From 5c65834d801d6b4313eef0684a30e12c22ccfedd Mon Sep 17 00:00:00 2001 From: "Miss Islington (bot)" <31488909+miss-islington@users.noreply.github.com> Date: Thu, 9 Sep 2021 06:40:42 -0700 Subject: bpo-44219: Release the GIL during isatty syscalls (GH-28250) Release the GIL while performing isatty() system calls on arbitrary file descriptors. In particular, this affects os.isatty(), os.device_encoding() and io.TextIOWrapper. By extension, io.open() in text mode is also affected. (cherry picked from commit 06148b1870fceb1a21738761b8e1ac3bf654319b) Co-authored-by: Vincent Michel --- Python/fileutils.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'Python/fileutils.c') diff --git a/Python/fileutils.c b/Python/fileutils.c index 11c659d5a4..d072363535 100644 --- a/Python/fileutils.c +++ b/Python/fileutils.c @@ -69,9 +69,11 @@ _Py_device_encoding(int fd) UINT cp; #endif int valid; + Py_BEGIN_ALLOW_THREADS _Py_BEGIN_SUPPRESS_IPH valid = isatty(fd); _Py_END_SUPPRESS_IPH + Py_END_ALLOW_THREADS if (!valid) Py_RETURN_NONE; @@ -1737,12 +1739,22 @@ _Py_write_impl(int fd, const void *buf, size_t count, int gil_held) _Py_BEGIN_SUPPRESS_IPH #ifdef MS_WINDOWS - if (count > 32767 && isatty(fd)) { + if (count > 32767) { /* Issue #11395: the Windows console returns an error (12: not enough space error) on writing into stdout if stdout mode is binary and the length is greater than 66,000 bytes (or less, depending on heap usage). */ - count = 32767; + if (gil_held) { + Py_BEGIN_ALLOW_THREADS + if (isatty(fd)) { + count = 32767; + } + Py_END_ALLOW_THREADS + } else { + if (isatty(fd)) { + count = 32767; + } + } } #endif if (count > _PY_WRITE_MAX) { -- cgit v1.2.1