Extract gil management functions to separate header (#2845)
diff --git a/CMakeLists.txt b/CMakeLists.txt index 7aac2e8..152763e 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt
@@ -117,6 +117,7 @@ include/pybind11/eigen.h include/pybind11/embed.h include/pybind11/eval.h + include/pybind11/gil.h include/pybind11/iostream.h include/pybind11/functional.h include/pybind11/numpy.h
diff --git a/include/pybind11/gil.h b/include/pybind11/gil.h new file mode 100644 index 0000000..32f1a89 --- /dev/null +++ b/include/pybind11/gil.h
@@ -0,0 +1,193 @@ +/* + pybind11/gil.h: RAII helpers for managing the GIL + + Copyright (c) 2016 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 "detail/common.h" +#include "detail/internals.h" + +PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE) + + +PYBIND11_NAMESPACE_BEGIN(detail) + +// forward declarations +PyThreadState *get_thread_state_unchecked(); + +PYBIND11_NAMESPACE_END(detail) + + +#if defined(WITH_THREAD) && !defined(PYPY_VERSION) + +/* The functions below essentially reproduce the PyGILState_* API using a RAII + * pattern, but there are a few important differences: + * + * 1. When acquiring the GIL from an non-main thread during the finalization + * phase, the GILState API blindly terminates the calling thread, which + * is often not what is wanted. This API does not do this. + * + * 2. The gil_scoped_release function can optionally cut the relationship + * of a PyThreadState and its associated thread, which allows moving it to + * another thread (this is a fairly rare/advanced use case). + * + * 3. The reference count of an acquired thread state can be controlled. This + * can be handy to prevent cases where callbacks issued from an external + * thread would otherwise constantly construct and destroy thread state data + * structures. + * + * See the Python bindings of NanoGUI (http://github.com/wjakob/nanogui) for an + * example which uses features 2 and 3 to migrate the Python thread of + * execution to another thread (to run the event loop on the original thread, + * in this case). + */ + +class gil_scoped_acquire { +public: + PYBIND11_NOINLINE gil_scoped_acquire() { + auto const &internals = detail::get_internals(); + tstate = (PyThreadState *) PYBIND11_TLS_GET_VALUE(internals.tstate); + + if (!tstate) { + /* Check if the GIL was acquired using the PyGILState_* API instead (e.g. if + calling from a Python thread). Since we use a different key, this ensures + we don't create a new thread state and deadlock in PyEval_AcquireThread + below. Note we don't save this state with internals.tstate, since we don't + create it we would fail to clear it (its reference count should be > 0). */ + tstate = PyGILState_GetThisThreadState(); + } + + if (!tstate) { + tstate = PyThreadState_New(internals.istate); + #if !defined(NDEBUG) + if (!tstate) + pybind11_fail("scoped_acquire: could not create thread state!"); + #endif + tstate->gilstate_counter = 0; + PYBIND11_TLS_REPLACE_VALUE(internals.tstate, tstate); + } else { + release = detail::get_thread_state_unchecked() != tstate; + } + + if (release) { + PyEval_AcquireThread(tstate); + } + + inc_ref(); + } + + void inc_ref() { + ++tstate->gilstate_counter; + } + + PYBIND11_NOINLINE void dec_ref() { + --tstate->gilstate_counter; + #if !defined(NDEBUG) + if (detail::get_thread_state_unchecked() != tstate) + pybind11_fail("scoped_acquire::dec_ref(): thread state must be current!"); + if (tstate->gilstate_counter < 0) + pybind11_fail("scoped_acquire::dec_ref(): reference count underflow!"); + #endif + if (tstate->gilstate_counter == 0) { + #if !defined(NDEBUG) + if (!release) + pybind11_fail("scoped_acquire::dec_ref(): internal error!"); + #endif + PyThreadState_Clear(tstate); + if (active) + PyThreadState_DeleteCurrent(); + PYBIND11_TLS_DELETE_VALUE(detail::get_internals().tstate); + release = false; + } + } + + /// This method will disable the PyThreadState_DeleteCurrent call and the + /// GIL won't be acquired. This method should be used if the interpreter + /// could be shutting down when this is called, as thread deletion is not + /// allowed during shutdown. Check _Py_IsFinalizing() on Python 3.7+, and + /// protect subsequent code. + PYBIND11_NOINLINE void disarm() { + active = false; + } + + PYBIND11_NOINLINE ~gil_scoped_acquire() { + dec_ref(); + if (release) + PyEval_SaveThread(); + } +private: + PyThreadState *tstate = nullptr; + bool release = true; + bool active = true; +}; + +class gil_scoped_release { +public: + explicit gil_scoped_release(bool disassoc = false) : disassoc(disassoc) { + // `get_internals()` must be called here unconditionally in order to initialize + // `internals.tstate` for subsequent `gil_scoped_acquire` calls. Otherwise, an + // initialization race could occur as multiple threads try `gil_scoped_acquire`. + const auto &internals = detail::get_internals(); + tstate = PyEval_SaveThread(); + if (disassoc) { + auto key = internals.tstate; + PYBIND11_TLS_DELETE_VALUE(key); + } + } + + /// This method will disable the PyThreadState_DeleteCurrent call and the + /// GIL won't be acquired. This method should be used if the interpreter + /// could be shutting down when this is called, as thread deletion is not + /// allowed during shutdown. Check _Py_IsFinalizing() on Python 3.7+, and + /// protect subsequent code. + PYBIND11_NOINLINE void disarm() { + active = false; + } + + ~gil_scoped_release() { + if (!tstate) + return; + // `PyEval_RestoreThread()` should not be called if runtime is finalizing + if (active) + PyEval_RestoreThread(tstate); + if (disassoc) { + auto key = detail::get_internals().tstate; + PYBIND11_TLS_REPLACE_VALUE(key, tstate); + } + } +private: + PyThreadState *tstate; + bool disassoc; + bool active = true; +}; +#elif defined(PYPY_VERSION) +class gil_scoped_acquire { + PyGILState_STATE state; +public: + gil_scoped_acquire() { state = PyGILState_Ensure(); } + ~gil_scoped_acquire() { PyGILState_Release(state); } + void disarm() {} +}; + +class gil_scoped_release { + PyThreadState *state; +public: + gil_scoped_release() { state = PyEval_SaveThread(); } + ~gil_scoped_release() { PyEval_RestoreThread(state); } + void disarm() {} +}; +#else +class gil_scoped_acquire { + void disarm() {} +}; +class gil_scoped_release { + void disarm() {} +}; +#endif + +PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h index 08c51c6..648300e 100644 --- a/include/pybind11/pybind11.h +++ b/include/pybind11/pybind11.h
@@ -43,6 +43,7 @@ #endif #include "attr.h" +#include "gil.h" #include "options.h" #include "detail/class.h" #include "detail/init.h" @@ -2091,173 +2092,6 @@ detail::print(c.args(), c.kwargs()); } -#if defined(WITH_THREAD) && !defined(PYPY_VERSION) - -/* The functions below essentially reproduce the PyGILState_* API using a RAII - * pattern, but there are a few important differences: - * - * 1. When acquiring the GIL from an non-main thread during the finalization - * phase, the GILState API blindly terminates the calling thread, which - * is often not what is wanted. This API does not do this. - * - * 2. The gil_scoped_release function can optionally cut the relationship - * of a PyThreadState and its associated thread, which allows moving it to - * another thread (this is a fairly rare/advanced use case). - * - * 3. The reference count of an acquired thread state can be controlled. This - * can be handy to prevent cases where callbacks issued from an external - * thread would otherwise constantly construct and destroy thread state data - * structures. - * - * See the Python bindings of NanoGUI (http://github.com/wjakob/nanogui) for an - * example which uses features 2 and 3 to migrate the Python thread of - * execution to another thread (to run the event loop on the original thread, - * in this case). - */ - -class gil_scoped_acquire { -public: - PYBIND11_NOINLINE gil_scoped_acquire() { - auto const &internals = detail::get_internals(); - tstate = (PyThreadState *) PYBIND11_TLS_GET_VALUE(internals.tstate); - - if (!tstate) { - /* Check if the GIL was acquired using the PyGILState_* API instead (e.g. if - calling from a Python thread). Since we use a different key, this ensures - we don't create a new thread state and deadlock in PyEval_AcquireThread - below. Note we don't save this state with internals.tstate, since we don't - create it we would fail to clear it (its reference count should be > 0). */ - tstate = PyGILState_GetThisThreadState(); - } - - if (!tstate) { - tstate = PyThreadState_New(internals.istate); - #if !defined(NDEBUG) - if (!tstate) - pybind11_fail("scoped_acquire: could not create thread state!"); - #endif - tstate->gilstate_counter = 0; - PYBIND11_TLS_REPLACE_VALUE(internals.tstate, tstate); - } else { - release = detail::get_thread_state_unchecked() != tstate; - } - - if (release) { - PyEval_AcquireThread(tstate); - } - - inc_ref(); - } - - void inc_ref() { - ++tstate->gilstate_counter; - } - - PYBIND11_NOINLINE void dec_ref() { - --tstate->gilstate_counter; - #if !defined(NDEBUG) - if (detail::get_thread_state_unchecked() != tstate) - pybind11_fail("scoped_acquire::dec_ref(): thread state must be current!"); - if (tstate->gilstate_counter < 0) - pybind11_fail("scoped_acquire::dec_ref(): reference count underflow!"); - #endif - if (tstate->gilstate_counter == 0) { - #if !defined(NDEBUG) - if (!release) - pybind11_fail("scoped_acquire::dec_ref(): internal error!"); - #endif - PyThreadState_Clear(tstate); - if (active) - PyThreadState_DeleteCurrent(); - PYBIND11_TLS_DELETE_VALUE(detail::get_internals().tstate); - release = false; - } - } - - /// This method will disable the PyThreadState_DeleteCurrent call and the - /// GIL won't be acquired. This method should be used if the interpreter - /// could be shutting down when this is called, as thread deletion is not - /// allowed during shutdown. Check _Py_IsFinalizing() on Python 3.7+, and - /// protect subsequent code. - PYBIND11_NOINLINE void disarm() { - active = false; - } - - PYBIND11_NOINLINE ~gil_scoped_acquire() { - dec_ref(); - if (release) - PyEval_SaveThread(); - } -private: - PyThreadState *tstate = nullptr; - bool release = true; - bool active = true; -}; - -class gil_scoped_release { -public: - explicit gil_scoped_release(bool disassoc = false) : disassoc(disassoc) { - // `get_internals()` must be called here unconditionally in order to initialize - // `internals.tstate` for subsequent `gil_scoped_acquire` calls. Otherwise, an - // initialization race could occur as multiple threads try `gil_scoped_acquire`. - const auto &internals = detail::get_internals(); - tstate = PyEval_SaveThread(); - if (disassoc) { - auto key = internals.tstate; - PYBIND11_TLS_DELETE_VALUE(key); - } - } - - /// This method will disable the PyThreadState_DeleteCurrent call and the - /// GIL won't be acquired. This method should be used if the interpreter - /// could be shutting down when this is called, as thread deletion is not - /// allowed during shutdown. Check _Py_IsFinalizing() on Python 3.7+, and - /// protect subsequent code. - PYBIND11_NOINLINE void disarm() { - active = false; - } - - ~gil_scoped_release() { - if (!tstate) - return; - // `PyEval_RestoreThread()` should not be called if runtime is finalizing - if (active) - PyEval_RestoreThread(tstate); - if (disassoc) { - auto key = detail::get_internals().tstate; - PYBIND11_TLS_REPLACE_VALUE(key, tstate); - } - } -private: - PyThreadState *tstate; - bool disassoc; - bool active = true; -}; -#elif defined(PYPY_VERSION) -class gil_scoped_acquire { - PyGILState_STATE state; -public: - gil_scoped_acquire() { state = PyGILState_Ensure(); } - ~gil_scoped_acquire() { PyGILState_Release(state); } - void disarm() {} -}; - -class gil_scoped_release { - PyThreadState *state; -public: - gil_scoped_release() { state = PyEval_SaveThread(); } - ~gil_scoped_release() { PyEval_RestoreThread(state); } - void disarm() {} -}; -#else -class gil_scoped_acquire { - void disarm() {} -}; -class gil_scoped_release { - void disarm() {} -}; -#endif - error_already_set::~error_already_set() { if (m_type) { gil_scoped_acquire gil;
diff --git a/tests/extra_python_package/test_files.py b/tests/extra_python_package/test_files.py index 991dd94..064a3e1 100644 --- a/tests/extra_python_package/test_files.py +++ b/tests/extra_python_package/test_files.py
@@ -25,6 +25,7 @@ "include/pybind11/embed.h", "include/pybind11/eval.h", "include/pybind11/functional.h", + "include/pybind11/gil.h", "include/pybind11/iostream.h", "include/pybind11/numpy.h", "include/pybind11/operators.h",