[Python-checkins] [3.6] bpo-31786: Make functions in the select module blocking when timeout is a small negative value. (GH-4003). (#4022)
Serhiy Storchaka
webhook-mailer at python.org
Wed Oct 18 04:12:50 EDT 2017
https://github.com/python/cpython/commit/95602b368b87da3702a0f340ded2a23e823bb104
commit: 95602b368b87da3702a0f340ded2a23e823bb104
branch: 3.6
author: Pablo Galindo <Pablogsal at gmail.com>
committer: Serhiy Storchaka <storchaka at gmail.com>
date: 2017-10-18T11:12:47+03:00
summary:
[3.6] bpo-31786: Make functions in the select module blocking when timeout is a small negative value. (GH-4003). (#4022)
(cherry picked from commit 2c15b29aea5d6b9c61aa42d2c24a07ff1edb4b46)
files:
A Misc/NEWS.d/next/Core and Builtins/2017-10-15-23-44-57.bpo-31786.XwdEP4.rst
M Include/pytime.h
M Lib/test/test_poll.py
M Lib/test/test_time.py
M Modules/_testcapimodule.c
M Modules/selectmodule.c
M Python/pytime.c
diff --git a/Include/pytime.h b/Include/pytime.h
index 87ac7fcbbad..9e1f304fd48 100644
--- a/Include/pytime.h
+++ b/Include/pytime.h
@@ -29,9 +29,20 @@ typedef enum {
_PyTime_ROUND_CEILING=1,
/* Round to nearest with ties going to nearest even integer.
For example, used to round from a Python float. */
- _PyTime_ROUND_HALF_EVEN
+ _PyTime_ROUND_HALF_EVEN=2,
+ /* Round away from zero
+ For example, used for timeout. _PyTime_ROUND_CEILING rounds
+ -1e-9 to 0 milliseconds which causes bpo-31786 issue.
+ _PyTime_ROUND_UP rounds -1e-9 to -1 millisecond which keeps
+ the timeout sign as expected. select.poll(timeout) must block
+ for negative values." */
+ _PyTime_ROUND_UP=3,
+ /* _PyTime_ROUND_TIMEOUT (an alias for _PyTime_ROUND_UP) should be
+ used for timeouts. */
+ _PyTime_ROUND_TIMEOUT = _PyTime_ROUND_UP
} _PyTime_round_t;
+
/* Convert a time_t to a PyLong. */
PyAPI_FUNC(PyObject *) _PyLong_FromTime_t(
time_t sec);
diff --git a/Lib/test/test_poll.py b/Lib/test/test_poll.py
index 6a2bf6ea7b7..2a393601131 100644
--- a/Lib/test/test_poll.py
+++ b/Lib/test/test_poll.py
@@ -208,6 +208,28 @@ def test_threaded_poll(self):
os.write(w, b'spam')
t.join()
+ @unittest.skipUnless(threading, 'Threading required for this test.')
+ @reap_threads
+ def test_poll_blocks_with_negative_ms(self):
+ for timeout_ms in [None, -1, -1.0, -0.1, -1e-100]:
+ # Create two file descriptors. This will be used to unlock
+ # the blocking call to poll.poll inside the thread
+ r, w = os.pipe()
+ pollster = select.poll()
+ pollster.register(r, select.POLLIN)
+
+ poll_thread = threading.Thread(target=pollster.poll, args=(timeout_ms,))
+ poll_thread.start()
+ poll_thread.join(timeout=0.1)
+ self.assertTrue(poll_thread.is_alive())
+
+ # Write to the pipe so pollster.poll unblocks and the thread ends.
+ os.write(w, b'spam')
+ poll_thread.join()
+ self.assertFalse(poll_thread.is_alive())
+ os.close(r)
+ os.close(w)
+
def test_main():
run_unittest(PollTests)
diff --git a/Lib/test/test_time.py b/Lib/test/test_time.py
index 7093fc6a2ec..5b6e58fa557 100644
--- a/Lib/test/test_time.py
+++ b/Lib/test/test_time.py
@@ -36,6 +36,8 @@ class _PyTime(enum.IntEnum):
ROUND_CEILING = 1
# Round to nearest with ties going to nearest even integer
ROUND_HALF_EVEN = 2
+ # Round away from zero
+ ROUND_UP = 3
# Rounding modes supported by PyTime
ROUNDING_MODES = (
@@ -43,6 +45,7 @@ class _PyTime(enum.IntEnum):
(_PyTime.ROUND_FLOOR, decimal.ROUND_FLOOR),
(_PyTime.ROUND_CEILING, decimal.ROUND_CEILING),
(_PyTime.ROUND_HALF_EVEN, decimal.ROUND_HALF_EVEN),
+ (_PyTime.ROUND_UP, decimal.ROUND_UP),
)
diff --git a/Misc/NEWS.d/next/Core and Builtins/2017-10-15-23-44-57.bpo-31786.XwdEP4.rst b/Misc/NEWS.d/next/Core and Builtins/2017-10-15-23-44-57.bpo-31786.XwdEP4.rst
new file mode 100644
index 00000000000..f0326e30ecd
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2017-10-15-23-44-57.bpo-31786.XwdEP4.rst
@@ -0,0 +1,3 @@
+Fix timeout rounding in the select module to round correctly negative timeouts between -1.0 and 0.0.
+The functions now block waiting for events as expected. Previously, the call was incorrectly non-blocking.
+Patch by Pablo Galindo.
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index ede675da285..2eda03cb73a 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -3016,7 +3016,8 @@ check_time_rounding(int round)
{
if (round != _PyTime_ROUND_FLOOR
&& round != _PyTime_ROUND_CEILING
- && round != _PyTime_ROUND_HALF_EVEN) {
+ && round != _PyTime_ROUND_HALF_EVEN
+ && round != _PyTime_ROUND_UP) {
PyErr_SetString(PyExc_ValueError, "invalid rounding");
return -1;
}
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
index 4a7fe002f0b..9ae583be244 100644
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -213,7 +213,7 @@ select_select(PyObject *self, PyObject *args)
tvp = (struct timeval *)NULL;
else {
if (_PyTime_FromSecondsObject(&timeout, timeout_obj,
- _PyTime_ROUND_CEILING) < 0) {
+ _PyTime_ROUND_TIMEOUT) < 0) {
if (PyErr_ExceptionMatches(PyExc_TypeError)) {
PyErr_SetString(PyExc_TypeError,
"timeout must be a float or None");
@@ -221,7 +221,7 @@ select_select(PyObject *self, PyObject *args)
return NULL;
}
- if (_PyTime_AsTimeval(timeout, &tv, _PyTime_ROUND_CEILING) == -1)
+ if (_PyTime_AsTimeval(timeout, &tv, _PyTime_ROUND_TIMEOUT) == -1)
return NULL;
if (tv.tv_sec < 0) {
PyErr_SetString(PyExc_ValueError, "timeout must be non-negative");
@@ -543,7 +543,7 @@ poll_poll(pollObject *self, PyObject *args)
}
else {
if (_PyTime_FromMillisecondsObject(&timeout, timeout_obj,
- _PyTime_ROUND_CEILING) < 0) {
+ _PyTime_ROUND_TIMEOUT) < 0) {
if (PyErr_ExceptionMatches(PyExc_TypeError)) {
PyErr_SetString(PyExc_TypeError,
"timeout must be an integer or None");
@@ -551,7 +551,7 @@ poll_poll(pollObject *self, PyObject *args)
return NULL;
}
- ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
+ ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_TIMEOUT);
if (ms < INT_MIN || ms > INT_MAX) {
PyErr_SetString(PyExc_OverflowError, "timeout is too large");
return NULL;
@@ -899,7 +899,7 @@ devpoll_poll(devpollObject *self, PyObject *args)
}
else {
if (_PyTime_FromMillisecondsObject(&timeout, timeout_obj,
- _PyTime_ROUND_CEILING) < 0) {
+ _PyTime_ROUND_TIMEOUT) < 0) {
if (PyErr_ExceptionMatches(PyExc_TypeError)) {
PyErr_SetString(PyExc_TypeError,
"timeout must be an integer or None");
@@ -907,7 +907,7 @@ devpoll_poll(devpollObject *self, PyObject *args)
return NULL;
}
- ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
+ ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_TIMEOUT);
if (ms < -1 || ms > INT_MAX) {
PyErr_SetString(PyExc_OverflowError, "timeout is too large");
return NULL;
@@ -1514,7 +1514,7 @@ pyepoll_poll(pyEpoll_Object *self, PyObject *args, PyObject *kwds)
/* epoll_wait() has a resolution of 1 millisecond, round towards
infinity to wait at least timeout seconds. */
if (_PyTime_FromSecondsObject(&timeout, timeout_obj,
- _PyTime_ROUND_CEILING) < 0) {
+ _PyTime_ROUND_TIMEOUT) < 0) {
if (PyErr_ExceptionMatches(PyExc_TypeError)) {
PyErr_SetString(PyExc_TypeError,
"timeout must be an integer or None");
@@ -2129,7 +2129,7 @@ kqueue_queue_control(kqueue_queue_Object *self, PyObject *args)
}
else {
if (_PyTime_FromSecondsObject(&timeout,
- otimeout, _PyTime_ROUND_CEILING) < 0) {
+ otimeout, _PyTime_ROUND_TIMEOUT) < 0) {
PyErr_Format(PyExc_TypeError,
"timeout argument must be a number "
"or None, got %.200s",
diff --git a/Python/pytime.c b/Python/pytime.c
index b416eff6b29..19fdb55b066 100644
--- a/Python/pytime.c
+++ b/Python/pytime.c
@@ -84,12 +84,19 @@ _PyTime_Round(double x, _PyTime_round_t round)
volatile double d;
d = x;
- if (round == _PyTime_ROUND_HALF_EVEN)
+ if (round == _PyTime_ROUND_HALF_EVEN){
d = _PyTime_RoundHalfEven(d);
- else if (round == _PyTime_ROUND_CEILING)
+ }
+ else if (round == _PyTime_ROUND_CEILING){
d = ceil(d);
- else
+ }
+ else if (round == _PyTime_ROUND_FLOOR) {
d = floor(d);
+ }
+ else {
+ assert(round == _PyTime_ROUND_UP);
+ d = (d >= 0.0) ? ceil(d) : floor(d);
+ }
return d;
}
@@ -395,16 +402,29 @@ _PyTime_Divide(const _PyTime_t t, const _PyTime_t k,
return x;
}
else if (round == _PyTime_ROUND_CEILING) {
- if (t >= 0)
+ if (t >= 0){
return (t + k - 1) / k;
- else
+ }
+ else{
return t / k;
+ }
}
- else {
- if (t >= 0)
+ else if (round == _PyTime_ROUND_FLOOR){
+ if (t >= 0) {
return t / k;
- else
+ }
+ else{
return (t - (k - 1)) / k;
+ }
+ }
+ else {
+ assert(round == _PyTime_ROUND_UP);
+ if (t >= 0) {
+ return (t + k - 1) / k;
+ }
+ else {
+ return (t - (k - 1)) / k;
+ }
}
}
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