Tomas Ukkonen
2024-07-07 19:24:04 UTC
Hello
Is this python c api bug? The following C++ code (g++) deadlocks on Ubuntu Linux.
/* * This code deadlocks on python3-dev 3.12.3 (ubuntu 24.04 lts)
*
* g++ python_thread_test.cpp `python3-config --cflags --libs --embed`
* ./a.out
*
* uname:
* Linux softice 6.8.0-36-generic SMP PREEMPT_DYNAMIC x86_64 GNU/Linux
*/
#include <Python.h>
#include <thread>
#include <vector>
#include <iostream>
void perform_long_operation() {
// Simulate a long-running task
std::this_thread::sleep_for(std::chrono::seconds(5));
}
void thread_function() {
// Ensure this thread has the GIL
PyGILState_STATE gstate = PyGILState_Ensure();
// Execute some Python code
PyRun_SimpleString("print('Hello from std::thread!')");
// Release the GIL for long operation
Py_BEGIN_ALLOW_THREADS
perform_long_operation();
Py_END_ALLOW_THREADS
// Re-acquire the GIL and execute more Python code
gstate = PyGILState_Ensure();
PyRun_SimpleString("print('Thread operation completed!')");
// Release the GIL
PyGILState_Release(gstate);
}
int main() {
// Initialize the Python Interpreter
Py_Initialize();
// Create a vector of threads
std::vector<std::thread> threads;
// Launch threads
for (int i = 0; i < 5; ++i) {
threads.push_back(std::thread(thread_function));
}
// Join threads
for (auto& t : threads) {
t.join();
}
// Finalize the Python Interpreter
Py_Finalize();
return 0;
}
Tomas Ukkonen
Is this python c api bug? The following C++ code (g++) deadlocks on Ubuntu Linux.
/* * This code deadlocks on python3-dev 3.12.3 (ubuntu 24.04 lts)
*
* g++ python_thread_test.cpp `python3-config --cflags --libs --embed`
* ./a.out
*
* uname:
* Linux softice 6.8.0-36-generic SMP PREEMPT_DYNAMIC x86_64 GNU/Linux
*/
#include <Python.h>
#include <thread>
#include <vector>
#include <iostream>
void perform_long_operation() {
// Simulate a long-running task
std::this_thread::sleep_for(std::chrono::seconds(5));
}
void thread_function() {
// Ensure this thread has the GIL
PyGILState_STATE gstate = PyGILState_Ensure();
// Execute some Python code
PyRun_SimpleString("print('Hello from std::thread!')");
// Release the GIL for long operation
Py_BEGIN_ALLOW_THREADS
perform_long_operation();
Py_END_ALLOW_THREADS
// Re-acquire the GIL and execute more Python code
gstate = PyGILState_Ensure();
PyRun_SimpleString("print('Thread operation completed!')");
// Release the GIL
PyGILState_Release(gstate);
}
int main() {
// Initialize the Python Interpreter
Py_Initialize();
// Create a vector of threads
std::vector<std::thread> threads;
// Launch threads
for (int i = 0; i < 5; ++i) {
threads.push_back(std::thread(thread_function));
}
// Join threads
for (auto& t : threads) {
t.join();
}
// Finalize the Python Interpreter
Py_Finalize();
return 0;
}
Tomas Ukkonen