fix [2111536] [FAST BLOCKER] Device is soft rebooted after ending the call through voice dialer

        int surface, int num)

    : SharedBufferBase(sharedClient, surface, num), tail(0)

{

    SharedBufferStack& stack( *mSharedStack );

    int32_t avail;

    int32_t head;

    // we need to make sure we read available and head coherently,

    // w.r.t RetireUpdate.

    do {

        avail = stack.available;

        head = stack.head;

    } while (stack.available != avail);

    tail = head - avail + 1;

    if (tail < 0) {

        tail += num;

    }

}

ssize_t SharedBufferClient::dequeue()

{

    SharedBufferStack& stack( *mSharedStack );

    if (stack.head == tail && stack.available == 2) {

        LOGW("dequeue: tail=%d, head=%d, avail=%d, queued=%d",

                tail, stack.head, stack.available, stack.queued);

    }

    //LOGD("[%d] about to dequeue a buffer",

    //        mSharedStack->identity);

    DequeueCondition condition(this);

    if (err != NO_ERROR)

        return ssize_t(err);

    SharedBufferStack& stack( *mSharedStack );

    // NOTE: 'stack.available' is part of the conditions, however

    // decrementing it, never changes any conditions, so we don't need

    // to do this as part of an update.

    tail = ((tail+1 >= mNumBuffers) ? 0 : tail+1);

    LOGD_IF(DEBUG_ATOMICS, "dequeued=%d, tail=%d, %s",

            dequeued, tail, dump("").string());

    return dequeued;

}

{

    RetireUpdate update(this, mNumBuffers);

    ssize_t buf = updateCondition( update );

    LOGD_IF(DEBUG_ATOMICS, "retire=%d, %s", int(buf), dump("").string());

    LOGD_IF(DEBUG_ATOMICS && buf>=0, "retire=%d, %s", int(buf), dump("").string());

    return buf;

}