bitbake: bitbake: Add parsing torture test

Adds a contrib/ script that repeatedly runs bitbake and interrupts
parsing to try and reproduce parsing deadlocks.

(Bitbake rev: 0457482e252f216618a6fccad0030fcd6c5a304f)

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/contrib/bbparse-torture.py

@@ -0,0 +1,89 @@
+#! /usr/bin/env python3
+#
+# Copyright (C) 2020 Joshua Watt <JPEWhacker@gmail.com>
+#
+# SPDX-License-Identifier: MIT
+
+import argparse
+import os
+import random
+import shutil
+import signal
+import subprocess
+import sys
+import time
+
+
+def try_unlink(path):
+    try:
+        os.unlink(path)
+    except:
+        pass
+
+
+def main():
+    def cleanup():
+        shutil.rmtree("tmp/cache", ignore_errors=True)
+        try_unlink("bitbake-cookerdaemon.log")
+        try_unlink("bitbake.sock")
+        try_unlink("bitbake.lock")
+
+    parser = argparse.ArgumentParser(
+        description="Bitbake parser torture test",
+        epilog="""
+        A torture test for bitbake's parser. Repeatedly interrupts parsing until
+        bitbake decides to deadlock.
+        """,
+    )
+
+    args = parser.parse_args()
+
+    if not "BUILDDIR" in os.environ:
+        print(
+            "'BUILDDIR' not found in the environment. Did you initialize the build environment?"
+        )
+        return 1
+
+    os.chdir(os.environ["BUILDDIR"])
+
+    run_num = 0
+    while True:
+        if run_num % 100 == 0:
+            print("Calibrating wait time...")
+            cleanup()
+
+            start_time = time.monotonic()
+            r = subprocess.run(["bitbake", "-p"])
+            max_wait_time = time.monotonic() - start_time
+
+            if r.returncode != 0:
+                print("Calibration run exited with %d" % r.returncode)
+                return 1
+
+            print("Maximum wait time is %f seconds" % max_wait_time)
+
+        run_num += 1
+        wait_time = random.random() * max_wait_time
+
+        print("Run #%d" % run_num)
+        print("Will sleep for %f seconds" % wait_time)
+
+        cleanup()
+        with subprocess.Popen(["bitbake", "-p"]) as proc:
+            time.sleep(wait_time)
+            proc.send_signal(signal.SIGINT)
+            try:
+                proc.wait(45)
+            except subprocess.TimeoutExpired:
+                print("Run #%d: Waited too long. Possible deadlock!" % run_num)
+                proc.wait()
+                return 1
+
+            if proc.returncode == 0:
+                print("Exited successfully. Timeout too long?")
+            else:
+                print("Exited with %d" % proc.returncode)
+
+
+if __name__ == "__main__":
+    sys.exit(main())