Vincent Michel <vxgmic...@gmail.com> added the comment:
My team ran into this issue while developing a fuse application too. In an effort to help this issue move forward, I tried to list all occurrences of the `isatty` C function in the cpython code base. I found 14 of them. 9 of them are directly related to stdin/stdout/stderr, so it's probably not crucial to release the GIL for those occurrences: - `main.c:stdin_is_interactive` - `main.c:pymain_import_readline` - `readline.c:setup_readline` - `bltinmodule.c:builtin_input_impl` (x2) - `frozenmain.c:Py_FrozenMain` - `pylifecycle.c:Py_FdIsInteractive` (x2) - `fileobject.c:stdprinter_isatty` (GIL is actually released for this one) Out of the remaining 4, only 1 releases the GIL: - `fileio.c:_io_FileIO_isatty_impl`: used for `FileIO.isatty` Which gives 3 occurrences of non-stdstream specific usage of `isatty` that do not release the GIL: - `posixmodule.c:os_isatty_impl`: used by `os.isatty` - `fileutils.c:_Py_device_encoding`: used `TextIOWrapper.__init__` - `fileutils.c:_Py_write_impl`: windows specific, issue #11395 The first one is used by `os.isatty` which means this call can also deadlock. I did manage to reproduce it with a simple fuse loopback file system: https://github.com/fusepy/fusepy/blob/master/examples/loopback.py The second one is the one found by @smurfix and gets triggered when `io.open()` is used in text mode. The third one only triggers on windows when writing more than 32767 bytes to a file descriptor. A comment points to issue #11395 (https://bugs.python.org/issue11395). Also, it seems from the function signature that this function might be called with or without the GIL held, which might cause the fix to be a bit more complicated than the first two use cases. I hope this helps. ---------- nosy: +vxgmichel _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue44219> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
