This will allow us to schedule these timers differently in the future.
This patch only performs the refactoring, and is not intended to change
any behavior. Specifically, this patch doesn't change the order in
which timeouts are fired -- they should still all be fired according to
the mWhen field.
The implementation works by splitting timeout storage per window into
two Timeouts objects, mNormalTimeouts and mTrackingTimeouts. The ForEach
helper methods are extended to deal with both of these objects, and as a
result, most of the algorithms operating on the list of timeouts work
correctly without any modification, with the notable exception of
RunTimeout.
In RunTimeout(), the order in which Timeout objects are processed does
matter, so for that case we use the OrderedTimeoutIterator class to
iterate over both linked lists simultaneously in the mWhen order. Also,
inserting the dummy timeout when running the timeouts is only necessary
for the linked list where the last expired timeout is coming from, so we
only inject the dummy timer into the corresponding list, therefore we
remember which list we picked the last expired timeout from when
looking for it.
This code now lives in TimeoutManager. Note that this is a transition
state, the Timeout list management code also needs to be refactored out
later.
In order to simplify the lifetime management of the new class, its
lifetime is equal to the lifetime of its containing nsGlobalWindow. In
a few places where we need to dispatch runnables to do asynchronous work
on this object, we hold the containing window alive to guarantee safety.
This patch also removes a bit of dead code that was left over from the
code removed in bug 1281793. See:
https://hg.mozilla.org/mozilla-central/rev/0ac748f4d677#l1.63
The requestIdleCallback feature behaves in many ways as setTimeout
since it takes an optional timout when the idle callback will be
called regardless of the user agent being idle or not. This means that
the same mechanisms controlling setTimeout are needed for
requestIdleCallback.
MozReview-Commit-ID: 9mESsJnUexf
The requestIdleCallback feature behaves in many ways as setTimeout
since it takes an optional timout when the idle callback will be
called regardless of the user agent being idle or not. This means that
the same mechanisms controlling setTimeout are needed for
requestIdleCallback.
MozReview-Commit-ID: 9mESsJnUexf
