kill-bb: Add it for killing abnormal bitbake processes

There might be processes left after Ctr-C, e.g.:
$ rm -f tmp/cache/default-glibc/qemux86/x86_64/
$ bitbake -p

Press 'Ctrl-C' multiple times during parsing, then bitbake processes may not
exit, and the worse is that we can't start bitbake again, we can't always
reproduce this, but sometime. We can only use "ps ux" to find the processes and
kill them one by one. This tool can kill all of them easily.

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>

diff --git a/scripts/kill-bb b/scripts/kill-bb
new file mode 100755 (executable)
index 0000000..0875b2c
--- /dev/null
+++ b/scripts/kill-bb
@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+#
+# Kill bitbake processes if the process' cwd == cwd
+#
+# Copyright (c) 2019 Wind River Systems, Inc.
+#
+# SPDX-License-Identifier: GPL-2.0-only
+#
+
+import os
+import sys
+import re
+
+pids = [pid for pid in os.listdir('/proc') if pid.isdigit()]
+
+bb_pids = []
+cwd =os.getcwd()
+for pid in pids:
+    cmdline_path = os.path.join('/proc', pid, 'cmdline')
+    pid_cwd = os.path.join('/proc', pid, 'cwd')
+    if os.path.exists(cmdline_path) and os.path.exists(pid_cwd):
+        pid_cwd = os.readlink(pid_cwd)
+        with open(cmdline_path, 'r') as f:
+            cmdline = f.read()
+            # Kill the bitbake process if its cwd == cwd
+            if re.match('python3.*/bitbake/bin/bitbake', cmdline) and pid_cwd == cwd:
+                bb_pids.append(pid)
+
+if not bb_pids:
+    print('No bitbake processes found in current working dir')
+    sys.exit(0)
+
+for pid in bb_pids:
+    print('Killing %s' % pid)
+    os.kill(int(pid), 9)