void
nsBaseAppShell::ScheduleSyncSection(already_AddRefed<nsIRunnable> aRunnable,
bool aStable)
{
NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
nsIThread* thread = NS_GetCurrentThread();
// Add this runnable to our list of synchronous sections.
SyncSection* section = mSyncSections.AppendElement();
section->mStable = aStable;
section->mRunnable = aRunnable;
// If aStable is false then this synchronous section is supposed to run before
// the next event at the current nesting level. Record the event loop nesting
// level and the thread recursion level so that the synchronous section will
// run at the proper time.
if (!aStable) {
section->mEventloopNestingLevel = mEventloopNestingLevel;
nsCOMPtr<nsIThreadInternal> threadInternal = do_QueryInterface(thread);
NS_ASSERTION(threadInternal, "This should never fail!");
uint32_t recursionLevel;
if (NS_FAILED(threadInternal->GetRecursionDepth(&recursionLevel))) {
NS_ERROR("This should never fail!");
}
// Due to the weird way that the thread recursion counter is implemented we
// subtract one from the recursion level if we have one.
section->mThreadRecursionLevel = recursionLevel ? recursionLevel - 1 : 0;
}
// Ensure we've got a pending event, else the callbacks will never run.
if (!NS_HasPendingEvents(thread) && !DispatchDummyEvent(thread)) {
RunSyncSections(true, 0);
}
}
// Called from the main thread
NS_IMETHODIMP
nsBaseAppShell::OnProcessNextEvent(nsIThreadInternal *thr, bool mayWait,
uint32_t recursionDepth)
{
if (mBlockNativeEvent) {
if (!mayWait)
return NS_OK;
// Hmm, we're in a nested native event loop and would like to get
// back to it ASAP, but it seems a gecko event has caused us to
// spin up a nested XPCOM event loop (eg. modal window), so we
// really must start processing native events here again.
mBlockNativeEvent = false;
if (NS_HasPendingEvents(thr))
OnDispatchedEvent(thr); // in case we blocked it earlier
}
PRIntervalTime start = PR_IntervalNow();
PRIntervalTime limit = THREAD_EVENT_STARVATION_LIMIT;
// Unblock outer nested wait loop (below).
if (mBlockedWait)
*mBlockedWait = false;
bool *oldBlockedWait = mBlockedWait;
mBlockedWait = &mayWait;
// When mayWait is true, we need to make sure that there is an event in the
// thread's event queue before we return. Otherwise, the thread will block
// on its event queue waiting for an event.
bool needEvent = mayWait;
// Reset prior to invoking DoProcessNextNativeEvent which might cause
// NativeEventCallback to process gecko events.
mProcessedGeckoEvents = false;
if (mFavorPerf <= 0 && start > mSwitchTime + mStarvationDelay) {
// Favor pending native events
PRIntervalTime now = start;
bool keepGoing;
do {
mLastNativeEventTime = now;
keepGoing = DoProcessNextNativeEvent(false, recursionDepth);
} while (keepGoing && ((now = PR_IntervalNow()) - start) < limit);
} else {
// Avoid starving native events completely when in performance mode
if (start - mLastNativeEventTime > limit) {
mLastNativeEventTime = start;
DoProcessNextNativeEvent(false, recursionDepth);
}
}
while (!NS_HasPendingEvents(thr) && !mProcessedGeckoEvents) {
// If we have been asked to exit from Run, then we should not wait for
// events to process. Note that an inner nested event loop causes
// 'mayWait' to become false too, through 'mBlockedWait'.
if (mExiting)
mayWait = false;
mLastNativeEventTime = PR_IntervalNow();
if (!DoProcessNextNativeEvent(mayWait, recursionDepth) || !mayWait)
break;
}
mBlockedWait = oldBlockedWait;
// Make sure that the thread event queue does not block on its monitor, as
// it normally would do if it did not have any pending events. To avoid
// that, we simply insert a dummy event into its queue during shutdown.
if (needEvent && !mExiting && !NS_HasPendingEvents(thr)) {
DispatchDummyEvent(thr);
}
// We're about to run an event, so we're in a stable state.
RunSyncSections(true, recursionDepth);
return NS_OK;
}