/* Helper to acquire an interruptible lock with a timeout. If the lock acquire
* is interrupted, signal handlers are run, and if they raise an exception,
* PY_LOCK_INTR is returned. Otherwise, PY_LOCK_ACQUIRED or PY_LOCK_FAILURE
* are returned, depending on whether the lock can be acquired within the
* timeout.
*/
static PyLockStatus
acquire_timed(PyThread_type_lock lock, _PyTime_t timeout)
{
PyLockStatus r;
_PyTime_t endtime = 0;
_PyTime_t microseconds;
if (timeout > 0)
endtime = _PyTime_GetMonotonicClock() + timeout;
do {
microseconds = _PyTime_AsMicroseconds(timeout, _PyTime_ROUND_CEILING);
/* first a simple non-blocking try without releasing the GIL */
r = PyThread_acquire_lock_timed(lock, 0, 0);
if (r == PY_LOCK_FAILURE && microseconds != 0) {
Py_BEGIN_ALLOW_THREADS
r = PyThread_acquire_lock_timed(lock, microseconds, 1);
Py_END_ALLOW_THREADS
}
if (r == PY_LOCK_INTR) {
/* Run signal handlers if we were interrupted. Propagate
* exceptions from signal handlers, such as KeyboardInterrupt, by
* passing up PY_LOCK_INTR. */
if (Py_MakePendingCalls() < 0) {
return PY_LOCK_INTR;
}
/* If we're using a timeout, recompute the timeout after processing
* signals, since those can take time. */
if (timeout > 0) {
timeout = endtime - _PyTime_GetMonotonicClock();
/* Check for negative values, since those mean block forever.
*/
if (timeout < 0) {
r = PY_LOCK_FAILURE;
}
}
}
} while (r == PY_LOCK_INTR); /* Retry if we were interrupted. */
int main()
{
if (_PyTime_AsMicroseconds (10000, _PyTime_ROUND_FLOOR) != 10)
abort ();
return 0;
}
static PyObject *
_queue_SimpleQueue_get_impl(simplequeueobject *self, int block,
PyObject *timeout)
/*[clinic end generated code: output=ec82a7157dcccd1a input=4bf691f9f01fa297]*/
{
_PyTime_t endtime = 0;
_PyTime_t timeout_val;
PyObject *item;
PyLockStatus r;
PY_TIMEOUT_T microseconds;
if (block == 0) {
/* Non-blocking */
microseconds = 0;
}
else if (timeout != Py_None) {
/* With timeout */
if (_PyTime_FromSecondsObject(&timeout_val,
timeout, _PyTime_ROUND_CEILING) < 0)
return NULL;
if (timeout_val < 0) {
PyErr_SetString(PyExc_ValueError,
"'timeout' must be a non-negative number");
return NULL;
}
microseconds = _PyTime_AsMicroseconds(timeout_val,
_PyTime_ROUND_CEILING);
if (microseconds >= PY_TIMEOUT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"timeout value is too large");
return NULL;
}
endtime = _PyTime_GetMonotonicClock() + timeout_val;
}
else {
/* Infinitely blocking */
microseconds = -1;
}
/* put() signals the queue to be non-empty by releasing the lock.
* So we simply try to acquire the lock in a loop, until the condition
* (queue non-empty) becomes true.
*/
while (self->lst_pos == PyList_GET_SIZE(self->lst)) {
/* First a simple non-blocking try without releasing the GIL */
r = PyThread_acquire_lock_timed(self->lock, 0, 0);
if (r == PY_LOCK_FAILURE && microseconds != 0) {
Py_BEGIN_ALLOW_THREADS
r = PyThread_acquire_lock_timed(self->lock, microseconds, 1);
Py_END_ALLOW_THREADS
}
if (r == PY_LOCK_INTR && Py_MakePendingCalls() < 0) {
return NULL;
}
if (r == PY_LOCK_FAILURE) {
/* Timed out */
PyErr_SetNone(EmptyError);
return NULL;
}
self->locked = 1;
/* Adjust timeout for next iteration (if any) */
if (endtime > 0) {
timeout_val = endtime - _PyTime_GetMonotonicClock();
microseconds = _PyTime_AsMicroseconds(timeout_val, _PyTime_ROUND_CEILING);
}
}
