gh-117721: use PyMutex in `_thread.lock` (#125110)

This commit is contained in:
Kumar Aditya 2024-10-08 20:17:32 +05:30 committed by GitHub
parent c203955f3b
commit fca552993d
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GPG Key ID: B5690EEEBB952194
1 changed files with 11 additions and 45 deletions

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@ -705,9 +705,7 @@ static PyType_Spec ThreadHandle_Type_spec = {
typedef struct {
PyObject_HEAD
PyThread_type_lock lock_lock;
PyObject *in_weakreflist;
char locked; /* for sanity checking */
PyMutex lock;
} lockobject;
static int
@ -722,15 +720,7 @@ lock_dealloc(PyObject *op)
{
lockobject *self = (lockobject*)op;
PyObject_GC_UnTrack(self);
if (self->in_weakreflist != NULL) {
PyObject_ClearWeakRefs((PyObject *) self);
}
if (self->lock_lock != NULL) {
/* Unlock the lock so it's safe to free it */
if (self->locked)
PyThread_release_lock(self->lock_lock);
PyThread_free_lock(self->lock_lock);
}
PyObject_ClearWeakRefs((PyObject *) self);
PyTypeObject *tp = Py_TYPE(self);
tp->tp_free((PyObject*)self);
Py_DECREF(tp);
@ -798,13 +788,12 @@ lock_PyThread_acquire_lock(PyObject *op, PyObject *args, PyObject *kwds)
return NULL;
}
PyLockStatus r = acquire_timed(self->lock_lock, timeout);
PyLockStatus r = _PyMutex_LockTimed(&self->lock, timeout,
_PY_LOCK_HANDLE_SIGNALS | _PY_LOCK_DETACH);
if (r == PY_LOCK_INTR) {
return NULL;
}
if (r == PY_LOCK_ACQUIRED)
self->locked = 1;
return PyBool_FromLong(r == PY_LOCK_ACQUIRED);
}
@ -836,13 +825,11 @@ lock_PyThread_release_lock(PyObject *op, PyObject *Py_UNUSED(ignored))
{
lockobject *self = (lockobject*)op;
/* Sanity check: the lock must be locked */
if (!self->locked) {
if (_PyMutex_TryUnlock(&self->lock) < 0) {
PyErr_SetString(ThreadError, "release unlocked lock");
return NULL;
}
self->locked = 0;
PyThread_release_lock(self->lock_lock);
Py_RETURN_NONE;
}
@ -870,7 +857,7 @@ static PyObject *
lock_locked_lock(PyObject *op, PyObject *Py_UNUSED(ignored))
{
lockobject *self = (lockobject*)op;
return PyBool_FromLong((long)self->locked);
return PyBool_FromLong(PyMutex_IsLocked(&self->lock));
}
PyDoc_STRVAR(locked_doc,
@ -890,21 +877,15 @@ lock_repr(PyObject *op)
{
lockobject *self = (lockobject*)op;
return PyUnicode_FromFormat("<%s %s object at %p>",
self->locked ? "locked" : "unlocked", Py_TYPE(self)->tp_name, self);
PyMutex_IsLocked(&self->lock) ? "locked" : "unlocked", Py_TYPE(self)->tp_name, self);
}
#ifdef HAVE_FORK
static PyObject *
lock__at_fork_reinit(PyObject *op, PyObject *Py_UNUSED(args))
{
lockobject *self = (lockobject*)op;
if (_PyThread_at_fork_reinit(&self->lock_lock) < 0) {
PyErr_SetString(ThreadError, "failed to reinitialize lock at fork");
return NULL;
}
self->locked = 0;
lockobject *self = (lockobject *)op;
_PyMutex_at_fork_reinit(&self->lock);
Py_RETURN_NONE;
}
#endif /* HAVE_FORK */
@ -970,18 +951,12 @@ A lock is not owned by the thread that locked it; another thread may\n\
unlock it. A thread attempting to lock a lock that it has already locked\n\
will block until another thread unlocks it. Deadlocks may ensue.");
static PyMemberDef lock_type_members[] = {
{"__weaklistoffset__", Py_T_PYSSIZET, offsetof(lockobject, in_weakreflist), Py_READONLY},
{NULL},
};
static PyType_Slot lock_type_slots[] = {
{Py_tp_dealloc, lock_dealloc},
{Py_tp_repr, lock_repr},
{Py_tp_doc, (void *)lock_doc},
{Py_tp_methods, lock_methods},
{Py_tp_traverse, lock_traverse},
{Py_tp_members, lock_type_members},
{Py_tp_new, lock_new},
{0, 0}
};
@ -990,7 +965,7 @@ static PyType_Spec lock_type_spec = {
.name = "_thread.lock",
.basicsize = sizeof(lockobject),
.flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
Py_TPFLAGS_IMMUTABLETYPE),
Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_MANAGED_WEAKREF),
.slots = lock_type_slots,
};
@ -1340,16 +1315,7 @@ newlockobject(PyObject *module)
if (self == NULL) {
return NULL;
}
self->lock_lock = PyThread_allocate_lock();
self->locked = 0;
self->in_weakreflist = NULL;
if (self->lock_lock == NULL) {
Py_DECREF(self);
PyErr_SetString(ThreadError, "can't allocate lock");
return NULL;
}
self->lock = (PyMutex){0};
return self;
}