From 58111b18adbe399301e35bd022cd47bbee458613 Mon Sep 17 00:00:00 2001
From: Guillaume Chanel <Guillaume.Chanel@unige.ch>
Date: Tue, 7 Feb 2023 17:59:20 +0100
Subject: [PATCH] Add pipe test with more data than the pipe size
Several students implemented the pipe in two steps:
- write all
- read all
This test was designed to detect this problem
---
test/test.py | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/test/test.py b/test/test.py
index b7c99f0..0f5da28 100755
--- a/test/test.py
+++ b/test/test.py
@@ -22,6 +22,8 @@ import time
from pathlib import Path
import psutil
from colorama import Fore
+import random
+import string
def print_usage():
@@ -155,7 +157,7 @@ class Shell:
# Kill the children and raise timeout error
for c in children:
c.kill()
- raise psutil.TimeoutExpired('The process took more than the timeout ({}s) to terminate (last command executed: {})'.format(duration, self.last_cmd))
+ raise TimeoutError('The process took more than timeout ({:.2f}s) to terminate (last command executed: {})'.format(duration, self.last_cmd))
def exec_command(self, command: Cmd, wait_cmd: bool = True, timeout: int = 3):
@@ -401,6 +403,7 @@ class Test:
shell.exit()
+
@test
def test_pipe(self):
# Working commands
@@ -415,6 +418,21 @@ class Test:
shell.exec_commands([cmd])
self._test_command_results(cmd, shell, test_stdout='notest', test_stderr='include', test_return=False, test_in_shell=True)
+ # Test a pipe with a high quantity of data
+ # The idea is to ensure that both processes are running concurrently
+ # If not, the writing end of the pipe should block since its capacity has been exceeded and no read occurs
+ LINUX_PIPE_SIZE = 65536
+ with tempfile.NamedTemporaryFile("wt") as f:
+ f.writelines(random.choices(string.ascii_letters, k=2*LINUX_PIPE_SIZE))
+ cmd = Cmd(['cat', f.name, '|', 'grep', 'word'])
+ shell = Shell(self.shell_exec)
+ try:
+ shell.exec_commands([cmd])
+ except TimeoutError as e:
+ raise TimeoutError(str(e) + '. This happened when trying to communicate more data than the size of the pipe. Probably the write side of the pipe blocked because the other side was not read.')
+
+
+
@test
def test_background_jobs(self):
# Check possibility to have two processes running
--
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