osmoutil: end_proc: wait for term in a loop

Recent commit b59b677c9b13483aac72b15f4f797863d841d958 called proc.terminate()
instead of killing right away, with a .1 second sleep. Reduce this sleep to
a minuscule first wait_time, remaining tolerant for processes that take longer.

Actually all of our current processes are very fast to terminate. This patch
was created while looking for a different problem, now that it's there we might
as well keep it.

Change-Id: I98849e4550116c5666fdf6f5d4cbb576ffa3e14a

1 files changed, 19 insertions, 5 deletions

diff --git a/osmopy/osmoutil.py b/osmopy/osmoutil.py
index 87203d5..8f0369b 100755
--- a/osmopy/osmoutil.py
+++ b/osmopy/osmoutil.py
@@ -47,13 +47,27 @@ def end_proc(proc):
         return
 
     proc.terminate()
-    time.sleep(.1)
-    rc = proc.poll()
-    if rc is not None:
-        print "Terminated child process"
-    else:
+    time_to_wait_for_term = 5
+    wait_step = 0.001
+    waited_time = 0
+    while True:
+        # poll returns None if proc is still running
+        rc = proc.poll()
+        if rc is not None:
+            break
+        waited_time += wait_step
+        # make wait_step approach 1.0
+        wait_step = (1. + 5. * wait_step) / 6.
+        if waited_time >= time_to_wait_for_term:
+            break
+        time.sleep(wait_step)
+
+    if proc.poll() is None:
+        # termination seems to be slower than that, let's just kill
         proc.kill()
         print "Killed child process"
+    elif waited_time > .002:
+        print "Terminating took %.3fs" % waited_time
     proc.wait()