In what scenario is frame->root->client empty in glusterfsd

[jifengzhou]

When reading the __iot_enqueue function of io-thread.c, I saw that there is a code to check whether frame->root->client is empty. When the client pointer is NULL, execute ctx = &conf->no_client[pri], I Want to know what scenarios will the client be NULL?

void
__iot_enqueue(iot_conf_t *conf, call_stub_t *stub, int pri)
{
client_t *client = stub->frame->root->client;
iot_client_ctx_t *ctx;

if (pri < 0 || pri >= GF_FOP_PRI_MAX)
    pri = GF_FOP_PRI_MAX - 1;

if (client) {
    ctx = iot_get_ctx(THIS, client);
    if (ctx) {
        ctx = &ctx[pri];
    }
} else {
    ctx = NULL;
}
if (!ctx) {
    ctx = &conf->no_client[pri];
}

.....

[pranithk]

When reading the __iot_enqueue function of io-thread.c, I saw that there is a code to check whether frame->root->client is empty. When the client pointer is NULL, execute ctx = &conf->no_client[pri], I Want to know what scenarios will the client be NULL?

void
__iot_enqueue(iot_conf_t *conf, call_stub_t *stub, int pri)
{
client_t *client = stub->frame->root->client;
iot_client_ctx_t *ctx;

if (pri < 0 || pri >= GF_FOP_PRI_MAX)
    pri = GF_FOP_PRI_MAX - 1;

if (client) {
    ctx = iot_get_ctx(THIS, client);
    if (ctx) {
        ctx = &ctx[pri];
    }
} else {
    ctx = NULL;
}
if (!ctx) {
    ctx = &conf->no_client[pri];
}

.....

When the fop is sent by the parent translators of io-threads.