前面我們分析過了佇列的建立過程，這裡我們看下佇列的push流程，其push呼叫形式如下。

bool swoole_process->push(string $data);

下面我們看下底層實現。

static PHP_METHOD(swoole_process, push)
{
    char *data;
    zend_size_t length;

    struct
    {
        long type;
        char data[SW_MSGMAX];
    } message;

    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &data, &length) == FAILURE)
    {
        RETURN_FALSE;
    }

    if (length <= 0)
    {
        swoole_php_fatal_error(E_WARNING, "the data to push is empty.");
        RETURN_FALSE;
    }
    else if (length >= sizeof(message.data))
    {
        swoole_php_fatal_error(E_WARNING, "the data to push is too big.");
        RETURN_FALSE;
    }

    swWorker *process = swoole_get_object(getThis());

    if (!process->queue)
    {
        swoole_php_fatal_error(E_WARNING, "no msgqueue, can not use push()");
        RETURN_FALSE;
    }

    message.type = process->id;
    memcpy(message.data, data, length);

    if (swMsgQueue_push(process->queue, (swQueue_data *)&message, length) < 0)
    {
        RETURN_FALSE;
    }
    RETURN_TRUE;
}
 

int swMsgQueue_push(swMsgQueue *q, swQueue_data *in, int length)
{
    int ret;

    while (1)
    {
        ret = msgsnd(q->msg_id, in, length, q->flags);
        if (ret < 0)
        {
            SwooleG.error = errno;
            if (errno == EINTR)
            {
                continue;
            }
            else if (errno == EAGAIN)
            {
                return -1;
            }
            else
            {
                swSysError("msgsnd(%d, %d, %ld) failed.", q->msg_id, length, in->mtype);
                return -1;
            }
        }
        else
        {
            return ret;
        }
    }
    return 0;
}