C++ (Cpp) slabs_reassign_pick_any Examples

Example #1

File: slabs.c Project: TDMangukiya/memcached

static enum reassign_result_type do_slabs_reassign(int src, int dst) {
    if (slab_rebalance_signal != 0)
        return REASSIGN_RUNNING;

    if (src == dst)
        return REASSIGN_SRC_DST_SAME;

    /* Special indicator to choose ourselves. */
    if (src == -1) {
        src = slabs_reassign_pick_any(dst);
        /* TODO: If we end up back at -1, return a new error type */
    }

    if (src < POWER_SMALLEST || src > power_largest ||
            dst < POWER_SMALLEST || dst > power_largest)
        return REASSIGN_BADCLASS;

    if (slabclass[src].slabs < 2)
        return REASSIGN_NOSPARE;

    slab_rebal.s_clsid = src;
    slab_rebal.d_clsid = dst;

    slab_rebalance_signal = 1;
    pthread_cond_signal(&slab_rebalance_cond);

    return REASSIGN_OK;
}

Example #2

File: slabs.c Project: Baoxiyi-Github/Memcached

static enum reassign_result_type do_slabs_reassign(int src, int dst) {
    if (slab_rebalance_signal != 0)
        return REASSIGN_RUNNING;

    if (src == dst)//不能相同
        return REASSIGN_SRC_DST_SAME;

    /* Special indicator to choose ourselves. */
    if (src == -1) {//客户端命令要求随机选出一个源slab class

        //选出一个页数大于1的slab class，并且该slab class不能是dst
        //指定的那个。如果不存在这样的slab class，那么返回-1
        src = slabs_reassign_pick_any(dst);
        /* TODO: If we end up back at -1, return a new error type */
    }

    if (src < POWER_SMALLEST || src > power_largest ||
        dst < POWER_SMALLEST || dst > power_largest)
        return REASSIGN_BADCLASS;

    //源slab class没有或者只有一个内存页，那么就不能分给别的slab class
    if (slabclass[src].slabs < 2)
        return REASSIGN_NOSPARE;

    //全局变量slab_rebal
    slab_rebal.s_clsid = src;//保存源slab class
    slab_rebal.d_clsid = dst;//保存目标slab class

    slab_rebalance_signal = 1;
    //唤醒slab_rebalance_thread函数的线程
    //在slabs_reassign函数中已经锁上了slabs_rebalance_lock
    pthread_cond_signal(&slab_rebalance_cond);

    return REASSIGN_OK;
}