Merged revisions 88610 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k
........
r88610 | antoine.pitrou | 2011-02-25 22:24:11 +0100 (ven., 25 févr. 2011) | 4 lines
Issue #10956: Buffered I/O classes retry reading or writing after a signal
has arrived and the handler returned successfully.
........
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index a25d9af..b665a6c 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -2622,7 +2622,8 @@
@unittest.skipUnless(threading, 'Threading required for this test.')
def check_interrupted_write(self, item, bytes, **fdopen_kwargs):
"""Check that a partial write, when it gets interrupted, properly
- invokes the signal handler."""
+ invokes the signal handler, and bubbles up the exception raised
+ in the latter."""
read_results = []
def _read():
s = os.read(r, 1)
@@ -2701,6 +2702,98 @@
def test_reentrant_write_text(self):
self.check_reentrant_write("xy", mode="w", encoding="ascii")
+ def check_interrupted_read_retry(self, decode, **fdopen_kwargs):
+ """Check that a buffered read, when it gets interrupted (either
+ returning a partial result or EINTR), properly invokes the signal
+ handler and retries if the latter returned successfully."""
+ r, w = os.pipe()
+ fdopen_kwargs["closefd"] = False
+ def alarm_handler(sig, frame):
+ os.write(w, b"bar")
+ signal.signal(signal.SIGALRM, alarm_handler)
+ try:
+ rio = self.io.open(r, **fdopen_kwargs)
+ os.write(w, b"foo")
+ signal.alarm(1)
+ # Expected behaviour:
+ # - first raw read() returns partial b"foo"
+ # - second raw read() returns EINTR
+ # - third raw read() returns b"bar"
+ self.assertEqual(decode(rio.read(6)), "foobar")
+ finally:
+ rio.close()
+ os.close(w)
+ os.close(r)
+
+ def test_interrupterd_read_retry_buffered(self):
+ self.check_interrupted_read_retry(lambda x: x.decode('latin1'),
+ mode="rb")
+
+ def test_interrupterd_read_retry_text(self):
+ self.check_interrupted_read_retry(lambda x: x,
+ mode="r")
+
+ @unittest.skipUnless(threading, 'Threading required for this test.')
+ def check_interrupted_write_retry(self, item, **fdopen_kwargs):
+ """Check that a buffered write, when it gets interrupted (either
+ returning a partial result or EINTR), properly invokes the signal
+ handler and retries if the latter returned successfully."""
+ select = support.import_module("select")
+ # A quantity that exceeds the buffer size of an anonymous pipe's
+ # write end.
+ N = 1024 * 1024
+ r, w = os.pipe()
+ fdopen_kwargs["closefd"] = False
+ # We need a separate thread to read from the pipe and allow the
+ # write() to finish. This thread is started after the SIGALRM is
+ # received (forcing a first EINTR in write()).
+ read_results = []
+ write_finished = False
+ def _read():
+ while not write_finished:
+ while r in select.select([r], [], [], 1.0)[0]:
+ s = os.read(r, 1024)
+ read_results.append(s)
+ t = threading.Thread(target=_read)
+ t.daemon = True
+ def alarm1(sig, frame):
+ signal.signal(signal.SIGALRM, alarm2)
+ signal.alarm(1)
+ def alarm2(sig, frame):
+ t.start()
+ signal.signal(signal.SIGALRM, alarm1)
+ try:
+ wio = self.io.open(w, **fdopen_kwargs)
+ signal.alarm(1)
+ # Expected behaviour:
+ # - first raw write() is partial (because of the limited pipe buffer
+ # and the first alarm)
+ # - second raw write() returns EINTR (because of the second alarm)
+ # - subsequent write()s are successful (either partial or complete)
+ self.assertEqual(N, wio.write(item * N))
+ wio.flush()
+ write_finished = True
+ t.join()
+ self.assertEqual(N, sum(len(x) for x in read_results))
+ finally:
+ write_finished = True
+ os.close(w)
+ os.close(r)
+ # This is deliberate. If we didn't close the file descriptor
+ # before closing wio, wio would try to flush its internal
+ # buffer, and could block (in case of failure).
+ try:
+ wio.close()
+ except IOError as e:
+ if e.errno != errno.EBADF:
+ raise
+
+ def test_interrupterd_write_retry_buffered(self):
+ self.check_interrupted_write_retry(b"x", mode="wb")
+
+ def test_interrupterd_write_retry_text(self):
+ self.check_interrupted_write_retry("x", mode="w", encoding="latin1")
+
class CSignalsTest(SignalsTest):
io = io