IPV6_ENABLED = _is_ipv6_enabled()
-# A constant likely larger than the underlying OS pipe buffer size.
-# Windows limit seems to be around 512B, and many Unix kernels have a 64K pipe
-# buffer size or 16*PAGE_SIZE: take a few megs to be sure. This
-PIPE_MAX_SIZE = 3 * 1000 * 1000
+# A constant likely larger than the underlying OS pipe buffer size, to
+# make writes blocking.
+# Windows limit seems to be around 512 B, and many Unix kernels have a
+# 64 KiB pipe buffer size or 16 * PAGE_SIZE: take a few megs to be sure.
+# (see issue #17835 for a discussion of this number).
+PIPE_MAX_SIZE = 4 *1024 * 1024 + 1
# decorator for skipping tests on non-IEEE 754 platforms
# The buffered IO layer must check for pending signal
# handlers, which in this case will invoke alarm_interrupt().
self.assertRaises(ZeroDivisionError,
- wio.write, item * (support.PIPE_MAX_SIZE // len(item)))
+ wio.write, item * (support.PIPE_MAX_SIZE // len(item) + 1))
t.join()
# We got one byte, get another one and check that it isn't a
# repeat of the first one.
select = support.import_module("select")
# A quantity that exceeds the buffer size of an anonymous pipe's
# write end.
- N = 1024 * 1024
+ N = support.PIPE_MAX_SIZE
r, w = os.pipe()
fdopen_kwargs["closefd"] = False
# We need a separate thread to read from the pipe and allow the
Tests
-----
+- Issue #17835: Fix test_io when the default OS pipe buffer size is larger
+ than one million bytes.
+
- Issue #17065: Use process-unique key for winreg tests to avoid failures if
test is run multiple times in parallel (eg: on a buildbot host).