Merge "Improve Transition GC initiation by improving the Frameworks triggering signal"

            if (mLastProcessState == processState) {

                return;

            }

            mLastProcessState = processState;

            // Do not issue a transitional GC if we are transitioning between 2 cached states.

            // Only update if the state flips between cached and uncached or vice versa

            if (ActivityManager.isProcStateCached(mLastProcessState)

                    != ActivityManager.isProcStateCached(processState)) {

                updateVmProcessState(processState);

            }

            mLastProcessState = processState;

            if (localLOGV) {

                Slog.i(TAG, "******************* PROCESS STATE CHANGED TO: " + processState

                        + (fromIpc ? " (from ipc" : ""));

    }

    /** Update VM state based on ActivityManager.PROCESS_STATE_* constants. */

    // Currently ART VM only uses state updates for Transitional GC, and thus

    // this function initiates a Transitional GC for transitions into Cached apps states.

    private void updateVmProcessState(int processState) {

        // TODO: Tune this since things like gmail sync are important background but not jank

        // perceptible.

        final int state = processState <= ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND

                ? VM_PROCESS_STATE_JANK_PERCEPTIBLE

                : VM_PROCESS_STATE_JANK_IMPERCEPTIBLE;

        // Only a transition into Cached state should result in a Transitional GC request

        // to the ART runtime. Update VM state to JANK_IMPERCEPTIBLE in that case.

        // Note that there are 4 possible cached states currently, all of which are

        // JANK_IMPERCEPTIBLE from GC point of view.

        final int state = ActivityManager.isProcStateCached(processState)

                ? VM_PROCESS_STATE_JANK_IMPERCEPTIBLE

                : VM_PROCESS_STATE_JANK_PERCEPTIBLE;

        VMRuntime.getRuntime().updateProcessState(state);

    }