nsIMessageLoop

This service allows access to the current thread’s Chromium MessageLoop
instance, with some extra sugar added. If you’re calling from C++, it may
or may not make sense for you to use this interface. If you’re calling from
JS, you don’t have a choice!

Right now, you can only call PostIdleTask(), but nothing is stopping you
from adding other methods.

nsIMessageLoop’s contractid is “@mozilla.org/message-loop;1”.

Methods

postIdleTask(task, ensureRunsAfterMS)

Posts a task to be run when this thread’s message loop is idle, or after
ensureRunsAfterMS milliseconds have elapsed. (That is, the task is
guaranteed to run /eventually/.)

Note that if the event loop is busy, we will hold a reference to the task
until ensureRunsAfterMS milliseconds have elapsed. Be careful when
specifying long timeouts and tasks which hold references to windows or
other large objects, because you can leak memory in a difficult-to-detect
way!