502428 – Race condition in merge process

Bug 502428 - Race condition in merge process

Summary: Race condition in merge process

Status:	UNCONFIRMED

Alias:	None

Product:	Portage Development
Classification:	Unclassified
Component:	Core (show other bugs)
Hardware:	All Linux

Importance:	Normal normal
Assignee:	Portage team

URL:
Whiteboard:
Keywords:

Depends on:
Blocks:

Reported:	2014-02-25 19:20 UTC by bay
Modified:	2014-02-25 19:20 UTC (History)
CC List:	0 users

See Also:
Package list:
Runtime testing required:	---

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Description bay 2014-02-25 19:20:10 UTC

Looks there is a race condition in pym/portage/dbapi/_MergeProcess.py on _spawn function: if child terminate before parent we'll get this stacktrace:

Traceback (most recent call last):
  File "/usr/bin/emerge", line 50, in <module>
    retval = emerge_main()
  File "/usr/lib64/portage/pym/_emerge/main.py", line 1031, in emerge_main
    return run_action(emerge_config)
  File "/usr/lib64/portage/pym/_emerge/actions.py", line 4062, in run_action
    emerge_config.args, spinner)
  File "/usr/lib64/portage/pym/_emerge/actions.py", line 453, in action_build
    retval = mergetask.merge()
  File "/usr/lib64/portage/pym/_emerge/Scheduler.py", line 1019, in merge
    rval = self._merge()
  File "/usr/lib64/portage/pym/_emerge/Scheduler.py", line 1408, in _merge
    self._main_loop()
  File "/usr/lib64/portage/pym/_emerge/Scheduler.py", line 1385, in _main_loop
    self._event_loop.iteration()
  File "/usr/lib64/portage/pym/portage/util/_eventloop/EventLoop.py", line 268, in iteration
    if not x.callback(f, event, *x.args):
  File "/usr/lib64/portage/pym/portage/util/_async/PipeLogger.py", line 133, in _output_handler
    self._unregister_if_appropriate(event)
  File "/usr/lib64/portage/pym/_emerge/AbstractPollTask.py", line 129, in _unregister_if_appropriate
    self.wait()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 57, in wait
    self._wait_hook()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 175, in _wait_hook
    self._exit_listener_stack.pop()(self)
  File "/usr/lib64/portage/pym/_emerge/SpawnProcess.py", line 168, in _pipe_logger_exit
    self.wait()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 57, in wait
    self._wait_hook()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 175, in _wait_hook
    self._exit_listener_stack.pop()(self)
  File "/usr/lib64/portage/pym/_emerge/EbuildPhase.py", line 296, in _post_phase_exit
    self.wait()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 57, in wait
    self._wait_hook()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 175, in _wait_hook
    self._exit_listener_stack.pop()(self)
  File "/usr/lib64/portage/pym/_emerge/TaskSequence.py", line 43, in _task_exit_handler
    self.wait()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 57, in wait
    self._wait_hook()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 175, in _wait_hook
    self._exit_listener_stack.pop()(self)
  File "/usr/lib64/portage/pym/_emerge/CompositeTask.py", line 134, in _default_final_exit
    return self.wait()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 57, in wait
    self._wait_hook()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 175, in _wait_hook
    self._exit_listener_stack.pop()(self)
  File "/usr/lib64/portage/pym/_emerge/EbuildBuild.py", line 302, in _build_exit
    self.wait()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 57, in wait
    self._wait_hook()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 175, in _wait_hook
    self._exit_listener_stack.pop()(self)
  File "/usr/lib64/portage/pym/_emerge/CompositeTask.py", line 134, in _default_final_exit
    return self.wait()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 57, in wait
    self._wait_hook()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 175, in _wait_hook
    self._exit_listener_stack.pop()(self)
  File "/usr/lib64/portage/pym/_emerge/Scheduler.py", line 1330, in _build_exit
    self._task_queues.merge.add(merge)
  File "/usr/lib64/portage/pym/_emerge/SequentialTaskQueue.py", line 23, in add
    self.schedule()
  File "/usr/lib64/portage/pym/_emerge/SequentialTaskQueue.py", line 45, in schedule
    task.start()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 30, in start
    self._start()
  File "/usr/lib64/portage/pym/_emerge/PackageMerge.py", line 43, in _start
    self._start_task(task, self._default_final_exit)
  File "/usr/lib64/portage/pym/_emerge/CompositeTask.py", line 151, in _start_task
    task.start()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 30, in start
    self._start()
  File "/usr/lib64/portage/pym/_emerge/EbuildMerge.py", line 34, in _start
    self._start_task(merge_task, self._merge_exit)
  File "/usr/lib64/portage/pym/_emerge/CompositeTask.py", line 151, in _start_task
    task.start()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 30, in start
    self._start()
  File "/usr/lib64/portage/pym/portage/dbapi/_MergeProcess.py", line 60, in _start
    super(MergeProcess, self)._start()
  File "/usr/lib64/portage/pym/_emerge/SpawnProcess.py", line 140, in _start
    self._pipe_logger.start()
  File "/usr/lib64/portage/pym/_emerge/AsynchronousTask.py", line 30, in start
    self._start()
  File "/usr/lib64/portage/pym/portage/util/_async/PipeLogger.py", line 32, in _start
    encoding=_encodings['fs'], errors='strict'), mode='ab')
IOError: [Errno 2] No such file or directory: '/var/tmp/portage/net-analyzer/netcat-110-r9/temp/build.log'



Reproducible: Always

Steps to Reproduce:
1. Place the "import time; time.sleep(10)" code in the parent(just after if pid != 0)
2. Try to emerge any package
Actual Results:  
Exception

Expected Results:  
All is ok