cpython/Modules/_uuidmodule.c
Brett Simmers c2627d6eea
gh-116322: Add Py_mod_gil module slot (#116882)
This PR adds the ability to enable the GIL if it was disabled at
interpreter startup, and modifies the multi-phase module initialization
path to enable the GIL when loading a module, unless that module's spec
includes a slot indicating it can run safely without the GIL.

PEP 703 called the constant for the slot `Py_mod_gil_not_used`; I went
with `Py_MOD_GIL_NOT_USED` for consistency with gh-104148.

A warning will be issued up to once per interpreter for the first
GIL-using module that is loaded. If `-v` is given, a shorter message
will be printed to stderr every time a GIL-using module is loaded
(including the first one that issues a warning).
2024-05-03 11:30:55 -04:00

131 lines
3.3 KiB
C

/*
* Python UUID module that wraps libuuid or Windows rpcrt4.dll.
* DCE compatible Universally Unique Identifier library.
*/
// Need limited C API version 3.13 for Py_mod_gil
#include "pyconfig.h" // Py_GIL_DISABLED
#ifndef Py_GIL_DISABLED
# define Py_LIMITED_API 0x030d0000
#endif
#include "Python.h"
#if defined(HAVE_UUID_H)
// AIX, FreeBSD, libuuid with pkgconf
#include <uuid.h>
#elif defined(HAVE_UUID_UUID_H)
// libuuid without pkgconf
#include <uuid/uuid.h>
#endif
#ifdef MS_WINDOWS
#include <rpc.h>
#endif
#ifndef MS_WINDOWS
static PyObject *
py_uuid_generate_time_safe(PyObject *Py_UNUSED(context),
PyObject *Py_UNUSED(ignored))
{
uuid_t uuid;
#ifdef HAVE_UUID_GENERATE_TIME_SAFE
int res;
res = uuid_generate_time_safe(uuid);
return Py_BuildValue("y#i", (const char *) uuid, sizeof(uuid), res);
#elif defined(HAVE_UUID_CREATE)
uint32_t status;
uuid_create(&uuid, &status);
# if defined(HAVE_UUID_ENC_BE)
unsigned char buf[sizeof(uuid)];
uuid_enc_be(buf, &uuid);
return Py_BuildValue("y#i", buf, sizeof(uuid), (int) status);
# else
return Py_BuildValue("y#i", (const char *) &uuid, sizeof(uuid), (int) status);
# endif /* HAVE_UUID_CREATE */
#else /* HAVE_UUID_GENERATE_TIME_SAFE */
uuid_generate_time(uuid);
return Py_BuildValue("y#O", (const char *) uuid, sizeof(uuid), Py_None);
#endif /* HAVE_UUID_GENERATE_TIME_SAFE */
}
#else /* MS_WINDOWS */
static PyObject *
py_UuidCreate(PyObject *Py_UNUSED(context),
PyObject *Py_UNUSED(ignored))
{
UUID uuid;
RPC_STATUS res;
Py_BEGIN_ALLOW_THREADS
res = UuidCreateSequential(&uuid);
Py_END_ALLOW_THREADS
switch (res) {
case RPC_S_OK:
case RPC_S_UUID_LOCAL_ONLY:
case RPC_S_UUID_NO_ADDRESS:
/*
All success codes, but the latter two indicate that the UUID is random
rather than based on the MAC address. If the OS can't figure this out,
neither can we, so we'll take it anyway.
*/
return Py_BuildValue("y#", (const char *)&uuid, sizeof(uuid));
}
PyErr_SetFromWindowsErr(res);
return NULL;
}
#endif /* MS_WINDOWS */
static int
uuid_exec(PyObject *module) {
assert(sizeof(uuid_t) == 16);
#if defined(MS_WINDOWS)
int has_uuid_generate_time_safe = 0;
#elif defined(HAVE_UUID_GENERATE_TIME_SAFE)
int has_uuid_generate_time_safe = 1;
#else
int has_uuid_generate_time_safe = 0;
#endif
if (PyModule_AddIntConstant(module, "has_uuid_generate_time_safe",
has_uuid_generate_time_safe) < 0) {
return -1;
}
return 0;
}
static PyMethodDef uuid_methods[] = {
#if defined(HAVE_UUID_UUID_H) || defined(HAVE_UUID_H)
{"generate_time_safe", py_uuid_generate_time_safe, METH_NOARGS, NULL},
#endif
#if defined(MS_WINDOWS)
{"UuidCreate", py_UuidCreate, METH_NOARGS, NULL},
#endif
{NULL, NULL, 0, NULL} /* sentinel */
};
static PyModuleDef_Slot uuid_slots[] = {
{Py_mod_exec, uuid_exec},
{Py_mod_multiple_interpreters, Py_MOD_PER_INTERPRETER_GIL_SUPPORTED},
{Py_mod_gil, Py_MOD_GIL_NOT_USED},
{0, NULL}
};
static struct PyModuleDef uuidmodule = {
PyModuleDef_HEAD_INIT,
.m_name = "_uuid",
.m_size = 0,
.m_methods = uuid_methods,
.m_slots = uuid_slots,
};
PyMODINIT_FUNC
PyInit__uuid(void)
{
return PyModuleDef_Init(&uuidmodule);
}