Add third_party/pexpect

third_party/pexpect/tests/platform_checks/check2.py

+#!/usr/bin/env python
+import signal
+import os
+import time
+
+def signal_handler (signum, frame):
+        print 'Signal handler called with signal:', signum
+        print 'signal.SIGCHLD=', signal.SIGKILL
+
+# Create a child process for us to kill.
+pid = os.fork()
+if pid == 0:
+        time.sleep(10000)
+
+#signal.signal (signal.SIGCHLD, signal.SIG_IGN)
+signal.signal (signal.SIGCHLD, signal_handler)
+
+print 'Sending SIGKILL to child pid:', pid
+os.kill (pid, signal.SIGKILL)
+
+# SIGCHLD should interrupt sleep.
+# Note that this is a race.
+# It is possible that the signal handler will get called
+# before we try to sleep, but this has not happened yet.
+# But in that case we can only tell by order of printed output.
+interrupted = 0
+try:
+        time.sleep(10)
+except:
+        print 'sleep was interrupted by signal.'
+        interrupted = 1
+
+if not interrupted:
+        print 'ERROR. Signal did not interrupt sleep.'
+else:
+        print 'Signal interrupted sleep. This is good.'
+
+# Let's see if the process is alive.
+try:
+        os.kill(pid, 0)
+        print 'Child is alive. This is ambiguous because it may be a Zombie.'
+except OSError as e:
+        print 'Child appears to be dead.'
+