Issue #2489: Fix bug in _copy loop that could consume 100% cpu on EOF.
diff --git a/Lib/pty.py b/Lib/pty.py
index 810ebd8..3ccf619 100644
--- a/Lib/pty.py
+++ b/Lib/pty.py
@@ -142,15 +142,21 @@
Copies
pty master -> standard output (master_read)
standard input -> pty master (stdin_read)"""
- while 1:
- rfds, wfds, xfds = select(
- [master_fd, STDIN_FILENO], [], [])
+ fds = [master_fd, STDIN_FILENO]
+ while True:
+ rfds, wfds, xfds = select(fds, [], [])
if master_fd in rfds:
data = master_read(master_fd)
- os.write(STDOUT_FILENO, data)
+ if not data: # Reached EOF.
+ fds.remove(master_fd)
+ else:
+ os.write(STDOUT_FILENO, data)
if STDIN_FILENO in rfds:
data = stdin_read(STDIN_FILENO)
- _writen(master_fd, data)
+ if not data:
+ fds.remove(STDIN_FILENO)
+ else:
+ _writen(master_fd, data)
def spawn(argv, master_read=_read, stdin_read=_read):
"""Create a spawned process."""