From 1db697e4ebefb27a86575c2f06de422a97a63865 Mon Sep 17 00:00:00 2001
From: Chris Church <chris@ninemoreminutes.com>
Date: Thu, 17 Nov 2016 09:09:19 -0500
Subject: [PATCH] Add multiprocessing RLock around event data output to ensure
 only one process is writing to stdout at a time.

---
 awx/lib/tower_display_callback/display.py | 16 ++++++++++------
 awx/lib/tower_display_callback/events.py  | 17 +++++++++++------
 awx/lib/tower_display_callback/module.py  | 23 ++++++++++++-----------
 awx/main/signals.py                       |  1 -
 4 files changed, 33 insertions(+), 24 deletions(-)

diff --git a/awx/lib/tower_display_callback/display.py b/awx/lib/tower_display_callback/display.py
index 7f32ca9379..128c9349c7 100644
--- a/awx/lib/tower_display_callback/display.py
+++ b/awx/lib/tower_display_callback/display.py
@@ -77,17 +77,21 @@ def display_with_context(f):
     def wrapper(*args, **kwargs):
         log_only = args[5] if len(args) >= 6 else kwargs.get('log_only', False)
         stderr = args[3] if len(args) >= 4 else kwargs.get('stderr', False)
-        fileobj = sys.stderr if stderr else sys.stdout
         event_uuid = event_context.get().get('uuid', None)
-        try:
-            if not log_only and not event_uuid:
+        with event_context.display_lock:
+            # If writing only to a log file or there is already an event UUID
+            # set (from a callback module method), skip dumping the event data.
+            if log_only or event_uuid:
+                return f(*args, **kwargs)
+            try:
+                fileobj = sys.stderr if stderr else sys.stdout
                 event_context.add_local(uuid=str(uuid.uuid4()))
                 event_context.dump_begin(fileobj)
-            return f(*args, **kwargs)
-        finally:
-            if not log_only and not event_uuid:
+                return f(*args, **kwargs)
+            finally:
                 event_context.dump_end(fileobj)
                 event_context.remove_local(uuid=None)
+
     return wrapper
 
 
diff --git a/awx/lib/tower_display_callback/events.py b/awx/lib/tower_display_callback/events.py
index 009c0c8efc..f85da9c233 100644
--- a/awx/lib/tower_display_callback/events.py
+++ b/awx/lib/tower_display_callback/events.py
@@ -22,6 +22,7 @@ import base64
 import contextlib
 import datetime
 import json
+import multiprocessing
 import os
 import threading
 import uuid
@@ -35,6 +36,9 @@ class EventContext(object):
     events and other display output methods.
     '''
 
+    def __init__(self):
+        self.display_lock = multiprocessing.RLock()
+
     def add_local(self, **kwargs):
         if not hasattr(self, '_local'):
             self._local = threading.local()
@@ -121,12 +125,13 @@ class EventContext(object):
 
     def dump(self, fileobj, data, max_width=78):
         b64data = base64.b64encode(json.dumps(data))
-        fileobj.write(u'\x1b[K')
-        for offset in xrange(0, len(b64data), max_width):
-            chunk = b64data[offset:offset + max_width]
-            escaped_chunk = u'{}\x1b[{}D'.format(chunk, len(chunk))
-            fileobj.write(escaped_chunk)
-        fileobj.write(u'\x1b[K')
+        with self.display_lock:
+            fileobj.write(u'\x1b[K')
+            for offset in xrange(0, len(b64data), max_width):
+                chunk = b64data[offset:offset + max_width]
+                escaped_chunk = u'{}\x1b[{}D'.format(chunk, len(chunk))
+                fileobj.write(escaped_chunk)
+            fileobj.write(u'\x1b[K')
 
     def dump_begin(self, fileobj):
         self.dump(fileobj, self.get_begin_dict())
diff --git a/awx/lib/tower_display_callback/module.py b/awx/lib/tower_display_callback/module.py
index daa2bb8d4a..457455e513 100644
--- a/awx/lib/tower_display_callback/module.py
+++ b/awx/lib/tower_display_callback/module.py
@@ -121,17 +121,18 @@ class BaseCallbackModule(CallbackBase):
         else:
             task = None
 
-        try:
-            event_context.add_local(event=event, **event_data)
-            if task:
-                self.set_task(task, local=True)
-            event_context.dump_begin(sys.stdout)
-            yield
-        finally:
-            event_context.dump_end(sys.stdout)
-            if task:
-                self.clear_task(local=True)
-            event_context.remove_local(event=None, **event_data)
+        with event_context.display_lock:
+            try:
+                event_context.add_local(event=event, **event_data)
+                if task:
+                    self.set_task(task, local=True)
+                event_context.dump_begin(sys.stdout)
+                yield
+            finally:
+                event_context.dump_end(sys.stdout)
+                if task:
+                    self.clear_task(local=True)
+                event_context.remove_local(event=None, **event_data)
 
     def set_playbook(self, playbook):
         # NOTE: Ansible doesn't generate a UUID for playbook_on_start so do it for them.
diff --git a/awx/main/signals.py b/awx/main/signals.py
index 7f3f8aee66..ceda8899b1 100644
--- a/awx/main/signals.py
+++ b/awx/main/signals.py
@@ -36,7 +36,6 @@ logger = logging.getLogger('awx.main.signals')
 def emit_job_event_detail(sender, **kwargs):
     instance = kwargs['instance']
     created = kwargs['created']
-    print("before created job_event_detail")
     if created:
         event_serialized = JobEventSerializer(instance).data
         event_serialized['id'] = instance.id