[interactive] Replace set_pipe_size by Popen(pipesize=...), because we now require Py3.10

Author: mpsijm

bin/interactive.py

@@ -186,15 +186,6 @@ def get_validator_command():
     # - Close remaining program + write end of pipe
     # - Close remaining read end of pipes
 
-    def set_pipe_size(pipe):
-        # Somehow, setting the pipe buffer size is necessary to avoid hanging in larger interactions.
-        # Note that this is equivalent to Popen's `pipesize` argument in Python 3.10,
-        # but we backported this for compatibility with older Python versions:
-        # https://github.com/python/cpython/pull/21921/files#diff-619941af4b328b6abf2dc02c54e774fc17acc1ac4172c14db27d6097cbbff92aR1590
-        # See also: https://github.com/RagnarGrootKoerkamp/BAPCtools/pull/251#issuecomment-1609353538
-        # Note: 1031 = fcntl.F_SETPIPE_SZ, but that constant is also only available in Python 3.10.
-        fcntl.fcntl(pipe, 1031, BUFFER_SIZE)
-
     interaction_file = None
     # TODO: Print interaction when needed.
     if interaction and interaction is not True:
@@ -231,6 +222,7 @@ def set_pipe_size(pipe):
             # TODO: Make a flag to pass validator error directly to terminal.
             stderr=subprocess.PIPE if validator_error is False else None,
             cwd=validator_dir,
+            pipesize=BUFFER_SIZE,
             preexec_fn=limit_setter(validator_command, validator_timeout, None, 0),
         )
         validator_pid = validator.pid
@@ -240,17 +232,13 @@ def set_pipe_size(pipe):
 
         assert validator.stdin and validator.stdout
 
-        set_pipe_size(validator.stdin)
-        set_pipe_size(validator.stdout)
-        if validator_error is False:
-            set_pipe_size(validator.stderr)
-
         if interaction:
             team_tee = subprocess.Popen(
                 ['python3', '-c', TEE_CODE, '>'],
                 stdin=subprocess.PIPE,
                 stdout=validator.stdin,
                 stderr=interaction_file,
+                pipesize=BUFFER_SIZE,
                 preexec_fn=limit_setter(None, None, None, gid),
             )
             team_tee_pid = team_tee.pid
@@ -259,28 +247,24 @@ def set_pipe_size(pipe):
                 stdin=validator.stdout,
                 stdout=subprocess.PIPE,
                 stderr=interaction_file,
+                pipesize=BUFFER_SIZE,
                 preexec_fn=limit_setter(None, None, None, gid),
             )
             val_tee_pid = val_tee.pid
 
-            set_pipe_size(team_tee.stdin)
-            set_pipe_size(val_tee.stdout)
-
         submission = subprocess.Popen(
             submission_command,
             stdin=(val_tee if interaction else validator).stdout,
             stdout=(team_tee if interaction else validator).stdin,
             stderr=subprocess.PIPE if team_error is False else None,
             cwd=submission_dir,
+            pipesize=BUFFER_SIZE,
             preexec_fn=limit_setter(submission_command, timeout, memory_limit, gid),
         )
         submission_pid = submission.pid
 
         assert validator.stderr and submission.stderr
 
-        if team_error is False:
-            set_pipe_size(submission.stderr)
-
         stop_kill_handler = threading.Event()
         submission_time: Optional[float] = None