- cpython/Include/object.h
- cpython/Include/cpython/object.h
- cpython/Python/ceval.c
- cpython/Include/ceval.h
- cpython/Python/pythonrun.c
This is the layout of PyObject. It's the basic part of every other Python object
Every object in Python can be cast to PyObject, e.g., list, tuple, etc.
PyObject_HEAD_EXTRA is the head of the double linked list, it's used for keeping track in Garbage Collection
ob_refcnt stores reference count of the current object, it's also used in Garbage Collection
ob_type is a pointer to its type object. For example, type("abc") ===> str, "abc" is the PyObject, and ob_type in the PyObject will point to str
Whenever you execute a Python program from a .py file, the compile phase will translate the human-readable source code to a form called Python bytecode
The pyc file will be generated if necessary, and the interpreter phase will start the main loop, executing the bytecode in the pyc file line by line
The compiled pyc file will not boost the runtime of the program. Instead, the load time of the program will be faster because it doesn't need to generate the pyc file again
According to PEP 3147, after Python 3.3, pyc files will only be generated through the import mechanism, and pyc files will exist under the __pycache__ directory
The main loop of the interpreter is defined in cpython/Python/ceval.c
main_loop:
for (;;) {
// jump to fast_next_opcode if necessary
// check for signal hndler/async io handler
// drop gil if needed
fast_next_opcode:
switch (opcode) {
/* ... */
}
}We can draw the procedure
This is the definition of PyInterpreterState
This is the definition of PyThreadState
If we have two threads currently running
