bitbake: cooker: Avoid eventlog variable listing lockups

If the event log is enabled and parsing the metadata triggers log messages,
the event code and deadlock. Iterating the variables inside the event handling
code causes this. SOURCE_DATE_EPOCH triggers a python function which calls
bb.debug() and can trigger a lockup as one example.

Move the code around and add it to the BuildStarted events explictly. This
does mean runs without builds no longer get variables added to the eventlog
however we can look into a more targetted version of data if/as/where neded.

(Bitbake rev: 4135a617ae16d509362b5bf56378139cdc0876d2)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 11 insertions, 25 deletions

diff --git a/bitbake/lib/bb/cooker.py b/bitbake/lib/bb/cooker.py
index d658db9bd8..c5bfef55d6 100644
--- a/bitbake/lib/bb/cooker.py
+++ b/bitbake/lib/bb/cooker.py
@@ -102,12 +102,15 @@ class CookerFeatures(object):
 
 class EventWriter:
     def __init__(self, cooker, eventfile):
-        self.file_inited = None
         self.cooker = cooker
         self.eventfile = eventfile
         self.event_queue = []
 
-    def write_event(self, event):
+    def write_variables(self):
+        with open(self.eventfile, "a") as f:
+            f.write("%s\n" % json.dumps({ "allvariables" : self.cooker.getAllKeysWithFlags(["doc", "func"])}))
+
+    def send(self, event):
         with open(self.eventfile, "a") as f:
             try:
                 str_event = codecs.encode(pickle.dumps(event), 'base64').decode('utf-8')
@@ -117,28 +120,6 @@ class EventWriter:
                 import traceback
                 print(err, traceback.format_exc())
 
-    def send(self, event):
-        if self.file_inited:
-            # we have the file, just write the event
-            self.write_event(event)
-        else:
-            # init on bb.event.BuildStarted
-            name = "%s.%s" % (event.__module__, event.__class__.__name__)
-            if name in ("bb.event.BuildStarted", "bb.cooker.CookerExit"):
-                with open(self.eventfile, "w") as f:
-                    f.write("%s\n" % json.dumps({ "allvariables" : self.cooker.getAllKeysWithFlags(["doc", "func"])}))
-
-                self.file_inited = True
-
-                # write pending events
-                for evt in self.event_queue:
-                    self.write_event(evt)
-
-                # also write the current event
-                self.write_event(event)
-            else:
-                # queue all events until the file is inited
-                self.event_queue.append(event)
 
 #============================================================================#
 # BBCooker
@@ -416,6 +397,7 @@ class BBCooker:
     def setupEventLog(self, eventlog):
         if self.eventlog and self.eventlog[0] != eventlog:
             bb.event.unregister_UIHhandler(self.eventlog[1])
+            self.eventlog = None
         if not self.eventlog or self.eventlog[0] != eventlog:
             # we log all events to a file if so directed
             # register the log file writer as UI Handler
@@ -423,7 +405,7 @@ class BBCooker:
                 bb.utils.mkdirhier(os.path.dirname(eventlog))
             writer = EventWriter(self, eventlog)
             EventLogWriteHandler = namedtuple('EventLogWriteHandler', ['event'])
-            self.eventlog = (eventlog, bb.event.register_UIHhandler(EventLogWriteHandler(writer)))
+            self.eventlog = (eventlog, bb.event.register_UIHhandler(EventLogWriteHandler(writer)), writer)
 
     def updateConfigOpts(self, options, environment, cmdline):
         self.ui_cmdline = cmdline
@@ -1404,6 +1386,8 @@ class BBCooker:
         buildname = self.databuilder.mcdata[mc].getVar("BUILDNAME")
         if fireevents:
             bb.event.fire(bb.event.BuildStarted(buildname, [item]), self.databuilder.mcdata[mc])
+            if self.eventlog:
+                self.eventlog[2].write_variables()
             bb.event.enable_heartbeat()
 
         # Execute the runqueue
@@ -1547,6 +1531,8 @@ class BBCooker:
 
         for mc in self.multiconfigs:
             bb.event.fire(bb.event.BuildStarted(buildname, ntargets), self.databuilder.mcdata[mc])
+        if self.eventlog:
+            self.eventlog[2].write_variables()
         bb.event.enable_heartbeat()
 
         rq = bb.runqueue.RunQueue(self, self.data, self.recipecaches, taskdata, runlist)