/* 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. */
static int
pysleep(_PyTime_t secs)
{
_PyTime_t deadline, monotonic;
#ifndef MS_WINDOWS
struct timeval timeout;
int err = 0;
#else
_PyTime_t millisecs;
unsigned long ul_millis;
DWORD rc;
HANDLE hInterruptEvent;
#endif
deadline = _PyTime_GetMonotonicClock() + secs;
do {
#ifndef MS_WINDOWS
if (_PyTime_AsTimeval(secs, &timeout, _PyTime_ROUND_CEILING) < 0)
return -1;
Py_BEGIN_ALLOW_THREADS
err = select(0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &timeout);
Py_END_ALLOW_THREADS
if (err == 0)
break;
if (errno != EINTR) {
PyErr_SetFromErrno(PyExc_OSError);
return -1;
}
#else
millisecs = _PyTime_AsMilliseconds(secs, _PyTime_ROUND_CEILING);
if (millisecs > (double)ULONG_MAX) {
PyErr_SetString(PyExc_OverflowError,
"sleep length is too large");
return -1;
}
/* Allow sleep(0) to maintain win32 semantics, and as decreed
* by Guido, only the main thread can be interrupted.
*/
ul_millis = (unsigned long)millisecs;
if (ul_millis == 0 || !_PyOS_IsMainThread()) {
Py_BEGIN_ALLOW_THREADS
Sleep(ul_millis);
Py_END_ALLOW_THREADS
break;
}
hInterruptEvent = _PyOS_SigintEvent();
ResetEvent(hInterruptEvent);
Py_BEGIN_ALLOW_THREADS
rc = WaitForSingleObjectEx(hInterruptEvent, ul_millis, FALSE);
Py_END_ALLOW_THREADS
if (rc != WAIT_OBJECT_0)
break;
#endif
/* sleep was interrupted by SIGINT */
if (PyErr_CheckSignals())
return -1;
monotonic = _PyTime_GetMonotonicClock();
secs = deadline - monotonic;
if (secs < 0)
break;
/* retry with the recomputed delay */
} while (1);
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);
}
}
