We used a custom ThreadFactory to copy the LoggingContext to newly
created threads, but this is not sufficient since the new thread may be
cached in a thread pool and then be reused to execute further tasks. We
must copy the LoggingContext each time a task is executed in a
background thread, not only when the background thread is created.
To copy the LoggingContext when a Runnable or Callable is executed in
the background we implement LoggingContext aware wrappers for them.
We use 2 ways for executing tasks in background threads:
1. ExecutorService/ScheduledExecutorService
2. WorkQueue.Executor (custom executor)
To ensure the copying of the LoggingContext when a task is executed in
the background we now do:
1. Wrap each ExecutorService/ScheduledExecutorService with a wrapper
that wraps each Runnable/Callable that is passed in with a
LoggingContext aware wrapper.
2. Wrap each Runnable/Callable that is passed into WorkQueue.Executor
with a LoggingContext aware wrapper.
For WorkQueue.Executor we would ideally wrap the Runnable/Callable in
decorateTask but the Runnable/Callable that is being executed is
contained in a RunnableScheduledFuture and we cannot access it
(decorateTask in ScheduledThreadPoolExecutor from which we inherit
ignores the passed in Runnable and only the passed in
RunnableScheduledFuture is relevant). Also overriding the
newTaskFor(Runnable)/newTaskFor(Callable) methods does not work since
ScheduledThreadPoolExecutor is creating tasks directly without invoking
any newTaskFor method.
Change-Id: I106dcdf6478c58dfa6fe1d7952a87aa16ead1a93
Signed-off-by: Edwin Kempin <ekempin@google.com>
f59c09b924