Issue #12196: Add PIPE_MAX_SIZE to test.support, constant larger than the
underlying OS pipe buffer size.
diff --git a/Lib/test/support.py b/Lib/test/support.py
index b03069c..6724e9b 100644
--- a/Lib/test/support.py
+++ b/Lib/test/support.py
@@ -48,7 +48,7 @@
"threading_cleanup", "reap_children", "cpython_only", "check_impl_detail",
"get_attribute", "swap_item", "swap_attr", "requires_IEEE_754",
"TestHandler", "Matcher", "can_symlink", "skip_unless_symlink",
- "import_fresh_module", "requires_zlib"
+ "import_fresh_module", "requires_zlib", "PIPE_MAX_SIZE"
]
class Error(Exception):
@@ -409,6 +409,13 @@
IPV6_ENABLED = _is_ipv6_enabled()
+
+# A constant likely larger than the underlying OS pipe buffer size.
+# Windows limit seems to be around 512B, and most Unix kernels have a 64K pipe
+# buffer size: take 1M to be sure.
+PIPE_MAX_SIZE = 1024 * 1024
+
+
# decorator for skipping tests on non-IEEE 754 platforms
requires_IEEE_754 = unittest.skipUnless(
float.__getformat__("double").startswith("IEEE"),