manage GIL acquisition when doing things inside of pdal::plang

.github/workflows/build.yml

@@ -24,19 +24,21 @@ jobs:
       fail-fast: true
       matrix:
         os: ['ubuntu-latest', 'macos-latest', 'windows-latest']
-        python-version: ['3.8', '3.9', '3.10']
+        python-version: ['3.9', '3.10', '3.11', '3.12']
 
     steps:
     - name: Check out
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
 
     - name: Setup micromamba
-      uses: mamba-org/provision-with-micromamba@main
+      uses: conda-incubator/setup-miniconda@v3
       with:
+        miniforge-variant: Mambaforge
+        miniforge-version: latest
+        use-mamba: true
+        auto-update-conda: true
         environment-file: .github/environment.yml
-        extra-specs: |
-          python=${{ matrix.python-version }}
-          sel(linux): compilers
+
 
     - name: Install
       shell: bash -l {0}
@@ -67,11 +69,14 @@ jobs:
         python-version: ['3.9']
 
     steps:
-    - uses: actions/checkout@v2
-    - uses: conda-incubator/setup-miniconda@v2
+    - uses: actions/checkout@v4
+    - name: Setup micromamba
+      uses: conda-incubator/setup-miniconda@v3
       with:
-        channels: conda-forge
-        python-version: ${{ matrix.python-version }}
+        miniforge-variant: Mambaforge
+        miniforge-version: latest
+        use-mamba: true
+        auto-update-conda: true
         mamba-version: "*"
 
     - name: Dependencies
@@ -84,7 +89,7 @@ jobs:
         python setup.py sdist
         ls dist
 
-    - uses: pypa/gh-action-pypi-publish@master
+    - uses: pypa/gh-action-pypi-publish@release/v1
       name: Publish package
       if: github.event_name == 'release' && github.event.action == 'published'
       with:

pdal/filters/PythonFilter.cpp

@@ -148,6 +148,7 @@ PointViewSet PythonFilter::run(PointViewPtr view)
     log()->get(LogLevel::Debug5) << "filters.python " << *m_script <<
         " processing " << (int)view->size() << " points." << std::endl;
 
+    plang::gil_scoped_acquire acquire;
     m_pythonMethod->execute(view, getMetadata());
 
     PointViewSet viewSet;

pdal/io/NumpyReader.cpp

@@ -198,6 +198,7 @@ PyArrayObject* load_npy_script(std::string const& source,
 void NumpyReader::initialize()
 {
     plang::Environment::get();
+    plang::gil_scoped_acquire acquire;
     m_numPoints = 0;
     m_chunkCount = 0;
     m_ndims = 0;
@@ -424,6 +425,7 @@ void NumpyReader::addDimensions(PointLayoutPtr layout)
 {
     using namespace Dimension;
 
+    plang::gil_scoped_acquire acquire;
     wakeUpNumpyArray();
     createFields(layout);
 
@@ -485,6 +487,7 @@ void NumpyReader::addDimensions(PointLayoutPtr layout)
 
 void NumpyReader::ready(PointTableRef table)
 {
+    plang::gil_scoped_acquire acquire;
     plang::Environment::get()->set_stdout(log()->getLogStream());
 
     // Set our iterators
@@ -528,6 +531,8 @@ bool NumpyReader::nextPoint()
     // just advance by the stride.
     if (--m_chunkCount == 0)
     {
+        // Go grab the gil before we touch Python stuff again
+        plang::gil_scoped_acquire acquire;
         // If we can't fetch the next ite
         if (!m_iternext(m_iter))
             return false;
@@ -653,6 +658,7 @@ bool NumpyReader::processOne(PointRef& point)
 
 point_count_t NumpyReader::read(PointViewPtr view, point_count_t numToRead)
 {
+    plang::gil_scoped_acquire acquire;
     PointId idx = view->size();
     point_count_t numRead(0);
 
@@ -670,8 +676,8 @@ point_count_t NumpyReader::read(PointViewPtr view, point_count_t numToRead)
 
 void NumpyReader::done(PointTableRef)
 {
+    plang::gil_scoped_acquire acquire;
     // Dereference everything we're using
-
     if (m_iter)
         NpyIter_Deallocate(m_iter);
 

pdal/plang/Environment.cpp

@@ -114,7 +114,19 @@ EnvironmentPtr Environment::get()
 
     auto init = []()
     {
+        PyGILState_STATE gstate;
+
+        // If the interpreter is already initialized, we need to
+        // grab the GIL and hold it before we go do any Python
+        // stuff
+        bool alreadyInitialized(Py_IsInitialized());
+        if (alreadyInitialized)
+            gstate = PyGILState_Ensure();
+
         g_environment = new Environment();
+
+        if (alreadyInitialized)
+            PyGILState_Release(gstate);
     };
     std::call_once(flag, init);
     return g_environment;
@@ -150,8 +162,10 @@ Environment::Environment()
             throw pdal_error("unable to add redirector module!");
     }
 
+
     initNumpy();
     PyImport_ImportModule("redirector");
+
 }
 
 Environment::~Environment()

pdal/plang/Environment.hpp

@@ -47,6 +47,7 @@
 
 #include "Redirector.hpp"
 #include "Script.hpp"
+#include "gil.hpp"
 
 namespace pdal
 {

pdal/plang/Invocation.cpp

@@ -122,6 +122,7 @@ Invocation::Invocation(const Script& script, MetadataNode m,
     m_script(script), m_inputMetadata(m), m_pdalargs(pdalArgs)
 {
     Environment::get();
+    gil_scoped_acquire acquire;
     compile();
 }
 
@@ -357,6 +358,7 @@ PyObject* getPyJSON(std::string const& s)
 // Returns a new reference to a dictionary of numpy arrays/names.
 PyObject *Invocation::prepareData(PointViewPtr& view)
 {
+    gil_scoped_acquire acquire;
     PointLayoutPtr layout(view->m_pointTable.layout());
     Dimension::IdList const& dims = layout->dims();
 

pdal/plang/Redirector.cpp

@@ -7,6 +7,7 @@
 // Blog article: http://mateusz.loskot.net/?p=2819
 
 #include "Redirector.hpp"
+#include "gil.hpp"
 
 #pragma warning(disable: 4127)  // conditional expression is constant
 #pragma warning(disable: 4068)  // gcc pragma warnings
@@ -30,6 +31,7 @@ struct Stdout
 
 static PyObject* Stdout_write(PyObject* self, PyObject* args)
 {
+    gil_scoped_acquire acquire;
     std::size_t written(0);
     Stdout* selfimpl = reinterpret_cast<Stdout*>(self);
     if (selfimpl->write)
@@ -48,6 +50,7 @@ static PyObject* Stdout_write(PyObject* self, PyObject* args)
 
 static PyObject* Stdout_flush(PyObject* self, PyObject* /*args*/)
 {
+    gil_scoped_acquire acquire;
     Stdout *selfimpl = reinterpret_cast<Stdout *>(self);
     if (selfimpl->flush)
     {
@@ -151,9 +154,12 @@ static struct PyModuleDef redirectordef = {
 
 PyObject* Redirector::init()
 {
+    gil_scoped_acquire acquire;
     StdoutType.tp_new = PyType_GenericNew;
     if (PyType_Ready(&StdoutType) < 0)
+    {
         return NULL;
+    }
     PyObject* m = PyModule_Create(&redirectordef);
     if (m)
     {
@@ -171,6 +177,8 @@ PyObject* Redirector::init()
 
 void Redirector::set_stdout(std::ostream* ostr)
 {
+    gil_scoped_acquire acquire;
+
     stdout_write_type writeFunc = [ostr](std::string msg) { *ostr << msg; };
     stdout_flush_type flushFunc = [ostr]{ ostr->flush(); };
 
@@ -180,6 +188,8 @@ void Redirector::set_stdout(std::ostream* ostr)
 
 void Redirector::set_stdout(stdout_write_type write, stdout_flush_type flush)
 {
+    gil_scoped_acquire acquire;
+
     if (!m_stdout)
     {
         m_stdout_saved =
@@ -196,11 +206,15 @@ void Redirector::set_stdout(stdout_write_type write, stdout_flush_type flush)
 
 void Redirector::reset_stdout()
 {
+    PyGILState_STATE gstate;
+    gstate = PyGILState_Ensure();
+
     if (m_stdout_saved)
         PySys_SetObject(const_cast<char*>("stdout"), m_stdout_saved);
 
     Py_XDECREF(m_stdout);
     m_stdout = 0;
+    PyGILState_Release(gstate);
 }
 
 } //namespace plang

pdal/plang/gil.hpp

@@ -0,0 +1,52 @@
+/*
+    pybind11/gil.h: RAII helpers for managing the GIL
+
+    Copyright (c) 2016 Wenzel Jakob <[email protected]>
+
+    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 <Python.h>
+
+
+namespace pdal
+{
+namespace plang
+{
+
+
+class gil_scoped_acquire {
+    PyGILState_STATE state;
+
+public:
+    gil_scoped_acquire() : state{PyGILState_Ensure()} {}
+    gil_scoped_acquire(const gil_scoped_acquire &) = delete;
+    gil_scoped_acquire &operator=(const gil_scoped_acquire &) = delete;
+    ~gil_scoped_acquire() { PyGILState_Release(state); }
+    void disarm() {}
+};
+
+class gil_scoped_release {
+    PyThreadState *state;
+
+public:
+    // PRECONDITION: The GIL must be held when this constructor is called.
+    gil_scoped_release() {
+        assert(PyGILState_Check());
+        state = PyEval_SaveThread();
+    }
+    gil_scoped_release(const gil_scoped_release &) = delete;
+    gil_scoped_release &operator=(const gil_scoped_release &) = delete;
+    ~gil_scoped_release() { PyEval_RestoreThread(state); }
+    void disarm() {}
+};
+
+
+
+
+} // plang
+
+}  // pdal

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name="pdal-plugins",
-    version="1.2.1",
+    version="1.3.0",
     description="Point cloud data processing Python plugins",
     license="BSD",
     keywords="point cloud spatial",