improve reap_children() so that it closes all subprocess fds

2 files changed, 18 insertions, 5 deletions

diff --git a/psutil/__init__.py b/psutil/__init__.py
index 2d5c974c..9c446b53 100644
--- a/psutil/__init__.py
+++ b/psutil/__init__.py
@@ -1277,7 +1277,8 @@ class Popen(Process):
                 self.stdout.close()
             if self.stderr:
                 self.stderr.close()
-            try:  # Flushing a BufferedWriter may raise an error
+            try:
+                # Flushing a BufferedWriter may raise an error.
                 if self.stdin:
                     self.stdin.close()
             finally:
diff --git a/psutil/tests/__init__.py b/psutil/tests/__init__.py
index 7cf820cc..cf90a63c 100644
--- a/psutil/tests/__init__.py
+++ b/psutil/tests/__init__.py
@@ -264,6 +264,8 @@ def reap_children(recursive=False):
     else:
         children = []
 
+    # Terminate subprocess.Popen instances "cleanly" by closing their
+    # fds and wiat()ing for them in order to avoid zombies.
     subprocs = _subprocesses_started.copy()
     _subprocesses_started.clear()
     for subp in subprocs:
@@ -272,11 +274,21 @@ def reap_children(recursive=False):
         except OSError as err:
             if err.errno != errno.ESRCH:
                 raise
+        if subp.stdout:
+            subp.stdout.close()
+        if subp.stderr:
+            subp.stderr.close()
         try:
-            subp.wait()
-        except OSError as err:
-            if err.errno != errno.ECHILD:
-                raise
+            # Flushing a BufferedWriter may raise an error.
+            if subp.stdin:
+                subp.stdin.close()
+        finally:
+            # Wait for the process to terminate, to avoid zombies.
+            try:
+                subp.wait()
+            except OSError as err:
+                if err.errno != errno.ECHILD:
+                    raise
 
     if children:
         for p in children: