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cpython/Modules/_testinternalcapi/clinic/test_lock.c.h

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gh-108724: Add PyMutex and _PyParkingLot APIs (gh-109344) PyMutex is a one byte lock with fast, inlineable lock and unlock functions for the common uncontended case. The design is based on WebKit's WTF::Lock. PyMutex is built using the _PyParkingLot APIs, which provides a cross-platform futex-like API (based on WebKit's WTF::ParkingLot). This internal API will be used for building other synchronization primitives used to implement PEP 703, such as one-time initialization and events. This also includes tests and a mini benchmark in Tools/lockbench/lockbench.py to compare with the existing PyThread_type_lock. Uncontended acquisition + release: * Linux (x86-64): PyMutex: 11 ns, PyThread_type_lock: 44 ns * macOS (arm64): PyMutex: 13 ns, PyThread_type_lock: 18 ns * Windows (x86-64): PyMutex: 13 ns, PyThread_type_lock: 38 ns PR Overview: The primary purpose of this PR is to implement PyMutex, but there are a number of support pieces (described below). * PyMutex: A 1-byte lock that doesn't require memory allocation to initialize and is generally faster than the existing PyThread_type_lock. The API is internal only for now. * _PyParking_Lot: A futex-like API based on the API of the same name in WebKit. Used to implement PyMutex. * _PyRawMutex: A word sized lock used to implement _PyParking_Lot. * PyEvent: A one time event. This was used a bunch in the "nogil" fork and is useful for testing the PyMutex implementation, so I've included it as part of the PR. * pycore_llist.h: Defines common operations on doubly-linked list. Not strictly necessary (could do the list operations manually), but they come up frequently in the "nogil" fork. ( Similar to https://man.freebsd.org/cgi/man.cgi?queue) --------- Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
2023-09-19 17:54:29 +02:00
/*[clinic input]
preserve
[clinic start generated code]*/
#include "pycore_abstract.h" // _PyNumber_Index()
#include "pycore_modsupport.h" // _PyArg_CheckPositional()
gh-108724: Add PyMutex and _PyParkingLot APIs (gh-109344) PyMutex is a one byte lock with fast, inlineable lock and unlock functions for the common uncontended case. The design is based on WebKit's WTF::Lock. PyMutex is built using the _PyParkingLot APIs, which provides a cross-platform futex-like API (based on WebKit's WTF::ParkingLot). This internal API will be used for building other synchronization primitives used to implement PEP 703, such as one-time initialization and events. This also includes tests and a mini benchmark in Tools/lockbench/lockbench.py to compare with the existing PyThread_type_lock. Uncontended acquisition + release: * Linux (x86-64): PyMutex: 11 ns, PyThread_type_lock: 44 ns * macOS (arm64): PyMutex: 13 ns, PyThread_type_lock: 18 ns * Windows (x86-64): PyMutex: 13 ns, PyThread_type_lock: 38 ns PR Overview: The primary purpose of this PR is to implement PyMutex, but there are a number of support pieces (described below). * PyMutex: A 1-byte lock that doesn't require memory allocation to initialize and is generally faster than the existing PyThread_type_lock. The API is internal only for now. * _PyParking_Lot: A futex-like API based on the API of the same name in WebKit. Used to implement PyMutex. * _PyRawMutex: A word sized lock used to implement _PyParking_Lot. * PyEvent: A one time event. This was used a bunch in the "nogil" fork and is useful for testing the PyMutex implementation, so I've included it as part of the PR. * pycore_llist.h: Defines common operations on doubly-linked list. Not strictly necessary (could do the list operations manually), but they come up frequently in the "nogil" fork. ( Similar to https://man.freebsd.org/cgi/man.cgi?queue) --------- Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
2023-09-19 17:54:29 +02:00
PyDoc_STRVAR(_testinternalcapi_benchmark_locks__doc__,
"benchmark_locks($module, num_threads, use_pymutex=True,\n"
" critical_section_length=1, time_ms=1000, /)\n"
"--\n"
"\n");
#define _TESTINTERNALCAPI_BENCHMARK_LOCKS_METHODDEF \
{"benchmark_locks", _PyCFunction_CAST(_testinternalcapi_benchmark_locks), METH_FASTCALL, _testinternalcapi_benchmark_locks__doc__},
static PyObject *
_testinternalcapi_benchmark_locks_impl(PyObject *module,
Py_ssize_t num_threads,
int use_pymutex,
int critical_section_length,
int time_ms);
static PyObject *
_testinternalcapi_benchmark_locks(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
{
PyObject *return_value = NULL;
Py_ssize_t num_threads;
int use_pymutex = 1;
int critical_section_length = 1;
int time_ms = 1000;
if (!_PyArg_CheckPositional("benchmark_locks", nargs, 1, 4)) {
goto exit;
}
{
Py_ssize_t ival = -1;
PyObject *iobj = _PyNumber_Index(args[0]);
if (iobj != NULL) {
ival = PyLong_AsSsize_t(iobj);
Py_DECREF(iobj);
}
if (ival == -1 && PyErr_Occurred()) {
goto exit;
}
num_threads = ival;
}
if (nargs < 2) {
goto skip_optional;
}
use_pymutex = PyObject_IsTrue(args[1]);
if (use_pymutex < 0) {
goto exit;
}
if (nargs < 3) {
goto skip_optional;
}
critical_section_length = PyLong_AsInt(args[2]);
if (critical_section_length == -1 && PyErr_Occurred()) {
goto exit;
}
if (nargs < 4) {
goto skip_optional;
}
time_ms = PyLong_AsInt(args[3]);
if (time_ms == -1 && PyErr_Occurred()) {
goto exit;
}
skip_optional:
return_value = _testinternalcapi_benchmark_locks_impl(module, num_threads, use_pymutex, critical_section_length, time_ms);
exit:
return return_value;
}
/*[clinic end generated code: output=105105d759c0c271 input=a9049054013a1b77]*/