hash = std::hash<std::type_index>; +using type_equal_to = std::equal_to<std::type_index>; +#else +inline bool same_type(const std::type_info &lhs, const std::type_info &rhs) { + return lhs.name() == rhs.name() || std::strcmp(lhs.name(), rhs.name()) == 0; +} + +struct type_hash { + size_t operator()(const std::type_index &t) const { + size_t hash = 5381; + const char *ptr = t.name(); + while (auto c = static_cast<unsigned char>(*ptr++)) + hash = (hash * 33) ^ c; + return hash; + } +}; + +struct type_equal_to { + bool operator()(const std::type_index &lhs, const std::type_index &rhs) const { + return lhs.name() == rhs.name() || std::strcmp(lhs.name(), rhs.name()) == 0; + } +}; +#endif + +template <typename value_type> +using type_map = std::unordered_map<std::type_index, value_type, type_hash, type_equal_to>; + +struct overload_hash { + inline size_t operator()(const std::pair<const PyObject *, const char *>& v) const { + size_t value = std::hash<const void *>()(v.first); + value ^= std::hash<const void *>()(v.second) + 0x9e3779b9 + (value<<6) + (value>>2); + return value; + } +}; + +/// Internal data structure used to track registered instances and types. +/// Whenever binary incompatible changes are made to this structure, +/// `PYBIND11_INTERNALS_VERSION` must be incremented. +struct internals { + type_map<type_info *> registered_types_cpp; // std::type_index -> pybind11's type information + std::unordered_map<PyTypeObject *, std::vector<type_info *>> registered_types_py; // PyTypeObject* -> base type_info(s) + std::unordered_multimap<const void *, instance*> registered_instances; // void * -> instance* + std::unordered_set<std::pair<const PyObject *, const char *>, overload_hash> inactive_overload_cache; + type_map<std::vector<bool (*)(PyObject *, void *&)>> direct_conversions; + std::unordered_map<const PyObject *, std::vector<PyObject *>> patients; + std::forward_list<void (*) (std::exception_ptr)> registered_exception_translators; + std::unordered_map<std::string, void *> shared_data; // Custom data to be shared across extensions + std::vector<PyObject *> loader_patient_stack; // Used by `loader_life_support` + std::forward_list<std::string> static_strings; // Stores the std::strings backing detail::c_str() + PyTypeObject *static_property_type; + PyTypeObject *default_metaclass; + PyObject *instance_base; +#if defined(WITH_THREAD) + decltype(PyThread_create_key()) tstate = 0; // Usually an int but a long on Cygwin64 with Python 3.x + PyInterpreterState *istate = nullptr; +#endif +}; + +/// Additional type information which does not fit into the PyTypeObject. +/// Changes to this struct also require bumping `PYBIND11_INTERNALS_VERSION`. +struct type_info { + PyTypeObject *type; + const std::type_info *cpptype; + size_t type_size, holder_size_in_ptrs; + void *(*operator_new)(size_t); + void (*init_instance)(instance *, const void *); + void (*dealloc)(value_and_holder &v_h); + std::vector<PyObject *(*)(PyObject *, PyTypeObject *)> implicit_conversions; + std::vector<std::pair<const std::type_info *, void *(*)(void *)>> implicit_casts; + std::vector<bool (*)(PyObject *, void *&)> *direct_conversions; + buffer_info *(*get_buffer)(PyObject *, void *) = nullptr; + void *get_buffer_data = nullptr; + void *(*module_local_load)(PyObject *, const type_info *) = nullptr; + /* A simple type never occurs as a (direct or indirect) parent + * of a class that makes use of multiple inheritance */ + bool simple_type : 1; + /* True if there is no multiple inheritance in this type's inheritance tree */ + bool simple_ancestors : 1; + /* for base vs derived holder_type checks */ + bool default_holder : 1; + /* true if this is a type registered with py::module_local */ + bool module_local : 1; +}; + +/// Tracks the `internals` and `type_info` ABI version independent of the main library version +#define PYBIND11_INTERNALS_VERSION 1 + +#if defined(WITH_THREAD) +# define PYBIND11_INTERNALS_KIND "" +#else +# define PYBIND11_INTERNALS_KIND "_without_thread" +#endif + +#define PYBIND11_INTERNALS_ID "__pybind11_internals_v" \ + PYBIND11_TOSTRING(PYBIND11_INTERNALS_VERSION) PYBIND11_INTERNALS_KIND "__" + +#define PYBIND11_MODULE_LOCAL_ID "__pybind11_module_local_v" \ + PYBIND11_TOSTRING(PYBIND11_INTERNALS_VERSION) PYBIND11_INTERNALS_KIND "__" + +/// Each module locally stores a pointer to the `internals` data. The data +/// itself is shared among modules with the same `PYBIND11_INTERNALS_ID`. +inline internals *&get_internals_ptr() { + static internals *internals_ptr = nullptr; + return internals_ptr; +} + +/// Return a reference to the current `internals` data +PYBIND11_NOINLINE inline internals &get_internals() { + auto *&internals_ptr = get_internals_ptr(); + if (internals_ptr) + return *internals_ptr; + + constexpr auto *id = PYBIND11_INTERNALS_ID; + auto builtins = handle(PyEval_GetBuiltins()); + if (builtins.contains(id) && isinstance<capsule>(builtins[id])) { + internals_ptr = *static_cast<internals **>(capsule(builtins[id])); + + // We loaded builtins through python's builtins, which means that our `error_already_set` + // and `builtin_exception` may be different local classes than the ones set up in the + // initial exception translator, below, so add another for our local exception classes. + // + // libstdc++ doesn't require this (types there are identified only by name) +#if !defined(__GLIBCXX__) + internals_ptr->registered_exception_translators.push_front( + [](std::exception_ptr p) -> void { + try { + if (p) std::rethrow_exception(p); + } catch (error_already_set &e) { e.restore(); return; + } catch (const builtin_exception &e) { e.set_error(); return; + } + } + ); +#endif + } else { + internals_ptr = new internals(); +#if defined(WITH_THREAD) + PyEval_InitThreads(); + PyThreadState *tstate = PyThreadState_Get(); + internals_ptr->tstate = PyThread_create_key(); + PyThread_set_key_value(internals_ptr->tstate, tstate); + internals_ptr->istate = tstate->interp; +#endif + builtins[id] = capsule(&internals_ptr); + internals_ptr->registered_exception_translators.push_front( + [](std::exception_ptr p) -> void { + try { + if (p) std::rethrow_exception(p); + } catch (error_already_set &e) { e.restore(); return; + } catch (const builtin_exception &e) { e.set_error(); return; + } catch (const std::bad_alloc &e) { PyErr_SetString(PyExc_MemoryError, e.what()); return; + } catch (const std::domain_error &e) { PyErr_SetString(PyExc_ValueError, e.what()); return; + } catch (const std::invalid_argument &e) { PyErr_SetString(PyExc_ValueError, e.what()); return; + } catch (const std::length_error &e) { PyErr_SetString(PyExc_ValueError, e.what()); return; + } catch (const std::out_of_range &e) { PyErr_SetString(PyExc_IndexError, e.what()); return; + } catch (const std::range_error &e) { PyErr_SetString(PyExc_ValueError, e.what()); return; + } catch (const std::exception &e) { PyErr_SetString(PyExc_RuntimeError, e.what()); return; + } catch (...) { + PyErr_SetString(PyExc_RuntimeError, "Caught an unknown exception!"); + return; + } + } + ); + internals_ptr->static_property_type = make_static_property_type(); + internals_ptr->default_metaclass = make_default_metaclass(); + internals_ptr->instance_base = make_object_base_type(internals_ptr->default_metaclass); + } + return *internals_ptr; +} + +/// Works like `internals.registered_types_cpp`, but for module-local registered types: +inline type_map<type_info *> ®istered_local_types_cpp() { + static type_map<type_info *> locals{}; + return locals; +} + +/// Constructs a std::string with the given arguments, stores it in `internals`, and returns its +/// `c_str()`. Such strings objects have a long storage duration -- the internal strings are only +/// cleared when the program exits or after interpreter shutdown (when embedding), and so are +/// suitable for c-style strings needed by Python internals (such as PyTypeObject's tp_name). +template <typename... Args> +const char *c_str(Args &&...args) { + auto &strings = get_internals().static_strings; + strings.emplace_front(std::forward<Args>(args)...); + return strings.front().c_str(); +} + +NAMESPACE_END(detail) + +/// Returns a named pointer that is shared among all extension modules (using the same +/// pybind11 version) running in the current interpreter. Names starting with underscores +/// are reserved for internal usage. Returns `nullptr` if no matching entry was found. +inline PYBIND11_NOINLINE void *get_shared_data(const std::string &name) { + auto &internals = detail::get_internals(); + auto it = internals.shared_data.find(name); + return it != internals.shared_data.end() ? it->second : nullptr; +} + +/// Set the shared data that can be later recovered by `get_shared_data()`. +inline PYBIND11_NOINLINE void *set_shared_data(const std::string &name, void *data) { + detail::get_internals().shared_data[name] = data; + return data; +} + +/// Returns a typed reference to a shared data entry (by using `get_shared_data()`) if +/// such entry exists. Otherwise, a new object of default-constructible type `T` is +/// added to the shared data under the given name and a reference to it is returned. +template<typename T> +T &get_or_create_shared_data(const std::string &name) { + auto &internals = detail::get_internals(); + auto it = internals.shared_data.find(name); + T *ptr = (T *) (it != internals.shared_data.end() ? it->second : nullptr); + if (!ptr) { + ptr = new T(); + internals.shared_data[name] = ptr; + } + return *ptr; +} + +NAMESPACE_END(PYBIND11_NAMESPACE) |